The value of second opinions on thyroid nodule management provided via direct-to-consumer telemedicine service

PURPOSE

Second medical opinions (SMO) can improve patient outcomes and change medical decision-making. The purpose was to determine the concordance of initial management of thyroid nodules for patients seeking SMO to established management guidelines.

MATERIALS AND METHODS

Cases of patients consulting a single provider via telemedicine for SMO on the workup and management of thyroid nodule(s) were reviewed from September 2011 to February 2022. The primary outcome was the overall rate of adherence to 2015 ATA guidelines (correct/incorrect) and complete agreement (yes/no) between SMO and initial treatment team.

RESULTS

Most sought a second opinion for treatment options. Only 14 (29.2 %) cases had followed all the guidelines correctly. Living in North America compared to Asia (10/18 vs. 4/25, p = 0.004) and consulting endocrinology (11/21 vs. 3/26, p = 0.004) was associated with correct following of all guidelines. The most common violations of the guidelines were a lack of Bethesda scoring in pathology reports (31.8 %) and inappropriate initial FNA (25.5 %). The SMO was in complete agreement with the initial treatment recommendation in 31 cases (64.6 %), in partial agreement in 12 cases (25 %), and in disagreement in 5 cases (10.4 %).

CONCLUSIONS

In our study, adherence to guidelines was low. However, the SMO agreed with the workup and management of most patients, as most of this discordance with guidelines did not affect the overall treatment. The virtual second opinion consult was valuable in addressing patient-specific concerns, explaining additional treatment options, and, in a few cases, recommending against inappropriate surgical intervention.

Postoperative Use of Ketorolac Improves Pain Management and Decreases Narcotic Use Following Primary Cleft Palate Surgery

OBJECTIVE

To study the efficacy and safety profile of ketorolac in cleft palate surgery.

DESIGN

Retrospective analysis of patients who underwent primary cleft palate surgery and received either postoperative ketorolac or opioids.

SETTING

Tertiary care children's hospital.

PATIENTS, PARTICIPANTS

Eighty-nine patients enrolled who were all younger than 36 months of age, not dependent on a gastrostomy tube, with no history of bleeding disorders, and had undergone their primary cleft palate procedure by one specific surgeon between January 2010 and June 2019.

INTERVENTIONS

n/a.

MAIN OUTCOME MEASURE

Morphine equivalent dose (MED), Face, Legs, Activity, Cry, Consolability (FLACC) score, length of stay (LOS), total oral intake (mL), total oral intake/LOS, and postoperative adverse events between ketorolac and no ketorolac groups.

RESULTS

MED, FLACC score, and LOS were significantly lower in the ketorolac group compared to the no ketorolac group. One patient in the ketorolac group had a bleeding event.

CONCLUSIONS

Use of ketorolac significantly decreased narcotic usage and pain scores as reported by the FLACC score. Moreover, postoperative bleeding was rare in both ketorolac and no ketorolac groups.

Use of Crotalidae equine immune F(ab')2 antivenom for treatment of an Agkistrodon envenomation

INTRODUCTION

Anavip (F(ab')₂AV) is a lyophilized F(ab')₂ immunoglobulin fragment derived from horses immunized with venom from Bothrops asper and Crotalus durissus. It was approved by the FDA in 2015 for treatment of North American rattlesnake envenomation but not for Agkistrodon envenomation. Published data regarding the efficacy and safety of Anavip in treating Agkistrodon envenomations is limited. We present a case of a patient treated with Anavip after confirmed Agkistrodon laticinctus envenomation.

CASE DETAILS

A 77 year-old man was bitten on his fifth finger by a captive A. laticinctus. He was taken to a local emergency department where he received a 10 vial initial dose of F(ab')₂AV for pain and swelling and was transferred. At the receiving facility, his pain had improved and his swelling had not progressed. Over the next 30 h, his platelets declined to 132,000/mm³ and he received an additional 4 vials of F(ab')₂AV. The remainder of his course was unremarkable with complete recovery by 3 months.

DISCUSSION

This case provides an additional published datapoint on the use of this F(ab')₂AV in the treatment of envenomation by Agkistrodon.

The utility of intraoperative nerve monitoring in secondary and tertiary Hyperparathyroid surgery

OBJECTIVES

Recurrent laryngeal nerve (RLN) injury is a well-known complication of parathyroid surgery. Despite ample data, there is still uncertainty about the role of intraoperative monitoring (IONM) in mitigating RLN damage.

