Hands-On Ultrasound Training for Radiology Residents: The Impact of an Ultrasound Scanning Curriculum

RATIONALE AND OBJECTIVES

Radiologists are responsible for interpreting ultrasound (US) images accurately, troubleshooting, aiding sonographers, and advancing technology and research. Despite this, most radiology residents do not feel confident performing US independently. The purpose of this study is to evaluate the impact of an abdominal US scanning rotation and digital curriculum on radiology residents' confidence and skills in performing US.

MATERIALS AND METHODS

All residents who were rotating in pediatric US at our institution for the first time were included (PGY 3-5). Those who agreed to participate were recruited sequentially from July 2018 to 2021 into (A) control and (B) intervention. B had a 1-week US scanning rotation and US digital course. Both groups completed a pre-and post-confidence self-assessment. Pre-and post-skills were objectively assessed by an expert technologist while participants scanned a volunteer. At completion, B completed an evaluation of the tutorial. Descriptive statistics summarized the demographics and closed questions. Pre-and post-test results were compared using paired-T tests, and effect size (ES) with Cohen's d. Open-ended questions were thematically analyzed.

RESULTS

PGY-3 and 4 residents participated, and were enrolled in A (N = 39) and B (N = 30). Scanning confidence significantly improved in both groups, with a greater ES in B (p < 0.01). Scanning skills significantly improved in B (p < 0.01) but not A. Eighty per cent of questionnaire responders used the integrative US tutorial and found it helpful. Free text responses were grouped into themes: 1) Technical issues, 2) Didn't complete course, 3) Didn't understand project, 4) Course was detailed and thorough.

CONCLUSIONS

Our scanning curriculum improved residents' confidence and skills in pediatric US and may encourage consistency in training, thus promoting stewardship of high-quality US.

Genomic profiling informs diagnoses and treatment in vascular anomalies

Vascular anomalies are malformations or tumors of the blood or lymphatic vasculature and can be life-threatening. Although molecularly targeted therapies can be life-saving, identification of the molecular etiology is often impeded by lack of accessibility to affected tissue samples, mosaicism or insufficient sequencing depth. In a cohort of 356 participants with vascular anomalies, including 104 with primary complex lymphatic anomalies (pCLAs), DNA from CD31+ cells isolated from lymphatic fluid or cell-free DNA from lymphatic fluid or plasma underwent ultra-deep sequencing thereby uncovering pathogenic somatic variants down to a variant allele fraction of 0.15%. A molecular diagnosis, including previously undescribed genetic causes, was obtained in 41% of participants with pCLAs and 72% of participants with other vascular malformations, leading to a new medical therapy for 63% (43/69) of participants and resulting in improvement in 63% (35/55) of participants on therapy. Taken together, these data support the development of liquid biopsy-based diagnostic techniques to identify previously undescribed genotype-phenotype associations and guide medical therapy in individuals with vascular anomalies.

Imaging of pediatric extragonadal pelvic soft tissue tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

The most common pediatric extragonadal pelvic cancers include germ cell tumors, sacrococcygeal teratomas, and rhabdomyosarcomas (arising from the urinary bladder, prostate, paratesticular tissues, vagina, uterus, and perineum). This paper describes the radiological and nuclear medicine features of these entities and provides consensus-based recommendations for the assessment at diagnosis, during, and after treatment.

Elevating Radiology Education Research Through a Dedicated Research Fellowship: Adding Professional Identity as Essential for Success

RATIONALE AND OBJECTIVES

Education research has been undervalued in radiology, with few radiology journals having dedicated space for such research and barriers to production including dedicated time, resources, grant funding, and mentorship. As radiologists, we have an opportunity to study education in our unique learning environments and create more effective ways to teach that are grounded in established education theory, solid assessment methodologies, and a focus on merit as well as worth.

MATERIALS AND METHODS

The growth of education research in our field requires a two-pronged approach; We must cultivate leaders in education research from within our specialty, and continue to submit high quality work to radiology journals to increase exposure of the reviewers and readership to education methodologies.

RESULTS

We have created the first radiology education research fellowship to this end. This manuscript details the fellowship creation process, the first education research fellow experience, and in-depth analysis of the inaugural year via a qualitative program review.

CONCLUSION

We were successful in supporting an inaugural fellow in attaining the knowledge and skills to become a productive education researcher. Beyond this, the fellowship experience was a catalyst in developing her unique professional identity as an education master which will further raise the status of education research in pediatric radiology.

First records of Gulcamptus huronensis Reid, 1996 (Copepoda, Harpacticoida, Canthocamptidae) from Lake Superior, with morphological notes on the male

Gulcamptus huronensis Reid, 1996 is a seldom-reported harpacticoid copepod known only from two female specimens, one collected from Lake Huron, Michigan, USA, the other from Nunatak Creek, Alaska, USA. Herein, we report a new distributional record for G. huronensis from the meiobenthos of Lake Superior, Michigan and Wisconsin, USA. A total of 12 specimens were collected from four localities across Lake Superior in August, 2018. Additionally, we provide information on the habitats where specimens of G. huronensis were recovered and morphological notes on the previously undescribed male of the species.

