Nevus anemicus associated with neurofibromatosis type 1 in a neonate: a case report.

Neurofibromatosis type 1 (NF1) is a multisystemic autosomal dominant disease affecting approximately 1 individual in 3500. The diagnostic criteria developed by NIH in 1988 allow unequivocal diagnosis in all cases but the youngest children. Due to the variable phenotypic expression, the diagnosis of NF1 in the youngest may be challenging, particularly when the distinctive cutaneous lesions are missing. We describe the case of a neonate who presented at birth solely with a nevus anemicus. Although this is not considered a diagnostic feature, given the presence of a few café au lait lesions in the patient's father, the genetic test was performed and the diagnosis of NF1 confirmed. To our knowledge, the association between nevus anemicus and NF1 is only anedoctal. The peculiarity clinical manifestation of this case highlights the high variable expressivity of the NF1 gene mutation and reinforces the importance of genetic counseling in affected individuals.

Familial aggregation in Progressive Supranuclear Palsy and Corticobasal Syndrome.

BACKGROUND: Studies on familial aggregation might be of help to evaluate whether the genetic background has a key role in Progressive Supranuclar Palsy (PSP) and Corticobasal Syndrome (CBS). Only a few studies are available. OBJECTIVE: To evaluate the prevalence of positive family history (FH) in PSP and CBS in a large sample of patients. METHODS: Two hundred and thirty patients and 110 controls entered the study. Patients underwent an extensive clinical, neurological and neuropsychological assessment as well as a structural brain imaging study. A clinical follow-up further confirmed the diagnosis. Familial aggregation was carefully recorded by a standardised questionnaire. RESULTS: One hundred and twenty-nine PSP (age at onset = 66.6 +/- 7.3, female = 46.1%) and 101 CBS (age at onset = 62.8 +/- 8.9, female = 41.6%) were consecutively enrolled. Positive FH was found in 31.8% of PSP (n = 41) and in 31.7% of CBS (n = 32). Familial aggregation was lower in the age-matched control group compared to patient group (21.8%, P = 0.05). Patients with PSP had higher positive FH for Parkinsonism (63.4%) when compared to FH for dementia (36.6%). In CBS, FH was equally distributed between Parkinsonism (53.1%) and dementia (46.9%). In addition, FH was not associated with age at disease onset in PSP (FH+ versus FH-, 67.0 +/- 7.3 vs. 66.7 +/- 7.1, P = 0.788) and in CBS (62.6 +/- 7.9 vs. 62.9 +/- 9.5, P= 0.877). CONCLUSIONS: These results argue for familial aggregation in PSP and CBS, further underlying the importance of genetic background in these disorders. Further studies on possible genetic modulators or genetic epistasis contributing to PSP and CBS development are warranted.

The FTLD-modified Clinical Dementia Rating scale is a reliable tool for defining disease severity in frontotemporal lobar degeneration: evidence from a brain SPECT study.

BACKGROUND: Frontotemporal Lobar Degeneration (FTLD) is a heterogeneous disorder characterized by impairment in executive functions, behavioural disturbance and language deficit. Reliable scales of global impairment are under evaluation. A consortium of Mayo Clinic and University of California FTLD Centers has recently developed the FTLD-modified Clinical Dementia Rating (CDR) scale to assess FTLD severity. OBJECTIVE: To evaluate whether FTLD-modified CDR scores correlate with the pattern and degree of brain SPECT hypoperfusion in patients with FTLD. METHODS: Ninety-nine patients with FTLD entered the study. Patients underwent a clinical evaluation and a wide standardized neuropsychological assessment, including mini-mental state examination (MMSE) and FTLD-modified CDR. A brain SPECT perfusion imaging study was carried out in each patient. A linear correlation analysis between frontotemporal dementia-modified CDR or neuropsychological tests scores and perfusion data was performed. RESULTS: There was a significant relationship between higher FTLD-modified CDR score and lower global regional cerebral blood flow in the frontal and temporal lobes, bilaterally. No significant correlation between MMSE and brain frontotemporal hypoperfusion was found. The correlation between brain hypoperfusion pattern and neuropsychological test scores tapping different cognitive domains fitted with previously published data. CONCLUSIONS: The recently introduced FTLD-modified CDR scale correlates with the degree of frontotemporal hypoperfusion in patients with FTLD. This study confirms and further supports the usefulness of FTLD-modified CDR in future clinical trials to monitor disease progression.

