Characteristics of adults with Down syndrome hospitalised in Spanish internal medicine departments during 2005-2014

INTRODUCTION AND OBJECTIVES

The clinical problems of adults with Down syndrome seem to differ from those of the general population. To better understand these differences, we list the demographic and clinical characteristics of adults with Down syndrome admitted to Spanish internal medicine departments during 2005-2014.

PATIENTS AND METHODS

We conducted an observational retrospective study using data collected from the minimum basic data set on hospitalisation episodes of adults with Down syndrome in the internal medicine departments of Spain's National Health System from 2005 to 2014. We analysed the patients' epidemiological, clinical and societal data.

RESULTS

A total of 7548 hospitalisation episodes from 3786 patients were recorded. Some 56.6% of the patients were male with a mean age (±SD) of 47±13 years, and 715 of the patients died (18.9%). The age-adjusted mortality was 26.6%, and the mean stay was 9.6±12 days. The hospitalisation was for respiratory disease in 3684 episodes (48.8%) and for cardiac origin in 760 (10%). The most common comorbidities were hypothyroidism (27.1%, 2043 episodes), epilepsy (24.1%, 1819 episodes) and dementia (15.4%, 1162 episodes).

CONCLUSIONS

The hospitalisation of adults with Down syndrome in internal medicine departments has increased in the past decade. Although the reasons for hospitalisation, mean stay and cost per episode for this population are similar to those of the general population treated by internal medicine departments, the age-adjusted hospital mortality was significantly greater.

Ovarian stimulation does not influence the uterine immune environment in healthy infertile women

RESEARCH QUESTION

There is some controversy regarding the impact of ovarian stimulation on immune cells in women undergoing IVF. The study's aim was to determine whether ovarian stimulation affected immune uterine cells in healthy women undergoing IVF.

DESIGN

This prospective cohort study included 28 patients undergoing IVF and 47 healthy oocyte donors. Endometrial biopsies were taken in a natural cycle and after ovarian stimulation. All participants had a normal karyotype, pelvic ultrasound and cervical cytology results and thyroid-stimulating hormone concentration, as well as normal glucose and insulin concentrations and inherited and acquired thrombophilia test results. Screening tests including human papillomavirus were normal. Immune cells were analysed using three techniques: fluorescence-activated cell sorting, immunohistochemistry and gene expression. A human leukocyte antigen (HLA)-C tetramer was used as an 'artificial embryo'. The expression of genes including those for tumour necrosis factor (TNF)-α and interleukin-10 (IL-10) was analysed.

RESULTS

A comparison was made of the percentage and gene expression of CD56^brightCD16^- uterine natural killer (uNK), CD56^dimCD16⁺ natural killer cells, CD56^-CD16⁺ natural killer cells and TregCD25⁺CD4⁺FoxP3⁺ cells, uNK binding to the HLA-C tetramer, and TNF-α and IL-10 expression. No between- or within-group differences were observed in natural versus ovarian stimulation cycles.

CONCLUSIONS

Ovarian stimulation does not affect the uterine immune cell population or HLA-C binding in healthy women undergoing ovarian stimulation. Further studies are underway to find out if different responses might be seen in women with previous autoimmune disorders.

Role of the 807 C/T Polymorphism of the α2 Gene in Platelet GP Ia Collagen Receptor Expression and Function

The variability of the platelet GP Ia/IIa density has been associated with the 807 C/T polymorphism (Phe 224) of the GP Ia gene in American Caucasian population. We have investigated the genotype and allelic frequencies of this polymorphism in Spanish Caucasians. The T allele was found in 35% of the 284 blood donors analyzed. We confirmed in 159 healthy subjects a significant association between the 807 C/T polymorphism and the platelet GP Ia density. The T allele correlated with high number of GP Ia molecules on platelet surface. In addition, we observed a similar association of this polymorphism with the expression of this protein in other blood cell types. The platelet responsiveness to collagen was determined by “in vitro” analysis of the platelet activation and aggregation response. We found no significant differences in these functional platelet parameters according to the 807 C/T genotype. Finally, results from 3 case/control studies involving 302 consecutive patients (101 with coronary heart disease, 104 with cerebrovascular disease and 97 with deep venous thrombosis) determined that the 807 C/T polymorphism of the GP Ia gene does not represent a risk factor for arterial or venous thrombosis.

Oral anticoagulation in primary care

Oral anticoagulant therapy is currently widespread in the population and primary care plays an important role in its control in Spain. Younger populations, such as those in prisons, often require this treatment for reasons other than atrial fibrillation, often in relation to valvular or congenital or acquired hypercoagulability situations. The possibility of obtaining the INR by portable coagulometers has allowed primary care physicians to tackle the indication of this therapy and the control of these patients in coordination with haematology services. The emergence of new therapeutic alternatives (Dabigatran, Rivaroxaban, Apixaban and Edoxaban, the so called "ACOD") has permitted the expansion of options for oral anticoagulation in some cases, since they do not require systematic monitoring of their effect and interact with far fewer drugs than their predecessors, although there are still restrictions by the health authorities on their widespread use. This article reviews the different indications of oral anticoagulant therapy according to the new recommendations as well as the clinical scenarios in which it should be used.

Spatial distribution and cluster analysis of a leishmaniasis outbreak in the south-western Madrid region, Spain, September 2009 to April 2013

Binary file ES_Abstracts_Final_ECDC.txt matches

Sonographic predictors of surgery in fetal coarctation of the aorta

OBJECTIVES

Isolated fetal coarctation of the aorta (CoA) has high false-positive diagnostic rates by cardiologists in tertiary centers. Isthmal diameter Z-scores (I), ratio of isthmus to duct diameters (I:D), and visualization of CoA shelf (Shelf) and isthmal flow disturbance (Flow) distinguish hypoplastic from normal aortic arches in retrospective studies, but their ability to predict a need for perinatal surgery is unknown. The aim of this study was to determine whether these four sonographic features could differentiate prenatally cases which would require neonatal surgery in a prospective cohort diagnosed with CoA by a cardiologist.