STUDY DESIGN

A retrospective review.

METHODS

We included all patients presenting for total, subtotal, or completion parathyroidectomy at a tertiary referral hospital from 2013 to 2018. Information about demographics, previous neck surgery, perioperative data, pathology, and possible RLN injury was collected. Two groups were formed for analysis: IONM vs. nonmonitored (NM).

RESULTS

105 patients underwent 107 surgeries with IONM utilized in 71 cases. The groups were similar in demographics, but significantly differed (all P < 0.05) in preincision parathyroid hormone level (IONM = 2091.44 vs NM = 1334.87), surgery type (IONM = 62.9% vs NM = 27.8% subtotal), and surgery length in minutes (IONM = 155.21 vs NM = 182.22). We observed six cases (6/71 = 8.45%) of persistent RLN complaints (three or more weeks postoperatively) and four cases (4/71 = 5.63%) of temporary complaints with the use of IONM compared with only one temporary complaint (1/36 = 2.78%) in unmonitored procedures (P = 0.129).

CONCLUSIONS

These results suggest that the use of IONM does not provide a protective effect on the RLN in patients with secondary or tertiary hyperparathyroidism undergoing total, subtotal, or completion parathyroidectomy. Prospective, randomized studies with pre- and postoperative flexible laryngoscopy are needed to explore the use of IONM in this patient population further.

Serum magnesium and the incidence of coronary artery disease over a median 27 years of follow-up in the Atherosclerosis Risk in Communities (ARIC) Study and a meta-analysis

BACKGROUND

Low serum magnesium (Mg) concentrations have been associated with higher coronary artery disease (CAD) risk. A previous Atherosclerosis Risk in Communities (ARIC) Study article that evaluated the Mg-CAD association, based on 319 events occurring over 4-7 y, identified a sex-interaction whereby the inverse Mg-CAD association was much stronger among women than men. More than 1700 additional ARIC CAD events have since accrued.

OBJECTIVE

We aimed to test our hypothesis that serum Mg is inversely and independently associated with long-term CAD risk in ARIC and in a meta-analysis with other prospective studies.

METHODS

A total of 14,446 ARIC study participants (baseline mean ± SD age: 54 ± 6 y, 57% women, 27% African American) were followed for incident CAD through 2017. CAD events were defined by myocardial infarction or CAD mortality. Serum Mg was modeled as quintiles based on mean visit 1 (1987-1989) and visit 2 (1990-1992) concentrations. Cox regression models were used. We also conducted a random-effects meta-analysis incorporating these contemporary ARIC findings.

RESULTS

Over a median follow-up of 27 y, 2131 incident CAD cases accrued. Overall, low serum Mg was associated with higher CAD risk after adjustment for demographics, lifestyle factors, and other CAD risk factors than was higher serum Mg (HR Q1 compared with Q5: 1.28; 95% CI: 1.11, 1.47; P-linear trend <0.001). The association was stronger among women (HR Q1 compared with Q5: 1.53; 95% CI: 1.22, 1.92) than men (HR: 1.11; 95% CI: 0.92, 1.34) (P-interaction = 0.05). In the meta-analysis including 5 studies, the pooled RR (95% CI) for CAD in the lowest compared with the highest circulating Mg category was 1.18 (1.06, 1.31) (I2 = 22%, P-heterogeneity = 0.27).

CONCLUSIONS

In this large community-based cohort and updated meta-analysis, low circulating Mg was associated with higher CAD risk than was higher Mg. Whether increasing Mg concentrations within healthy limits is a useful strategy for CAD prevention remains to be seen.

Supraglottoplasty in Neonates under One Month of Age

OBJECTIVES

Examine outcomes of patients 1 month of age or less who received supraglottoplasty. Demonstrate the feasibility and safety of supraglottoplasty in neonates <1 month of age.

METHODS

Charts were reviewed from 2015-2017. Patients with previously identified laryngomalacia requiring surgical intervention and age 1 month or less were identified. We collected data on age, gender, surgical technique, other airway lesions, time to extubation and discharge, and comorbidities.

