Individual differences in spatial working memory in relation to schizotypy

With a delayed-response task, spatial working memory function was assessed in normal students who were selected for schizotypy. The Wisconsin Card Sorting Test was also administered. Twenty-eight undergraduate students who scored high on the Perceptual Aberration Scale (PerAb) and 23 who scored low on this scale participated in this study. High PerAb students performed less accurately compared with the low PerAb controls on the delayed-response task, and they were more than twice as likely as low PerAb students to be impaired. The groups did not differ in the number of perseverative errors or number of categories achieved on the Wisconsin Card Sorting Test, but, as predicted, high PerAb students were less able to maintain set than were the low PerAb students. Neuropsychological implications of these data are discussed.

Insulin, but not estrogen, correlated with indexes of desaturase function in obese women

This study determined the associations of serum insulin and estrogen with fatty acid composition, fatty acid product/substrate ratios used as indexes of desaturase enzyme function, and platelet aggregation in obese and lean women. Thirty women were classified as obese (n = 8) or lean (n = 21) based on body mass index. Obese women were characterized by higher insulin levels (p < 0.05) but fasting glucose levels did not differ (p > 0.05) from lean women. Insulin positively correlated with increased C20:4n6/C18:3n6 (index of delta 5-desaturase) (p < 0.05) and C20:4n6/C18:2n6 (index of overall n6 pathway activity) (p < 0.01) in serum, and the n5 pathway in platelets (p < 0.01), but there was no correlation for insulin with platelet C18:3n6/C18:2n6 (index of delta 6-desaturase activity). Insulin was also positively related (p < 0.01) to aggregation as measured by impedance and negatively related to lag time (p < 0.05). Platelets of obese women aggregated more (p < 0.05) compared to lean women and began aggregating faster (p < 0.05), suggesting the possibility that the obese women were at greater risk for enhanced blood clotting. Plasma estrogen was correlated with age (p < 0.05) but not for other variables studied (p > 0.05). Insulin, but not estrogen, appears to influence desaturase activity, as demonstrated by increased desaturase function associated with hyperinsulinemia in obese women.

Individual differences in spatial working memory in relation to schizotypy

With a delayed-response task, spatial working memory function was assessed in normal students who were selected for schizotypy. The Wisconsin Card Sorting Test was also administered. Twenty-eight undergraduate students who scored high on the Perceptual Aberration Scale (PerAb) and 23 who scored low on this scale participated in this study. High PerAb students performed less accurately compared with the low PerAb controls on the delayed-response task, and they were more than twice as likely as low PerAb students to be impaired. The groups did not differ in the number of perseverative errors or number of categories achieved on the Wisconsin Card Sorting Test, but, as predicted, high PerAb students were less able to maintain set than were the low PerAb students. Neuropsychological implications of these data are discussed.

Purification and characterization of LasD: a second staphylolytic proteinase produced by Pseudomonas aeruginosa

We have previously described studies of a 22 kDa active fragment of the LasA proteinase. In follow-up studies of LasA, we have discovered the separate existence of a 23 kDa proteinase which shares many of the enzymatic properties of LasA, including the ability to lyse heat-killed staphylococci. However, this apparent serine proteinase, which we designate LasD, is distinct from the 22 kDa active LasA protein for the following reasons: (i) the N-terminal sequence of LasD shares no homology with LasA or the LasA precursor sequence; (ii) Pseudomonas aeruginosa LasA mutant strains AD1825 and FRD2128 do not produce LasA yet produce LasD; and (iii) specific antibodies to each proteinase do not show any cross-reactivity. LasD appears to be produced as a 30 kDa protein, which is possibly cleaved to produce a 23 kDa active fragment. The purified LasD fragment (23 kDa) shows strong staphylolytic activity only at higher pH conditions, while LasA exhibits staphylolytic activity over a broad pH range. In addition to their ability to cleave at internal diglycine sites, both the LasD and LasA endoproteinases efficiently cleave beta-casein.

Colorimetric microwell plate hybridization assay for detection of amplified Mycobacterium tuberculosis DNA from sputum samples

We developed a colorimetric microwell plate hybridization assay (CoMPHA) for the specific detection of 5'-biotinylated amplified Mycobacterium tuberculosis DNA. The optical densities of the CoMPHA corresponded to the initial amounts of purified template DNA. Here, we show that the CoMPHA is useful in distinguishing the PCR-positive and PCR-negative samples.

