Selective release of miRNAs via extracellular vesicles is associated with house-dust mite allergen-induced airway inflammation.

BACKGROUND: MicroRNAs (miRNAs) may facilitate cell-to-cell communication via extracellular vesicles (EVs). The biological roles of miRNAs in EVs on allergic airway inflammation are unclear. METHODS: Airway-secreted EVs (AEVs) were isolated from bronchoalveolar lavage fluid (BALF) of control and house-dust mite (HDM) allergen-exposed HDM-sensitized mice. The expression of miRNAs in AEVs or miRNAs and mRNAs in lung tissue was analysed using miRNA microarray. RESULTS: The amount of AEV increased 8.9-fold in BALF from HDM-exposed mice compared with that from sham-control mice. HDM exposure resulted in significant changes in the expression of 139 miRNAs in EVs and 175 miRNAs in lung tissues, with 54 miRNAs being common in both samples. Expression changes of these 54 miRNAs between miRNAs in AEVs and lung tissues after HDM exposure were inversely correlated. Computational analysis revealed that 31 genes, including IL-13 and IL-5Ra, are putative targets of the miRNAs up-regulated in AEVs but down-regulated in lung tissues after HDM exposure. The amount of AEV in BALF after HDM exposure was diminished by treatment with the sphingomyelinase inhibitor GW4869. The treatment with GW4869 also decreased Th2 cytokines and eosinophil counts in BALFs and reduced eosinophil accumulation in airway walls and mucosa. CONCLUSION: These results indicate that selective sorting of miRNA including Th2 inhibitory miRNAs into AEVs and increase release to the airway after HDM exposure would be involved in the pathogenesis of allergic airway inflammation.

Effect of radiation monitoring method and formula differences on estimated physician dose during percutaneous coronary intervention.

BACKGROUND: Currently, one or two dosimeters are used to monitor radiation exposure in most cardiac laboratories. In addition, several different formulas are used to convert exposure data into an effective dose (ED). PURPOSE: To clarify the effect of monitoring methods and formula selection on the estimated ED for physicians during percutaneous coronary interventions (PCIs). MATERIAL AND METHODS: The ED of physicians during cardiac catheterization was determined using an optically stimulated luminescence dosimeter (Luxel badge). Two Luxel badges were worn: one beneath a personal lead apron (0.35-mm lead equivalent) at the chest and one outside of the apron at the neck. RESULTS: The difference in the average ED of seven physicians was approximately fivefold (range 1.13-5.43 mSv/year) using the six different formulas in the clinical evaluation. The estimated physician ED differed markedly according to both the monitoring method and formula selected. CONCLUSION: ED estimation is dependent on both the monitoring method and the formula used. Therefore, it is important that comparisons among laboratories are based on the same monitoring method and same formula for calculating the ED.

Bakery flour dust exposure causes non-allergic inflammation and enhances allergic airway inflammation in mice.

BACKGROUND: Baker's asthma is one of the most commonly reported occupational lung diseases in countries where fresh bread is baked daily in large quantities, and is characterized by rhinitis, bronchial hyperresponsiveness, and reversible airflow obstruction. Epidemiological studies have identified pre-existing atopy as an important risk factor for developing baker's asthma, yet the aetiology and pathogenesis of baker's asthma remain poorly understood. OBJECTIVE: We sought to develop a mouse model of baker's asthma that could be used to characterize the development and progression of baker's asthma. METHODS: We were unable to sensitize mice to bakery flour dust or flour dust extract. We assessed total inflammatory cells, cellular differential, total serum IgE and the pro-inflammatory cytokine response to oropharyngeally instilled bakery flour dust or flour dust extract by itself or in the context of ovalbumin (OVA) sensitization and challenge. RESULTS: Both bakery flour dust and flour dust extract consistently elicited a neutrophilic inflammation in a Toll-like receptor 4-independent manner; suggesting that endotoxin is not playing a role in the inflammatory response to flour dust. Moreover, bakery flour dust and dust extract significantly enhance the inflammatory response in OVA-sensitized and challenged mice. CONCLUSIONS: Bakery flour dust and flour dust extract are strongly pro-inflammatory and can cause non-allergic airway inflammation and can enhance allergen-mediated airway inflammation.

Long-term right ventricular volume overload increases myocardial fluorodeoxyglucose uptake in the interventricular septum in patients with atrial septal defect.

