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Biomedical subjects

S C Liao

Publications and source records attributed to S C Liao.

At least 19 recordsLinked to original sources
PubMed2001

A missing data treatment for data mining applications in medical information systems.

To apply user-friendly, easily operated and accessible tools to handle missing data resulting from an auto-stored medical information system, these tools are applied to satisfy general users from different disciplines (i.e. statistics and machine-learning), followed by medical information system development. This study attempts to develop a new logic separation inference method applied to a database with a format like most real-world medical records containing many missing data and miscellaneous variables. It is expected that this method should have better performance than currently accessible methods. The newly developed logic separation inference method shows a classification power of 0.997 (elimination method is 1), which is better than the simple replacing method (replaced by mode shows 0.974). Both inference methods (mode and mean) have superior classification power to the simple replacing method. The missing data treatment processes introduced in this study can be completed on a MS Excel spreadsheet without any complicated calculation; therefore, they can satisfy general users. This new missing data treatment method is only applied up to 60% of the missing data (missing at random). However, when there is large amount of data, it is expected that this method also can be applied to a database missing more than 60%.

Humans↗
PubMed1999

Low dose desferrioxamine can improve erythropoiesis in iron-overload hemodialysis patients without side effects.

OBJECTIVE: Multiple blood transfusions were often required to treat anemia in uremia patients before the era of recombinant human erythropoietin (r-HuEPO). Iron overload thus frequently occurred in chronic hemodialysis patients. Desferrioxamine (DFO) is an effective chelating agent, which can remove excessive iron and can enhance erythropoiesis. Large dose DFO treatment is a therapy associated with the development of severe complications. In this study, a low dose DFO regime was used to treat iron overloaded hemodialysis patients. The efficacy and side effects of this regiment were evaluated. MATERIALS AND METHODS: Eight iron overloaded chronic hemodialysis patients were enrolled in this study. All patients received DFO 500 mg intravenously twice-a-week for eight months. Serum aluminum, transferrin saturation (TFS) and r-HuEPO requirement were recorded before and after DFO treatment. Serum ferritin and hematocrit (Hct) were measured before, during, and after the DFO withdrawal period. All patients were evaluated and followed closely during treatment. RESULTS: Changes in aluminum, TFS and r-HuEPO dosage were unremarkable (p > 0.05). Hct increased significantly after eight months of DFO treatment (from 25.3% to 27.0%, p < 0.05). Ferritin level was reduced by 43.2% at the end of treatment and an evident decline of ferritin was achieved after four months of treatment (2102 ng/mL to 1166 ng/mL, p < 0.05). All patients tolerated the treatment well and no complications were found. CONCLUSION: Low dose DFO can chelate iron effectively in chronic hemodialysis patients. This treatment can enhance erythropoiesis without adverse effects.

Anemia↗
PubMed1998

The significance of syphilis serology tests on long-term hemodialysis patients.

BACKGROUND: Syphilis is a sexually transmitted disease. Blood transfusion and blood contact are also routes of infection. Patients on long-term hemodialysis are at risk during their therapy. The aim of this study is to investigate the incidence of syphilis in hemodialysis patients, possible nosocomial infection and methods of treatment. MATERIALS AND METHODS: A total of 556 uremic patients on maintenance hemodialysis at our hospital on June 1996 were enrolled in the study. They all received syphilis screening tests. The rapid plasma reagin (RPR) test was used as the primary screening tests and Treponema pallidum hemagglutination assay (TPHA) test as the confirmation test. According to the test results, patients were classified into false and true-positive groups. The titer of both tests were recorded. The patients in the true-positive group were further divided into the untreated and treated group depending on whether they had already received treatment. The serial change of RPR test titer of the treated group was reviewed. RESULTS: Thirty-one patients (5.6%) had positive RPR test results and 10 patients (1.8%) had false-positive results. The titers of both RPR and TPHA tests were rather low in the positive groups. Most of the confirmed syphilis patients were asymptomatic and diagnosed serologically. In the treated group, the RPR test titer did not show significant decline and no seroconversion was noted after treatment. CONCLUSION: We observed that infectious syphilis patients exist in our hemodialysis unit and survey for this disease is necessary. The titers of both positive RPR and TPHA tests are low. Most diagnosed patients had latent syphilis, and serologic response to treatment is probably the same as in general population.

