[GIP-like findings with a special spectrum of causes]. / GIP-ähnliche Befunde mit besonderem Ursachenspektrum.

Giant cell interstitial pneumonia (GIP)-like pulmonary alterations as a special form of condensate pneumopathy may result following inhalation of certain types of tobacco smoke which can cause a pitfall diagnosis of sideropneumoconiosis or hard metal lung disease. Exact information regarding the patient occupation and smoking history and especially regarding the origin of the cigarettes helps to clarify the findings.

[Evaluation of a new automatic CPAP algorithm in the treatment of obstructive sleep apnoea syndrome]. / Evaluation eines neuen Algorithmus zur automatischen CPAP-Therapie beim obstruktiven Schlafapnoe-Syndrom.

BACKGROUND: Automatic continuous positive airway pressure (automatic CPAP, APAP) is an effective treatment option in the obstructive sleep apnoea syndrome (OSAS). The differentiation of obstructive and central respiratory events is crucial in adjusting the optimal pressure in this treatment mode. In this pilot study we evaluated a new automatic CPAP algorithm in OSAS patients. METHODS: 14 patients with newly diagnosed obstructive sleep apnoea syndrome were enrolled. After a diagnostic polysomnography, patients were treated for one night with a new APAP device based on flow, snoring, relative minute volume and the obstructive pressure peak signal. RESULTS: The total apnoea/hypopnoea index (AHI) was 30.0 +/- 21.4/h at baseline and 3.7 +/- 5.3/h with APAP ( P < 0.005). Both obstructive AHI (22.7 +/- 20.5/h at baseline, 1.5 +/- 3.5/h with APAP, P < 0.005) and central AHI (7.3 +/- 4.9/h and 2.2 +/- 2.5/h, respectively, P < 0.01) as well as the arousal index (25.4 +/- 18.1/h and 5.1 +/- 3.8/h, respectively, P < 0.005) were reduced significantly with the new algorithm. CONCLUSIONS: The new algorithm of an automatic CPAP device is effective in the treatment of obstructive sleep apnoea syndrome.

The repopulation capacity of bone marrow grafts following pretreatment with monoclonal antibodies against T lymphocytes in rhesus monkeys.

Complement-mediated lysis of (subsets of) T lymphocytes in bone marrow grafts is increasingly used to prevent acute graft-versus-host disease in human bone marrow transplant recipients, especially in case of major immunogenetic disparity between donor and recipient. Since T lymphocyte depletion has resulted in an increased frequency of allogeneic engraftment failures, its effect on hemopoietic reconstitution was measured in rhesus monkeys. The reactivity patterns of commonly used types of antihuman T lymphocyte monoclonal antibodies (MCAs) with rhesus monkey lymphocytes was analyzed using a double-label cytofluorometry technique and found to be very similar to those with human lymphocytes. The antibodies investigated included CAMPATH-1 (recognizing an antigen present on virtually all lymphocytes and monocytes), OKT4 + 4a (CD4, helper/inducer T lymphocytes), B9 (CD8, suppressor/cytotoxic T lymphocytes), WT-1 (CD7, pan-T), and anti-DR MCAs as stem cell toxic controls. Their possible toxicity to hemopoietic stem cells was studied by using a semiquantitative autologous regeneration assay. Cytotoxic lysis of cells in the bone marrow grafts reacting with the T lymphocyte purging MCAs did not result in delayed regeneration compared to untreated autologous grafts. It is concluded that T lymphocyte depletion using anti-T-lymphocyte MCAs does not influence the repopulating capacity of an autologous bone marrow graft.

Mhc-DRB and -DQA1 nucleotide sequences of three lowland gorillas. Implications for the evolution of primate Mhc class II haplotypes.