Job-Readiness After Pediatric Neuroradiology Training: Defining Trainee Needs

RATIONALE AND OBJECTIVES

To describe and analyze the pediatric neuroradiology implicit curriculum for general-pediatric and neuro-pediatric radiology fellowship training in order to define specific trainee needs and inform an explicit pediatric neuroradiology curriculum.

MATERIALS AND METHODS

A focus group of pediatric radiologists, pediatric neuroradiologists and fellows was conducted to create a needs assessment questionnaire that focused on training experience, current job, and a list of essential competency items. The questionnaire was distributed to 175 members of the Society for Pediatric Radiology. Data were derived from categorical and continuous survey variables. Using an inductive approach, we analyzed and systematically inspected the data to derive themes regarding trainee needs and how they might inform an explicit curriculum.

RESULTS

Fifty-seven pediatric radiologists (response rate of 33%) responded to the survey. Sixty-three percent of respondents were fellowship trained in general pediatric radiology, 21% in pediatric neuroradiology, and 16% in both. In their current jobs, 75% of respondents were responsible for interpreting some pediatric neuroradiology. 50% or greater reported limited or no fellowship instruction in five areas of imaging interpretation: fetal neuroimaging; ear and/or nose and/or throat imaging; head and neck imaging; neuroembryology; neuro-spectroscopy and four areas of technical skills and/or image quality: reducing imaging time; choice of contrast agents; sedation; understanding clinical management pathways.

CONCLUSION

Trainees endorse inadequate training in certain aspects of imaging interpretation and technical skills which are known to remain a significant and vital aspect of pediatric neuroradiology practice, revealing an opportunity to emphasize these aspects in an explicit curriculum and dedicate educational resources towards this cause.

Preserving the value of legacy film-based teaching files in pediatric radiology

Senior pediatric radiologists who have spent a major portion of their careers interpreting conventional film-screen radiographic studies have collected a wealth of hard-copy teaching material that is at risk of becoming obsolete. The teaching value and usefulness of analog film teaching files can be preserved using available hardware and standard software. The final product can be made available in a high-quality digital format to students, trainees and faculty without complicated search-and-retrieval methodology. This paper describes a relatively simple and low-cost procedure to preserve and use this source of wisdom and experience. It also emphasizes the role that such a resource can play as part of a comprehensive educational program.

Diagnostic performance and role of the contrast enema for low intestinal obstruction in neonates

PURPOSE

We aim to evaluate the diagnostic performance and relationship between clinical characteristics, imaging findings, and final diagnosis for the neonatal contrast enema (CE).

METHODS

Retrospective 10-year review of all neonatal CEs including imaging findings, clinical information, indication, and final diagnosis from discharge summaries, surgical reports, and pathology (reference standard). Two blinded pediatric radiologists reinterpreted 366 CEs for obstruction, microcolon, rectosigmoid index (RSI), serrations, meconium, ileal cut-off, transition zone, diagnosis, and level of confidence. CE diagnostic performance was calculated versus reference standard.

RESULTS

Diagnoses included Hirschsprung disease (HD) (15.8%), small left colon syndrome (14.8%), small intestinal atresia/colonic atresia (SIA/CA) (12.6%), meconium ileus (MI) (4.4%), and normal (48.9%). CE had a moderate specificity (87.7%) and low sensitivity (65.5%) for HD; abnormal RSI and serrations showed high specificities (90.3%, 97.4%) but low sensitivities (46.6%, 17.2%). CE showed high specificity (97.4%) and low sensitivity (56.3%) for MI blinded to cystic fibrosis status. Microcolon was specific (96.6%) but not sensitive (68.8%) for MI. CE showed highest PPV (73.1%) (specificity 95.6%, sensitivity 82.6%) for SIA/CA. Microcolon with an abrupt cut-off was specific (99.1%) but not sensitive (41.3%) for atresias.

CONCLUSION

Neonatal CE demonstrates high specificities and low to moderate sensitivities across all diagnoses, with lowest performance in HD.

CLINICAL TRIAL REGISTRATION

None.

Radiation in Pediatric Imaging: A Primer for Pediatricians

Medical imaging in children makes up a considerable percentage of all imaging procedures performed in the United States. Although in recent years there has been a 15% to 20% reduction in the exposure to ionizing radiation from medical imaging in the US population, the total number of computed tomography (CT) scans has increased from 2006 to 2016, and about 85% of all medical ionizing radiation in children is due to CT. [Pediatr Ann. 2020;49(9):e370-e373.].

