Assessment of a DJ-1 (PARK7) polymorphism in Finnish PD

Mutations in DJ-1 are a cause of autosomal recessive parkinsonism. Polymorphism of genes implicated in hereditary forms of parkinsonism may be a predisposing factor in sporadic Parkinson's disease (PD). The authors analyzed whether a polymorphism (g.168_185del) within exon 1 of DJ-1 contributes to the risk of sporadic PD in a Finnish case-control series. This gene does not play a major role in the genetic predisposition to PD in this population.

De novo hemolytic-uremic syndrome/thrombotic microangiopathy in renal transplant patients receiving calcineurin inhibitors: role of sirolimus

The aim of this study was to evaluate the outcome of ten renal transplant recipients who developed de novo hemolytic uremic syndrome/thrombotic microangiopathy (DnHUS) after treatment with calcineurin inhibitors among 3,862 patients transplanted during the period 2000-2001 in Spain, and the results of switching to sirolimus for resolution of this pathologic condition. No patient had end-stage disease due to primary HUS. The criteria of diagnosis were decreased renal function, biopsy-proven thrombotic microangiopathy, and no signs of acute rejection. Calcineurin inhibitors were completely removed and immediate treatment with sirolimus started after diagnosis. The follow-up period was 19.0+/-4.3 months, at least 12 months after diagnosis. One patient died of sepsis shortly after starting sirolimus therapy. The serum creatinine level in the series decreased from 5.2+/-2.6 mg/dL at the time of biopsy to 2.15+/-1.9 mg/dL 1 month later (P=.011). All but one of the nine recipients, who lost his graft 3 months later (80% success) maintained function, with a serum creatinine of 2.1+/-1.4 mg/dL and Cockroft index of 61.3+/-34 mL/min at the end of follow up. During this time, none of the patients experienced an acute rejection episode and sirolimus was maintained without any remarkable secondary effect. Sirolimus seems to be a promising alternative for the treatment of renal transplant patients who develop calcineurin inhibitor-induced DnHUS.

Randomised controlled trial of montelukast plus inhaled budesonide versus double dose inhaled budesonide in adult patients with asthma

BACKGROUND

Inhaled corticosteroids (ICS) affect many inflammatory pathways in asthma but have little impact on cysteinyl leukotrienes. This may partly explain persistent airway inflammation during chronic ICS treatment and failure to achieve adequate asthma control in some patients. This double blind, randomised, parallel group, non-inferiority, multicentre 16 week study compared the clinical benefits of adding montelukast to budesonide with doubling the budesonide dose in adults with asthma.

METHODS

After a 1 month single blind run in period, patients inadequately controlled on inhaled budesonide (800 microg/day) were randomised to receive montelukast 10 mg + inhaled budesonide 800 microg/day (n=448) or budesonide 1600 microg/day (n=441) for 12 weeks.

RESULTS

Both groups showed progressive improvement in several measures of asthma control compared with baseline. Mean morning peak expiratory flow (AM PEF) improved similarly in the last 10 weeks of treatment compared with baseline in both the montelukast + budesonide group and in the double dose budesonide group (33.5 v 30.1 l/min). During days 1-3 after start of treatment, the change in AM PEF from baseline was significantly greater in the montelukast + budesonide group than in the double dose budesonide group (20.1 v 9.6 l/min, p<0.001), indicating faster onset of action in the montelukast group. Both groups showed similar improvements with respect to "as needed" beta agonist use, mean daytime symptom score, nocturnal awakenings, exacerbations, asthma free days, peripheral eosinophil counts, and asthma specific quality of life. Both montelukast + budesonide and double dose budesonide were generally well tolerated.

CONCLUSION

The addition of montelukast to inhaled budesonide is an effective and well tolerated alternative to doubling the dose of inhaled budesonide in adult asthma patients experiencing symptoms and inadequate control on budesonide alone.

Efficacies of entecavir against lamivudine-resistant hepatitis B virus replication and recombinant polymerases in vitro

Entecavir (ETV) is a potent and selective inhibitor of hepatitis B virus (HBV) replication in vitro and in vivo that is currently in clinical trials for the treatment of chronic HBV infections. A major limitation of the current HBV antiviral therapy, lamivudine (3TC), is the emergence of drug-resistant HBV in a majority of treated patients due to specific mutations in the nucleotide binding site of HBV DNA polymerase (HBV Pol). To determine the effects of 3TC resistance mutations on inhibition by ETV triphosphate (ETV-TP), a series of in vitro studies were performed. The inhibition of wild-type and 3TC-resistant HBV Pol by ETV-TP was measured using recombinant HBV nucleocapsids, and compared to that of 3TC-TP. These enzyme inhibition studies demonstrated that ETV-TP is a highly potent inhibitor of wild-type HBV Pol and is 100- to 300-fold more potent than 3TC-TP against 3TC-resistant HBV Pol. Cell culture assays were used to gauge the potential for antiviral cross-resistance of 3TC-resistant mutants to ETV. Results demonstrated that ETV inhibited the replication of 3TC-resistant HBV, but 20- to 30-fold higher concentrations were required. To gain further perspective regarding the potential therapeutic use of ETV, its phosphorylation was examined in hepatoma cells treated with extracellular concentrations representative of drug levels in plasma in ETV-treated patients. At these concentrations, intracellular ETV-TP accumulated to levels expected to inhibit the enzyme activity of both wild-type and 3TC-resistant HBV Pol. These findings are predictive of potent antiviral activity of ETV against both wild-type and 3TC-resistant HBV.

