Identification of genetically aberrant cell lineages in Wilms' tumors

Most Wilms' tumors contain several predominant cell types, of which a primitive blastemal population is often the most prominent. Other typical components include undifferentiated mesenchymal and epithelial cells, but it has not been demonstrated that these components are neoplastic. We used a combined cytogenetic and fluorescence in situ hybridization approach to determine the clonal relationship of different cell populations within six Wilms' tumors. Clonal numerical chromosome aberrations in three Wilms' tumors were found in blastemal cells, but not in mesenchymal cells. Loss of one WT1 allele in two other tumors was detected in both blastemal and mesenchymal cells. Tetrasomy 18 in a sixth case was observed in mesenchymal and epithelial cells; blastemal cells could not be evaluated in this tumor. These findings demonstrate that mesenchymal and epithelial cells in some Wilms' tumors are neoplastic. Different histologic components in some Wilms' tumors derive from a single chromosomally aberrant ancestor which is most likely to be the primitive blastemal cell.

The effect of obesity on fibrinolytic activity and plasma lipoprotein (a) levels in patients with type 2 diabetes mellitus in Korea

To determine whether previously reported abnormalities in fibrinolytic activity and plasma lipoprotein (a) levels could reflect obesity rather than diabetes per se, plasma concentrations of tissue-type plasminogen activator (t-PA), type 1 plasminogen activator inhibitor (PAI-1), and lipoprotein (a) (Lp (a)) were investigated in sixty-four type 2 diabetic patients (56.1 +/- 9.5 years; body mass index, 24.6 +/- 3.3 kg/m2) and thirty-two control subjects (57.9 +/- 8.9 years; body mass index, 24.6 +/- 3.4 kg/m2). Both the plasma t-PA and PAI-1 antigen levels were similar between the diabetic group (10.6 +/- 3.8 ng/ml; 27.7 +/- 11.6 ng/ml) and the control group (12.2 +/- 3.5 ng/ml; 27.7 +/- 9.6 ng/ml). The PAI-1 levels were evenly distributed from 5.93 to 52.7 ng/ml in diabetic patients. The difference of Lp (a) levels between the two groups was negligible (the diabetic group, median 11 mg/dl (range 0-72 mg/dl); the control group, median 13 mg/dl (range 0-55 mg/dl)). Significant correlations between PAI-1 levels and body mass index (BMI) were observed in both groups. In the diabetic group, PAI-1 levels also correlated with fasting C-peptide levels (r = 0.54, P < 0.01) and serum triglyceride levels (r = 0.28, P < 0.05). However, we could not find a significant association between either t-PA or PAI-1 levels and Lp (a) levels in the diabetic and control groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Reconstruction of cryptotia using a skin graft

Many surgical methods have been reported for the reconstruction of cryptotia. We have devised a new modified method for surgical correction of cryptotia that uses a skin graft from the retroauricular region, and have treated 15 ears of 14 patients using this method. The method is described and cases are illustrated.

The mechanism of antiproliferative effect of desferrioxamine on human hepatoma cell lines

We investigated the effect of desferrioxamine (DFO), an iron chelator, on the DNA synthesis and the cell cycle of cultured hepatoma cells. Using Hep 3B cells as the hepatoma cell lines, DNA synthesis was measured by [3H] thymidine incorporation, and the cell cycle analysis was performed by flow cytometry including bivariate DNA/BrdU analysis. [3H] thymidine uptake was decreased by DFO in a dose dependent manner. The proportion of S phase cells increased and that of G0/G1 phase cells decreased after the addition of DFO in the culture media in a dose dependent manner up to 20 micrograms/ml of DFO. The S phase duration of the exponentially proliferating Hep 3B cells was 9.9 hours when cultured without DFO, but it was markedly prolonged (54.1 hours) after the addition of 20 micrograms/ml of DFO. After removal of DFO from the culture media following 24 hours of incubation with 20 micrograms/ml of DFO, a sequential increase from early through mid and late-S to G2/M phase was observed. In conclusion, the antiproliferative effect of DFO on cultured human hepatoma cell lines was caused by the inhibition of DNA synthesis which was related to a block in the early-mid S interface or mid S phase of the cell cycle.