METHODS

From 83 referrals with cardiac disproportion (January 2006 to August 2010), we identified 37 consecutive fetuses diagnosed with CoA. Measurements of I and I:D were made and the presence of Shelf or Flow recorded. Sensitivity, specificity and areas under receiver-operating characteristics curves, using previously reported limits of I < - 2 and I:D < 0.74, as well as Shelf and Flow were compared at first and final scan. Associations between surgery and predictors were compared using multivariable logistic regression and changes in measurements using ANCOVA.

RESULTS

Among the 37 fetuses, 30 (81.1%) required surgery and two with an initial diagnosis of CoA were revised to normal following isthmal growth, giving an 86% diagnostic accuracy at term. The median age at first scan was 22.4 (range. 16.6-7.0) weeks and the median number of scans per fetus was three (range, one to five). I < - 2 at final scan was the most powerful predictor (odds ratio, 3.6 (95% CI, 0.47-27.3)). Shelf was identified in 66% and Flow in 50% of fetuses with CoA.

CONCLUSION

Incorporation of these four sonographic parameters in the assessment of fetuses with suspected CoA at a tertiary center resulted in better diagnostic precision regarding which cases would require neonatal surgery than has been reported previously.

Loss of poly(ADP-ribose) polymerase-2 leads to rapid development of spontaneous T-cell lymphomas in p53-deficient mice

Poly(ADP-ribose) polymerase-2 (Parp-2) belongs to a family of enzymes that catalyse poly(ADP-ribosyl)ation of proteins. Parp-2 deficiency in mice (Parp-2(-/-)) results in reduced thymic cellularity associated with increased apoptosis in thymocytes, defining Parp-2 as an important mediator of T-cell survival during thymopoiesis. To determine whether there is a link between Parp-2 and the p53 DNA-damage-dependent apoptotic response, we have generated Parp-2/p53-double-null mutant mice. We found that p53(-/-) backgrounds completely restored the survival and development of Parp-2(-/-) thymocytes. However, Parp-2-deficient thymocytes accumulated high levels of DNA double-strand breaks (DSB), independently of the p53 status, in line with a function of Parp-2 as a caretaker promoting genomic stability during thymocytes development. Although Parp-2(-/-) mice do not have spontaneous tumours, Parp-2 deficiency accelerated spontaneous tumour development in p53-null mice, mainly T-cell lymphomas. These data suggest a synergistic interaction between Parp-2 and p53 in tumour suppression through the role of Parp-2 in DNA-damage response and genome integrity surveillance, and point to the potential importance of examining human tumours for the status of both genes.

Simultaneous immunoaffinity column cleanup and HPLC analysis of aflatoxins and ochratoxin A in Spanish bee pollen

Bee pollen is a major substrate for mycotoxins growth when no prompt and adequate drying is performed by the beekeeper after collection by bees. Regulatory limits for aflatoxins and ochratoxin A are currently in force in the European Union for a rising list of foodstuffs, but not for this. An immunoaffinity column cleanup process has been applied prior to the analysis of aflatoxins B(1), B(2), G(1), and G(2) and ochratoxin A (OTA). Optimization of the HPLC conditions has involved both a gradient elution and a wavelength program for the separation and fluorimetric quantitation of all five mycotoxins at their maximum excitation and emission values of wavelength in a single run. The higher limit of detection (mug/kg) was 0.49 for OTA and 0.20 for aflatoxin B(1). Repeatability (RSDr) at the lower limit tested ranged from 9.85% for OTA to 6.23% for aflatoxin G(2), and recoveries also at the lower spiked level were 73% for OTA and 81% for aflatoxin B(1). None of the 20 samples assayed showed quantifiable values for the five mycotoxins.

Domain architecture of a high mobility group A-type bacterial transcriptional factor

Myxococcus xanthus transcriptional factor CarD participates in carotenogenesis and fruiting body formation. It is the only reported prokaryotic protein having adjacent "AT-hook" DNA-binding and acidic regions characteristic of eukaryotic high mobility group A (HMGA) proteins. The latter are small, unstructured, nonhistone nuclear proteins that function as architectural factors to remodel DNA and chromatin structure and modulate various DNA binding activities. We find CarD to be predominantly dimeric with two stable domains: (a) an N-terminal domain of defined secondary and tertiary structure which is absent in eukaryotic HMGA proteins; (b) a C-terminal domain formed by the acidic and AT-hook segments and lacking defined structure. CarD, like HMGA proteins, binds specifically to the minor-groove of AT-rich DNA present in two appropriately spaced tracts. As in HMGA proteins, casein kinase II can phosphorylate the CarD acidic region, and this dramatically decreases the DNA binding affinity of CarD. The acidic region, in addition to modulating DNA binding, confers structural stability to CarD. We discuss how the structural and functional plasticity arising from domain organization in CarD could be linked to its role as a general transcriptional factor in M. xanthus.

Human anti-porcine gammadelta T-cell xenoreactivity is inhibited by human FasL expression on porcine endothelial cells

BACKGROUND

The role of gammadelta T cells during an immune response is still elusive and has been proposed to play a first line of defense along with other cells of the innate immune system, such as macrophages and natural killer cells, before alphabeta T-cell activation occurs. Innate cellular immune response plays a major role in xenograft rejection. We investigated the response of human gammadelta T cells to unmodified and human FasL (hFasL)-expressing xenogenic porcine endothelial cells.

METHODS

A 51Cr release assay was used to study the xenoreactivity of human gammadelta T-cell clones against porcine endothelial cells. Stable transfectants of porcine endothelial cells expressing hFasL were established and analyzed for their effectiveness in controlling this response.

