The in vitro activity of beta-lactamase inhibitors in combination with cephalosporins against M. tuberculosis

Although there are reports that the addition of a beta-lactamase inhibitor to ampicillin or amoxicillin greatly improves their in vitro activity against M. tuberculosis, there are no written reports about the antituberculosis effects of beta-lactamase inhibitors in combination with cephalosporins against M. tuberculosis. In this report, we have determined the minimal inhibitory concentrations (MIC) of 5 cephalosporins with or without combination with beta-lactamase inhibitor against M. tuberculosis strains isolated from patients before antituberculosis treatment and checked the production of beta-lactamase by bacteria before this procedure. Four strains of M. tuberculosis were contaminated during the experiment, and all the other 16 strains hydrolyzed the nitrocefin disc, thus indicating a beta-lactamase producer. The MICs of cephalosporins alone against M. tuberculosis were 200-400 micrograms/ml for ceforanide, 100-400 micrograms/ml for cephapirin, 400-1600 micrograms/ml for cefamandole, 200-1600 micrograms/ml for cefotaxime, and 800-1600 micrograms/ml for ceftriaxone. After adding the equimolar concentrations of sulbactam, the MICs were reduced to 100-200 micrograms/ml for ceforanide, 12.5-100 micrograms/ml for cephapirin, 100-400 micrograms/ml for cefamandole, 25-200 micrograms/ml for cefotaxime, and 100-800 micrograms/ml for ceftriaxone. We concluded that sulbactam enhanced the antituberculosis effect of cephalosporins.

A case of shunt nephritis

Nephritis associated with a chronically infected ventriculoatrial shunt is known as shunt nephritis. A 6-year-old girl with prior history of a ventriculoatrial shunt presented complaining of fever and gross hematuria. Serum complement levels were decreased and a coagulase-negative S. epidermidis was cultured from her blood. The renal biopsy specimen showed features of membranoproliferative glomerulonephritis type I. Hydrocephalus was so severe that shunt removal was impossible. With antibiotic therapy, clinical symptoms and laboratory findings include complement levels were normalized although microscopic hematuria persisted. To our knowledge, this is the first case of shunt nephritis in Korea. In addition to the case report, a brief review of shunt nephritis has been added.

Bilateral primary pigmented nodular adrenocortical disease--a case of report describing a rare cause of Cushing's syndrome

A case of Cushing's syndrome due to bilateral pigmented nodular adrenal disease in a 35-year-old male is presented. The adrenals showed multiple, black, variable sized nodules. Histologically the cells contained lipofuscin and either had a clear cytoplasm or an eosinophilic cytoplasm with a prominent nucleus. Lymphocytic infiltration and fatty metaplasia within the nodules are two of the prominent histological features. There is extreme internodular atrophy which suggests that primary pigmented nodular adrenocortical disease is a non-adrenocorticotropic hormone dependent condition. Since the disorder appears to involve primarily the cortex of both adrenals, the treatment of choice is bilateral adrenalectomy followed by steroid replacement. The characteristic clinicopathological manifestations that separate this diagnosis from other types of adrenal disease are also discussed. This is the first reported case in Korea to be documented with the pertinent clinicopathological findings.

Prevalence of EBV RNA in sinonasal and Waldeyer's ring lymphomas

A high incidence of a T cell phenotype of sinonasal lymphomas in other Asian countries has been associated with a high incidence of Epstein Barr virus (EBV) infection. We analyzed 13 sinonasal and 18 Waldeyer's ring lymphomas for the prevalence of EBV encoded RNA (EBER) using a sensitive and specific in situ hybridization. In addition, we examined the relationship of histologic findings and immunophenotype as well as the location of the lymphomas to the presence of EBV. The EBER was detected in each of 12 sinonasal lymphomas with a T cell immunophenotype. One B cell sinonasal lymphoma was EBER negative. Four of 18 Waldeyer's ring lymphomas were positive for EBER, including two T cell lymphomas. Two of 16 B cell Waldeyer's ring lymphomas were EBER positive. Morphologically, 11 of 20 diffuse large cell lymphomas, 2 diffuse mixed small and large cell lymphomas, 2 of 4 immunoblastic lymphomas and 1 lymphoplasmacytic lymphoma were EBER positive. Four follicular large cell lymphomas were EBER negative. A characteristic angiocentric or angiodestructive pattern was found in most T cell lymphomas and EBER positive cases. These findings indicate that EBV infection is more strongly associated with the T cell immunophenotype, angiocentric pattern and sinonasal location of the lymphoma.