BACKGROUND: Several studies have shown that long-term right ventricular (RV) overload in animal models alters myocardial energy substrate metabolism. However, whether long-term RV volume overload alters this metabolism in the human is unclear. METHODS AND RESULTS: We performed positron emission tomography with [(18)F]fluorodeoxyglucose (FDG) and single-photon emission tomography (SPECT) with [(201)Tl]TlCl (Tl) and [(123)I]15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) in 11 patients with atrial septal defect (ASD) and 11 control subjects. In the FDG study, we calculated myocardial metabolic rate of glucose (MMR) in interventricular septum (IVS) and left ventricular (LV) free wall. MMR was significantly increased in IVS compared with LV free wall in the ASD patients (420+/-35 versus 333+/-32 mol x kg(-1) x min(-1); P<0.05) but not in the control group (347+/-27 versus 357+/-25 mol x kg(-1) x min(-1)). In both ASD and control groups, SPECT count was not significantly different between IVS and LV free wall in Tl (ASD, 160+/-11 versus 177+/-12; control, 141+/-12 versus 157+/-14 counts per 15 minutes) and BMIPP studies (ASD, 203+/-14 versus 212+/-18; control, 162+/-16 versus 176+/-16 counts per 15 minutes). MMR in the IVS/LV free wall ratio in the ASD group significantly correlated with indices related to RV volume overload. CONCLUSIONS: Given the assumption that long-term RV volume overload did not affect the lumped constant, the present study suggests that, unlike myocardial perfusion or fatty acid analogue uptake, myocardial glucose utilization in IVS relative to LV free wall is increased in relation to long-term RV volume overload in patients with ASD.

Retinoic acid differentially regulates interleukin-1beta and interleukin-1 receptor antagonist production by human alveolar macrophages.

Mechanism in the pathogenesis of acute respiratory distress syndrome which is the clinical feature of pulmonary involvement in retinoic acid (RA) syndrome has been investigated. Pulmonary infiltration of matured neutrophils and leukemic cells is thought to be associated with the pathogenesis of pulmonary involvement in RA syndrome; however. Little is known about the mechanism in pulmonary infiltration of these cells. In the present study, we examined the effect of RA on IL-1beta and IL-1ra production by human alveolar macrophages in order to clarify the mechanism in pulmonary infiltration of neutrophils, since IL-1 has been shown to initiate neutrophil recruitment into the lung through up-regulated expression of adhesion molecules on vascular endothelium. RA enhanced IL-1beta and inhibited IL-1ra production by 4beta phorbol 12beta-myristate-13alpha acetate (PMA)- and lipopolysaccharide (LPS)-stimulated human alveolar macrophages. These results show that RA differentially regulates IL-1beta and IL-1ra production by alveolar macrophages and indicate that an imbalanced production between IL-1beta and IL-1ra may contribute to initiating neutrophil recruitment into the lung through up-regulated expression of adhesion molecules.

Elevated serum leptin concentrations in women with components of multiple risk factor clustering syndrome.

This cross sectional study was undertaken to determine whether serum leptin levels were associated with multiple risk factor (MRF) clustering syndrome. We examined the relationship between serum leptin concentrations and blood pressure (BP), serum lipids levels, calculated insulin resistance (HOMA-ratio) and adiposity among 581 Japanese adult women. The serum leptin was increased in female subjects with systolic (> or =160 mmHg) and diastolic > or =90 mmHg) hypertension compared with the normotensive females (mean+/-SE; 9.3+/-0.5 vs 7.7+/-0.3; 10.2+/-0.6 vs 7.1+/-0.3 ng/ml, both p<0.001). Serum leptin was elevated in those with hyper-cholesterolemia (C; > or =220 mg/dl) and triglyceridemia (TG; > or =150 mg/dl) compared with the normolipidemia (9.4+/-0.4 vs 7.8+/-0.3; 11.7+/-0.6 vs 7.5+/-0.2 ng/ml, both p <0.001). Serum leptin was also elevated in those with adiposity (BMI > or =26.4 kg/m2) and insulin resistance (HOMA-ratio > or =2.5) compared with the normal females (14.8+/-0.7 vs 5.2+/-0.2; 11.3+/-1.1 vs 7.1+/-0.4ng/ml, both p<0.001). Even after adjusting for BMI or percent body fat mass (BFM), leptin levels remained to be elevated significantly in all these diseases. There was a positive correlation between serum leptin and systolic, diastolic BP, TC, TG, BMI, BFM, IRI and HOMA-ratio (r=0.12, p=0.005; r=0.24, p<0.0001; r=0.19, p<0.0001; r=0.35, p<0.0001; r=0.72, p<0.0001; r=0.73, p<0.0001; r=0.47, p< 0.0001; r=0.44, p<0.0001), and a negative correlation with HDL-C levels (r= -0.20, p< 0.0001). These correlations were also observed in leptin levels after adjusting for the BMI or BFM. Multiple regression analysis showed that BFM, HOMA-ratio and TG were significant determinants of leptin concentration before (t=12.6, p<0.0001; t=3.33, p=0.001; t=3.22, p=0.001) and after adjusting for BMI or BFM. These results suggest that because serum leptin levels were elevated in components of MRF clustering syndrome, leptin may have a pathophysiological role in MRF clustering syndrome.

