Validating the Modified McGill Thyroid Nodule Score for Assessment of Preoperative Risk of Pediatric Thyroid Malignancy

OBJECTIVE

The McGill Thyroid Nodule Score (MTNS) is a preoperative tool used to predict the risk for well-differentiated thyroid cancer in adults. It was developed by a multidisciplinary team using established evidence-based risk factors for thyroid cancer. The modified McGill Thyroid Nodule Score (mMTNS) was developed to predict malignancy risk in children. A pilot study suggested the mMTNS was able to assess malignancy risk in children with indeterminate cytology on fine needle aspiration (FNA). This study seeks to validate these findings.

METHODS

Retrospective chart review identified subjects who underwent FNA biopsy and subsequent resection. Each patient was assigned a score to compare to final pathology. Statistical analysis was performed with SPSS. All tests were 2-tailed and statistical significance defined p < 0.05. Logistic regression used to determine predictive values of scores.

RESULTS

46 patients ≤21 years of age underwent resection of a thyroid nodule. Female predominance of 85% (n = 39). 78% (n = 36) of patients had palpable nodule. 65% (n = 30) found to have benign pathology and 35% (n = 16) found to have malignancy. Malignant nodules associated with greater mean mMTNS compared to benign [13.63 vs 7.23]. An mMTNS greater >12 had sensitivity of 86.7%, specificity of 90.3%, positive predictive value of 81.3%, and negative predictive value of 93.3%.

CONCLUSION

Our data suggests the mMTNS continues to be a useful adjunct in predicting malignancy risk of pediatric thyroid nodules. An mMTNS >12 has a high risk for malignancy, which can aid in counseling and clinical decision making, particularly when there is indeterminate cytology on FNA.

LEVEL OF EVIDENCE

IV.

A Critical Appraisal of the July Effect: Evaluating Complications Following Pancreaticoduodenectomy

BACKGROUND

Reports of higher rates of medical errors in the month of July have generated concern regarding major surgery at academic institutions early in the yearly promotion cycle. This study was designed to evaluate perioperative outcomes in patients undergoing pancreaticoduodenectomy (PD) at different times of the year.

MATERIALS AND METHODS

Outcomes were retrospectively evaluated for patients treated in July versus the rest of the year and in the first quarter (July-September) versus the remaining quarters. The primary outcome was operative morbidity as measured by Clavien-Dindo grade, a classification system of surgical complications. Secondary outcomes included mortality, operative blood loss, pancreatic fistula formation, delayed gastric emptying, intraabdominal abscess, anastomotic leak, reoperation, and other variables of interest.

RESULTS

From January 2003 to September 2015, 472 patients underwent PD by a single academic surgeon. Overall, 77.1% of PDs were performed for malignancy. The number of patients did not significantly vary by month or by quarter. The incidence of major morbidity (Clavien-Dindo grade ≥ III) in patients who had a PD was 12.2% in July and 17.5% in all other months (P = 0.79). The rate of pancreatic fistula, intraabdominal abscess, reoperation, readmission, and mortality did not differ significantly by month or by quarter (P > 0.05 for all).

CONCLUSIONS

The current study does not find any correlation between time of year and operative morbidity or mortality, suggesting that PD can be safely performed irrespective of timing.

Pediatric intussusception in Uganda: differences in management and outcomes with high-income countries

PURPOSE

In high-income countries the presentation and treatment of intussusception is relatively rapid, and most cases are correctable with radiographically-guided reduction. In low-income countries, many delays affect outcomes and surgical intervention is required. This study characterizes the burden and outcome of pediatric intussusception in Uganda.

METHODS

Prospective case series of intussusception cases from May 2015 to July 2016 at a tertiary referral hospital in Uganda.

RESULTS

Forty patients were included in the study. Male to female ratio was 3:2. Average duration of symptoms before presentation was 4.5 days. Median duration of symptoms in referred patients was 4 days and 2 days in non-referred patients (P value 0.0009). All 40 patients underwent surgical treatment: 25% had resection and enterostomy, 15% had resection and primary anastomosis, 2.5% had resection, primary anastomosis and enterostomy and 57.5% underwent manual reduction. Mortality was 32% and febrile patients on admission were 20 times more likely to die (P value 0.040).

CONCLUSION

Intussusception carries a high operative and mortality rate in Uganda. Referred patients presented later than non-referred patients to health facilities. Fever on examination at admission was positively associated with mortality. This disease remains a target for quality metrics in global pediatric surgery.

TYPE OF STUDY

Diagnostic study.

LEVEL OF EVIDENCE

III.

Association of Lowering Default Pill Counts in Electronic Medical Record Systems With Postoperative Opioid Prescribing

Importance

Reliance on prescription opioids for postprocedural analgesia has contributed to the opioid epidemic. With the implementation of electronic medical record (EMR) systems, there has been increasing use of computerized order entry systems for medication prescriptions, which is now more common than handwritten prescriptions. The EMR can autopopulate a default number of pills prescribed, and 1 potential method to alter prescriber behavior is to change the default number presented via the EMR system.

Objective

To investigate the association of lowering the default number of pills presented when prescribing opioids in an EMR system with the amount of opioid prescribed after procedures.

Design, Setting, and Participants

A prepost intervention study was conducted to compare postprocedural prescribing patterns during the 3 months before the default change (February 18 to May 17, 2017) with the 3 months after the default change (May 18 to August 18, 2017). The setting was a multihospital health care system that uses Epic EMR (Hyperspace 2015 IU2; Epic Systems Corporation). Participants were all patients in the study period undergoing 1 of the 10 most common operations and discharged by postoperative day 1.

Intervention

The default number of opioid pills autopopulated in the EMR when prescribing discharge analgesia was lowered from 30 to 12.

Main Outcomes and Measures

Linear regression estimating the change in the median number of opioid pills and the total dose of opioid prescribed was performed. Opioid doses were converted into morphine milligram equivalents (MME) for comparison. The frequency of patients requiring analgesic prescription refills was also evaluated.

Results

There were 1447 procedures (mean [SD] age, 54.4 [17.3] years; 66.9% female) before the default change and 1463 procedures (mean [SD] age, 54.5 [16.4] years; 67.0% female) after the default change. After the default change, the median number of opioid pills prescribed decreased from 30 (interquartile range, 15-30) to 20 (interquartile range, 12-30) per prescription (P < .001). The percentage of prescriptions written for 30 pills decreased from 39.7% (554 of 1397) before the default change to 12.9% (183 of 1420) after the default change (P < .001), and the percentage of prescriptions written for 12 pills increased from 2.1% (29 of 1397) before the default change to 24.6% (349 of 1420) after the default change (P < .001). Regression analysis demonstrated a decrease of 5.22 (95% CI, -6.12 to -4.32) opioid pills per prescription after the default change, for a total decrease of 34.41 (95% CI, -41.36 to -27.47) MME per prescription. There was no statistical difference in opioid refill rates (3.0% [4 of 135] before the default change vs 1.5% [2 of 135] after the default change, P = .41).

Conclusions and Relevance

Lowering the default number of opioid pills prescribed in an EMR system is a simple, effective, cheap, and potentially scalable intervention to change prescriber behavior and decrease the amount of opioid medication prescribed after procedures.

