High-gain 1.3 μm GaInNAs semiconductor optical amplifier with enhanced temperature stability for all-optical signal processing at 10 Gb/s

We report on the complete experimental evaluation of a GaInNAs/GaAs (dilute nitride) semiconductor optical amplifier that operates at 1.3 μm and exhibits 28 dB gain and a gain recovery time of 100 ps. Successful wavelength conversion operation is demonstrated using pseudorandom bit sequence 2⁷-1 non-return-to-zero bit streams at 5 and 10  Gb/s, yielding error-free performance and showing feasibility for implementation in various signal processing functionalities. The operational credentials of the device are analyzed in various operational regimes, while its nonlinear performance is examined in terms of four-wave mixing. Moreover, characterization results reveal enhanced temperature stability with almost no gain variation around the 1320 nm region for a temperature range from 20°C to 50°C. The operational characteristics of the device, along with the cost and energy benefits of dilute nitride technology, make it very attractive for application in optical access networks and dense photonic integrated circuits.

Multi-format all-optical processing based on a large-scale, hybridly integrated photonic circuit

We investigate through numerical studies and experiments the performance of a large scale, silica-on-silicon photonic integrated circuit for multi-format regeneration and wavelength-conversion. The circuit encompasses a monolithically integrated array of four SOAs inside two parallel Mach-Zehnder structures, four delay interferometers and a large number of silica waveguides and couplers. Exploiting phase-incoherent techniques, the circuit is capable of processing OOK signals at variable bit rates, DPSK signals at 22 or 44 Gb/s and DQPSK signals at 44 Gbaud. Simulation studies reveal the wavelength-conversion potential of the circuit with enhanced regenerative capabilities for OOK and DPSK modulation formats and acceptable quality degradation for DQPSK format. Regeneration of 22 Gb/s OOK signals with amplified spontaneous emission (ASE) noise and DPSK data signals degraded with amplitude, phase and ASE noise is experimentally validated demonstrating a power penalty improvement up to 1.5 dB.

Non classical congenital adrenal hyperplasia due to 21-hydroxylase deficiency in families from a Greek island with a closed society

In young members of a large family from a Greek island with a closed society, clinical and hormonal symptoms of 21-OH deficiency (CAH) were present. To discriminate those affected from those unaffected, we measured the basal and ACTH stimulated 30 values of 17-hydroxyprogesterone (17-0HP) progesterone (P) and cortisol (F) in combination with HLA-phenotypes in 25 out of 40 members of this family. The indices of the Gutai30-min assessment (17-0HP+P response to ACTH testing at 30 min), GF (F response at 30 min) and the ratio GF30/Guai30 named the Marina index were evaluated. The Marina index showed a very statistically significant difference among the three groups (p < 0.001). HLA phenotypes of the members of groups A and B showed a powerful association with B14, DR1, B7, and B35 phenotypes that were related with 21-OH/CAH. In conclusion, in our study population, a high incidence of a clinically asymptomatic form of 21-OHdef was found only after the ACTH stimulation test. The Marina index seems to be of high diagnostic value in classifying disease severity.

A Phase I Study of the Optimized Cryptic Peptide TERT572Y in Patients with Advanced Malignancies

OBJECTIVE

It was the aim of this study to evaluate the safety of the optimized cryptic peptide TERT(572Y) in pretreated patients with advanced cancer.

METHODS

Nineteen patients with progressive and chemotherapy-refractory tumors received escalated doses (2-6 mg) of 2 subcutaneous injections of the optimized TERT(572Y) peptide followed by 4 subcutaneous injections of the native TERT(572) peptide every 3 weeks. Both TERT peptides were coinjected with adjuvant Montanide ISA51. Toxicity was evaluated every 3 weeks and peptide-specific CD8+ cells were detected by flow cytometry using TERT(572Y) tetramers.