Cloning of Pseudomonas fluorescens carboxylesterase gene and characterization of its product expressed in Escherichia coli

A gene (estC) coding for an esterase (esterase III) of Pseudomonas fluorescens was cloned into Escherichia coli JM83. DNA sequencing showed a single open reading frame with GTG as a translation initiation codon for esterase III. This was confirmed by N-terminal amino acid sequence analysis of the purified esterase III protein from an E. coli clone. The promoter sequence and a potential Shine-Dalgarno sequence were followed by the coding sequence of the estC gene. The amino acid sequence deduced from the nucleotide sequence contains the consensus active site sequence, G-X-S-X-G, of serine esterase. The esterase III expressed in an E. coli clone was purified by ion-exchange chromatography and gel filtration. The native form of the enzyme was a monomer with a molecular weight of 41,000. The results of substrate specificity and the inhibitor studies suggest that this enzyme is a carboxylesterase (EC 3.1.1.1) and a serine residue is present at the active site of the enzyme.

Multiple myeloma presenting as a testicular mass

Primary testicular plasmacytoma is extremely rare and only a few cases have been reported. Testicular involvement in the course of multiple myeloma is just as rare and it implies a poor prognosis, expressing an acceleration of the malignant process. We present the case of a patient with multiple myeloma presenting as a testicular mass. The literature is reviewed and testicular involvement in plasma cell neoplasms is discussed.

Motion of model leukocytes near a wall in simple shear flow

Receptor-mediated cell adhesion to surfaces depends on the motion of the cell prior to adhesion. We studied the hydrodynamic behavior of cells near a wall in simple shear flow using a model leukocyte system that we have also used extensively in cell-substrate adhesion studies. Specifically, we measured the velocity of rat basophilic leukemia (RBL) cells near a surface in a parallel-plate flow chamber and compared it to the motion of polystyrene beads and glutaraldehyde-fixed RBL cells. We found that RBL cells (13 microns diameter) travel 25% faster than polystyrene beads of 14.5 microns diameter for a wide range of shear rates (20-180 s-1); this suggests that RBL cells would travel 39% faster than polystyrene beads of equivalent size. Glutaraldehyde-fixed RBL cells travel at a velocity between those of live cells and 14.5-microns beads. These differences in velocities have been observed over both polyacrylamide gel and glass substrates. Application of a theory for hard sphere motion near a wall in simple shear flow at low Reynolds number [Goldman, A.J.; Cox, R.G.; Brenner, H. Chem. Eng. Sci. 1967b, 22, 653-660] to our measured cell velocities suggests that cells are separated from the wall by > or = 550 nm. Such large separation distances have also been predicted by others who have used hard sphere theory to analyze the effect of shear flow on cell motion near walls. However, the extensive receptor-mediated cell adhesion seen in these systems is inconsistent with these separation distances, which are approximately 30 times greater than the distance required for receptor-ligand contact. Instead, we propose that, because of cell deformability and cell surface roughness, cells remain within a separation distance that allows for molecular contact while they travel faster than the hard sphere theory predicts. Therefore, the theory of Goldman and co-workers, while adequate for hard sphere motion, is likely not accurate for cellular motion.

WT1-mediated growth suppression of Wilms tumor cells expressing a WT1 splicing variant

A human Wilms tumor cell line (RM1) was developed to test the tumor suppressor activity of WT1, a zinc finger transcription factor that is expressed in the developing human kidney and is mutationally inactivated in a subset of Wilms tumors. Transfection of each of four wild-type WT1 isoforms suppressed the growth of RM1 cells. The endogenous WT1 transcript in these cells was devoid of exon 2 sequences, a splicing alteration that was also detected in varying amounts in all Wilms tumors tested but not in normal kidney. Production of this abnormal transcript, which encodes a functionally altered protein, may represent a distinct mechanism for inactivating WT1 in Wilms tumors.

Tyrosine phosphorylation of Ras GTPase-activating protein stabilizes its association with p62 at membranes of v-Src transformed cells

Ras GTPase-activating protein (GAP) regulates the activity of Ras proteins, which have key roles in signal transduction pathways downstream of oncogenic and receptor tyrosine kinases. Previous studies indicated that Tyr-457 of bovine GAP (Tyr-460 of human GAP) is the major site of phosphorylation by viral Src (v-Src) kinase and epidermal growth factor receptor. The finding that Tyr-457 in GAP is located immediately adjacent to Src homology 2 (SH2) and 3 (SH3) domains led us to investigate the possibility that this specific phosphorylation regulates protein-protein interactions involving GAP. For this purpose, we constructed a full-length GAP mutant containing a substitution of Phe-457 in place of Tyr-457. Both wild-type GAP and mutant GAPF457 were tagged with the KT3 epitope at the carboxyl terminus and were expressed in v-Src transformed rat fibroblasts. In vivo phosphorylation analyses established that GAPF457 was weakly phosphorylated on tyrosine and, as expected, lacked the phosphopeptide containing Tyr-457. Analysis of GAP-associated proteins in anti-KT3 immunoprecipitates showed that GAP stably associated with two major phosphoproteins, p62 and p190, which have been previously described. Significantly, association of p62 with GAPF457 was reduced approximately 3-fold compared with wild-type GAP. Subcellular fractionation experiments further demonstrated that Tyr-457 phosphorylation of GAP stabilized its association with p62 at cell membranes. Based on these findings, we propose that one role of tyrosine phosphorylation in GAP is to enhance its association with p62 at membranes, which in turn may contribute to regulation of Ras signal transduction pathways.