Whole-Exome Sequencing of Syndromic Adrenocortical Carcinoma Reveals Distinct Mutational Profile From Sporadic ACC

Next-generation sequencing has provided genetic profiles of a large number of sporadic adrenocortical carcinomas (ACCs), but the applicability of these results to ACC cases associated with tumor predisposition syndromes is unclear. Although the germline features of these syndromes have been well described, the somatic mutational landscape of the tumors they give rise to is less clear. Our group obtained germline and tumor tissue from a pediatric patient who developed ACC during her first year of life, which was treated successfully. She was subsequently diagnosed with additional tumors later in childhood. Whole exome sequencing analysis was performed followed by in silico protein function prediction, revealing a probably deleterious germline TP53 L265P mutation. The somatic mutational burden was comparable between the index case and a previously published cohort of 40 sporadic cases, but the mutational spectrum was distinct in terms of raw base-change frequency as well as in a trinucleotide context-specific analysis. No canonical somatic genetic drivers of ACC were identified in the reported case, suggesting that syndromic adrenocortical tumors may represent a genetically distinct entity from sporadic tumors.

Prediction of Postoperative Surgical Risk: A Needs Assessment for a Medical Student Curriculum

OBJECTIVE

Medical students' abilities to predict postoperative complications and death are unknown. We hypothesize that medical students will lack confidence in determining surgical risk and will significantly overestimate surgical risk for post-operative morbidities and mortality.

DESIGN

Participants were invited to participate in an electronic, anonymous survey to assess their ability to predict surgical risk. The survey presented 7 complex clinical scenarios representative of a diverse general surgery practice. Participants were asked to assess the likelihood of different morbidities and mortality on a 0-100% scale, and predictions were compared to the ACS NSQIP risk calculator.

SETTING

Yale School of Medicine, New Haven, Connecticut; Tertiary medical center PARTICIPANTS: Third year medical students on their surgery clerkship as well as general surgery residents were invited to participate.

RESULTS

Most students were not confident about predicting postoperative complications (83.3%) or mortality (70.8%). Most students did not feel that the surgery clerkship adequately prepared them to assess surgical risk (69.6%). When compared to surgical residents for most presented cases (57% of cases), students and residents similarly overestimated postoperative morbidities and mortality. Estimates varied significantly, with wide 95% confidence intervals. Only 17% of NSQIP predicted estimates fell within the 95% confidence intervals.

CONCLUSIONS

Medical students overestimate morbidity and mortality following surgery in complex patients. Additionally, they lack confidence in their ability to predict surgical complications. A formal curriculum for risk prediction is needed for medical students.

Beyond 250: A Comprehensive Strategy to Maximize the Operative Experience for Junior Residents

OBJECTIVES

Among surgical educators, duty-hour restrictions led to concern regarding the adequacy of operative experience during residency, especially for junior residents. The American Board of Surgery recently instituted guidelines mandating "a minimum of 250 operations by the end of the PGY-2 year". A series of programmatic and institutional changes were implemented at our institution to augment the junior resident operative experience and to exceed compliance with this mandate.

METHODS

Operative data from Accreditation Council for Graduate Medical Education case logs for categorical and nondesignated preliminary interns from our large academic surgical residency were identified for 5 consecutive academic years, 2011 until 2016. American Board of Surgery In-Training Examination (ABSITE) scores were collected anonymously. The program systematically instituted the following changes: night float minimization, identification of new surgical opportunities, augmenting use of midlevel care providers, identification of rotations with suboptimal operative experiences, maximizing rotations with involvement of junior residents in the operating room, and systematic review of junior case logs.

RESULTS

After implementation, average total cases for residents completing postgraduate year (PGY)-2 increased from 176 to 330 (p < 0.001). Specifically, there was an 18% increase for interns (p = 0.059) and a 118% increase for PGY-2 residents (p < 0.001). There were statistically significant increases in skin and soft tissue cases, vascular cases, endoscopy, and complex laparoscopic cases. Average case volumes for senior residents did not change. Night float time was significantly decreased (5.7 vs 3.4 wk; p = 0.04). ABSITE scores were not significantly changed during this time.

CONCLUSIONS

Before implementation of these interventions, our program would have had 0% compliance with the 250 junior resident case rule. Within 12 months of implementation, total case volumes for residents completing PGY-2 increased by 88%-exceeding minimum standards. Overall, 100% programmatic compliance was achieved. Our program's experience exemplifies how mandates from the American Board of Surgery can lead to programmatic changes that improve the experience of surgical house officers.

Assessing Interest and Barriers for Resident and Faculty Involvement in Global Surgery

BACKGROUND

Multiple institutions have developed international electives and sustainable global surgery initiatives to facilitate clinical, research, and outreach opportunities with hospitals in resource-poor areas. Despite increasing interest among programs, many institutions have not successfully reached potential involvement.

OBJECTIVE

This study evaluates the experiences of Yale residents and faculty, measures interest in the development of an international surgical elective, and enumerates barriers to developing or participating in these opportunities. This was performed to develop a formalized elective and assess interest and capacity for surgical global health initiatives, as a seemingly increasing number of trainee applicants and residents were expressing interest in working in resource-poor settings.

METHODS

Electronic survey of Yale Surgery residents and faculty analyzed using SPSS and Graphpad Prism.

RESULTS

Among residents, previous global experience correlates with current interest in international opportunities, with 100% remaining interested, and 78% of those without prior experience also expressing interest (p = 0.018). Barriers to pursuing these activities included the use of vacation time, funding, scheduling, family obligations, and concern for personal safety. Among faculty, 28% of respondents have been involved internationally, and most (86%) expressed interest in additional opportunities and all were willing to take residents. Barriers to faculty participation included funding, relative value unit target reduction, protected time, and the desire for institutional support for such activities.

CONCLUSIONS

A substantial proportion of residents and faculty have experience in global health and motivation to pursue additional opportunities. The main barriers to participation are not a lack of interest, but rather needs for funding support, protected time, and institutional recognition of academic contributions. These findings are being used to develop a global surgery elective and establish long-term partnerships with international colleagues.

Trainees as Agents of Change in the Opioid Epidemic: Optimizing the Opioid Prescription Practices of Surgical Residents

OBJECTIVE

Opioid abuse has become an epidemic in the United States, causing nearly 50,000 deaths a year. Postoperative pain is an unavoidable consequence of most surgery, and surgeons must balance the need for sufficient analgesia with the risks of overprescribing. Prescribing narcotics is often the responsibility of surgical residents, yet little is known about their opioid-prescribing habits, influences, and training experience.

DESIGN

Anonymous online survey that assessed the amounts of postoperative opioid prescribed by residents, including type of analgesia, dosage, and number of pills, for a series of common general surgery procedures. Additional questions investigated influences on opioid prescription, use of nonnarcotic analgesia, degree of engagement in patient education on opioids, and degree of training received on analgesia and opioid prescription.

SETTING

Accreditation Council for Graduate Medical Education accredited general surgery program at a university-based tertiary hospital.

PARTICIPANTS

Categorical and preliminary general surgery residents of all postgraduate years.

