Diagnosis and clinical management of thrombotic thrombocytopenic purpura (TTP): a consensus statement from the TTP Catalan group

Thrombotic thrombocytopenic purpura (TTP) is a low prevalence disease characterized by severe deficiency of the enzyme ADAMTS13, leading to the development of thrombotic microangiopathy (TMA) and often resulting in severe organ disfunction. TTP is an extremely serious condition and, therefore, timely and appropriate treatment is critical to prevent life-threatening complications.Over the past 25 years, significant advances in the understanding of the pathophysiology of immune TTP have led to the development of readily available techniques for measuring ADAMTS13 levels, as well as new drugs that are particularly effective in the acute phase and in preventing relapses. These developments have improved the course of the disease.Given the complexity of the disease and its various clinical and laboratory manifestations, early diagnosis and treatment can be challenging.To address this challenge, a group of experienced professionals from the Catalan TTP group have developed this consensus statement to standardize terminology, diagnosis, treatment and follow up for immune TTP, based on currently available scientific evidence in the field. This guidance document aims to provide healthcare professionals with a comprehensive tool to make more accurate and timely diagnosis of TTP and improve patient outcomes.

The dynamics of arsenic and copper in solid and aqueous phases in reactive confluences receiving acid drainage: The role of turbidity and particle size

The fate of suspended solids in aqueous systems enriched with copper (Cu) and arsenic (As) is still poorly understood, especially in mildly acidic streams with natural turbidity. This study integrated field, laboratory, and modeling to determine how turbidity, particle size distribution, and the partition of Cu and As interact in two model river confluences in an Andean watershed (upper Elqui, North-Central Chile). The mildly acidic Toro River (4<pH<5; As_TOTAL>0.4 mgL^-1; Cu_TOTAL>8 mgL^-1) was diluted and neutralized at two consecutive confluences, resulting in dissolved As and Cu lower than 0.04 and 0.1 mgL^-1, respectively. On-site laser scattering measurements showed that the size of suspended sediments was dominated by ultrafine (d<6 μm) and fine (6<d<63 μm) size modes, while larger modes (d>200 μm) were not observed, contrasting with other reactive Andean confluences that work as natural coagulation-flocculation reactors. Laboratory mixing experiments with filtered endmembers followed closely the trends observed in the field measurements. SEM observations and thermodynamic calculations, suggested that As-rich amorphous Fe minerals dominated the fine suspended solid inflow (d<15 μm) from the Toro River, while XRD did not reveal significant amounts of crystalline forms of Fe, As, or Cu minerals. Despite fresh precipitates that further associated dissolved As and Cu, the particles from the Toro River grew only slightly after the confluences, thus limiting particle settling potential and a significant metal-(loid)s removal. Consequently, the seasonal variation in the size and chemical nature of suspended solids in acid drainage inflows control the distinct physical and chemical fates of As and Cu after neutralization, as well as hydrodynamic or hydraulic conditions likely also constrain sediment deposition. The combined monitoring of chemical parameters and particle size distributions is a simple and cost-effective method to obtain information about the behavior of metal(loid)s and sediments.

[Herpes zoster incidence in diabetic patients]

BACKGROUND

To assess the risk of herpes zoster in people with diabetes mellitus in comparison with the general population.

METHODS

Using computerized clinical reports form primary health care in Navarre, Spain, we analyzed the incidence of herpes zoster in people aged over 30 years in 2006 by diagnosis of diabetes, and adjusting for age and sex.

RESULTS

Among 26,793 diabetes patients 409 cases of herpes zoster were diagnosed (15 per 1000). Nineteen point three percent of cases occurred in diabetes patients. Diabetes presented an adjusted relative risk of 2.1 (95% CI 1.9-2.4), and increased to 3.7 (95% CI 2.0-6.8) in the 30-44 year age group. Of the total number of cases of herpes zoster in the population, 7.2% were attributable to diabetes.

CONCLUSION

Diabetes increases the risk of, and has a relevant role in, the incidence of herpes zoster.

Long-term evaluation and clinical outcomes of children with dental transplants in Temuco city, Chile

AIM

To assess the clinical and radiographic outcomes of 36 transplanted teeth and the possible factors affecting the results.