Mhc-DRB and -DQA1 second-exon and -DRB 3'-untranslated-region nucleotide sequences of three lowland gorillas with no known family relationship with each other and of two HLA homozygous typing cell lines were determined and compared with published primate Mhc-DRB and -DQA1 sequences. Eleven distinct MhcGogo-DRB second-exon sequences were found, which represent the gorilla counterparts of the HLA-DRB1*03, -DRB1*10, -DRB3, -DRB5, and -DRB6 allelic lineages. One Gogo-DRB second-exon sequence does not have an obvious human counterpart and is tentatively designated Gogo-DRBY*01. The gorilla equivalents of the HLA-DRB2 and -DRB8 loci were identified as judged on Mhc-DRB 3'-untranslated-region sequences. In addition, four different Gogo-DQA1 alleles belonging to three different allelic lineages were detected. The Mhc-DRB-DQA1 haplotypes of these gorillas were deduced based on the obtained Mhc-DRB and -DQA1 sequences and the two published Mhc-DRB haplotypes of the lowland gorilla Sylvia. All deduced Gogo-DRB-DQA1 haplotypes show gene constellations different from known HLA-DRB-DQA1 haplotypes, while some of the Gogo-DRB haplotypes presented here contain more DRB genes than the HLA-DRB haplotypes. Based on phylogenetic trees, bootstrap analyses, and the gorilla, chimpanzee, and human Mhc-DRB haplotypes described, we propose that at least two Mhc-DRB loci, here tentatively designated Mhc-DRBI and -DRBII, existed on an ancient primate Mhc-DRB haplotype. The Mhc-DRB1*01, -DRB1*02 (-DRB1*15 and -DRB1*16), -DRB1*03 (-DRB1*03, -DRB1*08, -DRB1*11, -DRB1*12, -DRB1*13, and DRB1*14), and -DRB1*10 allelic lineages and -DRB3 and -DRBY loci probably evolved from the hypothetical primate Mhc-DRBI locus, whereas the present primate Mhc-DRB2, -DRB4, and -DRB6 loci originate from the ancient Mhc-DRBII locus of this core primate Mhc-DRB haplotype.

Unambiguous typing for HLA-DQ TA10 and 2B3 specificities using specific oligonucleotide probes.

Oligonucleotide probes specific for the serologically defined TA10 and 2B3 specificities were selected based on a comparison of the available HLA-DQ beta sequences. Panel and family segregation studies confirm a complete correlation between the reactivities of the selected probes and the TA10/IIB3 antibodies. The Glu residue at position 45 of the HLA-DQ beta chain is specific for the TA10 determinants, and a DQ beta Gly-Val-Tyr sequence is found at position 45-47 for all 2B3-positive DQ beta chains.

Morbillivirus infections of aquatic mammals: newly identified members of the genus.

Several disease outbreaks, which have caused the deaths of many thousands of seals and dolphins during the last decade, have now been attributed to infections with newly identified Morbilliviruses. Outbreaks in the late eighties amongst harbour seals (Phoca vitulina) and grey seals (Halichoerus grypus) in northwestern Europe and amongst baikal seals (Phoca sibirica) in Siberia were caused by the newly discovered phocine distemper virus and by a strain of canine distemper virus, respectively. Although closely related these two viruses were not identical. They were more distantly related to the viruses which caused mass mortality amongst striped dolphins (Stenella coeruleoalba) in the Mediterranean sea in the early nineties. This dolphin morbillivirus was shown to be closely related to a virus that was found in harbour porpoises (Phocoena phocoena) which had stranded at the coasts of northwestern Europe in the late eighties: porpoise morbillivirus. The present knowledge of the genetic and antigenic relationships of these apparently new members of the genus Morbillivirus with the established members of the genus is presented. In addition, the origin and epizootiological aspects of these newly discovered viruses are discussed. Finally experimental evidence that environmental pollution may have contributed to the severity and extent of these infections in recent years is presented.

[Time for professionalising the system of medical ethics review in the Netherlands]. / Tijd voor professionalisering van het systeem van medisch-ethische toetsing in Nederland.

In two recent papers, a radical change of the review system for medical ethics review committees was proposed. The current systems in Great Britain and Australia were described and it was suggested that the extended roles and responsibilities of the medical ethics review committees could not be fulfilled by the present committees. It was proposed that professional medical ethics committees be established with full time members who would receive an appropriate honorarium. The Netherlands has a decentralised system of medical ethics review, which is based on peer review. A radical change of the current system of medical ethics review is not warranted. There is however a need for further improvements to the current peer-review system. An important aspect of this improvement is an honorarium for the members as well as a budget for training and for the adequate scientific and administrative support of the committee by a secretariat. The fees levied for reviewing each protocol could in part finance the committee and its secretariat. However, these fees will probably not meet all of the costs. Therefore the centres involved in medical research should consider supporting their committees. It is in their interest to demonstrate their wish to protect those persons who consent to participate as research subjects. This will maintain the confidence of both the public and future participants in clinical trials. Furthermore, an efficient and adequate system of ethical review will support a balanced view towards medical research with human subjects and will also contribute to a positive image of the centre also as an attractive environment for medical professionals.

Legislation and review of medical research with minors in The Netherlands.