The expression of beta 1 integrin and intercellular adhesion molecule-1 on mesangial cells and its modulation in glomerulonephritis

OBJECTIVES

This study was performed to observe the effects of conditioned media (CM) of cultured mononuclear cells (MNC) on the expression of beta 1 integrin and intercellular adhesion molecule(ICAM)-1 on mesangial cells and the modulation by TGF-beta, TNF alpha, or hydroxyl radical Also these were examined in anti-Thy mesangial proliferative GN (MsPGN) or puromycin aminonucleoside nephrosis(PAN).

METHODS

The expression of beta 1 integrin and ICAM-1 on mesangial cells was examined by ELISA and the modulation by TGF-beta, TNF alpha, or hydroxyl radical was investigated by using neutralizing antibody and dimethylthiourea. [.OH] scavenger.

RESULTS

The CM of MNC from Control suppressed the beta 1 integrin expression and thymidine incorporation and increased ICAM-1 expression on mesangial cells, compared to media alone. Especially the significant increase in ICAM-1 expression was reversed by anti-TNF alpha antibody. beta 1 integrin expression on mesangial cells was higher by the addition of CM of MNC in MsPGN than in Control, which was prevented by anti-TGF beta antibody or dimethylthiourea. ICAM-1 expression was not different among groups. Thymidine incorporation by adding CM of MNC was lower in MsPGN and PAN, which was mitigated by anti-TGF beta and anti-TNF alpha. Thus the ratio of the expression of ICAM-1 to thymidine incorporation was higher in MsPGN and PAN.

CONCLUSION

The expression of beta 1 integrin and ICAM-1, and the thymidine incorporation on mesangial cells are directly regulated by MNC, maybe through factors such as TGF beta or TNF alpha. In MsPGN, the overexpression of beta 1 integrin induced by MNC through TGF beta or hydroxyl radical on day 3 may be related to the pathogenesis.

An interesting case of intersex: case report

Intersex is a rare problem. Ambiguous genitalia, a frequent presentation of intersex, is seldom due to true hermaphroditism. This case report describes the findings in such a rare case.

Primary localized amyloidosis of the bladder--a case report

Primary localized amyloidosis is a rare disease with an excellent prognosis in most cases. We report a case of primary localized amyloidosis of the bladder that was treated with transurethral resection.

Effects of pulmonary air embolism on discharge of slowly adapting pulmonary stretch receptors

Pulmonary air embolism (PAE) usually causes small-airway collapse. Local transpulmonary pressure (Ptr) is thought to be closely associated with the activity of slowly adapting pulmonary stretch receptors (SAPSRs). To test whether discharge of SAPSRs located distal to collapsed airways is closely related to the overall Ptr, we studied 65 SAPSRs in anesthetized paralyzed open-chest dogs that were ventilated at constant tidal volume and frequency. PAE increased both Ptr and total pulmonary resistance but decreased dynamic lung compliance. Three groups of SAPSRs were identified on the basis of their locations in intrapulmonary airways. Group I had 29 SAPSRs located in airways < 1 mm in diameter. Group II had 10 SAPSRs that were found in intrapulmonary airways between 1 and 2 mm in diameter. PAE decreased the activity of 31 of the 39 SAPSRs in these two groups. Their activity during PAE was not related to Ptr. The 26 SAPSRs in group III were in airways > 2 mm in diameter. PAE increased the peak firing rate of 18 of these receptors, and there was a close relationship between the discharge frequency of these SAPSRs and the Ptr during PAE. In groups I and II, the dissociation between Ptr and SAPSR activity during PAE may have been caused by peripheral airway collapse. Activity of central fibers was blocked at higher temperatures than activity of peripheral fibers. We suggest that the response of a SAPSR to PAE depends on the location of the receptor within the lungs, and we speculate that threshold and fiber type are also related to location.

Trace elements in hair of Blackfoot disease

Blackfoot disease is a peripheral vascular disease resulting in gangrene of the lower extremities. Though extensive epidemiological study has implicated that high arsenic content in artesian well water of the endemic area bears some important connection with the disease, the etiology of the disease is still unknown. In this study, attention is paid to multielement determination in order to find out whether the trace elements in hair of Blackfoot disease patients are different from those of the controls. Experimental results indicate that the concentrations of As and Se in hair of patients are significantly higher than those of the controls, but Ca and Zn are significantly lower than those of the controls. The possible connection of these elements with the etiology of the disease is discussed.