RESULTS

The percentage of residents prescribing opioids postprocedure ranged from 75.5% for incision and drainage to 100% for open hernia repair. Residents report prescribing 166.3 morphine milligram equivalents of opioid for a laparoscopic cholecystectomy, yet believe patients will only need an average of 113.9 morphine milligram equivalents. The most commonly reported influences on opioid-prescribing habits include attending preference (95.2%), concern for patient satisfaction (59.5%), and fear of potential opioid abuse (59.5%). Only 35.8% of residents routinely perform a narcotic risk assessment before prescribing and 6.2% instruct patients how to properly dispose of excess opioids. More than 90% of residents have not had formal training in best practices of pain management or opioid prescription.

CONCLUSION AND RELEVANCE

Surgical trainees are relying almost exclusively on opioids for postoperative analgesia, often in excessive amounts. Residents are heavily influenced by their superiors, but are not receiving formal opioid-prescribing education, pointing to a great need for increased resident education on postoperative pain and opioid management to help change prescribing habits.

Pancreaticoduodenectomy Can be Performed Safely with Rare Employment of Surgical Drains

Use of drain remains frequent following pancreaticoduodenectomy (PD) due to concern for postoperative pancreatic fistula (POPF) and anastomotic leak development. Despite controversy, a recent randomized trial suggested omitting drainage would result in a large increase in operative mortality. This study sought to comprehensively examine the effects of forgoing drainage in the large cohort of patients undergoing PD. A prospective cohort study of two consecutive groups undergoing PD was constructed. The initial group had operative drains placed in cases subjectively concerning for POPF development; the second cohort did not undergo operative drainage. Outcomes including POPF incidence, need for reintervention, and overall morbidity were examined. A total of 106 patients were evaluated in two consecutive cohorts of 53; in the first group, 30 per cent had operative drains placed; 22.6 per cent developed POPF versus 7.5 per cent of patients in the no drainage group (P = 0.06). Despite this, no significant difference in major morbidity (Clavien ≥3, 20.8% versus 17.0%) or need for procedural reintervention (18.9% versus 15.1%) was observed. A subsequent validation cohort of 237 additional patients where drains were used only in exceptional circumstances was examined. Operative drains were placed in only 3 per cent of patients (n = 7) and 90-day mortality was 1.3 per cent (n = 3). Incidence of POPF was 8.0 per cent and the overall major complication rate was 14.8 per cent. Given such findings, it appears that drainage after PD can be avoided resulting in acceptable operative morbidity and mortality in most cases.

A novel FOXO1-mediated dedifferentiation blocking role for DKK3 in adrenocortical carcinogenesis

Background

Dysregulated WNT signaling dominates adrenocortical malignancies. This study investigates whether silencing of the WNT negative regulator DKK3 (Dickkopf-related protein 3), an implicated adrenocortical differentiation marker and an established tumor suppressor in multiple cancers, allows dedifferentiation of the adrenal cortex.

Methods

We analyzed the expression and regulation of DKK3 in human adrenocortical carcinoma (ACC) by qRT-PCR, immunofluorescence, promoter methylation assay, and copy number analysis. We also conducted functional studies on ACC cell lines, NCI-H295R and SW-13, using siRNAs and enforced DKK3 expression to test DKK3’s role in blocking dedifferentiation of adrenal cortex.

Results

While robust expression was observed in normal adrenal cortex, DKK3 was down-regulated in the majority (>75%) of adrenocortical carcinomas (ACC) tested. Both genetic (gene copy loss) and epigenetic (promoter methylation) events were found to play significant roles in DKK3 down-regulation in ACCs. While NCI-H295R cells harboring β-catenin activating mutations failed to respond to DKK3 silencing, SW-13 cells showed increased motility and reduced clonal growth. Conversely, exogenously added DKK3 also increased motility of SW-13 cells without influencing their growth. Enforced over-expression of DKK3 in SW-13 cells resulted in slower cell growth by an extension of G1 phase, promoted survival of microcolonies, and resulted in significant impairment of migratory and invasive behaviors, largely attributable to modified cell adhesions and adhesion kinetics. DKK3-over-expressing cells also showed increased expression of Forkhead Box Protein O1 (FOXO1) transcription factor, RNAi silencing of which partially restored the migratory proficiency of cells without interfering with their viability.

Conclusions

DKK3 suppression observed in ACCs and the effects of manipulation of DKK3 expression in ACC cell lines suggest a FOXO1-mediated differentiation-promoting role for DKK3 in the adrenal cortex, silencing of which may allow adrenocortical dedifferentiation and malignancy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3152-5) contains supplementary material, which is available to authorized users.

Pancreaticoduodenectomy Can Be Performed Safely with Rare Employment of Surgical Drains

Use of drain remains frequent following pancreaticoduodenectomy (PD) due to concern for postoperative pancreatic fistula (POPF) and anastomotic leak development. Despite controversy, a recent randomized trial suggested omitting drainage would result in a large increase in operative mortality. This study sought to comprehensively examine the effects of forgoing drainage in the large cohort of patients undergoing PD. A prospective cohort study of two consecutive groups undergoing PD was constructed. The initial group had operative drains placed in cases subjectively concerning for POPF development; the second cohort did not undergo operative drainage. Outcomes including POPF incidence, need for reintervention, and overall morbidity were examined. A total of 106 patients were evaluated in two consecutive cohorts of 53; in the first group, 30 per cent had operative drains placed; 22.6 per cent developed POPF versus 7.5 per cent of patients in the no drainage group (P = 0.06). Despite this, no significant difference in major morbidity (Clavien ≥3, 20.8% versus 17.0%) or need for procedural reintervention (18.9% versus 15.1%) was observed. A subsequent validation cohort of 237 additional patients where drains were used only in exceptional circumstances was examined. Operative drains were placed in only 3 per cent of patients (n = 7) and 90-day mortality was 1.3 per cent (n = 3). Incidence of POPF was 8.0 per cent and the overall major complication rate was 14.8 per cent. Given such findings, it appears that drainage after PD can be avoided resulting in acceptable operative morbidity and mortality in most cases.

Pediatric incidental appendectomy: a systematic review

Incidental appendectomy is the removal of the vermiform appendix accompanying another operation, without evidence of acute appendicitis. It is generally performed to eliminate the risk of future appendicitis. The risks and benefits of incidental appendectomy during various operations in children have been debated for over a century, but need to be revisited in light of innovations in medical practice, including minimally invasive surgery, improved imaging techniques, and use of the appendix as a tubular conduit for reconstruction. A detailed review was undertaken of the techniques, pathology, risks of appendectomy, utility of the appendix, and incidental appendectomy in the treatment of specific pediatric medical conditions. A comprehensive literature search was performed, and retrieved results were reviewed for relevance to the topic. The decision to perform a pediatric incidental appendectomy relies on informed consideration of the individual patient's co-morbid conditions, the indication for the initial operation, the future utility of the appendix, and the risk of future appendiceal pathology. The discussion includes a variety of situations and comorbid conditions that may influence a surgeon's decision to perform incidental appendectomy.

Novel somatic mutations in primary hyperaldosteronism are related to the clinical, radiological and pathological phenotype

Aldosterone-producing adenomas (APAs) and bilateral adrenal hyperplasia are important causes of secondary hypertension. Somatic mutations in KCNJ5, CACNA1D, ATP1A1, ATP2B3 and CTNNB1 have been described in APAs.