Surface characteristics and properties of lumbrokinase-immobilized polyurethane

Potent and novel fibrinolytic enzymes (lumbrokinase [LK]) were extracted from the earthworm, Lumbricus rubellus. These enzymes were very stable and showed greater antithrombotic activity than other currently used fibrinolytic proteins. An LK fraction showing the most potent fibrinolytic activity was immobilized onto a polyurethane (PU) surface to investigate its enzymatic activity and antithrombotic activity. A methanol-extracted PU surface was coated with 3% (wt/vol) maleic anhydride methylvinyl ether copolymer (MAMEC)/tetrahydrofuran (THF) solution, and the surface was incubated in an LK solution/phosphate-buffered saline (PBS, pH 7.4). The surface properties were characterized by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), electron spectroscopy for chemical analysis (ESCA), and dynamic contact angle. The stability of immobilized LK was determined by caseinolytic activity assay and the specificity of immobilized LK on fibrinogen/fibrin was observed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The antithrombotic activity of immobilized LK was evaluated using an ex vivo rabbit A-A shunt experiment. LK immobilization was confirmed by ATR-FTIR and ESCA. Immobilized LK demonstrated stable proteolytic activity during various incubation periods. Immobilized LK proteolyzed fibrinogen and fibrin almost specifically, while it hardly hydrolyzed other plasma proteins including plasminogen and albumin. In the ex vivo A-A shunt experiment, the LK-immobilized surface significantly prolonged occlusion time over control surfaces. This is primarily due to the high thrombolytic activity of immobilized LK. In this work, a highly efficient surface modification method on the PU surface was developed, and this LK immobilization technique will be very useful in improving the blood compatibility of blood-contacting devices.

Relative effects on serum lipids and apolipoproteins of a caprenin-rich diet compared with diets rich in palm oil/palm-kernel oil or butter

Two randomized, blind studies measured changes in serum cholesterol, other serum lipids, and apolipoprotein (apo) concentrations in hypercholesterolemic men consuming caprenin (Cap)-rich diets after either baseline diets enriched in palm oil/palm-kernel oil (PO/PKO) or butter. The triglyceride Cap contains 45% 22:0 and 50% 8:0-10:0. Compared with baseline values established at 3 wk on the PO/PKO diet, the 17 subjects on the Cap diet showed significant reductions after 6 wk in HDL cholesterol (HDL-C), HDL2-C, and HDL3-C and a significant increase in the ratio of total cholesterol, LDL-C, triglycerides, apo B-100, or apo A-I were seen. Compared with baseline values established at 3 wk on the butter diet, after 6 wk the seven subjects receiving the Cap diet showed no significant changes in the lipid and apolipoprotein indexes analyzed. These data show that one or more of 8:0, 10:0, and 22:0 fatty acids can contribute to hypercholesterolemia in men.

The pattern of palatal rugae in submucous cleft palates and isolated cleft palates

The early diagnosis of submucous cleft palate is important. In children too young to tolerate nasendoscopy and videofluoroscopy the diagnosis depends on the clinical history and intraoral examination. We have studied the pattern of the hard palate rugae to investigate their possible diagnostic significance. Maxillary dental casts were obtained from 16 patients with submucous cleft palate, 17 patients with isolated clefts of the secondary palate, and 10 non-cleft controls. The hard palate mucosa had a unique feature in 14 (87.5%) of the submucous cleft palates: one or more of the palate rugae curved towards the region of the bony notch in the posterior border of the hard palate. The 2 cases without this rugae pattern did not have a detectable bony notch. In 100% of the isolated cleft palate cases, one or more of the rugae curved towards the anterior end of the cleft. This feature was not seen in any of the non-cleft controls. We consider this rugae pattern to be an additional diagnostic feature of submucous cleft palate.