Whole-body magnetic resonance imaging of pediatric cancer predisposition syndromes: special considerations, challenges and perspective

Cancer predisposition syndromes increase the incidence of tumors during childhood and are associated with significant morbidity and mortality. Imaging is paramount for ensuring early detection of neoplasms, impacting therapeutic interventions and potentially improving outcome. While conventional imaging techniques involve considerable exposure to ionizing radiation, whole-body MRI is a radiation-free modality that allows continuous imaging of the entire body and has increasingly gained relevance in the surveillance, diagnosis, staging and monitoring of pediatric patients with cancer predisposition syndromes. Nevertheless, widespread implementation of whole-body MRI faces several challenges as a screening tool. Some of these challenges include developing clinical indications, variability in protocol specifications, image interpretation as well as coding and billing practices. These factors impact disease management, patient and family experience and research collaborations. In this discussion we review the aforementioned special considerations and the potential direction that might help overcome these challenges and promote more widespread use of whole-body MRI in children with cancer predisposition syndromes.

Progressive pseudorheumatoid dysplasia: a report of three cases and a review of radiographic and magnetic resonance imaging findings

Progressive pseudorheumatoid dysplasia (PPD) is a rare disorder of postnatal skeletal and cartilage development that often presents with similar clinical findings to juvenile idiopathic arthritis. Patients with PPD display findings of progressive cartilage loss and secondary osteoarthritis over serial imaging studies and have an absence of elevation of inflammatory markers. Awareness of the imaging features of PPD on radiographs and magnetic resonance imaging (MRI) may be important for early diagnosis and surveillance of the disease.

Designing and testing an educational innovation

Technology provides an opportunity to develop innovations to improve the way we teach. Developing educational innovations must be approached in a methodical and thorough manner to identify the educational gap and validate the innovation's success in filling the gap. A successful educational innovation requires a stepwise approach that includes needs assessment, design of intervention, testing and analysis, evaluation of intervention, and determination of learning retention.

MRI of the bowel - beyond inflammatory bowel disease

MR enterography is traditionally used to evaluate inflammatory bowel disease (IBD) both at initial presentation and at follow-up. MR enterography can also be used to evaluate non-IBD conditions such as polyps or other masses of the gastrointestinal tract. In this article, we emphasize how to recognize bowel conditions beyond IBD on conventional abdominal MRI without a specific enterographic technique. In this overview we discuss common and uncommon pediatric bowel conditions beyond IBD seen on MRI including infectious and inflammatory conditions, congenital diseases and tumor and tumor-like conditions. Radiologists should become familiar with the salient imaging features of these bowel conditions to help guide management.

Anonymity and Electronics: Adapting Preparation for Radiology Resident Examination

RATIONALE AND OBJECTIVES

Diagnostic radiology resident assessment has evolved from a traditional oral examination to computerized testing. Teaching faculty struggle to reconcile the differences between traditional teaching methods and residents' new preferences for computerized testing models generated by new examination styles. We aim to summarize the collective experiences of senior residents at three different teaching hospitals who participated in case review sessions using a computer-based, interactive, anonymous teaching tool, rather than the Socratic method.

MATERIALS AND METHODS

Feedback was collected from radiology residents following participation in a senior resident case review session using Nearpod, which allows residents to anonymously respond to the teaching material.

RESULTS

Subjective resident feedback was uniformly enthusiastic. Ninety percent of residents favor a case-based board review incorporating multiple-choice questions, and 94% favor an anonymous response system.

CONCLUSIONS

Nearpod allows for inclusion of multiple-choice questions while also providing direct feedback to the teaching faculty, helping to direct the instruction and clarify residents' gaps in knowledge before the Core Examination.

Learning, technology and intellectual property: a survey of the philosophies and preferences of our trainees and peers

BACKGROUND

Increasing workloads threaten the quality of teaching in academic radiology practices. There is a wealth of unfiltered educational resources for radiology on the internet. As a digital native, today's radiology trainee may have differing opinions from teachers about learning and intellectual property.

OBJECTIVE

To identify the preferences and philosophies regarding learning, technology and intellectual property toward the future development of an innovative radiology curriculum.

MATERIALS AND METHODS

An electronic survey with 22 questions was sent to 2,010 members of the Society for Pediatric Radiology and 100 radiology trainees.

RESULTS

Three hundred sixty-one of the 2,110 surveys were returned. All questions were completed in 342 surveys. Fifty-three respondents were trainees (residents and fellows) and 289 respondents were radiologists (teachers). Time needed for a single learning activity in both groups is <30 min, but teachers spend less time (P=0.007). The preferred learning environments were point-of-care and outside work hours for both groups. Ideal lecture durations were 31-45 min for trainees and 21-30 min for teachers (P=0.001). Adoption of new technology showed late majority and laggard trends for both groups (P=0.296). Interest in gadgets was greater in trainees (17%) than teachers (2%) (P<0.001). Interest in lecture recording was greater in trainees (84%) than teachers (61%) (P=0.008). More trainees (61%) than teachers (42%) would not charge money for educational materials (P=0.028); 27% versus 13%, respectively, disagreed with dissemination of those materials beyond the institution (P=0.013).

