Nuclear EGFR characterize still controlled proliferation retained in better differentiated clear cell RCC

Renal cell carcinoma (RCC) is the most common solid kidney tumor representing 2-3% of all cancers, with the highest frequency occurring in Western countries. There was a worldwide and European annual increase in incidence of approximately 2% although incidence has been stabilized in last few years. One third of the patients already have metastases in the time of the diagnosis with poor prognosis because RCC are radio and chemoresistant. The prognostic value of EGFR over-expression in RCC is a controversial issue that could be explained by different histological types of study tumors and non-standardized criteria for evaluation of expression. Recent evidences points to a new mode of EGFR signaling pathway in which activated EGFR undergoes nuclear translocalization and then, as transcription factor, mediates gene expression and other cellular events required for highly proliferating activities. According to our observations, the membranous expression of EGFR associates with high nuclear grade and poor differentiated tumors. On the other hand, nuclear EGFR expression was high in low nuclear graded and well differentiated tumors with good prognosis. We hypothesize that this mode of EGFR signaling characterizes still controlled proliferation retained in well differentiated RCC with Furhman nuclear grade I or II.

EGFR expression is linked to osteopontin and Nf-κB signaling in clear cell renal cell carcinoma

AIM AND BACKGROUND

Epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase involved in many important aspects of cell biology that are related to tumorigenesis. There are opposite evidences of the role of EGFR in renal cancer and the outcome of EGFR-targeted therapies, suggesting the complexity of EGFR signaling pathways. In vitro, osteopontin (OPN) and nuclear factor kappa B (NF-κB) are thought to be involved in specific ligand-independent EGFR activation that could have a role in resistance to EGFR mAb therapy. Aim of this study was to analyze the relationship between EGFR and OPN at the protein and mRNA level, as well as their relation to NF-κB in clear cell renal cell carcinoma (CCRCC).

MATERIALS AND METHODS

Expression of EGFR, OPN, and p65 NF-κB protein was analyzed using immunohistochemistry and compared mutually in 88 CCRCC samples. Expression of EGFR and OPN mRNAs was analyzed using quantitative Real-time PCR in 22 CCRCC samples and compared mutually and with NF-κB protein expression.

RESULTS

Epidermal growth factor receptor mRNA level was higher in CCRCC samples in comparison with normal renal tissue (p = 0.012) and was associated with high OPN mRNA level, and with NF-κB activation (p < 0.001 and p = 0.045, respectively). Immunohistochemical staining showed the inverse association; high EGFR protein expression was related with low OPN and NF-κB protein expression (p < 0.001 and p = 0.047, respectively).

CONCLUSION

Epidermal growth factor receptor gene is upregulated in CRCC and associated with OPN gene expression and NF-kB signaling. The inverse relation between OPN and EGFR at the protein level could probably reflect dynamic changes that EGFR undergoes following activation.

Mitochondrial DNA heritage of Cres Islanders--example of Croatian genetic outliers

Diversity of mitochondrial DNA (mtDNA) lineages of the Island of Cres was determined by high-resolution phylogenetic analysis on a sample of 119 adult unrelated individuals from eight settlements. The composition of mtDNA pool of this Island population is in contrast with other Croatian and European populations. The analysis revealed the highest frequency of haplogroup U (29.4%) with the predominance of one single lineage of subhaplogroup U2e (20.2%). Haplogroup H is the second most prevalent one with only 27.7%. Other very interesting features of contemporary Island population are extremely low frequency of haplogroup J (only 0.84%), and much higher frequency of haplogroup W (12.6%) comparing to other Croatian and European populations. Especially interesting finding is a strikingly higher frequency of haplogroup N1a (9.24%) presented with African/south Asian branch almost absent in Europeans, while its European sister-branch, proved to be highly prevalent among Neolithic farmers, is present in contemporary Europeans with only 0.2%. Haplotype analysis revealed that only five mtDNA lineages account for almost 50% of maternal genetic heritage of this island and they present supposed founder lineages. All presented findings confirm that genetic drift, especially founder effect, has played significant role in shaping genetic composition of the isolated population of the Island of Cres. Due to presented data contemporary population of Cres Island can be considered as genetic "outlier" among Croatian populations.