Aged↗
PubMed1998

Spontaneous cellulitis in adults with idiopathic nephrotic syndrome.

BACKGROUND: Susceptibility to infection is a common problem in a patient with nephrotic syndrome. The spontaneous cellulitis is not uncommon in pediatric patients with nephrotic syndrome, whereas there have been few cases reported in adults. In order to clarify the clinical course of this complication, we present 17 adult idiopathic nephrotic patients with spontaneous cellulitis. MATERIALS AND METHODS: A series of 17 adult idiopathic nephrotic patients with spontaneous cellulitis were retrospectively reviewed in Chang Gung Memorial Hospital, Kaohsiung from 1986 through 1996. We analyzed their physical conditions, clinical manifestations, and outcome. All patients received renal biopsies and had pathologic diagnoses. RESULTS: The medical records of 17 patients were collected, 12 men and 5 women, with ages ranging from 16 to 63 years (mean 29.5 years). The pathologic diagnoses of renal biopsies included minimal change disease (13/17), membranous glomerulonephritis (2/17), mesangioproliferative glomerulonephritis (1/17) and focal/segmental glomerulosclerosis (1/17). All patients had generalized edematous state. The clinical presentations of these patients were variable. The mean serum albumin and daily urinary protein excretion were 1.28+/-0.64 g/dl and 8.75+/-5.16 g, respectively. The results of blood cultures were E. coli (3/17), Gram-negative bacilli (1/17), Streptococcus viridans (1/17), Streptococcus pneumoniae (1/17) and no growth (11/17). All patients responded to antibiotic treatment except one patient who died due to overwhelming sepsis. CONCLUSION: The related factors of spontaneous cellulitis in patients with nephrotic syndrome are edematous skin, hypoalbuminemia, immunosuppressive drugs and defective immunity. Our patients had accordant conditions. The prognosis was good if diagnosis and treatment are made early.

Adolescent↗
PubMed1997

Real-time frequency domain temperature and oxygen sensor with a single optical fiber.

The combined excited-state phosphorescence life-times of an alexandrite crystal and platinum tetraphenylporphyrin Pt(TPP) in a single-fiber sensor are used to monitor temperature and oxygen concentration in the physiological range from 15-45 degrees C and 0-50% O2 with precision of 0.24 degree C and 0.15% O2 and accuracy of 0.28 degree C and 0.2% O2. A 500-micron cubic alexandrite crystal bound to the distal end of a 750-micron-diameter optical fiber core and the Pt(TPP) coated circumferentially with a length of 1 cm from the end of the same fiber are excited with pulsed super-bright blue LED light. This apparatus uses a 125-kHz sampler for data acquisition and frequency domain methods for signal processing. The instrument amplifies both the dc and ac components of the photomultiplier output and band limits the signal to 20 kHz. The fundamental frequency of the excitation is set to 488.3 Hz and the highest harmonic used is the 35th. This bandlimited signal is sampled and averaged over a few hundred cycles in the time domain. The frequency domain representation of the data is obtained by employing fast Fourier transform algorithms. The phase delay and the modulation ratio of each sampled harmonic are then computed. At least four log-spaced harmonic phases or modulations are averaged before decoding the two lifetimes of temperature and oxygen phosphorescent sensors. A component of zero lifetime is introduced to account for the excitation backscatter leakage through optical interference filters seen by the photodetector. Linear and second-order empirical polynomials are employed to compute the temperatures and oxygen concentrations from the inverse lifetimes. In the situation of constant oxygen concentration, the lifetime of Pt(TPP) changes with temperature but can be compensated using the measured temperature lifetime. The system drift is 0.24 degree C for the temperature measurement and 0.59% for the oxygen concentration measurement over 30 h of continuous operation. The instrumentation and methods allow for 6-s update times and 90-s full-response times.

