Sequencing based typing for HLA-C. Identification of three new alleles: Cw*0307, Cw*0502 and Cw*0504

HLA-C has been described as a transplantation locus in the unrelated bone marrow transplantation setting, and noticeably the number of mismatches between HLA-A,-B,-DRB1 compatible pairs is considerably high. Sequencing based typing (SBT) is an accurate and efficient methodology utilised in the HLA class I and II allele level of resolution. SBT for HLA-C locus was applied on a sample of 40 HLA-A,B,DRB1,DRB3/4/5,DQB1-compatible bone marrow recipient-donor pairs, and 3 new HLA-C alleles have been found. Cw*0307, well defined by serology as Cw3, showed two amino acid changes at the NK motif 77-80 regarding all described Cw*03 alleles, N77K80 instead of S77N80. Two new Cw*05 alleles were described, Cw*0502 properly typed by serology, and Cw*0504 that behaves as a short antigen. Cw*0502 differed from Cw*0501 by only one nucleotide at exon 3, that generated an amino acid replacement at codon 177, K to E. Cw*0504 differs from Cw*0501 by two clustered amino acid positions (114 and 116) placed at the peptide binding site. The rate of new HLA-C alleles found in this small series evidences a high grade of hidden HLA-C diversity in the Spanish population, particularly in the well-defined serologic specificities.

[Neurological alterations related to Crohn's disease]

INTRODUCTION

The incidence of alterations of the central and/or peripheral nervous system in a patient with Crohn s disease (EC) is 33.2%. Casual association may occur in 19.3% of the cases. The disorder of the nervous system may precede the diagnosis of EC.

DEVELOPMENT

We review the main neurological complications of EC. The predominant cerebral vascular pathology is arterial although cases of venous thrombosis have been reported. One of the mechanisms involved is the state of hypercoagulability secondary to thrombocytosis and increase in the factors V, V111 and fibrinogen. In other cases there was confirmation of the presence of antiphospholipid antibodies and lupus anticoagulant, and therefore of an autoimmune mechanisms being involved. Other neurological features include peripheral neuropathy (axonal, demyelinating and autonomic), myopathies, pseudotumor cerebri, papilloedema, psychiatric disorders (anxiety, phobias, depression) and association with syndromes such as multiple sclerosis, Cogan s syndrome, Melkersson Rosenthal syndrome, connective tissue disorders and vasculitis.

CONCLUSION

As well as hypercoagulability being one of the pathogenic mechanisms of cerebral ischaemia, there is alteration of humoral and cellular immunity in patients with EC. This justifies this and other neurological manifestations, and explains its association with other immunity disorders.

[Sjögren's syndrome and multiple sclerosis]

INTRODUCTION

Multiple sclerosis (MS) usually follows a relapsing-remitting course and attacks multiple areas of the central nervous system (CNS). Certain rheumatic diseases, including Sjögren's syndrome (SS), can present with a similar clinical picture.

RESULTS

Two patients out 67 of 100 with MS exhibited xerophthalmia and xerostomia and positive Ro antibodies, thus fulfilling 55 diagnostic criteria. Case 1. A 62-year-old woman developed several episodes of numbress and weakness in her left extremity and ataxia. MRI demonstrated a high-intensity areas in periventricular white matter. Initial laboratory studies failure to demonstrate antinuclear antibodies. Xerostomia and xerophthalmia were apparent. Follow-up laboratory examinations showed elevated ANA, Anti-SSA and anti-SSB. Case 2. A 58-year-old woman was diagnosed as having MS at the age of 53 years. Several high-signal foci on MRI were demonstrated in the white matter. Initial serum findings including autoantibodies were unremarkable. Sicca syndrome was present. Laboratory investigations included elevated anti-SSA, anti-SSARo52 and ANA while anti-SSB was within normal limits.

DISCUSSION

Primary SS is a chronic autoimmune inflammatory disease of unknown etiology. The CNS symptoms are present in 20-25% of the patients with SS. Some patients have a relapsing-remitting course mimicking MS. Focal brain lesions in SS can occur in the cerebral white matter. The features of our patients sufficiently mimicked those of MS and this disorder was the diagnosis in each patient at the time of initial evaluation. SS should be considered in th

Parathyroid hormone-related protein as a renal regulating factor. From vessels to glomeruli and tubular epithelium

Parathyroid hormone (PTH) and PTH-related protein (PTHrP) produce similar biological effects through the PTH/PTHrP receptor. Less is known about the physiological role of PTHrP, which was first identified as the agent of the humoral hypercalcemia of malignancy. Despite the widespread production of PTHrP in healthy individuals, the concentration of the protein is below the detectable limit of current assays, suggesting that PTHrP normally functions locally in an autocrine or paracrine manner. Thus, some differences in their biological activities have been described and they may be related to the presence of different receptors. In this regard, a second receptor that binds selectively to PTH has also been found. Recent studies have demonstrated the expression of both PTH/PTHrP receptor and protein in the renal glomeruli. Moreover, there are convincing data that support a direct role of PTH and PTHrP in modulating renal blood flow and glomerular filtration rate. This multifunctional protein, PTHrP, also has a proliferative effect on both glomerular mesangial cells and tubular epithelial cells. Increases in the expression of PTHrP have been observed in several experimental models of nephropathies, suggesting that PTHrP upregulation is a common event associated with the mechanism of renal injury and repair.