Contribution of APOE promoter polymorphisms to Alzheimer's disease risk

OBJECTIVE

To determine whether the effects of APOE promoter polymorphisms on AD are independent of the APOE-epsilon4 allele.

BACKGROUND

Recently, the -491 A-->T and -219 G-->T polymorphisms located in the APOE promoter have been suggested to be risk factors for AD. However, the effects of these polymorphisms have not always been reproduced in case-control studies, possibly because of the strong linkage disequilibrium existing at this locus or the characteristics of the populations studied.

METHODS

Data collection was performed from six independent samples (1,732 patients with AD and 1,926 control subjects) genotyped for APOE exon 4 and the two APOE promoter polymorphisms. The risks associated with the APOE polymorphisms for developing AD were estimated using logistic regression procedures and calculation of odds ratios with 95% CI adjusted by age, sex, and collection center. Independence of the APOE promoter polymorphisms was tested by stratification for APOE-epsilon4 and tertile design was used for age stratification.

RESULTS

The independence of the -491 AA genotype was observed in the whole sample whereas the independence of the -219 TT genotype was observed only in the oldest population.

CONCLUSION

The -491 and -219 APOE promoter polymorphisms incur risk for AD in addition to risk associated with the APOE-epsilon4 allele, with age accentuating the effect of the -219 TT genotype. Because these polymorphisms appear to influence apoE levels, these results suggest that APOE expression is an important determinant of AD pathogenesis.

Pilot-scale process sensitivity studies for the scaleup of a fungal fermentation for the production of pneumocandins

The filamentous fungus Glarea lozoyensis produces a novel, pharmaceutically important pneumocandin (B(0)) that is used to synthesize a lipopeptide which demonstrates cidal activity against clinically relevant pathogens. A range of unwanted pneumocandin analogs are also produced by the organism. To maintain the unwanted impurities to acceptable levels upon scaleup, a good understanding of the impact of chemical and physical environment on the cell physiology is required, which benefits downstream processing. Pilot-scale studies were performed to determine the impact of dissolved oxygen, temperature, pH, and carbon dioxide on the process. Experiments included multiple fermenters (up to seven) at 0.07 and 0.8 m(3) scale using single source medium sterilization and inoculum. Gas blending was used to separate effects of dissolved oxygen from agitation. The process was significantly influenced by dissolved oxygen level. The critical dissolved oxygen tension (C(crit)) for growth was below 2% air saturation. The C(crit) for production of pneumocandin B(0) was 20% air saturation, with a significant reduction of the specific production rate below this value. In contrast, low dissolved oxygen levels produced a substantial increase of pneumocandins B(1), B(5), and E(0), while high dissolved oxygen levels produced a disproportionate increase of D(5). This sensivity to dissolved oxygen was independent of agitation within a power range of 2-15 kW/m(3). Broth viscosity was impacted below 10% dissolved oxygen, suggesting an effect on morphology. The process was shown to be sensitive to temperature but relatively insensitive to pH and carbon dioxide (in the exhaust gas) within the ranges studied. This scaledown analysis explained phenomena seen at pilot scale and helped define operating boundary conditions for successful scale up to 19 m(3).

Calcineurin inhibitors and post-transplant hyperlipidaemias

Cardiovascular disease is now the leading cause of death in transplant recipients. This is due, in part, to the vulnerability of these patients to a complicated set of conditions including hypertension, diabetes mellitus, and post-transplant hyperlipidaemia (PTHL). PTHL is characterised by persistent elevations in total serum cholesterol, low density lipoprotein cholesterol and triglyceride levels. The causes of PTHL are complex and not fully understood, however several classes of immunosuppressants including the corticosteroids, rapamycins and calcineurin inhibitors, appear to play a role. PTHL has been observed in most studies in which patients received calcineurin inhibitor-based regimens, and has been observed with both tacrolimus and cyclosporin. Comparing these calcineurin inhibitors with regard to the relative incidence or severity of PTHL occurring during treatment is difficult because of the use of higher doses of corticosteroids in cyclosporin-based regimens, as compared with tacrolimus-based regimens. However, current expert opinion suggests that the discrepancies in the relative incidence and severity of PTHL are largely accounted for by this difference in corticosteroid dose. At this point in time, evidence for potential differences is scant and inconclusive. Further study is needed, not only to investigate differences in lipid profile, but also of the relative effects of these immunosuppressants on long term graft function as well as on cardiovascular morbidity and mortality. PTHL can be successfully managed with a combination of dietary management, reduction and, if appropriate, withdrawal of corticosteroids, and the administration of lipid-lowering drugs. With this combination of therapeutic options, the threats to long term health posed by PTHL may be effectively addressed.

Complementary spiritual beliefs in the Latino community: the interface with psychotherapy

A model involving a dynamic spectrum of belief by Latinos in the spiritual traditions of Santeria and Espiritismo is proposed as replacement for the more static prevalence model. The issue of clinical responsiveness to such material is examined and illustrated, and implications for research and practice are discussed.

Structure-activity relationship studies of a bisbenzimidazole-based, Zn(2+)-dependent inhibitor of HCV NS3 serine protease

A survey of isosteric replacements of the phosphonoalanine side chain coupled with a process of conformational constraint of a bisbenzimidazole-based, Zn(2+)-dependent inhibitor of hepatitis C virus (HCV) NS3 serine protease resulted in the identification of novel series of active compounds with extended side chains. However, Zn(2+)-dependent HCV NS3 inhibition was relatively insensitive to the structural variations examined but dependent on the presence of negatively charged functionality. This result was interpreted in the context of an initial electrostatic interaction between protease and inhibitor that is subsequently consolidated by Zn(2+), with binding facilitated by the featureless active site and proximal regions of the HCV NS3 protein.