Functional MR imaging of cortical activation of the cerebral hemispheres during motor tasks.

PURPOSE: We used functional MR imaging to evaluate cortical activation in the precentral, central, and postcentral regions of the contralateral and ipsilateral cerebral hemispheres during left- and right-handed motor tasks. METHODS: Ten healthy right-handed volunteers were studied with echo-planner MR imaging (1.5 T) while performing alternating finger apposition tasks with both hands. During the hand tasks, the areas of activated pixels were compared between subregions (precentral, central, and postcentral) of the contralateral and ipsilateral sensorimotor cortex. RESULTS: The activated area of the contralateral sensorimotor cortex was significantly larger than that of the ipsilateral cortex during tasks with either hand, whereas the ipsilateral activated area was significantly larger during the left-handed task than during the right-handed task. Ipsilateral activation was greatest in the precentral region, less in the central region, and least prominent in the postcentral region. CONCLUSIONS: Our results confirmed those of previous investigators that ipsilateral activation is more pronounced during left-sided movements than during right-sided movements. The variation in activation of the precentral, central, and postcentral subregions suggests different roles of the ipsilateral and contralateral hemispheres during motor tasks.

Diagnostic value of 201Tl-single-photon emission computerized tomography studies in cases of posterior fossa hemangioblastomas.

OBJECT: The 201Tl uptake index was evaluated for its usefulness in formulating a diagnosis of hemangioblastoma. Thallium-201-single-photon emission computerized tomography (SPECT) studies were performed in nine patients harboring hemangioblastomas in the posterior fossa and in five patients (six lesions) with gliomas in the posterior fossa. METHODS: The 201Tl uptake index was defined as the ratio of mean counts of isotope per pixel in the tumor to mean counts of isotope per pixel in the homologous region of the healthy brain. The 201Tl uptake indices of the early image (TlE) and that of the delayed image (TlD) were calculated. The isotope retention index (RI) was calculated as (TlE - TlD)/TlE. The TlE was 2.7 +/- 0.7 in hemangioblastomas and 2.9 +/- 1.7 in gliomas (mean +/- standard deviation). The TlD was 1.5 +/- 0.4 in hemangioblastomas and 2.4 +/- 1.6 in gliomas. There were no significant differences between hemangioblastomas and gliomas when TlEs and TlDs were compared. The isotope RI was 0.43 +/- 0.07 in hemangioblastomas and 0.15 +/- 0.1 in gliomas, showing a significantly higher RI in hemangioblastomas compared with gliomas (p < 0.01). CONCLUSIONS: Thallium-201 washout is significantly faster in hemangioblastomas. Hemangioblastoma is biologically benign, but contains a rich capillary network that forms a hypervascular tumor bed. Variations in its appearance on magnetic resonance images may cause difficulties in the differential diagnosis of hemangioblastoma. Thallium-201 SPECT studies can be used to distinguish hemangioblastomas from gliomas in the posterior fossa.

Mitogen-activated protein kinase involves neutrophil elastase-induced morphological changes in human bronchial epithelial cells.