Further biochemical characterization of Mycobacterium leprae laminin-binding proteins

It has been demonstrated that the alpha2 chain of laminin-2 present on the surface of Schwann cells is involved in the process of attachment of Mycobacterium leprae to these cells. Searching for M. leprae laminin-binding molecules, in a previous study we isolated and characterized the cationic proteins histone-like protein (Hlp) and ribosomal proteins S4 and S5 as potential adhesins involved in M. leprae-Schwann cell interaction. Hlp was shown to bind alpha2-laminins and to greatly enhance the attachment of mycobacteria to ST88-14 Schwann cells. In the present study, we investigated the laminin-binding capacity of the ribosomal proteins S4 and S5. The genes coding for these proteins were PCR amplified and their recombinant products were shown to bind alpha2-laminins in overlay assays. However, when tested in ELISA-based assays and in adhesion assays with ST88-14 cells, in contrast to Hlp, S4 and S5 failed to bind laminin and act as adhesins. The laminin-binding property and adhesin capacity of two basic host-derived proteins were also tested, and only histones, but not cytochrome c, were able to increase bacterial attachment to ST88-14 cells. Our data suggest that the alanine/lysine-rich sequences shared by Hlp and eukaryotic H1 histones might be involved in the binding of these cationic proteins to laminin.

Collaborative exercise on the use of FISH chromosome painting for retrospective biodosimetry of Mayak nuclear-industrial personnel

PURPOSE

To investigate within the framework of a multilaboratory study the suitability of FISH chromosome painting to measure so-called stable translocations in peripheral lymphocytes of Mayak nuclear-industrial workers (from the Southern Urals) and their use for retrospective biodosimetry.

MATERIALS AND METHODS

Chromosime analyses were carried out from 69 workers who had received protracted occupational radiation exposures (0.012-6.065 Gy) up to approximately 40 years before blood sampling. Twenty-one unexposed people living in the same area were controls. A multicolour FISH-painting protocol with the target chromosomes 1, 4 and 8 simultaneously with a pancentromeric probe was used to score potentially transmissible chromosome-type aberrations (reciprocal translocations 2B and related 'one-way' patterns I-III according to the S&S classification).

RESULTS

Individual biodosimetry estimates were obtained in terms of these potentially long-term surviving aberration types based on the linear component of a low dose-rate gamma-ray calibration curve produced using identical staining and scoring protocols. For comparison, the workers personal and total background doses were converted to red bone marrow doses. The estimated doses were mainly lower than would be predicted by the calibration curve, particularly at accumulated higher dose levels.

CONCLUSIONS

Owing to the limited life-time of circulating T-lymphocytes, the long-term persistence of translocations in vivo requires the assumption of a clonal repopulation of these naturally senescing cells from the haemopoietic stem cell compartments. Obviously such a replacement cannot be fully achieved, leading to a temporal decline even of the yield of transmissible aberrations types. Assuming further a highly selective capacity of stem cells against any type of chromosomal damage and the fact that one must rely on partial genome findings, the potential of FISH chromosome painting for retrospective dose reconstruction is probably limited to a decade or so after high-level protracted radiation exposure.

Polyphasic taxonomy of the basidiomycetous yeast genus Rhodosporidium: Rhodosporidium kratochvilovae and related anamorphic species

The phenotypic and genetic heterogeneity of the basidiomycetous yeast species Rhodosporidium kratochvilovae was investigated in a group of recent isolates and collection strains. A polyphasic taxonomic approach was followed which included micromorphological studies, nuclear staining, determination of sexual compatibility, physiological characterization, comparison of electrophoretic isoenzyme patterns, PCR fingerprinting, determination of mol% G+C, DNA-DNA reassociation experiments and 26S and ITS rDNA sequence analysis. The results allowed a more natural circumscription of the species, both from the genetic and phenotypic perspectives. The relationships with anamorphic species of the genus Rhodotorula were studied and isolates previously identified as Rhodotorula glutinis were found to belong to Rhodosporidium kratochvilovae. Other isolates included in the study were found to represent members of Rhodotorula glutinis var. dairenensis. Rhodosporidium kratochvilovae was found to include heterothallic strains, besides those already known to be self-sporulating. A total of 17 isolates, which were found to belong to this species, were heterothallic, self-sporulating and anamorphic strains. It is anticipated that integrated polyphasic studies of basidiomycetous yeasts will provide a more coherent classification system and the basis for accurate identification schemes, which in turn are essential for detailed ecological studies.

Pulmonary hypertension in COPD: old and new concepts

Pulmonary hypertension is a common complication in chronic obstructive pulmonary disease (COPD). Its presence and severity is closely related to disease prognosis. Remodelling of pulmonary vessels is the principal causative factor of pulmonary hypertension in COPD. In advanced COPD, pulmonary vascular remodelling is related to the severity of arterial hypoxaemia. However, recent studies have shown that structural abnormalities and alterations of vascular function are also apparent in patients with mild COPD who do not have hypoxaemia and even in smokers with normal lung function. Pulmonary endothelium plays a crucial role in the regulation of vascular tone and cell growth of the vessel wall. Alterations of endothelial function in pulmonary arteries are apparent at the early stages of chronic obstructive pulmonary disease evolution. Potential mechanisms of endothelial damage at these initial stages include the effects of cigarette smoke components and inflammatory changes. The resultant alteration of pulmonary endothelium by these factors might predispose patients with mild chronic obstructive pulmonary disease to further vascular damage by additional factors, such as hypoxaemia, ultimately leading to pulmonary hypertension.