RESULTS

Of the gammadelta T-cell clones tested, 38.9% were cytotoxic for porcine endothelial target cells. This cytotoxic response of human gammadelta T-cell clones was significantly inhibited by a monoclonal antibody against human CD3. Incubation of gammadelta T-cell clones with concanamycin A, an inhibitor of the perforin/granzyme B pathway, caused inhibition of lysis of porcine endothelial cells. Inhibition was not observed upon incubation with either anti-FasL or anti-tumor necrosis factor-alpha monoclonal antibodies. Expression of hFasL on porcine endothelial cells significantly reduced lysis by human gammadelta T cells.

CONCLUSION

These results imply that human gammadelta T cells may represent an important obstacle to xenotransplantation. Specific strategies targeted at this subset of T cells could be important in controlling innate cellular response to xenografts and facilitate graft survival.

Role of the 807 C/T polymorphism of the alpha2 gene in platelet GP Ia collagen receptor expression and function--effect in thromboembolic diseases

The variability of the platelet GP Ia/IIa density has been associated with the 807 C/T polymorphism (Phe 224) of the GP Ia gene in American Caucasian population. We have investigated the genotype and allelic frequencies of this polymorphism in Spanish Caucasians. The T allele was found in 35% of the 284 blood donors analyzed. We confirmed in 159 healthy subjects a significant association between the 807 C/T polymorphism and the platelet GP Ia density. The T allele correlated with high number of GP Ia molecules on platelet surface. In addition, we observed a similar association of this polymorphism with the expression of this protein in other blood cell types. The platelet responsiveness to collagen was determined by "in vitro" analysis of the platelet activation and aggregation response. We found no significant differences in these functional platelet parameters according to the 807 C/T genotype. Finally, results from 3 case/control studies involving 302 consecutive patients (101 with coronary heart disease, 104 with cerebrovascular disease and 97 with deep venous thrombosis) determined that the 807 C/T polymorphism of the GP Ia gene does not represent a risk factor for arterial or venous thrombosis.

Triggering of effector functions on a CD8+ T cell clone upon the aggregation of an activatory CD94/kp39 heterodimer

Some T lymphocytes express the CD94 Ag, which is known to form heterodimers with members of the NKG2 family. We have studied the expression pattern and function of CD94 heterodimers in different alphabeta or gammadelta T cell clones. Most of the CD94+NKG2A- T cells have a low to intermediate expression of CD94 Ag. The cross-linking of the CD94/NKG2 heterodimer in one of these CD8 alphabeta CD94+NKG2A- T cell clones (K14B06) was able to: 1) increase the intracellular concentration of Ca2+, 2) induce the up-regulation of CD25 Ag expression and the secretion of IFN-gamma, and 3) trigger redirected cytotoxicity in a TCR-independent manner. This activatory property was not shared by any other costimulatory molecule expressed by the K14B06 T cell clone, including CD8, CD28, CD45, CD69, or CD2 Ags. The immunoprecipitation of CD94 heterodimer showed a 39-kDa band with a similar m.w. to the activatory heterodimer found on some NK clones. A novel form of the NKG2 family (NKG2H) was identified in K14B06. NKG2H protein represents an alternative spliced form of the NKG2E gene, displaying a charged residue in the transmembrane portion and a cytoplasmic tail that lacks immunoreceptor tyrosine-based inhibitory motifs. The expression of NKG2H in the cell membrane through its association to CD94 and DAP-12 molecules supports that it could form part of the activatory CD94/Kp39 heterodimer present on K14B06 cells.

[Brachmann-de-Lange syndrome in our population: clinical and epidemiological characteristics]

INTRODUCTION

We present the study of the clinical and epidemiological characteristics of Brachmann-de Lange syndrome in our population.

PATIENTS AND METHODS

In this study we present the analysis of 13 cases of Brachmann-de Lange syndrome identified among 24,696 infants with congenital defects registered by the Spanish Collaborative Study of Congenital Malformations (ECEMC) between April 1976 and June 1996.

RESULTS

The minimum estimation of the prevalence in our population is 0.97 per 100,000 live births. We have epidemiologically confirmed the presence of intrauterine growth retardation and have observed that parental ages tend to be relatively young. We have observed a wide range of clinical expression of this syndrome. One hundred percent of our cases have limb reduction defects, followed in frequency by craniofacial alterations (84.62%), abnormal hair distribution (76.92%) and genital defects (69.23%). Upper limbs are predominantly affected and one case of diaphragmatic hernia is worth mentioning. We underline the importance of the differential diagnosis with Fryns'syndrome.

CONCLUSIONS

The cases studied correspond to the most severe form of the syndrome, reason for which the prevalence is a minimal estimate. However, the mild forms of the syndrome are more frequent and it is important to consider that the face, especially the form of the eyebrow, could be a good guide for the diagnosis of mild forms of the syndrome.

Description of the characteristics of cases with noncontiguous neural tube defects identified in a series of consecutive births

Van Allen et al. [(1973) Am. J. Med. Genet. 47:723-743] provided evidence for multisite closure of the neural tube in humans. Reynolds et al. [(1995) Proceedings of the Greewood Genetic Center 14:70-71] and Seller [(1995) J. Med. Genet. 32:205-207] described 13 and seven cases of noncontiguous neural tube defects (NTDs) respectively and concluded that the presence of noncontiguous NTDs cannot be explained on the basis of the model of a single initiation site with bidirectional closure. Here we present a series of 14 consecutive infants with noncontiguous NTDs, describing their characteristics. These show that noncontiguous NTDs are clinically heterogeneous, may have differences in sex ratio, and could have causal heterogeneity. The different combinations of closure failure defects have shown proportions in our population that are different from those in the populations studied by Reynolds et al. and Seller.

[Children with limb reductions in a population of 25,193 malformed newborns: the recognized causes. ECEMC. The Spanish Collaborative Study of Congenital Malformations]

OBJECTIVE

The purposes of this study were to analyze the causes of limb reduction deficiencies based on a clinical-epidemiological approach and to study the causes by clinical presentation.

PATIENTS AND METHODS

We have used the data from the Spanish Collaborative Study of Congenital Malformations (ECEMC) during the period from 1976 to 1996, which corresponded to more than 1,300,000 births. Among these, we identified 851 liver-born and 40 stillborn infants with limb reduction defects.

