Patients with lipodystrophic diabetes mellitus of the Seip-Berardinelli type, express normal insulin receptors

Lipodystrophic diabetes mellitus of the Seip-Berardinelli type is a syndrome associated with insulin resistance and recessive inheritance. We have examined whether mutations in the insulin receptor are pathogenetic factors in this syndrome. Fibroblasts from three different patients with Seip-Berardinelli's lipodystrophy were tested for insulin binding, and insulin-stimulated receptor autophosphorylation. In addition, the coding region of both alleles of the iinsulin receptor gene was sequenced. No abnormalities in the number of high affinity insulin binding sites, and insulin-stimulated receptor autophosphorylation were detected. The insulin receptor related insulin-like growth factor I receptor also showed no functional changes. DNA sequence analysis of the amplified exons of the insulin receptor gene showed a silent mutation in patient 1 at codon Ser339, changing AGT to AGC. In patient 2 a heterozygous Met for Val substitution at position 985 was detected, which is a rare polymorphism. In patient 3 no mutations, other than described polymorphisms, were observed. These findings demonstrate that the primary genetic lesion in Seip-Berardinelli's lipodystrophy is outside the insulin receptor gene and that an involvement of the insulin-like growth factor I receptor is also unlikely.     

Transitional pre-B-cell acute lymphoblastic leukemia of childhood is associated with favorable prognostic clinical features and an excellent outcome: a Pediatric Oncology Group study

The presenting characteristics and survival of children with the newly recognized transitional cell pre-B immunophenotype of acute lymphoblastic leukemia (ALL) are compared with those of children with pre-B ALL to determine the clinical significance of the new phenotype. Patients with transitional pre-B ALL (n = 17), defined by lymphoblasts expressing cytoplasmic and surface mu heavy chains without kappa or lambda light chains, have lower initial leukocyte counts (p = 0.02) and a higher frequency of DNA indexes > 1.16 (p < 0.001) than patients with pre-B ALL (n = 501), whether or not cases with the unfavorable prognostic (1;19) translocation are included in the analysis. Patients with transitional pre-B ALL lack FAB L3 morphology, bulky extramedullary disease, surface kappa or lambda chains, and the (8;14), (8;22), and (2;8) translocations, features that characterize the syndrome of B-cell ALL. The 4-year relapse-free survival result for children with transitional pre-B ALL appears better than that for children with pre-B ALL (93.3 +/- 17% versus 72.9% +/- 4.6%), but this difference is not statistically significant. We conclude that patients with transitional pre-B ALL have a very favorable prognosis in the context of the therapy used in this study.     

Expression of an abnormal sized c-kit transcript in Hong Kong Chinese acute lymphoblastic leukaemia patients

Blast cells from a majority of acute myelogenous leukaemia (AML) patients express c-kit mRNA. However, c-kit expression has not been observed in patients with acute lymphoblastic leukaemia (ALL) and lymphoproliferative disease. We report here the detection of an abnormal sized c-kit mRNA in two Hong Kong Chinese patients with pre-B ALL and common ALL.     

Bronchoscopic biopsy techniques in the diagnosis and staging of lung cancer

The t(1;19)(q23;p13), detected cytogenetically in 5-6% of cases, is one of the most common translocations in childhood acute lymphoblastic leukemia (ALL). Most t(1;19)+ ALLs are pseudodiploid or contain fewer than 50 chromosomes, are classified as pre-B based on expression of cytoplasmic, but not surface, immunoglobulin (clg+/slg-), express a characteristic pattern of cell surface antigens, and contain E2A-PBX1 fusion mRNAs. A minority of cases are early pre-B (clg-/slg-), do not express the characteristic pattern of cell surface antigens, and lack E2A-PBX1 fusion mRNAs. These latter cases are frequently hyperdiploid, with a modal chromosome number of 55-57. The incidence of the t(1;19) in adults with ALL (approximately 3%) appears to be similar to that observed in children, but the genetic and immunophenotypic features of adult t(1;19)+ ALL have not been described extensively. We report a case of t(1;19)+ ALL occurring in a 38-year-old man in the setting of hyperdiploidy > 50. Despite this feature, this case was pre-B, conformed to the classic t(1;19) immunophenotype, and expressed E2A-PBX1 fusion mRNAs. This prompted us to review the published literature on ploidy and genetic features of t(1;19)+ ALLs. Overall, E2A-PBX1 fusion occurred in 95% (102/107) of t(1;19)+ B-lineage ALLs with 50 or fewer chromosomes, 80% of which were pseudodiploid, vs. only 25% (2/8) of t(1;19)+ ALLs with more than 50 chromosomes.     