MATERIALS AND METHODS

In 26 children, 36 teeth transplants were performed. The main reason for transplantations was the loss of anterior teeth due to trauma; 80.5% of transplanted teeth were immature bicuspids. The transplants were clinically and radiolographycally monitored in respect of pulp vitality, root canal obliteration, periradicular changes and root formation. Fisher Exact Test and Kaplan-Meier analyses were performed to determine the association between the variables and estimation of survival rates, respectively.

RESULTS

Thirty (83.3%) of the transplantations were recorded as successful and six as unsuccessful (16.7%). The survival rate was 97.2% during average time of 47.5 months ± 27.8 SD. Only one tooth had been extracted and 5 had survived in not ideal conditions. The majority of immature transplanted teeth developed pulp canal obliteration.

CONCLUSION

Factors associated to successful outcome were immature root formation of donor tooth and short flexible splinting period. The main factor associated to failure was replacement resorption. The surgical technique did not present statistical significance in the clinical outcome. Tooth transplantation has shown high success and survival rates, and should be considered as a real option in growing patients.

Nucleotide sequence and infectious transcripts from a full-length cDNA clone of the carmovirus Melon necrotic spot virus

We have studied the biological and molecular characteristics of a MNSV isolate collected in Spain (MNSV-Malpha5) and generated a full-length cDNA clone from which infectious RNA transcripts can be produced. The host range of MNSV-Malpha5 appeared to be limited to cucurbits and did not differ from that of MNSV-Dutch [4, 21]. However, differences were observed in the type of symptoms that both isolates could induce. A full-length cDNA of MNSV-Malpha5 was directly amplified by reverse-transcription polymerase chain reaction (RT-PCR) using a 5'-end primer anchoring a T7 RNA promoter sequence and a 3'-end primer, and cloned. Uncapped RNAs transcribed from this cDNA clone were infectious and caused symptoms indistinguishable from those caused by viral RNA when mechanically inoculated onto melon, cucumber or watermelon plants. The complete genome sequence of MNSV-Malpha5 was deduced from the full length cDNA clone. It is 4271 nt long and, similarly to MNSV-Dutch, consists of 5' and 3' untranslated regions (UTRs) and five open reading frames (ORFs) coding for 29, 89, 42 and two small 7 kDa proteins. One notable difference between MNSV-Malpha5 and other sequenced MNSV isolates was found, as for MNSV-Malpha5 the first of the two small ORFs, which are contiguous in the genome, terminates with a genuine stop codon, whereas for MNSV-Dutch and other sequenced MNSV isolates it terminates with an amber codon. This suggested that the putative p14 readthrough protein that could be expressed from the MNSV-Dutch and other MNSV genomes could not be expressed from the MNSV-Malpha5 genome. Also, the nucleotide and amino acid sequences comparisons showed a distant relationship of MNSV-Malpha5 with other known MNSV isolates.

High Genetic Stability of the Begomovirus Tomato yellow leaf curl Sardinia virus in Southern Spain Over an 8-Year Period

ABSTRACT The evolution of the plant single-stranded DNA virus Tomato yellow leaf curl Sardinia virus (TYLCSV) (genus Begomovirus, family Geminiviridae) has been monitored for 8 years after its appearance in southern Spain. Variation within three genomic regions of 166 TYLCSV isolates collected from three locations was assessed by single-strand conformation polymorphism (SSCP) analysis. According to SSCP, the intergenic region (IR) was the most variable. Low genetic diversity was found within the population and geographical or temporal differences were not evident. Nucleotide sequences of specific genomic regions of haplotypes identified by SSCP indicated close relationships among them. Therefore, the Spanish TYLCSV population appears to represent a single, undifferentiated population. The analysis of IR sequences for a subsample of 76 randomly chosen isolates confirmed the limited genetic diversity revealed by the SSCP analysis. A tendency to a lineal increase in diversity over time was observed in Málaga and Almería subpopulations; however, no accumulation of mutations in single isolates was evident. Negative selection to variation seems to operate to conserve certain regions of the genome. Thus, the low genetic diversity found in the studied TYLCSV population might be the result of a founder effect with subsequent selection against less fit variants arising by mutation.