Meningioangiomatosis--a case report

Meningioangiomatosis is a rare benign hamartomatous lesion. We describe a case of meningioangiomatosis in an 18-year-old boy with a 15 year history of seizures. Computed tomography reveals an irregular calcification density along the right temporal gyrus. Microscopically, irregularly branched blood vessels, surrounded by a concentric arrangement of proliferating spindle cells, are extending into the gray matter from the meningeal surface. Ultrastructural and immunohistochemical examination failed to demonstrate features of meningothelial cell origin in this case. This is the first case of meningioangiomatosis published in Korea along with immunohistochemical and electron microscopic studies. The pathogenesis and previous reports of this lesion will be discussed.

[Heavy metals in traditional Chinese medicine: ba-pao-neu-hwang-san]

Heavy metal intoxication of newborn infants fed with "Ba-Pao-Neu-Hwang-San" has been reported every year by many hospitals in Taiwan. About nine years ago, the National Laboratories of Foods and Drugs of the Department of Health, Executive Yuan, received one case report of a five month old female infant who died as a result of long term feeding with "Ba-Pao-Neu-Hwang-San". The drug was found to have contained lead 44,000 ppm. Although this unfortunate incident was propagated by most newspapers, the prescription of this ancient Chinese medicinal preparation is still widely accepted by ordinary people. Herbal medicine doctors prefer complex mineral drugs as did their ancestors thousands of years ago. In the last two years, we have collected 5 samples of "Ba-Pao-Neu-Hwang-San" from different manufacturers and measured the concentration of 16 heavy metals (including Cadmium, Mercury, Arsenic, Lead, Chromium, Manganese, Selenium, Germanium, Nickel, Calcium, Magnesium, Aluminum, Iron, Copper, Zinc, and Vanadium) in these drugs with Inductively-Coupled Plasma Atomic Emission Spectrometry and Graphite Furnace Atomic Absorption Spectrometry. The result of our survey revealed that the first sample (from Tainan) contained mercury 52,800 ppm, the fourth (from Ping-tung) contained mercury 34,500 ppm, and the fifth (from Sin-chu) contained mercury 65,700 ppm. The mercurial contents of these samples were apparently too high to be a safe drug.

Outcome of 143 pregnancies conceived by assisted reproductive techniques

One hundred and forty-three pregnancies conceived by assisted reproductive techniques (ART) from October 1985 to June 1989 in the National University Hospital, Singapore, resulted in 66 deliveries and 89 babies. There were 27 (18.7%) biochemical pregnancies, 44 (30.7%) clinical miscarriages and 6 (4.2%) ectopic pregnancies when total pregnancies were considered. Of those who continued pregnancy to second trimester multiple births occurred in 20 (13.3%) patients. A high incidence of vaginal bleeding and hypertension in pregnancy was noted in 32 (48.5%) patients and 18 (27.3%) patients, respectively. Caesarean section was the method of delivery in 48.5% of patients. Twenty-six (29.2%) babies required admission to the neonatal intensive care unit. All babies except one set of twins delivered at 24 weeks of amenorrhoea survived. Fetal abnormality was noted in 2 cases.

[Survey of heavy metals in traditional Chinese medicinal preparations]

Traditional Chinese medicinal preparations are still widely used by natives in Taiwan. Some traditional Chinese medicine prepared with ancient formulas have been found to contain some heavy metals. There has been an occasional pediatric case admitted with heavy metal intoxication. In the last two years, we collected 11 ancient formula drug samples from the families of the patients. We detected the heavy metals with an inductively-coupled plasma atomic emission spectrometry and a graphite furnace atomic absorption spectrometry. The final result of our report reveals the problem of heavy metals in traditional Chinese medicinal preparations as being very serious.