Antithrombogenicity of lumbrokinase-immobilized polyurethane

Lumbrokinase is a potent fibrinolytic enzyme purified from the earthworm, Lumbricus rubellus. We immobilized 18 IU/cm2 of lumbrokinase to polyurethane using maleic anhydride methylvinyl ether copolymer (MAMEC) as an enzyme carrier, and the proteolytic and fibrinolytic activities of immobilized lumbrokinase were assayed. Immobilized lumbrokinase retained about 34% of its activity, compared with soluble lumbrokinase activity. Immobilized lumbrokinase showed stability against thermal inactivation and degradation and within a various pH range. The optimal pH of immobilized lumbrokinase shifted 1.0 pH unit upward compared with soluble enzyme. Upon exposure to the human whole blood, less amount of 125I-fibrinogen was adsorbed to lumbrokinase-immobilized surface than to the polyurethane control surface. The lumbrokinase-immobilized surface showed less platelet adhesion than did the MAMEC-grafted surface. At the early stage of platelet adhesion, the number of adhered platelets increased on the lumbrokinase-immobilized surface with increasing time; yet, the platelet number drastically decreased on the lumbrokinase-immobilized surface after 80 min incubation. This suggests that lumbrokinase-immobilized polyurethane digested the adsorbed fibrinogen and inhibited platelet adhesion on the surface, probably by inhibiting fibrinogen adsorption to be highly antithrombogenic. Clinical applications of this material to artificial organs should be developed in the near future.

Using the assessment of motor and process skills to compare occupational performance between clinic and home settings

OBJECTIVES

The study described in this article examined the effect of home versus clinic settings on the instrumental activities of daily living (IADL) performance of older adults.

METHOD

Twenty older adults living in the community were evaluated in their homes and in an occupational therapy clinic with the Assessment of Motor and Process Skills (AMPS). The motor and process ability measures were compared between the two settings with many-faceted Rasch analysis.

RESULTS

The subjects' motor ability measures tended to remain stable from clinic to home settings. The process ability measures tended not to remain stable from clinic to home settings, because 10 of the 20 subjects performed significantly better in their homes.

CONCLUSION

These findings support the idea that process skill abilities are affected by the environment to a greater degree than are motor skills abilities and that for persons living in the community, the familiar home environment tends to support IADL performance. If an occupational therapist wants to know how a person performs IADLs, the therapist should evaluate that person's performance in the environment in which the client will be functioning.

Chronic cardiac rejection masking as constrictive pericarditis

The hemodynamic changes consistent with constrictive pericarditis are often encountered in patients who have undergone cardiac transplantation. We describe here 4 patients who underwent pericardiectomy after cardiac transplantation. All were found to have evidence of a thickened and constricting peel of pericardium at surgical exploration. Their postoperative clinical courses were variable. One patient with primarily effusive constriction experienced marked improvement. Three patients failed to show clinical improvement and had persistently elevated atrial and ventricular end-diastolic pressures. A coexisting restrictive cardiomyopathy secondary to chronic rejection, coronary arteriopathy, or long-standing constriction may have been the cause of this poor outcome. Many patients with transplanted hearts exhibit evidence of poor diastolic ventricular compliance without evidence of classic constriction; some manifest both the restrictive and constrictive components. The careful selection of patients with constrictive pericarditis can optimize the outcome.

Protein kinase C association with the retinal cytoskeleton and phosphorylation of vimentin

Protein kinase C plays an important role in regulation of the cytoskeleton. We found that protein kinase C activity is associated with the retinal cytoskeleton, and that it catalyses the stoichiometric phosphorylation of two cytoskeletal proteins, with apparent molecular masses of 56 kDa and 100 kDa. The 56-kDa substrate was identified as vimentin on the basis of its apparent molecular mass, pI, solubility, immunoreactivity, pattern of proteolysis by Lys-C and a partial amino acid sequence. Immunomicroscopy was consistent with previous reports that in the retina vimentin has the unusual property of being present in neuronal cells--horizontal cells--as well as non-neuronal cells. The characteristics of protein kinase C phosphorylation of vimentin that was enriched in neuronal vimentin were determined. Hyperactivation of protein kinase C by treatment of retinas with phorbol myristate acetate resulted in the phosphorylation of vimentin in situ, indicating that the phosphorylation is physiologically relevant. In vitro, purified retinal protein kinase C catalysed the incorporation of nearly 2 mol phosphate per mole of monomeric vimentin. The phosphorylation was highly dependent on the presence of phosphatidylserine. Thus, protein kinase C functions in the retinal cytoskeleton, where a major role is in the modification of vimentin. The characterization of the phosphorylation of outer retinal vimentin by protein kinase C provides a basis for further studies on the regulation and function of this cytoskeletal element.