Spanish Melon necrotic spot virus Isolate Overcomes the Resistance Conferred by the Recessive nsv Gene of Melon

Melon necrotic spot virus (MNSV, genus Carmovirus, family Tombusviridae) is a worldwide natural pathogen that can cause significant economic losses in cucurbit crops (2). Use of commercial cultivars that carry the recessive nsv gene, the only resistance to MNSV described until now (1), is an effective means of controlling MNSV on melon crops. We report here the appearance of MNSV isolates able to overcome nsv resistance. Typical MNSV symptoms were observed in plants with an nsv/nsv genotype during a survey of melon in Almería (southeastern Spain) in 1999. The presence of MNSV in symptomatic plants was confirmed by standard double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) using commercial antisera (Loewe Biochemica GmbH, Sauerlach, Germany). MNSV was isolated from these samples by three serial single-lesion inoculation passages in melon (cv. Bola de Oro). The isolate obtained (MNSV-264) was characterized by sequencing a fragment of its RNA genome corresponding to most of the capsid protein (CP) gene. Briefly, total RNA extracts (TRI reagent, Sigma Chemical, St. Louis, MO) of MNSV-264-infected plants were used in a reverse transcription polymerase chain reaction (RT-PCR) in which the oligonucleotide for the reverse transcription was 5'-TTAGGCGAGGTAAGCAGTTTC-3' (MA34), and the oligonucleotides for the PCR were MA34 and 5'-ATGGCGATGGTTAAACGC-3' (MA32). MA32 and MA34 were designed based on an alignment of nucleotide sequences of CP genes of diverse MNSV isolates. A DNA product of approximately 1.1 kbp was obtained, purified, and sequenced (GenBank Accession No. AF488692). Sequence comparisons (GCG Software Package, Madison, WI) of MNSV-264 and MNSV-Dutch (2) showed a 93% nucleotide sequence identity and a 96% similarity of the deduced amino acid sequence. Therefore, both isolates appear to be closely related. MNSV-264 was inoculated on melon accessions known to be susceptible (cvs. Panal and Bola de Oro) or resistant (cvs. Primal F1, Planters Jumbo, and PI161375) to common MNSV strains. Inoculations with MNSV-Dutch were used as a control for this experiment. The results showed that MNSV-264 was able to infect plants of all genotypes, whereas MNSV-Dutch infected only plants of the susceptible genotypes. Therefore, MNSV-264 is an isolate able to overcome the resistance conferred by nsv. The genetic determinant of the MNSV-264 virulence on resistant genotypes is currently under investigation. From 55 MNSV isolates obtained from fields in southeastern Spain during the last 3 years, only one could overcome nsv, like MNSV-264. Therefore, resistance-breaking isolates are not frequent in the MNSV populations in Spain. It is plausible that the situation may change as a consequence of the widespread use of commercial melon cultivars with the nsv genotype. A search for new sources of genetic resistance to MNSV isolates like MNSV-264 is in progress in our laboratory. References: (1) D. L. Coudriet et al. J. Am. Soc. Hortic. Sci. 106:789, 1981. (2) C. J. Riviere et al. J. Gen. Virol. 70:3033, 1989.

Impact of induced aniseikonia on stereopsis with random-dot stereogram

In this work, we evaluate the impact of induced aniseikonia on stereopsis. For this, we determined the disparity range (maximum disparity), a parameter related to the size of the physical region that can be perceived stereoscopically. A significant decline in the disparity range was detected with aniseikonia induced by size lenses of 3% for five of the seven observers tested; 5% was necessary for the other two observers. The data indicate the influence of aniseikonia in stereopsis and the need to minimize such impact. These results may be useful in surgical processes such as the correction of pseudophakic patients and refractive surgery in which aniseikonia can be induced to alter the binocular function of the patient.

Binocular summation of chromatic changes as measured by visual reaction time

We determined visual reaction times to monocular and binocular changes in the luminance of isochromatic stimuli and to monocular and binocular changes in the color of isoluminant stimuli. Two isoluminant color changes were tested: chromatic variations along the red-green axis of Boynton's (1986) two-stage color vision model and chromatic variations along the yellow-blue axis of the same model. The results indicate a greater degree of binocular summation for luminance change than for color change. This result was largely independent of the motor component of reaction time.