RESULTS

We could identify the cause in 177 (19.87%) of the 891 cases with limb reduction defects. In the analysis by clinical presentation, in 52.19% of the cases the limb deficiencies were the only defect present in the children (isolated), 30.75% presented multiple congenital anomaly patterns, and 17.06% were syndromes. The most frequent etiology was the genetic one.

CONCLUSIONS

First, most of infants with limb deficiencies have unknown cause and these defects are most frequently isolated malformations. On the other hand, the results of this analysis permitted the following considerations in relation to the guidance for the diagnosis of infants with limb reduction defects. If the child presents with multiple congenital anomalies (multiply malformed infant) a chromosomal analysis should be performed and it should be determined if the infant was prenatally exposed to a teratogenic agent. If these two aspects are normal, we should clinically analyze if the infant could have a known syndrome. In addition, since in our data 10.32% of isolated cases were due to autosomal dominant genes, a detailed clinical analysis of close relatives should be done to determine if some of them present mild limb deficiencies in order to provide an adequate information to the family.

Amelia: analysis of its epidemiological and clinical characteristics

Eighteen cases of amelia in the Spanish Collaborative Study of Congenital Malformations (ECEMC) were analyzed epidemiologically. Prevalence at birth was 0.15 per 10,000 newborn infants, which is not different from that reported by other authors. Affected females outnumbered males. When compared with the control group, a lower birth weight, shorter gestation, lower placental weight, greater frequency of single umbilical artery, noncephalic presentation at birth, and more frequent maternal vaginal bleeding were observed in amelia cases. There were no significant variations of parental age. None of these patients was exposed to known teratogens, apart from 1 born to a diabetic mother; 3 patients had a genetic condition. Comparison of these variables with other studies is difficult because there is only one study that specifically analyzed amelia. Our data together with previous observations suggest that the genetic basis of amelia might be more important than has been considered previously.

Transforming growth factor-beta1 inhibits basal melanogenesis in B16/F10 mouse melanoma cells by increasing the rate of degradation of tyrosinase and tyrosinase-related protein-1

Current evidence suggests that melanogenesis is controlled by epidermal paracrine modulators. We have analyzed the effects of transforming growth factor-beta1 (TGF-beta1) on the basal melanogenic activities of B16/F10 mouse melanoma cells. TGF-beta1 treatment (48 h) elicited a concentration-dependent decrease in basal tyrosine hydroxylase and 3,4-dihydroxyphenylalanine (Dopa) oxidase activities, to less than 30% of the control values but had no effect on dopachrome tautomerase activity (TRP-2). The inhibition affected to similar extents the Dopa oxidase activity associated to tyrosinase-related protein-1 (TRP-1) and tyrosinase. This inhibition was noticeable between 1 and 3 h after the addition of the cytokine, and maximal after 6 h of treatment. The decrease in the enzymatic activity was paralleled by a decrease in the abundance of the TRP-1 and tyrosinase proteins. TGF-beta1 mediated this effect by increasing the rate of degradation of tyrosinase and TRP-1. Conversely, after 48 h of treatment, the expression of the tyrosinase gene decreased only slightly, while TRP-1 and TRP-2 gene expression was not affected. An increased rate of proteolytic degradation of TRP-1 and tyrosinase seems the main mechanism accounting for the inhibitory effect of TGF-beta1 on the melanogenic activity of B16/F10 cells.

Specific regulation of VLA-4 and alpha 4 beta 7 integrin expression on human activated T lymphocytes

Modulation of VLA integrins was studied in several human T cell clones upon specific and nonspecific cellular activation. Human activated T lymphocytes down-regulated both alpha 4 beta 1 and alpha 4 beta 7 integrins upon specific recognition of alloantigens (cytotoxic T cells) or in the presence of Staphylococcus enterotoxin B (superantigen recognizing noncytotoxic T cells). In contrast, the expression of other membrane integrins, such as VLA-1 and VLA-5 integrins, was not modified. Down-regulation of alpha 4 beta 1 and alpha 4 beta 7 integrins was observed as early as 3 h after stimulation, lasted later than 72 h and was partially inhibited by cytochalasin D. Interestingly, neither target cells nor NK cells modulated CD49d expression after interaction with T cells of K562, respectively, suggesting that CD49d expression was linked to specific T cell activation. The down-regulation of the CD49d chain in T cell clones stimulated with immobilized anti-CD3 mAbs confirmed the role of TCR-mediated activation in CD49d regulation. However, the CD3-independent cellular aggregation induced by soluble anti-CD43 mAb was also able to strongly down-regulate alpha 4 beta 1 and alpha 4 beta 7. The present work shows the first evidence that CD49d subunit-bearing integrin expression is distinctly regulated from other integrins after Ag or superantigen recognition by human activated T cells. CD49d modulation may be relevant for the traffic and tissue localization of locally activated T cells during immune responses.

Specific regulation of VLA-4 and alpha 4 beta 7 integrin expression on human activated T lymphocytes

Modulation of VLA integrins was studied in several human T cell clones upon specific and nonspecific cellular activation. Human activated T lymphocytes down-regulated both alpha 4 beta 1 and alpha 4 beta 7 integrins upon specific recognition of alloantigens (cytotoxic T cells) or in the presence of Staphylococcus enterotoxin B (superantigen recognizing noncytotoxic T cells). In contrast, the expression of other membrane integrins, such as VLA-1 and VLA-5 integrins, was not modified. Down-regulation of alpha 4 beta 1 and alpha 4 beta 7 integrins was observed as early as 3 h after stimulation, lasted later than 72 h and was partially inhibited by cytochalasin D. Interestingly, neither target cells nor NK cells modulated CD49d expression after interaction with T cells of K562, respectively, suggesting that CD49d expression was linked to specific T cell activation. The down-regulation of the CD49d chain in T cell clones stimulated with immobilized anti-CD3 mAbs confirmed the role of TCR-mediated activation in CD49d regulation. However, the CD3-independent cellular aggregation induced by soluble anti-CD43 mAb was also able to strongly down-regulate alpha 4 beta 1 and alpha 4 beta 7. The present work shows the first evidence that CD49d subunit-bearing integrin expression is distinctly regulated from other integrins after Ag or superantigen recognition by human activated T cells. CD49d modulation may be relevant for the traffic and tissue localization of locally activated T cells during immune responses.

