Dissolution of tungsten coils does not produce systemic toxicity,but leads to elevated levels of tungsten in the serum and recanalization of the previously occluded vessel

AIM: To evaluate the failure of mechanically detachable spirals produced from tungsten (MDS, Balt, Montmorency, France) and the toxicity of elevated levels of tungsten in the serum subsequent to their implantation. METHODS: We reviewed findings in 21 patients in whom tungsten coils had been used to occlude pathologic vessels, aneurysms and fistulas between 1996 and 1999. We achieved clinical follow-up, and measured renal and hepatic function, in 14 of the 21 patients. RESULTS: Decreased radiopacity of the coils was observed in 9 of 13 patients who had follow-up fluoroscopy during repeat cardiac catheterization. Repeat angiography of the vessel occluded by the coil was performed in 7 patients, 5 of whom showed recanalization. Levels of tungsten in the serum were analyzed 6 to 35 months after implantation of coils in 8 patients. The mean concentration was 6.43 micrograms/l, with a range from 2 to 14.4 micrograms/l, normal values being less than 0.2 microgram/l. CONCLUSION: Tungsten coils may dissolve over time and lead to markedly elevated levels of tungsten in the serum, with recanalization of previously occluded vessels. Despite lack of clinical and laboratory data in patients with elevated levels of tungsten in the serum, our study suggests that the clinical use of mechanically detachable coils produced from tungsten should no longer be recommended.     

Systemic heparinization does not prevent clot formation in coil embolization

Therapeutic transcatheter closure with Gianturco-type steel coils has been applied to a variety of vascular communications in children with congenital heart disease. Vessel closure depends upon successful thrombus formation around the coil. Since systemic anticoagulation with heparin is commonly used during catheterization and cardiac surgery, we studied the effect of systemic heparinization on the efficiency of vessel occlusion by coil embolization in lambs. Catheters inserted in femoral arteries were used to arteriographically locate and size 36 systemic arteries in 9 lambs weighing 4.2 to 7.4 kg. Twenty-four vessels were embolized prior to heparinization with 400 u/kg heparin, IV. Effective anticoagulation was demonstrated by post-heparin activated clotting time (ACT) values greater than 300 sec. Seven vessels (29%) were not successfully coil-embolized because of inadequate coil position or distant embolization of the coil; 17 (71%) of these vessels were shown to be successfully occluded by arteriography 6 to 77 min later. After a period of systemic heparinization ranging from 71 to 159 min, 9/17 arteries remained occluded, 7/17 could not be examined arteriographically due to early demise of the animal, and only 1/17 showed recanalization. A second group of 12 vessels were embolized after heparinization. Eight (75%) were successfully occluded, and 4 (25%) were not successfully coil-embolized because of inadequate coil position or coil embolization to distant arteries. We conclude that systemic heparinization had no measurable effect on occlusion rates in coil-embolized systemic arteries in the lamb. These data support the use of systemic heparinization, when indicated, during or following therapeutic coil embolization in children.     

Changes in coil morphology following transcatheter coil occlusion of the patent ductus arteriosus using a modified snare technique.

We observed a decrease in length of the Gianturco coils following transcatheter occlusion of the patent ductus arteriosus (PDA). Coil length was measured on chest radiograph within 24 hr of coil placement and compared to the length at the time of follow-up. Echocardiograms were also reviewed for evidence of duct recanalization. Twenty-seven patients met inclusion criteria. The median time to follow-up was 5 months (1--12 months). Twenty-four out of 27 (89%) patients had a decrease in coil length by 1.9 +/- 1.1 mm (P < 0.01). This was an average decrease of 16%. One patient had an increase in length and two patients had no change in coil length. Nineteen out of 27 patients had echocardiograms. Despite the change in coil length, there was no evidence of flow acceleration in the pulmonary artery or descending aorta. No patients had evidence of duct recanalization.     

Transcatheter coil embolization of a high-flow coronary artery fistula using 0.052-inch gianturco coils: a case report.

A giant, high-flow coronary fistula is usually difficult to treat by transcatheter coil embolization, but the 0.052-inch Gianturco coil, which is larger and has a stronger shape memory than conventional coils, is now available. Using this device and additional conventional coils, a high-flow coronary artery fistula in a healthy 31-year-old man was successfully embolized. The new Gianturco coil widens the indication for the transcatheter embolization of coronary artery fistulas.     