Optimization of culture conditions of Porcellio dilatatus (Crustacea: Isopoda) for laboratory test development

This paper describes the experimental results for optimizing isopod culture conditions for terrestrial ecotoxicity testing. The influence of animal density and food quality on growth and reproduction of Porcellio dilatatus was investigated. Results indicate that density influences isopod performance in a significant way, with low-density cultures having a higher growth rate and better reproductive output than medium- or high-density cultures. Alder leaves, as a soft nitrogen-rich species, were found to be the best-quality diet; when compared with two other food mixtures, alder leaves induced the best results, particularly in terms of breeding success. Guidance regarding culture conditions of isopod species, especially in terms of culture density and diet, is given.

Nonsense mutations in the human beta-globin gene lead to unexpected levels of cytoplasmic mRNA accumulation

Generally, nonsense codons 50 bp or more upstream of the 3'-most intron of the human beta-globin gene reduce mRNA abundance. In contrast, dominantly inherited beta-thalassemia is frequently associated with nonsense mutations in the last exon. In this work, murine erythroleukemia (MEL) cells were stably transfected with human beta-globin genes mutated within each of the 3 exons, namely at codons 15 (TGG-->TGA), 39 (C-->T), or 127 (C-->T). Primer extension analysis after erythroid differentiation induction showed codon 127 (C-->T) mRNA accumulated in the cytoplasm at approximately 20% of the normal mRNA level. Codon 39 (C-->T) mutation did not result in significant mRNA accumulation. Unexpectedly, codon 15 (TGG-->TGA) mRNA accumulated at approximately 90%. Concordant results were obtained when reticulocyte mRNA from 2 carriers for this mutation was studied. High mRNA accumulation of codon 15 nonsense-mutated gene was revealed to be independent of the type of nonsense mutation and the genomic background in which this mutation occurs. To investigate the effects of other nonsense mutations located in the first exon on the mRNA level, nonsense mutations at codons 5, 17, and 26 were also cloned and stably transfected into MEL cells. After erythroid differentiation induction, mRNAs with a mutation at codon 5 or 17 were detected at high levels, whereas the mutation at codon 26 led to low mRNA levels. These findings suggest that nonsense-mediated mRNA decay is not exclusively dependent on the localization of mutations relative to the 3'-most intron. Other factors may also contribute to determine the cytoplasmic nonsense-mutated mRNA level in erythroid cells. (Blood. 2000;96:2895-2901)

Identification by sequencing based typing and complete coding region analysis of three new HLA class II alleles: DRB3*0210, DRB3*0211 and DQB1*0310

The study of HLA class II polymorphism by direct exon 2 DNA sequencing analysis has been established to be a reliable and accurate high-resolution typing procedure. This approach shows some advantages in relation to previous methods, polymerase chain reaction using sequence-specific oligonucleotides (PCR-SSO) and sequence-specific primers (PCR-SSP), basically due to the capability of analysis for the complete sequenced genomic region, including non-polymorphic motifs. DRB3 and DQB1 sequencing based typing (SBT) in unrelated bone marrow donor searching allowed us to detect three new alleles. The complete coding region sequences were characterised from cDNA. Two new DRB3 alleles, DRB3*0210 and DRB3*0211, were described in two Caucasian bone marrow donors. Both sequences showed single point mutations regarding DRB3*0202, producing amino acid replacements at positions 51 (Asp to Thr) and 67 (Leu to Ile), respectively. These two point mutations can be found in other DRB alleles, and suggest that gene conversion would be involved in the origin of both alleles. A new DQB1 sequence was found in a Spanish patient that showed two nucleotide differences, positions 134 and 141, with regard to its close similar DQB1*03011 allele. Only substitution at position 134 provoked amino acid replacement at residue 45, Glu to Gly. This single amino acid change would be involved in the lack of serologic recognition of this new molecule by DQ7-specific reagents.

3-phosphoglycerate dehydrogenase deficiency in a patient with West syndrome

3-phosphoglycerate dehydrogenase deficiency is a severe but treatable disorder of serine synthesis, first described in 1996 (Jaeken et al. 1996a). The patient presented with West syndrome, severe psychomotor delay, failure to thrive, microcephaly, atypical ocular movements, and pyramidal signs. Treatment with oral L-serine abolished seizures and improved psychomotor development, hyperexcitability, head growth, cortical and subcortical hypotrophy, and hypomyelination of the brain on MRI scans. 3-phosphoglycerate dehydrogenase deficiency is a treatable congenital error that probably leads to West syndrome.

Phase II evaluation of a high-dose mitoxantrone based induction regimen in untreated adults with acute myeloid leukemia

To evaluate a regimen including high-dose mitoxantrone in previously untreated adults with AML, 45 patients aged 21-59 (median 41) were given cytarabine, 3 g/m2 days 1-5, mitoxantrone, 80 mg/m2 day 2 and etoposide, 150 mg/m2 days 1,3,5. Post-remission therapy consisted of 5 cycles combining the same agents at reduced doses. Complete remission was seen in 36 patients. The observed 3-year survival is 28%. Cytogenetic pattern and CD34 expression correlated with response and survival. Significant toxicity included myelosuppression, mucositis, diarrhea and hyperbilirubinemia. Ventricular ejection fraction was generally reduced, with clinical cardiac dysfunction in only 2 patients. This high-dose mitoxantrone combination can be administered to young adults with AML with tolerable toxicity and results comparable to those of other dose-intensive regimens.