A clinicopathologic study on the diffuse malignant lymphoma--a morphologic and immunophenotypic analysis in 62 patients at Harbor-UCLA Medical Center

In order to compare the prognoses of patients with diffuse malignant lymphomas on the basis of histology and immunophenotypes, we retrospectively studied 62 cases of diffuse lymphoma arising in lymph nodes. We also evaluated the reactivity patterns of monoclonal antibodies (MoAb) LN1, LN2 and LN3 to determine the criteria for making a differential diagnosis in B cell lymphomas. The immunologic phenotypes were determined by the avidin biotin peroxidase complex method, using frozen or paraffin fixed tissues. The majority (66.3%) were B cell with the remaining 20.9% being T cell and 12.9% were non-B, non-T cell lineage. Immunological heterogeneity was found especially in the mixed small and large cell and the immunoblastic lymphomas. There was no significant difference between B- and T-cell lymphomas with respect to survival and death (P > 0.05). Histologically 79% (49/62) of the lymphoma was large cell and 21% (13/62), small cell lymphoma. There was a difference in prognosis between low, intermediate and high-grade of lymphomas. However there were no significant differences among the subtypes of the diffuse aggressive lymphomas. Factors associated with poor prognosis were advanced stages (P < 0.025) and histology of the malignant lymphomas. MoAb LN1, LN2 and LN3 gave positive staining in 83.3%, 91.7% and 60% of B cell lymphomas, respectively. The most common phenotypic pattern in B cell lymphomas was LN1+, LN2+, LN3+/-, suggestive of follicular center cell origin. As a panel, phenotypic patterns of MoAb LN1, LN2 and LN3 may be useful in differentiation of follicular center cell lymphoma from others.

[Morphological study of reticulo-epithelial cells in atrophic thymus]

Anti-keratin and PAP immunohistochemical reaction on atrophic thymus collected from 97 autopsies were studied. Among them, 61 cases belonged to the severs type, whose reticulo-epithelial cells were falling into 4 types: the normal type, the centrally focused type, the diffused type and the depletive type. In 37 out of 61 cases, the reticulo-epithelial cells showed proliferation, especially in the medullary zone. All of 7 cases known as physiological involutional thymus turned to depletive type. 11 cases of atrophic thymus studied by scanning electron microscopy had been classified morphologically into 3 patterns, namely: the reticular form, the honey-combed form and the depletive form respectively.

Serum sialyl stage-specific embryonic antigen levels in adenocarcinoma of the lung

The serum levels of sialyl stage-specific embryonic antigen (SSEA-1) in 67 patients with adenocarcinoma of the lung were studied to assess their values for diagnosis. A solid-phase immunoradiometric sandwich assay with an FH6 monoclonal antibody was used. Another 49 healthy adults, 52 patients with benign pulmonary diseases, and 142 lung cancer cases with cell types other than adenocarcinoma were evaluated for comparison. The mean (+/- S.D.) levels (U/mL) for adenocarcinoma of the lung, lung cancer other than adenocarcinoma, benign pulmonary diseases and normal subjects were 182.9 +/- 309.7, 53.5 +/- 22.6, 38.9 +/- 17.1 and 30.5 +/- 6.5, respectively. The mean serum sialyl SSEA-1 level was significantly higher in adenocarcinoma of the lung, compared with lung cancer other than adenocarcinoma (p < 0.001), benign pulmonary diseases (p < 0.001), or normal subjects (p < 0.001). For late stage (Stages III and IV, n = 58) adenocarcinoma of the lung, the mean (+/- S.D.) serum sialyl SSEA-1 level (204.3 +/- 327.6 U/mL) was significantly higher than that of earlier stage (Stages I and II, n = 9) adenocarcinoma of the lung (39.9 +/- 19.3), p < 0.001. There was no statistical difference among the mean serum levels of various histologic types of lung cancer other than adenocarcinoma (p > 0.05). In the lower range of values, considerable overlap existed between adenocarcinoma of the lung and lung cancer other than adenocarcinoma. However, very high sialyl SSEA-1 levels (> 140 U/mL) were only encountered in late stage adenocarcinoma of the lung (22/58).(ABSTRACT TRUNCATED AT 250 WORDS)

Multiple lymphomatous polyposis of the gastrointestinal tract--a report of two cases with immunohistochemical studies

We describe two cases of multiple lymphomatous polyposis in the gastrointestinal tract from the esophagus to the rectum. Clinical findings, histopathologic and immunohistochemical findings in paraffin embedded tissue are discussed. It is important to recognize this rare form of gastrointestinal lymphoma because of the prognostic and therapeutic implications.

[Estrogen receptor in female lung carcinoma]

80 cases of female lung carcinoma were assayed with avidin-biotin complex method for estrogen receptor (ER) and 73.8% cases revealed positive reaction. The 3 expressive types were cytoplasmic, all cellular and nuclear. There were no correlations between ER content and age, blood type, histologic types, size of tumor and metastasis of regional lymph nodes, but obvious correlations between ER content and prognosis. The 5 year survival rate in ER negative patients (72.7%) was greatly higher than in positive patients (8.8%) (P < 0.01). All had better prognosis in ER negative patients above and below 50-year groups.

