Urinary Sediment Cells Research Articles

Detection of a Transcript Abnormality in mRNA of the SLC12A3 Gene Extracted From Urinary Sediment Cells of a Patient With Gitelman???s Syndrome

Detection of a Transcript Abnormality in mRNA of the SLC12A3 Gene Extracted From Urinary Sediment Cells of a Patient With Gitelman???s Syndrome

Presence, quantitation and characterization of JC virus in the urine of Italian immunocompetent subjects

Human polyomavirus JC (JCV) infects the worldwide population, remains latent in the kidney, and is excreted in the urine. A longitudinal study was performed in order to evaluate JCV excretion, to characterize molecularly the virus and to determine if its presence in urine is a consequence of viral reactivation or merely of epithelial squamous cell shedding. The presence of cellular sediment and the JCV genome were examined in 333 urine samples collected periodically for 3 months from 17 healthy subjects; molecular characterization, and quantitation of the virus were also undertaken. JCV DNA was detected in 40.2% of the samples, with a significant difference (P<0.001) observed between males and females. JCV shedding was independent of the presence of cellular sediment in every individual. JCV genotype 1 was the genome detected most frequently, while all of the amplified strains showed archetypal organization of the transcriptional control region (TCR). No clinical symptoms have been associated with JCV excretion and no microbial load was detected in the urine samples. The lack of correlation between JCV DNA detection and the presence of squamous cells in urine sediment indicates that viruria is regulated by the life cycle of JCV. Thus, the virus is eliminated as consequence of its reactivation.

Pre‐ and postnatal findings in trisomy 17 mosaicism

Trisomy 17 mosaicism is one of the rarest autosomal trisomies in humans. Thus far, only 23 cases have been described, most of them detected prenatally. In only five instances has mosaicism been demonstrated in lymphocytes and/or fibroblasts postnatally, and only in these have multiple congenital anomalies (MCA), facial dysmorphisms, and mental retardation been reported. Patients with trisomy 17 mosaicism at amniocentesis and a normal karyotype in blood and fibroblasts (n = 17) were always healthy. Here, we report on pre- and postnatal clinical, cytogenetic, molecular-cytogenetic, and molecular findings in four patients with trisomy 17 mosaicism. The first case was detected in cultured but not in short-term chorionic villi and amniocytes. Due to MCA on prenatal ultrasound examination the pregnancy was terminated. The second patient is a 13-month-old healthy boy, in whom low level trisomy 17 mosaicism was detected in cultured chorionic villi only. The third patient is a 2-year-old girl with growth retardation, developmental delay, MCA, and trisomy 17 mosaicism in amniocytes, fibroblasts, and placenta, but not in blood and buccal smear. The fourth patient is a 9-year-old boy with growth and mental retardation, sensoneurinal hearing loss, and MCA. Cytogenetic analyses showed trisomy 17 mosaicism in amniocytes, skin fibroblasts, and urinary sediment cells, whereas in blood and buccal smear a 46,XY karyotype was found. Molecular investigations in all four cases indicated biparental inheritance of chromosome 17. Formation of trisomy was most likely due to a maternal meiosis I error in Patient 1 and a postzygotic non-disjunction of the paternal chromosome 17 in Patient 4. Cerebellar malformations, reported in two cases from the literature and in two reported here may be a specific feature of trisomy 17 mosaicism. Since the aberration has rarely been reported in lymphocytes, chordocentesis is not indicated in prenatal diagnosis. Prenatal genetic counseling for trisomy 17 mosaicism in chorionic villi or amniocytes should consider that the clinical significance remains uncertain.