HPV testing for cervical cancer screening in Croatia

Opportunistic screening based on the Pap smear has been undertaken in Croatia since 1953. However, cervical cancer remains an important health problem in Croatia when compared to European countries with organised screening programmes. In Croatia, in addition to screening based on well established cytology, Human papillomavirus (HPV) testing is widely used as secondary test as a triage to borderline cytology and as a follow-up after treatment of severe cervical lesions. Many different approaches for HPV testing arose in Croatia over the last decade depending on the needs of each medical institution involved. Presently, there is an urgent need for better networking between the laboratories, the implementation of quality assessment and the adaptation of a uniform system of referring to and reporting of HPV testing. In conclusion, the best possible organisation for HPV testing would be essential for implementation of HPV testing as primary screening test in Croatia, an thus ultimately and hopefully, the more successful cervical cancer control.

Severe neonatal neutropenia due to anti-human leucocyte antigen B49 alloimmunization only: a case report

Alloimmune neonatal neutropenia (ANN) is a rare but potentially life-threatening disorder of neonates. Demonstration of alloantibodies against granulocyte-specific antigens shared by neonatal and paternal granulocytes in the maternal serum is essential in the diagnosis of ANN. In contrast to granulocyte-specific alloantibodies, the significance of human leucocyte antigen (HLA) class I antibodies for ANN is still a matter of debate. We report on a case of severe isolated and prolonged neutropenia due to anti-HLA B49 alloimmunization only. Immediately after birth, severe, isolated neutropenia was observed and lasted for up to 2 months. Results of serologic testing showed only anti-HLA B49 antibodies in the maternal and neonate's sera. HLA typing showed HLA class I (B49) incompatibility between the mother and the child. Granulocyte-specific antibodies were not detected. Adsorption of the maternal serum with HLA B49-bearing platelets removed serum reactivity with paternal neutrophils. Our results support the idea that certain HLA class I antibodies can induce ANN.

RT-PCR detection of tyrosinase, gp100, MART1/Melan-A, and TRP-2 gene transcripts in peripheral blood of melanoma patients

AIM

To detect the expression of genes encoding tyrosinase, gp100, MART-1/Melan A, and tyrosinase-related protein-2 (TRP-2) in peripheral blood of melanoma patients by reverse transcription-polymerase chain reaction (RT-PCR).

METHODS

Nineteen peripheral blood samples were obtained from 17 melanoma patients. When tested, 15 of them presented with clinically detectable metastatic disease. Samples of peripheral blood (7 mL) were collected from each patient into vacutainer cell preparation tubes. Mononuclear cells were isolated, total cellular RNA extracted, and then used as a template for reverse transcription to complementary DNA (cDNA). The cDNA was thereafter assayed by PCR for the expression of melanocyte-associated transcripts of tyrosinase, gp100, MART1/Melan-A, and TRP-2 genes.

RESULTS

Gp100 gene expression was detected in 13 out of 19 samples. In 4 of them, TRP-2 gene expression was also detectable. Expression of tyrosinase and Melan-A/MART-1 genes could not be observed. Interestingly, gp100 and TRP-2 gene transcripts were detected in patients having recurrent and/or metastatic disease at the time of testing.

CONCLUSION

The results we obtained support the use of RT-PCR assay for indirect detection of melanoma cells in peripheral blood of melanoma patients. As the transcripts for the tyrosinase gene and MART-1/Melan A gene were not detected, additional optimization experiments of RT-PCR assay are required.

[Neonatal alloimmune thrombocytopenic purpura caused by anti-HPA-1a alloantibodies. Case report]

We report the case of serologically proven HPA-1a NATP. The child was born after uneventful 4th pregnancy. Immediately after birth generalized petechiae and signs of gastrointestinal bleeding were present. Isolated thrombocytopenia with the platelet number of 29 x 10(9)/L was observed. Serological investigation (PSIFT and MAIPA) showed high titre anti-HPA-1a antibody and low titre anti-HLA antibody in mother's sera. Mother's platelets were HPA-1a negative and she was HLA DR 52 positive. Father's platelets were HPA-1a positive. Cross-match between mother's sera and father's platelets was positive. 24 hours after the introduction of corticosteroid therapy platelet number increased to 73 x 10(9)/L and 48 hours later to 155 x 10(9)/L. The child was treated by corticosteroids because the NATP was severe and antigen negative platelets (mother or donor) or IVGG were not available. According to data from the literature the efficiency of corticosteroid therapy in NATP is questionable, but in this case it provided sufficient increase of platelet number with the stop of newborn bleeding.