Levels of circulating endothelial progenitor cells are related to uremic toxins and vascular injury in hemodialysis patients.

BACKGROUND: Patients suffering from chronic kidney diseases (CKD) exhibit cardiovascular diseases and profound endothelial dysfunction. CKD patients have reduced numbers of endothelial progenitor cells, but little is known about the factors influencing these numbers. OBJECTIVES: Among these factors, we hypothesized that uremic toxins and vascular injury affect endothelial progenitor cells. PATIENTS/METHODS: Thirty-eight hemodialysis patients were investigated and compared with 21 healthy controls. CD34+CD133+ immature progenitors, CD34+KDR+ endothelial progenitors cells (EPC) and myeloid EPC (mEPC) were counted in peripheral blood. Levels of uremic toxins beta(2)-microglobulin, indole-3 acetic acid, indoxylsulfate, p-cresylsulfate and homocysteine were measured. Vascular injury was assessed in hemodialysis (HD) patients by measuring aortic pulse wave velocity and plasma levels of endothelial microparticles. In vitro experiments were performed to study the effect of uremic toxins on apoptosis of progenitor cells. RESULTS AND CONCLUSIONS: CD34+CD133+ immature progenitor cell number was negatively correlated with the levels of uremic toxins beta(2)-microglobulin and indole-3 acetic acid. In vitro, indole-3 acetic acid induced apoptosis of CD133+ cells. These data indicate uremic toxins have a deleterious role on progenitor cells, early in the differentiation process. Moreover, mEPC number was positively correlated with markers of vascular injury-pulse wave velocity and endothelial microparticle levels. This suggests that vascular lesions could stimulate progenitor cell mobilization, even in a context of reduced EPC induced by CKD. In conclusion, uremic toxins and vascular injury appear to affect endothelial progenitor cell biology in CKD.

The uremic solute indoxyl sulfate induces oxidative stress in endothelial cells.

BACKGROUND: Endothelial dysfunction and oxidative stress are matters of concern in patients with chronic renal failure (CRF). Uremic solutes retained in these patients could be involved in these processes. Notably, the protein-bound uremic solute indoxyl sulfate induces endothelial dysfunction in vitro, and has shown pro-oxidant effects. OBJECTIVE: To demonstrate that indoxyl sulfate is a potential mediator of oxidative stress in endothelial cells in vitro. METHODS: Indoxyl sulfate-induced oxidative stress in human umbilical vein endothelial cells (HUVEC) was studied by measuring reactive oxygen specie (ROS) production by cytofluorimetry, by analyzing the involvement of the pro-oxidative enzymes NAD(P)H oxidase, xanthine oxidase, and NO synthase, and by measuring the levels of the non-enzymatic antioxidant glutathione. RESULTS: We showed that indoxyl sulfate induced a significant production of ROS in HUVEC, with or without human serum albumin. We then investigated the role of pro-oxidative enzymes and measured the levels of the antioxidant glutathione. The NAD(P)H oxidase inhibitors, DPI, and apocynin, inhibited ROS production, whereas inhibitors of xanthine oxidase, NO synthase, and mitochondrial ROS had no effect. Interestingly, indoxyl sulfate strongly decreased the levels of glutathione, one of the most active antioxidant systems of the cell. In addition, the ROS production mediated by indoxyl sulfate was inhibited by the antioxidants vitamin C, vitamin E, and NAC. CONCLUSION: The uremic solute indoxyl sulfate enhances ROS production, increases NAD(P)H oxidase activity, and decreases glutathione levels in endothelial cells. Thus, indoxyl sulfate induces oxidative stress by modifying the balance between pro- and antioxidant mechanisms in endothelial cells.