Multiplex Polymerase Chain Reaction for Microsatellite Analysis of Urine Sediment Cells: A Rapid and Inexpensive Method for Diagnosing and Monitoring Superficial Transitional Bladder Cell Carcinoma

Several urinary markers have been recently introduced in clinical practice for improving the noninvasive diagnosis of transitional cell carcinoma. Although microsatellite analysis must be considered the best method in terms of results, its cost and method time are unacceptable for daily use. We validated a more rapid and inexpensive method of determination using rapid DNA extraction and automatic multiplex polymerase chain reaction amplification. A total of 120 patients who presented consecutively to a urological office, including 73 with transitional cell carcinoma and 43 who served as controls, were selected for study. Microsatellite analysis was performed in the blood/urine pair using 3 multiplex polymerase chain reactions per patient. Urine sediment inflammatory cells were assessed by urine dipstick test. Ten microsatellite loci were investigated. Numerical data collected during electrophoresis of the amplified segment in an ABI Prism 310 Genetic Analyzer were used to calculate the cutoff for allelic imbalance. Method sensitivity, specificity, and positive and negative predictive values were calculated. A total of 66 patients had microsatellite analysis alterations in urine sediment, of whom 59 had transitional cell carcinoma, while 7 had other urological diseases. Test sensitivity and specificity were 80.8% and 85.1%, respectively. Statistical analysis did not indicate any significant influence of inflammatory status on microsatellite analysis diagnostic performance. In the control group the allelic imbalance on chromosome 9 was significantly lower than on other chromosomes (p = 0.0143). This could confirm that chromosome 9 has a specific role in transitional cell carcinoma. The multiplex microsatellite analysis method was low cost and not time-consuming. Multiplex microsatellite analysis is a noninvasive, rapid, inexpensive and reproducible method for screening for and monitoring superficial transitional cell carcinoma. It should be considered an alternative method to urinary cytology and it should also be considered in the presence of urine sediment inflammatory cells.

Recurrence of Fabry disease as a result of paternal germline mosaicism for α-galactosidase a gene mutation

We present two sisters with a severe form of Fabry disease, who both carry the same mutation in the alpha-galactosidase A (alpha-gal A) gene (Q330X). Each of the sisters developed renal failure in the third decade of life; the older sibling underwent renal transplantation at 40 years of age. The severe phenotype of the siblings correlates with results of the X-inactivation study: examination of methylation status in human androgene receptor (HUMARA) gene suggests preferential inactivation of the wild-type allele in both patients. Patients' parents had no symptoms of Fabry disease and were tested negative for the mutation Q330X in DNA isolated from peripheral leukocytes, mouth wash cells, and urinary sediment cells. Genotype analysis using DXS7424 marker showed paternal origin of the mutation. The father's sperm was then tested for presence of the mutation to examine the possibility of the germline mosaicism. Both mutant and wild-type alleles were found in DNA isolated from father's sperm. The apparent explanation of these findings is germline mosaicism due to mutation event during the embryonic development of sperm producing cells (spermatogonia). This is the first case of germline mosaicism in Fabry disease reported in the literature.

Hemorrhagic Cystitis in Children Undergoing Bone Marrow Transplantation: A Putative Role for Simian Virus 40

Late-onset hemorrhagic cystitis (HC) is a well-known severe complication of bone marrow transplantation (BMT), both in adults and in children. Protracted postengraftment HC is associated with graft-versus-host disease and viral infections, mainly caused by BK virus (BKV) or adenovirus (AV). This study investigated whether simian virus 40 (SV40) DNA sequences can be detected in specimens from pediatric patients affected by severe postengraftment HC. The clinical diagnosis of HC was made in 7 of 28 BMT children. DNA from peripheral blood mononuclear cells (PBMC) and urine sediment cells and supernatants was analyzed by polymerase chain reaction (PCR) for human cytomegalovirus (HCMV), AV, BKV, JC virus (JCV), and SV40. DNA filter hybridization and sequencing was carried out in SV40-positive samples. SV40 footprints were detected in two of seven cases of HC. Specific SV40 DNA sequences were detected by PCR and by filter hybridization both in urine and in PBMC samples at the HC onset and during the follow-up. The DNA sequencing proved that the amplicons belonged to the SV40 wild-type. Urine samples of the two HC cases tested negative by cell cultures, PCR, or both for HCMV, BKV, JCV, and AV. The detection of SV40 DNA sequences suggest that this simian polyomavirus could be involved, at least in some cases, in the HC occurring in children after BMT.