RESULTS

Six patients met the inclusion criteria of which four were male and two were female. Average age at time of surgery was 19.5 days. All patients had diagnosis of laryngomalacia made on flexible or direct laryngoscopy with increased work of breathing, reports of cyanotic episodes, or oxygen desaturations. All had feeding difficulties, and three had signs and history consistent with gastroesophageal reflux. Two patients underwent supraglottoplasty by CO₂ laser treatment alone, one patient received cold steel treatment alone, and the remaining three patients received cold steel with supplemental microdebrider treatment. Out of six patients, five were extubated within 5 days of their procedure. The average time to extubation was 1.8 days. The average time to discharge was 24.25 days following surgery. Two patients required revisions.

CONCLUSIONS

Supraglottoplasty in children younger than 1 month of age is rare. Despite the rare occurrence, it appears to be feasible early in life in treating laryngomalacia. Neonates with respiratory failure, apneas, and cyanosis, or difficulty feeding due to laryngomalacia should be evaluated and treated with supraglottoplasty.

Abstract 893: MicroRNA-448 Regulates the Cardiac Sodium Channel During Ischemia

Background: The cardiac voltage-gated sodium channel ( SCN5A ; encoding Na v 1.5) plays a key role in cardiac conduction. The sodium channel is downregulated in cardiomyopathy, contributing to arrhythmic risk. In part, this downregulation is because of abnormal mRNA splicing and reduced mRNA stability. The reason for decreased mRNA stability is unclear, however.

Objective: Here, we examined whether microRNA-448 (miR-448)can contribute to SCN5A mRNA instability.

Methods: Datasets from the Gene Expression Omnibus database were utilized to screen miR-448 in human and mouse heart tissues. The relationship between SCN5A and miR-448 was predicted by three independent prediction tools. The expressions of SCN5A and miR-448 were determined by quantitative real time polymerase chain reaction. Protein levels of Na v 1.5 were determined by Western blot. The effect of miR-448 mimic on sodium current was determined in induced pluripotent stem cells-derived cardiomyocytes. Mouse myocardial infarction was created by left anterior descending coronary artery ligation.

Results: The expression of miR-448 is increased in stressed heart after myocardial infarction. The binding sequence for miR-448 is well-conserved in 3’-UTR of SCN5A and miR-448 directly bound to a consensus cis element, suppressing SCN5A expression and sodium currents. miR-448 expression wass increased by hypoxia. Activated by hypoxia, HIF1α and NF-κB activated were major transcriptional regulator for MIR448 .

Conclusion: These results indicated that miR-448 contributed to post-transcriptional modification of SCN5A . miR-448 is likely one cause of sodium channel downregulation during ischemia and may represent a target for antagomir therapy to reduce arrhythmic risk associated with cardiomyopathy..

Keywords: SCN5A, miR-448, Cardiomyocyte, Hypoxia, NF-κB, HIF1α

Trafficking of the human ether-a-go-go-related gene (hERG) potassium channel is regulated by the ubiquitin ligase rififylin (RFFL)

The QT interval is an important diagnostic feature on surface electrocardiograms because it reflects the duration of the ventricular action potential. A previous genome-wide association study has reported a significant linkage between a single-nucleotide polymorphism ∼11.7 kb downstream of the gene encoding the RING finger ubiquitin ligase rififylin (RFFL) and variability in the QT interval. This, along with results in animal studies, suggests that RFFL may have effects on cardiac repolarization. Here, we sought to determine the role of RFFL in cardiac electrophysiology. Adult rabbit cardiomyocytes with adenovirus-expressed RFFL exhibited reduced rapid delayed rectifier current (I _Kr). Neonatal rabbit cardiomyocytes transduced with RFFL-expressing adenovirus exhibited reduced total expression of the potassium channel ether-a-go-go-related gene (rbERG). Using transfections of 293A cells and Western blotting experiments, we observed that RFFL and the core-glycosylated form of the human ether-a-go-go-related gene (hERG) potassium channel interact. Furthermore, RFFL overexpression led to increased polyubiquitination and proteasomal degradation of hERG protein and to an almost complete disappearance of I _Kr, which depended on the intact RING domain of RFFL. Blocking the ER-associated degradation (ERAD) pathway with a dominant-negative form of the ERAD core component, valosin-containing protein (VCP), in 293A cells partially abolished RFFL-mediated hERG degradation. We further substantiated the link between RFFL and ERAD by showing an interaction between RFFL and VCP in vitro We conclude that RFFL is an important regulator of voltage-gated hERG potassium channel activity and therefore cardiac repolarization and that this ubiquitination-mediated regulation requires parts of the ERAD pathway.