What significance to genotype changes have in diagnosis of malignant hyperthermia?

Malignant hyperthermia (MH) is a potentially fatal, inherited pharmacogenetic disorder characterised by a dysfunction of the intracellular calcium regulation. Linkage to DNA markers from the chromosome 19q12-13.2 region and the MHS-phenotype (MH susceptible) has been shown in about 50% of families with a history of MH. The ryanodine receptor gene encoding the human skeletal muscle ryanodine receptor has been localised to the chromosome 19q13.1-13.2 region. The ryanodine receptor, which is an intracellular calcium release channel, has been proposed to be one of the candidate structures for the MH defect. At present, eight different single point mutations have been identified in the human skeletal muscle ryanodine receptor gene in families with disposition to MH. The incidence of the various mutations has been reported as 2-10% each. A combination of different mutations within one pedigree has not been demonstrated. A few years ago, linkage of the MHS-phenotype to DNA markers from the chromosome 17q11.2-24 region was published by an American group. However, this observation has not been confirmed in any of the several European families susceptible to MH. Genes encoding for subunits of the dihydropyridine receptor and the sodium channel of the human skeletal muscle have been found to be located in the chromosome 17q11.2-24 region which, in fact, could be additional candidates for the MH defect. The dihydropyridine receptor is linked to the ryanodine receptor and involved in the calcium regulation of skeletal muscle. Very recent studies have shown linkage to DNA markers from chromosome 7q- and chromosome 3q13.1 regions and the MHS phenotype in two distinct families with history of MH. However, the relevance of this observation is so far unknown. At present, unambiguous preoperative screening of MH disposition based on molecular genetic characteristics is not available because of the enormous heterogeneity of the human MH syndrome. Thus, the halothane-caffeine in-vitro contracture test according to the standard protocol of the "European MH Group" must be performed in order to discover MH susceptibility.     

Molecular analysis of infant acute leukemia

Infant acute leukemia, known to have a poor outcome with conventional therapy, usually has a molecular rearrangement at chromosome band 11q23. The 11q23 translocation partner is typically at 4q21 in infant ALL, but other 11q23 translocation partners occur in infant ALL and AML. The MLL gene at 11q23, and the AF4 gene at 4q21, have been extensively studied to identify heterogeneity of structural rearrangement and prognostic indicators, to look for clues as to etiology, and to improve therapy.     

Analysis of the immunophenotype of children treated on the Medical Research Council United Kingdom Acute Lymphoblastic Leukaemia Trial XI (MRC UKALLXI). Medical Research Council Childhood Leukaemia Working Party

