Relationships of outdoor and indoor ultrafine particles at residences downwind of a major international border crossing in Buffalo, NY.

UNLABELLED: During winter 2006, indoor and outdoor ultrafine particle (UFP) size distribution measurements for particles with diameters from 5.6 to 165 nm were taken at five homes in a neighborhood directly adjacent to the Peace Bridge Complex (PBC), a major international border crossing connecting Buffalo, New York to Fort Erie, Ontario. Monitoring with 1-s time resolution was conducted for several hours at each home. Participants were instructed to keep all external windows and doors closed and to refrain from cooking, smoking, or other activity that may result in elevating the indoor UFP number concentration. Although the construction and age for the homes were similar, indoor-to-outdoor comparisons indicate that particle infiltration rates varied substantially. Overall, particle concentrations indoors were lower and less variable than particle concentrations outdoors, with average indoor-outdoor ratios ranging from 0.1 to 0.5 (mean 0.34) for particles between 5.6 and 165 nm in diameter. With no indoor sources, the average indoor-outdoor ratios were lowest (0.2) for 20-nm particles, higher (0.3) for particles <10 nm, and highest (0.5) for particles 70-165 nm. PRACTICAL IMPLICATIONS: This study provides insight into the penetration of UFP into homes and the resulting change in particle size distributions as particles move indoors near a major diesel traffic source. Although people spend most of their time in their homes, exposure estimates for epidemiological studies are generally determined using ambient concentrations. The findings of this study will contribute to improved size-resolved UFP exposure estimates for near roadway exposure assessments and epidemiological studies.

Detection of changes in alveolar macrophage iron status induced by select PM2.5-associated components using iron-response protein binding activity.

The extent of adverse health effects, including induction/exacerbation of infectious lung disease, arising from entrainment of equivalent amounts (or exposure to a fixed increment) of fine particulate matter (PM2.5) can vary from region to region or city to city in a region. To begin to explain how differing effects on host resistance might arise after exposure to PM2.5 from various sites, we hypothesized that select metals (e.g., V, Al, and Mn) in each PM2.5 caused changes in alveolar macrophage (AM) Fe status that, ultimately, would lead to altered antibacterial function. To test this, iron-response protein (IRP) binding activity in a rat AM cell line was assessed after exposure to Fe alone and in conjunction with V, Mn, and/or Al at ratios of V:Fe, Al:Fe, or Mn:Fe encountered in PM2.5 samples from New York City, Los Angeles, and Seattle. Results indicated that V and Al each significantly altered IRP activity, though effects were not consistently ratio-(i.e., dose-) dependent; Mn had little impact on activity. We conclude that the reductions in Fe status detected here via the IRP assay arose, in part, from effects on transferrin-mediated Fe3+ delivery to the AM. Ongoing studies using this assay are allowing us to better determine: (1) whether mass (and/or molar) relationships between Fe and V, Al, and/or Mn in any PM2.5 sample consistently govern the extent of change in AM Fe status; (2) how much any specified PM2.5 constituent (metal or nonmetal) contributes to the overall disruption of Fe status found induced by an intact parent sample; and (3) whether induced changes in binding activity are relatable to other changes expected to occur in the AM, that is, in IRP-dependent mRNA/levels of ferritin/transferrin receptor and Fe-dependent functions. These studies demonstrate that pollutant-induced effects on lung cell Fe status can be assessed in a reproducible manner using an assay that can be readily performed by investigators who might otherwise have no access to other very costly analytical equipment, such as graphite atomic absorption or x-ray fluorescence spectro(photo)meters.

Unusual penetrating orbit injury.

Penetrating head and face injuries can cause hemorrhages, neurological lesions, visual acuity loss, fractures and facial deformities. This report discusses an injury caused by a knife that penetrated the left orbit and reached the skull base without damaging any important structures. The knife was removed through the entrance wound and no complications were observed either during or after surgery.

Measurement of total lung deposition of inhaled ultrafine particles in healthy men and women.