Giant cell tumor of the scapula associated with secondary aneurysmal bone cyst

Giant cell tumors are distinctive neoplasms characterized by a profusion of multinucleate giant cells scattered throughout a stroma of mononuclear cells. Most giant cell tumors are found at the epiphyses of long bones, especially around the knee joint. Flat bone involvement is rare. However, a case of giant cell tumor with secondary aneurysmal bone cyst was encountered at the scapula of a 25-year-old man. Since the occurrence of a giant cell tumor with secondary aneurysmal bone cyst on flat bones (i.e., the scapula) is extremely rare, the above-mentioned case is worthy of reporting.

Retroperitoneal teratoma with predominance of nephroblastic elements--a case report

The morphological features of a retroperitoneal teratoma in a 10-month-old girl are reported. Unlike the usual pattern of the teratoma, this tumor was composed predominantly of nephroblastomatous tissue. Histologically, glomeruloid and tubular structures were identified in nests of undifferentiated blastemal elements. Hyaline cartilage, adipose tissue, glial tissue and glands lined by mucin-secreting columnar epithelium were minor elements. A focal cystic structure lined by thin flattened epithelium was also noted. Retroperitoneal teratoma with predominance of nephroblastic elements is of interest not only because of its rarity but also because it needs to be differentiated from extrarenal Wilms' tumor, since both of these tumors have different origins.

Nasal hemangiopericytoma--a case report

A case of rare intranasal hemangiopericytoma in a 68-year-old male was reported with typical histological and ultrastructural findings. The lesion clinically resembled a nasal polyp. The experience in the present case raised the need for differential diagnoses of vascularised spindle cell tumors and of traditional hemangiopericytoma in soft tissue.

Symptomatic subependymoma--a case report

Subependymoma is a rare, slow-growing, benign noninvasive tumor of the central nervous system that may be located in the fourth ventricle, the septum pellucidum, the third and the lateral ventricles, the aqueduct, and the proximal spinal cord. Symptoms, if any, usually result either from direct compression of the brain stem or from acute hydrocephalus due to occlusion of the foramen of Monro or aqueduct of Sylvius. In this report, we describe a case of subependymoma of the lateral ventricle with headache in a young female patient. This is the first reported case subependymoma in Korea that was documented along with Magnetic resonance image.

Effect of wet decomposition methods on the determination of cobalt, copper, selenium, and zinc in biological samples using electrophoresis

A method combining radiotracer techniques with paper electrophoresis to investigate the optimal decomposition conditions for cobalt, copper, selenium, and zinc in rat liver samples is described. After oral and intraperitoneal administration of the respective nuclides of 60Co, 64Cu, 75Se, and 65Zn solutions, the livers of the tested rats are removed and decomposed with a nitric and sulfuric acid mixture. The completeness of decomposition is investigated by measuring the respective radionuclide-containing species in the decomposed samples by electrophoretic analysis. The results indicate that the Co- and Se-containing liver samples are more easily decomposed than those containing Cu and Zn under the specific conditions. The same decomposition effects are observed for ingested radioisotopes as for intraperitoneally injected ones. The possible connection of decomposition with the analytical error is discussed.

Instrumental neutron activation analysis of gallstones

Four kinds of gallstones from 40 patients have been analyzed for the presence of a total of 18 elements by instrumental neutron activation analysis. Of these elements, Ca, Mg, Fe, Co, Zn, Na, and Cl are found in the core of all types of stones. The differences in elemental composition of the various types of stones as well as the differences in the cross-sectional layers of stones are statistically evaluated.

So-called sclerosing hemangioma of the lung--two cases report with ultrastructural study

Sclerosing hemangiomas of the lung are benign neoplasms of uncertain histogenesis. We analysed two cases of sclerosing hemangiomas of the lung with histochemistry and electron microscopy. They had a variegated histologic appearance characterized by an admixture of solid, hemorrhagic, papillary and sclerotic lesions. Characteristic uniform round cells, unique to this tumor, were found within the stroma in all lesions. In the electron microscopic examination, we found Weibel-Palade bodies like small bodies in the tumor cells. We suspect hypothesis originating in the endothelial cell can not be completely excluded yet. Sclerosing hemangioma is a distinct clinicopathologic entity and should be distinguished from other benign neoplasms or inflammatory lesions of the lung.