CONCLUSION

While millennial trainees are adult learners with a stronger comfort with technology, learning styles of trainees and teachers are more similar than was previously believed. Trainees and teachers hold conflicting philosophies about intellectual property. Results herein speak favorably for revising our teaching portfolio to include practical learning materials of short duration available at point-of-care.

How and how well do pediatric radiology fellows learn ultrasound skills? A national survey

BACKGROUND

Ultrasound (US) comprises a significant portion of pediatric imaging. Technical as well as interpretive skills in US imaging are consequently fundamental in training pediatric radiologists. Unfortunately, formalized technical education regarding US imaging in pediatric fellowships has lagged.

OBJECTIVE

We surveyed pediatric fellows and program directors regarding US scanning education to improve this experience moving forward.

MATERIALS AND METHODS

We conducted an online survey from February 2011 to March 2011 of all United States pediatric radiology body imaging fellows and fellowship program directors. Questions posed to fellows assessed their educational US experiences during their residencies and fellowships. Directors were asked to evaluate US educational opportunities in their programs.

RESULTS

Among the respondents, 43.9% of fellows undertook on-call US scanning without a sonographer during residency, 23.3% during fellowship; 41.8% of fellows and 58.6% of program directors reported that their fellowship had a dedicated curriculum to facilitate independent US scanning. Both fellows and program directors cited the volume of cases requiring immediate dictation as an obstacle to scanning. Fewer program directors than fellows identified lack of sufficient staffing as an obstacle, but more identified fellow disinterest. Program directors and fellows alike rated independent US scanning as highly important to pediatric radiologists' future success.

CONCLUSION

Pediatric radiology fellowship directors and fellows agree that technical US skills are crucial to the practice of pediatric radiology. However, the groups identify different obstacles to training. As US instruction is developing in undergraduate medicine and subspecialists are acquiring point-of-care US skills, pediatric radiology education should address the obstacles to US training and formalize a curriculum at the fellowship level.

Intestinal obstruction secondary to infantile polyarteritis nodosa

Polyarteritis Nodosa (PAN) is a rare systemic necrotising vasculitis of medium and small-sized arteries. Patients typically present with systemic symptoms. Obstructive intestinal symptoms are described but usually resolve with treatment of the underlying vascular disease. We report a case of a one year old boy with multiple ischemic small bowel strictures secondary to infantile PAN, who was treated with resection of the affected segments by single port laparoscopy.

Altered specificity of lactococcal proteinase p(i) (lactocepin I) in humectant systems reflecting the water activity and salt content of cheddar cheese

By using various humectant systems, the specificity of hydrolysis of alpha(s1)-, beta-, and kappa-caseins by the cell envelope-associated proteinase (lactocepin; EC 3.4.21.96) with type P(1) specificity (i.e., lactocepin I) from Lactococcus lactis subsp. lactis BN1 was investigated at water activities (a(w)) and salt concentrations reflecting those in cheddar type cheese. In the presence of polyethylene glycol 20000 (PEG 20000)-NaCl (a(w) = 0.95), hydrolysis of beta-casein resulted in production of the peptides comprising residues 1 to 6 and 47 to 52, which are characteristic of type P(III) enzyme activity (lactocepin III) in buffer. The fragment comprising residues 1 through 166, inclusive (fragment 1-166), which is typical of lactocepin I activity in buffer systems, was not produced. Similarly, peptide 152-160 from kappa-casein, which is usually produced in aqueous buffers exclusively by lactocepin III, was a major product of lactocepin I. Most of the specificity differences obtained in the presence of PEG 20000-NaCl were also obtained in the presence of PEG 20000 alone (a(w) = 0.99). In addition, alpha(s1)-casein, which normally is resistant to lactocepin I activity, was rapidly hydrolyzed in the presence of PEG 20000 alone. Hydrolysis of casein in the presence of PEG 300-NaCl or glycerol-NaCl (both having an a(w) of 0.95) was generally as expected for lactocepin I activity except that beta-casein peptide 47-52 and kappa-casein fragment 1-160 were produced; both of these are normally formed by lactocepin III in buffer. The differences in lactocepin specificity obtained in the humectant systems can be attributed to a combination of a(w) and humectant hydrophobicity, both of which are parameters that are potentially relevant to the cheese-ripening environment.

Atypical, perhaps under-recognized? An unusual phenotype of Friedreich ataxia

Friedreich ataxia (FRDA) is typically characterized by slowly progressive ataxia, depressed tendon reflexes, dysarthria, pyramidal signs, and loss of position and vibration sense with onset before 25 years. While several atypical forms of FRDA are recognized, profound vision deficit is rare. We describe here a 41-year-old man with profound vision deficit and episodic complete blindness associated with marked optic atrophy, spastic paraparesis, and sensory neuropathy without ataxia whose diagnostic evaluation revealed compound heterozygosity for two frataxin mutations, a 994 GAA repeat intronic expansion and c.389G > T (p.G130V) missense mutation. This case emphasizes that FRDA should be considered for individuals with significant vision deficit with optic atrophy and sensory neuropathy, even in the absence of ataxia. This case also raises the additional, related concern that prior studies may underestimate the frequency and varieties of variant forms of FRDA.