[Topographical pachymetry and pachymetric topography in circumscribed posterior keratoconus]

CASE REPORT

A 29 year-old male patient presenting circumscribed posterior keratoconus in the left eye was studied. After ocular examination, corneal morphometry was studied by a computer-assisted topographic analysis and topographical ultrasonic pachymetry. Corneal thickness profile was represented by a colour-coded map from twenty-five measured points (pachymetric topography).

DISCUSSION

Slit lamp biomicroscopy shows a paracentral-localized area of moderate corneal thinning with a nasal-superior concavity on posterior corneal surface. Topographical pachometry and pachometric topography allow to make precise corneal thinning evaluation and offer useful diagnostic data for this rare corneal dystrophy.

Changes in stereoscopic depth perception caused by decentration of spectacle lenses

The effect that decentered spectacle (ophthalmic) lenses exert on depth perception has been studied, evaluating stereopsis through the disparity range (maximum horizontal disparity) for random-dot stereograms (RDS). The results show that variations in fusional convergence due to increments of decentration can diminish the stereopsis in observers, reducing the region within which stereoscopic correspondence can take place. Decreases in disparity ranges were found for vertical and horizontal prismatic effects, although the prismatic effect necessary for this was less in the vertical case. A decreased disparity range has also been confirmed with figural-stimuli stereograms and using prisms for generating the prismatic effects.

Synthesis and pharmacological evaluation of 2, 3-dihydro-3-oxo-4H-thieno[3,4-e][1,2,4]thiadiazine 1,1-dioxides as voltage-dependent calcium channel blockers

The synthesis of a novel series of 2,3-dihydro-3-oxo-4H-thieno[3, 4-e][1,2,4]thiadiazine 1,1-dioxides and their pharmacological evaluation as drugs with effects on the rat cardiovascular system are described. The compounds under study were synthesized via Curtius rearrangement of appropriate sulfamoylacylazides which, in turn, were prepared from known starting materials. In isolated rat portal vein, these thienothiadiazines, like verapamil and diazoxide, inhibited the spontaneous motility produced by KCl (20 mM). In addition, the new compounds, like verapamil and unlike diazoxide, also exhibited inhibitory effects in the same preparation when the cell membrane was depolarized by an increased extracellular KCl concentration (80 mM) and, consequently, the membrane potential approached a level close to the K(+) equilibrium potential. Further characterization of this inhibitory activity led to the identification of a selective inhibitory effect of the new compounds on KCl (80 mM)-induced 45Ca(2+) uptake in the same vascular tissue. When tested in vivo (anaesthetized normotensive rats), acute administration of verapamil, diazoxide and some of the most in vitro potent compounds in 45Ca(2+) uptake experiments produced a gradual, dose-dependent and sustained decrease in diastolic arterial blood pressure, devoid of cardiac effects. These results suggest that, like verapamil, the cardiovascular effects produced by the new thienothiadiazines seem to be due, at least in part, to a blockade of transmembrane voltage-dependent calcium channels present in vascular smooth muscle cells and not to an activation of ATP-sensitive K(+) channels. Compounds 5b, 5e and 5i have been selected for further studies as antihypertensive agents.

Synthesis and anti-HIV activity of 1,1,3-trioxo-2H,4H-thieno[3,4-e][1,2,4]thiadiazines (TTDs): a new family of HIV-1 specific non-nucleoside reverse transcriptase inhibitors