[Transient global amnesia: a review of 58 cases]

INTRODUCTION

Transient global amnesia (TGA) is a clinical condition in which the etiopathogenesis is still not clear. The most generally accepted theory is of a vascular origin, although epilepsy or migraine have also been considered to possibly be the cause.

OBJECTIVE

To make a retrospective review of the risk factors, etiopathogenesis and clinical characteristics of 58 patients with TGA.

PATIENTS AND METHODS

The variables recorded were compared with those from two control groups: one of healthy individuals and one of patients with transient ischemic attacks (TIA).

RESULTS

The average age of the patients with TGA was 66.01 years. The risk factors included: arterial hypertension (58.62%), dyslipemia (15.51%) and migraine (8.62%). In three patients the EEG showed weak bilateral frontotemporal interference. Cerebral CT scans were done in all cases and were found to be pathological in 23, with lacunar multinfarct the commonest abnormality. With regard to patients with TIA, these were older (66.01 vs 72.94), smoked more (1.72% vs 12.06%) and a previous stroke was more frequent (8.62% vs 31.03%). We did not find differences regarding dyslipemia, atrial fibrillation, arterial hypertension or cardiac ischemia. However, the prevalence of vascular risk factors was significantly higher in patients with TGA as compared to healthy controls.

CONCLUSION

We suggest that the etiopathogenesis of TGA is probably a transient ischemic phenomenon triggered (or not) following an attack of migraine.

Intestinal alphabeta T cells of symptomatic celiac disease patients show oligoclonal TCRBV repertoire but polyclonal rearrangement patterns

Celiac disease is an immunological disease provoked by some cereal proteins in HLA-DQ-mediated susceptible individuals. The role of intestine infiltrating alphabeta T cells in the pathogenesis of the disease has been functionally established. In the present report, we have studied the repertoire of TCRBV genes, spectratype distribution, and CDR3 sequences of intestinal T cell populations isolated from three CD patients at diagnosis and two normal control biopsies. Oligoclonal TCRBV usage was observed both in CD and control samples. However, a much more restricted TCRBV usage was evident in normal mucosa. The use of BV gene families was linked to no dominant rearrangements in CD, while apparent oligoclonal patterns were found in normal biopsies. Only 3 out of 73 sequenced transcripts derived from preponderant TCRBV genes in the three celiac samples were obtained twice. In contrast, only 13 different rearrangements were found out of 32 analyzed in control samples. In spite of the polyclonal behavior of T cells in CD mucosa, some conserved motifs in the CDR3 region were noticed among rearrangements derived from different TCRBV genes and patients. The lack of expanded T cell clones in the damaged tissue could be explained in terms of antigen diversity or by non-specific immunological responses in the symptomatic phase of the disease.

[Incidence of otosclerosis in a subpopulation of Galicia, Spain]

We have made a prospective study of the patients who were analysed for the first time at the Outpatients Department in the Otolaryngology Section of the University Complex Hospital of Santiago de Compostela all along 1997. A whole of 1,050 patients have been included in this study. The most frequent diagnosis were neurosensorial hypoacusis (29.1%), chronic otitis media (27.8%) and in the third place, otosclerosis. This appeared in 83 cases, which represents a 8.7% of the fulfilled diagnosis. The incidence for our health area reached 19 new cases of otosclerosis per 100,000 inhabitants a year. When only the number of stapedectomies were included, it reached a 7.8%. The prevalence of the female population was clear, reaching a 77%. Diagnosed patients' age was from 30 to 50 years, although a considerable percentage (37%) were older. The incidence reached by our studies is higher to other values previously published. We think this responds to the fact that the health system covers all the population and to the importance a good audition is given nowadays.

Inflammatory reaction in pulmonary muscular arteries of patients with mild chronic obstructive pulmonary disease

Endothelial dysfunction and intimal thickening have been shown in pulmonary arteries (PA) of patients with mild chronic obstructive pulmonary disease (COPD). To investigate whether an inflammatory process related to tobacco smoking might be involved in the development of pulmonary vascular abnormalities in COPD, we characterized the inflammatory cell infiltrate and the endothelium-dependent relaxation in PA of 39 patients who underwent lung resection, divided into three groups: "nonsmokers" (n = 7); "smokers," with normal lung function (n = 12); and "COPD" (n = 20). Endothelium-dependent relaxation was assessed in vitro by exposing PA rings to adenosine diphosphate (ADP). Inflammatory cell types were identified by immunohistochemistry. PA of COPD patients developed lower relaxation in response to ADP than nonsmokers and smokers. The number of inflammatory cells was increased in PA of COPD compared with the other two groups. This cell infiltrate was largely constituted by T lymphocytes. The CD8(+) T-cell subset was increased in both smokers and COPD compared with nonsmokers, yielding a reduction of the CD4(+)/CD8(+) ratio. The intensity of the inflammatory infiltrate correlated with both the endothelium-dependent relaxation and the intimal thickness. We conclude that cigarette smoking induces a CD8(+) T-lymphocyte infiltrate in PA, which is associated with the impairment of the vessel's structure and function, suggesting the potential involvement of an inflammatory process in the pathogenesis of pulmonary vascular abnormalities in the early stage of COPD.