Neutrophil elastase (NE) promotes the detachment of airway epithelial cells; however, changes in overall morphology of NE-stimulated bronchial epithelial cell (BEC) monolayer are different from trypsin stimulation. Ras/Raf-initiated-mitogen activated protein kinase (MAPK) also known as extracellular signal-regulated kinase, pathway regulates integrin functions which participate in regulating attachment and detachment of cell and cellular morphology. However, little is known about the role of MAPK in NE-induced changes in overall morphology of BEC. In the present study, we examined the role of MAPK in NE-induced changes in overall morphology of BEC monolayer. To this end, we examined changes in cellular morphology and MAPK activation in NE-stimulated BEC monolayer, and the effect of PD 98059 as the specific inhibitor for MAPK kinase-1 (MEK-1, the upstream regulator of MAPK) on NE-induced changes in cellular morphology and MAPK activation. The results showed that in stimulation of NE, BECs detached and gaps developed, and MAPK activation was observed. PD 98059 attenuated NE-induced changes in cellular morphology as well as MAPK activation. These results indicated that in addition to proteolytic activity of NE on extracellular matrix (ECM), NE-activated MAPK pathway, at least in part, is involved in NE-induced changes in overall morphology and the detachment of BEC monolayer.

Grepafloxacin inhibits tumor necrosis factor-alpha-induced interleukin-8 expression in human airway epithelial cells.

We examined the effect of grepafloxacin (GPFX), a new fluoroquinolone antimicrobial agent, on interleukin-8 (IL-8) expression in tumor necrosis factor-alpha (TNF-alpha)-stimulated human airway epithelial cells (AEC). GPFX inhibited IL-8 protein production as well as mRNA expression in a concentration-dependent manner (2.5 - 25 micro g/ml), but the inhibition of IL-8 expression by corresponding concentrations of GPFX to serum and airway lining fluids was not complete. We discuss the modulatory effect of GPFX on IL-8 production in the context of its efficacy on controlling chronic airway inflammatory diseases.

[Gastric emptying of semi-solid meal in normal man with special reference to relationship between plasma acetoaminophen concentrations and gastric emptying time].

Correlation between gastric emptying time measured by a radioisotope method and plasma acetoaminophen level was studied in 11 preoperative early gastric cancer in semisolid meal. A significant correlation was found between both gastric emptying half-time and plasma acetoaminophen level at 30, 45 minutes after ingestion of meal, and plasma acetoaminophen level at maximum. We conclude that acetoaminophen analysis is useful to measure gastric emptying at semisolid meal.

Mutagenicity in Salmonella typhimurium tester strains of XAD-2-ether extract, recovered from Katsura River water in Kyoto City, and its fractions.

The mutagenic activity of XAD-2-ether extracts recovered from Katsura River water at monthly intervals during September to December 1980 was tested on S. typhimurium TA1538, TA1535, TA98 and TA100. The extracts showed strong mutagenic activity towards TA1538 nd TA98, especially in the presence of S9 mix. They were more active to TA1538 than to TA98. Some of each of the XAD-2-ether extracts were pooled and separated into neutral, basic and acidic fractions, and their mutagenic activities were tested on TA1538 and TA98 to determine their contribution to the total mutagenic activity of the parent extract. The neutral fraction was responsible for most of the total mutagenic activity of the parent extract. Although the basic fraction was only 5.4% by weight of the parent extract, it was much more mutagenic than any other fraction. Its contribution to the total mutagenic activity was higher than the acidic fraction which was 30.5% by weight of the parent extract.

The origin of hypsarrhythmia and tonic spasms in West syndrome: evidence from a case of porencephaly and hydrocephalus with focal hypsarrhythmia.

We report on a 3-year-old girl with West syndrome and with focal hypsarrhythmia. The left hemisphere of the patient was virtually completely defective and continuous hypsarrhythmia was only seen in the residual right frontal cortex, where an interictal single photon emission computed tomography (SPECT) showed hyperperfusion. Despite a focal epileptic pattern, the tonic spasms were quite symmetrical. In our patient, spasms might not require the sensorimotor cortex, but the brainstem containing the descending pathways that control spinal reflexes and other infratentorial structures seem to be essential for the occurrence of spasms. This is in accordance with the result of an ictal SPECT that showed hyperperfusion of the brainstem and cerebellum. These findings suggest that hypsarrhythmia originates from cortical lesions, while subcortical structures may be primarily responsible for the tonic spasms in this patient.

The perfusion defect seen with SPECT in West syndrome is not correlated with seizure prognosis or developmental outcome.