OBJECTIVE

To characterize clinical-pathological features in APAs and unilateral adrenal hyperplasia, and correlate them with genotypes.

DESIGN

Retrospective study.

SUBJECTS AND MEASUREMENTS

Clinical and pathological characteristics of 90 APAs and seven diffusely or focally hyperplastic adrenal glands were reviewed, and samples were examined for mutations in known disease genes by Sanger or exome sequencing.

RESULTS

Mutation frequencies were as follows: KCNJ5, 37·1%; CACNA1D, 10·3%; ATP1A1, 8·2%; ATP2B3, 3·1%; and CTNNB1, 2·1%. Previously unidentified mutations included I157K, F154C and two insertions (I150_G151insM and I144_E145insAI) in KCNJ5, all close to the selectivity filter, V426G_V427Q_A428_L433del in ATP2B3 and A39Efs*3 in CTNNB1. Mutations in KCNJ5 were associated with female and other mutations with male gender (P = 0·007). On computed tomography, KCNJ5-mutant tumours displayed significantly greater diameter (P = 0·023), calculated area (P = 0·002) and lower precontrast Hounsfield units (P = 0·0002) vs tumours with mutations in other genes. Accordingly, KCNJ5-mutant tumours were predominantly comprised of lipid-rich fasciculata-like clear cells, whereas other tumours were heterogeneous (P = 5 × 10(-6) vs non-KCNJ5 mutant and P = 0·0003 vs wild-type tumours, respectively). CACNA1D mutations were present in two samples with hyperplasia without adenoma.

CONCLUSIONS

KCNJ5-mutant tumours appear to be associated with fasciculata-like clear cell predominant histology and tend to be larger with a characteristic imaging phenotype. Novel somatic KCNJ5 variants likely cause adenomas by loss of potassium selectivity, similar to previously described mutations.

DNA copy amplification and overexpression of SLC12A7 in adrenocortical carcinoma

BACKGROUND

Overexpression of Solute carrier family 12 member 7 (SLC12A7) promotes tumor aggressiveness in various cancers. Previous studies have identified the 5p15.33 region, containing the SLC12A7 locus, as being amplified frequently in adrenocortical carcinoma (ACC). Copy number amplifications (CNAs) may alter gene expression levels and occur frequently in ACC; however, SLC12A7 gene amplifications or expression levels have not been studied in ACC.

METHODS

Fifty-five cases of clinically well-characterized ACCs were recruited for this study. Whole-exome sequencing was used to predict CNAs in 19 samples. CNA analysis was performed on an expanded cohort of 26 samples with the use of TaqMan Copy Number Assays. SLC12A7 mRNA expression was analyzed in 32 samples with real-time quantitative polymerase chain reaction and protein expression was assessed by immunohistochemistry. SLC12A7 CNAs and expression patterns were evaluated for correlation with patient and tumor characteristics.

RESULTS

Whole-exome sequencing and TaqMan Copy Number Assays demonstrated SLC12A7 amplifications in 68.4% and 65.4% of ACCs tested, respectively. Furthermore, SLC12A7 copy gains were associated with increased gene expression (P < .05) and non-functional tumors (P < .05). SLC12A7 gene expression levels were increased in ACCs compared with normal adrenal tissue (P < .05).

CONCLUSION

SLC12A7 gene amplification and overexpression occurs frequently in ACCs and may represent a novel molecular event associated with ACC.

Characterization of the mutational landscape of anaplastic thyroid cancer via whole-exome sequencing

Anaplastic thyroid carcinoma (ATC) is a frequently lethal malignancy that is often unresponsive to available therapeutic strategies. The tumorigenesis of ATC and its relationship to the widely prevalent well-differentiated thyroid carcinomas are unclear. We have analyzed 22 cases of ATC as well as 4 established ATC cell lines using whole-exome sequencing. A total of 2674 somatic mutations (121/sample) were detected. Ontology analysis revealed that the majority of variants aggregated in the MAPK, ErbB and RAS signaling pathways. Mutations in genes related to malignancy not previously associated with thyroid tumorigenesis were observed, including mTOR, NF1, NF2, MLH1, MLH3, MSH5, MSH6, ERBB2, EIF1AX and USH2A; some of which were recurrent and were investigated in 24 additional ATC cases and 8 ATC cell lines. Somatic mutations in established thyroid cancer genes were detected in 14 of 22 (64%) tumors and included recurrent mutations in BRAF, TP53 and RAS-family genes (6 cases each), as well as PIK3CA (2 cases) and single cases of CDKN1B, CDKN2C, CTNNB1 and RET mutations. BRAF V600E and RAS mutations were mutually exclusive; all ATC cell lines exhibited a combination of mutations in either BRAF and TP53 or NRAS and TP53. A hypermutator phenotype in two cases with >8 times higher mutational burden than the remaining mean was identified; both cases harbored unique somatic mutations in MLH mismatch-repair genes. This first comprehensive exome-wide analysis of the mutational landscape of ATC identifies novel genes potentially associated with ATC tumorigenesis, some of which may be targets for future therapeutic intervention.

Frequent silencing of RASSF1A via promoter methylation in follicular thyroid hyperplasia: a potential early epigenetic susceptibility event in thyroid carcinogenesis

IMPORTANCE

Follicular thyroid hyperplasia (FTH) refers to enlargement of the thyroid gland due to cellular hyperplasia. It is frequently encountered in clinical practice in nontoxic uninodular or multinodular goiter. The genetic and epigenetic events associated with the origin and malignant potential of FTH are poorly understood.

OBJECTIVE

To analyze FTH samples for known recurrent genetic and epigenetic driver events in thyroid neoplasms such as activating mutations in proto-oncogenes BRAF and NRAS and promoter hypermethylation of tumor suppressor genes CDKN2A, PTEN, and RASSF1A.

DESIGN, SETTING, AND PARTICIPANTS

Clinical characteristics and thyroid specimens were prospectively obtained from 43 patients who underwent thyroid surgery at Yale-New Haven Hospital.

MAIN OUTCOMES AND MEASURES

Presence of BRAF(V600E) and NRAS codon 61 mutations were assessed in FTH. Methylation status of CDKN2A, PTEN, and RASSF1A gene promoters in FTH, follicular thyroid adenoma, and follicular thyroid carcinoma was quantified. Regulation of RASSF1A messenger RNA (mRNA) and protein expression and its potential neoplastic role in FTH were examined.

RESULTS

An exploratory cohort of FTH (n = 10) was negative for BRAF(V600E) and NRAS codon 61 mutations. In contrast, epigenetic analysis displayed significant promoter hypermethylation of the tumor-suppressor gene RASSF1A in 6 FTH samples (60%) compared with their adjacent normal tissue (P = .01). The overall genome CpG methylation and promoter methylation of PTEN and CDKN2A were unaffected in the lesions. Further analysis of an expanded cohort of patients with FTH (n = 23), follicular thyroid adenoma (n = 10), and follicular thyroid carcinoma (n = 10) showed RASSF1A promoter hypermethylation in 14 (61%), 9 (90%), and 7 (70%), respectively (P < .001). The overall hypermethylation level in FTH showed a statistically significant inverse correlation with RASSF1A mRNA expression (P = .005). Immunohistochemistry demonstrated minimal or no protein expression in most FTH samples studied. To explore the potential neoplastic contribution of RASSF1A downregulation, we analyzed the expression pattern of thyroid proliferation markers Ki-67 and NF-κB in representative samples. Although Ki-67 expression was undetectable, similar to normal tissue, FTH samples expressed high levels of NF-κB, similar to the expression levels in thyroid tumors.