Lewy bodies and parkinsonism in families with parkin mutations

Previous work has established that compound mutations and homozygous loss of function of the parkin gene cause early-onset, autosomal recessive parkinsonism. Classically, this disease has been associated with loss of dopaminergic neurons in the substantia nigra pars compacta and locus ceruleus, without Lewy body pathology. We have sequenced the parkin gene of 38 patients with early-onset Parkinson's disease (<41 years). Two probands with mutations were followed up. Clinical evaluation of their families was performed, blinded to both genetic and pathological findings. Chromosome 6q25.2-27 haplotype analysis was carried out independently of the trait; parkin gene expression was examined at both the RNA and protein levels. Haplotype analysis of these families revealed a common chromosome 6, with a novel 40 bp exon 3 deletion that cosegregated with disease. In the proband of the smaller kindred, an exon 7 R275W substitution was identified in addition to the exon 3 deletion; RNA analysis demonstrated that the mutations were on alternate transcripts. However, Lewy body pathology typical of idiopathic Parkinson's disease was found at autopsy in the proband from the smaller kindred. These data suggest that compound heterozygous parkin mutations and loss of parkin protein may lead to early-onset parkinsonism with Lewy body pathology, while a hemizygous mutation may confer increased susceptibility to typical Parkinson's disease.

alpha-Synuclein gene haplotypes are associated with Parkinson's disease

We report haplotype analysis of the alpha-synuclein gene in Parkinson's disease (PD), extending earlier reports of an association with a polymorphism within the gene promoter. This analysis showed significant differences in haplotypes between PD cases and controls. Our analyses demonstrate that genetic variability in the alpha-synuclein gene is a risk factor for the development of PD. These genetic findings are analogous to the tau haplotype over-represented in progressive supranuclear palsy and further extend the similarity in the etiologies and pathogeneses of the synucleinopathies and tauopathies.

Aggression and psychiatric comorbidity in children with hypothalamic hamartomas and their unaffected siblings

OBJECTIVE

To assess aggression and psychiatric comorbidity in a sample of children with hypothalamic hamartomas and gelastic seizures and to assess psychiatric diagnoses in siblings of study subjects.

METHOD

Children with a clinical history of gelastic seizures and hypothalamic hamartomas (n = 12; age range 3-14 years) had diagnoses confirmed by video-EEG and head magnetic resonance imaging. Structured interviews were administered, including the Diagnostic Interview for Children and Adolescents-Revised Parent Form (DICA-R-P), the Test of Broad Cognitive Abilities, and the Vitiello Aggression Scale. Parents were interviewed with the DICA-R-P about each subject and a sibling closest in age without seizures and hypothalamic hamartomas. Patients were seen from 1998 to 2000.

RESULTS

Children with gelastic seizures and hypothalamic hamartomas displayed a statistically significant increase in comorbid psychiatric conditions, including oppositional defiant disorder (83.3%) and attention-deficit/hyperactivity disorder (75%). They also exhibited high rates of conduct disorder (33.3%), speech retardation/learning impairment (33.3%), and anxiety and mood disorders (16.7%). Significant rates of aggression were noted, with 58% of the seizure patients meeting criteria for the affective subtype of aggression and 30.5% having the predatory aggression subtype. Affective aggression was significantly more common (p < .05). Unaffected siblings demonstrated low rates of psychiatric pathology on semistructured parental interview and no aggression as measured by the Vitiello Aggression Scale.

CONCLUSIONS

Children with hypothalamic hamartomas and gelastic seizures had high rates of psychiatric comorbidity and aggression. Parents reported that healthy siblings had very low rates of psychiatric pathology and aggression.

Survival and plasticity of basal forebrain cholinergic systems in mice transgenic for presenilin-1 and amyloid precursor protein mutant genes

The basalo-cortical cholinergic system was characterized in mice expressing mutant human genes for presenilin-1 (PS1), amyloid precursor protein (APP), and combined PS/APP. Dual immunocytochemistry for ChAT and A beta revealed swollen cholinergic processes within cortical plaques in both APP and PS/APP brains by 12 months, suggesting aberrant sprouting or redistribution of cholinergic processes in response to amyloid deposition. At 8 months, cortical and subcortical ChAT activity was normal (PS/APP) or elevated (PS, APP frontal cortex), while cholinergic cell counts (nBM/SI) and receptor binding were unchanged. ChAT mRNA was up-regulated in the nBM/SI of all three transgenic lines at 8 months. The data indicate that the basal forebrain cholinergic system does not degenerate in mice expressing AD-related transgenes, even in mice with extreme amyloid load. The

Genetic analysis of synphilin-1 in familial Parkinson's disease

alpha-Synuclein is present in Lewy bodies of patients with both sporadic and familial Parkinson's disease. However, pathogenic mutations Ala30Pro and Ala53Thr in alpha-synuclein are rare causes of disease. Synphilin-1 has been demonstrated to associate with alpha-synuclein and promote the formation of cytosolic inclusions in vitro. Two-point genetic linkage analysis of a dinucleotide repeat within the synphilin-1 gene initially implicated this locus as a cause of Parkinson's disease in three of nine families. However, subsequent haplotype, sequencing, and association analyses in these three families and an independent case-control series suggest that variability within the locus does not confer susceptibility to Parkinson's disease.