Ultrafine particles (< 0.10 microm in diameter) are present in great number in polluted urban air, thus posing a potential health risk. In this study, the total deposition fraction (TDF) of ultrafine aerosols with a narrow size distribution (number median diameter NMD = 0.04-0.1 microm and geometric standard deviation sigma(g) = approximately 1.3) was measured in a group of young healthy adults (11 men and 11 women). TDF was obtained with 6 different breathing patterns: tidal volume (V(t)) of 500 ml at respiratory flow rates (Q) of 150 and 250 ml/s; V(t) = 750 ml at Q of 250 and 375 ml/s; and V(t) = 1 L at Q of 250 and 500 ml/s. Aerosols were monitored continuously by a modified condensation nuclei counter while subjects were inhaling them with prescribed breathing patterns. For a given breathing pattern, TDF increased as particle size decreased, regardless of the breathing pattern used. For example, with V(t) = 500 ml and Q = 250 ml/s, TDF (mean +/- SD) was 0.26 +/-.04, 0.30 +/-. 05, 0.35 +/-.05, and 0.44 +/-.07 for NMD = 0.10, 0.08, 0.06, and 0. 04 microm, respectively. For a given NMD, TDF increased with an increase in V(t) and a decrease in Q. TDF was greater for women than men at NMD = 0.04 microm within all breathing patterns used (p <.05), but the difference was smaller or negligible for larger sized particles. The results suggest that the TDF of ultrafine particles increases with a decrease of particle size and with breathing patterns of longer respiratory time, a pattern that is consistent with diffusion deposition of ultrafine particles. The results also suggest that there is a differential lung dose of ultrafine particles and thus there may be a differential health risk for men versus women.

Primary Gianturco stent placement for inferior vena cava abnormalities following liver transplantation.

PURPOSE: To determine the efficacy of primary Gianturco stent placement for patients with inferior vena caval (IVC) abnormalities following liver transplantation. MATERIALS AND METHODS: From August 1996 through March 1999, nine adult patients developed significant IVC abnormalities following liver transplantation. Patients were referred for vena cavography on the basis of abnormal clinical findings, laboratory values, liver biopsy results, Doppler findings, or a combination. Those patients demonstrating a significant caval or hepatic venous gradient were treated with primary Gianturco stent placement. Patients were followed clinically (nine patients), with duplex ultrasound (nine patients), vena cavography (four patients), and biopsy (seven patients). RESULTS: Original pressure gradients ranged from 3 to 14 mm Hg, with a mean of 9 mm Hg. Gradients were reduced to 3 mm Hg or less in all nine patients; presenting signs and symptoms either resolved or improved in eight of nine patients. The ninth patient required repeated transplantation 2 days later. A second patient died 433 days after stent placement of recurrent hepatitis C. Another initially improved following caval stent placement, but underwent repeated transplantation 7 days later due to hepatic necrosis from hepatic arterial thrombosis. Follow-up for the remaining six patients has averaged 491 days, with no clinical, venographic, or ultrasound evidence for recurrent caval stenosis. CONCLUSIONS: Intermediate term results suggest that primary Gianturco stent placement for IVC stenosis, compression, or torsion resulting after liver transplantation is safe and effective.

Resource requirements for interventional radiologic management of long-term ambulatory hemodialysis patients.

OBJECTIVE: The purpose of this study was to determine how many and what type of procedures a vascular and interventional radiology service should provide for patients at ambulatory-patient dialysis centers and to determine the necessary resource requirements. These data may provide a realistic starting point for those engaged in the planning and provision of contractual services to dialysis centers. MATERIALS AND METHODS: Patient records at three dialysis centers for a recent 3-year period were examined, and demographic and clinical data were recorded. Records were cross-correlated with records from the vascular and interventional radiology service that had contractually provided all dialysis-related procedures. These data generated a monthly procedure volume and case mix per 100 dialysis patients. Facility usage times for 121 dialysis-related procedures were obtained prospectively and used to calculate the expected resources needed to service the dialysis patients. RESULTS: The three centers provided 5795 hemodialysis-months to 386 patients. Of the 386 patients over the 36-month period, 101 died and 92 transferred from the centers. Three hundred and sixteen patients required 1580 interventional procedures. Monthly procedure volume per 100 dialysis patients averaged 27.1 procedures. Observed procedure times were used to calculate expected room-time hours required to service the monthly procedural volume and case mix per 100 dialysis patients. CONCLUSION: On average, 500 ambulatory dialysis patients will require the full-time use of an interventional suite and the services of a full-time technologist, nurse, and physician to provide necessary dialysis-related procedures. If resources cannot accommodate this volume, the quality and timeliness of care for these patients is jeopardized.

The procedural skills of rural hospital doctors.

OBJECTIVES: To describe the spectrum of procedures performed by general medical officers in South African rural hospitals, and the attitudinal issues associated with these tasks. DESIGN: A descriptive study combining quantitative and qualitative methods: a quantitative audit of operating theatre records of 15 rural hospitals in KwaZulu-Natal and 4 rural hospitals in Northern Province, and a qualitative analysis of 8 focus group discussions in which rural hospital doctors discussed their procedural work. OUTCOME MEASURES: Quantitative results included patient age, type of anaesthetic, type of procedure, and whether a separate anaesthetist was present or not for each recorded procedure performed in the operating theatre. Qualitative results comprised major and minor themes that arose from the focus group discussions. RESULTS: Quantitative results revealed a high proportion of obstetric and general surgical procedures, often performed by a single doctor acting as anaesthetist as well as surgeon. The range of surgical procedures undertaken varied widely between hospitals. Anaesthetic usage patterns revealed extensive use of ketamine and spinal anaesthetics, with relatively more general anaesthetics being administered in the Northern Province. Qualitative results revealed two scenarios in the rural hospital situation: one where doctors felt that they were coping and learning from the work under the supervision of peers or senior colleagues, and the other where they felt stressed by being alone and having to deal with emergencies, especially when short-staffed. CONCLUSIONS: The broad range of skills demanded in rural hospital practice requires specific preparation and ongoing support. Without it, a vicious cycle is established leading to poor output and morale. The phenomenon of the single-handed anaesthetist-surgeon that emerged from this study deserves specific attention, particularly with regard to staff shortages in rural areas. Under circumstances of adequate staffing and support, the rural hospital is an ideal learning site for generalists. This study has significant implications for the proposed introduction of obligatory vocational training for all medical graduates.