Algorithms↗
PubMed1996

Sequencing analysis of cDNA clones encoding the American cockroach Cr-PI allergens. Homology with insect hemolymph proteins.

A previous article described the isolation of several lambdagt22A cDNA clones expressing the American cockroach (Periplaneta americana) Cr-PI allergens recognized by both human atopic IgE antibodies and anti-Cr-PI monoclonal antibodies (Wu, C. H., Lee, M. F., and Liao, S. C.(1995) J. Allergy Clin. Immunol. 96, 352-359). This article presents the nucleotide and deduced amino acid sequences of two cDNA clones encoding major allergens of P. americana. Clones C12 and C20 encode proteins of 685 and 631 amino acids with two potential N-glycosylation sites each. The predicted molecular weights for C12 and C20 cloned proteins are 79,300 and 75, 500 with isoelectric point values of 6.26 and 6.63, which are compatible with the determined sizes (Mr 78,000 and 72,000) and isoelectric point value (6.2) of the Cr-PI allergens of P. americana. A high degree of identity (69.1%), including several overlapped predicted central antigenic determinant residues, was found between two allergens. The anti-fusion protein antibody-based enzyme-linked immunosorbent assay was able to detect crude American cockroach extract, Cr-PI, recombinant proteins, and commercial cockroach extracts, which provides further evidence that two allergens share common antigen determinants. Recombinant allergens of clones C12 and C20 both showed 47.4% skin reactivities on 19 cockroach-sensitive asthmatic patients. Unexpectedly, although no sequence similarity was found to other known allergens, two aromatic amino acid-rich allergens were found to have a striking sequence identity to insect storage proteins (20.1-33.9%), insect juvenile hormone-suppressible proteins (30.9-36.4%), and arthropod hemocyanins (29.7-34.6%). Results suggested that two prominent allergens of P. americana are ancestrally related to these insect hemolymph proteins and represent a new group of proteins in the hemocyanin superfamily. These data will now facilitate epitope-mapping studies, and the recombinant allergens may be valuable for diagnostic and therapeutic purposes.

Adolescent↗
PubMed1996

Real time frequency domain fibreoptic temperature sensor using ruby crystals.

The excited state phosphorescence lifetime of ruby crystals is used to monitor temperature in the physiological range from 15 degrees to 45 degrees C with precision and accuracy less than 1 degree C, in real time. Precision of 0.1 degree C is attained with 3 min integration times. A 500 micron cubic ruby crystal bounded to the distal end of an optical fibre of similar core dimensions is excited with pulsed Ne-He laser light of about 9 microW average power. The instrument uses a sampler for data acquisition, and frequency domain methods for data fitting. The instrument amplifies the a.c. components of the detector output and band limits the signal to 800 Hz. The fundamental frequency of the excitation is set to 24.41 Hz to obtain 32 or less harmonics. This band-limited signal is sampled and averaged between 20 and 100 cycles to obtain temperature measurements in real time. The frequency domain representation of the data is obtained by employing fast Fourier transform algorithms. The phase delay and the modulation ratio, of each sampled harmonic, is then computed. Five to 32 values of the phase and modulation are averaged before computing the sensor lifetime. The technique is capable of measuring precise and accurate excited state lifetimes from subpicowatt luminescent signals in plastic optical fibres. A least squares fit yields the lifetimes of single exponentials. A component of zero lifetime is introduced to account for the backscatter excitation seen by the photodetector leaking through optical interference filters. The phosphorescence lifetimes measured reproducibly to about six parts in 1000, with a 2 s integration time, are used to monitor physiological temperature. Temperatures are computed employing empirical polynomials. The system drift is 3% over 5 h of continuous operation. The instrumentation and methods allow 2.7 s update times and 50 s full response times.