Application of the multilingual aphasia examination-spanish in the evaluation of Hispanic patients post closed-head trauma

Despite the rapid increase of Hispanics in the U.S., there continues to be a lack of adequate psychological assessment tools to examine Spanish-speaking patients with cognitive or neuropsychological disturbances. We investigated the clinical utility of the Multilingual Aphasia Examination-Spanish (MAE-S) in the evaluation of language functions of Hispanic subjects post-traumatic brain injury (TBI). The performance of 40 TBI patients was compared to that of 40 age-, gender-, and education-matched normal controls. Subject groups differed on the Visual Naming (VN), Controlled Oral Word Association (COWA), and Token Test subtests. The VN and COWA subtests were the best discriminators of group membership. Distribution of scores for the patient group on the Rating of Articulation scale additionally indicate subtle articulatory difficulties post-TBI. For all subtests, trauma severity per Glasgow Coma Scale was the best predictor of language performance, over and above the contribution of other clinical and demographic variables. These results are consistent with prior reports of dysphasia post-TBI and suggest that the MAE-S is a sensitive and accurate measure to assess language disturbances in Hispanic populations.

Proteoglycan metabolism during repair of the ruptured medial collateral ligament in skeletally mature rabbits

The metabolism of the chondroitin/dermatan sulfate (CS/DS) proteoglycans (PGs) decorin and biglycan is markedly altered during short-term (3-6 weeks) and long-term (40 weeks-2 years) repair of surgically ruptured medial collateral ligaments from mature rabbits. A PG-rich extracellular matrix accumulates in injury gaps by 3 weeks postsurgery and extends into tissue regions containing the original ligaments, and elevated PG levels remain apparent up to 2 years postinjury. CS/DS PGs were prepared from such ligaments and identified after SDS-polyacrylamide gel electrophoresis by Alcian blue staining or immunoblotting. In normal ligaments, decorin is the most abundant proteoglycan (accounting for approximately 80% of the total); the remainder is biglycan and a large PG, possibly versican. In repairing ligaments, decorin is barely detected, but instead a large proteoglycan and abundant amounts of biglycan accumulate. Biglycan is present in two forms in repairing ligaments, and they can be separated on SDS-PAGE into 200- and 140-kDa forms. The slower migrating species is absent in normal ligaments and may represent a different glycoform (containing either a single or two short chondroitin/dermatan sulfate chains) of biglycan. Alteration in PG expression and posttranslational processing during medial collateral ligament repair are similar to those reported for repair and scar formation of other connective tissues. The accumulation of biglycan observed here may interfere with proper collagen network remodeling and may lead to persistent inflammatory and matrix turnover processes, thus preventing restoration of a long-term functional ligament tissue.

Recipient factors as determinants of mortality after adult liver transplantation

The factors that can influence the outcome of orthotopic liver transplantation (OLT) are numerous. The purpose of this study was to determine the effects of recipient preoperative factors on patient mortality. Between April 1986 and April 1998 a total of 600 OLTs were performed in our institution. We retrospectively reviewed our first 203 consecutive primary adult OLTs with at least 4 years of follow-up. A case-control comparison was performed between survivors and nonsurvivors, and differences in recipient variables were studied for their correlation with patient mortality. A logistic regression analysis was also performed. Mortality was significantly increased among those with fulminant hepatic failure (FHF) (66.6%, p = 0.003), primary cancer (63.1%, p = 0.018), females (46.1%, p = 0. 043), encephalopathy grade IV (72.7%, p = 0.012), recipients under respiratory support (69.2%, p = 0.031), and ABO-incompatible transplants (80%, p = 0.05). FHF, primary cancer, and female gender were the only variables that had a significant association with mortality in the logistic regression analysis. A higher incidence of prolonged respiratory support, bacterial and fungal infections, pneumonia, and chronic rejection contributed to the lower outcome observed in females. These results stress the need for continuous evaluation of the selection criteria of candidates for OLT suffering from primary cancer and FHF. The impact of recipient gender on mortality warrants further analysis but suggests that in the future more attention must be paid to the influence of this factor on the final outcome of OLT.

Mouse autosomal trisomy: two's company, three's a crowd

Autosomal trisomy causes a large proportion of all human pregnancy loss and so is a significant source of lethality in the human population. The autosomal trisomy syndromes each have a different phenotype and are probably caused by the effects of specific genes that are present in three copies, rather than the normal two. Identifying these genes will require the application of classical genetic and new genome-manipulation approaches. Recent advances in chromosome engineering are now allowing us to create precisely defined autosomal trisomies in the mouse, and so provide new routes to identifying the critical, dosage-sensitive genes that are responsible for these highly deleterious, yet very common, syndromes.

Transchromosomal mouse embryonic stem cell lines and chimeric mice that contain freely segregating segments of human chromosome 21

At least 8% of all human conceptions have major chromosome abnormalities and the frequency of chromosomal syndromes in newborns is >0.5%. Despite these disorders making a large contribution to human morbidity and mortality, we have little understanding of their aetiology and little molecular data on the importance of gene dosage to mammalian cells. Trisomy 21, which results in Down syndrome (DS), is the most frequent aneuploidy in humans (1 in 600 live births, up to 1 in 150 pregnancies world-wide) and is the most common known genetic cause of mental retardation. To investigate the molecular genetics of DS, we report here the creation of mice that carry different human chromosome 21 (Hsa21) fragments as a freely segregating extra chromosome. To produce these 'transchromosomal' animals, we placed a selectable marker into Hsa21 and transferred the chromosome from a human somatic cell line into mouse embryonic stem (ES) cells using irradiation microcell-mediated chromosome transfer (XMMCT). 'Transchromosomal' ES cells containing different Hsa21 regions ranging in size from approximately 50 to approximately 0.2 Mb have been used to create chimeric mice. These mice maintain Hsa21 sequences and express Hsa21 genes in multiple tissues. This novel use of the XMMCT protocol is applicable to investigations requiring the transfer of large chromosomal regions into ES or other cells and, in particular, the modelling of DS and other human aneuploidy syndromes.