CONCLUSIONS AND RELEVANCE

We demonstrate silencing of tumor suppressor RASSF1A in a subset of FTH in the absence of other known thyroid cancer-associated genetic and epigenetic changes. Silencing of RASSF1A and concurrent NF-κB activation demonstrate that a subset of FTH shares epigenetic changes and downstream signaling events associated with malignant lesions, suggesting that FTH may have the potential to be a premalignant lesion.

Whole-exome sequencing characterizes the landscape of somatic mutations and copy number alterations in adrenocortical carcinoma

CONTEXT

Adrenocortical carcinoma (ACC) is a rare and lethal malignancy with a poorly defined etiology, and the molecular genetics of ACC are incompletely understood.

OBJECTIVE

To utilize whole-exome sequencing for genetic characterization of the underlying somatic mutations and copy number alterations present in ACC.

DESIGN

Screening for somatic mutation events and copy number alterations (CNAs) was performed by comparative analysis of tumors and matched normal samples from 41 patients with ACC.

RESULTS

In total, 966 nonsynonymous somatic mutations were detected, including 40 tumors with a mean of 16 mutations per sample and one tumor with 314 mutations. Somatic mutations in ACC-associated genes included TP53 (8/41 tumors, 19.5%) and CTNNB1 (4/41, 9.8%). Genes with potential disease-causing mutations included GNAS, NF2, and RB1, and recurrently mutated genes with unknown roles in tumorigenesis comprised CDC27, SCN7A, and SDK1. Recurrent CNAs included amplification at 5p15.33 including TERT (6/41, 14.6%) and homozygous deletion at 22q12.1 including the Wnt repressors ZNRF3 and KREMEN1 (4/41 9.8% and 3/41, 7.3%, respectively). Somatic mutations in ACC-established genes and recurrent ZNRF3 and TERT loci CNAs were mutually exclusive in the majority of cases. Moreover, gene ontology identified Wnt signaling as the most frequently mutated pathway in ACCs.

CONCLUSIONS

These findings highlight the importance of Wnt pathway dysregulation in ACC and corroborate the finding of homozygous deletion of Wnt repressors ZNRF3 and KREMEN1. Overall, mutations in either TP53 or CTNNB1 as well as focal CNAs at the ZNRF3 or TERT loci denote mutually exclusive events, suggesting separate mechanisms underlying the development of these tumors.

Heart block and acute kidney injury due to hyperparathyroidism-induced hypercalcemic crisis

We describe a patient who presented with multi-system organ failure due to extreme hypercalcemia (serum calcium 19.8 mg/dL), resulting from primary hyperparathyroidism. He was found to have a 4.8 cm solitary atypical parathyroid adenoma. His course was complicated by complete heart block, acute kidney injury, and significant neurocognitive disturbances. Relevant literature was reviewed and discussed. Hyperparathyroidism-induced hypercalcemic crisis (HIHC) is a rare presentation of primary hyperparathyroidism and only a small minority of these patients develop significant cardiac and renal complications. In cases of HIHC, a multidisciplinary effort can facilitate rapid treatment of life-threatening hypercalcemia and definitive treatment by surgical resection. As such, temporary transvenous cardiac pacing and renal replacement therapy can provide a life-saving bridge to definitive parathyroidectomy in cases of HIHC.

The activating TERT promoter mutation C228T is recurrent in subsets of adrenal tumors

The telomerase reverse transcriptase gene (TERT) encodes the reverse transcriptase component of the telomerase complex, which is essential for telomere stabilization and cell immortalization. Recent studies have demonstrated a transcriptional activation role for the TERT promoter mutations C228T and C250T in many human cancers, as well as a role in aggressive disease with potential clinical applications. Although telomerase activation is known in adrenal tumors, the underlying mechanisms are not established. We assessed C228T and C250T TERT mutations by direct Sanger sequencing in tumors of the adrenal gland, and further evaluated potential associations with clinical parameters and telomerase activation. A total of 199 tumors were evaluated, including 34 adrenocortical carcinomas (ACC), 47 adrenocortical adenomas (ACA), 105 pheochromocytomas (PCC; ten malignant and 95 benign), and 13 abdominal paragangliomas (PGL; nine malignant and four benign). TERT expression levels were determined by quantitative RT-PCR. The C228T mutation was detected in 4/34 ACCs (12%), but not in any ACA (P=0.028). C228T was also observed in one benign PCC and in one metastatic PGL. The C250T mutation was not observed in any case. In the ACC and PGL groups, TERT mutation-positive cases exhibited TERT expression, indicating telomerase activation; however, since expression was also revealed in TERT WT cases, this could denote additional mechanisms of TERT activation. To conclude, the TERT promoter mutation C228T is a recurrent event associated with TERT expression in ACCs, but rarely occurs in PGL and PCC. The involvement of the TERT gene in ACC represents a novel mutated gene in this entity.

Recurrent activating mutation in PRKACA in cortisol-producing adrenal tumors

Adrenal tumors autonomously producing cortisol cause Cushing syndrome^1–4. Exome sequencing of 25 tumor-normal pairs revealed two groups. Eight tumors (including 3 carcinomas) had many somatic copy number variants (CNV+) with frequent deletion of CDC42 and CDKN2A, amplification of 5q31.2, and protein-altering mutations in TP53 and RB1. Seventeen (all adenomas) had no CNVs (CNV-), TP53 or RB1 mutations. Six of these had known gain of function mutations in CTNNB1^5,6 (beta-catenin) or GNAS^7,8 (Gα_s), Six others had somatic p.Leu206Arg mutations in PRKACA (protein kinase A (PKA) catalytic subunit). Further sequencing identified this mutation in 13 of 63 tumors (35% of adenomas with overt CS). PRKACA, GNAS and CTNNB1 mutations were mutually exclusive. Leu206 directly interacts with PKA’s regulatory subunit, PRKAR1A^9,10. PRKACA^L206R loses PRKAR1A binding, increasing phosphorylation of downstream targets. PKA activity induces cortisol production and cell proliferation^11–15, providing a mechanism for tumor development. These findings define distinct mechanisms underlying adrenal cortisol-producing tumors.

Epigenetic silencing of RASSF1A deregulates cytoskeleton and promotes malignant behavior of adrenocortical carcinoma

Background

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy with high mutational heterogeneity and a generally poor clinical outcome. Despite implicated roles of deregulated TP53, IGF-2 and Wnt signaling pathways, a clear genetic association or unique mutational link to the disease is still missing. Recent studies suggest a crucial role for epigenetic modifications in the genesis and/or progression of ACC. This study specifically evaluates the potential role of epigenetic silencing of RASSF1A, the most commonly silenced tumor suppressor gene, in adrenocortical malignancy.