Abstract 395: A Synonymous Coding SNP Alters SCN5A Regulation by miR-24 and Associates With Non-Arrhythmic Death in Heart Failure

Mutations disrupting SCN5A coding sequence cause inherited arrhythmias and cardiomyopathy, and SNPs linked to SCN5A splicing, localization and function associate with heart failure-related sudden cardiac death. However, the clinical relevance of SNPs that modulate SCN5A expression levels remains understudied. Recently, we generated a transcriptome-wide map of microRNA (miR) binding sites in human heart and evaluated their interface with polymorphisms. Among >500 common SNPs residing within miR target regions, we identified a synonymous SNP (rs1805126) adjacent to a miR-24 site within SCN5A coding sequence. This SNP is known to reproducibly associate with heart rhythm measurements, but is not considered to be “causal”. Here, we show that miR-24 potently suppresses SCN5A and that rs1805126 modulates this regulation. In further exploring the clinical significance of this, we found that rs1805126 minor allele homozygosity associates with decreased cardiac SCN5A expression and increased mortality in heart failure patients. Unexpectedly, this risk was not linked with arrhythmic sudden cardiac death, but rather, with clinical signs of worsening heart failure (e.g. reduced ejection fraction) and myocardial gene expression changes related to bioenergetics, inflammation and extracellular remodeling. Together, these data attribute a molecular mechanism to this firmly-established GWAS SNP and highlight a novel and surprising link between common variations in SCN5A expression and non-arrhythmic death in heart failure.

Impact of treatment crossovers on clinical outcomes in the rate and rhythm control strategies for atrial fibrillation: Insights from the AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) trial

We investigated the rates and reasons for crossover to alternative treatment strategies and its impact on mortality in patients who were enrolled in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial. Over a mean follow-up period of 3.5 years, 842 patients underwent crossover to the alternative treatment arms in AFFIRM. The rate of crossover from rhythm to rate control (594/2,033, 29.2%) was more frequent than the rate of crossover from rate to rhythm control (248/2,027, 12.2%, P < 0.0001). The leading reasons for crossover from rhythm to rate control were failure to achieve or maintain sinus rhythm (272/594, 45.8%) and intolerable adverse effects (122/594, 20.5%). In comparison, the major reasons for crossover from rate to rhythm control were failure to control atrial fibrillation symptoms (159/248, 64.1%) and intolerable adverse effects (9/248, 3.6%). This difference in crossover pattern was statistically significant (P < 0.0001). There was a significantly decreased risk of all-cause mortality (adjusted HR: 0.61, 95% CI: 0.48-0.78, P < 0.0001) and cardiac mortality (adjusted hazard ratio [HR]: 0.61, 95% confidence interval [CI]: 0.43-0.88, P = 0.008) in the subgroup of patients who crossed over from rhythm to rate control as compared to those who continued in rhythm control. There was a nonsignificant trend toward decreased all-cause (adjusted HR: 0.76, 95% CI: 0.53-1.10, P = 0.14) and cardiac mortality (adjusted HR: 0.70, 95% CI: 0.42-1.18, P = 0.18) in patients who crossed over from rate to rhythm control as compared to those who continued rate control.

Association between Heat Shock Protein-60 and Development of Atrial Fibrillation: Results from the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

During atrial fibrillation (AF), a high rate of myocyte activation causes cellular stress and initiates the process of atrial remodeling, which further promotes persistence of AF. Although heat shock proteins (HSPs) have been shown to prevent atrial remodeling and suppress the occurrence of AF in cellular and animal experimental models, increased levels of HSP-60 have been observed in patients with postoperative AF, likely reflecting a response to cellular stress. To better understand the role of HSP-60 in relation to AF, we examined the association of HSP-60 levels in relation to the future development of AF in the Multi-Ethnic Study of Atherosclerosis (MESA).

METHODS

MESA is a cohort study that recruited 6,814 participants aged 45-84 years and free of known cardiovascular disease at baseline (2000-2002) from six field centers. We investigated 983 participants, selected at random from the total cohort, who had HSP-60 measured and were free of AF at baseline. We tested the association of HSP-60 levels with the incidence of AF using multivariate Cox models after adjustment for demographics, clinical characteristics, and biomarkers.