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.

Possible roles of LFA-1 and Fc gamma receptors on the functional immaturities of cord blood polymorphonuclear leukocytes

The functional immaturity of PMNs is one of the major causes of overwhelming sepsis in newborns. In this study, we observed functions and surface markers of PMNs to investigate what causes the functional immaturity of PMNs in newborns. As results, the percentage of EA rosette forming PMNs (58.5 +/- 15.5%) and the chemotactic movement (0.14 +/- 0.09 mm) of cord blood PMNs were significantly lower than those of adult peripheral blood PMNs (70.8 +/- 9.9%, 0.60 +/- 0.34 mm). Cord blood PMNs showed decreased glass adherence and ADCC activity. The expression of Fc gamma RII or Fc gamma RIII was a little lower than those of adult peripheral blood PMNs, but the expression of Fc gamma RI (43.1 +/- 26.8%) was significantly higher than that of adult peripheral blood PMNs (3.2 +/- 1.8%). There was a significant difference in LFA-1 expression between EA rosette forming PMNs (92.9 +/- 9.1%) and EA rosette non-forming PMNs (25.6 +/- 22.6%). From these results, it is assumed that neonatal PMNs may consist of heterogeneous populations. And the relatively high percentage of EA rosette non-forming PMNs which express a low level of LFA-1 may be responsible for the functional immaturity of cord blood PMNs.

Neurofibromatosis type 1 gene product (neurofibromin) associates with microtubules

The neurofibromatosis type 1 (NF1) gene was recently identified by positional cloning and found to encode a protein with structural and functional homology to mammalian and yeast GTPase-activating proteins (GAPs). Using antibodies directed against the NF1 gene product, a protein of approximately 250 kDa was identified and termed neurofibromin. Double-indirect immunofluorescent labeling with anti-neurofibromin and anti-tubulin antibodies demonstrates that neurofibromin associates with cytoplasmic microtubules. Immunoblotting of microtubule-enriched cytoplasmic fractions, using antibodies generated against neurofibromin, shows that neurofibromin copurifies with microtubules. When portions of neurofibromin are expressed in Sf9 insect cells they associate with polymerized microtubules; furthermore, the critical residues for this interaction reside within the GAP-related domain of neurofibromin. The unexpected association of neurofibromin with microtubules suggests that neurofibromin is involved in microtubule-mediated intracellular signal transduction pathways.

Critical appraisal of the angiographic portacaval shunt (TIPS)

The transjugular intrahepatic portacaval shunt (TIPS) is a novel angiographic method for achieving portal decompression without operation. Fifty-nine consecutive patients underwent a total of 80 consecutive TIPS procedures. The procedure was unsuccessful in 4 patients (7%) and initially succeeded in 55 (93%). Eighteen patients (30%) underwent 2 or more TIPS procedures during the same hospitalization due to technical difficulties, early rebleeding, shunt stenosis, or thrombosis. Early TIPS occlusion occurred in seven patients (12%) and led to recurrent variceal hemorrhage in five. Forty-two percent of the cases of persisting or recurrent bleeding were nonvariceal. Procedure-related complications occurred in 10% of TIPS procedures or 14% of patients. Twenty-three patients (39%) were actively bleeding at the time of the procedure, and, in 6 of these (26%), bleeding was never controlled. In-hospital mortality (25%) was related only to the presence of bleeding at the time of TIPS (56% for emergent versus 5.5% for non-emergent, p < 0.0001). Mortality was not related to the Child-Pugh classification. Hemodynamic stabilization, vasoconstrictor therapy, balloon tamponade, and sclerotherapy were underutilized in 30% to 40% of patients prior to TIPS. Aggressive medical management should be used to stop variceal hemorrhage prior to TIPS in all patients, regardless of the Child-Pugh classification. Prospective trials comparing TIPS with sclerotherapy and surgical shunt are required to demonstrate the proper role of this procedure in the management of portal hypertension and variceal hemorrhage.