The anti-HIV activity of a novel series of 1,1,3-trioxo-2H,4H-thieno[3,4-e][1,2,4]thiadiazines (TTDs) has been described. The compounds were synthesized via Curtius rearrangement of appropriate sulfamoylcarboxy azides which, in turn, were prepared from known starting materials. Several 4-substituted-2-benzyl-derivatives were found to selectively inhibit human immunodeficiency virus type 1 [HIV-1 (IIIB)] replication in MT-4 and CEM cells. These TTDs were also effective against other strains of HIV-1 (RF, HE, MN, NDK), including those that are resistant to AZT, but not against HIV-2 (ROD) or simian immunodeficiency virus [SIV(MAC251)] at subtoxic concentrations. Some of the test compounds exhibited antiviral activity against L100I RT mutant virus, but significantly lost antiviral activity against K103N, V106A, E138K, Y181C and Y188H RT mutant viruses. Compounds 6d, 6f and 6g were inhibitory to HIV-1 RT at concentrations that rank between 16.4 and 59.8 microM (nevirapine: IC50 = 4.5 microM against HIV-1 RT). Inhibition of HIV-1 RT by compound 6g was purely non-competitive with respect to the natural substrate (dGTP), which is in agreement with the nature of inhibition shown by other NNRTIs such as nevirapine and delarvidine. A structure-activity relationship was established for the anti-HIV activity of these heterocyclic compounds. TTDs represent a new chemical class of non-nucleoside HIV-1 reverse transcriptase inhibitors (NNRTIs).

Displacement of Tomato Yellow Leaf Curl Virus (TYLCV)-Sr by TYLCV-Is in Tomato Epidemics in Spain

ABSTRACT A progressive displacement of tomato yellow leaf curl virus (TYLCV)-Sr by TYLCV-Is was observed in tomato epidemics in southern Spain based on incidence data of both virus species obtained during surveys conducted between 1996 and 1998. Ecological factors that might be involved in such a displacement, such as competition of TYLCV-Sr and TYLCV-Is in tomato, transmission by local biotypes (B and Q) of Bemisia tabaci, and presence in weeds and alternate crops, have been analyzed. No selective advantage is observed for TYLCV-Sr or TYLCV-Is in tomato plants either infected via Agrobacterium tumefaciens or via B. tabaci. However, TYLCV-Is is more efficiently vectored by local biotypes of B. tabaci; and common bean, a bridge crop between tomato crops, is a host for TYLCV-Is but not TYLCV-Sr. Therefore, common bean acts as a reservoir for TYLCV-Is. These two factors are probably responsible for the displacement of TYLCV-Sr by TYLCV-Is as the causative agent of epidemics in tomato in southern Spain.

Improvement of the print-capture polymerase chain reaction procedure for efficient amplification of DNA virus genomes from plants and insect vectors

A rapid and simple procedure is described to amplify efficiently geminivirus DNA genomes by improving the print-capture polymerase chain reaction (PCR) procedure reported recently for RNA viruses. This method, termed print-PCR (P-PCR), allows direct amplification of DNA from infected plant or whitefly tissues printed directly on Whatman 3MM paper, without the need of any grinding, incubation, or washing steps previous to the amplification reaction. P-PCR reduces sample manipulation and avoids previous extraction of nucleic acids, thereby diminishing the possibilities of cross-contamination between samples. P-PCR has been successfully applied to whiteflies and various plant species infected by two different tomato yellow leaf curl viruses, TYLCV-Sr and TYLCV-Is, and for the amplification of the full-length genome of TYLCV-Is from infected plants.

Novel 1,1,3-trioxo-2H,4H-thieno[3,4-e][1,2,4]thiadiazine derivatives as non-nucleoside reverse transcriptase inhibitors that inhibit human immunodeficiency virus type 1 replication

The 1,1,3-trioxo-2H,4H-thieno[3,4-e][1,2,4]thiadiazines (TTDs) represent a recently discovered chemical class of non-nucleoside reverse transcriptase inhibitors that selectively block human immunodeficiency virus type 1 replication. In a search for a better understanding of their mode of binding and with the aim of obtaining novel lead compounds, a second series of TTD derivatives was synthesized and evaluated for antiviral activity. The design of the new compounds was based on a variety of chemical modifications which were carried out in the original prototype 20a (QM 96521). Substitution of a halogen at the meta position of the N-2 benzyl group resulted in an improvement of the antiviral activity by 1 order of magnitude. Compounds bearing at the N-4 position a cyanomethyl, propargyl, or benzyl substituent were found to be the most potent of the series. Modifying the thieno[3,4-e] ring fused to the 1,2,4-thiadiazine moiety to other heterocyclic ring systems decreased the potency. The results obtained in this investigation have provided new indications for the design of even more effective TTDs.