The human immunodeficiency virus-1 Tat protein increases cell proliferation, alters sensitivity to zinc chelator-induced apoptosis, and changes Sp1 DNA binding in HeLa cells

The HIV-1 transcriptional regulatory protein Tat is a pleiotropic factor that represses expression of the human Mn-superoxide dismutase. Tat increases oxidative stress, as shown by decreased glutathione and NADPH levels. These redox changes enhance proliferation and apoptosis and alter the activity of zinc thiolate-containing proteins such as Sp1. Cells stably producing the Tat protein have an increased proliferation rate, which can be inhibited by pretreatment with the antioxidant mercaptopropionylglycine. Conversely, cells exposed to low concentrations of the oxidant paraquat are stimulated to divide. Intermediate and higher paraquat levels result in increased apoptosis or necrosis, respectively, suggesting that the physiological end point depends on the dose of oxidant used. Furthermore, treatment with the zinc chelator (N,N,N', N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) sensitizes HeLa-tat cells to apoptosis. In these cells, binding of the zinc-containing factor Sp1 to its DNA sequence is higher than in parental cells. Normal DNA binding is partially restored by pretreatment with a compound that mimics superoxide dismutase activity. Interestingly, Sp1-DNA interactions decrease more rapidly in the HeLa-tat cells after TPEN treatment. HeLa cell extracts incubated in the presence of purified Tat protein have increased Sp1 binding, consistent with the results observed in Tat-transfected cells. These results suggest that the Tat protein, via direct or indirect mechanisms, increases proliferation, sensitizes cells to apoptosis, and changes the conformation of Sp1, affecting its ability to bind to its cognate DNA sequence and to retain its zinc.

Amoebological study of the atmosphere of San Luis Potosi, SLP, Mexico

A one year round survey was conducted for isolation of free living amoebae (FLA) in the city of San Luis Potosi, (SLP), Mexico, which is placed in a desert environment. Samples were taken by modified impinger method and cultivated in laboratory conditions for FLA isolation following a week period of rehidration. 57 strains were isolated, 39% belonged to Acanthamoeba genus (which is important because it bears opportunistic pathogens that produce amoebic keratitis and granulomatous amoebic encephalitis in humans), 16% to Hartmannella, 9% to Vahlkampfia and the other proportion was divided among 6 other genera. The isolations were more abundant during dry season and the main genera were present in all four stands. The difference among them was the species variety which is discused as connected with abundance of organic wastes and lack of urbanization near the stations.

Three-dimensional vascular imaging using Doppler ultrasound

BACKGROUND

We have evaluated the efficacy of using three-dimensional reconstruction of amplitude Doppler imaging data to quantitatively assess carotid artery bifurcation stenoses.

METHODS

Sixty-four consecutive frames of amplitude (power) Doppler images are stored to be reassembled into a three-dimensional image representing the patent lumen. These images can then be rotated by any angle necessary to clearly view the vascular anatomy and to make quantitative ultrasound caliper measurements of the stenotic lumen and normal vessel caliber.

RESULTS

Three-dimensional Doppler images accurately classified 53 of 61 vessels (87%) into categories of stenosis compared with angiography. All stenoses with >60% diameter reduction were detected and classified as such, for a sensitivity of 100%.

CONCLUSIONS

Three-dimensional vascular imaging based on amplitude (power) Doppler data provides an accurate noninvasive technique for quantitative diagnosis of carotid bifurcation atherosclerotic disease, with selectable viewing projections that eliminate vessel overlap and other artifacts, and complements the hemodynamic data already available with two-dimensional duplex ultrasound.

Crystallization and preliminary X-ray studies of Pseudomonas putida histidine ammonium-lyase

Histidine ammonium-lyase from P. putida was expressed in Escherichia coli, purified to homogeneity, and crystallized by the vapour-diffusion method using polyethylene glycol 3350 as the precipitant. The crystals, which diffract to at least 2.5 A resolution, exhibit the symmetry of space group P212121, with unit-cell parameters a = 89.7, b = 138.2 and c = 164.8 A. The asymmetric unit contains a tetramer, and the crystals have a Vm value of 2.41 A3 Da-1.

Down syndrome genetics: unravelling a multifactorial disorder

Down syndrome is a common disorder affecting many tissues both during development and later on in adult life; the principle feature of all cases is a specific form of mental retardation, which is combined with a range of variable traits. Down syndrome is an aneuploidy syndrome that is caused by trisomy for human chromosome 21. While the phenotype is most likely due to a subtle increase in gene dosage of only a small minority of the estimated 500-800 genes that are present on this chromosome, the molecular genetics of Down syndrome remains speculative. However, recent advances on a number of fronts, including chromosome studies, gene identification and mouse modelling, are giving us the tools to dissect this multifactorial gene dosage disorder.

HLA-DR class II and ICAM-1 expression on tubular cells taken by fine-needle aspiration biopsy in renal allograft dysfunction

BACKGROUND

Percutaneous biopsy is the method of choice for differential diagnosis of renal allograft dysfunction, although it is not risk-free. The use of less aggressive methods for diagnosis should limit the need for percutaneous biopsy to some specific situations.

METHODS

We analysed 42 fine-needle aspiration biopsies from 36 kidney allograft recipients immunosuppressed with quadruple sequential therapy who suffered renal allograft dysfunction. Seven cases with stable renal function were used as controls and included as non-rejection cases in the analysis. In all aspirates the Corrected Increment was calculated and an immunocytochemical analysis of renal tubular cells with the monoclonal antibodies HLA-DR and ICAM-1 was performed.