RESULTS

During an average of 10.6 years of follow-up, 77 participants developed AF. We did not observe a significant association between the log-transformed HSP-60 levels and development of AF on either unadjusted or multivariate analysis (adjusted hazard ratio: 1.02 per unit difference on natural log scale, 95% confidence interval: 0.77-1.34 ln (ng/mL).

CONCLUSION

Contrary to the findings from the preclinical studies, which demonstrated an important role of HSP-60 in the pathogenesis of AF, we did not observe a significant association between HSP-60 and occurrence of AF.

Inactivation of Endothelial Small/Intermediate Conductance of Calcium-Activated Potassium Channels Contributes to Coronary Arteriolar Dysfunction in Diabetic Patients

Background

Diabetes is associated with coronary arteriolar endothelial dysfunction. We investigated the role of the small/intermediate (SK_Ca/IK_Ca) conductance of calcium-activated potassium channels in diabetes-related endothelial dysfunction.

Methods and Results

Coronary arterioles (80 to 150 μm in diameter) were dissected from discarded right atrial tissues of diabetic (glycosylated hemoglobin = 9.6±0.25) and nondiabetic patients (glycosylated hemoglobin 5.4±0.12) during coronary artery bypass graft surgery (n=8/group). In-vitro relaxation response of precontracted arterioles was examined in the presence of the selective SK_Ca/IK_Ca activator NS309 and other vasodilatory agents. The channel density and membrane potential of diabetic and nondiabetic endothelial cells was measured by using the whole cell patch-clamp technique. The protein expression and distribution of the SK_Ca/IK_Ca in the human myocardium and coronary arterioles was examined by Western blotting and immunohistochemistry. Our results indicate that diabetes significantly reduced the coronary arteriolar response to the SK_Ca/IK_Ca activator NS309 compared to the respective responses of nondiabetic vessels (P<0.05 versus nondiabetes). The relaxation response of diabetic arterioles to NS309 was prevented by denudation of endothelium (P=0.001 versus endothelium-intact). Diabetes significantly decreased endothelial SK_Ca/IK_Ca currents and hyperpolarization induced by the SK_Ca/IK_Ca activator NS309 as compared with that of nondiabetics. There were no significant differences in the expression and distribution of SK_Ca/IK_Ca proteins in the coronary microvessels.

Conclusions

Diabetes is associated with inactivation of endothelial SK_Ca/IK_Ca channels, which may contribute to endothelial dysfunction in diabetic patients.

Antihypertensive medications and diastolic dysfunction progression in an African American population

BACKGROUND

There have been no studies examining the association between antihypertensive medications and progression of diastolic dysfunction. The purpose of this study is to determine whether there is an association between class of antihypertensive medication and diastolic dysfunction progression in an African American population.

METHODS

A retrospective cohort study of African American patients with at least two echocardiograms demonstrating diastolic dysfunction drawn from an echocardiogram database at an academic medical center. The main outcome measures were change in diastolic function grade as a function of time and association with hypertension medication classification.

RESULTS

There were 96 African American patients in the database with 2 or more echocardiograms demonstrating diastolic dysfunction; representing 302 echocardiograms. The mean time between echocardiograms was 2.6 years. The mean age was 64.2 (±10.1) years, 78 % were women, and mean BMI 31.2 (±7.4) kg/m(2). The majority of subjects had Grade I diastolic dysfunction at their initial examination [N = 87 (90.6 %)]. Approximately 22.9 % (n = 22) of the study cohort demonstrated diastolic dysfunction progression. In multivariate analysis use of calcium channel blockers (CCB) was protective against diastolic dysfunction progression (OR for CCB users vs. non-users 0.28, 95 % confidence interval, 0.09-0.90, p < 0.05).

CONCLUSIONS

These findings suggest that use of calcium channel blockers may have a protective effect against progression of diastolic dysfunction among African American patients. Further studies are required to confirm these findings and identify specific factors that can mediate disease progression among African American individuals with hypertension, who face substantial risk of complications such as diastolic heart failure.