RESULTS

Fourteen out of 19 patients completed the vaccination program. No grade III/IV toxicity was observed. Grade I anemia was observed in 4 patients and local skin reaction at the injection site in 11 patients. Other nonhematologic toxicities were mild, and no late toxicity was observed after a median postvaccination follow-up period of 10.7 months. There was no dose-limiting toxicity. Peripheral blood TERT(572Y)-specific CD8+ lymphocytes were detected in 13 out of 14 evaluable patients after 2 injections with the optimized TERT(572Y) peptide. There was no complete or partial response, but 4 patients (21%) with persistent TERT(572Y)-specific CD8+ experienced stable disease for a median of 10.5 months.

CONCLUSION

TERT(572Y) peptide vaccine is well tolerated and effective in eliciting specific TERT(572Y) CD8+ lymphocytes in pretreated cancer patients, demonstrating that cryptic peptides could be used in cancer immunotherapy.

European genetic study on rheumatoid arthritis: is there a linkage of the interleukin-1 (IL-1), IL-10 or IL-4 genes to RA?

The genetic predisposition for rheumatoid arthritis (RA) is only partly explained by the HLA locus and most genetic factors involved in the susceptibility (and/or severity) of the disease await further identification. The first European genome scan in RA families provided suggestive evidence for linkage with a region (3.1/3q13) on chromosome 3, but many other potential RA susceptibility genes have yet to be analysed.

AIMS

To perform a linkage analysis with microsatellite markers located in the vicinity of the interleukin-1 (IL-1) gene superfamily, the IL-10 gene and the IL-4 gene cluster which might be considered putative candidate loci for RA.

METHODS

107 Caucasoid European RA sibpairs from 90 nuclear families were genotyped for markers flanking the genes for the IL-1 superfamily, IL-10 and the IL-4 gene cluster. Linkage analysis based on the identity by descent (IBD) in affected siblings was analysed with the program SIBPALNA. Affected sibpairs were stratified according to the identity by state (IBS) for three markers in the HLA region (DRB1 oligotyping, D6S276 and TNFa microsatellites) and to the presence/absence of erosive disease on X-ray examination.

RESULTS

Analysis of the whole family set showed an excess of allele sharing for markers of the IL-1 gene cluster (IBD 60%; P = 0.012) but not for IL-10 or IL-4. After stratification, the evidence of linkage to IL-1 was restricted to HLA concordant sibpairs (n = 32; IBD 70%; P = 0.006). Some evidence of linkage to IL-10 was also observed in HLA concordant sibpairs (IBD 66%; P = 0.03) and in sibpairs with erosive disease (n = 61; IBD 62%; P = 0.02).

CONCLUSIONS

We found suggestive evidence of linkage of RA to the IL-1 locus. The increased linkage to IL-1 and IL-10 in HLA-identical sibs suggests a possible interaction between these cytokines and the HLA loci. Moreover IL-10 could interact with HLA factors in predisposing to erosive disease. These results need to be tested in additional families for consistency and replication.

Noninherited maternal antigens do not increase the susceptibility for familial rheumatoid arthritis. European Consortium on Rheumatoid Arthritis Families (ECRAF)

OBJECTIVE

It has been proposed that noninherited maternal HLA-DR antigens (NIMA) might play a role in the susceptibility for rheumatoid arthritis (RA). This hypothesis has not been thoroughly tested in patients with familial RA, in whom genetic factors, either inherited or not, might have stronger influence than in patients with sporadic RA. We investigated the NIMA hypothesis in a large cohort of European patients with familial RA.

METHODS

The distribution of NIMA, noninherited paternal antigens (NIPA), and inherited HLA-DR antigens was assessed in patients with familial RA from all family sets collected from 1996 onwards by the ECRAF. HLA-DRB1 oligotyping from patients and all available nonaffected siblings and parents was carried out. Familial RA was defined by the presence of at least 2 affected first-degree relatives in the same family. The frequencies of HLA-DR NIMA and NIPA were compared using odds ratios after stratification for HLA-DR*04, *0401, and/or *0404 and shared epitope (SE) status. NIMA/NIPA that coincided with inherited parental HLA-DR antigens were considered redundant and were excluded from analysis.