Results

Using adrenocortical tumor and normal tissue specimens, we show a significant reduction in expression of RASSF1A mRNA and protein in ACC. Methylation-sensitive and -dependent restriction enzyme based PCR assays revealed significant DNA hypermethylation of the RASSF1A promoter, suggesting an epigenetic mechanism for RASSF1A silencing in ACC. Conversely, the RASSF1A promoter methylation profile in benign adrenocortical adenomas (ACAs) was found to be very similar to that found in normal adrenal cortex. Enforced expression of ectopic RASSF1A in the SW-13 ACC cell line reduced the overall malignant behavior of the cells, which included impairment of invasion through the basement membrane, cell motility, and solitary cell survival and growth. On the other hand, expression of RASSF1A/A133S, a loss-of-function mutant form of RASSF1A, failed to elicit similar malignancy-suppressing responses in ACC cells. Moreover, association of RASSF1A with the cytoskeleton in RASSF1A-expressing ACC cells and normal adrenal cortex suggests a role for RASSF1A in modulating microtubule dynamics in the adrenal cortex, and thereby potentially blocking malignant progression.

Conclusions

Downregulation of RASSF1A via promoter hypermethylation may play a role in the malignant progression of adrenocortical carcinoma possibly by abrogating differentiation-promoting RASSF1A- microtubule interactions.

Obesity in people with learning disabilities: possible causes and reduction interventions

Obesity is more prevalent in people with learning disabilities than the general population, contributing towards health inequalities and higher risk of cardiovascular and cerebrovascular disease. This article discusses possible causes of this higher prevalence and examines interventions to reduce obesity and associated risks. It also outlines key points to consider when dealing with adults with learning disabilities, such as assessing mental capacity to consent to specific interventions. The importance of multidisciplinary team working with a range of professionals and specialists, and ensuring a consistent approach are also stressed.

Natriuretic peptide guanylyl cyclase receptors in the kidney of the Japanese eel, Anguilla japonica

Natriuretic peptides are linked to osmoregulation, cardiovascular and volume regulation in fishes. The peptides bind to two guanylyl-cyclase-linked receptors, natriuretic peptide receptor-A (NPR-A) and NPR-B, to elicit their effects. Atrial natriuretic peptide (ANP) binds principally to NPR-A, whereas C-type natriuretic peptide (CNP) binds to NPR-B. The teleost kidney has an important role in the maintenance of fluid and electrolyte balance; therefore, the location of NPR-A and NPR-B in the kidney could provide insights into the functions of natriuretic peptides. This study used homologous, affinity purified, polyclonal antibodies to NPR-A and NPR-B to determine their location in the kidney of the Japanese eel, Anguilla japonica. Kidneys from freshwater and seawater acclimated animals were fixed overnight in 4% paraformaldehyde before being paraffin-embedded and immunostained. NPR-A immunoreactivity was found on the apical membrane of proximal tubule 1 and the vascular endothelium including the glomerular capillaries. In contrast, NPR-B immunoreactivity was located on the smooth muscle of blood vessels including the glomerular afferent and efferent arterioles, and on smooth muscle tissue surrounding the collecting ducts. No difference in the distribution of NPR-A and NPR-B was observed between freshwater and seawater kidneys. Immunoreactivity was not observed in any tissue in which the antibodies had been preabsorbed. In addition, there was no difference in NPR-A and NPR-B mRNA expression between freshwater-acclimated and seawater-acclimated eels. These results suggest that, although utilizing the same second messenger system, ANP and CNP act on different targets within the kidney and presumably elicit different effects.

Cell cycle regulation of cyclin-dependent kinases in tobacco cultivar Bright Yellow-2 cells

Plants possess two major classes of cyclin-dependent kinases (CDK) with cyclin-binding motifs PSTAIRE (CDK-a) and PPTA/TLRE (CDK-b). Tobacco (Nicotiana tabacum L. cv Bright Yellow-2) cells are the most highly synchronizable plant culture, but no detailed analysis of CDK activities has been reported in this system. Here we describe isolation of new PPTALRE CDKs (Nicta;CdkB1) from Bright Yellow-2 cells and present detailed analysis of the mRNA, protein and kinase activity levels of CdkB1, and the PSTAIRE CDKA during the growth and cell cycles. CdkA and CdkB1 transcripts are more abundant in exponential than in stationary phase cells, but the two genes show strikingly different regulation during the cell cycle. CdkA mRNA and protein accumulate during G1 in cells re-entering the cell cycle, and immunoprecipitated histone H1 kinase activity increases at the G1/S boundary. Aphidicolin synchronized cells show the highest CDKA-associated histone H1 kinase activity during S-G2 phases, although CdkA mRNA and protein levels are not significantly regulated. In contrast, CdkB1 transcripts are present at very low levels until S phase and CDKB1 protein and kinase activity is almost undetectable in G1. CdkB1 mRNA accumulates through S until M phase and its associated kinase activity peaks at the G2/M boundary, confirming that transcription of PPTALRE CDKs is cell cycle regulated. We suggest that CDKA kinase activity likely plays roles at the G1/S phase boundary, during S phase, and at the G2/M phase transition, and that CDKB1 kinase activity is present only at G2/M.

Regulation of both gene expression and protein stability provides genetically assisted target evaluation (GATE) for microbial target validation

The attempt to develop novel antibiotics, active against organisms resistant to current therapies, has led researchers to seek and explore new drug targets. The rapid sequencing and analysis of entire microbial genomes has identified large numbers of genes that may be sufficiently different from their human counterparts to be exploited as targets for antimicrobial treatment. As a first step, the importance of the various putative targets for microbial growth and survival must be assessed. Emerging validation technologies are becoming increasingly sophisticated and, in certain cases, allow prioritisation of the best targets. In this paper, genetically assisted target evaluation (GATE) is introduced as a versatile target validation technology. GATE concomitantly manipulates both synthesis and stability of the targeted protein using copper ions as an effector. This technology allows rapid quantitation of the lethal consequences of inactivation of targeted gene products in Saccharomyces cerevisiae. Additional tools can then be applied to extend these results into pathogenic organisms, such as Candida albicans.

Strategic planning applied to quality in asthma management for children

This strategic plan translates the HCHP vision statement into a working plan for one major clinical condition--asthma in children. It is a working plan for clinicians and managers across specialties and levels. The results of the projects will improve in a measurable way significant clinical practice and outcomes, in keeping with the FY 1993 strategic goals.

Patient reports about ambulatory care

To improve, managers need information on the process of care and patient satisfaction. The study described in this article validates a survey for assessing the process of care and satisfaction with ambulatory care visits and illustrates how this information can be used to estimate the impact of different visit processes on patient satisfaction.