Biomedical Engineering↗
PubMed1996

Tetrodotoxin poisoning in Taiwan: an analysis of poison center data.

Tetrodotoxin (TTX) poisonings are not infrequently seen in Taiwan, and several outbreaks have been recorded by the Poison Control Center (PCC)-Taiwan during 1988-1995. However, their demographic data, clinical features, and medical outcome have not been reported. A retrospective study analyzed the PCC data of TTX poisonings. All patients reported to the PCC-Taiwan as TTX poisoning from July 1988 through December 1995 were included. Excluding 2 incidents, the diagnosis of TTX poisoning was documented by identification of puffer fish and/or by the analysis of TTX in it. Patient age, sex, season of poisoning, substances ingested, incubation period, presenting symptoms, recovery time, and clinical outcome were analyzed. A total of 20 incidents involved 52 patients. Males outnumbered females (52% vs 41%) with sex undetermined in 4 patients. Most incidents occurred in the spawning seasons of puffer fish, eg March to May. Puffer fish ingestion accounted for 18 incidents; ingestion of gastropod mollusks and Gobius criniger were responsible for the other 2 incidents. Following ingestion of puffer fish and other poisonous marine animals, most symptoms developed within 6 h with complete recovery usually in 24 h. Symptoms of TTX poisoning were similar as those previously reported; however, unusual features, such as hypertension (24%), pinpoint pupils (4%), bronchorrhea and facial flush (2%), were also seen. The mortality rate was 13.5%. The violent neurotoxin is present in puffer fish and occurs in other marine animals. Without adequate therapy, patients may have serious morbidity or even succumb. Careful identification of puffer fish and other poisonous marine animals, as well as proper treatment of TTX poisoning patients, are mandatory to successfully handle cases of TTX poisoning.

Aging↗
PubMed1996

Evaluating lead bioavailability data by means of a physiologically based lead kinetic model.

A method of bioavailability estimation is presented in which a physiologically based kinetic model of lead kinetics is fit simultaneously to blood and bone lead concentrations after a period of exposure to dietary lead. Optimization of the simultaneous fit, varying only fractional absorption, gives the best estimate of fractional bioavailability for each treatment group. The analysis was applied to data from three separate studies in which rats were fed for 30 consecutive days purified diets containing lead added as lead acetate, mine waste-contaminated test soils, or mine waste itself. Fractional absorption decreased as lead intake increased, regardless of the source of the lead; but the magnitude of this dose dependence was lead source-dependent. There were no differences in lead absorption by male and female rats when lead intake was expressed per unit body weight. Fractional absorption varied from 4 to 5%, at low exposure rates (1-2 mg lead/kg/day) when lead acetate was added to the diet, to 0.24% at a high exposure rate (24 mg/kg/day) when a mine waste-contaminated test soil was added to the diet. Comparison of the results of this analysis with the results of a more conventional analysis, in which the bone and blood lead concentrations were separately compared with bone and blood lead concentrations in rats given daily injections of lead acetate intravenously for 29 consecutive days, demonstrated that the standard analysis failed to reveal the dose dependence of fractional absorption.

Animal Feed↗
PubMed1996

[Clinical experience of automated double filtration plasmapheresis].

Double filtration plasmapheresis, one kind of fractionation plasmapheresis, was developed from membrane type plasmapheresis to remove only the pathogen and return the normal protein back to the patient. We started our automated double filtration plasmapheresis since December 1993. There were 13 patients who received one hundred treatments totally during one year period. And they are myasthenia gravis (8 patients); acute inflammatory demyelinating polyneuropathy (1 patient), multiple myeloma (1 patient); acquired factor VIII inhibitor (1 patient); autoimmune hemolytic anemia (1 patient); systemic lupus erythematous (1 patient). Technically double filtration plasmapheresis is easy to perform and time-saving. It also makes necessity of replacement fluid less frequent. Incidence of complication is rare, and this includes hypotension 2%, palpitation 1%, headache 1%, hemolysis 4%, air emboli 1%, high secondary pressure 2%, and no motality during our treatment. Clinical response is documented in cases of myasthenia gravis; acute inflammatory demyelinating polyneuropathy and acquired factor VIII inhibitor in our study. In conclusion, double filtration plasmapheresis is a time-saving, convenient, and safe therapeutic modality with rare complication. Because its effectiveness on limited kinds of diseases and costs relatively high price, thus plasmapheresis should be used in selected cases and treat aggressively if indicated.