Biochemical characterization of the Golgi-complex proteins of Tritrichomonas foetus

Using cell-fractionation techniques (differential and discontinuous gradient centrifugation), we obtained a highly enriched fraction containing the Golgi complex of Tritrichomonas foetus. This fraction was further subfractionated by sodium carbonate (150 mM) treatment at pH 11.5, leading to the isolation of the Golgi content and membrane subfractions. Both fractions were characterized by electron microscopy. The protein content of membrane and luminal subfractions was about 40% and 60% of the total Golgi protein, respectively. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis showed an enrichment of 15 protein bands in the Golgi fraction, with molecular masses varying between 15 and 116 kDa. Alkaline treatment released some proteins into the medium, but most of them were associated with the Golgi membrane.

First Report of Tomato Yellow Leaf Curl Virus-Is in Spain: Coexistence of Two Different Geminiviruses in the Same Epidemic Outbreak

Epidemics of tomato yellow leaf curl have occurred annually in greenhouse- and field-grown tomato (Lycopersicon esculentum Mill.) crops in southern Spain since 1992 (2). The nucleotide sequences of two tomato yellow leaf curl virus (TYLCV) isolates from this region, TYLCV-M (GenBank accession no. Z25751) and TYLCV-Alm (L27708), have been determined and these isolates are closely related to isolates reported from Italy (X61153 and Z28390), suggesting the existence of a geographical cluster of closely related TYLCV isolates in the Western Mediterranean Basin (2). In June 1997, new and unusually severe symptoms of stunting, yellowing, and curling of leaflet margins, with a marked reduction in leaf size, were observed in some plants of a greenhouse-grown tomato crop in Almeria (southeastern Spain). Tomato plants showing milder symptoms similar to those previously described for TYLCV infection in that region (2) were also present in the same greenhouse. Total nucleic acids extracts from plants exhibiting both types of symptoms were analyzed by dot blot hybridization with a probe prepared by random priming on a 1,674-bp SalI fragment of the pSP95 clone of TYLCV-M (3). A strong reaction was obtained with the samples that showed mild symptoms, whereas a weak reaction was observed with the severely affected plants. Specific pairs of primers were prepared to amplify the complete pre-coat (V1) (MA10: 5'-ATGTGGGATCCTTTATTAAATG-3'; MA11: 5'-TCAGGGCTTCTGTACATTC-3') and C2 (MA12: 5'-TAAAGACTCTTAAAAAATGACC-3'; MA13: 5'-AATGCAATCTTCGTCACC-3') genes based on TYLCV-M sequence. With polymerase chain reaction (PCR), the expected fragments were amplified from extracts of both types of plants. The PCR products were submitted to single-strand conformation polymorphism (SSCP) analysis. Clearly distinguishable SSCP patterns were obtained: one for the plants with mild symptoms, identical to that of known TYLCV-M infected plants, and another for the plants with more severe symptoms. Further analyses done on tomato samples collected from the same area showed that both SSCP patterns were present simultaneously in several severely affected plants. The nucleotide sequences of the V1 and C2 PCR products from two samples differing in their SSCP pattern were obtained by direct sequencing, and compared with available TYLCV sequences. The sequences corresponding to the sample with mild symptoms were 100% identical to those previously reported for TYLCV-M. In contrast, the sequences from the sample that showed severe symptoms (GenBank accesion no. AF022219 for V1, and AF022220 for C2) were only 80 and 76% identical to TYLCV-M V1 and C2 genes, respectively, but were 99% identical to the sequence reported for an isolate of TYLCV-Is from Israel (X15656). Epidemics in tomato caused by TYLCV-Is have been recently reported from Portugal (1). Our results demonstrate that the unusually severe symptoms observed are associated with an isolate of TYLCV-Is that coexists in the field with the milder TYLCV previously reported from this area. This is the first report of the occurence of TYLCV-Is in Spain. References: (1) D. Louro et al. Plant Dis. 80:1079, 1996. (2) E. Noris et al. Arch. Virol. 135:165, 1994.