Percutaneous closure of patent ductus arteriosus using special screwing detachable coils

Jackson screwing detachable coils, developed for arterial and venous embolization, have been successfully employed recently for the percutaneous occlusion of patent ductus arteriosus (PDA). Special screwing detachable coils were designed for closure of the PDA, and the experience gained by their use is described in this report. Occlusion was attempted in 29 patients with a minimal ductal diameter of 0.9–4.2 mm. Coils were successfully placed in all 29 patients. One coil, which embolized 10 min after detachment, was retrieved. In 26 patients (89%), complete closure was achieved. Only 35 coils were placed in 29 patients. Residual shunts in three patients are minimal, detectable only on color-flow mapping. Screwing detachable coils for closure of PDA are safe and effective for occlusion of PDA with a minimal diameter <4.2 mm. Embolization of the coil is very rare. A high closure rate is achieved with a low number of placed coils. Cathet. Cardiovasc. Diagn. 41:386–391, 1997. © 1997 Wiley-Liss, Inc.     

Five-loop coil occlusion of patent ductus arteriosus prevents recurrence of shunt at follow-up.

Recent reports suggest reopening of the patent ductus arteriosus (PDA) after complete occlusion with three-loop Gianturco coils. We hypothesize that five-loop coils may produce a larger thrombus than three-loop coils, which will result in no or less probability of recanalization of PDA during follow-up. This study is designed to test this hypothesis. Follow-up echocardiographic and Doppler data of 30 patients who underwent five-loop coil occlusion of small to medium-sized PDA during a 33-month period ending December 1998 were examined. Thirty patients had no residual shunt on echo Doppler study on the day following the procedure and were followed for 6 to 30 months (median, 12) after coil implantation. At the last follow-up study, none of the patients had a residual shunt and left atrial size decreased. Careful pulsed, continuous wave, and color Doppler interrogation of left/main pulmonary artery junction and proximal descending aorta did not reveal any evidence for obstruction. The follow-up data suggest that complete occlusion of small- to medium-sized PDAs is feasible with five-loop coils without evidence for recanalization at a mean follow-up of 12 months. Much longer (2 to 5 years) follow-up data may be necessary to confirm these observations. We speculate that a greater degree of thrombosis is produced within the ductus by the five-loop coils, which in turn may be responsible for lack of shunt recurrence. We recommend use of five-loop instead of three-loop coils for transcatheter occlusion of small- to medium-sized PDAs.     

血管内栓塞治疗颅内破裂微小动脉瘤的疗效分析

目的探讨血管内栓塞治疗颅内破裂微小动脉瘤(瘤体最大径≤3mm)的方法和疗效。方法回顾性分析2006年1月—2011年12月,45例(45个)颅内破裂微小动脉瘤患者血管内栓塞治疗的资料。动脉瘤位于前交通动脉29例,后交通动脉11例,大脑前动脉A1段3例,小脑下后动脉2例。其中单纯采用弹簧圈栓塞治疗28例,血管内支架置入联合弹簧圈栓塞治疗8例,球囊辅助技术栓塞4例,双微导管技术栓塞3例,单纯血管内支架置入2例。结果①动脉瘤达到致密栓塞28例,大部分填塞15例,单纯支架成功置入2例。②术中并发症情况:1例发生术中出血,经继续填塞弹簧圈后,术后恢复良好。1例前交通动脉动脉瘤术中发生同侧大脑中动脉急性血栓形成,经溶栓后再通,但术后头部CT显示有皮质梗死,患者遗有左侧肢体偏瘫。对5例脑室积血患者行脑室外引流。③出院时改良Rankin评分:0～1分28例,2分14例,3～4分2例,5分1例。④DSA随访24例患者,随访时间6～12个月,无一例复发;CT血管成像随访12例,随访时间为2～6年,未见复发。结论血管内栓塞是治疗颅内破裂微小动脉瘤的有效方法,精确的微导管塑形,合适的弹簧圈选择,个性化的治疗方案和减少并发症是保证疗效的关键。     

Transcatheter closure of the patent ductus arteriosus: A comparative study between occluding coils and the Rashkind umbrella device