Despite many years of meticulous immunophenotyping of childhood acute lymphoblastic leukaemia (ALL) cases the prognostic significance of some subtypes remains unclear. The Medical Research Council UKALLXI trial (1990-1996) in which uniform treatment has been given to 2090 children with ALL below the age of 18 years and above the age of 1 year, has afforded the opportunity to review these issues. Children with ALL of mature B cell type were not entered into this trial. Immunophenotype analysis was performed in each individual trial centre, but results were centrally reviewed in all cases, and were both available and considered adequate in 1934 (93%) of the first 2090 patients entered. The main diagnostic categories were early pre-B or null reported in 60 cases (3.1%), common ALL in 1242 (64.2%), pre-B in 252 (13.0%), 'common' or pre-B in 172 (8.9%) and T cell in 207 (10.7%) cases. Children with T cell disease were significantly more likely to be over the age of 10 years, with central nervous system disease at diagnosis and to be CD34 negative. They also had a higher incidence of high white cell count and were more likely to be of the French-American-British (FAB) L2 morphological subtype. Patients with 'null' cell disease tended to be less than 2 years or greater than 10 years of age, and CD13 and CD33 positive. CD10 was associated with lower white cell count (WBC) at diagnosis, younger age and FAB L1 morphological subtype. The presence of cytoplasmic immunoglobulin in pre-B cells was not associated with any specific clinical or laboratory features. CD34 positivity was less common in T cell patients and was associated with low WBC. Disease-free survival (DFS) and 95% confidence intervals (CI) at 5 years from diagnosis was 52% (95% CI: 44-59%) for T cell disease, 58% (95% CI: 43-73%) for early pre-B (or null cell) disease and 65% (95% CI: 62-68%) for common or pre-B disease; there being no significant difference between common and pre-B disease with regard to disease outcome. Patients with T cell disease had a worse prognosis than any other immunophenotype group (P < 0.00005). However this worse outcome was no longer significant after allowing for the other principal prognostic factors of age, gender and white cell count at diagnosis except for the very small number with WBC <20 x 10(9)/l and T cell disease. Those with CD10-positive leukaemia did better than those who were CD10 negative (P < 0.00005), with DFS at 5 years 64% (95% CI: 62-67%) for positive vs 56% (95% CI: 49-62%) for CD10 negative. CD10 positivity did not have independent significance when white count, gender and age were taken into account. CD13, CD33, and cytoplasmic mu positivity carried no prognostic significance.     

Human insulin receptor substrate-1 gene (IRS1): chromosomal localization to 2q35-q36.1 and identification of a simple tandem repeat DNA polymorphism

The protein designated as insulin receptor substrate-1 (IRS-1) is a major substrate for the insulin receptor tyrosine kinase. Since post-receptor defects in the insulin signalling pathway are a common feature of Type 2 (non-insulin-dependent) diabetes mellitus, we have cloned the human IRS-1 gene in order to study the role of genetic variation in this gene in the pathogenesis of diabetes mellitus. As a first step in these studies, we have mapped the IRS-1 gene to chromosome 2, bands q35-q36.1 and identified a simple tandem repeat DNA polymorphism in this gene that will be useful for genetic studies.     

Detection of Francisella tularensis by the polymerase chain reaction

A 27-year-old woman and a 13-year-old girl diagnosed with juvenile dermatomyositis in childhood developed clinical findings of partial lipodystrophy 10 years after diagnosis. Exhaustive clinical and laboratory examinations showed an association with other abnormalities: hypertrichosis, steatohepatitis, and an abnormal insulin response to the glucose loading test in the first patient. Hypertrichosis, steatohepatitis, insulin-resistant diabetes mellitus, and acanthosis nigricans were observed in the second patient. Renal function was normal in both patients. Although a localized form of lipodystrophy has been reported associated with connective tissue disease (connective tissue lipoatrophy), the partial form has been infrequently described in association with juvenile dermatomyositis.     

The ob gene product (leptin)--a new hormone of adipose tissue

Obesity--an important problem in modern societies--is caused by energy balance dysregulation and produces numerous adverse effects on health. Recently a particular attention has been paid to molecular and physiological mechanisms in the development of obesity and to the signalling role of adipose tissue in energy stores maintenance on the hypothalamic level. Leptin, the obese gene product discovered in 1995, may play a key role in the feedback system between adipose tissue and the ventromedial nucleus of the hypothalamus (satiety centre). The level of ob gene expression in adipose tissue and plasma leptin concentrations in humans are highly correlated with BMI. So far no mutations in the ob gene in obese subjects have been reported therefore leptin molecule could be active. Despite markedly increased leptin levels found in obesity its central action decreasing food intake and increasing energy expenditure is hindered. Defective ob protein signalling to the brain may be due to receptor and post-receptor defects. Neuropeptide Y, the hypothalamic neurotransmitter involved in the maintaining of energy homeostasis, is a likely candidate for mediating leptin afferent signals. In adipose tissue, the level of ob mRNA is regulated by insulin and glucocorticoids--hormones responsible for glucose homeostasis as well as for the central regulation of feeding behaviour. Until now the character of interactions between leptin and other hormones that regulate energy balance is not known, neither is the exact nature of leptin hypothalamic receptor defect. Defining of the role of leptin in the regulation of satiety and energy expenditure will undoubtedly contribute to a better understanding of the pathogenesis of obesity and its related metabolic complications and may lead to a new treatment approach to human obesity based on leptin or its analogues. At present research work focuses on leptin receptor studies and on ob gene polymorphism and its expression in feeding disorders including obesity and anorexia nervosa. The ob gene is one of a few genes involved in energy balance, however, very promising one.     