In The Netherlands medical research with minors is regulated in the Medical Research Involving Human Subjects Act. During the legislation process in the Houses of Parliament in the 1990s the issue of nontherapeutic research with minors and incapacitated subjects was heavily debated. Stringent regulations were formulated for this type of research and the Act became operational in December 1999. In order to implement the Clinical Trial Directive 2001/20/EG, the Act was modified on several issues. However, the Act was not modified on the issue of non-therapeutic research with minors and incapacitated subjects. As a result at present the Dutch law is more restrictive on non-therapeutic research with minors than the EU Directive. Currently, discussion is ongoing to adapt the Dutch law in order to harmonize it with the EU Directive.

Major histocompatibility complex class II polymorphisms in humans and chimpanzees.

Allelic variation at the MhcPatr-DR and -DQ loci was studied by molecular biological techniques and compared to available HLA data. With regard to the number of allelic lineages, the chimpanzee shows a condensation of its major histocompatibility complex (MHC) class II repertoire as compared to humans. This does not have an impact on the overall degree of MHC class II polymorphism in the chimpanzee since a few lineages that are oligomorphic in humans display an extensive degree of polymorphism in the chimpanzee.

Comparative analysis of the gene encoding the nucleocapsid protein of dolphin morbillivirus reveals its distant evolutionary relationship to measles virus and ruminant morbilliviruses.

A morbillivirus of uncertain origin recently killed hundreds of Mediterranean dolphins. This is the first report of the nucleotide and deduced amino acid sequence of a dolphin morbillivirus (DMV) gene. The sequence of the nucleocapsid (N) gene including boundaries was determined. When the DMV N gene coding region was compared with the corresponding sequences of other morbilliviruses a distant evolutionary relationship between these viruses and DMV was apparent. Phylogenetic analysis of the sequence data provided further evidence that DMV is not closely related to any known morbillivirus, whereas phocine distemper virus exhibits a relatively close relationship to canine distemper virus.

Allelic diversity at the Mhc-DP locus in rhesus macaques (Macaca mulatta).

Allelic diversity at the major histocompatibility complex class II DP locus of rhesus macaques was studied by sequencing exon 2 of Mamu-DPA1 and -DPB1 genes. The Mamu-DPA1 gene is apparently invariant, whereas the Mamu-DPB1 locus displays polymorphism. Here we report the characterization of 1 Mamu-DPA1 and 13 Mamu-DPB1 alleles which were compared with other available primate Mhc-DPA1 and -DPB1 sequences. As compared with Mhc-DRB and -DQB1, most codons for the contact residues in the antigen binding site of the primate Mhc-DPB1 gene have a relatively low degree of variation in encoding various types of amino acids. In contrast to Mhc-DRB and -DQB, the HLA- and Mamu-DPB1 sequences cluster in a species-specific manner in phylogenetic trees. Mhc-DPB1 polymorphisms, however, are inherited in a transspecies mode of evolution, as is demonstrated by the sharing of lineage members between closely related macaque species. The data demonstrate that the transspecies character of Mhc-DPB1 polymorphism was retained over much shorter periods of time as compared with its sister class II loci, Mhc-DQ and -DR.

Insertion of N-linked glycosylation sites in the variable regions of the human immunodeficiency virus type 1 surface glycoprotein through AAT triplet reiteration.

Variable regions with sequence length variation in the human immunodeficiency virus type 1 envelope exhibit an unusual pattern of codon usage with AAT, ACT, and AGT together composing > 70% of all codons used. We postulate that this distribution is caused by insertion of AAT triplets followed by point mutations and selection. Accumulation of the encoded amino acids (asparagine, serine, and threonine) leads to the creation of new N-linked glycosylation sites, which helps the virus to escape from the immune pressure exerted by virus-neutralizing antibodies.

Mhc-DRB diversity of the chimpanzee (Pan troglodytes).

Fifty-four chimpanzee Patr-DRB and five human HLA-DRB second exons were cloned and sequenced from thirty-five chimpanzees and four human B-cell lines and compared with known Mhc-DRB sequences of these two species. Equivalents of the HLA-DRB1*02, -DRB1*03, -DRB1*07 allelic lineages and the HLA-DRB3, -DRB4, -DRB5, -DRB6, and -DRB7 loci were all found in the chimpanzee. In addition, two chimpanzee Patr-DRB lineages (Patr-DRBX and -DRBY) were found for which no human counterparts have been described. None of the Patr-DRB sequences is identical to known HLA-DRB sequences. The Patr-DRB1*0702 and HLA-DRB1*0701 alleles are the most similar sequences in a comparison between the two species and differ by only two nucleotides out of 246 sequenced. Equivalents of the HLA-DRB1*01, -DRB1*04, and -DRB1*09 alleles were not found in our sample of chimpanzees. A per locus comparison of the number of Patr-DRB alleles with the HLA-DRB alleles shows that the Patr-DRB3, -DRB4, -DRB5, and -DRB6 locus are, thus far, more polymorphic than their human homologs. The polymorphism of the Patr-DRB1 locus seems to be less extensive than that reported for the HLA-DRB1 locus. Nevertheless, the Patr-DRB1 locus seems to be the most polymorphic of the Patr-DRB loci. Phylogenetic analyses indicate that the HLA-DRB1*09 allele may have originated from a recombination between a Mhc-DRB5 allele and the DRB1 allele of a Mhc-DR7 haplotype. Although recombination seems to increase the diversity of the Patr-DRB alleles, its contribution to the generation of Patr-DRB variation is probably low. Hence, most Patr-DRB diversity presumably accumulated via recurrent point mutations. Finally, two distinct Patr-DRB haplotypes are deduced, one of which (the chimpanzee equivalent of the HLA-DR7 haplotype) is probably older than 6-8 million years.