This study was performed to evaluate the efficacy of transcatheter coil closure of the patent ductus arteriosus in comparison to our experience with the Rashkind umbrella device. Transcatheter coil closure of the patent ductus arteriosus has been reported with encouraging results. We present our experience with ducti up to 5.0 mm in diameter and report the short-term follow-up. We compare the results with our previous experience with the Rashkind umbrella device. Seventy-one patients underwent transcatheter coil closure. Median age was 3.1 years, and median weight was 13.6 kg. Mean ductus diameter was 2.0 ± 1.1 mm. These were compared with 105 patients who underwent transcatheter closure using a single Rashkind umbrella device. The median age was 3.2 years and the median weight was 14.0 kg. The mean ductus diameter for this group was 2.1 ± 0.6 mm. The ductus murmur in the coil group disappeared in all patients. Immediate (≤24 h), complete closure was achieved in 89% of the coil group as compared to 71% for the Rashkind umbrella device group (P < 0.005). Closure rate for the coil group was 97% at the 6-month follow-up, vs. 82% for the Rashkind umbrella device group at the 6–12-month follow-up (P ≤ 0.05). In almost all patients requiring more than one coil, the ductus was crossed serially from the aortic end. All patients with ductus diameter ≥3.0 mm required two or more coils. Eleven coils in six patients embolized to the pulmonary arteries. All coils except one were retrieved with subsequent successful coil placement. Sixty-seven patients (94%) in the coil group were discharged in ≤24 h. Transcatheter closure of the patent ductus arteriosus using multiple coils is a more effective technique than the Rashkind umbrella closure and has excellent short-term results. This can be performed safely as an outpatient procedure. © 1996 Wiley-Liss, Inc.     

应用Cook可控弹簧栓子封堵动脉导管未闭

目的 :应用 Cook可控弹簧栓子封堵动脉导管未闭 （PDA）并对其疗效进行评价。方法 :全组共 10例 ,年龄 2～ 35 （平均 11.6 ）岁 ,体重 8～ 6 4（平均 30 .6 ） kg,PDA最窄处直径 1.4～ 3.2 （平均 2 .6 ） m m。经导管置入 Cook可控弹簧栓子封堵 PDA。封堵后 10 min行胸主动脉造影评价疗效。术后 3天、1月、6月及 12月行超声心动图检查观察有无残余分流及 PDA再通。结果 :全组技术成功率为 10 0 % ,术后 10 m in胸主动脉造影及术后 3d超声心动图未见残余分流。随访 12个月 ,均未发现 PDA再通及弹簧栓子移位。结论 :应用 Cook可控弹簧栓子封堵小型 PDA是一种安全、有效的非手术方法     

Bioptome-assisted coil occlusion of moderate-large patent ductus arteriosus in infants and small children.

Coil occlusion of patent ductus arteriosus (PDA), although inexpensive, is technically challenging for the moderate-large ducts in small children. Bioptome assistance allows better control and precision. We describe case selection strategies, technique, immediate and short-term results of bioptome-assisted closure of moderate-large (>/= 3 mm) PDA in 86 infants and children 6 mm (> 4 mm for children under 5 kg) and/or shallow ampullae (by echocardiography) underwent operation (n = 41). Specific technical modifications included use of long sheaths (5.5-8 Fr) for duct delineation and coil delivery, cutting of coils turns (51 patients) to accommodate the coils in the ampulla, and simultaneous delivery of multiple coils (n = 43). As far as possible, coils were deployed entirely in the ampulla. Median fluoroscopy time was 7.3 min (1.2-42 min). Successful deployment was feasible in all (final pulmonary artery mean pressures, 20 +/- 4.6 mm Hg). Coils embolized in 14 (16%) patients (all retrieved). Complete occlusion occurred immediately in 63 patients (73%) and in 77 patients (89%) at 24 hr. Three patients had new gradients in the left pulmonary artery. Follow-up (62 patients; median duration, 13 months) revealed small residual Doppler flows in 11 patients (18%) at the most recent visit. Bioptome-assisted coil occlusion of moderate-large PDA in selected infants and small children is feasible with encouraging results.     