Bronchial artery embolization for the treatment of hemoptysis in patients with cystic fibrosis.

Hemoptysis is common in patients with cystic fibrosis (CF). Bleeding may vary in severity, ranging from minor blood-streaking of sputum to expectoration of significant quantities of blood. Major hemoptysis, defined as bleeding greater than 240 ml/24 h, represents a medical emergency. Bronchial artery embolization (BAE) is one of the treatment options for hemoptysis. We reviewed the 10-yr experience at the University of North Carolina Hospitals in the treatment of hemoptysis by BAE. Eighteen patients with CF were hospitalized on 29 occasions and underwent 36 BAE procedures for the control of hemoptysis. Most patients (n = 11) had very severe lung disease (FEV1 < 35%) with a high incidence (n = 9, 50%) of multi-drug-resistant bacteria. Fifteen patients (n = 33 procedures) were followed for a mean of approximately 22 mo after BAE. The overall efficacy of BAE for initial control of hemoptysis was 75% (n = 22) after one session, 89% (n = 26) after two sessions, and 93% (n = 27) after three sessions. The overall recurrence rate per episode was 46% (12/26 presentations in four patients) with a mean time for recurrence of approximately 12 mo. There was a high incidence (75%) of bleeding from nonbronchial systemic collateral vessels among patients (n = 7) who had undergone a previous BAE. There were two deaths associated with massive hemoptysis despite BAE. Three patients had transient neurologic deficits during BAE. We concluded that BAE is a relatively safe and effective means of treating significant hemoptysis in patients with CF.

Prospective randomized comparison of surgical versus endovascular management of thrombosed dialysis access grafts.

PURPOSE: Salvage of thrombosed prosthetic dialysis shunts can be performed using surgical or endovascular techniques. A prospective randomized trial was designed to compare the efficacy of these two methods in restoring dialysis access function. METHODS: One hundred fifteen patients with thrombosed dialysis shunts were randomized prospectively to surgical (n = 56) or endovascular (n = 59) therapy. In the surgical group, salvage was attempted with thrombectomy alone in 22% and with thrombectomy plus graft revision in 78%. In the endovascular group, graft function was restored with mechanical (82%) or thrombolytic (18%) graft thrombectomy followed by percutaneous angioplasty. RESULTS: Stenosis limited to the venous anastomotic area was the cause of shunt thrombosis in 55% of patients, and long-segment venous outflow stenosis or occlusion was the cause in 30%. In 83% of the surgical group and in 72% of the endovascular group, graft function was immediately restored (p = NS). The postoperative graft function rate was significantly better in the surgical group (p < 0.05). Thirty-six percent of grafts managed surgically remained functional at 6 months and 25% at 12 months. In the endovascular group, 11% were functional at 6 months and 9% by 12 months. Patients with long-segment venous outflow stenosis or occlusion had a significantly worse patency rate than those with venous anastomotic stenosis (p < 0.05). CONCLUSIONS: Neither surgical nor endovascular management resulted in long-term function for the majority of shunts after thrombosis. However, surgical management resulted in significantly longer primary patency in this patient population, supporting its use as the primary method of management in most patients in whom shunt thrombosis develops.

Comparison of measures for prospective identification of venous stenoses.

OBJECTIVE: To compare two methods, venous dialysis pressure (VDP) and intra-access static flow pressure (VPO), for the prospective identification of venous stenoses in high-risk PTFE grafts. DESIGN: Comparative. SAMPLE/SETTING: Twenty patients with upper extremity loop grafts in an outpatient chronic hemodialysis population. METHODS: VDP and VPO were measured for three consecutive treatments within subjects followed by angiography. VDP > 150 mmHg/200 ml/min, VPO > 0.40, and stenoses > 50% were considered positive findings. RESULTS: In paired t-tests, VPO identified elevated venous pressure more frequently than VDP in patients positive on angiography (mean difference = 77.8%, p < 0.0001). Frequency analysis yielded a sensitivity of 36% for VDP and 93% for VPO (p < 0.05). CONCLUSION: This study found that while VDP is the simpler method to use, VPO is significantly more accurate at predicting venous stenoses.