The accuracy of chest radiographs in the detection of congenital heart disease and in the diagnosis of specific congenital cardiac lesions

BACKGROUND

Congenital heart disease (CHD) is a significant cause of morbidity and mortality in pediatric patients. Traditional teaching holds that specific types of CHD can be diagnosed on the chest radiograph (CXR) through pattern recognition.

OBJECTIVE

To determine the accuracy of radiologists in detecting CHD on the CXR.

MATERIALS AND METHODS

This study was a blinded retrospective review of chest radiographs from 281 patients (<12 years) by five pediatric radiologists from three institutions. Thirteen groups were evaluated that included 12 categories of CHD and a control group of patients without heart disease. Radiographs were assessed for heart size, heart and mediastinal shape and vascularity. Clinical information, angiography, echocardiograms and surgery were used as the gold standard for definitive diagnosis.

RESULTS

The average accuracy of the five readers in distinguishing normal from CHD patients was 78% (range of 72% to 82%). The overall measure of accuracy in distinguishing specific congenital cardiac lesions among 13 groups of patients was 71% (range of 63% to 79%).

CONCLUSION

CXR alone is not diagnostic of specific cardiac lesions, with a low accuracy of only 71%. We believe that less emphasis should be placed on the use of radiographs alone in diagnosing specific congenital cardiac lesions.

Neonates with hypoplastic left heart syndrome have ultrasound evidence of abnormal superior mesenteric artery perfusion before and after modified Norwood procedure

OBJECTIVE

To a) describe superior mesenteric artery resistive index, as an estimate of perfusion, before and after modified Norwood; and b) assess incidence of diastolic flow reversal in the superior mesenteric artery before and after modified Norwood.

DESIGN

Prospective observational trial.

SETTING

Children's hospital pediatric intensive care unit.

PATIENTS

Ten newborns with hypoplastic left heart syndrome.

INTERVENTIONS

Ultrasound documentation of superior mesenteric artery diastolic flow direction and measurement of superior mesenteric artery resistive index 24-48 hrs before and 24-48 hrs after modified Norwood.

MEASUREMENTS AND MAIN RESULTS

Seven males and three females were enrolled. There was no change between the superior mesenteric artery resistive index pre- vs. postoperatively-0.99 (95% confidence interval, 0.85, 1.12) vs. 1.07 (95% confidence interval, 1.0, 1.15) (p = .13). Incidence of retrograde diastolic blood flow in the superior mesenteric artery was not different pre- vs. postoperatively (70% vs. 50%, p = .41). No patients developed necrotizing enterocolitis and all survived to hospital discharge.

CONCLUSIONS

Ultrasound measurements in neonates with hypoplastic left heart syndrome suggest that superior mesenteric artery perfusion, as measured by resistive index, is impaired. Superior mesenteric artery diastolic flow reversal is common before and immediately after modified Norwood.

RADPED: an approach to teaching communication skills to radiology residents

BACKGROUND

The Accreditation Council for Graduate Medical Education mandates that radiology residency programs teach communication skills to residents.

OBJECTIVE

The purpose of this paper is to present a mnemonic, RADPED, that can be used to enhance communication in the radiology setting. It reminds the resident of the salient points to address during an imaging encounter with pediatric patients and their families for the purpose of enhancing communication.

MATERIALS AND METHODS

Recent history and research in medical communication are reviewed. Various communication guides used by primary care physicians, such as SEGUE, and the Kalamazoo consensus statement are discussed. This methodology was adapted into a format that could be used to teach communication skills to radiology residents in the context of an imaging encounter.

RESULTS

RADPED reminds the resident to establish rapport with the patient, ask questions as to why the patient and family are presenting for the study, discuss the exam, perform the procedure, use exam distractions, and discuss the results with the referring physician and family when appropriate.

SUMMARY

This simple memory aid promotes the key points necessary to optimize the radiology resident's encounter with pediatric patients and their families.

Complications of pediatric paranasal sinusitis

Acute paranasal sinus infection in children is often diagnosed clinically without the need for radiographic confirmation. Most cases have a favorable outcome following appropriate antibiotic therapy. A small percentage of cases where symptoms and signs are persistent or severe will require emergent imaging to rule out complications related to local spread of disease intraorbitally or intracranially. A strong index of suspicion is required in such cases, and cross-sectional imaging evaluation with CT and MRI should include axial and coronal images of the paranasal sinuses and, where appropriate, the orbits and brain (with attention to the cavernous sinus). There is no role for plain radiography in the evaluation of the complications of acute sinusitis in the pediatric patient.

Creating an international comprehensive web-based curriculum in pediatric radiology

OBJECTIVE

This article describes the creation of a standardized comprehensive resident curriculum in pediatric radiology that uses adult learning principles authored by international experts and addresses the six general competencies required by the Accreditation Council for Graduate Medical Education.