[Symptomatic epilepsy: review of 208 patients]

OBJECTIVE

To determine the main etiological mechanisms of symptomatic epilepsy and its frequency according to age.

PATIENTS AND METHODS

We made a retrospective analysis of 208 patients admitted during a period of four and a half years, studying the variables: age, sex and type of seizures: simple partial, secondarily generalized partial, complex partial, tonic-clonic, generalized tonic, and also EEG and neuroimaging.

RESULTS

The main etiological mechanisms found were: vascular (31.25%), alcoholic (12.01%), intracranial disorders (9.61%), traumatic (5.28%), degenerative (5.28%), infectious (2.88%) and cryptogenic (33.65%). In the last group there was an outstandingly large proportion of patients with silent infarcts. When considering vascular epilepsy, those seizures occurring during the acute phase of the stroke (24/65) are differentiated from those of late onset (41/65). In the latter there was a marked predominance of ischemic etiology (48.78% corresponded to extensive infarcts in the territory of the middle cerebral artery; 36.58% were associated with partial infarcts) probably because of the greater frequency of ischemic stroke as compared with hemorrhagic stroke. After the acute phase, the latency was of 10.68 +/- 0.43 months and the most frequent seizures were tonic-clonic (48.78%).

CONCLUSION

In persons under 30 years of age, etiology is multifactorial; between 30 and 50 years of age alcoholic epilepsy (39.53%) and traumatic epilepsy (11.62%) predominate; over the age of 50 years the cause was vascular in 43.5%. In the latter age group there was a high proportion of patients with heraldic seizures.

Characterization of a new HLA-B*38 allele (B*3803) in a Spanish Caucasian individual which is closely related to the Oriental B*38021 and B*39021 alleles

The broad HLA-B16 serologic specificity is divided into B38 and B39 splits associated to Bw4 and Bw6, respectively. Differential serologic variants have been defined for several molecular subtypes of B39 and for B38. We found a Spanish Caucasian individual carrying a B16 Bw4-associated antigen which was not recognized by reagents against B16 splits. Sequencing analysis showed a new B16 subtype termed B*3803. HLA class I sequence-based typing (SBT) analysis demonstrated that B*3803 co-segregates with A*2608 and Cw*1203, forming a common Caucasian haplotype. Sequence comparison with B*38 and B*39 subtypes evidences that although B*3803 is close related to B*3802, it only differs from B*39021 by six clustered nucleotide position in the Bw4/Bw6 motif, and strongly suggests that B*3803 could have evolved from, or be the ancestral gene of the Oriental-associated B*3802 and B*39021 alleles. However, more complex patterns of genetic events should be considered due to the Caucasian background of the B*3803 individual an its associated haplotype.

Immunochemotherapy with interferon-gamma and multidrug therapy for multibacillary leprosy

Treatment for multibacillary leprosy is presently performed with a multidrug therapy (MDT) scheme maintained for 2 years. Leprosy treatment however can benefit from the reduction of length. The lack of interferon-gamma (IFN-gamma) production by lepromatous leprosy (LL) patients' lymphocytes lead us to use this cytokine in the treatment of multibacillary leprosy associated with MDT in the treatment of multibacillary leprosy, and monitor several clinical and immunological parameters during the course of treatment. A total of 20 multibacillary leprosy patients were evaluated, 10 treated with MDT alone, and 10 treated with MDT + 10 daily doses of 2 x 10(6) international units (IU) of recombinant human IFN-gamma/m2 followed by 10 daily doses of 10(7) IU IFN-gamma/m2, intramuscularly, during the first 20 days of MDT. IFN-gamma was well tolerated and did not cause any increase in the rate of leprosy reactions development during treatment. Decrease of bacillary load, fall of anti-Mycobacterium leprae IgG serum antibodies, changes of histological pattern, as well as changes in lymphocyte proliferation assay in response to mitogens (PHA or PWM), M. leprae antigen or PPD was similar in both groups of patients. Among several soluble immunological markers measured before and 30 days after beginning of treatment, levels of soluble IL-2R receptor increased in patients treated with MDT plus IFN-gamma whereas decreased in patients treated with MDT alone. Soluble ICAM-1 levels decreased in the MDT group but did not change in the MDT + IFN-gamma treated patients. Soluble CD4 and soluble CD8 markers did not change significantly in either group of patients. Neopterin, a marker of macrophage activation, increased in all but one patient treated with MDT + IFN-gamma but in none treated with MDT alone, indicating that IFN-gamma was active in vivo. Our findings indicate that despite being able to promote macrophage activation in multibacillary leprosy patients a short course of systemically administered IFN-gamma is not able to change the clinical course of a long standing disease such as leprosy.

Renal expression of parathyroid hormone-related protein (PTHrP) and PTH/PTHrP receptor in a rat model of tubulointerstitial damage

BACKGROUND

PTHrP, which appears to act as a growth/differentiation factor in a variety of tissues, is present in the kidney; however, its role is unclear.