We used interictal single photon emission computed tomography (SPECT) on 40 patients with West syndrome to determine whether cortical perfusion abnormalities are closely related to the development of West syndrome and whether they are correlated with the long-term seizure prognosis or the developmental outcome. Localized cortical perfusion abnormalities were seen in 24 patients (60%), while 15 patients (38%) were classified as normal. The remaining patient showed hyperperfusion of the basal ganglia bilaterally. Of 24 patients with localized perfusion abnormalities, unifocal cortical hypoperfusion was present in 11, multifocal hypoperfusion in 10, multiple cortical hypo- and hyperperfusion in one, hyperperfusion of the bilateral frontal cortices and brain stem in one, and focal hyperperfusion in the residual frontal cortex in one. For statistical analysis, we focused on 26 patients (cryptogenic; 10, symptomatic; 16), who were followed for more than 2 years after the onset of tonic spasms (mean 5.0 years). The results showed that focal cortical perfusion abnormalities were not correlated with the long-term seizure prognosis, the developmental outcome, or the response to ACTH therapy. In agreement with previous reports, the results of interictal SPECT suggested that focal cortical lesions play an important role in the development of West syndrome. However, statistical analysis showed that the existence of cortical dysfunction as defined by SPECT did not predict the seizure prognosis or the developmental outcome.

Evaluation of neuronal loss in adult moyamoya disease by 123I-iomazenil SPECT.

BACKGROUND: Central benzodiazepine (BZD) receptor imaging is effective to evaluate neuron density in the pathological brain cortex. This study used BZD receptor imaging to evaluate neuronal damage in adult ischemic moyamoya disease. METHODS: Single photon emission computed tomography and a novel tracer, 123I-iomazenil, were used to measure BZD receptor density in the brain. Evaluation of early and late images was performed in three asymptomatic, unoperated patients, and six mildly symptomatic, operated patients. RESULTS: Uptakes in the frontal, parietal, and occipital lobes of symptomatic patients were significantly lower (p<0.05) than those of asymptomatic patients. The late image/ early image count ratios (L/E ratios) of asymptomatic patients were relatively constant (mean, 0.571; range, 0.550-0.581) in all regions of interest. In contrast, the L/E ratios of symptomatic patients were not uniform. CONCLUSIONS: The neuron density was preserved in adult asymptomatic patients despite harboring moyamoya disease. In contrast, the neuronal density was decreased in symptomatic patients even though their symptoms were mild and they had undergone revascularization.

Mutagenic potential of laboratory chlorinated river water.

Sample water was taken from a river and chlorinated at a concentration of 5 mg 1(-1) chlorine for 20 h in the laboratory in order to examine the effect of chlorination on the mutagenic potential of organic extracts that were recovered using XAD-2 resin and diethyl ether. It was found that the XAD extracts recovered from the river water showed per se strong mutagenic activity, in the presence of S-9 mix, towards Salmonella typhimurium TA 1538. When the mutagenic activity of the XAD extracts was related to the initial water volume, chlorination increased both the direct-acting and the S-9 dependent mutagenic activity. This suggests that chlorination produced de novo direct-acting and S-9 dependent mutagens and/or increased pre-existing mutagenic activities. In addition, in this study XAD extracts recovered from chlorinated and unchlorinated river water were divided into a neutral, basic and acidic fraction respectively. When the mutagenic activity of each fraction was related to the initial water volume, the neutral fraction showed the most marked increase in mutagenic activity with, and without, the S-9 mix in the chlorinated river water.

Isolation of mutagenic components by high-performance liquid chromatography from XAD extract of water from the Nishitakase River, Kyoto City, Japan.

In order to determine the concentrations of mutagenic pollutants in water samples taken from the Nishitakase river in Kyoto City, Japan, the organic fraction was concentrated by XAD adsorption followed by elution with ethyl ether. Salmonella typhimurium tester strains TA1538 and TA98 were used fro detecting mutagenic activity. Mutagenic fractions, separated by a liquid-liquid fractionation and two consecutive runs with thin layer chromatography (TLC), were analysed using high-performance liquid chromatography (HPLC). The results obtained indicated that at least six different frameshift mutagens, all requiring metabolic activation, were present in the river water. Interestingly, all the mutagens isolated showed more pronounced mutagenic activity in TA1538 than in TA98, which is known to be more sensitive for most frameshift type mutagens.

Cine viewing of abdominal CT.