Dynamics of serum hepatitis C virus load and quasispecies complexity during antiviral therapy in patients with chronic hepatitis C

BACKGROUND

Hepatitis C virus (HCV) infection is a dynamic process during which viral genetic variants continuously develop as a result of the virus adaptation to the host's immune system. The level of viremia and the complexity of the hypervariable region 1 (HVR 1) quasispecies of hepatitis C virus during antiviral therapy reflect the dynamic balance between the viral and host components in response to therapy.

OBJECTIVE

The aim of the study was to evaluate the dynamics of HCV viremia and the complexity of the HVR 1 quasispecies during the induction phase of a triple combination therapy regimen in nonresponders to earlier anti-HCV treatment.

STUDY DESIGN

Ten patients with chronic hepatitis C undergoing antiviral combination therapy with interferon-alpha, ribavirin, and amantadine were studied. The serum HCV RNA level was monitored by a quantitative RT-PCR assay up to 3 months after start of treatment. The HVR 1 quasispecies complexity was analysed by an "in house" nested RT-PCR mediated single-strand conformation polymorphism (SSCP) assay.

RESULTS

Baseline serum HCV RNA levels ranged from 1.94x10(6) to 5.53x10(6) copies/ml. In all patients, HCV subtype 1b was found. At the start of therapy, the SSCP assay revealed a high complexity pattern (at least six SSCP bands) in all patients. None of the patients responded within 4 weeks of treatment, however, the serum HCV RNA level decreased by one to two logs in eight patients. At week 4 after start of treatment, there was a decrease of SSCP bands in five patients. In four patients, SSCP bands remained unchanged and in one patient SSCP bands increased. At month 3 after start of treatment, serum HCV RNA was not detectable in one patient.

CONCLUSION

Because of the low number of patients involved in this study, prediction of therapeutical success based on the quasispecies complexity was not possible. Larger studies are urgently needed.

Hypervariable region 1 of hepatitis C virus genome and response to interferon therapy

The relationship between the complexity of the hypervariable region 1 (HVR1) quasispecies of hepatitis C virus (HCV) and responsiveness to interferon-alpha (IFN) therapy was studied in patients with chronic hepatitis C. Twelve HCV-RNA-positive patients were treated daily with high dose IFN and ribavirin for 4 weeks, and then with IFN 3 MIU (Million International Units) TIW (three times per week) and ribavirin for 6 months. The HVR1 quasispecies complexity was analyzed by nested polymerase chain reaction-mediated single-strand conformation polymorphism (SSCP). The baseline HCV-RNA levels in the study group ranged from 10(6) to 10(7) copies/ml. All patients exhibited HCV genotype 1 b. Initial SSCP analysis revealed four (33.3%) patients with a low complexity pattern (SSCP bands < or =4) and eight (66.6%) patients with high complexity pattern (SSCP bands >4). After 4 weeks of IFN therapy, one patient became HCV negative, and among those remaining positive, the HCV-RNA levels decreased by 2 to 3 logs and the number of SSCP decreased by 2 to 3 bands per sample. After 6 months of IFN therapy, five (41.7%) patients became HCV-RNA-negative. Seven (58.3%) patients did not respond to IFN therapy with sustained viral load from 10(3) to 10(5) copies/ml, and high complexity SSCP patterns. Our data support the HVR quasispecies complexity to be an independent predictive factor for IFN responsiveness in patients infected with HCV.

Detection and genotyping of Borrelia burgdorferi sensu lato by polymerase chain reaction

AIM

To isolate and genotype Borrelia burgdorferi genospecies in serum samples of Croatian patients with erythema migrans.

METHODS

DNA isolates from sera of patients with erythema migrans were analyzed by nested polymerase chain reaction (PCR), amplifying a segment of flagellin gene with primers encompassing the conserved region of the gene. To screen PCR products for heterogeneity, we performed single-stranded conformation polymorphism (SSCP) analysis. The samples showing differences in SSCP patterns were sequenced, and the sequence compared in the GeneBank for sequence homology with known Borrelia burgdorferi genospecies. We also constructed phylogenetic tree of all known borrelial sequences.