Inactivation of WT1 in nephrogenic rests, genetic precursors to Wilms' tumour

Nephrogenic rests consist of foci of primitive renal cells, typically microscopic, that are found within the normal kidney tissue of children with Wilms' tumour. To study the relationship between nephrogenic rests and the associated tumours, we screened these lesions for mutations in the 11p13 Wilms' tumour suppressor gene, WT1. In two cases in which the Wilms' tumour contained a somatic WT1 mutation, the nephrogenic rest had the identical mutation. Nephrogenic rests and Wilms' tumours are therefore topographically distinct lesions that are clonally derived from an early renal stem cell. Inactivation of WT1 appears to be an early genetic event which can lead to the formation of nephrogenic rests, enhancing the probability that additional genetic hits will lead to Wilms' tumour.

Association of working memory deficit and eye tracking dysfunction in schizophrenia

This study replicates our earlier findings that schizophrenic but not bipolar patients are impaired on oculomotor delayed response tasks, analogous to those used to assess spatial working memory functions of the dorsolateral prefrontal cortex (DLPFC) in monkeys (Park and Holzman, 1992). In addition, we examined the relation between working memory deficits and smooth pursuit eye movement (SPEM) dysfunction, since data from human neuropsychological and animal lesion studies implicate prefrontal pathology in both deficits. Schizophrenic patients showed marked deficits in the oculomotor memory task and the SPEM task relative to the control groups. However, they were not impaired on the oculomotor sensory task in which their responses were guided by external cues rather than by working memory. This result from outpatients replicates our earlier study which was conducted with inpatients. Within the schizophrenic group those patients with good eye tracking performed better than those with impaired pursuit on the oculomotor memory task but there was no correlation between SPEM and performance on the sensory task. These findings support the hypothesis that schizophrenics show a deficit in representational processes and add to the growing evidence for involvement of the dorsolateral prefrontal cortex in schizophrenic pathology.

Infective aortic endocarditis after percutaneous balloon aortic valvuloplasty

Infective aortic endocarditis developed in an elderly patient after a percutaneous balloon aortic valvuloplasty. The transesophageal echocardiogram demonstrated a perivalvular abscess. The patient underwent surgical replacement of the infected valve, but later succumbed to renal failure. The development of infective aortic endocarditis should be recognized as a potentially fatal complication of percutaneous balloon aortic valvuloplasty. The important measures in preventing bacteremia during percutaneous balloon aortic valvuloplasty and the appropriate role of operation are discussed.

Altered trans-activational properties of a mutated WT1 gene product in a WAGR-associated Wilms' tumor

WAGR syndrome is an acronym for a rare constellation of congenital abnormalities including predisposition to Wilms' tumor, Aniridia, Genitourinary malformations, and mental Retardation. These congenital defects are associated with a constitutional deletion affecting one copy of chromosome band 11p13, implicating the loss of one allele from a number of contiguous genes in this syndrome. Predisposition to Wilms' tumor and genitourinary abnormalities have been attributed to hemizygosity for the WT1 tumor suppressor gene, a transcriptional repressor that is normally expressed transiently during kidney development. Here we show that a Wilms' tumor arising in a child with WAGR syndrome contained a point mutation within the remaining WT1 allele. This mutation resulted in a glycine to aspartic acid substitution within the putative trans-activation domain of WT1, converting the encoded protein from a transcriptional repressor to an activator of its target DNA sequence. Thus, a critical amino acid substitution can alter the functional properties of WT1 and provide the "second hit" required for Wilms tumorigenesis.