RESULTS

The Corrected Increment was increased in 13 out of 18 acute rejection cases and in one out of 31 non-rejection cases. HLA-DR expression was found in more than 30% of tubular cells from the aspirates in 16 out of 18 acute rejection cases and in eight out of 31 cases without rejection (P < 0.001). ICAM-1 expression was detected in more than 30% of tubular cells in 14 out of 18 cases with acute rejection, and in four out of 31 cases without acute rejection (P < 0.001). Interestingly, all acute vascular rejection cases (n = 6), and six out of 12 acute cellular rejection cases expressed both, HLA-DR and ICAM-1, in more than 30% of tubular cells. On the other hand, none of the non-rejection allograft dysfunctions or control samples showed more than 30% of tubular cells immunostained with both HLA-DR and ICAM-1 antibodies.

CONCLUSIONS

The immunocytochemical analysis of HLA-DR and ICAM-1 on renal tubular cells taken by fine-needle aspiration biopsy, allows the diagnosis of acute cellular rejection and acute vascular rejection even when the Corrected Increment is not increased. Moreover, the risk of a core renal biopsy can be avoided when both tests are negative since an acute rejection is a remote possibility.

Establishment of an in vitro assay to characterize hepatitis C virus NS3-4A protease trans-processing activity

An in vitro cleavage system was established to measure HCV NS3 protease trans-processing activity. This system utilizes purified NS3-4A protein from baculovirus, purified substrates expressed by in vitro transcription and translation and defined buffer components. The 41-residue substrates, 5A/5B and 4A/4B, were processed efficiently in trans by wild-type NS3 but not by a catalytically inactive mutant protease; radiolabel sequencing confirmed that NS3-mediated cleavage occurred at the correct cysteine/serine sites, thereby authenticating this system. Two striking features of this in vitro assay are: (1) analogous 4B/5A and 3/4A substrates cannot be processed in trans under the same conditions, and (2) in vitro cleavage of the 5A/5B and 4A/4B sites is highly dependent on the presence of NS4A, which we show is not the case in vivo.

Mapping TNNC1, the gene that encodes cardiac troponin I in the human and the mouse

We have mapped the TNNC1 gene, whose protein product is the cardiac TnI protein. TnI is one of the proteins that makes up the troponin complex, which mediates the response of muscle to calcium ions. The human TNNC1 locus had been assigned to a large region of chromosome 19, and we have refined the mapping position to the distal end of the chromosome by amplification of DNAs from a chromosome 19 mapping panel. We have also mapped the mouse Tnnc1 locus, by following the segregation of an intron sequence through DNAs from the European Interspecific Backcross. Tnnc1 maps close to the centromere on mouse chromosome 7.

Characterization of an optical-fiber reflectometer for in situ measurement applications

We present studies of apparatus based on optical-fiber probes for measuring the reflectivity of opaque materials. The probes are designed for in situ applications at high temperatures and in situations for which access is difficult. First, we present a method in which the hemispherical reflectivity and the angular distribution of the reflected flux are obtained from bidirectional measurements. Second, we describe a method to measure the reflectivity in only the normal direction; this method is available only for diffuse materials. Both methods of use of the device were validated through the use of commercial diffuse standards and specific materials with particular surface microstructures.

[Rectal biopsies from HIV-infected patients]

Rectosigmoidoscopy and rectal biopsies specimens were taken from thirty six HIV infected patients in the Vargas Hospital of Caracas. There were thirty three males and three females. the mean age was thirty two years. Seventy three per cent were homosexuals. The sexual behaviour was the most important risk factor for the infection with the HIV. Forty four per cent of the rectosigmoidoscopies were abnormal, presenting hiperemic or petechiae mucosas. Alterations in rectal biopsies were reported on all specimens, twenty six with inespecific chronic rectitis. Two bipsies reported Kaposi's Sarcoma and eight bipsies demonstrated opportunistic agents.

Highly polymorphic sequence at D21S1448 mapping close to D21S55, within the Down syndrome critical region

We have isolated a highly polymorphic sequence from the Down syndrome critical region on human chromosome 21. This is a particularly useful marker because it lies adjacent to the locus D21S55, which is most closely associated with the major defects on Down syndrome. Other than this marker, few other variable sequences are known in this region (including other restriction fragment length polymorphisms or CA repeats) and therefore D21S1448 will be extremely helpful not only for people studying the inheritance of portions of chromosome 21 with respect to Down syndrome, but also for those carrying out linkage analysis of the chromosome.

In vitro autonomous proliferation in ANLL: clinical and biological significance

In acute non-lymphoblastic leukemia (ANLL) progenitor cells frequently display a certain degree of autonomous growth. The aim of the present work was to analyze the autonomous proliferative capacity of leukemic progenitors in both de novo and secondary to myeloproliferative disorders (MPD) and myelodysplastic syndromes (MDS), acute myeloid leukemias and to correlate with clinical and biological characteristics of the disease. Clonogenic assays with and without leukocyte conditioned medium with PHA (LCM-PHA) were performed and the autonomous proliferation index (API) calculated in a series of 50 patients (34 de novo ANLL, eight secondary to MPD and eight secondary to MDS). Patients were divided into two groups according to their API, low (< or = 0.4) or high (> 0.4). Autonomous growth was observed in 84% of cases studied (82% in de novo ANLL, 75% secondary to MDS and 100% secondary to MPD). The group with the highest API (29 patients) had increased levels of hemoglobin (P = 0.006) and platelets (P = 0.01). A high API was also associated with an immature phenotype of blast cells (P = 0.02). Upon analyzing the de novo ANLL separately we observed that a high API correlated with high Hb values (P = 0.02), a lower rate of complete remission (42% vs 61%) and a lower survival rate (medium of 3 vs 10 months). These findings suggest that the capacity for autonomous proliferation can condition the clinical and biological profile of the disease.