A preliminary evaluation of the interaction between urine specific gravity and leukocyte esterase results using Bayer Multistix® and the Clinitek® 500

Objectives To determine the sensitivity of the leukocyte esterase (LE) pad to predict microscopically quantified white blood cells in urine sediment and to assess the interaction of urine specific gravity (SG) on leukocyte esterase sensitivity. Methods Microscopic quantification of white blood cells in urine sediment was performed manually and automated chemical urinalysis was performed using the Bayer Clinitek® 500 and Multistix® 8 SG strips on 422 random urine specimens. Results The sensitivity of the leukocyte esterase pad to predict white blood cells in centrifuged urine was 58% (61/106). There was a weak but statistically significant negative correlation between SG and LE pad performance, r = −0.12, p < 0.05. Conclusions The 58% sensitivity of the Multistix® leukocyte esterase detection of white blood cells in urine sediment was consistent with previous reports. The negative correlation of specific gravity and leukocyte esterase provides partial explanation for the lack of sensitivity of the leukocyte esterase test.

Banking of Urine Sediments as DNA Source in Epidemiologic Studies

The Authors Respond: Thank you for the opportunity to respond to the concerns of Dr. van Noord 1 about our article in Epidemiology. 2 We agree that urine sediment may provide a source of nucleated cells that can be easily and noninvasively obtained from adults and that may prove to be a useful source of DNA for epidemiologic studies. Dr. van Noord cites at least seven published reports of studies in which urine sediment is used as a source of DNA for genotyping. 3–9 Of the studies cited, five systematically assessed the suitability of urine sediment as a source of DNA for genetic studies, 3–5,8,9 and two are epidemiologic studies that used urine specimens as a DNA source but did not systematically assess the suitability of these specimens. 6,7 We found an additional study that evaluated urine sediment as a source of DNA for genotyping, 10 and two studies that found urine to be a satisfactory source of DNA from animals in the wild. 11,12 However, when we compared evidence in the literature for the utility of two noninvasive DNA sources—buccal cells and cells from urine sediment—we found much less methodologic evidence available to validate the reliability or to document the optimal conditions for use of urine specimens. 2,9 Although DNA yield is quite variable for both types of specimen, we chose to discuss buccal cells and not urine sediment cells in our review because more information was available for buccal cell specimens. Two of the reports cited by Dr. van Noord state that urine may be a useful specimen in large epidemiologic studies “when blood samples cannot be obtained or have not been stored.”8,9 These reports show genotyping success rates of 89% for one locus 8 and 78% for six loci. 9 Additionally, we suspect that obtaining urine specimens suitable for DNA banking from infants is more difficult than obtaining buccal cells, but we could find no published comparison of these specimens to confirm our suspicion. In summary, we believe that urine specimens may prove to be suitable sources of DNA for large epidemiologic studies but that systematic studies should be done to compare urine specimens with specimens that have been more thoroughly evaluated. We appreciate Dr. van Noord’s raising this issue, and we hope that simple alternatives to blood specimens will continue to be explored and validated. Karen K. Steinberg Deborah Nickerson Michele Caggana Margaret Gallagher

Loss of chromosome 16 from renal epithelial cells in humans.

This work explores the notion that low-frequency, acquired aneuploidy may play a role in complex genetic traits such as essential hypertension. To this end, renal epithelial cells in urinary sediments and in renal cysts were examined by fluorescent in situ hybridization with DNA probes specific for the heterochromatic and centromere regions of chromosomes 16 and 1. Chromosome 16 was probed because it harbors variant genes causing monogenic hypertension. These genes have also been investigated for their role in essential hypertension. Chromosome 1 was also probed as an internal control. Higher proportions of renal epithelial cells in the urinary sediments showed monosomy of chromosome 16 than monosomy of chromosome 1 (P<0.001). We also observed in epithelial cells of renal cysts a preponderance of monosomy for chromosome 16 over monosomy for chromosome 1 (P<0.024). Low-frequency loss of heterozygosity that results from acquired monosomy of chromosome 16 and perhaps other chromosomes may contribute to expression of complex genetic traits such as essential hypertension, in which the diverse phenotypic manifestations are poorly understood.