Adolescent↗
PubMed1995

Light transmittance as an index of cell volume in hippocampal slices: optical differences of interfaced and submerged positions.

Light transmittance (T) in the CA1 region of hippocampal slices was measured during exposure to media of various osmolarities to determine the utility of optical measurements as an index of changes in cell volume. In slices positioned at the gas-liquid interface, hypo-osmotic medium consistently produced a decrease in T and hyperosmotic medium produced an increase in T. The magnitude of deltaT was graded as a function of the strength of osmotic change. All changes in T were reversible upon return to isosmotic medium. In contrast, osmotically induced changes in T in submerged slices were consistently opposite in direction to those observed in slices at the interface. The magnitude and direction of deltaT could be altered by systematic variation of the level of the bathing medium within the same chamber, indicating that both extrinsic optical properties of various interfaces, such as refraction and reflection, and intrinsic optical properties of the tissue contribute to the observed T. Spectral measurements eliminated the possibility that osmotically induced deltaT was the result of changes in light absorbance by intrinsic chromophores such as cytochromes or hemoglobin. The results show that measurements of deltaT can be a useful index of changes in cell volume in brain slices, provided that the level of the bath remains constant.

Animals↗
PubMed1995

Bioavailability of arsenic in soil and house dust impacted by smelter activities following oral administration in cynomolgus monkeys.

This study was conducted to determine the extent of arsenic (As) absorption from soil and house dust impacted by smelter activities near Anaconda, Montana. Female cynomolgus monkeys were given a single oral administration via gelatin capsules of soil (0.62 mg As/kg body wt) or house dust (0.26 mg As/kg body wt), or soluble sodium arsenate by the gavage or intravenous route of administration (0.62 mg As/kg body wt) in a crossover design with a minimum washout period of 14 days. Urine, feces, and cage rinse were collected at 24-hr intervals for 168 hr. Blood was collected at specified time points and area under the curves (AUCs) was determined. Arsenic concentrations for the first 120 hr, representing elimination of greater than 94% of the total administered dose for the three oral treatment groups, were < 0.021 to 4.68 micrograms/ml for the urine and < 0.24 to 31.1 micrograms/g for the feces. In general, peak concentrations of As in the urine and feces were obtained during the collection intervals of 0-24 and 24-72 hr, respectively. The main pathway for excretion of As for the intravenous and gavage groups was in the urine, whereas for the soil and dust groups, it was in the feces. Mean absolute percentage bioavailability values based on urinary excretion data were 68, 19, and 14% for the gavage, house dust, and soil treatments, respectively, after normalization of the intravenous As recovery data to 100%. Corresponding absolute bioavailability values based on blood were 91, 10, and 11%. The bioavailability of soil and house dust As relative to soluble As (by gavage) was between 10 and 30%, depending upon whether urinary or blood values were used. These findings suggest that risks associated with the ingestion of As in soil or dust will be reduced compared to ingestion of comparable quantities of As in drinking water.

Administration, Oral↗
PubMed1995

Isolation and preliminary characterization of cDNA encoding American cockroach allergens.

