Integrating diverse scientific and practitioner knowledge in ecological risk analysis: a case study of biodiversity risk assessment in South Africa.

Ecological risk analysis (ERA) is a structured evaluation of threats to species, natural communities, and ecosystem processes from pollutants and toxicants and more complicated living stressors such as invasive species, genetically modified organisms, and biological control agents. Such analyses are typically conducted by a narrowly-focused group of scientific experts using technical information. We evaluate whether the inclusion of more diverse experts and practitioners in ERA improved the ecological knowledge base about South African biodiversity and the potential impacts of genetically modified (GM) crops. We conducted two participatory ERA workshops in South Africa, analyzing potential impacts of GM maize on biodiversity. The first workshop involved only four biological scientists, who were joined by 18 diverse scientists and practitioners in the second, and we compared the ERA process and results between the two using descriptive statistics and semi-structured interview responses. The addition of diverse experts and practitioners led to a more comprehensive understanding of biological composition of the agro-ecosystem and a more ecologically relevant set of hazards, but impeded hazard prioritization and the generation of precise risk assessment values. Results suggest that diverse participation can improve the scoping or problem formulation of the ERA, by generating an ecologically robust set of information on which to base the subsequent, more technical risk assessment. The participatory ERA process also increased the transparency of the ERA by exposing the logic and rationale for decisions made at each step.

Molecular systematics and evolution in an African cycad-weevil interaction: Amorphocerini (Coleoptera: Curculionidae: Molytinae) weevils on Encephalartos.

Weevils in the tribe Amorphocerini have been implicated in pollination of Encephalartos species in southern Africa. The services they render these plants and the unique attributes of the cycad-weevil interaction make them important from both conservation and evolutionary standpoints. Oberprieler [Oberprieler, R.G., 1996. Systematics and evolution of the tribe Amorphocerini, with a review of the cycad weevils of the world. Ph.D. dissertation, University of the Free State, Bloemfontein, South Africa], using morphological characters, proposed a tentative hypothesis of relationships among the Amorphocerini which is tested here using DNA sequence data. Sequences from one mitochondrial and three nuclear genes were used to infer phylogenetic relationships, levels of sequence divergence, evolution of host associations, and patterns of speciation in this tribe. The results are reasonably consistent with the morphological hypothesis of relationships and species concepts, though important differences are observed, particularly in relationships among a Porthetes hispidus Boheman species group, which is indicated to have experienced recent divergences. In general, low levels of sequence divergence among species within two of the three genera indicate a recent radiation of this tribe onto African cycads, thus while cycad-insect interactions have often been considered ancient this may not be the case for some extant interactions. A complex pattern of host shifts onto both closely related and more distantly related hosts is suggested.

Air embolism during tunneled central catheter placement performed without general anesthesia in children: a potentially serious complication.

Central venous catheters have had an increasingly important role in a variety of patient care situations, including long-term antibiotic therapy, chemotherapy, and nutritional support. The recent past has seen a gradual transition from placement of vascular access catheters by surgeons to placement by interventional radiologists. The interventional radiology service places a majority of the vascular access devices at our children's hospital, including peripherally inserted central catheters, tunneled central venous catheters, temporary and permanent hemodialysis catheters, and subcutaneous ports. Most procedures performed by our interventional radiology service in children can be successfully completed with use of intravenous (i.v.) sedation, and a few require general anesthesia (GA). Key advantages of GA over i.v. sedation include the ability to have positive pressure ventilation (PPV) or controlled apnea during the procedure. We report our experience of venous air embolism in three small children during placement of tunneled central venous catheters when GA was not used.

Long-term outcome of patients with intraspinal neuroblastoma.