Conjugation between cloned human NK cells (H7.8) and K562/MOLT4 tumor cell systems: saturability, binding parameters, and population distribution of conjugates

Effector-target conjugation between cloned NK(H7.8)-K562 and NK(H7.8)-MOLT4 tumor cells has been studied from binding isotherms. Nonlinear and linear regression methods were used to calculate the maximum effector and target conjugate frequencies as well as the dissociation constant of the conjugates formed. The results obtained show there is an enhancement of the effector-target saturability and effector-target affinity in comparison with the values previously observed for polyclonal NK effector cells. Population distributions revealed that different types of conjugates were formed as the effector-to-target ratio was changed in the NK(H7.8)-K562 and NK(H7.8)-MOLT4 tumor cells. In both cases conjugates where one effector cell was bound to several target cells and conjugates with one target cell bound to several effector cells were found. At all values of R the prevailing conjugates were those with one effector cell bound to one target cell.

[Epidemiological characterization of Haemophilus influenzae using molecular markers]

BACKGROUND

Haemophilus influenzae is the etiological agent of acute- (meningitis, sepsis, pneumonia, epiglottis) and chronic infections (cystic fibrosis, chronic obstructive pulmonary infections). Several clinical (chronic infections) and epidemiological situations (community and hospital outbreaks) require the use of epidemiological typing methods.

OBJECTIVE

We evaluated four typing methods to characterize clinical isolates of H. influenzae.

METHODS

Forty-five clinical strains of H. influenzae were studied by biotype, serotype and antibiotype techniques, and the following methods: isoenzyme electrophoresis mobility, outer membrane proteins (OMP), ribotyping and pulsed field gel electrophoresis (PFGE).

RESULTS

Type b strains had one pattern with Isoenzyme, OMP and ribotyping techniques. Only PFGE enabled us to differentiate between several type b patterns, although all of them were close related. All methods showed a great variety of patterns with the non-typable H. influenzae although clinical- or epidemiological-related strains had identical patterns.

CONCLUSIONS

Results obtained with all four markers studied showed good agreement. Type b strains, in contrast to non-typable strains, had a strong clonal structure with all the assayed techniques; only PFGE showed differences. In terms of technical and financial cost, as well as reproducibility and discriminative power, we suggest as a markers for H. influenzae OMP and PFGE.

Inter-centre comparison of pulsed-field gel electrophoresis for the typing of methicillin-resistant Staphylococcus aureus

The results of pulsed-field gel electrophoresis (PFGE) of chromosomal DNA of the same 12 methicillin-resistant S. aureus (MRSA) strains of diverse geographical origin, performed in three different laboratories were compared; one laboratory used field-inversion gel electrophoresis (FIGE), one used contour clamped homogenous electrophoresis (CHEF) and one used both (all manufactured by BioRad Laboratories Inc., Hercules, CA, USA). No single method produced the maximum number of chromosomal fragments from all isolates. In only four instances were the same number of fragments identified by any two techniques. Although there were similar trends in strain identification the results showed many discrepancies even with a three-band difference rule to discriminate between strains. Plasmids in seven of the isolates produced a fragment, but this did not affect discrimination of the study isolates. There is a great need to standardise methodology and produce a standard set of strains to assist in this process.

Severe congenital limb deficiencies, vertebral hypersegmentation, absent thymus and mirror polydactyly: a defect expression of a developmental control gene?

We describe two unrelated patients with a complex malformation pattern that may be a candidate for a developmental gene disorder. These two patients had severe, symmetrical upper and lower limb deficiencies, vertebral hypersegmentation, and duodenal atresia. Patient 1 also had mirror-image polydactyly of his feet; patient 2 was athymic. The concurrence in two unrelated patients of additional vertebrae with severe anomalies in limb development, including a symmetrical deficiency of the four limbs and either mirror-image duplication of some toes (only in patient 1) or absence of the thymus (only in patient 2), represents an early alteration in body-plan organization. Since limb development, thymus development and segmentation are possibly under the control of homeobox genes in the human embryo, it seems reasonable that the malformations observed in these two patients resulted from a defect of a gene controlling developmental pattern formation, possibly a homeobox gene or a paired-box gene. Severe limb deficiencies have been reported in other well-known genetic entities, such as Roberts syndrome, Baller-Gerold syndrome, X-linked amelia, and DK-phocomelia syndrome. However, since the specific pattern of anomalies observed in these patients makes the diagnosis of some of the abovementioned disorders unlikely, we conclude that our patients have a previously undescribed disorder.

Self-reactive cytotoxic gamma delta T lymphocytes in Graves' disease specifically recognize thyroid epithelial cells

In this paper we report the isolation of a self-reactive cytotoxic gamma delta T cell line, 158RE.2, that originates from the T lymphocyte population infiltrating the thyroid gland of a patient with Graves' disease. Functional data using this cell line demonstrate that gamma delta T cells expanded in the thyroid tissue specifically recognize a ligand expressed by thyroid epithelial cells and cell lines of endocrine epithelial origin. The TCR expressed by these gamma delta T cells--V gamma I/V delta 5--is unusual in peripheral blood lymphocytes, and its specificity is clearly different from that observed in a high percentage of gamma delta T cells from PBL, which express the common TCR V gamma 9/V delta 2. The V gamma I/V delta 5 receptor is involved in the recognition of the ligand expressed by the thyroid cells, but not in the NK-like activity also displayed by 158RE.2. These cells express CD8 alpha alpha dimers, which participate in the thyroid ligand recognition but not in the NK-like activity. The epithelial cell recognition is not restricted by classical MHC class I or class II molecules, although the CD8 alpha alpha participation in the recognition suggests the involvement of nonclassical MHC molecules. These are the first data to be presented on self-reacting gamma delta T cells in human epithelium.