Renal involvement in dogs with babesiosis.

Proteinuria, and renal tubular casts and epithelial cells in urine sediment, are commonly observed in both complicated and uncomplicated babesiosis, but do not necessarily reflect or predict renal failure. This study investigated the presence and degree of renal damage in canine babesiosis. Renal function and integrity were evaluated using serum urea and creatinine, serum electrolytes (sodium and potassium), fractional clearance of sodium (FcNa) and potassium (FcK), urine enzyme activity of gamma-glutamyl transpeptidase and alkaline phosphatase, urine protein:creatinine ratio, and urinalysis. One control group (n = 10) and 3 groups of babesiosis cases were studied: mild uncomplicated (n = 10), severe uncomplicated (n = 11), and complicated (n = 9). All babesiosis groups showed well-concentrated urine. Mean serum urea was elevated in the severe and complicated groups, and was significantly different from the control group. There was no statistically significant difference between the groups for creatinine, although the complicated group had a mean value above the normal reference range. Hypokalaemia was uncommon in all the groups. Hyperkalaemia was present in only 2 dogs in the complicated group. Marginal hyponatraemia was present in a minority of dogs in all groups. The serum electrolytes were not significantly different between groups. There was no overall elevation, nor any statistically significant difference in both the FcNa and FcK between the groups. Only 1 dog, in the complicated group, showed marked enzymuria. Proteinuria was a common finding and was significantly different between the severe and complicated groups and the control group. Some dogs in all groups had renal tubular epithelial cells in the urinary sediment, which increased in severity from the mild to the complicated groups and was significantly different from the control group. This study demonstrated that minimal renal damage occurs more often in canine babesiosis than significant damage or acute renal failure.

Detecting bladder cancer in the Chinese by microsatellite analysis: ethnic and etiologic considerations.

Microsatellite analysis of urine sediments has shown promise as a highly sensitive and specific technique for the detection of bladder cancer. However, most studies have been conducted in Western countries with Caucasian subjects. We explored the potential of microsatellite analysis for detecting bladder cancer in Chinese people. We performed microsatellite analysis of surgical specimens and urine sediment cells collected from Chinese patients with bladder tumors. Those microsatellite markers giving clearly readable patterns and showing susceptibility to alterations were used as a panel to detect primary tumors. A blinded study of additional patients with bladder cancer was performed to investigate the practical value of this panel for detecting bladder cancer. All statistical tests were two-sided. Thirty-eight bladder tumors and corresponding urine sediment specimens were initially screened for 60 microsatellite markers from 18 chromosomes. Nine markers, most of which were different from those that had been used for Western patients, with frequent alterations in the initial patients were selected for further analysis. In the subsequent blinded experiment, microsatellite alterations were observed in urine sediments from 22 (96%) of 23 patients with bladder cancer and from all three patients with inverted papilloma. None of the urine sediments from the one patient with bladder lipoma, from the one patient with neurofibroma, or from the 12 individuals without evidence of bladder tumor showed any microsatellite alterations. Microsatellite analysis of urine sediments could be a practical method for detecting bladder cancer in the Chinese. Our identification of different microsatellite markers highlights possible ethnic and etiologic disparities between the Chinese and Western bladder cancer patients.

Urine cytology in patients with urinary tract calculosis.