Magnetic resonance abnormalities in HIV infection: a study in the drug-user risk group

Cognitive impairment is a frequent complication of advanced human immunodeficiency virus-1 (HIV-1) infection. However, structural imaging of the brain has not revealed abnormalities that precede the onset of clinical abnormalities. Cranial magnetic resonance (MR) studies were performed in 28 male subjects with intravenous drug use histories; nine were HIV-1 seronegative, 11 were HIV-1 seropositive but asymptomatic, and eight were seropositive and met symptomatic criteria for acquired immune deficiency syndrome (AIDS). Cortical atrophy, but not the degree of ventricular enlargement or signal abnormalities, was increased in the seropositive group compared with the seronegative group and also differed between asymptomatic seropositive and seronegative patients. An increased level of cortical atrophy may reflect the early impact of HIV-1 infection on the brain.

The thrombolytic effect of lumbrokinase is not as potent as urokinase in a rabbit cerebral embolism model

The purpose of the present study is to determine whether lumbrokinase has an in vivo thrombolytic effect in a rabbit cerebral embolism model. In our previous studies, we found that lumbrokinase, an extract from Korean earth worms, has a strong in vitro fibrinolytic effect without the presence of plasminogen and significant in vivo thrombolytic effects of lumbrokinase in a rat human-clot-induced cerebral embolism model. We established the cerebral embolism model in rabbits by injecting a piece of human clot into the internal carotid artery via the external carotid artery and confirmed the occlusion with angiography. Twenty one rabbits were divided into three groups and 5cc of saline, urokinase of 50,000 u/ml, and equipotent LK were injected intraarterially for 30 minutes into each group of 7 animals. Ten minutes after the end of infusion, an angiogram was performed to confirm the recanalization. Clot lysis occurred in one, six, and one animals in the saline, urokinase and lumbrokinase treated groups respectively. With regard to its in vitro effect, lumbrokinase is not as potent in vivo. Further investigation should be performed to determine the cause of its weakened in vivo effect and to develop a method to potentiate it.

Mutual regulation of the transcriptional activator NF-kappa B and its inhibitor, I kappa B-alpha

The NK-kappa B transcription factor complex is sequestered in the cytoplasm by the inhibitory protein I kappa B-alpha (MAD-3). Various cellular stimuli relieve this inhibition by mechanisms largely unknown, leading to NF-kappa B nuclear localization and transactivation of its target genes. It is demonstrated here with human T lymphocytes and monocytes that different stimuli, including tumor necrosis factor alpha and phorbol 12-myristate 13-acetate, cause rapid degradation of I kappa B-alpha, with concomitant activation of NF-kappa B, followed by a dramatic increase in I kappa B-alpha mRNA and protein synthesis. Transfection studies reveal that the I kappa B-alpha mRNA and the encoded protein are potently induced by NF-kappa B and by homodimers of p65 and of c-Rel. We propose a model in which NF-kappa B and I kappa B-alpha mutually regulate each other in a cycle: saturating amounts of the inhibitory I kappa B-alpha protein are destroyed upon stimulation, allowing rapid activation of NF-kappa B. Subsequently, I kappa B-alpha mRNA and protein levels are quickly induced by the activated NF-kappa B. This resurgence of I kappa B-alpha protein acts to restore an equilibrium in which NF-kappa B is again inhibited.

The oncoprotein Bcl-3 directly transactivates through kappa B motifs via association with DNA-binding p50B homodimers

Bcl-3 is an I kappa B-related protein with ankyrin repeat motifs. Its gene is located at a site of recurrent translocations in a subset of B cell chronic lymphocytic leukemias. Bcl-3 associates tightly with p50B (NFKB2, p52) homodimers in cells, and together these proteins form a ternary complex with DNA at kappa B sites. Such an association functionally leads to a novel and potent form of transactivation through the kappa B motif: the tethering of Bcl-3 to DNA via the p50B homodimers allows Bcl-3 to transactivate directly, while p50B homodimers alone cannot. Transactivation mediated by Bcl-3 requires two cooperating domains located amino- and carboxy-terminal to the ankyrin domain. Bcl-3 is localized to the nucleus, and a Bcl-3-p50B complex is detected in certain lymphoid cells. Our data reveal a novel role for Bcl-3, distinct from that of the inhibitor I kappa B. The results have implications for tumorigenesis.