A few studies have been reported that CT cine viewing on the CRT is superior to film-based viewing of CT images (Seltzer et al., Radiology 197 (1994) 119; Bonaldi et al., Am. J. Roentgenol. 170 (1998) 373; Tillich et al., Am. J. Roentgenol. 169 (1997) 1611). The purpose of our study is to know how to use cine viewing of abdominal CT. Thirty CT studies on the abdomen with both precontrast and postcontrast images were examined. The suitable rate of cine viewing ranged from 1 to 6 frames per second according to the size, the contrast and the complexity of the anatomical structures, and the slice thickness. For small or complex structures, checking each image might be required to know the full detail of them. Positional sorting among multiphase images, which is followed by consecutive display of a precontrast image, postcontrast early and late phase images at one position and so on, is useful to see the dynamic pattern of enhancement of the anatomical structures. However, there was no significant difference between cine viewing and film-based viewing concerning both the detectability of the anatomical structures and the conspicuity of enhancement of the liver and the pancreas, so that cine viewing might be an alternative to film-based viewing for CT diagnosis of the abdomen.

[An adult case of Chédiak-Higashi syndrome with parkinsonism and marked atrophy of the central nervous system].

Chédiak-Higashi syndrome (CHS) is often a fatal disease of childhood characterized by oculocutaneous forms of albinism with congenital gigantism of peroxidase granules, granulation anomaly of leukocytes, hereditary gigantism of cytoplasmic organelles and a marked susceptibility to infections. A few patients have survived to age 20 years. A 39-year-old woman developed tremor and gait disturbance at age 22 years. At age 25 years, she was admitted to the Hospital for evaluation. Mental impairment, horizontal nystagmus, bradyphrenia, cogwheel rigidity, tremor at tongue, mandible and hands, bradykinesia, and unsteady gait were found and a juvenile parkinsonism was diagnosed. However, there was no favorable response by levodopa therapy. She became unable to walk at age 33 years. On admission, Oct. 27, 1988, at age 39 years, she was bedridden with a posture of decorticate rigidity. She was found to have partial depigmentation of the retina and choroid, pale and atrophic optic disc and subluxation of the mandible, Onuaguluchi's finger deformities and pes cavus. Neurological examination disclosed that she was alert but had marked difficulty in speaking. The communication was only possible by giving a sign of grasping of the left hand. The patient also showed oculogyric crisis, dystonic rigidity of the neck, diffuse muscular atrophy, complete paraplegia and decreased deep tendon reflexes with Babinski sign. On laboratory studies, at age 39, the white cells count was decreased (2,510/mm3), the hemoglobin level was 10.3 g/dl, the serum iron was 12 micrograms/dl, IgG 2,828 mg/dl, IgA 1,002 mg/dl, and the activity of natural killer cell was profoundly decreased (2%, normal; 18-40). Hematological examination revealed peroxidase positive giant granules in leukocytes. Chest X-ray film disclosed marked abnormal colon gas which located right subdiaphragma (Chilaiditi syndrome). Cerebrospinal fluid contained 12 cells/mm3, 99% lymphocytes; protein, 58.8 mg/dl; IgG, 6.8 mg/dl; HVA, 4.5 ng/ml (normal 41.8-44.6); 5-HIAA, 1.3 ng/ml (11.3-29.2); MHPG, 5.8 ng/ml (13.2-22.2).(ABSTRACT TRUNCATED AT 250 WORDS)

[Quantification of renal function with 99mTc-MAG3--quantification of tubular extraction rate using Bubeck's method].

99mTc-mercaptoacetyltriglycine (MAG3) is a new agent for dynamic renal scintigraphy. It provides not only superior quality of imaging to conventional agents such as 131I-orthoiodohippurate or 99mTc-demethylenetriaminepantaacetic acid but also quantification of renal function as do the latter agents. The aim of the present study was to evaluate the value of the tubular extraction rate (TER) using 99mTc-MAG3 calculated by Bubeck's method, a simple technique for quantifying renal function. In 31 patients with renal disorders, we compared the TER thus obtained with laboratory data, plasma paraaminohippurate clearance, effective renal plasma flow calculated by Tauxe's method, and plasma 99mTc-MAG3 clearance calculated according to the two-compartment model. TER was easily applicable in clinical settings, and showed close parallels with the other indexes of renal function. We believe, therefore, that it can serve as a useful parameter of renal function.