Nonparametric confidence interval estimators for heritability and expected selection response

Statistical methods have not been described for comparing estimates of family-mean heritability (H) or expected selection response (R), nor have consistently valid methods been described for estimating R intervals. Nonparametric methods, e.g., delete-one jackknifing, may be used to estimate variances, intervals, and hypothesis test statistics in estimation problems where parametric methods are unsuitable, nonrobust, or undefinable. Our objective was to evaluate normal-approximation jackknife interval estimators for H and R using Monte Carlo simulation. Simulations were done using normally distributed within-family effects and normally, uniformly, and exponentially distributed between-family effects. Realized coverage probabilities for jackknife interval (2) and parametric interval (5) for H were not significantly different from stated probabilities when between-family effects were normally distributed. Coverages for jackknife intervals (3) and (4) for R were not significantly different from stated coverages when between-family effects were normally distributed. Coverages for interval (3) for R were occasionally significantly less than stated when between-family effects were uniformly or exponentially distributed. Coverages for interval (2) for H were occasionally significantly less than stated when between-family effects were exponentially distributed. Thus, intervals (3) and (4) for R and (2) for H were robust. Means of analysis of variance estimates of R were often significantly less than parametric values when the number of families evaluated was 60 or less. Means of analysis of variance estimates of H were consistently significantly less than parametric values. Means of jackknife estimates of H calculated from log transformed point estimates and R calculated from untransformed or log transformed point estimates were not significantly different from parametric values. Thus, jackknife estimators of H and R were unbiased. Delete-one jackknifing is a robust, versatile, and effective statistical method when applied to estimation problems involving variance functions. Jackknifing is especially valuable in hypothesis test estimation problems where the objective is comparing estimates from different populations.

Arsenic, selenium, and zinc in patients with Blackfoot disease

Blackfoot disease is a peripheral vascular disease resulting in gangrene of the lower extremities. Extensive epidemiological study implicates that high arsenic content in artesian well water is the responsible causal factor of the disease. In the present study the concentrations of arsenic, selenium, and zinc in the body fluids and hair of patients with Blackfoot disease, in comparison to age- and sex-matched normal controls, are investigated. Two analytical techniques that include atomic absorption spectrometry and neutron activation analysis were used for the analysis of urine, serum, hair, and whole blood. The analytical results indicate that hair arsenic of the patients is significantly higher than that of the controls, but still below the critical value of 1 microgram/g. In addition, the patients showed significantly lower concentrations of Se and Zn in the urine and blood than the normal controls. The possible connection of these elements with the etiology of the disease is discussed.

Determination of major, minor and trace elements in urinary stones by neutron activation analysis

In five kinds of human urinary stones 18 elements have been identified by instrumental neutron activation analysis (INAA). From the results it may be concluded that calcium is the most important initiating cation, magnesium is the second most significant one, and Na, Cl, Sr, Zn, Fe, Br and Co may also play an important role in the stone formation. The results indicate also that ions like Ca, Br and Cu are easily incorporated into the nucleus to form a urate stone; Mg and Sr, into the nucleus to form a magnesium ammonium phosphate stone; and Zn, into the nucleus to form a calcium oxalate combined with apatite stone. The differences in elemental composition among the different kinds of stones as well as across the layers of stones are statistically evaluated.

Arsenic concentration in the urine of patients with Blackfoot disease and Bowen's disease

Extensive epidemiological study implicates that high arsenic content in artesian well water is the causal factor responsible for Blackfoot disease. We determine the arsenic concentration in urine samples of patients with Blackfoot and Bowen's diseases and examine whether there exists any discrepancy of urinary arsenic concentrations among patients and the normal population. The analyses were made by hydride atomic absorption spectrophotometry (AAS) and the analytical reliability of the method was checked with a standard urine sample (ORTHO Bi-Level Urine Metal Control). The results show that the mean urinary arsenic concentration in 100 healthy adults is 63.4±29.7 μg/L, and those means for 23 and 11 patients with Blackfoot disease and Bowen's disease are 75.7±39.1 μg/L (P vs controls >0.05) and 201±58 μg/L (P vs controls <0.001), respectively. From the analytical results obtained, we cannot conclude that urinary arsenic is associated with Blackfoot disease, as was disclosed from the epidemiological studies. However, urinary arsenic concentrations are possibly very closely associated with Bowen's disease.