RESULTS

The nested PCR method using specially designed flagellin gene primers, achieved the sensitivity of 10 genome copies (0.01 pg of purified Borrelia burgdorferi DNA from culture) by dilution analysis. The assay specificity was confirmed by amplification of a part of the flagellin gene from different bacterial species. The primer pairs successfully amplified only Borrelia burgdorferi flagellin gene. The genome of Borrelia burgdorferi sensu lato was detected in the sera of all 10 tested patients with erythema migrans. Sequence data and phylogenetic analysis confirmed that all amplified samples belonged to Borrelia afzelii genospecies.

CONCLUSION

Phylogenetic tree analysis placed the borrelial isolates together with Borrelia afzelii sequences into a single group. This finding was additionally supported by sequence homology analysis, which produced a homology score of 99%. In patients with erythema migrans who come from the northwest Croatia, an endemic area for Lyme borreliosis, Borrelia afzelii was the cause of skin manifestations of Lyme borreliosis.

Polymorphism of the HLA class II loci in Siberian populations

The populations that colonized Siberia diverged from one another in the Paleolithic and evolved in isolation until today. These populations are therefore a rich source of information about the conditions under which the initial divergence of modern humans occurred. In the present study we used the HLA system, first, to investigate the evolution of the human major histocompatibility complex (MHC) itself, and second, to reveal the relationships among Siberian populations. We determined allelic frequencies at five HLA class II loci (DRB1, DQA1, DQB1, DPA1, and DPB1) in seven Siberian populations (Ket, Evenk, Koryak, Chukchi, Nivkh, Udege, and Siberian Eskimo) by the combination of single-stranded conformational polymorphism and DNA sequencing analysis. We then used the gene frequency data to deduce the HLA class II haplotypes and their frequencies. Despite high polymorphism at four of the five loci, no new alleles could be detected. This finding is consistent with a conserved evolution of human class II MHC genes. We found a high number of HLA class II haplotypes in Siberian populations. More haplotypes have been found in Siberia than in any other population. Some of the haplotypes are shared with non-Siberian populations, but most of them are new, and some represent "forbidden" combinations of DQA1 and DQB1 alleles. We suggest that a set of "public" haplotypes was brought to Siberia with the colonizers but that most of the new haplotypes were generated in Siberia by recombination and are part of a haplotype pool that is turning over rapidly. The allelic frequencies at the DRB1 locus divide the Siberian populations into eastern and central Siberian branches; only the former shows a clear genealogical relationship to Amerinds.

War injuries of the kidney

Between 2 May 1991 and 2 November 1992, 4425 wounded people were treated at the Clinical Hospital of Osijek, Croatia. A hundred and fifteen (2.6 per cent) had a urogenital injury, 64 (56 per cent) of whom had penetrating kidney injuries. Sixteen (25 per cent) of this 64 were caused by gunshot wounds and 48 (75 per cent) by fragments of mines, mortars or grenades. The majority of the 64 kidney injuries had also associated injuries of some other major organ system, particularly in the abdomen, with only three cases of isolated kidney injury. In 53 patients (82.8 per cent) surgical access was by transabdominal incision, in nine (14 per cent) by extraperitoneal flank incision and in two cases thoracophrenolaparotomy was also performed. Nephrectomy was performed in 16 patients (25 per cent). In 46 (75 per cent) an organ-sparing procedure was done: kidney sutures in 28 (43.8 per cent), kidney resection in five (7.8 per cent) and exploration only in 15 (23.4 per cent). Intrahospital deaths occurred in 11 (18 per cent), seven in the operating theatre. An evaluation of the 6-month follow up for 90 per cent of the surviving patients is presented. It seems that the frequency of renal war injuries was lower than usually reported. Associated abdominal injuries justified surgical access by transabdominal incision. The high mortality rate is explained by a large number of associated injuries and by the proximity of the battlefield with resulting rapid transport of patients (average 52 min), which excluded the possibility of separating out the moribund patients. Long-term follow up confirmed the benefits of the conserving surgical approach.