Linkage of chromosomal markers on 4q with a putative gene determining maximal insulin action in Pima Indians

Insulin action in vivo varies widely in nondiabetic Pima Indians. Not all of this variance is attributable to individual differences in obesity, physical fitness, sex, or age, and after correcting for these co-variates, measures of insulin action aggregate in families. Insulin action at maximally stimulating insulin concentrations has a trimodal frequency distribution, particularly among obese individuals. This is consistent with the hypothesis that a codominantly inherited autosomal gene, unrelated to obesity, determines MaxM in the population. Preliminary sib-pair linkage analyses indicated the possibility of linkage between MaxM and the GYPA/B locus (encoding the MNSs red cell surface antigens) on chromosome 4q. To confirm and extend these findings, 10 additional loci on 4q were typed in 123 siblings and many of their parents from 46 nuclear families. The results indicate significant (P < 0.001) linkage of the FABP2 and ANX5 loci on 4q with MaxM, and of FABP2 with fasting insulin concentration. No linkage was found between the 4q markers and obesity. Our findings indicate that a gene on 4q, near the FABP2 and ANX5 loci, contributes to in vivo insulin action in Pima Indians.     

Cellular characteristics of acute leukemia cells simultaneously expressing CD13/CD33, CD7 and CD19

Of 832 acute leukemia patients, including 580 acute myeloblastic leukemia (AML), 197 pre-B acute lymphoblastic leukemia (ALL) and 55 pre-T ALL, 26 cases (3.1%) of CD13/CD33+CD7+CD19+ acute leukemia were found. A total of 20 patients were diagnosed as AML, two as pre-B ALL and four as pre-T ALL. Based on the relative intensity of expression of CD7 and CD19, CD13/CD33+CD7+CD19+ acute leukemia patients were subclassified into three categories. Type I (CD7 > CD19) included ten AML and four pre-T ALL, having cellular characteristics similar to CD7+ AML and CD13/CD33+CD7+ ALL. Type II (CD7 < CD19) consisted of four AML with t(8;21) and two pre-B ALL. Type III (CD7 = CD19) included six AML. CD13/CD33+CD7+CD19+ acute leukemia frequently expressed stem cell associated molecules, such as CD34 (88.5%), HLA-DR (96.2%) and mRNA for MDR1 (72.2%), GATA-2 (87.5%) and SCL (25.0%). Simultaneous expression of cytoplasmic CD3 and myeloperoxidase in some leukemia cells implies that CD13/CD33+CD7+CD19+ acute leukemia cells have the potential to differentiate into various lineages. These data suggest that a small population of acute leukemia patients with distinct phenotype, CD13/CD33+CD7+CD19+ acute leukemia, may originate from hematopoietic stem cells.     

Relative biological effectiveness (RBE) of 252Cf fission neutrons for the induction of chromosome damage in human spermatozoa

Severe congenital insulin resistance in the syndrome of leprechaunism is caused by mutations in the insulin receptor gene. We report a patient with leprechaunism who was homozygous for a mutation resulting in the absence of cell surface insulin receptors. To determine whether the receptor for Insulin-like growth factor-I (IGF-I) is involved in the phenotype of leprechaunism, we studied the effect of insulin and of IGF-I on cells from this patient. The patient had a homozygous C-->T substitution at base pair 8212 in exon 12 of the insulin receptor gene, creating a premature stop codon. This nonsense mutation is in the extracellular portion of the receptor and truncates the insulin receptor proximal to its transmembrane anchor, resulting in the absence of cell surface insulin receptors. This finding indicates that complete absence of the insulin receptor is compatible with life. Secondly, DNA synthesis was studied in skin derived fibroblasts in response to increasing concentrations of either insulin or Insulin-like growth factor-I (IGF-I), and was assessed by 3H-thymidine incorporation. In this patient's cells, both of these hormones increased 3H-thymidine incorporation, and the effect was blocked by alpha-IR3, a monoclonal antibody that blocks activation of the IGF-I receptor. These findings confirmed the absence of the insulin receptor and indicated that insulin acts here through activation of the IGF-I receptor. These data support the contention that the phenotypic and metabolic abnormalities of leprechaunism result from the combination of lack of insulin receptor action and over-activation by insulin of the type 1 IGF receptor.     

