T-cell receptor delta/alpha rearrangements in lymphoid neoplasms

Rearrangements within the T-cell receptor (TCR)delta/alpha locus were analyzed in a wide variety of lymphoid neoplasms by eight DNA probes specific for TCR J delta, J alpha and C alpha segments. In all 11 T- cell malignancies, rearrangement and/or deletion of TCR delta was detected irrespective of the stage of maturation of the tumor. The organization of TCR delta correlated with the phenotype of the tumor: In "prethymic" T-cell acute lymphocytic leukemia (ALL), TCR delta was the only TCR gene to be rearranged. More mature T cell malignancies expressing CD4 together with CD3 showed deletion of both alleles of TCR delta, suggestive of TCR V alpha-J alpha rearrangement. All 43 B-cell tumors expressing surface immunoglobulin (sIg), including two cases of adult B-cell ALL, had germline configuration of TCR delta/alpha. In contrast, all 17 B-cell precursor ALLs (null, common, and pre-B-cell ALLs) had rearrangement and/or deletion of TCR delta/alpha. A single case of "histiocytic" lymphoma also showed biallelic deletion of TCR delta. Oligoclonal rearrangements of Ig and TCR genes were observed in two cases of B-cell precursor ALL and in one case of T-cell lymphoblastic lymphoma. Patterns of such "aberrant" TCR rearrangement were similar to those observed in T-lineage malignancies. In particular, seven of eight cases of B-cell precursor ALL and the histiocytic lymphoma which demonstrated biallelic TCR delta deletion, (suggestive of a V alpha-J alpha rearrangement) had clonal TCR beta rearrangement. These data support the hypothesis that supposedly aberrant rearrangements of the TCR genes may follow the same developmental controls as found in T-cell differentiation, despite the lack of evidence for further commitment to the T-cell lineage. TCR delta rearrangement is a useful marker of clonality of immature T-cell tumors which may have only this gene rearranged but is not specific to the T-cell lineage.     

Sustained, retransplantable, multilineage engraftment of highly purified adult human bone marrow stem cells in vivo

Data from many laboratory and clinical investigations indicate that CD34+ cells comprise approximately 1% of human bone marrow (BM) mononuclear cells, including the progenitor cells of all the lymphohematopoietic lineages and lymphohematopoietic stem cells (stem cells). Because stem cells are an important but rare cell type in the CD34+ cell population, investigators have subdivided the CD34+ cell population to further enrich stem cells. The CD34+/CD38- cell subset comprises less than 10% of human CD34+ adult BM cells (equivalent to < 0.1% of marrow mononuclear cells), lacks lineage (lin) antigens, contains cells with in vitro replating capacity, and is predicted to be highly enriched for stem cells. The present investigation tested whether the CD34+/CD38- subset of adult human marrow generates human hematopoiesis after transfer to preimmune fetal sheep. CD34+/ CD38- cells purified from marrow using immunomagnetic microspheres or fluorescence-activated cell sorting generated easily detectable, long- term, multilineage human hematopoiesis in the human-fetal sheep in vivo model. In contrast, transfer of CD34+/CD38+ cells to preimmune fetal sheep generated only short-term human hematopoiesis, possibly suggesting that the CD34+/CD38+ cell population contains relatively early multipotent hematopoletic progenitor cells, but not stem cells. This work extends the prior in vitro evidence that the earliest cells in fetal and adult human marrow lack CD38 expression. In summary, the CD34+/ CD38- cell population has a high capacity for long-term multilineage hematopoietic engraftment, suggesting the presence of stem cells in this minor adult human marrow cell subset.     

A phase II study of continuous infusion recombinant human granulocyte- macrophage colony-stimulating factor as an adjunct to autologous bone marrow transplantation for patients with non-Hodgkin's lymphoma in first remission

Recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) clearly hastens myeloid recovery in patients with relapsed hematologic malignancies undergoing autologous bone marrow transplantation (ABMT). In efforts to further improve neutrophil engraftment and shorten hospital stay in ABMT patients, rhGM-CSF was administered by a potentially more potent route (continuous infusion) to non-Hodgkin's lymphoma (NHL) patients with better BM reserve (first remission). Time to myeloid engraftment was compared with that of NHL patients treated in first remission at our institution on a similar ABMT protocol but without growth factor support (controls). Median neutrophil engraftment (absolute neutrophil count, 500 cells/microL) in first remission patients treated with rhGM-CSF was 14 days, compared with 22 days in controls (P = .0001). Hospital stays were also significantly reduced for rhGM-CSF patients (P = .0003). Platelet engraftment did not differ between the two groups. Persistent fever and generalized serositis were the primary toxicities. rhGM-CSF, delivered by this route, was efficacious but more toxic than 2-hour rhGM-CSF infusions previously reported by other investigators. Future alterations in both dose and schedule may retain comparable efficacy yet diminish toxicity.     

Maternal obesity and pregnancy outcome: a study of 287,213 pregnancies in London

OBJECTIVE: To examine the maternal and foetal risks of adverse pregnancy outcome in relation to maternal obesity, expressed as body mass index (BMI, kg/m(2)) in a large unselected geographical population. DESIGN: Retrospective analysis of data from a validated maternity database system which includes all but one of the maternity units in the North West Thames Region. A comparison of pregnancy outcomes was made on the basis of maternal BMI at booking. SUBJECTS: A total of 287,213 completed singleton pregnancies were studied including 176,923 (61.6%) normal weight (BMI 20--24.9), 79 014 (27.5%) moderately obese (BMI 25--29.9) and 31,276 (10.9%) very obese (BMI> or =30) women. MEASUREMENTS: Ante-natal complications, intervention in labour, maternal morbidity and neonatal outcome were examined and data presented as raw frequencies and adjusted odds ratios with 99% confidence intervals following logistic regression analysis to account for confounding variables. RESULTS: Compared to women with normal BMI, the following outcomes were significantly more common in obese pregnant women (odds ratio (99% confidence interval) for BMI 25--30 and BMI> or =30 respectively): gestational diabetes mellitus (1.68 (1.53--1.84), 3.6 (3.25--3.98)); proteinuric pre-eclampsia (1.44 (1.28--1.62), 2.14 (1.85--2.47)); induction of labour (2.14 (1.85--2.47), 1.70 (1.64--1.76)); delivery by emergency caesarian section (1.30 (1.25--1.34), 1.83 (1.74--1.93)); postpartum haemorrhage (1.16 (1.12--1.21), 1.39 (1.32--1.46)); genital tract infection (1.24 (1.09--1.41), 1.30 (1.07--1.56)); urinary tract infection (1.17 (1.04-1.33), 1.39 (1.18--1.63)); wound infection (1.27 (1.09--1.48), 2.24 (1.91--2.64)); birthweight above the 90th centile (1.57 (1.50--1.64), 2.36 (2.23--2.50)), and intrauterine death (1.10 (0.94--1.28), 1.40 (1.14--1.71)). However, delivery before 32 weeks' gestation (0.73 (0.65--0.82), 0.81 (0.69--0.95)) and breastfeeding at discharge (0.86 (0.84--0.88), 0.58 (0.56--0.60)) were significantly less likely in the overweight groups. In all cases, increasing maternal BMI was associated with increased magnitude of risk. CONCLUSION: Maternal obesity carries significant risks for the mother and foetus. The risk increases with the degree of obesity and persists after accounting for other confounding demographic factors. The basis of many of the complications is likely to be related to the altered metabolic state associated with morbid obesity.     

Essential thrombocythaemia and the Philadelphia chromosome

Six adult patients presented with clinical features of essential thrombocythaemia. Five of the patients, although Ph-positive, have maintained these features without evidence of leukaemia; in one case for 9 years. A sixth patient developed leukaemic blast crisis following a persistently high platelet count over 4 years. Her cells were Ph-negative, but hybridization of gene probes to chromosomes in situ and to leukaemic DNA showed that the abl oncogene had moved to the breakpoint cluster region (bcr) on the normal chromosome 22. This patient has the same molecular gene change as occurs in some cases of Ph-negative chronic myeloid leukaemia (CML) whose leukaemic cells likewise show no evidence of chromosomal translocation. Molecular studies are essential for the correct diagnosis of these patients. The Ph genomic lesion appears to have a range of leukaemic expression which includes thrombocythaemia as well as chronic myeloid leukaemia and acute lymphatic leukaemia.     