Particulate matter induces cardiac arrhythmias via dysregulation of carotid body sensitivity and cardiac sodium channels

The mechanistic links between exposure to airborne particulate matter (PM) pollution and the associated increases in cardiovascular morbidity and mortality, particularly in people with congestive heart failure (CHF), have not been identified. To advance understanding of this issue, genetically engineered mice (CREB(A133)) exhibiting severe dilated cardiomyopathic changes were exposed to ambient PM collected in Baltimore. CREB(A133) mice, which display aberrant cardiac physiology and anatomy reminiscent of human CHF, displayed evidence of basal autonomic aberrancies (compared with wild-type mice) with PM exposure via aspiration, producing significantly reduced heart rate variability, respiratory dysynchrony, and increased ventricular arrhythmias. Carotid body afferent nerve responses to hypoxia and hyperoxia-induced respiratory depression were pronounced in PM-challenged CREB(A133) mice, and denervation of the carotid bodies significantly reduced PM-mediated cardiac arrhythmias. Genome-wide expression analyses of CREB(A133) left ventricular tissues demonstrated prominent Na(+) and K(+) channel pathway gene dysregulation. Subsequent PM challenge increased tyrosine phosphorylation and nitration of the voltage-gated type V cardiac muscle α-subunit of the Na(+) channel encoded by SCN5A. Ranolazine, a Na(+) channel modulator that reduces late cardiac Na(+) channel currents, attenuated PM-mediated cardiac arrhythmias and shortened PM-elongated QT intervals in vivo. These observations provide mechanistic insights into the epidemiologic findings in susceptibility of human CHF populations to PM exposure. Our results suggest a multiorgan pathobiology inherent to the CHF phenotype that is exaggerated by PM exposure via heightened carotid body sensitivity and cardiac Na(+) channel dysfunction.

Efficacy of follow-up and contact tracing of women who test positive for genital tract chlamydia trachomatis prior to pregnancy termination

We examined the efficacy of follow-up, contact tracing and the need for retreatment in women who were screen-positive for genital tract Chlamydia trachomatis prior to termination of pregnancy. Eighty-six of 1363 (6.3%) women screened positive. These women were significantly younger than those who screened negative (P < 0.0001). The genitourinary medicine (GUM) clinic was notified of 73 (84.9%) screen-positive women and 41 (47.7%) attended for follow-up. Contact tracing was undertaken in 38 (92.7%) women who attended and 29 (70.7%) women who attended required retreatment for Chlamydia. The median duration between pregnancy termination and GUM clinic attendance was significantly longer in women who required retreatment compared to those who did not require retreatment (P = 0.003). In conclusion, follow-up and contact-tracing of women who screen positive for genital tract C. trachomatis was incomplete. This may substantially compromise the cost-effectiveness of a screen-and-treat programme.

Mlh1 deficiency accelerates myeloid leukemogenesis in neurofibromatosis 1 (Nf1) heterozygous mice

Defects in DNA mismatch repair (MMR) have been implicated in the genesis of a diverse set of human cancers. Recent studies have suggested that one of the targets of MMR is the neurofibromatosis 1 (NF1) gene. To evaluate the contribution of Mlh1 MMR deficiency to Nf1 tumorigenesis, Mlh1-/-;Nf1+/- mice were generated. All Mlh1-/-;Nf1+/- mice (n=21) were dead by 260 days compared to none of the Nf1+/- mice. In all, 50% of the Mlh1-/-;Nf1+/- mice were dead at 150 days compared to 252 days for Mlh1-/- mice. Nine of the Mlh1-/-;Nf1+/- mice were found to harbor intrathoracic NOS2-immunoreactive myeloid leukemias similar to the hematopoietic malignancies observed in older Nf1+/- mice. As expected, significant microsatellite instability was observed in six of six tumors and neurofibromin expression was lost in all tumors analysed. These results suggest that MMR deficiency can accelerate myeloid leukemogenesis in Nf1+/- mice, presumably by inactivating Nf1 gene expression.