METHODS

The expression of PTHrP and the PTH/PTHrP receptor were investigated by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry in the remnant kidney of uninephrectomized (UNX) rats after protein overloading [1 g/day of bovine serum albumin (BSA)].

RESULTS

Compared with UNX-control rats, proteinuria in BSA-overloaded animals was detected within the first 24 hours and increased during the entire study period (28 days). Kidney examination by light microscopy showed no significant renal lesions at day 1 of BSA treatment, whereas at days 8 and 28, tubular lesions, infiltration of mononuclear cells, and mesangial expansion were observed. PTHrP mRNA expression in the renal cortex was already increased at day 1 (fourfold) and plateaued between days 8 and 28 (12- and 15-fold, respectively) in BSA-overloaded animals compared with UNX-control rats. At day 8, immunohistochemical analysis with two different anti-PTHrP antibodies showed a dramatic increase of PTHrP staining in the damaged proximal and distal tubules from BSA-overloaded rats with respect to UNX-control rats. Moreover, intense PTHrP immunostaining was also observed in glomerular mesangial and endothelial cells in BSA-overloaded rats, but not in the UNX-control rats. A reciprocal decrease of PTH/PTHrP receptor mRNA and immunostaining, without significant changes in the cellular localization (proximal and distal tubule, and glomerular mesangial and epithelial cells) of the PTH/PTHrP receptor positivity was found to occur in the renal cortex of BSA-overloaded rats. At day 8, coinciding with the up-regulation of PTHrP, an increase in the angiotensin converting enzyme and preproendothelin-1 gene expression was observed in the renal cortex of BSA-overloaded rats compared with UNX-control rats.

CONCLUSIONS

These results indicate that PTHrP can be added to the group of genes that are up-regulated in proximal tubular cells in response to intense proteinuria. Our results, together with previous findings, suggest that the vasoactive hormones angiotensin II and endothelin-1 could participate in the PTHrP production in the renal cortex of BSA-overloaded rats. Further experiments are required to clarify the mechanisms of PTHrP up-regulation and its possible role in the response to renal damage in this animal model.

Characterization of a new HLA-B18 allele, B*1806, which lacks expression of the Bw6 epitope

HLA-B18 is a well defined Bw6-associated serologic specificity. Up to now, four different sequences have been characterised in Caucasian populations (B*1801,3,4,5), and one in Orientals (B*1802). We report a new HLA-B18 subtype (B*1806) which was serologically detected in a Spanish Caucasian individual as a B18 Bw4-associated antigen. Complete coding region sequencing showed that B*1806 differs from B*1801 in a unique nucleotide at position 299 (A to T), giving rise to an amino acid replacement in residue 76 (glutamic acid to valine) placed at the alpha1 domain. Therefore, in contrast to the serologic results, B*1806 possesses the canonical Bw6 motif at position 77-83. Subsequent flow cytometric assays proved that B*1806 evidences neither Bw4 nor Bw6 epitopes. Only three additional HLA-B alleles encode valine at codon 76, B*4601, B*7301 and B*5503, and like B*1806, all of them would include a Bw6 motif associated to the negative recognition by Bw6 antibodies. These findings support that valine at position 76 will modify the Bw6 epitope drastically, and suggest that this group of HLA-B alleles would define a third, Bw4 and Bw6-negative, lineage of molecules. Furthermore, valine 76 will also prevent the binding of Bw6 antibodies to those HLA-C antigens with the canonical Bw6 epitope (Cw*1,3,7,8,12,13,14,16).

Immunotherapy and mast cell activation

Tryptase is the more specific markers for mast cell activation and mediators release and can be used as an index of mast cell activation after challenge. Nasal provocation tests have been done in patients allergic to the pollen of Parietaria (pellitory wall) before and after specific systemic immunotherapy and tryptase release evaluated in nasal lavage fluid. After specific immunotherapy the concentration of tryptase in nasal lavage was significantly decreased to all the concentrations used in challenge and the peack of tryptase release was delayed. These results confirm that assays of tryptase in nasal fluid after nasal provocation are a reliable markers of mast cell activation. Immunotherapy with specific allergen decreases mast cell reactivity to the same allergen.

[The referral of hospitalized patients with cerebrovascular pathology. Where, when and why. A cross-sectional multicenter study of the referral of patients with ischemia and predisposing factors]

OBJECTIVES

Referral of patients with ictus on discharge from hospital is a daily problem for neurologists, both because of the suitability of one place or another for maximum recovery of the patient and because of the effect on average stay, complications and use of resources. The aim of this study was to determine where and when patients with ictus were referred and what factors affect whether a patient goes to one place or another.

PATIENTS AND METHODS

A transversal multicentric study (3 months) using a questionnaire was sent to all Insalud hospitals in Aragon, recording data of 128 patients from four hospitals. There were questions on medical, functional, demographic and socio-economic factors which might affect referral.

RESULTS

On discharge 20% of the patients did not return to their own homes. In 50% of the cases where patients went to a supporting hospital (SH) socio-economic factors were decisive and in 20% were the only cause. Referral to SH was related to functional state and type of ictus, need for nursing care or rehabilitation, age, sex, marital status and place of residence.

CONCLUSIONS

Apart from clinical criteria, many socio-economic factors determine the need for referral of patients to one place or another.