The Safety and Feasibility of Re-treating Patients with Severe Emphysema with Endobronchial Coils: A Pilot Study

Severe emphysema patients who have been treated with endobronchial coils have been shown to initially benefit, but slowly decline in the years thereafter. Re-treating a patient with endobronchial coils could potentially lead to new improvements and may again reduce the rate of further decline. To our knowledge, until now, no results are published about patients who are re-treated. The primary aim of this study is to investigate the safety and feasibility of re-treating severe emphysema patients with endobronchial coils, using the PneumRx coil system. Furthermore, as secondary aim, we will evaluate the efficacy of re-treating these patients. Patients who at least 2 years ago were treated with endobronchial coils and responded clinically meaningful to this treatment were included in the study and re-treated. Safety was evaluated by the number of reported adverse events. Efficacy was evaluated 6 months after re-treatment, and measured by the change in quality of life, exercise capacity and pulmonary function testing. Eight patients were re-treated at a median of 1382 days (range 849–1545) after initial coil treatment with a median additional of 12 (10–15) coils per patient. During treatment, and until 6 months of follow-up, no unexpected adverse events occurred. Quality of life, exercise capacity and lung function did not change significantly 6 months after re-treatment. The results of this pilot study suggest that re-treating patients with endobronchial coils is feasible and safe. However, larger studies are needed to confirm these results and to investigate the efficacy and thus the clinical relevance.     

Transcatheter coil closure of pulmonary arteriovenous malformations in children

Pulmonary arteriovenous fistula (PAVF) is a rare vascular malformation of the lung that may lead to cyanosis, epistaxis, hemoptysis, and neurological deficits or cerebral abscess. The purpose of this study is to assess the effectiveness of percutaneous transcatheter embolization of PAVF in pediatric patients. Transcatheter embolization of PAVF using spring coils was performed in three patients (two males and one female) who presented between 1989 and 1999. The age at presentation ranged from 8 months to 3 years (mean 19.6 months). All patients had cyanosis and clubbing. Neurological, dermatological, or other cardiac manifestations were absent. The arterial oxygen saturations at presentation ranged from 60 to 72% (mean 64%). During eight procedures, multiple coils (total of 41 coils, average 14 coils per patient) were delivered to occlude the fistulas successfully. There was complete occlusion of the fistulas in all patients after the multiple interventions. The aortic saturations increased from a mean of 66% to a mean of 95%. Chest radiographs demonstrated dramatic regression of the pulmonary shadows in all three patients. There were no complications encountered during the procedures or during follow-up. Transcatheter coil embolization of PAVF is a safe and effective method of treatment in the pediatric age group. Patients may require multiple procedures to completely occlude the fistulas. Long-term follow-up is essential to ensure absence of recurrence due to recanalization.     

慢性饮水型砷中毒人群发、尿、血砷含量及皮肤色素细胞改变特点

目的调查慢性饮水型砷中毒病区砷中毒人群发、尿、血砷含量并进行皮肤病理学检查。方法采用高效液相色谱法测定水砷含量;采用超低温捕获-还原气化-原子吸收分光光度法测定发、尿、血砷含量;皮肤样本进行HE病理学检查。结果砷中毒患者饮用水中三价无机砷(AsIII)、五价无机砷(AsV)、有机砷及总砷(tAs)水平均显著高于无砷暴露对照人群;砷中毒患者毛发中无机砷(iAs)、二甲基砷(DMA)及tAs水平,尿中iAs、甲基砷(MA)、DMA及tAs水平,血液中MA及DMA水平均显著高于相应无砷暴露对照人群。发砷、尿砷及血砷水平男女间无显著差异。皮肤HE病理切片中黑色素细胞出现凋亡并有黑色素产生增多现象。结论砷性皮肤损伤可能与血液中高水平的MA关系密切;砷性皮肤色素脱失可能与黑色素细胞发生凋亡有关。     

新型机械可解脱弹簧圈在颅内破裂宽颈动脉瘤栓塞术中的初步应用

目的探讨一种新型可解脱弹簧圈(Prime FC弹簧圈)在颅内破裂宽颈动脉瘤栓塞术中应用的安全性和有效性.方法回顾性分析2020年9月至2021年1月期间连续收治的应用Prime FC弹簧圈成篮栓塞治疗的22例颅内破裂宽颈动脉瘤患者的临床资料,瘤颈宽度>4 mm或瘤体/瘤颈<2.入院时改良Rankin量表(mRS)评分0...     