Bacterial pathogens of otitis media and sinusitis: detection in the nasopharynx with selective agar media

Carriage rates for the bacterial pathogens associated with otitis media (Streptococcus pneumoniae [SP], Hemophilus influenzae [HI], and Moraxella catarrhalis [MC]) are of interest. Culture on three selective agars was compared with culture on two standard agars to determine the more accurate method for detection of these species in the nasopharynx of healthy children. Weekly samples were obtained in winter from 18 healthy children (ages 1 through 9 years) as part of a longitudinal study. A 0.1-mL sample of 116 nasopharyngeal aspirate/washes was inoculated onto each of five agars. Two were standard (sheep blood and chocolate), and three were selective (blood with gentamicin for SP; chocolate with vancomycin, bacitracin, and clindamycin for HI; blood with amphotericin B, vancomycin, trimethoprim, and acetazolamide for MC). One technician read the standard plates and another the selective; both were blinded to the results of the other. SP was found in 44% of samples with selective agar versus 25% with standard agar; HI was found in 31% with selective versus 9% with standard; MC was found in 56% with selective versus 37% with standard. Overall, 80% of samples had one or more pathogens detected with selective agars as compared with 58% with standard agars (P =.0004). Selective agars were more accurate than standard agars for detecting otitis pathogens in the nasopharynx, where they are a common part of normal flora in healthy children.

Abortion training in U.S. obstetrics and gynecology residency programs, 1998

CONTEXT

Since the late 1970s, the number of obstetrics and gynecology residency programs providing abortion training in the United States has steadily decreased. Given the documented shortage of abortion providers, assessing and ensuring the availability of abortion training in graduate medical education is critical.

METHODS

In 1998, the National Abortion Federation surveyed the 261 accredited U.S. residency programs in obstetrics and gynecology, and analyzed the availability of first- and second-trimester abortion training.

RESULTS

Of the 179 programs that responded to the survey, 81% reported that they offer first-trimester abortion training--46% routinely and 34% as an elective. Seventy-four percent of programs offer second-trimester training--44% routinely and 29% as an elective. Some programs that do not offer training give residents the option of obtaining it elsewhere. While 26% of programs indicated that all residents in their programs receive abortion training, 40% said that fewer than half are trained, including 14% that train no residents. The operating room is the most common training site: Fifty-nine percent of programs reported that abortion training takes place in the operating room.

CONCLUSIONS

After a decades-long decline in the availability of abortion training, opportunities for abortion training have increased. However, there is reason to be cautious in interpreting these results, including possible response bias and pressure to report the availability of abortion training because of new guidelines from the Accreditation Council for Graduate Medical Education.

Mlh1 deficiency enhances several phenotypes of Apc(Min)/+ mice

Defects in APC and DNA mismatch repair genes are associated with a strong predisposition to colon cancer in humans, and numerous mouse strains with mutations in these genes have been generated. In this report we describe the phenotype of Min/+ Mlh1-/- mice. We find that these doubly mutant mice develop more than three times the number of intestinal adenomas compared to Min/+ Mlh1+/+ or +/- mice but that these tumors do not show advanced progression in terms of tumor size or histological appearance. Full length Apc protein was not detected in the tumor cells from Min/+ Mlh1-/- mice. Molecular analyses indicated that in many tumors from Min/+ Mlh1-/- mice, Apc was inactivated by intragenic mutation. Mlh1 deficiency in Min/+ mice also led to an increase in cystic intestinal crypt multiplicity as well as enhancing desmoid tumorigenesis and epidermoid cyst development. Thus, Mlh1 deficiency influences the somatic events involved in the development of most of the phenotypes associated with the Min mutation. Oncogene (2000).

Predominant interactions between mu-conotoxin Arg-13 and the skeletal muscle Na+ channel localized by mutant cycle analysis

High-affinity mu-conotoxin block of skeletal muscle Na+ channels depends on an arginine at position 13 (Arg-13). To understand both the mechanism of toxin interaction and the general structure of its binding site in the channel mouth, we examined by thermodynamic mutant cycle analysis the interaction between the critical Arg-13 and amino acid residues known to be in the channel's outer vestibule. Arg-13 interacts specifically with domain II Glu-758 with energy of about -3.0 kcal/mol, including both electrostatic and nonelectrostatic components, and with Glu-403 with energy of about -2.0 kcal/mol. Interactions with the other charged residues in the outer vestibule were shown to be almost entirely electrostatic, because these interactions were maintained when Arg-13 was replaced by lysine. These results place the bound Arg-13 at the channel mouth adjacent to the P (pore) loops of domains I and II. Distance estimates based on interaction energies suggest that the charged vestibule residues are in relative positions similar to those of the Lipkind-Fozzard vestibule model [Lipkind, G. M., and Fozzard, H. A. (1994) Biophys. J. 66, 1-13]. Kinetic analysis suggests that Arg-13 interactions are partially formed in the ligand-channel transition state.