BACKGROUND: Two prominent proteins of 78 and 72 kd in Cr-PI have been found to be the major allergens of American cockroach (Periplaneta americana). METHODS: A lambda gt22A cDNA library generated from messenger RNA of American cockroach was packaged into Escherichia coli Y1090(r-) and initially screened with rabbit polyclonal antiserum raised to crude extract of American cockroach (CRa-A). RESULTS: Twenty-nine anti-CRa-A-positive clones were isolated, and 11 clones were recognized by rabbit anti-Cr-PI and reactive with IgE antibodies of atopic serum pool. Among these 11 clones, eight were recognized by murine anti-Cr-PI monoclonal antibodies. Four clones (C7, C8, C12, and C29) were found to contain inserts of 2.6 kilobases (kb), and clones C5 and C20 were found to contain inserts of 2.4 kb. The remaining clones (C13, C23, C25, C28, and C35) were found to contain inserts of 1.8, 1.6, 2.5, 1.7, and 0.9 kb, respectively. Clones C12, C20, C13, and C28 were selected, subcloned into the expression pET vectors, and used to transform, E. coli BL21(DE3). Immunoblot analyses of clones C12, C20, C13, and C28 with anti-Cr-PI monoclonal antibodies revealed fusion proteins with molecular weights of 78 and 50 kd, and 43 kd, 54 kd, and 46 kd, respectively. However, among those fusion proteins only those with molecular weights of 78, 72, 54, and 46 kd were able to bind human specific IgE antibodies. CONCLUSIONS: The cDNA clones are expected to code for the major and principal allergens of American cockroach, and recombinant allergens may therefore be valuable for diagnostic and therapeutic purposes.

Allergens↗
PubMed1994

Absolute bioavailability of lead acetate and mining waste lead in rats.

The primary purpose of this study was to generate data that could be used to determine the absolute bioavailability of lead using data from a previous study in which soil containing lead from mining waste was mixed with feed. Young male and female Sprague-Dawley rats (7-8 weeks of age, five/sex/group) were given either soluble lead acetate mixed in a purified diet (AIN-76) at three different dose levels (1, 25, and 250 ppm Pb for 30 consecutive days) or intravenously at doses of 0.02, 0.20, and 2.0 mg Pb/kg BW for 29 days. A control group (purified diet only) was also included. The intravenous groups were used to provide maximal absorption (lead presumed to be 100% bioavailable) and accumulation data for lead in blood, bone, and liver. The lead acetate groups were used to evaluate the comparability of the present study with a previous study that compared bioavailable lead from ingested soil and lead acetate. Group mean whole blood, bone and liver lead concentration values increased with increasing dose levels for all treatment groups. A linear relationship was observed between blood lead concentration and dose following intravenous administration of lead and this provided empirical support for using blood lead concentrations at supposed steady state (approximately 30 days) to compute the bioavailability of lead administered by different routes and from different sources. The absolute bioavailability values of mining waste lead in soil were low based on the results for all tissue types. Absolute bioavailability values for lead acetate in dosed feed for blood, bone, and liver were approximately 6-, 19-, and 20-fold greater, respectively, than mining waste lead. Based on the current design and test system used, the absolute bioavailability of mining waste lead in soil administered in feed was approximately 3% based on blood data and less than 1% based on bone and liver data. These data are consistent with the low solubility of the constituent lead mineral phases in Butte soils.

Administration, Oral↗
PubMed1994

Fabry's disease: clinical, pathologic and biochemical manifestations in two Chinese males.