Long-term outcome of transcatheter coil closure of small to large patent ductus arteriosus

Coil closure of patent ductus arteriosus (PDA) has become an accepted alternative to surgical closure in most pediatric cardiac centers. However, little is known about the mid- to long-term outcome of this procedure. Therefore, we evaluated the immediate, short-, and long-term outcome of transcatheter coil closure (TCC) of PDA using single or multiple Gianturco coils or the Gianturco-Grifka Vascular Occlusive Device (GGVOD). One hundred forty-nine patients underwent an attempt at TCC of their PDAs at a median age of 2.4 years (2 weeks to 55 years) and median weight of 13.5 kg (2.3–87 kg). There were 33 patients < 1 year of age. The median PDA minimal diameter was 2 mm (0.4–7 mm) with 26 patients whose PDA minimal diameter was > 4 mm. A 4 Fr catheter was used for coil deployment in 136 patients, a 3 Fr in 4, and an 8 Fr in 4 patients who received the GGVOD. A single coil was used in 77 patients and multiple coils (2–6) were used in 66 patients. One hundred forty-six patients had successful closure (142 had immediate complete closure and 4 had residual shunt), 3 patients failed the initial attempt (2 underwent surgical ligation and 1 had a successful second attempt a year later). Of the four patients with residual shunt, three underwent a second procedure with implantation of 1–3 coils resulting in complete closure in all and one patient had spontaneous resolution of the residual shunt. Complications were encountered in nine patients: six had coil migration with successful retrieval in four; two had left pulmonary artery stenosis (2.4 kg and 6.3 kg infants), and one patient had loss of femoral arterial pulse. The median fluoroscopy time was 16 min (2–152 min). One hundred forty-two patients had the procedure as an outpatient, five patients stayed greater than 24 hr, and two of these patients were in hospital for 1 month for noncardiac reasons. At a median follow-up interval of 3.0 years (1 month to 5.1 years), there were no episodes of delayed coil migration, delayed recanalization, thromboembolic episodes, or bacterial endocarditis. Lung perfusion scans performed at a median follow-up interval of 1.6 years in 31 patients who received multiple coils revealed 45% ± 5% blood flow to the left lung. Long-term follow-up of coil closure of PDA indicates that the technique is safe and effective for most pa-tients with PDA up to a diameter of 7 mm. Cathet. Cardiovasc. Intervent. 47:457–461, 1999. © 1999 Wiley-Liss, Inc.     

Andersson lesions of whole spine magnetic resonance imaging compared with plain radiography in ankylosing spondylitis

The objective of this study was to identify the characteristics of Andersson lesions using whole spine magnetic resonance imaging (MRI) compared with plain radiography in ankylosing spondylitis (AS). A total of 62 patients with AS who had undergone whole spine MRI and plain radiography were retrospectively enrolled in this study. We compared the number of discovertebral units (DVUs) with Andersson lesions with clinical and radiographic indices such as erythrocyte sediment rate (ESR), C-reactive protein (CRP), the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), the Bath Ankylosing Spondylitis Functional Index (BASFI), and modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). Fifty-three patients (85.5 %) by whole spine MRI and 23 patients (37.1 %) by plain radiography had at least one Andersson lesion. We found 129 DVUs with Andersson lesions (11.1 %) by MRI and 35 DVUs by plain radiography over all the spine levels. Andersson lesions by MRI were most commonly detected at the lower thoracic spine (from T7-8 to T12-L1). Among the 151 total Andersson lesions by whole spine MRI, 41 were identified as central disc type, 26 as anterior peripheral disc type, 44 as posterior peripheral disc type, and 40 as diffuse disc type. However, the number of Andersson lesions did not correlate with ESR, CRP, BASDAI, BASFI, or mSASSS (p > 0.05 for all). Our study indicates that the presence of Andersson lesions in patients with AS is clearly underestimated. MRI is a superior technique for detecting early Andersson lesions compared with plain radiography.     