Characterization and distribution of HLA-B*5002 in a Spanish population sample

HLA-B45, in contrast to B44, does not show molecular polymorphism. We have found a group of Caucasian Spanish individuals, serologically typed as B45, showing an unexpected HLA-B12 PCR-SSO subtyping pattern. Complete coding region sequencing and B45 subtyping by PCR-SSO demonstrated that the B45 serologic specificity is constituted by two molecular alleles: B*4501 and B*5002. B*5002 is recognized by polyclonal and monoclonal allosera against B12 and B45, whereas it is not detected by B21, B49, or B50 reagents, providing a new example of poor correlation between serology and structure. B*5002 explains an important subset (18%) of the B45-positive individuals of the Spanish population studied, and almost half are included in a very infrequent haplotypic association, Cw6-B*5002-DRB1*0406-DQA1*03-DQB1*0402.

Complete coding sequence of HLA-B*2712: a serologic B27-negative antigen associated to Bw6

We report the complete coding sequence of a new HLA-B27 subtype, B*2712, which was found in a Caucasian Spanish family within the chromosome A2-Cw2-B*2712-DR15-DQ6. B*2712 was first detected as a segregating B blank Bw6-associated antigen. Extensive serologic analysis demonstrated that this new B27 subtype was not recognised by any of the B27-monospecific antibodies, giving positive reactions only with some monoclonal reagents against B40 or B27,40. Sequencing analysis showed a high similarity with B*2708, only differing in three clustered amino acid residues at positions 69 to 71 located in the alpha helix of the alpha1 domain. Residues 69 and 71 point towards the T-cell receptor, while amino acid 70 points to the antigen binding site. Loss of the conserved structure of pocket B as well as the differentiated pocket F configuration suggests that B*2712 does not confer ankylosing spondylitis susceptibility. Misleading serologic definition supports the usefulness of DNA-typing methods to complement HLA class I typing.

Production of host-protective (IFN-gamma), host-impairing (IL-10, IL-13) and inflammatory (TNF-alpha) cytokines by PBMC from leprosy patients stimulated with mycobacterial antigens

The production of IFNgamma, IL-10, IL-13 and TNFalpha was determined using PBMC from 7 tuberculoid (TT) and 7 lepromatous leprosy (LL) patients, after stimulation with several mycobacterial antigens, in an attempt to characterize the cytokine responses to these antigens. The results showed that TT patients displayed higher IFNgamma levels than LL patients with the mycobacterial antigens tested, but no differences in IL-10 production were observed between the two groups. MLSC antigen was associated with the lowest IFNgamma production in TT and LL groups. Only BCG could be identified with stimulation of IFNgamma production in some LL patients. The mycobacterial antigens SP+, SP- and BCG were associated with higher TNFalpha production in patients and controls, suggesting that these antigens could be involved in immunopathological effects. Our findings showed that the antigens tested were associated with a heterogeneous cytokine production in leprosy patients. Further studies are required to establish if an individual antigen can be identified as inducing a protective immune response in leprosy.

HLA-B14 subtyping by semi-nested PCR-SSP and haplotype distribution in a Spanish population

HLA-B14 serological subtyping is very limited probably due to the internal position of the unique amino acid residue that differentiates B64 and B65 molecules. In order to carry out an accurate B14 subtyping we have designed a semi-nested PCR-SSP procedure that can differentiate B*1401 and B*1402 in any HLA-A, -B or -C antigen combination. A panel of 133 B14-positive and 31 B14-negative healthy and unrelated Spanish individuals were studied. Additionally, 45 B14-bearing haplotypes (-A,-B,-C,-DRB1,-DRB3/DRB4/DRB5,-DQA1,- DQB1) were available through family studies. The relative frequencies of HLA-B14 subtypes were 74% for B*1402 and 26% for B*1401, in agreement with those found in other Central European populations, but differing from those in Wales, where the relative presence of B64 goes to 41%. A total of 11/17 and 18/28 different haplotypes for B*1401 and B*1402, respectively, were identified. Both alleles showed the strongest association to Cw8 (43/45), indicating a primary ancestral B14-Cw8 association. However, B14 subtypes evidenced very distinguishable haplotype distributions. B*1401 is strongly associated with the common HLA class II haplotype DRB1*0701-DQA1*0201-DQB1*02 (13/17), while B*1402 is mainly associated to DRB1*0102 (16/28). Three major haplotypes were identified: A32-Cw8-B*1401-DR7-DQ2 (5/17), A33-Cw8-B*1402-DRB1*0102-DQ5 (5/28) and A2-Cw8-B*1402-DRB1*0102-DQ5 (5/28).

Identification by polymerase chain reaction and hybridization with sequence-specific oligoprobes and complete exon-2 cDNA sequencing of a new DRB1 (DRB1*1131) allele

HLA-DRB1 is the most polymorphic gene described so far, and their encoded molecules disclose a major role in allogeneic responses. We describe in this report a new DRB1 allele in a Spanish Caucasian bone marrow donor, initially defined by PCR-SSO as a DRB1*11-like allele. Complete exon 2 cDNA-sequencing reveled that this allele was identical to DRB1*1119 except for a single substitution at position 178, which generates an amino acid change (Tyr-His) at position 60. This residue is shared by several DRB1*14 subtypes and DRB1*0808. The new allele was officially named DRB1*1131.