Fabry's disease is a rare hereditary disease transmitted as an X-linked recessive trait with the primary metabolic defect of an enzyme alpha-galactosidase A, resulting in deposition of glycolipids (ceramide trihexoside) in various tissues, including the kidneys. Two sibling cases of Chinese adult male patients in a family with Fabry's disease were completely evaluated including the clinical, pathologic and biochemical studies. Both of the patients had the similar clinical manifestations such as telangiectases, proteinuria, acral pains, corneal opacities, tortuous renal vessels and recurrent fever. Chronic renal insufficiency was noted in Case 1, whereas Case 2 had normal renal function. Microscopic hematuria was noted in Case 1. In renal biopsy, LM showed foamy vacuolation of the glomerular visceral epithelial cells and EM showed widespread myelin bodies (Zebra bodies) in kidney tissues, most numerous in visceral epithelia in both cases. Those findings are diagnostic for Fabry's disease. The plasma activity of alpha-galactosidase of Case 1 was 0.8 and that of Case 2 was 1.0 (normal reference range: 8.5-18.5 nmol/hr/min). The plasma activity of alpha-galactosidase A of Case 1 was 0.4 and that of Case 2 was 0.8 (normal reference range: 7.9-16.9 nmol/hr/min). All the enzyme activities in both cases were much lower than those of normal subjects. In addition to clinical presentations, pathologic study and biochemical study with assays of plasma or serum activities of alpha-galactosidase and alpha-galactosidase A are important steps in the diagnosis of Fabry's disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Bioavailability of arsenic in soil impacted by smelter activities following oral administration in rabbits.

This study determined the extent of arsenic (As) absorption from soil from Anaconda, Montana. Prepubescent male and female SPF New Zealand White rabbits (5/sex/group) were given a single oral (capsule) administration of soil (3900 ppm As) at three different dose levels (0.2, 0.5, and 1.0 g of soil/kg, corresponding to 0.78, 1.95, and 3.9 mg As/kg, respectively). Standard groups included untreated controls, an intravenous sodium arsenate group (1.95 mg As/kg), and a gavage sodium arsenate group (1.95 mg As/kg). Urine, cage rinse, and feces were collected at 24-hr intervals for 5 days and were analyzed for total As concentration. Clinical signs, body weights, and food consumption for treated animals were similar to controls. Maximum As concentrations were obtained over the initial 24-hr collection interval. A dose-dependent delay in urinary As excretion, the major elimination pathway, was observed in the oral soil group compared to that in the gavage group. For the animals in the soil groups, approximately 80% of the administered As dose was eliminated in the feces compared to approximately 10 and 50% for the intravenous and oral gavage groups, respectively. The relative oral bioavailabilities (+/- SD) of As in the gavage and test soil groups based on comparison with excreta data from the intravenous group were approximately 50 +/- 5.7 and 24 +/- 3.2%, respectively (after normalization of intravenous group's As recovery data to 100%). These results indicated that As in the soil was probably in a less soluble and therefore a less absorbable form than sodium arsenate.

Absorption↗
PubMed1992

Relative bioavailability of lead from mining waste soil in rats.

The purposes of this study were to determine the extent of absorption of lead (Pb) in mining waste soil from Butte, Montana, and to investigate the effect of mining waste soil dose (g soil/day) on tissue lead concentrations. Young, 7- to 8-week-old male and female Sprague-Dawley rats (5/sex/group) were given mining waste soil that contained 810 or 3908 ppm lead mixed in a purified diet (AIN-76) at four different dose levels (0.2, 0.5, 2, and 5% dietary soil) for 30 consecutive days. Standard groups included untreated controls and dosed feed soluble lead acetate groups (1, 10, 25, 100, and 250 micrograms Pb/g feed). The test soil dose levels bracketed a pica child's soil exposure level and the lead acetate concentrations bracketed the test soil dose levels of lead. Liver, blood, and femur were analyzed for total lead concentration using graphite furnace atomic absorption spectroscopy. Clinical signs, body weight, food consumption, and liver weights for test soil and standard groups were similar to control. Tissue lead concentrations from test soil animals were significantly lower than the tissue concentrations for the lead acetate group. Relative percentage bioavailability values, based on lead acetate as the standard, were independent of the two different test soils, dose levels, and sex and were only slightly dependent on the tissue (blood > bone, liver). Mean relative percentage bioavailability values of lead in the Butte mining waste soil were 20% based on the blood data, 9% based on the bone data, and 8% based on the liver data. The results of this study will provide the information needed to determine the significance of lead exposure from Butte soils in assessing human health risks as part of the Superfund Remedial Investigation/Feasibility Study process.

Animals↗