Elevation of circulating endothelial microparticles in patients with chronic renal failure.

BACKGROUND: Chronic renal failure patients are at high risk of cardiovascular events and display endothelial dysfunction, a critical element in the pathogenesis of atherosclerosis. Upon activation, the endothelium sheds microparticles, considered as markers of endothelial dysfunction that also behave as vectors of bioactive molecules. AIM: To measure plasma levels of endothelial microparticles (EMPs) in chronic renal failure patients (CRF), either undialyzed or hemodialyzed (HD), and to investigate the ability of uremic toxins to induce EMP release in vitro. METHODS: Circulating EMPs were numerated by flow cytometry, after staining of platelet-free plasma with phycoerythrin (PE)-conjugated anti-CD144 (CD144+ EMP) or anti-CD146 (CD146+ EMP) monoclonal antibodies. Platelet MP (CD41+ PMP), leukocyte MP (CD45+ leukocyte microparticles (LMP)), and annexin-V+ MPs were also counted. In parallel, MPs were counted in supernatant of human umbilical vein endothelial cells incubated with uremic toxins [oxalate, indoxyl sulfate, p-cresol, and homocysteine (Hcy)], at concentrations found in patients. RESULTS AND CONCLUSIONS: CD144+ EMP and CD146+ EMP levels were significantly higher in CRF and HD patients than in healthy subjects. Furthermore, annexin-V+ MPs were elevated in both groups of uremic patients, and CD41+ PMP and CD45+ LMP were increased in CRF and HD patients, respectively. In vitro, p-cresol and indoxyl sulfate significantly increased both CD146+ and annexin-V+ EMP release. Increased levels of circulating EMP in CRF and HD patients represent a new marker of endothelial dysfunction in uremia. The ability of p-cresol and indoxyl sulfate to increase EMP release in vitro suggests that specific uremic factors may be involved in EMP elevation in patients.

Biophysical characterization of lithostathine. Evidences for a polymeric structure at physiological pH and a proteolysis mechanism leading to the formation of fibrils.

Lithostathine is a calcium carbonate crystal habit modifier. It is found precipitated under the form of fibrils in chronic calcifying pancreatitis or Alzheimer's disease. In order to gain better insight into the nature and the formation of fibrils, we have expressed and purified recombinant lithostathine. Analytical ultracentrifugation and quasi-elastic light scattering techniques were used to demonstrate that lithostathine remains essentially monomeric at acidic pH while it aggregates at physiological pH. Analysis of these aggregates by electron microscopy showed an apparently unorganized structure of numerous monomers which tend to precipitate forming regular unbranched fibrils. Aggregated forms seem to occur prior to the apparition of fibrils. In addition, we have demonstrated that these fibrils resulted from a proteolysis mechanism due to a specific cleavage of the Arg(11)-Ile(12) peptide bond. It is deduced that the NH(2)-terminal undecapeptide of lithostathine normally impedes fiber formation but not aggregation. A theoretical model explaining the formation of amyloid plaques in neurodegenerative diseases or stones in lithiasis starting from lithostathine is described. Therefore we propose that lithostathine, whose major function is unknown, defines a new class of molecules which is activated by proteolysis and is not involved in cytoskeleton nor intermediate filament functions.

Nucleation of calcium oxalate crystals by albumin: involvement in the prevention of stone formation.