CONCLUSION

Web-based learning with an online curriculum has the potential to become an integral component of residency training. The use of radiology experts as authors allows compilation of an authoritative, comprehensive, and current body of knowledge that enhances the current teaching file approach to Web-based instruction in radiology. We describe the approach, design, and tools necessary for the construction of a complete Web-based curriculum in pediatric radiology that includes self-assessment through pre- and post-testing, text with interactive images, curriculum evaluation, and the ability to record trainee demographics.

Systemic arterial pneumatosis in a neonate with necrotizing enterocolitis

Ultrasound is exquisitely sensitive for the identification of portal vein pneumatosis, which in neonates is commonly caused by necrotizing enterocolitis. We describe the ultrasound finding of systemic arterial pneumatosis in a case of necrotizing enterocolitis associated with congenital heart disease. A combination of a patent ductus venosus and an extracardiac right-to-left shunt via the great vessels through a patent ductus arteriosus provided a pathway for the pneumatosis from the portal vein to the abdominal aorta.

Thoracic outlet syndrome in a child--transaxillary resection of anomalous first rib

Thoracic outlet syndrome (TOS) is extremely rare in children. Only several pediatric cases have been reported, and all presented with neurologic symptoms. The authors report on a 6-year-old boy with an asymptomatic left subclavian artery aneurysm caused by compression of the subclavian artery by an anomalous first rib with poststenotic aneurysmal dilatation. This was successfully managed by transaxillary resection of the anomalous rib. This represents the youngest reported case of TOS and the first description of a vascular manifestation of TOS in the pediatric population. Access to the costoscalene triangle utilizing a transaxillary approach was straightforward and afforded excellent exposure, even in a child.

Genital tract tumors in Proteus syndrome: report of a case of bilateral paraovarian endometrioid cystic tumors of borderline malignancy and review of the literature

Proteus syndrome is a rare, sporadic disorder that causes postnatal overgrowth of multiple tissues in a mosaic pattern. Characteristic manifestations include: overgrowth and hypertrophy of limbs and digits, connective tissue nevus, epidermal nevus and hyperostoses. Various benign and malignant tumors and hamartomas may complicate the clinical course of patients with the syndrome. Commonly encountered tumors include hemangiomas, lymphangiomas and lipomas. Tumors of the genital tract occur less often. Bilateral ovarian cystadenomas are regarded as having diagnostic value in Proteus syndrome when occurring within the first two decades of life. We describe a 3-year-old girl with Proteus syndrome who developed bilateral paraovarian villoglandular endometrioid cystadenomatous tumors of borderline malignancy (low malignant potential) of the broad ligament. Desmoplastic tumor implants, presumably noninvasive, were present in biopsies from the pelvic floor, cul-de-sac and omentum. This is the first recognized example of a cystic borderline epithelial tumor of the female genital tract and the first paraovarian tumor reported in a patient with Proteus syndrome. Previously reported tumors and cystic lesions involving the female genital tract and the male genital tract in patients with Proteus syndrome are reviewed. We suspect that specific testicular and paratesticular tumors may prove to have the same diagnostic value in Proteus syndrome as do bilateral cystic ovarian and paraovarian tumors.

Thoracic outlet syndrome with subclavian aneurysm in a very young child: the complementary value of MRA and 3D-CT in diagnosis

Thoracic outlet syndrome (TOS) is rare in childhood. In adults, TOS results in compression of the neurovascular bundle (branches of the brachial plexus and the subclavian artery), but more than 95% of cases present solely with neurologic compression. We present a case of TOS in a very young child and describe the rare finding of subclavian artery compression and post-stenotic aneurysm. The clinical features, imaging workup, and surgical findings are discussed. The combination of three-dimensional MR angiography and CT was of great value in diagnosis and surgical planning.

The barium enema in constipation: comparison with rectal manometry and biopsy to exclude Hirschsprung's disease after the neonatal period

BACKGROUND

The diagnosis of Hirschsprung's disease is usually made in neonates but often considered in older infants and children with constipation: these children may be referred for barium enema. Since it is widely accepted that a normal barium enema does not exclude Hirschsprung's disease, some children, after a normal enema, undergo more invasive procedures such as rectal manometry or biopsy. Our study asked how frequently a diagnosis of Hirschsprung's disease was made by biopsy or manometry in children who had normal barium enema.

MATERIALS AND METHODS

We reviewed the medical records and barium enemas of 54 patients older than 28 days with constipation or difficulty passing stool who had a barium enema followed by manometry and/or biopsy.

RESULTS

Forty-eight patients had normal enemas: 24 of those patients had biopsies, 16 had manometry, and 8 both manometry and biopsy. Only 1 had manometry suggestive of Hirschsprung's disease, confirmed by biopsy. Six patients had abnormal enemas. Five had biopsy and manometry compatible with Hirschsprung's disease; one had a normal biopsy and manometry study.