Effect of chewing gums on plaque pH after a sucrose challenge

The objective of this study was to determine whether sugarless chewing gums sweetened with different sweeteners differ in their ability to reduce an acidogenic response from a 10 percent sucrose-rinse challenge. Five commercially available chewing gums and two control regimens ("no gum" or paraffin) were tested using a plaque pH telemetry system. The gums were sweetened with sucrose, high-intensity sweeteners (aspartame, saccharin, or acesulfame-K), or a polyol (xylitol). Using a seven-period randomized block design, eight adult panelists were challenged with a 10 percent sucrose solution and then randomly used one of the test regimens during each of the seven test sessions. Each two-hour test session was divided into five periods: resting baseline (five minutes); sucrose rinse challenge (two minutes); postsucrose challenge (ten minutes); gum chewing (ten minutes); post gum chewing (ninety-three minutes). The factors analyzed were: the area of the curve (pH X Time) below pH 5.5, the minimum plaque pH attained, the changes in plaque pH over relevant intervals, and the length of time the plaque pH remained below pH 5.5. The various response variables showed a similar pattern of statistically significant differences. All of the sugarless gums were effective in significantly increasing plaque pH and in reducing the area under the curve after the sucrose challenge compared with "no gum" treatment. No statistically significant differences were noted among the sugarless gums. The response to sucrose gum was intermediate between sugarless gums and "no gum" but was not statistically different from "no gum" or three of the sugarless gums.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular basis of drug phototoxicity: photosensitized cell damage by the major photoproduct of tiaprofenic acid

Tiaprofenic acid is a photosensitizing nonsteroidal anti-inflammatory drug, whose major photoproduct (decarboxytiaprofenic acid) is also a potent photosensitizer. Because of the lack of the carboxylate moiety, this photoproduct is more lipophilic and might bind more efficiently to cell membranes, thereby causing phototoxic damage. To verify the feasibility of this hypothesis, we have prepared the 3H-labeled analogs of tiaprofenic acid and its photoproduct and examined the binding, persistence and phototoxicity of the photoproduct using poorly metabolizing (fibroblasts) and actively metabolizing cells (hepatocytes). The photoproduct of tiaprofenic acid accumulates in both cell types as it is formed. Upon removal of the photoproduct from the culture medium, it rapidly disappears from hepatocytes but not from fibroblasts. Consequently, irradiation of fibroblasts previously incubated with the photoproduct and kept in culture in the dark for 20 h results in generalized cell damage while this effect is not observed in hepatocytes. Because of its long persistence in poorly metabolizing skin cells and its reluctance to photobleaching, the formation of this photoproduct in skin may be of relevance to explain the in vivo phototoxicity of tiaprofenic acid.

Mapping the gene that encodes phosphatidylinositol-specific phospholipase C-gamma 2 in the human and the mouse

We have mapped the PLCG2 gene, which encodes the enzyme phosphatidyl inositol-specific phospholipase C-gamma 2. This is one of the phospholipases responsible for catalyzing the hydrolysis of phosphatidyl inositol in response to a great many mitogenic stimuli. PL C-gamma 2 is an essential component of the signal transduction pathway between tyrosine kinases and downstream events such as protein kinase C activation and intracellular calcium release. We assigned PLCG2 to human chromosome 16 by amplification within a somatic cell hybrid mapping panel. To position the locus at a much finer resolution, PLCG2 sequences were amplified from a chromosome 16-specific somatic cell hybrid panel, which placed the gene on the long arm of the chromosome in band 16q24.1, a region that has few known genes. We have hybridized a mouse Plcg2 open reading frame probe to mouse DNAs from the European Interspecific Backcross. The segregation pattern reveals the mouse Plcg2 locus maps to distal chromosome 8.

Influence of high temperatures on a fiber-optic probe for temperature measurement

The use of optical fiber in a temperature probe or sensor for optical pyrometry in the 100-1000 °C range is affected by the low thermal stability of classical fibers. We have studied the different sources of perturbations induced by exposure to high temperature. Two specific fibers especially suited for a high-temperature environment were tested and compared. Low (100 °C/min) and very fast (100 °C/s) fiber heating was performed to evaluate its influence on the guided flux and the induced error on temperature measurement. The metallic-coated fiber shows a reproducible temperature error that can be predicted. This important result permits the development of an uncooled fiber probe for temperature monitoring in high-temperature environments such as aerospace engines.

Ser-143 is an essential active site residue in histidine ammonia-lyase of Pseudomonas putida

Site directed mutagenesis was used to investigate the role of Ser-143 in enzyme activity and as a point for attack by cyanide or L-cysteine, two irreversible inhibitors of histidine ammonia-lyase (histidase). Two mutant proteins, a S143A substitution and an A142S-S143A transposition, were made. Both mutant histidases completely lost all enzymatic activity. Western blots with anti-histidase antibodies revealed that the mutant proteins were being expressed at a level equal to that of the wild-type protein. The purified mutant proteins could not incorporate [14C]cyanide nor could they generate the UV-absorbing species normally observed when L-cysteine modifies wild-type histidase. These results support the hypothesis that Ser-143 is the binding site for an as yet unidentified histidase cofactor.