A personal computer program for large-scale comparisons of related nucleotide sequences.

A personal computer program (COMPSEQ) has been developed which can present an informative listing of pre-aligned exonic nucleotide sequences and of their translations to amino acid sequences as well run triplet-oriented analyses on these sequences in a given reading frame. The sequence listing focuses on the differences between related sequences by suppressing the concordances between them.

Mhc-DQB repertoire variation in hominoid and Old World primate species.

Comparison of 87 distinct Mhc-DQB sequences, obtained from 13 primate species, demonstrates that five out of eight trans-species Mhc-DQB allele lineages are at least 30 million years old and predate divergence of hominoid and Old World primate species. One lineage may be much older because its members are not only traced back in higher primates, but also are present in a New World primate species. Comparing Mhc-DQB repertoire variation in distinct species, allows one to pinpoint when certain polymorphisms were lost or gained in primate evolution. Heterogeneity observed among members of trans-species Mhc-DQB allele lineages can be explained in major part by point mutations, whereas intraexonic crossing-over is a potent mechanism in generating new allele lineages. The stability of Mhc-DQB polymorphisms is influenced by selective forces because distinct allele lineages appear to have accumulated nucleotide substitutions and amino acid replacements at different rates.

Evolutionary relationships among the primate Mhc-DQA1 and DQA2 alleles.

The variation of the Mhc-DQA1 and DQA2 loci of ten different primate species (hominoids and Old World monkeys) was studied in order to obtain an insight in the processes that generate polymorphism of major histocompatibility complex (Mhc) class II genes and to establish the evolutionary relationships of their alleles. To that end nucleotide sequences of 36 Mhc class II DQA1 and seven DQA2 second exons were determined and phylogenetic trees that illustrate their evolutionary relationships were constructed. We demonstrate the existence of four primate Mhc-DQA1 allele lineages, two of which probably existed before the separation of the ancestors of the hominoids and Old World monkeys (approximately 22-28 million years ago). Mhc-DQA2 sequences were found only in the hominoid species and showed little diversity. We found no evidence for a major contribution of recombinational events to the generation of allelic diversity of the primate Mhc-DQA1 locus. Instead, our data suggest that the primate Mhc-DQA1 and DQA2 loci are relatively stable entities that mutated primarily as a result of point mutations.

Diversity of immunoglobulin heavy chain gene segment rearrangement in B lymphoblastoid cell lines from X-linked agammaglobulinemia patients.

X-linked agammaglobulinemia (XLA) is characterized by an arrest in early B lymphocyte differentiation. Precursor B cells are present in the bone marrow (BM), whereas peripheral blood B cell numbers are severely decreased. A series of Epstein-Barr virus (EBV)-transformed B lymphoblastoid cell lines (BLCL) was established from peripheral blood of three XLA patients belonging to one pedigree. These BLCL manifested productive VHDJH rearrangements and a random utilization of the VH families. The CDR3 regions of the rearrangements varied in length from 12 to 47 nucleotides and included N regions in all cases. The results supported the conclusion that the few B lymphocytes in peripheral blood of XLA patients exhibit all mechanisms that generate immunoglobulin (Ig) heavy (H) chain diversity. However, no evidence for somatic mutation was found. Within the VH3 family 50% of the expressed VH gene segments belonged to a single subgroup and within the VH4 family a preferential utilization of one VH4 gene element was observed. The utilization of H chain joining (HH) elements was biased to JH4 and JH6 and a high percentage of the CDR3 regions was found to be generated by unconventional mechanisms, such as multiple D usage and the fusion of D elements to D segments with irregular recombination recognition signals. These unique features of the recombined and expressed VHDJH regions in XLA may explain the inability of XLA patients to respond to a variety of antigens. Alternatively, they could be secondary to a B lymphocyte maturation defect in XLA.