RESULTS

NIMA and NIPA could be analyzed in 165 RA patients with familial RA and 84 nonaffected siblings. Patients were predominantly female, rheumatoid factor positive, and had erosive disease (81, 75, and 84%, respectively). Possession of HLA-DR*04 and *0401/*0404 alleles tended be more frequent in patients than in nonaffected siblings but this did not reach statistical significance. SE possession was similar in patients and healthy siblings, although the former had a double dose SE more often (37.6 vs 17.8%; p = 0.002). Transmission of SE encoding alleles from parents to offspring was skewed only in patients [OR (95% CI) 3.56 (2.55-4.95) vs 1.16 (0.75-1.79) in nonaffected siblings]. Using the NIPA as control, the frequencies of HLA-DRB1*04, *0401/*0404, and SE positive NIMA were not increased in patients lacking these susceptibility alleles. The frequencies of NIMA encoding susceptibility alleles in DR*04 and *0401/*0404 negative patients were lower than in nonaffected siblings.

CONCLUSION

Our results corroborate the association between RA and inherited SE alleles and do not support a role for noninherited HLA-DR maternal antigens in the susceptibility for familial RA.

Noninherited maternal antigens do not play a role in rheumatoid arthritis susceptibility in Europe. European Consortium on Rheumatoid Arthritis Families

OBJECTIVE

It has been proposed that noninherited maternal antigens (NIMA) (HLA-DR antigens) might play a role in susceptibility to rheumatoid arthritis (RA), especially in patients who are not genetically predisposed, such as those who are HLA-DR4 and/or shared epitope (SE) negative. The present study was undertaken to test the NIMA hypothesis in a large cohort of European RA patients assembled by the European Consortium on RA Families (ECRAF).

METHODS

HLA-DRB1 oligotyping was performed in families of European RA patients for whom both parents were alive. These families were consecutively recruited by the ECRAF between 1996 and 1998, for association studies. The frequencies of HLA-DR NIMA were compared with those of the noninherited paternal antigens (NIPA) after stratification for HLA-DR*04, *0401 and/or *0404, and SE status. NIMA or NIPA that coincided with inherited HLA-DR antigens were considered redundant and excluded from analysis. Calculations concerning the whole group and restricted to patients lacking parental RA were performed.

RESULTS

One hundred seventy families from France (n = 81), Belgium (n = 23), Spain (n = 24), Italy (n = 19), Portugal (n = 14), and The Netherlands (n = 9) were oligotyped. The group of probands was predominantly female (88%), positive for rheumatoid factor, DR*04, and SE (71%, 58%, and 75%, respectively), and had erosive disease (75%). Parental RA was reported in 21 families. Using the NIPA as control, the frequency of HLA-DRB1*04, *0401 and/or *0404-, or SE-positive NIMA was not found to be increased in patients lacking these susceptibility alleles. The same was true when the 21 probands with parental RA were excluded from analysis. In DRB1*04-positive patients, we found no evidence of a relevant effect of HLA-DR3 or DR6 in the NIMA.

CONCLUSION

Our results do not support the notion that noninherited maternal antigens have a role in susceptibility to RA in the offspring.

Association of heart failure in homozygous beta-thalassemia with the major histocompatibility complex

BACKGROUND

In beta-thalassemia major, heart failure primarily affecting left ventricular systolic function is the most common complication and cause of death. Apart from iron deposition, it has been recently reported that myocarditis might be another contributing factor in the pathogenesis of acute or chronic heart failure, acting possibly through an autoimmune mechanism. In an attempt to assess the role of immunogenetic factors in the development of heart failure associated with beta-thalassemia major, we studied the frequency of major histocompatibility antigens/alleles A, B, DR, and DQ in homozygous beta-thalassemic patients with and without heart failure primarily affecting the left ventricle.