The Arabidopsis D-type cyclins CycD2 and CycD3 both interact in vivo with the PSTAIRE cyclin-dependent kinase Cdc2a but are differentially controlled

D-type cyclins (CycD) play key roles in linking the Arabidopsis cell cycle to extracellular and developmental signals, but little is known of their regulation at the post-transcriptional level or of their cyclin-dependent kinase (CDK) partners. Using new antisera to CycD2 and CycD3, we demonstrate that the CDK partner of these Arabidopsis cyclins is the PSTAIRE-containing CDK Cdc2a. Previous analysis has shown that transcript levels of CycD2 and CycD3 are regulated in response to sucrose levels and that both their mRNA levels and kinase activity are induced with different kinetics during the G(1) phase of cells reentering the division cycle from quiescence. Here we analyze the protein levels and kinase activity of CycD2 and CycD3. We show that CycD3 protein and kinase activity parallel the abundance of its mRNA and that CycD3 protein is rapidly lost from cells in stationary phase or following sucrose removal. In contrast to both CycD3 and the regulation of its own mRNA levels, CycD2 protein is present at constant levels. CycD2 kinase activity is regulated by sequestration of CycD2 protein in a form inaccessible to immunoprecipitation and probably not complexed to Cdc2a.

Sugar control of the plant cell cycle: differential regulation of Arabidopsis D-type cyclin gene expression

In most plants, sucrose is the major transported carbon source. Carbon source availability in the form of sucrose is likely to be a major determinant of cell division, and mechanisms must exist for sensing sugar levels and mediating appropriate control of the cell cycle. We show that sugar availability plays a major role during the G(1) phase by controlling the expression of CycD cyclins in Arabidopsis. CycD2 mRNA levels increase within 30 min of the addition of sucrose; CycD3 is induced after 4 h. This corresponds to induction of CycD2 expression early in G(1) and CycD3 expression in late G(1) near the S-phase boundary. CycD2 and CycD3 induction is independent both of progression to a specific point in the cell cycle and of protein synthesis. Protein kinase activity of CycD2- and CycD3-containing cyclin-dependent kinases is consistent with the observed regulation of their mRNA levels. CycD2 and CycD3 therefore act as direct mediators of the presence of sugar in cell cycle commitment. CycD3, but not CycD2, expression responds to hormones, for which we show that the presence of sugars is required. Finally, protein phosphatases are shown to be involved in regulating CycD2 and CycD3 induction. We propose that control of CycD2 and CycD3 by sucrose forms part of cell cycle control in response to cellular carbohydrate status.

Cyclin D control of growth rate in plants

The mechanisms by which plants modulate their growth rate in response to environmental and developmental conditions are unknown, but are presumed to involve specialized regions called meristems where cell division is concentrated. The possible role of cell division in influencing meristem activity and overall plant growth rate is controversial, with a prevailing view that cell division is secondary to higher order meristem controls. Here we show that a reduction in the length of the cell-cycle G1 phase and faster cell cycling occur when the rate of cell division in transgenic tobacco plants is increased by the plant D-type cyclin CycD2 (ref. 8). The plants have normal cell and meristem sizes, but elevated overall growth rates, an increased rate of leaf initiation and accelerated development in all stages from seedling to maturity. We conclude that cell division is a principal determinant of meristem activity and overall growth rate, and propose that modulation of plant growth rate is achieved through regulation of G1.

Paxillin association in vitro with integrin cytoplasmic domain peptides

Short cytoplasmic domains of integrin heterodimers are crucial for transduction of signals generated by adhesion of cells to the extracellular matrix. Here, we describe the use of peptides mimicking the intracellular tails of integrin alpha5beta1 to assay in vitro associations with cytoskeletal proteins. Our results suggest that the focal adhesion protein, paxillin, may interact directly with the intracellular region of the integrin beta1 subunit. Paxillin is known to form stable complexes with several signaling molecules, including focal adhesion kinase. Physical interaction between paxillin and the beta1 cytoplasmic domain suggests a model in which paxillin may function as a key intermediary in integrin-mediated signal transduction.

Diagnosis of malignant hyperthermia: a comparison of the in vitro contracture test with the molecular genetic diagnosis in a large pedigree

Malignant hyperthermia (MH) is an inherited skeletal muscle disorder and is one of the major causes of death resulting from anaesthesia. MH is currently diagnosed by the in vitro contracture test performed on a muscle biopsy. Genetic linkage analysis on an Irish MH pedigree showed that when the thresholds for the standardised European protocol for MHS diagnosis was applied, linkage between the MHS phenotype and the RYR1 locus was excluded. When we raised the threshold values for assignment of MHS status and assumed MHN diagnosis in subjects where this threshold was not attained, tight linkage between MHS and RYR1 markers was observed, suggesting that MHS is linked to the RYR1 locus in this pedigree. Confirmation of these results was borne out by the fact that all of the MHS patients in the pedigree exceeding the raised threshold carried the known MHS Gly341Arg RYR1 mutation. The results obtained could be explained (1) by false positive diagnosis of MHS in the recombinant subjects, (2) by the presence of a mutation in a predisposing gene other than RYR1, or (3) by the presence of mild subclinical myopathies. The implications of these results for heterogeneity studies is discussed.

Relationship of anatomic disease to appropriateness ratings of coronary angiography

BACKGROUND

At Harvard Community Health Plan (HCHP), Brookline, Mass, a mixed-model health maintenance organization (HMO), coronary angiography is performed at numerous community and tertiary-level teaching hospitals.

OBJECTIVE

To determine the appropriateness of coronary angiography within HCHP according to RAND (1992) criteria and to examine the relationship between the appropriateness rating and (1) the clinical indication for catheterization and (2) the extent of anatomic disease.

METHOD

A retrospective, randomized hospital medical record review of 292 patients enrolled in HCHP who underwent coronary angiography in 1992, stratified by four distinct HCHP subgroups.

RESULTS

Of the coronary angiographies reviewed, 78% were rated appropriate, 16% uncertain, and only 6% inappropriate across the entire sample. Ratings were comparable in all subdivisions of HCHP despite an incidence rate of catheterization in one of the three HMO divisions that was 60% and 40% higher than in the other two divisions. The lowest appropriateness ratings were for Asymptomatic patients (43%) and those with Chest Pain of Uncertain Origin (35%) (capital letters refer to the RAND clinical indication criteria mentioned above). A rating of necessity was not a better discriminator of anatomic disease than a rating of appropriateness alone: 82% and 84%, respectively, were found to have disease by angiography.

CONCLUSION

The low HCHP rate of inappropriateness for coronary angiography is comparable with the RAND 1992 New York State data. This finding, coupled with marked differences in the incidence rate of this procedure among the HCHP divisions, is consistent with either major differences in the sickness of the HMO's sub-populations or, more likely, a lack of specificity of the RAND criteria for coronary angiography.