BACKGROUND: Chemotherapy, radiotherapy, and surgical decompression with laminectomy are effective therapeutic options in the treatment of cord compression from neuroblastoma (NB). We report the long-term outcome of patients with intraspinal NB treated with or without laminectomy at two large pediatric oncology centers. PROCEDURE: We reviewed the medical records and radiographs of 26 children with intraspinal NB treated at Children's Memorial Hospital in Chicago, Illinois, between 1985 and 1994 or at St. Jude Children's Research Hospital in Memphis, Tennessee, between 1967 and 1992. RESULTS: Twenty-four of the 26 patients are alive and disease-free (follow-up of 2-29 years; median, 10 years 2 months). Fifteen of the 23 patients with neurologic impairment underwent initial laminectomy. Nine of these 15 patients recovered neurologic function, including 3 patients who presented with paraplegia. Eleven of the 15 patients who underwent laminectomy have developed mild to severe spinal deformities. Eight patients with neurologic symptoms consequent to cord compression were treated with initial chemotherapy and/or surgery, but did not undergo laminectomy. Three patients with mild to moderate deficits recovered neurologic function. Four of 11 patients with intraspinal NB who did not undergo laminectomy have mild to severe scoliosis. CONCLUSIONS: A low incidence of neurologic recovery was seen in patients with long-standing severe cord compression regardless of treatment modality. For patients with partial neurologic deficits, recovery was seen in most patients following chemotherapy or surgical decompression with laminectomy. A higher incidence of spinal deformities was seen in the patients treated with initial laminectomy.

Aspiration after administration of oral contrast material in children undergoing abdominal CT for trauma.

OBJECTIVE: The practice of routinely administering oral contrast material to children undergoing abdominal CT for blunt trauma is controversial, primarily because of the increased risk of aspiration. The purpose of this study was to determine how often aspiration occurs in this population of children. MATERIALS AND METHODS: We retrospectively studied 50 children who underwent abdominal CT scans after blunt trauma. All children received diluted 3% water-soluble oral contrast material. The medical record of each child was reviewed for evidence of aspiration pneumonia as many as 48 hr after the CT. In each patient, sections of the CT scan through the lung bases were examined for opacities. When lung opacities were identified, they were classified as atelectasis, confusion, laceration, or nonspecific. We made attenuation measurements of lung opacities larger than 1 cm, and each measurement was compared with the attenuation measurement of contrast material in that patient's stomach. Student's two-tailed t test was used to compare the two measurements. RESULTS: Four patients were febrile after the CT scan, but in none was aspiration pneumonia suspected to be the cause. The remaining 46 patients did not have any clinical evidence of aspiration. Twelve of the 50 patients had pulmonary opacities revealed by CT that were sufficiently large that attenuation measurements could be obtained. The opacity in one of these patients was classified as nonspecific, and the attenuation was as high as that of contrast material in the stomach. CONCLUSION: No clinically symptomatic episodes of aspiration pneumonia were found in 50 pediatric patients with blunt trauma who were given oral contrast material for abdominal CT. Although one of the children had CT findings that suggested clinically silent aspiration of oral contrast material, no evidence was found that administration of oral contrast material was harmful.

Efficacy of ketamine hydrochloride sedation in children for interventional radiologic procedures.

OBJECTIVE: The purpose of this study was to evaluate the efficacy of ketamine hydrochloride sedation in children younger than 11 years old who underwent short interventional radiologic procedures. SUBJECTS AND METHODS: Two hundred eleven children, 3 days to 10 years old, were given Ketalar (ketamine hydrochloride; Parke-Davis, Morris Plains, NJ), either 2 mg/kg i.v. (114 patients) or 3 mg/kg intramuscularly (i.m.) (97 patients). Atropine sulfate (Fujisawa USA, Deerfield, IL) (0.01 mg/kg i.v. or 0.02 mg/kg i.m.) was added in all patients to control secretions. Patients were monitored with continuous pulse oximetry and with automatic blood pressure cuffs. Respiratory rate and heart rate were recorded every 5 min. Adequacy of sedation was graded by the radiologist. Induction time, procedure time, recovery time, and adverse effects were recorded. RESULTS: Sedation was considered excellent and the procedures were completed in 191 patients (91%). The sedation was considered light but the procedures were completed in the remaining 20 patients (9%). No sedation failures were observed. Average induction time was 45 sec for the i.v. procedure and 4 min for the i.m. procedure. Average recovery time was 18 min for the i.v. procedure and 25 min for the i.m. procedure. Average procedure time for both methods was 25 min. Hemoglobin saturation remained at or greater than 95% in 200 patients (94%). Transient desaturation below 95% occurred in 11 patients (5%). The airway was manipulated to improve ventilation (head, neck, and jaw lifts) and supplemental oxygen was given via nasal cannula or mask. The episodes lasted only a few seconds and oxygen saturation promptly returned to a level greater than 95%. A 7-week-old male infant who had been born prematurely at 32 weeks' gestation experienced apnea. Ventilation was assisted for several breaths and the patient promptly recovered. We observed only minor cardiovascular changes in all patients. CONCLUSION: Ketamine hydrochloride provides excellent sedation and analgesia in young children. The short induction time, rapid recovery, and minimal respiratory depression are features that make this sedative ideal for interventional radiology.