METHODS AND RESULTS

Forty-five consecutive unrelated Greek patients with homozygous beta-thalassemia and left-sided chronic heart failure were studied. Fifty-eight unrelated Greek patients with homozygous beta-thalassemia without heart failure and 130 unrelated Greek healthy controls were also studied. In all subjects, class I HLA-A and -B typing was performed by the complement-mediated lymphocytotoxicity assay, whereas class II HLA-DR and -DQ typing was performed by polymerase chain reaction. HLA-DRB1*1401 allele frequency was significantly increased in patients with beta-thalassemia major without left-sided heart failure compared with those with heart failure (corrected P [P(c)]=0. 02, odds ratio 0.1) and healthy controls (P(c)=0.001). HLA-DQA1*0501 allele frequency was increased in patients with heart failure compared with patients without heart failure (P(c)=0.04, odds ratio 14) and healthy controls (P(c)=0.004).

CONCLUSIONS

Differences exist in the immunogenetic profile between homozygous beta-thalassemic patients with and without left-sided heart failure, raising the possibility that genetically defined immune mechanisms may play an important role in the pathogenesis of heart failure in beta-thalassemia.

Nationwide collaborative study of HLA class II associations with distinct types of juvenile chronic arthritis (JCA) in Greece

The aim of this study was to investigate the association of different groups and subgroups of juvenile chronic arthritis (JCA) with HLA class II (DR, DP, DQ) alleles and/or haplotypes. Groups and subgroups were mainly distinguished on the basis of the type of onset, the course and complications of the disease, and some predefined disease markers according to the criteria proposed by the ILAR Standing Committee (Chile, 1994). On the basis of these criteria the following five JCA groups and their subgroups were included in the study: (1) define systemic onset (n = 25) and systemic progressing to persistent arthritis (n = 14); (2) JCA of oligoarthritis onset (O-JCA, n = 124) and of oligoarthritis onset and course (n = 98), O-JCA of early (< 6 years) or late (> 6 years) onset (EOO-JCA n = 71 and LOO-JCA n = 44), O-JCA with ANA positive (n = 69) or negative (n = 55) and O-JCA progressing to extended arthritis (n = 22); (3) JCA of polyarthritis onset (P-JCA) with rheumatic factor (RF) negative (n = 29), and P-JCA RF negative with antinuclear antibodies (ANA) positive (n = 13) or negative (n = 16); (4) JCA complicated with chronic anterior uveitis (CAU, n = 32); (5) juvenile psoriatic arthritis (n = 20). To assess the HLA allele frequencies in the above 223 Greek children with JCA, these frequencies were compared to those of 98 age-matched and 250 adult controls. The main findings were the following. A common HLA-DRB1* allele was not involved in the JCA groups and subgroups studied; on the other hand, the DQA1*0501 allele was found to be associated with different JCA groups/subgroups (O-JCA, P-JCA RF-negative ANA-positive, JCA with CAU), probably suggesting a closer relationship of this locus with the immunogenetic background of JCA. The DPB1*0201 allele was associated with the development of either EOO-JCA or CAU. Susceptibility to CAU was stronger when the DPB1*0201 was combined with the presence of DRB1*13. Another allele, DQB1*0301, was also associated with O-JCA and CAU. Finally, no specific HLA class II allele was found to be related to the presence of ANA or psoriatic lesions or to the severity of the arthritis. Our findings suggest that the wide clinical and laboratory spectrum of JCA is associated with an immunogenetic background that is linked with HLA alleles of more than one locus. Some of them, such as the DPB1*0201 allele, confer susceptibility to certain clinical onsets and courses or complications of the disease. The rapidly advancing techniques of typing of DNA profiles may lead to more definite conclusions.

Association of MICA gene and HLA-B*5101 with Behçet's disease in Greece

PURPOSE

Behçet's disease (BD) is known to be associated with HLA-B51 in many different ethnic groups. Recently MICA, a member of a novel family of the human major histocompatibility complex (MHC) class I genes termed MIC (MHC class I chain-related genes), was identified near the HLA-B gene, and a triplet repeat microsatellite polymorphism was found in the transmembrane (TM) region. Because a strong association with BD of one particular MICA-TM allele, A6, was shown in a Japanese population, the present study was conducted to investigate microsatellite polymorphism in Greek patients with BD to know whether this association is generally observed in BD occurring in other populations.