Self-reactive cytotoxic gamma delta T lymphocytes in Graves' disease specifically recognize thyroid epithelial cells

In this paper we report the isolation of a self-reactive cytotoxic gamma delta T cell line, 158RE.2, that originates from the T lymphocyte population infiltrating the thyroid gland of a patient with Graves' disease. Functional data using this cell line demonstrate that gamma delta T cells expanded in the thyroid tissue specifically recognize a ligand expressed by thyroid epithelial cells and cell lines of endocrine epithelial origin. The TCR expressed by these gamma delta T cells--V gamma I/V delta 5--is unusual in peripheral blood lymphocytes, and its specificity is clearly different from that observed in a high percentage of gamma delta T cells from PBL, which express the common TCR V gamma 9/V delta 2. The V gamma I/V delta 5 receptor is involved in the recognition of the ligand expressed by the thyroid cells, but not in the NK-like activity also displayed by 158RE.2. These cells express CD8 alpha alpha dimers, which participate in the thyroid ligand recognition but not in the NK-like activity. The epithelial cell recognition is not restricted by classical MHC class I or class II molecules, although the CD8 alpha alpha participation in the recognition suggests the involvement of nonclassical MHC molecules. These are the first data to be presented on self-reacting gamma delta T cells in human epithelium.

Interleukin-7 rescues human activated T lymphocytes from apoptosis induced by glucocorticoesteroids and regulates bcl-2 and CD25 expression

We studied the ability of several interleukins to inhibit the cellular death of IL-2-dependent human T cells deprived of IL-2 testing viability, DNA integrity, and expression of bcl-2 gene product. Our in vitro results showed that the addition of IL-7, and in a far less efficient manner IL-4, augmented the viability of IL-2-dependent T-cell clones of different origin, specificity, and phenotype. Furthermore, IL-7 reduced the percentage of apoptotic T cells inhibiting DNA fragmentation. In addition, IL-7 but not IL-4 was consistently able to suppress the cell death of IL-2-dependent T cells triggered by DEX, a synthetic GC. The suppression of T-cell death triggered by IL-7 was not affected by the addition of anti-IL-2 antibody. Interestingly, IL-7 inhibited the downregulation of bcl-2 gene product expression that appeared on TCCs after IL-2 withdrawal and also shared with IL-2 the ability to induce the upregulation of CD25 antigen on activated T lymphocytes in the presence of DEX. These experiments establish a novel role for IL-7 in regulating viability and GC-induced apoptosis on activated human T cells and suggest that the maintenance of bcl-2 levels is a general mechanism by which interleukins preserve activated T cells from undergoing apoptosis.

Primary midline developmental field. II. Clinical/epidemiological analysis of alteration of laterality (normal body symmetry and asymmetry)

Lubinsky [Am J Med Genet 3:23-28, 1987] has suggested that the properties of the midline involve early determinative informational processes and are related to the midline's position and definition of the body's plane of symmetry. Opitz [Am J Med Genet 21:175-176, 1985, BD: OAS XXIX(1):3-37 1993] has pointed out that the laterality sequences represent a midline developmental field complex. Thus, bilateral left-sidedness (with asplenia) and bilateral right-sidedness (with asplenia) have been considered laterality sequences or syndromes if cause is known. Using the malformed infants registered by the Spanish Collaborative Study of Congenital Malformations (ECEMC), we performed a clinical/epidemiological analysis of the relationship between midline defects and alteration of normal body asymmetry and symmetry. The results support the assumption that both conditions could be consequence of disturbances in the midline primary developmental field.

An additional set of phages to characterize epidemic methicillin-resistant Staphylococcus aureus strains from Spain (1989-92)

In recent years, methicillin-resistant Staphylococcus aureus (MRSA) isolates in Spain have increased dramatically; in 1986 there were only 1.2% MRSA amongst all nosocomial Staphylococcus aureus (SA) isolates, by 1989 this percentage had risen to 44% in some hospital causing a very serious epidemic situation in the country. We have characterized these isolates by direct, reverse and Fisk phage typing and we have also looked for an additional local set of phages to help us to differentiate these strains. We have been able to differentiate an epidemic strain from other MRSA strains which cause sporadic hospital outbreaks, and we have also distinguished between some variants of the epidemic strain.

Ribotyping of Staphylococcus aureus: an assessment using well-defined strains

Ribotyping, with homologous or heterologous (Escherichia coli) r-RNA, of the propagating strains for phages of the international set for strains of Staphylococcus aureus of human origin was undertaken to determine the discrimination of this typing method. Ribotyping could distinguish between strains of different phage groups, but could not distinguish between seven phage group III strains of different phage type. Ribotying may be a useful adjunct to phage typing in S. aureus but is unlikely to replace it as the primary method of epidemiological typing.

ICAM-3, the third LFA-1 counterreceptor, is a co-stimulatory molecule for both resting and activated T lymphocytes

Optimal activation of human T cells mediated by ligation of CD3/T cell receptor (TcR) complex requires co-stimulatory signals. These can be provided by the adhesive interaction between receptor molecules on T cells and their counter-receptors on antigen-presenting cells. Soluble ICAM-3, anti-ICAM-3 and anti-CD3 mAb were utilized to address the role of the ICAM-3/LFA-1 pathway in TcR/CD3-dependent or -independent T cell activation. Immunoaffinity-purified ICAM-3 co-immobilized with suboptimal concentrations of anti-CD3 monoclonal antibody (mAb) stimulated T lymphocytes as monitored by the expression of the lymphocyte activation antigens CD25 and CD69. The mechanism underlaying this activation appear to involve the interaction of ICAM-3 with a beta 2 integrin, likely to be LFA-1, since mAb to the CD18 chain completely inhibited T cell activation. Similar experiments demonstrated that anti-ICAM-3 mAb were able to co-stimulate both resting (cord blood) and activated (T cell clones) T lymphocytes. On the contrary, anti-ICAM-1 mAb were only co-stimulatory for CD25 expression on activated but not on resting T cells. In addition, we have found that some gamma delta T cell clones bearing the V delta 1 segment were activated by direct mAb engagement of ICAM-3 in the absence of TcR/CD3 occupancy. Furthermore, immobilized anti-ICAM-3 mAb also induced development of dendritic processes. In conclusion, our data suggest that ICAM-3 on the surface of both T cells and antigen-presenting cells plays an essential role in the initiation of the immune response.