Hospital-acquired urinary tract infections in the pediatric patient: a prospective study

To determine through a prospective study the characteristics of hospital-acquired urinary tract infections (HAUTI) in children, 525 children subjected to bladder catheterization during a hospital admission were identified through surveillance of 12,316 admissions during a 24-month period. Urine culture results were available for 296 (56.4%) of the catheterized patients. In addition 12 noncatheterized children with a documented HAUTI were identified. The clinical courses of all patients with a HAUTI were followed for at least 6 months after their last HAUTI during the study period. Forty-four patients, 1 week to 17 years of age, with 1 or more HAUTI during a hospital unit admission were identified. A total of 51 HAUTI occurred. Thirty-nine (76.5%) of the infections occurred in patients subjected to catheterization. Thirty-two (10.8%) of 296 catheterized patients developed a HAUTI. Forty-three (84.3%) of the 51 infections were single organism infections. One HAUTI was associated with a wound infection with the same organism and one with a concurrent bacteremia with the same organism. Relapses were seen after 4 HAUTI. One reinfection was identified. There were no deaths directly associated with a HAUTI. Hospitalized children subjected to urinary tract catheterization are at significant risk for HAUTI. Complications are infrequent and not life-threatening.

Carbon-isotope discrimination by leaves of Flaveria species exhibiting different amounts of C3-and C 4-cycle co-function

Carbon-isotope ratios were examined as δ(13)C values in several C3, C4, and C3-C4 Flaveria species, and compared to predicted δ(13)C, values generated from theoretical models. The measured δ(13)C values were within 4‰ of those predicted from the models. The models were used to identify factors that contribute to C3-like δ(13)C values in C3-C4 species that exhibit considerable C4-cycle activity. Two of the factors contributing to C3-like δ(13)C values are high CO2 leakiness from the C4 pathway and pi/pa values that were higher than C4 congeners. A marked break occurred in the relationship between the percentage of atmospheric CO2 assimilated through the C4 cycle and the δ(13)C value. Below 50% C4-cycle assimialtion there was no significant relationship between the variables, but above 50% the δ(13)C values became less negative. These results demonstrate that the level of C4-cycle expression can increase from, 0 to 50% with little integration of carbon transfer from the C4 to the C3 cycle. As expression increaces above 50%, however, increased integration of C3- and C4-cycle co-function occurs.

Use of an anaerobic culture jar in processing pediatric throat cultures

Two hundred consecutive throat cultures from a Pediatric Walk-in Clinic were processed, using both aerobic and anaerobic culture techniques. The 35 aerobic isolates of group A beta-hemolytic streptococci (BHS) were all confirmed anaerobically as well, and there were two additional isolates detected only by the anaerobic technique. Of these 37 bacitracin-sensitive isolates, only 24 (65%) could be identified at 24 hours using the aerobic technique, compared to 29 (78%) using the anaerobic technique. In contrast to this relatively small effect upon the isolation of group A BHS, the yield of BHS from groups B, C, F, and G was more than doubled by the anaerobic technique. The confusion engendered by the improved detection of these bacitracin-resistant BHS using the anaerobic technique offset the small advantage in thoroughness and speed of detection of group A organisms. On this account, until more is known about the possible significance of isolating nongroup A BHS in the pharynx, the advisability of using an anaerobic culture jar to process pediatric throat cultures remains uncertain.

Effect of dredge spoil deposition on fecal coliform counts in sediments at a disposal site

The most-probable-number of fecal coliforms in sediments was monitored at the New London dump site in Long Island Sound during the deposition of dredge spoil from the Thames River. Although the geometric mean for fecal coliforms at five stations in the river was 14,000/100 ml before dredging commenced, the deposition of this material did not increase the incidence of fecal coliforms at 17 spoil stations and 13 control stations in the disposal and surrounding areas. Fecal coliforms appear to occur only in the surface sediment material and are diluted by the subsurface material during the dredging operation. Fecal coliform analyses of bottom waters during high and low tides indicated that the flow of water from the Thames River played a major role in determining the most-probable-number of fecal coliforms in the sediments at the disposal site.