Purification and biochemical characterization of the hydrogenosomes of the flagellate protozoan Tritrichomonas foetus

A highly purified hydrogenosomal fraction was obtained from Tritrichomonas foetus by differential and Percoll gradient centrifugations. Transmission electron microscopy and assay of the malic enzyme activity were used to evaluate the isolation method and the integrity of the organelle. The isolated hydrogenosomes showed the same morphology as observed in intact cells, including the presence of a peripheral vesicle with an electron-dense content. SDS-PAGE revealed the presence of several protein bands, with those of 120, 66, 60, 59, 48, 45, and 35 kDa as the major ones. The hydrogenosome membrane was solubilized with Triton X-100 leaving a fraction containing its matrix attached to the peripheral vesicle. Further treatment with proteinase K solubilized the matrix components, leaving a pure peripheral vesicle fraction. Enzymatic assay during all procedures suggested that malate dehydrogenase was localized in the hydrogenosomal membrane. SDS-PAGE showed that proteins of 66, 45 and 32 kDa were localized in the peripheral vesicle. Western blot analysis of all fractions using alkaline phosphatase-conjugated wheat germ agglutinin revealed the presence of glycoproteins, with a major one of 45 kDa, in the peripheral vesicle of the hydrogenosome.

Tritrichomonas foetus: isolation and characterization of the Golgi complex

An effective methodology to isolate and characterize the Golgi complex of Tritrichomonas foetus is described in this work. Using sucrose density gradient centrifugation, two highly enriched Golgi fractions (GF1 and GF2) were obtained. Enzymatic assays of GF1 and GF2 showed a strong enrichment in galactosyltransferase activity (20- and 7-fold, respectively), with minimal contamination with other organelles. The GF fraction was further subfractionated by alkaline treatment, which resulted in the production of Golgi content and membrane subfractions. Electron microscopic observations of intact cells or Golgi fractions fixed in solutions containing glutaraldehyde and tannic acid, as well as of deep-etched replicas of isolated fractions, revealed the presence of discrete bridges only between closely apposed cisternae.

Synthesis and antidepressant evaluation of new hetero[2,1]benzothiazepine derivatives

As a part of a research program directed to the discovery of novel antidepressant agents, a series of new hetero[2,1]benzothiazepine derivatives was synthesized. Some of these compounds antagonized the ptosis and motor depression induced by tetrabenazine and were also active in the Porsolt forced swimming test.

Synthesis and anti-inflammatory evaluation of new sulfamoylheterocarboxylic derivatives

A series of new sulfamoylthiophene and sulfamoylpyrazole carboxylic acid derivatives was synthesized. Some of these compounds show interesting analgesic properties and significant nonsteroidal anti-inflammatory activities in several models of inflammation.

Optimizing the constant-channel chromaticity and color gamut of CRT color displays by control of brightness and contrast levels

Before a CRT color display is calibrated, the levels of the brightness and contrast controls should be considered. These levels have different effects on the relationship between the chromaticity coordinates of the red-green-blue (RGB) channels and the voltage applied to the gun as well as on the color gamut. Using three different CRT color displays, we measured both these relationships as well as the color gamut for different combinations of brightness and contrast levels. With respect to the luminance range of the white point provided by each display, the results show that the assumption of constant-channel chromaticity of the RGB channels is more valid at medium- to low-brightness levels in combination with high-contrast levels. In addition, this assumption holds at high contrast and medium- to low-brightness levels, the color gamut being optimized at these combinations of levels, with regard to the size of the triangle of primaries-the maximum luminance of the display white point.

Isolation and biochemical characterization of the plasma membrane of Tritrichomonas foetus

A fraction containing plasma membrane-enriched vesicles has been prepared from Tritrichomonas foetus. Cells were ruptured using a Potter type homogenizer, under well controlled conditions, and membranes were isolated by differential centrifugation and in discontinuous sucrose gradient. This fraction was enriched 8 and 10-fold in the plasma membrane marker enzymes 5'-nucleotidase and (Na+ + K+)-dependent, ouabain-sensitive ATPase, respectively. Determination of Glucose-6-phosphatase and NADPH cytochrome c reductase activities in this fraction, indicates a minimal contamination with endoplasmic reticulum membranes. Analysis by Sodium Dodecyl Sulfate-Polyacrylamide (SDS-PAGE) gradient gel showed that the plasma membrane fraction contains several proteins with major bands corresponding to apparent molecular weights of 48, 45, 39, 37, 32, 30, 27, 23, 20, 19, 17, and 15 kDa.