The oncoprotein Bcl-3 can facilitate NF-kappa B-mediated transactivation by removing inhibiting p50 homodimers from select kappa B sites

Previously we have proposed a role for Bcl-3 in facilitating transactivation through kappa B sites by counteracting the inhibitory effects of bound, non-transactivating homodimers of the p50 subunit of NF-kappa B. Such homodimers are abundant for example in nuclei of unstimulated primary T cells. Here we extend the model and provide new evidence which fulfills a number of predictions. (i) Bcl-3 preferentially targets p50 homodimers over NF-kappa B heterodimers since the homodimers are completely dissociated from kappa B sites at concentrations of Bcl-3 which do not affect NF-kappa B. (ii) Select kappa B sites associate very strongly and stably with p50 homodimers, completely preventing binding by NF-kappa B. Such kappa B sites are likely candidates for regulation by p50 homodimers and Bcl-3. (iii) Bcl-3 and p50 can be co-localized in the nucleus, a requirement for active removal of homodimers from their binding sites in vivo. (iv) The ankyrin repeat domain of Bcl-3 is sufficient for the reversal of p50 homodimer-mediated inhibition, correlating with the ability of this domain alone to inhibit p50 binding to kappa B sites in vitro. Our data support the model that induction of nuclear Bcl-3 may be required during cellular stimulation to actively remove stably bound p50 homodimers from certain kappa B sites in order to allow transactivating NF-kappa B complexes to engage. This exact mechanism is demonstrated with in vitro experiments.

The early course of the Tourette's syndrome clinical spectrum

We retrospectively studied 101 children with Tourette's syndrome to characterize the early course of illness and associated behavioral disturbances of attention deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), disruptive behavior (DB), and school problems (SP). For patients without ADHD (45%), OCD (50%), DB (67%), or SP (52%) at the time of initial evaluation, 13% developed ADHD, 8% OCD, 28% DB, and 25% SP during the observation period of 1.6 +/- 1.3 years (range, 0.5 to 7 years). For patients with behavioral disturbances initially, the problems were controlled or resolved for many over time and with therapy: ADHD, 46%; OCD, 47%; DB, 50%; and SP, 67%. Medication changes, assessed after a drug adjustment period between the initial and first follow-up visits (6 +/- 6 months), showed that drug dosages remained largely unchanged and few patients required the addition of new drugs: tic suppressants, 10%; anti-obsessional agents, 5%; and stimulants, 12%. Tic suppressants were withdrawn from 12%.

The Wilms tumour gene WT1 is expressed in murine mesoderm-derived tissues and mutated in a human mesothelioma

The tumour suppressor gene WT1 encodes a transcription factor expressed in tissues of the genito-urinary system. Inactivation of this gene is associated with the development of Wilms tumour a pediatric kidney cancer. We show that WT1 is also expressed at high levels in many supportive structures of mesodermal origin in the mouse. We also describe a case of adult human mesothelioma, a tumour derived from the peritoneal lining, that contains a homozygous point mutation within WT1. This mutation, within the putative transactivation domain, converts the protein from a transcriptional repressor of its target sequence to a transcriptional activator. The role of WT1 in normal development thus extends to diverse structures derived from embryonic mesoderm and disruption of WT1 function contributes to the onset of adult, as well as pediatric, tumours.

Is there a valid association between skin tags and colonic polyps: insights from a quantitative and methodologic analysis of the literature

OBJECTIVE

To assess the reported association between skin tags and colonic polyps and to evaluate the methodologic rigor of the studies. DESIGN AND DATA IDENTIFICATION: English-language literature search using MEDLINE, Index Medicus, and bibliographic reviews of texts and all pertinent articles to perform a quantitative and methodologic analysis of all studies from 1983 (the original publication) assessing the association under study. Eligible studies were independently assessed using explicit methodologic guidelines for validity and generalizability of observational research. Two appraisers independently performed tests for heterogeneity and used meta-analytic methods in an attempt to provide summary estimates of the overall strength of association.

MEASUREMENTS AND MAIN RESULTS

Significant statistical heterogeneity across studies indicated sharp differences in the direction and magnitude of the odds ratios for the association between skin tags and colonic polyps (chi-square test of homogeneity = 37.42, 9 degrees of freedom; p < 0.005). This marked disparity prevented meaningful pooling of the individual data. The degree of statistical heterogeneity was not significantly reduced after an analysis of specific subgroups of studies. Limitations potentially responsible for the varying outcomes included lack of blinded ascertainment of clinical information, noncomparability of subjects, differing diagnostic evaluations of the colon, and uncontrolled confounding. In addition, all but one study were performed in a tertiary care setting, seriously limiting the results to the "average" subject seen in primary care settings.