Molecular monitoring of minimal residual disease in acute promyelocytic leukemia by the polymerase chain reaction assay for the PML/RAR alpha (retinoic acid receptor-alpha) fusion transcript in patients treated with all-trans retinoic acid followed by chemotherapy

Five acute promyelocytic leukemia (APL) patients who achieved a complete remission (CR) with all-trans retinoic acid (ATRA) underwent residual disease monitoring through reverse transcription polymerase chain reaction (PCR) for PML/retinoic acid receptor-alpha (PML/RAR alpha) fusion transcript. All received consolidation chemotherapy in CR, one in the form of autologous bone marrow transplantation (ABMT). In four of the patients PCR was positive for the PML/RAR alpha transcript immediately after ATRA treatment and/or after the first consolidation chemotherapy course. In the patient treated with ABMT, positivity was still detected six months after ABMT. One patient given five repeated courses of chemotherapy was PCR negative for PML/RAR alpha after 14 months in CR. Our pilot study confirmed that ATRA is a highly efficient induction therapy for APL in various stages of the disease, but ATRA alone cannot cure the disease. PCR should be considered a fundamental assay for assessing minimal residual disease in CR that will influence further treatment strategies and permit evaluation of treatment results.

Allele-specific peptide ligand motifs of HLA-C molecules

The consensus motifs of HLA-Cw3, -Cw4, -Cw6, and -Cw7 ligands were determined by pool sequencing. Together with information obtained by sequencing of some prominent individual peptides, the results indicate the following: (i) all four HLA-C molecules are associated with peptides. (ii) These peptides adhere to allele-specific motifs that are similar to those of to HLA-A or -B molecules; they have a preferred length of nine amino acids and an anchor residue at the C terminus. (iii) All four HLA-C molecules analyzed exhibit related peptide motifs, although each allelic product shows individual characteristics in fine specificity. (iv) Processing and origin of peptides appear not to be different from that of other class I molecules. (v) No obvious difference at C-terminal position 9 was present in the peptides isolated from the two dimorphic variants of HLA-C that determine dominant resistance to natural killer NK1-specific cells (HLA-Cw4, -Cw6) or to NK2-specific cells (HLA-Cw3, -Cw7) and that differ in two residues in or near the pocket at position 9.

Conservative evolution of the Mbc-DP region in anthropoid primates

To determine the organization of the DP region in the Mbc of anthropoid primates, we constructed contig maps from cosmid clones of the chimpanzee and orangutan, representatives of the infraorder Catarrhini, as well as of the cotton-top tamarin, a representative of the infraorder Platyrrhini. We found the maps to be remarkably similar to each other and to the previously published map of the human DP region. In each of the four species, the DP region consists of four loci arranged in the same order (DPB2 . . . DPA2 . . . DPB1 . . . DPA1) and in the same transcriptional orientation (tail-to-tail). The regions in the four species are of approximately the same length and many of the restriction sites are shared between species. The inserts of most Alu elements, of a ribosomal protein pseudogene, and of an IgC epsilon-like pseudogene are found in corresponding positions in all four species. The data indicate that the human-type organization of the DP region was established before the divergence of the Catarrhini and Platyrrhini lines more than 37 million years ago and that it has remained principally intact since that time. This conservation of the DP region is in striking contrast to the evolutionary instability of certain other Mbc regions, in particular those occupied by the DRB or C4 and CYP21 loci. We interpret the stability of the DP region as an indication that the region is being phased out functionally.

Mhc-DRB genes of platyrrhine primates

The two infraorders of anthropoid primates, Platyrrhini (New World monkeys) and Catarrhini (Old World monkeys and the hominoids) are estimated to have diverged from a common ancestor 37 million years ago. The major histocompatibility complex class II DRB gene and haplotype polymorphism of the Catarrhini has been characterized in several recent studies. The present study was undertaken to obtain information on the DRB polymorphism of the Platyrrhini. Fifty-five complete exon 2 DRB sequences were obtained from six species of Platyrrhini representing both the Callitrichidae and the Cebidae families. Combined with the results of a parallel contig mapping study, our data indicate that at least three loci (DRB1*03, DRB3, and DRB5) are shared by the Catarrhini and the Platyrrhini. However, the three loci are occupied by functional genes in the former infraorder and mostly by pseudogenes in the latter. Instead of the pseudogenes, the Platyrrhini have evolved a new set of apparently functional genes-DRB11 and DRB*W12 through DRB*W19, which have thus far not been found in the Catarrhini. The DRB*W13, *W14, *W15, *W17, *W18, and *W19 genes seem to be restricted to the Cebidae family, whereas the DRB*W16 locus has so far been documented in the Callitrichidae family only. The DRB alleles of the cotton-top tamarin, and perhaps also those of the common marmoset (both members of the family Callitrichidae), are characterized by low nucleotide diversity, possibly indicating that they diverged from a common ancestral gene relatively recently.