METHODS

Thirty-eight Greek patients with BD and 40 ethnically matched control subjects were examined for MICA microsatellite polymorphism using polymerase chain reaction (PCR) and subsequent automated fragment detection by fluorescent-based technology.

RESULTS

Similar to the Japanese patients with BD, the phenotype frequency of the MICA-TM A6 allele was significantly increased in the Greek patients with BD (50.0% in control subjects versus 86.8% in BD cases), with an odds ratio (OR) of 6.60 (P = 0.0012). The MICA-A6 allele was found in a high frequency both in males and females (weighted OR = 6.68; P = 0.0017). No association was found between the A6 allele and several disease features. A strong association exists between the MICA-TM A6 allele and the B*5101 allele in both the control subjects and patients with BD (weighted OR = 44.39; P = 0.0000023).

CONCLUSIONS

This study revealed in Greek patients a strong association of BD with a particular MICA-TM allele, MICA-A6, providing insight into the molecular mechanism underlying the development of BD.

HLA-B*5101 in Greek patients with Behçet's disease

Behçet's disease (BD) is a recurrent systemic vasculitis of unknown etiology. Genetic factors and infectious agents seem to be related to the etiology and pathogenesis of the disease. BD is strongly associated with HLA-B51 antigen in many ethnic groups. As there are differences in HLA profile in different ethnic groups, we designed this case-control study to examine the association of HLA-B51 alleles and BD as well as to investigate the influence of sex, age at development of the International Study Group (ISG) for Behçet's Disease criteria and certain features of disease severity on the strength of this association. The study includes 62 Greek BD patients who fulfill the ISG criteria for Behçet's disease and 87 controls. Serological HLA Class-I typing was performed by standard microlymphocytotoxicity technique. HLA-DNA typing for the B5 group was performed in all B51 subjects and controls by PCR-SSO. Allele B*5101 was found in 80% of BD patients and in 26% of controls (odds ratio (OR) 10.48, p < 10[-6]). Males who carry this allele have a higher risk than females for BD (OR 16.97 and 5.74 respectively). B*5101 predisposes to BD at a younger age in both sexes and to the development of erythema nodosum (OR = 11, p = 0.004). This was confirmed by multiple logistic regression analysis. A weak but not significant association was found between B*5101 and uveitis (OR = 2). No association was found between B*5101 and vasculitis or skin lesions in either sex. It was concluded that in the Greek population allele B*5101 is a predisposing marker for BD, as in most ethnic groups, and that this allele predisposes to the development of the disease at a younger age in both sexes and to the development of erythema nodosum.

HLA-DRB1 alleles in Greek rheumatoid arthritis patients and their association with clinical characteristics

The association of certain HLA-DRB1 alleles in Green rheumatoid arthritis (RA) patients with several features of the disease, the gender of the patient and the age at onset was investigated. This case control study includes 86 Greek RA patients and 130 healthy controls unrelated to the patients. HLA typing was performed by polymerase chain reaction (PCR) and hybridization with sequence-specific oligonucleotide (SSO) probes. HLA-DR4 was significantly increased in RA patients. The alleles *0101, *0401, *0405 and *1001 were associated with a higher risk of RA. The *0408 allele was absent from our patients. Sixty-five per cent of RA patients carried the 'sharp epitope' (SE) compared with 31.5% of controls. The risk for RA in individuals carrying a single allele positive for SE was 2.85 times higher, and for those carrying two alleles positive for SE 8.57 times higher, than in SE-negative individuals. The risk was higher in those carrying the *0401 allele, followed by *0405 and *0101, while the genotype *0401/*0404 was absent. Alleles positive for SE comprise a predisposing factor for RA at an early age, particularly in men, and are associated with positive rheumatoid factor, nodules and erosions.