CONCLUSION

The barium enema is a good initial screening test for Hirschsprung's disease in severely constipated children since it correlates well with manometry and biopsy. The enema is particularly useful in centers without easy access to pediatric gastroenterology services, and a normal enema in this setting allows the continuation of medical therapy with further evaluation only if there is a lack of response. An abnormal enema, however, requires referral to a facility equipped to perform confirmatory manometry or biopsy.

A micromachined vibration isolation system for reducing the vibration sensitivity of surface transverse wave resonators

A micromachined system has been developed for reducing the vibration sensitivity of surface transverse wave (STW) resonators. The isolation system consists of a support platform for mounting the STW resonator, four support arms, and a support rim. The entire isolation system measures 8 mm by 9 mm by 0.4 mm without the resonator mounted on the platform. The system acts as a passive vibration isolation system, decreasing the magnitude of high frequency (>1.2 kHz) vibrations. Finite element analysis is used to analyze the acceleration sensitivity of the mounted resonator. The isolation system is then modeled as a damped mass-spring system and the transmissibility of vibration from the support rim to the support platform is calculated. Multiplying the acceleration sensitivity of the resonator by the transmissibility results in the expected system vibration sensitivity. The isolation systems are fabricated using two sided bulk etching of (110) oriented silicon wafers. STW resonators were mounted on the isolation systems, and the isolated units were mounted on commercial hybrid oscillator substrates. Vibration sensitivity measurements were taken for vibrations with frequencies ranging from 100 Hz to 5 kHz. The measured data show that the system performs as expected with a low frequency (<500 Hz) vibration sensitivity of 1.8x10(-8)/g and a high frequency roll off of 12 dB/octave.

Phase II trial of chloroquinoxaline sulfonamide (CQS) in patients with stage III and IV non-small-cell lung cancer

PURPOSE

Chloroquinoxaline sulfonamide (CQS) was one of the first agents identified by the human tumor colony-forming assay (HTCFA) as possessing antitumor activity in non-small-cell lung cancer (NSCLC). Prior phase I studies had suggested that plasma concentrations equivalent to those showing efficacy in the HTCFA could be reliably attained in humans. This phase II study assessed the antitumor activity of CQS while using an adaptive control pharmacokinetic modelling system to attain targeted plasma levels of this novel compound.

METHODS

A group of 20 patients with stage III or IV NSCLC received CQS as a 1-h weekly infusion at an initial dose of 2 g/m2. In all patients, 24-h plasma concentrations of CQS were measured. Patients with levels < 100 micrograms/ml had dose increases determined by their 24-h levels and pharmacokinetic parameters obtained from two prior phase I trials of this agent. These individuals had 24-h CQS levels repeated after their second weeks' treatment and doses were readjusted if the target concentration was not reached. Antitumor response assessment was made every 6 weeks.

RESULTS

Of the 20 patients, 18 attained the target plasma concentration, and 16 of these achieved this initially or with just one dose adjustment. No major objective antitumor responses were observed (major response rate 0%, 95% CI 0-17%). CQS was well tolerated with hypoglycemia being the most clinically significant toxicity.

CONCLUSIONS

When given on this schedule CQS is inactive in NSCLC despite the fact that the target concentration was achieved in 90% of patients. The ability of the HTCFA to identify active agents remains unproved.

3D construction from spiral CT scanning of pericardial calcification

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In vitro characterization of a novel series of platelet-derived growth factor receptor tyrosine kinase inhibitors

In this report, we describe the discovery and characterization of a novel biarylhydrazone series of platelet-derived growth factor (PDGF) receptor tyrosine kinase inhibitors typified by the prototype WIN 41662 (3-phenyl-N1-[1-(4-pytidyl)pyrimidine]hydrazone). WIN 41662 inhibited PDGF-stimulated autophosphorylation of PDGF receptors from human vascular smooth muscle cells (hVSMC) with an IC50 value of 60 nM. The inhibitor appeared to be competitive with respect to substrate (Mn(2+)-ATP), having a calculated Ki of 15 +/- 5 nM. WIN 41662 was approximately 500-fold more potent in inhibiting the PDGF receptor tyrosine kinase than the p56lck tyrosine kinase. It was inactive against other serine/threonine and tyrosine kinases tested. WIN 41662 produced concentration-dependent inhibition of PDGF-stimulated receptor autophosphorylation in intact hVSMC with an IC50 < 100 nM. Intracellular Ca2+ mobilization and cell proliferation were events that occurred in hVSMC subsequent to PDGF receptor activation. WIN 41662 inhibited PDGF-stimulated Ca2+ mobilization and cell proliferation ([3H]TdR incorporation) with IC50 values of 430 nM and 2.3 microM, respectively. These effects appeared to be specifically related to PDGF receptor tyrosine kinase inhibition since WIN 41662 was not cytotoxic (in vitro) and since WIN 72039, a close structural analog that does not inhibit PDGF receptor tyrosine kinase, also did not inhibit PDGF-stimulated receptor autophosphorylation, Ca2+ mobilization, or hVSMC proliferation. Thus, WIN 41662 is representative of a novel class of selective PDGF receptor tyrosine kinase inhibitors that inhibit PDGF-regulated secondary events in intact cells.