A novel functional cell surface dimer (kp43) serves as accessory molecule for the activation of a subset of human gamma delta T cells

Kp43 is a cell surface molecule expressed by NK cells, gamma delta T lymphocytes, and a small subset of CD56+ alpha beta T cells. In the present study the distribution and function of Kp43 on gamma delta T cells is described. The expression of Kp43 on freshly isolated gamma delta T-cell populations derived from fetal and adult tissues was biased toward memory V gamma 2+/V delta 2+ T lymphocytes and appeared to be up-regulated after activation. Several gamma delta T-cell clones were derived from different sources. Adult V gamma 2+/V delta 2+ T-cell clones expressed the highest levels of Kp43, V delta 1 T-cell clones derived from periphery expressed moderate levels, whereas some thymus V delta 1 T cells and fetal gamma delta T-cell clones displayed low or undetectable levels of Kp43 molecule. Based on the effect of a specific mAb, this dimer appears to be fully functional as previously shown for NK cells. The stimulation of Kp43+ gamma delta T-cell clones with a combination of anti-CD3 and anti-Kp43 co-immobilized on a solid substratum enhanced both the expression of cell surface CD25 and the secretion of TNF-alpha. The restricted expression and functional activity of the Kp43 dimer suggests that it may play an important regulatory role in activation, selection, Ag recognition, and responsiveness of a subset of gamma delta T cells.

A novel functional cell surface dimer (kp43) serves as accessory molecule for the activation of a subset of human gamma delta T cells

Kp43 is a cell surface molecule expressed by NK cells, gamma delta T lymphocytes, and a small subset of CD56+ alpha beta T cells. In the present study the distribution and function of Kp43 on gamma delta T cells is described. The expression of Kp43 on freshly isolated gamma delta T-cell populations derived from fetal and adult tissues was biased toward memory V gamma 2+/V delta 2+ T lymphocytes and appeared to be up-regulated after activation. Several gamma delta T-cell clones were derived from different sources. Adult V gamma 2+/V delta 2+ T-cell clones expressed the highest levels of Kp43, V delta 1 T-cell clones derived from periphery expressed moderate levels, whereas some thymus V delta 1 T cells and fetal gamma delta T-cell clones displayed low or undetectable levels of Kp43 molecule. Based on the effect of a specific mAb, this dimer appears to be fully functional as previously shown for NK cells. The stimulation of Kp43+ gamma delta T-cell clones with a combination of anti-CD3 and anti-Kp43 co-immobilized on a solid substratum enhanced both the expression of cell surface CD25 and the secretion of TNF-alpha. The restricted expression and functional activity of the Kp43 dimer suggests that it may play an important regulatory role in activation, selection, Ag recognition, and responsiveness of a subset of gamma delta T cells.

The CD26 antigen is coupled to protein tyrosine phosphorylation and implicated in CD16-mediated lysis in natural killer cells

The levels of CD26 expression, their capacity to induce protein tyrosine phosphorylation and their functional implication in natural killer (NK) cytolysis have been studied. It was found that only a small fraction (12-15%) of peripheral NK cells expresses CD26 compared with the high expression (99%) found in NK clones. The protein tyrosine phosphorylation mediated by means of CD26 activation was studied in NK cells treated with the anti-CD26 MoAb 134-2C2, and two new proteins of 50 and 21 kDa appeared phosphorylated in tyrosine residues. To study the influence of CD26 antigen in NK lysis, we analysed the lytic capacity of NK cells stimulated with different anti-CD26 MoAbs or after separation into CD26+ and CD26- subsets and using K562 as target cells. Under these conditions, no differences were found in the chromium release by the target cells. Redirected lysis through CD16 was also measured by arming the effector cells (CD26+ and CD26-) with anti-CD16 antibody and using K562 as target cells. It was found that CD26- cells showed significantly less CD16-dependent lysis than CD26+ cells. These results indicate that CD26 is related to the CD16-dependent lysis but not to NK cytolysis which may be caused by mediation of protein tyrosine phosphorylation.

An epidemic methicillin-resistant strain of Staphylococcus aureus in Spain

During 1990, a strain of methicillin-resistant Staphylococcus aureus became epidemic in Spain and spread in a manner analogous to that of EMRSA-1 in England. Isolates of this strain produced little protein A and were resistant to a number of antibiotics including ciprofloxacin. Beta-lactamase production was encoded by a c. 39 kb plasmid, which also conferred resistance to mercury, cadmium, ethidium bromide and propamidine isethionate. Investigation showed that two variants, separable by supplementary and Fisk phage typing, were circulating. The B variant appeared to spread more readily than the A variant. The opportunity was taken to compare the discriminatory power of traditional typing methods with molecular techniques. The discriminatory power of the molecular techniques used only reached the same level as the traditional methods when double enzyme digestion of total cellular DNA by EcoR I and Cla I was performed.