BACKGROUND: Urine is supersaturated in calcium oxalate, which means that it will contain calcium oxalate crystals that form spontaneously. Their size must be controlled to prevent retention in ducts and the eventual development of a lithiasis. This is achieved, in part, by specific inhibitors of crystal growth. We investigated whether promoters of crystal nucleation could also participate in that control, because for the same amount of salt that will precipitate from a supersaturated solution, increasing the number of crystals will decrease their average size and facilitate their elimination. METHODS: Albumin was purified from commercial sources and from the urine of healthy subjects or idiopathic calcium stone formers. Its aggregation properties were characterized by biophysical and biochemical techniques. Albumin was then either attached to several supports or left free in solution and incubated in a metastable solution of calcium oxalate. Kinetics of calcium oxalate crystallization were determined by turbidimetry. The nature and efficiency of nucleation were measured by examining the type and number of neoformed crystals. RESULTS: Albumin, one of the most abundant proteins in urine, was a powerful nucleator of calcium oxalate crystals in vitro, with the polymers being more active than monomers. In addition, nucleation by albumin apparently led exclusively to the formation of calcium oxalate dihydrate crystals, whereas calcium oxalate monohydrate crystals were formed in the absence of albumin. An analysis of calcium oxalate crystals in urine showed that the dihydrate form was present in healthy subjects and stone formers, whereas the monohydrate, which is thermodynamically more stable and constitutes the core of most calcium oxalate stones, was present in stone formers only. Finally, urinary albumin purified from healthy subjects contained significantly more polymers and was a stronger promoter of calcium oxalate nucleation than albumin from idiopathic calcium stone formers. CONCLUSIONS: Promotion by albumin of calcium oxalate crystallization with specific formation of the dihydrate form might be protective, because with rapid nucleation of small crystals, the saturation levels fall; thus, larger crystal formation and aggregation with subsequent stone formation may be prevented. We believe that albumin may be an important factor of urine stability.

Evolution of the aminoacyl-tRNA synthetase family and the organization of the Drosophila glutamyl-prolyl-tRNA synthetase gene. Intron/exon structure of the gene, control of expression of the two mRNAs, selective advantage of the multienzyme complex.

In Drosophila, glutamyl-prolyl-tRNA synthetase is a multifunctional synthetase encoded by a unique gene and composed of three domains: the amino- and carboxy-terminal domains catalyze the aminoacylation of glutamic acid and proline tRNA species, respectively, and the central domain is made of 75 amino acids repeated six times amongst which 46 are highly conserved and constitute the repeated motifs [Cerini, C., Kerjan, P., Astier, M., Gratecos, D., Mirande, M. & Sémériva, M. (1991) EMBO J. 10, 4267-4277]. The intron/exon organization of the Drosophila gene reveals the presence of six exons among which four are in the 5'-end encoding glutamic acid activity. Only one exon encodes the repeated motifs. A comparison of introns positions, intron classes and intron/exon boundaries in the Drosophila gene and in its human counterpart is compatible with the intron-early hypothesis presiding, at least in part, to the evolution of the synthetases. The full-length fly protein is encoded by a 6.1-kb mRNA which is expressed throughout development. In addition, a shorter transcript encompasses the 3'-end of the cDNA and it is especially abundant in 5-10-h embryos until the first larval stage. Expression of these two mRNAs seems to be controlled by two independent promoters. The 6.1-kb mRNA promoter is probably localized in the 5'-end of the gene. The small mRNA promoter resides in the 4th intron and evidence is provided that the mRNA encodes only the domain corresponding to prolyl-tRNA synthetase and is functional in vivo. Finally, transgenic flies have been established by using constructs corresponding to the three domains of the protein. Overexpression of the repeated motifs leads to a sterility of the flies that suggests a role of these motifs in linking the multienzyme complex to an, as yet, unknown structure of the protein synthesis apparatus.

Pancreatic lithostathine as a calcite habit modifier.