Symptomatic hemangiomas and venous malformations in infants, children, and young adults: treatment with percutaneous injection of sodium tetradecyl sulfate.

OBJECTIVE: The purpose of this study was to evaluate the efficacy and safety of percutaneous sclerosis therapy using sodium tetradecyl sulfate for treatment of symptomatic hemangiomas and venous malformations in infants, children, and young adults. MATERIALS AND METHODS: Fifty-two sclerosis procedures were performed in 21 patients who were 13 months to 24 years old. Six of these patients had hemangiomas, and the remaining 15 patients had venous malformations. Sodium tetradecyl sulfate was injected solely percutaneously in 49 procedures, by both percutaneous and arterial routes in two procedures, and intraarterially only in one procedure. Thirteen patients had sclerosis therapy alone, and eight patients had sclerosis therapy followed by surgery within 48 hr. RESULTS: Sclerosis therapy alone or sclerosis therapy followed by surgery was judged beneficial in 18 (86%) of 21 patients, including five of the six patients who had hemangiomas and 13 of the 15 patients who had venous malformations. Two patients had an equivocal response to the therapy, and one patient had no apparent benefit. Three of the 21 patients had minor complications (skin ulcers) but no long-term sequelae. CONCLUSION: Percutaneous injection of sodium tetradecyl sulfate, either alone or before surgery, is a safe and effective method of managing symptomatic hemangiomas and venous malformations.

Imaging of developmental dysplasia of the hip.

Careful clinical examination remains the primary and most important way of diagnosing developmental dysplasia of the hip (DDH) in newborn infants. Repeated examinations during the first year are important to diagnose DDH subsequent to the newborn period. Sonography can detect cases of clinically silent DDH. Targeting high-risk infants for supplemental ultrasound screening at 4 to 6 weeks of age increases diagnosis of DDH and at significantly less expense than widespread screening. When sonography is not available, a pelvis radiograph at 3 months should be obtained in high-risk infants. Sonography also is used to monitor hip position and acetabular development in children undergoing harness treatment. Computed tomography and magnetic resonance imaging are reserved for children with more severe dysplasia, often as preoperative studies to help orthopedic surgeons to select the appropriate procedure.

Immediate effects of written material on attitudes toward homosexuality.

This study examined whether attitudes toward homosexuals were affected by educational material containing information about the biological determinants of sexual orientation. This study utilized a normed two-alternative inventory on which participants were asked to rate matched items on a 5-point scale. In the first session participants completed one version involving interactions with homosexual individuals. One week later, participants, randomly assigned to one of three groups, filled out the matched alternative form after reading a summary that presented either a biological or environmental basis for homosexuality or an unrelated article. Analysis confirmed previous research that the 40 men had more negative attitudes toward homosexuals than the 40 women but that different types of explanations for homosexuality had no over-all influence on attitudes. More importantly, an item analysis extended our previous understanding of sex differences in that physical proximity to the homosexual individual was the strongest factor associated with attitude change.

Peripherally inserted central venous catheters: US-guided vascular access in pediatric patients.

Ultrasound (US)-guided peripheral venipuncture was performed for peripheral insertion of 222 central venous catheters over a 12-month period. Initial placement was successful in 218 patients but unsuccessful in eight; placement was successful in four the next day (success rate, 98%; complication rate, 5%). Catheters were in place from 3 days to 6 months (mean, 36 days). US guidance allowed successful venipuncture for placement of central venous catheters in children.

MR imaging of hip disorders.