Urinary cytological examination was performed on 375 patients suffering from urolithiasis at the Department of Urology. University School of Medical Sciences, Bydgoszcz between 01.01.1991 and 31.12.1992. 189 were female (mean age: 47.5 years), 186 were male (mean age: 53.5 years). We found dysplastic cells in urinary sediments in 25.3% of patients before therapy and in 5.3% of patients after conservative or traditional operation and interventional therapy (ESWL. PCNL). Degenerated cells were found in 72% of patients before therapy and in 30.4% after therapy only. In our group neoplasmatical cells were not found. Inflammatory background was found in 44.5% before and in 21.9% after therapy, pyuria in 19.7% and 0.8% respectively. In urinary sediments we found concrements in 24% of patients before and 7.7% after therapy. However, 20 (51.3%) of 39 patients after interventional therapy (ESWL, PCNL) had concrements in urinary sediments. In conclusion, no abnormality was seen in 85.1% before therapy and in 31.2% after therapy. The significance of cytological examination in management of calculous diseases was discussed.

Clinical and genetic studies of CLCN5 mutations in Japanese families with Dent's disease

Dent's disease is an X-linked renal tubular disorder that is characterized by low molecular weight proteinuria, hypercalciuria, nephrolithiasis, and renal failure. The disease is caused by inactivation of a renal chloride channel gene, CLCN5, that encodes a 746-amino acid protein with 12 to 13 transmembrane domains. The Japanese variant of Dent's disease has been observed to be less severe, and we have investigated two unrelated Japanese families for CLCN5 mutations. Six patients from two unrelated families were studied. Leukocyte DNA from probands was used with CLCN5-specific primers for polymerase chain reaction (PCR) amplification of the coding region and exon-intron boundaries, and the DNA sequences of the products were determined to identify abnormalities in the gene. RNA extracted from the kidney, leukocytes, or urine sediments was used to characterize further the effects of the identified mutations. beta2-microglobulinuria was detected in five patients, hypercalciuria in two patients, nephrolithiasis in three patients (2 of whom were females), and one 51-year-old man had renal failure. Two novel CLCN5 mutations consisting of an a to g transition at the invariant ag acceptor splice site of intron 5 and an intragenic deletion that encompassed the region between intron 3 and intron 6 were identified. The acceptor splice site mutation led to the utilization of two alternative cryptic splice sites in exon 6 that resulted in a frameshift or skipping of the exon 6. The deletional mutation, which resulted in a loss of exons 4, 5, and 6, is predicted to lead to a loss of domains 1 through 4. Both mutations predict truncated chloride channels that are likely to result in a functional loss. The observations of renal failure in one male and nephrolithiasis in two females represent important new findings in this Japanese variant of Dent's disease that is associated with CLCN5 mutations. In addition, our study is the first to demonstrate the use of urinary sediment cells and renal tissue for the detection of CLCN5 transcript abnormalities. These results help to expand the spectrum of CLCN5 mutations associated with Dent's disease.

Effects of general anesthesia and surgery on renal function in healthy dogs.

To evaluate renal function in healthy dogs undergoing general anesthesia and ovariohysterectomy without concurrent IV administration of fluids. 35 healthy client-owned dogs. Dogs were medicated with promazine hydrochloride (0.05 mg/kg of body weight, SC) approximately 45 minutes before induction of anesthesia with thiopental sodium (10 to 15 mg/kg, IV). Anesthesia was maintained with 2% halothane in oxygen. Ovariohysterectomies were performed by senior veterinary students under the direct supervision of a veterinary surgeon. Renal function was assessed (serum urea and creatinine concentrations, fractional clearance of sodium, urine alkaline phosphatase [ALP] and gamma-glutamyltransferase [GGT] activities, urine specific gravity, and enumeration of renal tubular epithelial cells in urine sediment) prior to and 24 and 48 hours after surgery. Duration of general anesthesia ranged from 80 to 310 minutes. Urine specific gravity and ALP activity and serum urea and creatinine concentrations did not change over time. Fractional clearance of sodium decreased 24 and 48 hours after surgery, whereas urine GGT activity and the ratio of urine GGT activity to urine creatinine concentration increased 24 hours after surgery, compared with presurgery values. Renal tubular epithelial cells increased in number in urine sediment from 11 of 35 (31.4%) dogs and 5 of 35 (14.3%) dogs 24 and 48 hours after surgery, respectively. However, this increase was not clinically relevant. Intravenous administration of fluids to healthy dogs undergoing general anesthesia and elective surgery may not be necessary for maintenance of renal homeostasis.