The first rib as a fluoroscopic marker for subclavian vein access.

PURPOSE: To determine whether the anatomic relationship between the subclavian vein (SCV) and the first rib is sufficiently constant to allow safe and reproducible fluoroscopically guided SCV puncture. MATERIALS AND METHODS: Forty-four subclavian venograms were obtained from 42 consecutive adult patients. Position and width of the SCV crossing over the first rib were recorded by using radial coordinates. Based on this anatomic study, 42 SCV access procedures were performed with use of the first rib as a fluoroscopic marker. Technical success, complications, number of 21-gauge needle passes, physician experience, and patients' body habitus were recorded. RESULTS: Mean angular position of SCV/first rib crossover was 94.7 degrees (standard deviation [SD], 7.42 degrees). Mean radial width of the SCV was 14.9 degrees (SD, 3.1 degrees). On 25 of the 44 subclavian venograms (60%), the SCV/first rib crossover lay within the 90 degrees-99 degrees segment, and on 36 of 44 (82%) it lay within the 85 degrees-104 degrees segment. Technical success in accessing the SCV was 100% (42 of 42 procedures). Two minor complications involved subclavian artery puncture with the 21-gauge needle without sequelae. The mean number of needle passes required was 2.86 (median, 1.7). There was no correlation between needle passes and patients' body habitus or physician experience. CONCLUSION: The SCV is reliably constant in its relation to the first rib. The first rib alone provides a reliable fluoroscopic marker for safe SCV access without the need for ultrasound guidance or peripheral contrast material administration.

Proximal venous outflow obstruction in patients with upper extremity arteriovenous dialysis access.

To evaluate the impact of central venous obstruction on upper extremity hemodialysis access failure, we retrospectively analyzed our recent experience in managing this problem. We reviewed 158 upper extremity hemodialysis access procedures performed in 122 patients during a 1-year period. Fourteen (11.5%) patients had central vein obstruction as the cause of severe arm swelling, graft thrombosis, or graft malfunction. All 14 patients had had bilateral temporary subclavian vein dialysis catheters and failed upper extremity arteriovenous access. Seventeen lesions were treated in 14 patients including eight subclavian vein occlusions, six subclavian vein stenoses, two internal jugular vein stenoses, and one superior vena cava stenosis. Twenty-one procedures were performed including 17 percutaneous transluminal balloon angioplasties (PTAs) with stent placement in 13, two axillary to innominate vein bypasses, and two axillary to internal jugular vein bypasses. All patients had resolution of symptoms. Thirteen (76%) PTAs were initially successful but in four (24%) cases it was impossible to recanalize the vein. Eight (47%) PTAs provided functional hemodialysis access for 2 to 9 months, two (12%) restenosed at 3 and 10 months and were successfully redilated, two occluded at 2 and 4 months and were unable to be recanalized, and one failed immediately after a successful PTA. Four PTA failures were followed by venous bypass, which remained patent and provided functional access 7 to 13 months after surgery. Of nine stenotic venous lesions six (67%) were successfully dilated without restenosis, whereas of eight occluded veins only two (25%) were successfully treated without recurrence. Temporary central hemodialysis catheters produce a significant number of symptomatic central vein obstructions in patients with upper extremity arteriovenous access.(ABSTRACT TRUNCATED AT 250 WORDS)

Variations in liver-colon anatomic relationship: relevance to interventional radiology.

PURPOSE: To determine the prevalence of significant variations in liver-colon anatomy in an unselected patient population and evaluate the potential effect of these variations on liver-related interventional procedures. PATIENTS AND METHODS: All abdominal computed tomographic (CT) scans were reviewed prospectively over a 4-month period. Cases that revealed variant hepatocolic anatomy were selected and analyzed for the position of the colon, gallbladder, and duodenum; liver morphology; and the anatomic relations of the right portal vein. RESULTS: Seventeen (3.3%) of 517 abdominal CT scans demonstrated variant hepatocolic anatomic relations. In seven cases, liver lobar morphology was normal, but the colon was interposed between the chest wall and the liver. The remaining 10 cases were characterized by hypoplasia or aplasia of one or both segments of the left lobe. In these cases the right portal vein was anteriorly exposed and was close to the gallbladder and transverse colon. In all 17 cases it was qualitatively judged that technical modifications might be needed in the performance of various interventional procedures, including percutaneous biliary drainage, biopsies, and transjugular intrahepatic portosystemic shunt creation. CONCLUSION: Variations in liver-colon anatomic relations in isolation or secondary to hepatic developmental anomalies may have a significant potential impact on the performance of various fluoroscopically guided hepatobiliary interventional procedures.