Magnetic resonance (MR) imaging has been applied to the study of a variety of hip disorders, principally the evaluation of avascular necrosis. The authors reviewed their experience with MR imaging of a variety of pediatric and adult hip diseases. Attention to the details of the imaging technique is essential for maximizing the diagnostic potential of MR imaging in the work-up of hip disease. Specific protocols that incorporate surface coil imaging, oblique imaging planes, and alternative pulse sequences are the foundation of successful hip studies. Gradient-echo imaging is essential for evaluating cartilaginous disorders, particularly in pediatric patients. For patients to benefit from the diagnostic capabilities of MR imaging, an appreciation of the unique information it provides must be communicated to referring physicians. In addition, an awareness of the atypical and unique MR appearances of certain hip disorders is necessary for accurate interpretation.

Anterior mediastinal lesions: transsternal biopsy with CT guidance. Work in progress.

PURPOSE: To assess the technique, results, and patient tolerance of transsternal biopsy of anterior mediastinal lesions under computed tomographic (CT) guidance. MATERIALS AND METHODS: Seven patients (four women and three men) with anterior mediastinal lesions underwent eight transsternal biopsies. Patients were included in the study if there was a risk of injury to internal mammary vessels or a danger of tranversing the lung by the biopsy needle. Patients were specifically questioned about the pain caused by the transsternal needle. A pain scale was not used. Conscious sedation and local anesthesia requirements provided gross evaluation of the patients' tolerance to the procedure. CT scans were used to guide and confirm optimal alignment of the transsternal needle with the lesion. RESULTS: Patients experienced minimal discomfort when the sternum was traversed. No instances of pneumothorax, postprocedural pain, or infection were encountered. In six of the seven patients, biopsy specimens were diagnostic. CONCLUSION: The transsternal approach for biopsy of anterior mediastinal lesions appears safe and is well tolerated.

CT of the azygoesophageal recess in infants and children.

The contour of the azygoesophageal recess (AER) as seen with computed tomography (CT) is an important indicator of mediastinal disorders. Radiologists must recognize, however, that the AER contour varies with patient age. The configuration of the AER is dextroconvex in children younger than 6 years, nonconcave (ie, equally divided between convex and straight) in children aged 6-12 years, and concave (or adult-like) in adolescents and young adults (aged 12-20 years). The cause of this variation is not certain; however, chest wall configuration does not seem to be an important factor. Although a convex AER is normal and common in pediatric patients, this normal appearance must be distinguished from that of mediastinal abnormalities (eg, foregut malformation cysts, vascular anomalies, lymphadenopathy), which can also produce obvious or subtle convexity of the AER. An appreciation for the age-related variation in AER configuration helps in the interpretation of CT scans. Criteria such as attenuation, morphologic characteristics, cephalocaudal extent, and multicompartmental involvement may be helpful in the differential diagnosis, but, generally, mediastinal abnormalities that alter the AER are nonspecific in appearance.

Rectal manometry, computed tomography, and functional results of anal atresia surgery.

Children with anal atresia often have compromised function. This is especially common with the anatomic "high lesion." Twenty-five patients have been studied using clinical evaluation, computed tomography (CT), and manometry to make an objective evaluation. The patients were an average of 9.6 years old; the male-to-female ratio was 3:2. Thirty-three percent had acceptable bowel function as defined by a continence score of 1 or 2. Only two (11%) had an abnormal sacrum. The mean rectal pressure was 20 cm H2O and 5 patients (23%) had a normal rectal relaxation reflex. Thirty percent had CT scans that demonstrated an intact external sphincter and puborectalis. In comparing the objective criteria and clinical results no technique could predict continence. CT demonstrated no significant group (P = .046 to .659) and manometry demonstrated no significant group (P = .082 to .752). We found no objective criteria that could evaluate the patient's clinical result or dictate therapy.

Malrotation of bowel: variable patterns with different surgical considerations.

The records of 53 patients with varied roentgenographic patterns of malrotation were reviewed. The patterns were categorized as A-Infantile (Al), A-Adult (Aa), B, C, and D. The differences in form were obvious and each differed clinically, radiographically, and surgically. The differences allowed the development of prognostic insights simply based on the presence and/or position of the ligament of Treitz and the cecum as shown by barium gastrointestinal examination. The literature was reviewed to find supportive or contradictory case material or other data that complemented or devalued the developed system for determining prognosis of patients with varied bowel patterns. The developed prognostic scheme seems to satisfy the requirements of reliability.