Sequence and chromosomal localization of two PET genes required for cytochrome c oxidase assembly in Saccharomyces cerevisiae

The nuclear genes PET117 and PET191 are required for the assembly of active cytochrome c oxidase in S. cerevisiae, yet their gene products are not subunits of the final assembled cytochrome c oxidase complex. Plasmids bearing PET117 or PET191 were isolated by their ability to complement the pet117-1 or pet191-1 mutations, respectively. By restriction mapping, subcloning, and deletion analysis of yeast DNA fragments that complement these mutations, the PET117 and PET191 genes were localized to smaller regions of DNA, which were then sequenced from both strands. The PET117 open reading frame is of 107 codons and the PET191 open reading frame is of 108 codons. Neither the PET191 nor PET117 DNA sequences have been reported previously, and the derived amino-acid sequences of the PET191 and PET117 open reading frames exhibit no significant primary amino-acid sequence similarity to other protein sequences available in the NBRF data base, or from translated Genbank sequences. By hybridization of PET117 or PET191 probes first to a chromosome blot and next to a library of physically mapped fragments of yeast genomic DNA, the map locations of the PET191 and PET117 genes were determined. PET117 is located on chromosome V near the HIS1 gene and PET191 is located on chromosome X near the CYC1 gene.

Acute leukemias with unusual immunophenotypes

Over a two-year period, immunophenotypic patterns of 266 acute leukemia cases were analyzed using a panel of tests including TdT, SmIg and 9 surface antigens by the immunofluorescence stains for the assessment of the incidence and grade of phenotypic ambiguity (lineage infidelity) and the possible clinical significance of unusual immunophenotypes. Immunophenotypes were classified into four groups according to the degree of ectopic antigen expression. We classified as Group A (91.7%, 244 of 266 cases) those expressing conventional pattern without ectopic antigen. Group B (3.0%, 8 of 266 cases) was defined to have at least two lineage specific markers and single ectopic antigen. Such a "low grade deviation" did not prevent a definite immunodiagnosis. Group C (4.2%, 11 of 266 cases) revealed a promiscuous coexpression of markers related to different lineages, including two cases (0.8%, 2 cases) of biphenotypic leukemia. Group D (1.1%, 3 cases) included unclassifiable immunophenotypes with no antigen or HLA-DR only expression. Both patients with biphenotypic leukemia and one patient with unclassifiable immunophenotypes failed to respond to induction chemotherapy, suggesting a poor prognosis in these patients. The incidence of acute myelogenous leukemia (AML) cases with one or more ectopic surface antigens was 10 (8.1%) of the 124 AML cases. Ectopic antigen expression was seen in 5 (4%) of the 125 B-lineage acute lymphoblastic leukemia (ALL) cases and 3 (25%) of the 12 T-ALL cases. It is concluded that nearly 95% of cases of acute leukemia cases can be diagnosed accurately with immunophenotyping alone including patients with a mild degree of deviation from expected antigenic patterns.(ABSTRACT TRUNCATED AT 250 WORDS)

Schizophrenics show spatial working memory deficits

The present study demonstrates that schizophrenics are impaired on spatial delayed-response tasks, analogous to those that have been used to assess the working memory function of the dorsolateral prefrontal cortex in rhesus monkeys. Schizophrenic patients and two control groups, normal subjects and bipolar psychiatric patients, were tested on the oculomotor version of the memory task, a haptic version of the same task, and two control tasks: a sensory task that did not require working memory and a digit span test. The schizophrenic patients showed marked deficits relative to the two control groups in both the oculomotor and haptic delayed-response tasks. They were not, however, impaired on the digit span test, which taps verbal working memory as well as voluntary attention, and on the sensory control task, in which their responses were guided by external cues rather than by spatial working memory. These findings provide direct evidence that schizophrenics suffer a loss in representational processing and that this deficit is modality independent. These data on spatial working memory add to the growing evidence for involvement of the dorsolateral prefrontal cortex in schizophrenic disease.