Follow-up of coil occlusion of patent ductus arteriosus

Objective. We sought to determine the prevalence and fate of residual ductal shunting following coil occlusion of patent ductus arteriosus.Background. Although transcatheter coil occlusion of patent ductus arteriosus has gained popularity, few follow-up data have been reported.Methods. A review of 75 patients who underwent coil occlusion was performed. Residual shunting was investigated by Doppler echocardiography in follow-up. Angiograms were reviewed to obtain minimal ductal diameter and ductal angiographic type.Results. Residual shunts were found in 31 patients (41%) on the day of the procedure, and of these, spontaneous closure was noted in 17 (55%) at 2 weeks to 20 months of follow-up. Of the 75 patients studied, 5 (7%) required a second coil procedure, and 10 (13%) remained with persistent residual shunts at most recent follow-up. Actuarial analysis estimated a 6 ± 5% prevalence of residual shunts 20 months after a single coil procedure and 3 ± 3% after all coil procedures. Minimal ductal diameter was associated with immediate complete ductal occlusion by a single coil. These patients had significantly smaller (p = 0.003) minimal ductal diameters (1.2 ± 0.7 mm) than those who required two coils during their initial procedure to achieve immediate occlusion (1.9 ± 0.7 mm), those who required a second coil procedure (2.0 ± 0.9 mm), those who had spontaneous closure of residual shunts (1.9 ± 0.7 mm) and those with persistent residual shunts (2.0 ± 0.9 mm). No association was identified between ductal angiographic type and outcome of coil occlusion. No late adverse clinical events of coil occlusion or evidence of recanalization was found.Conclusions. Small residual shunts are common after coil embolization of patent ductus arteriosus, but most close spontaneously. Actuarial analysis estimates complete closure in 94% at 20 months, and reintervention was required in only 7% of patients.     

Influences of supplementary dietary tungsten on methionine metabolism in rabbits fed a low-cholesterol plus methionine diet

Hyperhomocysteinemia results from an impaired methionine metabolism. Sulfite oxidase, which is an important enzyme in methionine metabolism, contains molybdenum. In contrast, tungsten has a molybdenum-antagonistic effect. Thus, we hypothesized that dietary tungsten may decrease plasma homocysteine levels and influence methionine metabolism. Male New Zealand White rabbits (n=15) were fed a low-cholesterol basal diet and then placed on three different diets: 0.1% cholesterol (Chol), Chol plus 1% methionine (Met), and Chol plus Met plus 0.1% tungsten (W). The animals received these diets for 20 weeks. Biochemical tests of blood and urine were performed. Plasma homocysteine levels were significantly lower in the Chol+Met+W group than in the Chol+Met group. Plasma levels of total cholesterol, triglyceride, lipid peroxide, and urinary 24-h taurine concentrations were higher in the Chol + Met + W group than in the Chol + Met group. In comparison, concentrations of 2, 3-diphosphoglycerate (2, 3-DPG), reduced glutathione (GSH) in erythrocytes, and urinary 24-h SO4(2) were lower in the Chol+Met+W group than in the Chol+Met group. From these results, tungsten could be expected to exhibit an antiatherogenic effect. Conversely, it may have effects on atherogenic factors. Thus, tungsten may play a number of roles in the methionine metabolism.     

Transcatheter closure of a huge pulmonary arteriovenous fistula with embolization coils

A 46-year-old female with bilateral pulmonary arteriovenous fistulas was treated with Gianturco coil occlusion. The small right lung fistula was closed with a 6 mm coil, whereas the huge left lung fistula was occluded with three coils (one 10-mm and two 8-mm). Angiography 3 d later demonstrated recanalization of the left fistula. Two 8 mm coils were inserted to achieve complete obstruction again. She developed pulmonary infarction in the left lung 2 d later, which recovered without sequelae. We conclude that coil embolization for huge pulmonary arteriovenous fistula is feasible but may result in pulmonary infarction. Cathet. Cardiovasc. Diagn. 42:286–289, 1997.© 1997 Wiley-Liss, Inc.     

Techniques for analytical testing of unconventional samples.

Forensic scientists have long detected the presence of drugs and their metabolites in biological materials using body fluids such as urine, blood and/or other biological liquids or tissues. For doping analysis, only urine has so far been collected. In recent years, remarkable advances in sensitive analytical techniques have encouraged the analysis of drugs in unconventional biological samples such as hair, saliva and sweat. These samples are easily collected, although drug levels are often lower than the corresponding levels in urine or blood. This chapter reviews recent studies in the detection of doping agents in hair, saliva and sweat. Sampling, analytical procedures and interpretation of the results are discussed in comparison with those obtained from urine and blood samples.