Involvement of enzyme-substrate charge interactions in the caseinolytic specificity of lactococcal cell envelope-associated proteinases

Three series of oligopeptides were synthesized to investigate the proposal that a major factor in determining the differences in specificity of the lactococcal cell surface-associated proteinases against caseins is the interactions between charged amino acids in the substrate and in the enzyme. The sequences of the oligopeptides were based on two regions of kappa-casein (residues 98 to 111 and 153 to 169) which show markedly different susceptibilities to PI- and PIII-type lactococcal proteinases. In each series, one oligopeptide had an identical sequence to that of the kappa-casein region, while in the others, one or more charged residues were substituted by an amino acid of opposite charge, i.e., His<-->Glu. Generally, substitution of His by Glu in the oligopeptides corresponding to residues 98 to 111 of kappa-casein resulted in reduced cleavage of susceptible bonds by the PI-type proteinase and increased cleavage of susceptible bonds by the PIII-type proteinase. In the case of the oligopeptide corresponding to residues 153 to 169 of kappa-casein, one major cleavage site was evident, and the bond was hydrolyzed by both types of proteinase (even though this sequence in kappa-casein itself is extremely resistant to the PI-type enzyme). Substitution of Glu by His in this oligopeptide, even in the P7 position, resulted in increased cleavage of the bond by the PI-type proteinase and reduced cleavage by the PIII-type proteinase. C-terminal truncation of this oligopeptide resulted in a 100-fold decrease in the rate of hydrolysis of the susceptible bond and a change in the pattern of cleavage.(ABSTRACT TRUNCATED AT 250 WORDS)

Specificity of hydrolysis of bovine kappa-casein by cell envelope-associated proteinases from Lactococcus lactis strains

The cell envelope-associated proteinases from Lactococcus lactis subsp. cremoris H2 (a PI-type proteinase-producing strain) and SK11 (a PIII-type proteinase-producing strain) both actively hydrolyze the kappa-casein component of bovine milk but with significant differences in the specificity of peptide bond hydrolysis. The peptide bonds Ala-23-Lys-24, Leu-32-Ser-33, Ala-71-Gln-72, Leu-79-Ser-80, Met-95-Ala-96, and Met-106-Ala-107 were cleaved by both proteinase types, although the relative rates of hydrolysis at some of these sites were quite different for the two proteinases. Small histidine-rich peptides were formed as early products of the action of the cell envelope-associated proteinases on kappa-casein, implicating this casein as a possible significant source of histidine, which is essential for starter growth. The major difference between the two proteinase types in their action on kappa-casein was in their ability to cleave bonds near the C-terminal end of the molecule. The bond Asn-160-Thr-161 and, to a lesser extent, the bond Glu-151-Val-152 were very rapidly cleaved by the PIII-type proteinase, whereas hydrolysis of these bonds by the PI-type proteinase was barely detectable (even after 24 h of digestion). Differential hydrolysis of kappa-casein at these sites by the two different proteinase types resulted in the formation of distinctive, high-M(r) products detectable by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.(ABSTRACT TRUNCATED AT 250 WORDS)

Stability and Specificity of the Cell Wall-Associated Proteinase from Lactococcus lactis subsp. cremoris H2 Released by Treatment with Lysozyme in the Presence of Calcium Ions

The cell wall-associated proteinase from Lactococcus lactis subsp. cremoris H2 (isolate number 4409) was released from the cells by treatment with lysozyme, even in the presence of 50 mM calcium chloride. Cell lysis during lysozyme treatment was minimal. The proteinase activity released by lysozyme treatment fractionated on ion-exchange chromatography as three main forms, the molecular masses of which were determined by gel exclusion chromatography and polyacrylamide gel electrophoresis. Two of the enzyme forms released, 137 and 145 kDa, were the same as those released by incubation of cells in calcium-free phosphate buffer. In the presence of calcium, lysozyme treatment also resulted in the release of a 180-kDa enzyme molecule. The total proteinase activity released by lysozyme treatment (in the presence or absence of calcium) was not only greater than that released by phosphate buffer but was also greater than that initially detectable on the surface of whole cells, suggesting an unmasking of enzyme on the cell surface. The presence of calcium during release treatment resulted in increased stability of the crude enzyme preparations. For the proteinase preparation released by using lysozyme with 50 mM CaCl 2 , the half-life of proteinase activity at 37°C was 39 h, compared with 0.22 h for the calcium-free phosphate buffer-released preparation. In all cases, maximum stability was observed at pH 5.5. Comparison of β-casein hydrolysis by the three forms of the enzyme showed that the products of short-term (5- to 30-min) digestions were very similar, although subtle differences were detected with the 180-kDa form.