HLA class II polymorphism and IDDM susceptibility in the Greek population

The frequencies of HLA-DQA1, DQB1 and DRB1 alleles were compared between 50 Insulin-Dependent Diabetes Melitus (IDDM) patients and 49 healthy controls in the Greek population. Statistically significant difference in the frequencies of HLA-DQA1*0501-DQB1*0201 (P = 10(-4)), DQA1*0301-DQB1*0201 (P = 0.01) and DQA1*0301-DQB1*0302 (P = 0.001) were observed. The DRB1*0405-DQA1*0301-DQB1*0201 was the only DR, DQ combination significantly associated with the disease. The unexpected increase of DRB1*0405 observed in the Greek IDDM may suggest as reported in Chinese and Japanese IDDM a contribution of DR beta and DQ alpha in susceptibility. Moreover, in contrast to the Asians, in the Greek, the DR beta, DQ alpha are found with the usual DQ beta 57-ve.

HLA-associated non-responsiveness to hepatitis B vaccine

HLA-A,B,DR antigens of two groups, one of normal individuals (N- = 31) and another of CRF (Chronic Renal Failure) patients (K- = 37), who did not develop anti-HBs protective antibodies after Hepatitis B (HB) vaccination, were compared, respectively, to the HLA antigens of two corresponding control groups (N+ = 52, K+ = 49), who responded to the vaccine. A statistically significant difference (Pc less than 0.02) in the frequency of HLA-DR3 was observed between responders and non-responders. An increased frequency of HLA-A1 and HLA-B8 in N- as well as of HLA-A1 and HLA-B35 in K- was also noticed, but this was not of statistical significance. As these antigens have been associated to both HBs antigenemia as well as chronic active hepatitis, we suggest that these genes or other genes in linkage to those may suppress the response to HBV vaccination while, in parallel, they may predispose to an autoimmune course of Hepatitis.

The significance of a persistent precordial ST segment greater than or equal to 0.1 mV depression in acute inferior myocardial infarction (coronary angiographic and ventriculographic findings)

40 patients with acute inferior myocardial infarction (MI) associated with persistent precordial ST segment depression greater than or equal to 0.1 mV underwent coronary arteriography and left ventriculography within 5-6 days of their admission. The inferior MI was the result of complete occlusion of the right coronary artery (RCA) in 38 patients and the result of complete occlusion of the posterior descending artery (PDA) coming off the circumflex artery (Cx) in two patients. 36 (90%) of the 40 patients showed one or more severe stenoses in the left anterior descending artery (LAD). 12 of the 36 patients had severe triple vessel disease. The 36 patients whose coronary arteriograms showed significant LAD stenosis had an emergency coronary artery by pass graft (CABG) operation. Soon afterwards the precordial leads were normal and the patients free of angina till their discharge from hospital. We conclude that a persistent precordial ST segment greater than or equal to 0.1 mV depression in acute inferior MI is highly predictive of significant LAD disease.

Inhospital prognosis of patients with their first transmural or subendocardial infarction and comparison of their coronary arteriogram and ventriculogram

The inhospital clinical course and early prognosis were studied prospectively in 500 patients who suffered their first transmural or subendocardial myocardial infarction, and were admitted in the coronary care unit of our hospital over the last four years. The coronary arteriogram and left ventriculogram of 300 patients out of the 500 was also compared. 434 patients developed transmural and 66 subendocardial infarction, as judged by electrocardiographic criteria. Both groups of patients had the same range of sex, age, coronary risk factors and history of previous angina. There was no statistical difference in in-hospital prognosis and early clinical course. There was no difference in prevalence of single, double or triple vessel coronary artery disease. The hemodynamic parameters (ejection fraction, left ventricular end-diastolic pressure), as well as the number of hypokinetic, akinetic or dyskinetic segments did not show any significant statistical difference between the two categories of patients. The same extent of coronary artery lesions and degree of left ventricular dysfunction may explain the similarity of early clinical course. 12% of patients who were admitted with subendocardial infarction developed transmural infarction during their hospitalization.