Most biological fluids are supersaturated with calcium salts. A mechanism controlling crystal growth is therefore necessary to prevent excessive precipitation and development of a lithiasis. In pancreatic juice, calcite precipitation is prevented by lithostathine, a glycoprotein that inhibits calcite crystal growth. We describe here the interaction of lithostathine with calcite crystals. Without lithostathine, calcite crystals grew as rhombohedra showing six (104) faces. At low concentration (1 microM), lithostathine already altered crystal growth by generating new (110) faces. At physiological concentrations (3-10 microM), adsorption resulted in a transition from rhombohedral to sub-cubic habits. Immunochemical localization demonstrated that, although all (104) faces are equivalent, lithostathine binding was restricted to the face edges distal to the c axis. Scanning electron microscopy showed that, at the site of lithostathine binding, spreading of new CaCO3 layers during crystal growth was arrested before reaching the crystal diad axis-bearing edges. The successive kinks generated during crystal growth formed the new, striated (110)faces. Similar modifications were observed with the N-terminal undecapeptide of lithostathine that bears the inhibitory activity. With 100 microM lithostathine, (110) faces could reach the c axis outcrop of the former rhombohedron, resulting in an olive-shaped crystal. Finally, the number of crystals increased and their average size decreased when lithostathine concentration increased from 0.1 to 100 microM. Decreased Ca2+ concentration during crystal growth was delayed in the presence of lithostathine. It was concluded that lithostathine controls lithogenesis 1) by triggering germination of numerous calcite crystals and 2) by inhibiting the rate of Ca2+ ion apposition on the nuclei and therefore interfering with the apposition of new layers on calcite. Formation of smaller crystals, whose elimination is easier, is thereby favored.

The multienzyme complex containing nine aminoacyl-tRNA synthetases is ubiquitous from Drosophila to mammals.

In all mammalian cells studied so far, a multienzyme complex containing the nine aminoacyl-tRNA synthetases specific for the amino acids Glu, Pro, Ile, Leu, Met, Gln, Lys, Arg and Asp was characterized. The complexes purified from various sources display very similar polypeptide compositions; they are composed of 11 polypeptides with molecular masses ranging from 18 to 150 kDa. By contrast, the corresponding enzymes from prokaryotes and lower eukaryotes behave as free enzymes. In order to test for the ubiquity of the multisynthetase complex in all metazoan species, we have searched for a similar complex in Drosophila. We have purified to homogeneity, from Schneider cells, a high molecular weight complex comprising the same nine synthetase activities. Its polypeptide composition resembles that of the complexes isolated from mammalian sources. By using the Western blotting procedure, some of the constituent polypeptides of the Drosophila complex were assigned to specific aminoacyl-tRNA synthetases. These findings support the proposal according to which the multisynthetase complex is an idiosyncratic feature of all higher eukaryotic cells.

Valor diagnostico del dolor abdominal en el tumor desmoide intra-abdominal / Diagnostic value of abdominal pain in intraabdominal desmoid tumor

Desmoid tumors are rare, less than 0,1% of all tumors (6,2%). The word desmoid has been reconized since 1838, and applied to non-encapsulated tumors, of connective origin and locally infiltrative. Generally, their course is painless and the recurrence rate is high if resection has not been complete. Most of these tumors can be found in different anatomic areas, most commonly the anterior abdominal wall although other sites, intra or extraabdominal, have been reported. We describe the case of 50 years old female patient, with abdominal pain caused by an intraabdominal desmoid tumor (AU)

Valor diagnostico del dolor abdominal en el tumor desmoide intra-abdominal / Diagnostic value of abdominal pain in intraabdominal desmoid tumor

Desmoid tumors are rare, less than 0,1% of all tumors (6,2%). The word desmoid has been reconized since 1838, and applied to non-encapsulated tumors, of connective origin and locally infiltrative. Generally, their course is painless and the recurrence rate is high if resection has not been complete. Most of these tumors can be found in different anatomic areas, most commonly the anterior abdominal wall although other sites, intra or extraabdominal, have been reported. We describe the case of 50 years old female patient, with abdominal pain caused by an intraabdominal desmoid tumor

[Diagnostic value of abdominal pain in intra-abdominal desmoid tumor]. / Valor diagnóstico del dolor abdominal en el tumor desmoide intra-abdominal.

Desmoid tumors are rare, less than 0.1% of all tumors (6.2%). The word desmoid has been recognized since 1838, and applied to non-encapsulated tumors, of connective origin and locally infiltrative. Generally, their course is painless and the recurrence rate is high if resection has not been complete. Most of these tumors can be found in different anatomic areas, most commonly the anterior abdominal wall although other sites, intra- or extra-abdominal, have been reported. We describe the case of a 50 year old female patient, with abdominal pain caused by an intraabdominal desmoid tumor.