Functionally distinct subsets of human gamma/delta T cells

To determine if effector subsets exist among human gamma/delta T cells, we examined the cytokine production and cytotoxic activity of gamma/delta T cell clones with different accessory molecule phenotypes, V delta and V gamma gene expression, and J gamma rearrangements. T cell clones bearing gamma/delta T cell receptor produce an array of cytokines like alpha/beta T cell clones. Individual gamma/delta T cell clones produced a characteristic array of cytokines without correlation with V delta or V gamma gene expression. However, when phenotypic subsets were considered, CD4+ gamma/delta clones produced significantly higher levels of interleukin 2 and granulocyte-monocyte colony-stimulating factor compared with CD4-CD8- and CD8+ gamma/delta clones. Similarly, when cytotoxic potential was assessed, CD4+ gamma/delta clones exhibited minimal activity when compared with CD4-CD8- and CD8+ adult peripheral blood gamma/delta clones. We conclude that functionally distinct gamma/delta T cell subsets exist and suggest that these subsets may correlate with expression of the CD4 accessory molecule.

Low IgG2 and polysaccharide response in a T cell receptor expression defect

B lymphocytes require appropriate T lymphocyte cooperation to synthesize immunoglobulins (Ig). Such interaction presumably takes place after engagement of the T cell receptor (TcR) by antigen. The present work addresses B lymphocyte function (and phenotype) in a novel type of immunodeficiency which is characterized by a TcR expression defect. In contrast to expectations, the two affected siblings that were studied displayed normal in vivo antibody responses to both endogenous and exogenous protein antigens. However, they showed impaired responses to certain polysaccharide antigens together with a selective IgG2 deficiency. These results suggest that some polysaccharide responses may be more T cell dependent than previously suspected, and support the notion that T cell dysfunctions (of this or other kind), rather than Ig gene deletions, may be the molecular basis of certain IgG2 deficiencies. To rule out a concomitant gross B cell dysfunction in these individuals, B lymphocyte phenotype and function were assayed in vitro, and found to be normal. A T cell line derived from one of the siblings displayed an abnormal TcR on the cell surface, but it showed several normal TcR-mediated functions. This suggests that the low number of peripheral T lymphocytes that have been found to express low TcR levels in these immunodeficiencies may be operational, and supplying sufficient "help" for the observed normal antibody responses to all tested protein, but not polysaccharide, antigens.

Cefotaxime in the treatment of chronic osteomyelitis caused by gram-negative bacilli

Fifty patients with chronic osteomyelitis due to aerobic or facultative Gram-negative bacilli, alone or in mixed infections with Gram-positive cocci, were treated with cefotaxime. The diagnosis of osteomyelitis was made on the basis of clinical, roentgenographical, isotopic, microbiological and histopathological evidence of infection. Only those patients with infection sensitive to cefotaxime were treated. Most patients received 2 g cefotaxime qid iv for 30-60 days (mean 40 days). Some patients received metronidazole in addition. The following results were obtained at the six month follow-up: 40 patients cured, six improved, no failures and four relapses. The surgical technique had an impact on these results. No clinically important side-effects were encountered, nor were any cefotaxime resistant strains found.

An experimental model of chronic osteomyelitis caused by Escherichia coli treated with cefotaxime

An experimental model in Wistar rats, of osteomyelitis caused by Escherichia coli, was used to evaluate the efficacy of cefotaxime in two treatment regimens of different durations. Four groups of rats were set up: a group of rats receiving short-term treatment (14 days) with subcutaneous cefotaxime (100 mg bd), killed after 56 days; a control group receiving no treatment, killed after 56 days; a group of rats undergoing long-term treatment (28 days) with subcutaneous cefotaxime as above, killed after 70 days and a control group of rats receiving no treatment, killed after 70 days. Analysis of histopathological and microbiological findings revealed significantly better results in the long-term treatment group. No side-effects were observed during treatment or afterwards.

[Influence of bacterial combinations on the post-antibiotic effect]

A study of the post-antibiotic effect (PAE) and letality curves of different concentrations of clavulanic acid, amoxycillin, amoxycillin + clavulanic acid, netilmycin and ofloxacin on mixed cultures of S. aureus and E. coli. The post-antibiotic effect was measured after one hour of exposure of bacteria to antimicrobial and the elimination of the latter by the dilution method. Amoxycillin did not induce PAE on the association. PAE only appeared at high concentrations on S. aureus when evaluated alone. Clavulanic acid induced a greater PAE than amoxycillin. The association clavulanic acid + amoxycillin was synergistic and induced a greater PAE than its components. Netilmycin and ofloxacin were the drugs that induced the greatest PAE on the bacterial association and on its strains independently evaluated.

Isolation and characterization of (gamma, delta) CD4+ T cell clones derived from human fetal liver cells

Lymphocytes isolated from human fetal liver and expanded in vitro in IL-2-containing media reveal the existence of CD4+ gamma, delta T cells. These cells display differential features of double-negative and CD8+ gamma, delta T cells as well as of CD4+ alpha, beta T cells. Thus, they failed to lyse targets in lectin-mediated killing assays and to perform classical helper functions. These results add new information necessary for a better understanding of the physiological role of the gamma, delta T cells.

CD8 is involved in both class I- and class II-induced proliferation of a cytolytic T-cell clone with dual specificity for HLA-B27 and HLA-DR2 antigens

A CD3+ CD4- CD8+ cytolytic T-lymphocyte (CTL) clone, CTL 47, could be induced to proliferate in the presence of exogenous interleukin 2 by either HLA-B27.1+ or HLA-DR2+ cells. B27.1-induced proliferation was strongly and equally inhibited by an anti-B27 and by an anti-CD8 monoclonal antibody (MoAb). DR2-induced proliferation was inhibited by the same anti-CD8 MoAb less efficiently and with a different time course than anti-class II blocking, only being significant when the antibody was added ab initio or very early during the assay. These results indicate that CD8 is essential for class I-induced proliferation but that it also enhances class II-induced stimulation of this CTL clone. It is proposed that the necessary role of CD8 in class I-induced proliferation is related to its interaction with the same class I molecule bound by the T-cell receptor. The accessory role in class II-induced proliferation would be due to an additive effect on the avidity of cell adhesion, resulting from interaction of CD8 with the class I antigens on the stimulator cell, or perhaps to a regulatory role of CD8 as a transducer of early signals for T-cell activation.