Characterization of biphenyl catabolic genes of gram-positive polychlorinated biphenyl degrader Rhodococcus sp. strain RHA1

Rhodococcus sp. strain RHA1 is a gram-positive polychlorinated biphenyl (PCB) degrader which can degrade 10 ppm of PCB48 (equivalent to Aroclor1248), including tri-, tetra-, and pentachlorobiphenyls, in a few days. We isolated the 7.6-kb EcoRI-BamHI fragment carrying the biphenyl catabolic genes of RHA1 and determined their nucleotide sequence. On the basis of deduced amino acid sequence homology, we identified six bph genes, bphA1A2A3A4, bphB, and bphC, that are responsible for the initial three steps of biphenyl degradation. The order of bph genes in RHA1 is bphA1A2A3A4-bphC-bphB. This gene order differs from that of other PCB degraders reported previously. The amino acid sequences deduced from the RHA1 bph genes have a higher degree of homology with the tod genes from Pseudomonas putida F1 (49 to 79%) than with the bph genes of Pseudomonas sp. strains KF707 and KKS102 (30 to 65%). In Escherichia coli, bphA gene activity was not observed even when expression vectors were used. The activities of bphB and bphC, however, were confirmed by observing the transformation of biphenyl to a meta-cleavage compound with the aid of benzene dioxygenase activity that complemented the bphA gene activity (S. Irie, S. Doi, T. Yorifuji, M. Takagi, and K. Yano, J. Bacteriol. 169:5174-5179, 1987). The expected products of the cloned bph genes, except bphA3, were observed in E. coli in an in vitro transcription-translation system. Insertion mutations of bphA1 and bphC of Rhodococcus sp. strain RHA1 were constructed by gene replacement with cloned gene fragments.(ABSTRACT TRUNCATED AT 250 WORDS)

Peptide ligands for integrin alpha v beta 3 selected from random phage display libraries

The integrin alpha v beta 3 binds promiscuously to cell-adhesive proteins: vitronectin, fibronectin, and several others containing the RGD motif. We have explored molecular recognition by alpha v beta 3 through selection of ligands from large random libraries of peptides displayed on phage. Ligands bound by alpha beta 3 consisted primarily of RGD peptides; however, these peptides showed considerable heterogeneity with respect to the identities of amino acids flanking RGD. The tolerance of alpha v beta 3 for RGD peptides of diverse composition is consistent with its role in vivo as a versatile receptor for RGD-containing extracellular matrix proteins. Peptide ligands for alpha v beta 3 also included a novel binding sequence, identical to a tetrapeptide found in vitronectin, which is a candidate for a synergistic site in this adhesive protein that may act in concert with RGD to promote molecular recognition.

Mutation screening of the RYR1 gene in malignant hyperthermia: detection of a novel Tyr to Ser mutation in a pedigree with associated central cores

The ryanodine receptor gene (RYR1) has been shown to be mutated in a small number of malignant hyperthermia (MH) pedigrees. Missense mutations in this gene have also been identified in two families with central core disease (CCD), a rare myopathy closely associated with MH. In an effort to identify other RYR1 mutations responsible for MH and CCD, we used a SSCP approach to screen the RYR1 gene for mutations in a family exhibiting susceptibility to MH (MHS) where some of the MHS individuals display core regions in their muscle. Sequence analysis of a unique aberrant SSCP has allowed us to identify a point mutation cosegregating with MHS in the described family. The mutation changes a conserved tyrosine residue at position 522 to a serine residue. This mutation is positioned relatively close to five of the six MHS/CCD mutations known to date and provides further evidence that MHS/CCD mutations may cluster in the amino terminal region of the RYR1 protein.

Assessing the needs of women and clinicians for the management of menopause in an HMO

OBJECTIVE

To determine the perceived needs of perimenopausal women regarding the management of menopause and the resource needs of the clinicians who treat them.

SETTING

A large staff and group network model health maintenance organization (HMO) in New England.

PARTICIPANTS

A random sample of 790 perimenopausal women aged 45-60 years who were members of the HMO in 1991, and a random sample of 180 clinicians in internal medicine, family practice, and obstetrics/gynecology practicing in the HMO during 1991.

METHOD

Mailed surveys of women and clinicians were designed to assess possible needs and attitudes that could lead to the improvement of care for menopausal women. The chi-square test was used to determine differences in perceived needs and satisfaction levels among women with differences in self-reported menopausal status. The Kruskal-Wallis one-way analysis of variance and the Mann-Whitney U test were used in the clinician survey to test for differences among specialties and between genders.

RESULTS

The key findings include that: 1) most (81%) of the women wanted to see a woman clinician, 2) many (50%) were interested in a menopause support group, 3) 30% reported that their care for menopause had been fair to poor, 4) only 55% of the primary care specialists (including internal medicine and family practice) reported high confidence in their abilities to treat menopause, compared with 68% of the obstetric/gynecology clinicians, and 5) 56% of the clinicians surveyed said that support from the HMO to their practices for the treatment of menopause was fair to poor.

CONCLUSIONS

There is an opportunity for better care for perimenopausal women as reported by two sources, HMO clinicians and members. To provide this care, clinicians may need explicit guidelines as well as administrative supports such as educational materials and specialty access. Since the capability for menopausal care from clinicians in obstetrics/gynecology is perceived to be higher than that from primary care clinicians, an opportunity for cross-specialty collaboration and training may exist.

Detection of a novel common mutation in the ryanodine receptor gene in malignant hyperthermia: implications for diagnosis and heterogeneity studies

Malignant hyperthermia (MH) is a potentially fatal autosomal dominant disorder of skeletal muscle and is triggered in susceptible people by all commonly used inhalational anaesthetics. To date, the ryanodine receptor gene (RYR1) has been shown to be mutated in a small number of malignant hyperthermia susceptible (MHS) cases. To determine if a common RYR1 mutation exists that might account for a significant number of MHS cases, we have investigated the RYR1 gene in unrelated patients for the presence of new mutations by the single-stranded conformation polymorphism method and have identified a novel Gly341Arg mutation which accounts for approximately 10% of Caucasian MHS cases. The implications of this common mutation in MHS diagnosis and heterogeneity studies are discussed.

Mutations in the ryanodine receptor gene in central core disease and malignant hyperthermia

Central core disease (CCD) of muscle is an inherited myopathy which is closely associated with malignant hyperthermia (MH) in humans. CCD has recently been shown to be tightly linked to the ryanodine receptor gene (RYR1) and mutations in this gene are known to be present in MH. Mutation screening of RYR1 has led to the identification of two previously undescribed mutations in different CCD pedigrees. One of these mutations was also detected in an unrelated MH pedigree whose members are asymptomatic of CCD. The data suggest a model to explain how a single mutation may result in two apparently distinct clinical phenotypes.

Localization of the malignant hyperthermia susceptibility locus to human chromosome 19q12-13.2

Malignant hyperthermia (MH) is an inherited human skeletal muscle disorder and is one of the main causes of death due to anaesthesia. The reported incidence of MH varies from 1 in 12,000 in children to 1 in 40,000 in adults. MH is triggered in susceptible people by all commonly used inhalational anaesthetics; it is characterized by a profoundly accelerated muscle metabolism, contractures, hyperthermia and tachycardia. Susceptibility to MH (MHS) is predicted by contracture tests on muscle tissue obtained by biopsy. An almost identical disorder known as porcine MH exists in pigs. The genetics of the porcine syndrome have been extensively studied; the locus controlling expression of porcine MH is genetically linked to the glucose phosphate isomerase locus (GPI). In man, GPI has been mapped to the q12-13.2 region of chromosome 19 (refs 10-12). We have now investigated genetic linkage in several extended Irish pedigrees in which MHS is segregating as an autosomal dominant trait. Here we show linkage between MHS and DNA markers from the GPI region of human chromosome 19 with a maximum log likelihood ratio (lod score) of 5.65 at the CYP2A locus. These results indicate that human and porcine MH are most probably due to mutations in homologous genes, and also provide a potentially accurate and noninvasive method of diagnosis for MHS.