[Lipoprotein(a) concentrations in type I diabetes mellitus]

OBJECTIVES

To determine the distribution of lipoprotein(a) levels and prevalence of hyperLp(a) in diabetes mellitus type I (IDDM). To analyze the effect of glycemic control and microalbuminuria on Lp(a) levels.

METHODS

Cross-sectional study of 263 subjects with IDDM with a mean age of 19.2 +/- 11.6 years and an evolutive course of 6.3 +/- 6.5 years. Apart from Lp(a), measurements were obtained from serum levels of lipids, apolipoproteins AI and B, fructosamine, glycosilated hemoglobin (HbA1c), and albuminuria in all patients.

RESULTS

Mean serum concentrations of Lp(a) were 16.5 +/- 18.1 mg/dl and 18.5% of patients had Lp(a) levels > 30 mg/dl [hyperLp(a)]. With a multivariate regression analysis, the only variable correlated with Lp(a) levels was cholesterol LDL (p < 0.001). Patients with hyperLp(a) did not differ from the other patients in any of the other variables analyzed, and patients with HbA1c higher and lower than 8% had similar mean serum Lp(a) concentrations (14.0 +/- 16 vs. 17.9 +/- 20). Lp(a) concentration was also similar among patients with albuminuria higher and lower than 20 micrograms/min (16.6 +/- 20 vs. 17.7 +/- 16).

CONCLUSIONS

Control of glycemia and microalbuminuria have no effect on Lp(a) concentrations in diabetes mellitus type I. HyperLp(a) is not indicative of a poor glycemic control.

Influence of the luminance signal and red-green and yellow-blue opponent chromatic signals in figural-stimuli stereograms

The influence of color signals on stereopsis has been studied using figural-stimuli stereograms with variations introduced according to the opponent chromatic channels (red-green and yellow-blue), derived from Boynton's color-vision model. We used wallpaper stereograms, which enable the rank-order disparity ranges of the chromatic and luminance signals to be compared with the rank-order disparity range of proximity, a particular spatial configuration of the stereogram in which there are no variations in chromaticity and/or luminance. The results indicate that both chromatic signals contribute to stereopsis as does the luminance signal, contradicting the model of Hubel and Livingstone. The results also show there are no clear dependencies upon the kind of signal processed, as luminance and chromatic variations are processed with the same efficiency.

Differences in antidiabetic drug utilisation between three different health systems in the same national region

The consumption of antidiabetic drugs in a Spanish region (Extremadura) in the period 1986-1987 has been investigated by the "defined daily dose" (DDD) method. The study was done in three health care systems in the region: civil servants ("Mutualidad de Funcionarios Civiles del Estado: MUFACE") armed forces group ("Instituto Social de las Fuerzas Armadas: ISFAS") and the national system ("Instituto Nacional de la Salud: INSALUD"). The total consumption of antidiabetic drugs varied three-fold, ranging from 5,73 DDD per 1000 inhabitants per day (3,71 DDD per 1000 inhabitants per day for oral antidiabetic drugs and 2,02 DDD per 1000 inhabitants per day for insulin) in the civil servant group to 15,82 DDD per 1000 inhabitants per day (12 DDD per 1000 inhabitants per day for oral antidiabetic drugs and 3,82 DDD per 1000 inhabitants per day for insulins) in the armed forces. The differences were more pronounced for oral antidiabetics than for insulins. The utilization of insulin among the civil servants was about half of that by the two other groups. Of oral antidiabetics, sulphonylureas were the most frequently used by the three groups, and within them glibenclamide accounted for more than half of the DDDs, while biguanides were scarcely used in any group. The differences are difficult to assess, since they could be due to several factors, such as age-differences in the population studied, different prescribing habits, and differences in sociocultural level. The results justify further comparative studies of drug utilization in different health systems within the same region.