Qa-2 molecules are peptide receptors of higher stringency than ordinary class I molecules

Class I molecules of the major histocompatibility complex (MHC) transport peptides to the cell surface for surveillance by T cells. Ligand specificity is stringent and differs from allele to allele. Here we report analysis of natural ligands of 'unconventional' glycophosphatidyl-anchored mouse class I molecules, Qa-2. The function of these molecules is unclear; they can serve as recognition structures for 'unrestricted' cytotoxic T cells but have not been found to present peptides to T cells, although the DNA sequence suggests a similar peptide binding groove to that of 'conventional' class I molecules, and other unconventional class I molecules can present antigens in a few cases. Pool sequencing of natural Qa-2 ligands shows that Qa-2 molecules are indeed peptide receptors, having ligand specificity similar to that of conventional class I molecules, that is, a predominant length of nine amino acids, anchor positions, and hydrophobic termination of peptides. But ligand specificity is much more stringent than with other class I molecules: of the nine positions, two are anchors and four have rather limited occupancy.

Trans-species evolution of Mhc-DRB haplotype polymorphism in primates: organization of DRB genes in the chimpanzee

The DRB region of the human major histocompatibility complex displays length polymorphism: Five major haplotypes differing in the number and type of genes they contain have been identified, each at appreciable frequency. In an attempt to determine whether this haplotype polymorphism, like the allelic polymorphism, predates the divergence of humans from great apes, we have worked out the organization of the DRB region of the chimpanzee Hugo using a combination of chromosome walking, pulsed-field gel electrophoresis, and sequencing. Hugo is a DRB homozygote whose single DRB haplotype is some 440 kilobases (kb) long and contains five genes. At least one and possibly two of these are pseudogenes, while three are presumably active genes. The genes are designated DRB*A0201, DRB2*0101, DRB3*0201, DRB6*0105, and DRB5*0301, and are arranged in this order on the chromosome. The DRB2 and DRB3 genes are separated by approximately 250 kb of sequence that does not seem to contain any additional DRB genes. The DRB*A0201 gene is related to the DRB1 gene of the human DR2 haplotype; the DRB2*0101 and DRB3*0201 genes are related to the DRB2 and DRB3 genes of the human DR3 haplotype, respectively; the DRB6*0105 and DRB5*0301 genes are related to the DRBVI and DRB5 genes of the human DR2 haplotype, respectively. Thus the Hugo haplotype appears to correspond to the entire human DR2 haplotype, into which a region representing a portion of the human DR3 haplotype has been inserted. Since other chimpanzees have their DRB regions organized in different ways, we conclude that, first, the chimpanzee DRB region, like the human DRB region, displays length polymorphism; second, some chimpanzee DRB haplotypes are longer than the longest known human DRB haplotypes; third, in some chimpanzee haplotypes at least, the DRB genes occur in combinations different from those of the human haplotypes; fourth, and most importantly, certain DRB gene combinations have been conserved in the evolution of chimpanzees and humans from their common ancestors. These data thus provide evidence that not only allelic but also haplotype polymorphism can be passed on from one species to another in a given evolutionary lineage.

Major-histocompatibility-complex DRB genes of a New-World monkey, the cottontop tamarin (Saguinus oedipus)