CONCLUSION

Methodologic limitations and inconsistencies in study outcomes preclude the aggregation of data necessary to compute a valid and meaningful summary estimate of association. Sufficient variability prevents any consensus regarding the association between skin tags and colonic polyps. In addition, the applicability of the results is limited primarily to subjects seen in tertiary care centers, limiting the overall clinical usefulness of skin tags as "biomarkers" of colonic polyps. Recommendations for further research are provided.

Antithrombotic activity of a lumbrokinase immobilized polyurethane surface

Six fractions of strong and novel fibrinolytic enzymes (lumbrokinase, LK) were extracted from the earthworm Lumbricus rubellus. The enzymes in these fractions appeared to be very stable and showed greater antithrombotic activity than other currently used antithrombotics. The authors immobilized an LK fraction that shows the most potent fibrinolytic activity on a polyurethane (PU) surface to investigate its enzymatic and antithrombotic activity. The methanol extracted PU surface was treated with a 3% (wt/vol) maleic anhydride methylvinyl ether copolymer (MAMEC) solution and finally incubated in an LK solution in PBS (pH 7.4). The immobilized LK activity was estimated by the fibrin plate method and caseinolytic activity assay. The antithrombotic activity was evaluated by in vitro 125I-fibrinogen adsorption in fresh whole blood and 99mTc platelet adhesion tests. In addition, the occlusion time was determined through ex vivo rabbit A-A shunt experiments. The content and unit activity of immobilized LK were found to be 24 micrograms/cm2 and 18 IU/cm2, respectively. The relative activity ratio of immobilized LK to soluble LK was found to be approximately 34%. Immobilized LK was stable within a various pH range and resistant to inhibitors and thermal inactivation. Less fibrinogen was adsorbed and fewer platelets adhered on an LK-immobilized surface than on PU and PU-MAMEC controls. The ex vivo occlusion time of untreated PU and PU-MAMEC surfaces were only 32 and 42 minutes, respectively. But that of LK-immobilized PU was extended to 140 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)

Median cleft of the lower lip, mandible and manubrium. A case report

There is a wide variation in the severity of median clefts of the lower lip and mandible. We report a severe case demonstrating clefts of the lower lip and mandible together with lack of supporting structures in the neck and upper sternum. Since a case with a cleft of the manubrium sterni is very rare, the literature is reviewed and discussed.

[Studies on interdigestive intestinal motility of the orthotopic allotransplanted canine small bowel]

We evaluated interdigestive motor patterns in the allotransplanted small bowel, in comparison with orthotropic allotransplanted canine jejunoileum and orthotropicaly autotransplanted canine jejunoileum or intact ones by using strain gage force transducers which were sewn to the serosal surfaces of the duodenum, jejunum and ileum. Interdigestive intestinal motility of each conscious dogs was recorded at 2 weeks, 4 weeks and 8 weeks after each operation. 1. No significant differences were recognized on the mean durations of Interdigestive migrating contractions (IMC) of the duodenum among three groups. 2. Interdigestive migrating contractions (IMC) appeared at the autotransplanted jejunoileum with shorter duration than duodenum, and lacked of coordination between the intact duodenum and the transplanted jejunoileum for at least 8 weeks after the operation. 3. IMC also appeared at the allotransplanted jejunoileum with shorter duration than duodenum and lacked of coordination between the intact duodenum and the transplanted jejunoileum for at least 8 weeks after the operation. These characteristic motor patterns were similar to those of autotransplanted dogs. These observations suggest that intrinsic nervous system, believed to be important for initiation of the IMC of small bowel, were preserved even in the allotransplanted small bowel. Thereafter, effective immunosuppression must allow small bowel allotransplantation to become clinical reality.

Physical and functional interaction between WT1 and p53 proteins

WT1 is a tumor-suppressor gene expressed in the developing kidney, whose inactivation leads to the development of Wilms tumor, a pediatric kidney cancer. WT1 encodes a transcription factor which binds to the EGR1 consensus sequence, mediating transcriptional repression. We now demonstrate that p53, the product of a tumor-suppressor gene with ubiquitous expression, physically associates with WT1 in transfected cells. The interaction between WT1 and p53 modulates their ability to transactivate their respective targets. In the absence of p53, WT1 acts as a potent transcriptional activator of the early growth response gene 1 (EGR1) site, rather than a transcriptional repressor. In contrast, WT1 exerts a cooperative effect on p53, enhancing its ability to transactivate the muscle creatine kinase promoter.