DNA from urine sediment or buccal cells can be used for blood group molecular genotyping

Accurate blood group antigen typing of red blood cells with a positive direct antiglobulin test or from a recently transfused patient has been a long-standing problem. To overcome this problem, we evaluated the feasibility of using somatic cells as a source of DNA for molecular genotyping. Two sources of cells that could be obtained by noninvasive procedures were chosen for analysis: urine samples, which were already available in the clinical laboratory, and buccal epithelial cells collected with cotton wool swabs. DNA, prepared using a commercial kit, was subjected to polymerase chain reaction amplification and followed by digestion with the appropriate restriction enzyme. Genotyping was performed for three alleles encoded by polymorphic genes on three different chromosomes, namely KEL1/KEL2, JKA/JKB, and FYA/FYB. Genotyping results were compared to the results of typing performed on red blood cells using standard hemagglutination techniques. Results given by samples freshly collected from volunteer donors were concordant. Although results obtained with samples collected from hospital patients were initially not in agreement with the phenotyping results, adjustments to the test protocol resulted in concordance. DNA from blood, urine sediment, or buccal cells can be used for blood group molecular genotyping. Immunohematology 15;2:61–65.

A Method for Classifying Blood Cells in Urinary Sediments Using Neural Network

A Method for Classifying Blood Cells in Urinary Sediments Using Neural Network

A 4-week intravenous toxicity study of the active metabolite (NM394) of prulifloxacin (NM441) in rats followed by a 4-week recovery test

A repeated dose toxicity study of ( +/- )-6- fluoro-1-methyl-4-oxo-7-(1-piperazinyl)-4H- [1,3]thiazeto[3,2-a]quinoline-3-carboxylic acid (NM394), the active metabolite of a new antibacterial agent, prulifloxacin, was conducted in Sprague-Dawley rats. Male and female rats were given the test material intravenously for 4 weeks at doses of 0 (control), 3, 10 and 30 mg/kg. After discontinuation of the treatment, a 4-week recovery test was also conducted. There were no treatment-related effects on survival, clinical signs, body weight and food consumption. Ophthalmoscopic and hematologic examinations failed to show any abnormalities related to the treatment. Increased water consumption was observed in the 10 and 30 mg/kg groups. In these dose groups, increased urine volume and lowered urine specific gravity, and crystalline substance and small epithelial cells in urinary sediments were seen. Cloudy urine was also seen in the 30 mg/kg group. Blood chemical examination showed decreased gamma-globulin in the 10 and 30 mg/kg groups and increased BUN and creatinine in the 30 mg/kg group. Pathological changes caused by the treatment were as follows. In kidney, tubular nephrosis with crystalline substance was observed in the 10 and 30 mg/kg groups and its organ weight was increased in the 30 mg/kg group. Cecal weight was increased in the 30 mg/kg group. The above-mentioned changes were reversible except for decreased gamma-globulin. Plasma levels and urinary concentrations of the test material were increased in all dose groups with dose-related manner, whereby no sex differences were observed. No effects caused by the repeated dosing were seen in the plasma concentrations. Toxicological findings were not observed in the 3 mg/kg group. The results show that the NOAEL of NM394 is 3 mg/kg for 4-week repeated dose toxicity in rats.

Tumor-associated eosinophilia in interleukin-2-treated patients: evidence of toxic eosinophil degranulation on bladder cancer cells.