HLA-B44 subtyping in a Spanish population: further evidence of Caucasian population diversity

HLA-B44 is the most frequent HLA-B allele in Caucasian populations. Several B44 subtypes, B*4402-B*4406, have been identified in individuals with this ethnic origin. Mismatches among B44 subtypes have been described as major targets for allogeneic responses in bone marrow transplantation. We have developed a PCR-SSO method, based on a B12- specific DNA amplification of exon 2 through exon 3 and subsequent non radioactive hybridization with eight probes, which allow us to discriminate all B12 homozygous combinations. We applied this method to determine the frequency of B44 subtypes in a Spanish population, as well as their HLA-A,-C,-DRB1,-DRB3/DRB4/ DRB5,-DQA1 and -DQB1 associated haplotypes. A total of 141 healthy unrelated Spanish individuals and 31 B44-bearing haplotypes were investigated. Four B44 alleles were identified, B*4402 (33%), B*4403 (66%), B*4404 (0.7%), and B*4405 (0.7%). Haplotype analysis showed a clear differentiated distribution pattern for the two major B44 subtypes. B*4402 is associated with Cw5 (11/13) and A2 antigens (10/13). In contrast, B*4403 is mainly found together with DRB1*0701 (14/16). An inverted B*4402/B*4403 frequency in comparison with other European and North American Caucasian populations, revealed the existence of an extended haplotype diversity between populations of the same ethnic origin. Apart from anthropological studies, high resolution typing for HLA class I antigens presenting molecular polymorphism will be of great relevance in unrelated bone marrow transplantation.

[Neonate and infant heart transplantation]

PURPOSE

Heart transplantation has offered children with complex congenital heart diseases and severe cardiomyopathies a chance for survival. The present article was written to show the three year experience of this procedure at the Instituto do Coração-HCFMUSP.

METHODS

The methodology used was based on heart transplant indication criteria, inclusion criteria for donors, postoperative management, immunosuppression and prophylaxis as well as treatment of potential complications.

RESULTS

From November 1992 to November 1995, 11 children, aged 12 days old to six years (mean 2.5 years) underwent transplantation. Sixty percent of recipients were male; weight ranged from 3.5 to 17.8 kg (mean 10.3 kg). The mean age of donors was 4.4 years (a range of three weeks to ten years), 80% male, weight ranging from 3.8 to 20 kg (median 14.3 kg). The survival rate was 91% and the remaining 10 children are doing well. The most important complications were systemic hypertension, acute rejection and infection. The number of rejections and infections per patient were 3.5 and 4.7 episodes, respectively. The follow-up was between one month to three years (average 16 months).

CONCLUSION

In this experience, heart transplantation has given an additional opportunity for children with complex congenital heart diseases and cardiomyopathies, with a survival rate of 91% in three years.

Jugular thrombophlebitis complicating bacterial pharyngitis (Lemierre's syndrome)

Lemierre s syndrome is a rare syndrome caused by Fusobacterium necrophorum, a gram-negative anaerobic organism that normally inhabits the oropharynx. The syndrome follows primary oropharyngeal infection and affects previously healthy adolescents in a characteristic manner with fatal results if left untreated. The authors present two cases seen at their institution and discuss the clinical and radiologic features of the syndrome, along with considerations for patient management.

Two distinct ATP receptors activate calcium entry and internal calcium release in bovine chromaffin cells

ATP, an established neurotransmitter, causes elevation of cytosolic Ca2+ and catecholamine secretion when applied to chromaffin cells in the intact adrenal gland. The ATP-induced rise in Ca2+ is due both to release from internal stores and to entry across the plasma membrane. The latter source of Ca2+ causes secretion; the primary role of Ca2+ released from internal stores remains undetermined. In this article, we have studied the nucleotide specificity for activating the two types of Ca2+ increases. The agonist potency order for the increase in fluorescence from fura-2-loaded chromaffin cells due to release of Ca2+ from internal stores is ATP = UTP > ADP > 2-methylthio-ATP, alpha, beta-methylene ATP, identifying the receptor as a P2u purinoceptor. The potency order for secretion is 2-methylthio-ATP > ATP > alpha, beta-methylene ATP, ADP, UTP, placing the receptor in the P2Y subtype. Thus, two distinct receptors are responsible for Ca2+ release and secretion. Agonists were more effective in the absence of extracellular Mg2+, suggesting that ATP uncomplexed with divalent cations binds preferentially to both receptors. The low response of both receptors to ADP distinguishes them from the ATP receptor on these cells that inhibits voltage-dependent Ca2+ current and secretion.

[Revision of stapedectomy (110 ears)]

We have carried out a retrospective study of 110 ears in patients affected with otosclerosis who underwent revision of stapedectomy, from 1979 to 1991, because they did not achieve hearing improvement or still presented persistent dizziness after primary stapedectomy. In our series, the most common causes of surgical failure after the first surgery are: displacement of the prosthesis (36.3%), ossicular chain alterations (21.8%) and regrowth of otosclerotic bone in the oval window (19.9%). One year after surgery, hearing test was compared with preoperatory tonal audiometry, finding and improvement in 48.1% (closure of 20 dB HL or more of the air-bone GAP), no changes in 43.6% and deterioration of the audition in 8.1%. Finally, we give some advises to prevent hearing loss in the revision of stapedectomy.