Adynamic bone disease with negative aluminium staining in predialysis patients: prevalence and evolution after maintenance dialysis

Aplastic bone disease (ABD) is a common form of renal osteodystrophy and is characterized by a defect in bone matrix formation and mineralization without an increase in osteoid thickness. The prevalence and pathogenesis of ABD in predialysis patients is largely unknown. We prospectively studied 92 unselected predialysis patients with a creatinine clearance < 10 ml/min/1.73 m2 and a mean age of 45 +/- 2 years (61 M, 31 F). None of the study patients had received any form of vitamin D therapy, and CaCO3 was the primary phosphate binder. Aplastic bone disease was observed in 30 (32%) patients. Stainable bone aluminium surface was < 3% in all ABD patients. Patients with ABD were older (52 +/- 3 versus 42 +/- 2 years; P < 0.01) and had reduced serum intact PTH compared to non-ABD patients (199 +/- 25 versus 561 +/- 87 pg/ml; P < 0.001). Patients with diabetes mellitus showed lower PTH values (179 +/- 31 versus 432 +/- 62 pg/ml; P < 0.001) and a lower incidence of advanced hyperparathyroidism bone lesions (16% versus 46%; P < 0.05) than non-diabetic patients. However, diabetes was not clearly associated with low bone turnover disease (56% in diabetics versus 41% in non-diabetics; P = 0.1). A second bone biopsy was obtained in eleven ABD patients after a period of 16.6 +/- 2.2 months on maintenance dialysis with a dialysate calcium of 7 mg/dl. Bone histology was unchanged in 10 patients, and one evolved to mild hyperparathyroidism. Trabecular bone volume did not change (22.7 +/- 1.7 versus 20.7 +/- 1.7%), and the stainable bone aluminium surface remained < 3%.(ABSTRACT TRUNCATED AT 250 WORDS)

[The importance of children for the elderly and changes in reproductive behavior (a study of three rural communities in Mexico)]

"This study analyzes the importance of children in the care of elderly populations in rural communities [in Mexico].... In particular, the perception of elders about the value of their children is analyzed, especially the role children play in their economic contribution to the household or their instrumental value to it at different stages of their lives.... With respect [to] the condition in which children support their parents in their old age the economic assistance given was studied too. Finally, the preference regarding family size of those 60 years or older [is] given, as well as the view points of women on the need to control fertility and reduce family size. Three different types of cost are studied: the economic cost of supporting and caring for children, the emotional cost of their upbringing and the health cost of multiple pregnancies and births." (SUMMARY IN ENG)

Identification of Ser143 as the site of modification in the active site of histidine ammonia-lyase

Histidine ammonia-lyase (histidase) from Pseudomonas putida was irreversibly inactivated by L-cysteine at pH 10.5 in the presence of oxygen. Inactivation was accompanied by the formation of a new uv-absorbing species centered around 340 nm. L-[35S]cysteine labeling experiments revealed that 4 mol of L-cysteine was bound per mole of enzyme tetramer upon complete modification. However, the radiolabel was dissociated from the protein under denaturing conditions without loss of the 340-nm absorbance. Prior inactivation of histidase by cyanide, borohydride, or bisulfite precluded the formation of the 340-nm species in subsequent L-cysteine modification experiments. This suggests a common target site for modification of histidase by all of these reagents. Based on its strong absorbance at 340 nm an octapeptide was isolated from L-cysteine-inactivated histidase following trypsin and staphylococcal V8 protease digestion. Electrospray MS/MS revealed that this peptide (Gly138-SerValGlyAlaSerGlyAsp145) contained an unidentified modification of mass 184 Da located on Ser143. This peptide and the serine residue are conserved in all histidases and phenylalanine ammonia-lyases for which the amino acid sequence is available. Ser143 represents the binding site for an electrophilic cofactor required for histidase activity.

Purification and characterization of Pseudomonas putida histidine ammonia-lyase expressed in Escherichia coli

Histidine ammonia-lyase (HAL) from Pseudomonas putida PRS1 contains a catalytically important electrophilic center reported to be dehydroalanine. Little is known about the origin of this group or its linkage to the protein. To initiate structural studies on this enzyme, P. putida HAL was purified from an Escherichia coli high-expression clone in which the HAL gene (hutH) was under the control of the lambda PL promoter on a plasmid vector. In this clone from 6 to 10% of the soluble cell protein after heat induction was HAL and approximately 200 mg of 95% pure HAL could be obtained from 120 g wet weight of cells in a 40 to 60% yield. The overexpressed protein was identical to P. putida HAL in native molecular weight (220 kDa), subunit composition (four identical subunits of 53 kDa each), affinity for substrate (L-histidine Km of 5.3 mM at pH 9.0), and its sensitivity to inactivation by cyanide and bisulfite. The N-terminal amino acid sequence was in agreement with the DNA-predicted sequence, indicating proper translational initiation. These features make this enzyme an appropriate candidate for protein structure investigations regarding the nature of the electrophilic center and its association with the protein.

The order and orientation of a cluster of metalloproteinase genes, stromelysin 2, collagenase, and stromelysin, together with D11S385, on chromosome 11q22-q23

A cluster of metalloproteinase genes, stromelysin, fibroblast collagenase, and stromelysin 2 together with the anonymous DNA marker D11S385, was mapped using pulsed-field gel electrophoresis to a 135-kb region of chromosome 11q22-q23. The physical proximity of these markers was subsequently confirmed using two YAC clones, and their relative order was established as stromelysin 2-collagenase-stromelysin-D11S385. The pattern of marker representation in a panel of radiation-reduced chromosome 11 hybrids suggests that the metalloproteinase gene/D11S385 cluster is orientated with STMY2 closest to the centromere.