Blood eosinophilia in tumor patients treated with interleukin-2 (IL-2) is well known and is regarded as evidence of toxicity or as a side-effect [Lotze et al. (1986) Arch Surg 121:1373-1379; West et al. (1987) N Engl J Med 316:898-905]. We recently described a new local IL-2 approach to therapy for advanced bladder carcinoma that allows, for the first time, high-dose continuous administration of natural interleukin-2 (nIL-2) at the tumor site without side-effects [Huland and Huland (1989) Cancer Res 49:5469-5474]. Tumor-associated eosinophilia of up to 65% (i.e. eosinophils constituting 65% of leukocytes) was seen in four of five patients after treatment, but never before treatment or in untreated controls. Activated eosinophils were attached to bladder tumor cells. Local activation was seen only after natural IL-2 treatment and was determined by cytological criteria and by staining with monoclonal antibody (mAb) EG1 directed against all eosinophil granule proteins and mAb EG2 directed against the active secretory granule proteins of the eosinophils. Bladder cancer cells in urinary sediment also stained with these two mAbs, revealing active degranulation of eosinophils on bladder tumor cells. The number of eosinophils in blood increased, however, without signs of activation. These data constitute strong evidence that activated eosinophils in vivo are involved in the IL-2-induced antitumor response.

The direct early diagnosis of cystic fibrosis by the detection of the deltaF508 CFTR gene mutation in a prematurely delivered boy

The suspicion of prenatal meconium ileus syndrome was raised in a pregnancy in a family with no history of cystic fibrosis because of significantly higher maternal serum alpha-fetoprotein in the 16th and 19th week of gestation, dispersed areas with increased echogenity in the fetal abdomen, slight fetal ascites in the 24th-25th weeks of gestation, decreased amniotic fluid gamma-glutamyltranspeptidase (GGT) activity and alpha-fetoprotein level in the 25th-26th weeks, and normal 46,XY karotype of the fetus. The detection of a homozygous deltaF508 cystic fibrosis transmembrane regulator (CFTR) gene mutation, by means of PCR from a small amount of white blood cells and urine sediment cells, substantiated the diagnosis of cystic fibrosis in a prematurely delivered boy in the 28th week of gestation. The repeated sweat test was unsuccessful. The autopsy examination confirmed the diagnosis of cystic fibrosis. Fetal meconium ileus syndrome was complicated by peritonitis and by formation of a meconium pseudocyst. Direct PCR typing improves postnatal diagnostic possibilities in the early neonatal period in prematurely delivered babies when the sweat test is difficult to perform.

Tissue-binding affinity of Proteus mirabilis fimbriae in the human urinary tract

Binding characteristics of the two major fimbrial hemagglutinin types of uropathogenic Proteus mirabilis were determined in frozen sections of human kidney and in exfoliated uroepithelial cells. P. mirabilis 3087, which expresses the MR/P fimbriae, adhered avidly to the tubular epithelial cells of the kidney and also to the epithelial cells of urinary sediment. No adhesion to glomerular or peritubular elements of the kidney was detected. Indirect immunogold silver staining also showed that the purified MR/P fimbriae recognized the same kidney domains. Adhesion of strain 3087 to uroepithelial cells was completely inhibited by Fab fragments of antibodies against the purified MR/P fimbriae. A completely different tissue-binding pattern was exhibited by the MR/K fimbriae of P. mirabilis 2456. In the kidney, the MR/K fimbriae bound strongly to the Bowman's capsule of the glomeruli and to the tubular basement membranes. A weak binding to glomerular mesangium and tubular epithelial cells was also seen. Strain 2456 did not adhere to epithelial cells of urinary sediment. Analysis of normal human urine showed that it contains low-molecular-weight molecules capable of inhibiting the binding of the MR/P fimbriae; no urinary inhibitors could be detected for the MR/K fimbriae. Poor in vivo binding capacity to intact human uroepithelial cells may be an important factor in explaining the relatively low pathogenicity of P. mirabilis in healthy hosts.