Valor diagnóstico del dolor abdominal en el tumor desmoide intra-abdominal. / [Diagnostic value of abdominal pain in intra-abdominal desmoid tumor]

Desmoid tumors are rare, less than 0.1

of all tumors (6.2

). The word desmoid has been recognized since 1838, and applied to non-encapsulated tumors, of connective origin and locally infiltrative. Generally, their course is painless and the recurrence rate is high if resection has not been complete. Most of these tumors can be found in different anatomic areas, most commonly the anterior abdominal wall although other sites, intra- or extra-abdominal, have been reported. We describe the case of a 50 year old female patient, with abdominal pain caused by an intraabdominal desmoid tumor.

Valor diagnóstico del dolor abdominal en el tumor desmoide intra-abdominal. / [Diagnostic value of abdominal pain in intra-abdominal desmoid tumor]

Desmoid tumors are rare, less than 0.1

of all tumors (6.2

). The word desmoid has been recognized since 1838, and applied to non-encapsulated tumors, of connective origin and locally infiltrative. Generally, their course is painless and the recurrence rate is high if resection has not been complete. Most of these tumors can be found in different anatomic areas, most commonly the anterior abdominal wall although other sites, intra- or extra-abdominal, have been reported. We describe the case of a 50 year old female patient, with abdominal pain caused by an intraabdominal desmoid tumor.

A component of the multisynthetase complex is a multifunctional aminoacyl-tRNA synthetase.

In higher eukaryotes, nine aminoacyl-tRNA synthetases are associated within a multienzyme complex which is composed of 11 polypeptides with molecular masses ranging from 18 to 150 kDa. We have cloned and sequenced a cDNA from Drosophila encoding the largest polypeptide of this complex. We demonstrate here that the corresponding protein is a multifunctional aminoacyl-tRNA synthetase. It is composed of three major domains, two of them specifying distinct synthetase activities. The amino and carboxy-terminal domains were expressed separately in Escherichia coli, and were found to catalyse the aminoacylation of glutamic acid and proline tRNA species, respectively. The central domain is made of six 46 amino acid repeats. In prokaryotes, these two aminoacyl-tRNA synthetases are encoded by distinct genes. The emergence of a multifunctional synthetase by a gene fusion event seems to be a specific, but general attribute of all higher eukaryotic cells. This type of structural organization, in relation to the occurrence of multisynthetase complexes, could be a mechanism to integrate several catalytic domains within the same particle. The involvement of the internal repeats in mediating complex assembly is discussed.

Immunologic response to the influenza virus neuraminidase is influenced by prior experience with the associated viral hemagglutinin. I. Studies in human vaccinees.

Analysis of an earlier study of H3N2 and H7N2 inactivated influenza vaccines in schoolchildren demonstrated a greater viral neuraminidase (NA) immunogenicity of the vaccine containing the H7 hemagglutinin (HA) antigen to which they had not been primed, despite the lesser NA antigen content of that vaccine. Thus, prior experience with the influenza viral HA appeared to have a negative influence on immune response to NA, the associated external glycoprotein, presumably on the basis of intermolecular antigenic competition. In a second study, sequential immunologic response to influenza viral NA was compared in college students who were immunized with either conventional commercial vaccine or an antigenic reassortant H7N1 vaccine, and who subsequently experienced natural infection with an H1N1 influenza virus. Although both vaccines were only marginally immunogenic in inducing NA antibody response in seronegative subjects, in vaccinees initially seropositive for HA antibody significant NA antibody titer increases occurred with H7N1 vaccine. Subsequent natural infection boosted NA antibody less effectively in the population previously primed by natural infection than in initially seronegative subjects primed by H7N1 vaccination. It is suggested that primary immunization monospecific for influenza viral NA may alter the subsequent pattern of immune response to one more favorable to the induction of NA antibody when virus is encountered.