p16INK4A and p15INK4B gene deletions in primary leukemias

The 9p21 locus has been deleted at a high frequency in a wide variety of tumors. Recently, two genes, p16INK4A and p15INK4B (also called MTS1 and MTS2), have been localized in close proximity at the 9p21 locus, encoding cyclin-dependent kinases 4/6 inhibitors of relative molecular mass 16 kD and 15 kD, respectively and also found to be deleted at a high frequency in tumor cell lines. We analyzed p16INK4A and p15INK4B genes in 178 cases of primary leukemias including 81 cases of chronic lymphocytic leukemia (CLL), seven of hairy cell leukemia (HCL), seven of chronic myelogenous leukemia (CML), 43 of acute myelogenous leukemia (AML), 27 of acute lymphoblastic leukemia (ALL), and 13 of myelodysplastic syndrome (MDS) by Southern blot analyses. The ALL cases showed a relatively high frequency of homozygous deletions (22%, 6 of 27) at the p16INK4A gene locus. Interestingly, of the six cases with p16INK4A homozygous deletions, only three showed homozygous deletions at the p15INK4B gene. In 81 CLL patients, we detected one homozygous and five heterozygous deletions at both the p16INK4A and p15INK4B genes and two heterozygous deletions at the p16INK4A gene alone. Deletion of these two genes in AML cases is relatively low (9%). We did not detect deletions in any of the MDS, HCL, and CML cases examined. Sequence analyses of p16INK4A gene of six CLL cases with heterozygous deletion at this locus showed a 27-bp deletion at the splice acceptor site of intron 1 in one case and changes in the coding sequence in three other cases. The data presented in this report showed that (1) p16INK4A and p15INK4B genes are preferentially deleted homozygously in ALL and heterozygously in CLL cases with frequent mutation in the second allele, and (2) p16INK4A gene appears to be more frequently deleted than p15INK4B gene.     

Ph-negative chronic myeloid leukaemia

An analysis of five patients with Philadelphia chromosome (Ph) negative chronic myeloid leukaemia (CML) revealed that two were clinically and haematologically identical to Ph-positive CML whereas three should be reclassified as chronic myelomonocytic leukaemia (CMML). At a molecular level the first two patients showed the same juxtaposition of c-abl and bcr genes as is seen in Ph-positive CML. These genomic changes were not seen in the other three patients. Observations on these five patients suggest that the clinical course and prognosis of the rare patient who carries the Ph 'molecular defect' but lacks the Philadelphia chromosome is no different from Ph-positive CML.     

PLP1 gene analysis in 88 patients with leukodystrophy

Pelizaeus–Merzbacher disease (PMD) is caused in most cases by either duplications or point mutations in the PLP1 gene. This disease, a dysmyelinating disorder affecting mainly the central nervous system, has a wide clinical spectrum and its causing mutations act through different molecular mechanisms. Eighty‐eight male patients with leukodystrophy were studied. PLP1 gene analysis was performed by the Multiplex Ligation‐dependent Probe Amplification technique and DNA sequencing, and, in duplicated cases of PLP1, gene dosage was completed by using array‐CGH. We have identified 21 patients with mutations in the PLP1 gene, including duplications, short and large deletions and several point mutations in our cohort. A customized array‐CGH at the Xq22.2 area identified several complex rearrangements within the PLP1 gene region. Mutations found in the PLP1 gene are the cause of PMD in around 20% of the patients in this series.     

Uncertainties surrounding the choice of surgical treatment for ‘bone on bone’ medial compartment osteoarthritis of the knee

A number of different surgical interventions can be used for treating antero-medial osteoarthritis (AMOA) of the knee and this choice can present challenges for patient's decision-making. Patients with AMOA can undergo Total Knee Replacement (TKR), Unicompartmental Knee Replacement (UKR) or High Tibial Osteotomy (HTO) for the same pathology. However many uncertainties still exist as to deciding which operation is best for individual patients and the Orthopaedic community has failed to systematically compare treatment options. The relative lack of scientifically based evidence has impacted on the ability to provide clear guidelines on treatment choice, patient suitability and direct patient preference for treatment. This paper, using available evidence, discusses the issue and offers some suggestions for future development.