The DRB region of the human and great-ape major histocompatibility complex displays not only gene but also haplotype polymorphism. The number of genes in the human DRB region can vary from one to four, and even greater variability exists among the DRB haplotypes of chimpanzees, gorillas, and orangutans. Accumulating evidence indicates that, like gene polymorphism, part of the haplotype polymorphism predates speciation. In an effort to determine when the gene haplotype polymorphisms emerged in the primate lineage, we sequenced three cDNA clones of the New-World monkey, the cottontop tamarin (Saguinus oedipus). We could identify two DRB loci in this species, one (Saoe-DRB1) occupied by apparently functional alleles (*0101 and *0102) which differ by only two nucleotide substitutions and the other (Saoe-DRB2) occupied by an apparent pseudogene. The Saoe-DRB2 gene contains an extra sequence derived from the 3' portion of exon 2 and placed 5' to this exon. This sequence contains a stop codon which makes the translation of the bulk of the Saoe-DRB2 gene unlikely. Preliminary Southern blot hybridization analysis with probes derived from these two genes suggests that both the DRB gene polymorphism and the haplotype polymorphism in the cottontop tamarin may be low. In most individuals the DRB region of this species probably consists of three genes. Comparisons of the Saoe-DRB sequences with those of other primates suggest that probably all of the DRB genes found until now in the Catarrhini were derived from a common ancestor after the separation of the Catarrhini and Platyrrhini lineages. The extant DRB gene and haplotype polymorphism may therefore have been founded in the mid-Oligocene some 33 Mya.

Subtyping of erythrocyte phosphoglucomutase-1 as a genetic marker for bone-marrow engraftment and hematopoietic chimerism after allogeneic bone-marrow transplantation in a patient with acute lymphoblastic leukemia

We report an effective follow-up of the establishment of bone-marrow function after an allogeneic bone-marrow transplantation in a patient with acute lymphoblastic leukemia, by means of a suitable genetic marker, phosphoglucomutase-1 (EC 5.4.2.2) isoenzyme. A patient with acute lymphoblastic leukemia received allogeneic bone-marrow graft from a sibling who was of the same sex and blood group, HLA-identical, and mixed-lymphocyte-culture nonreactive. To monitor the bone-marrow engraftment and the type and degree of chimerism established, we used a genetic marker, the phosphoglucomutase-1 isoenzyme system, to reveal the difference between the bone-marrow host and donor. We did phosphoglucomutase-1 isoenzyme subtyping of the host's and donor's erythrocytes before transplantation, and isoenzyme phenotyping of the host's erythrocytes during a year after transplantation. Establishment of bone-marrow graft function, a period of temporary mixed chimerism with a population of both host's and donor's erythrocytes, a period of the exclusive presence of donor's erythrocytes, and the resumed appearance of host's erythrocytes after eight months, with no signs of relapse of leukemia, were all observed by analysis of phenotypes. These isoenzymes served as a significant and practical genetic marker, which could be successfully used in studies on bone-marrow transplantation.

Subtyping of erythrocyte phosphoglucomutase-1 as a genetic marker for bone-marrow engraftment and hematopoietic chimerism after allogeneic bone-marrow transplantation in a patient with acute lymphoblastic leukemia

We report an effective follow-up of the establishment of bone-marrow function after an allogeneic bone-marrow transplantation in a patient with acute lymphoblastic leukemia, by means of a suitable genetic marker, phosphoglucomutase-1 (EC 5.4.2.2) isoenzyme. A patient with acute lymphoblastic leukemia received allogeneic bone-marrow graft from a sibling who was of the same sex and blood group, HLA-identical, and mixed-lymphocyte-culture nonreactive. To monitor the bone-marrow engraftment and the type and degree of chimerism established, we used a genetic marker, the phosphoglucomutase-1 isoenzyme system, to reveal the difference between the bone-marrow host and donor. We did phosphoglucomutase-1 isoenzyme subtyping of the host's and donor's erythrocytes before transplantation, and isoenzyme phenotyping of the host's erythrocytes during a year after transplantation. Establishment of bone-marrow graft function, a period of temporary mixed chimerism with a population of both host's and donor's erythrocytes, a period of the exclusive presence of donor's erythrocytes, and the resumed appearance of host's erythrocytes after eight months, with no signs of relapse of leukemia, were all observed by analysis of phenotypes. These isoenzymes served as a significant and practical genetic marker, which could be successfully used in studies on bone-marrow transplantation.

Phenotyping of phosphoglucomutase (PGM1) isoenzymes--a new method for the follow-up of chimerism after bone marrow transplantation. Follow-up of chimerism after bone marrow transplantation by phenotyping of phosphoglucomutase (PGM1) isoenzymes

In this study, phenotyping of phosphoglucomutase isoenzymes (PGM1, EC 2.7.5.1) in erythrocytes of bone marrow donors and hosts was shown to present a simple and exact method for the follow-up of chimerism after bone marrow transplantation, aimed at a better assessment of the transplant state and function.