Identification and partial characterization of two steroid 5 alpha-reductase isozymes in the canine prostate

BACKGROUND AND OBJECTIVE: Intensive induction and post-remission therapies have improved the prognosis in adult acute lymphoblastic leukemia (ALL). However, different from children, the impact of late intensification therapy in the overall results of treatment has not been consistently evaluated. The objective of this study was to analyze the results of a multicenter prospective protocol, PETHEMA ALL-89, in which, after intensive induction and consolidation therapy, randomization to receive delayed intensification treatment was performed. DESIGN AND METHODS: One hundred and eight adults (age > or = 15 years) diagnosed with ALL (ALL L3 excluded) in 22 Spanish hospitals from 1989 to 1994 were treated with a five-drug induction therapy, followed by four cycles of early post-remission treatment during four months, and maintenance therapy for two years. Patients in remission at the end of the first year were randomized to receive one six-week cycle of late intensification therapy. Uni- and multivariate analyses of early response to treatment, complete remission (CR), leukemia-free survival (LFS) and overall survival (OS) were performed. RESULTS: The median (range) age of the series was 28 (15-74) years and leukocyte count 26 x 10(9)/L (1-600). ALL L1/L2 was present in 38/70 patients, early pre-B in 13, common in 53, pre-B in 12 and T in 30 cases. The CR rate was 86%, and refractory disease 9%. Median LFS was 34 months, with a 5-yr probability of 41% (95% CI, 29-53), whereas median OS was 51 months and 5-year probability 47% (34-59%). There were no differences in either LFS and OS between patients who did or did not receive delayed intensification therapy. Prognostic factors for CR attainment were advanced age and slow response to therapy. These two features were, in addition to high leukocyte counts, the parameters with negative influence in both LFS and OS. INTERPRETATION AND CONCLUSIONS: The results of PETHEMA ALL-89 are similar to those referred in other chemotherapy-based protocols in adult ALL. Delayed intensification has not improved the length of remission and survival. Efforts to improve the prognosis of adult ALL patients must be mainly focused in early intensification treatment.     

Heterogeneity of the inhibitory effects of IL-4 in two novel B lineage acute lymphoblastic leukemia cell lines

The present study describes two novel cell lines, DUNATIS and SILVANUS, established from B lineage acute lymphoblastic leukemia patients. Respectively, DUNATIS and SILVANUS display an early pre-B cell and a pre-B cell phenotype. Spontaneous DNA replication of both cell lines was strongly inhibited by IL-4. This effect was directly mediated by IL-4 and exerted through the CD124 IL-4 receptor chain. Notably, IL-4 was associated with rapid cell death and reduction of cellularity in DUNATIS, whereas these parameters were considerably less pronounced and only observed after longer-term exposure of the SILVANUS cells to IL-4. In addition to these differences, although both cell lines expressed FES oncoprotein, a 100 kDa protein associated with FES was strikingly found to be tyrosine-phosphorylated in response to IL-4 exclusively in DUNATIS cells. These data demonstrate that IL-4 displays heterogenous effects on leukemic B cell precursors responsive to inhibition of DNA synthesis via IL-4 mediated engagement of the CD124 receptor chain. The present findings may be of use for appreciation of the effects of IL-4 in B lineage ALL, and the novel cell lines could represent a model for further identification of target molecules in IL-4 signalling.     

Clinical features and molecular genetic analysis of a boy with Prader-Willi syndrome caused by an imprinting defect

Prader-Willi syndrome (PWS) is a neuroendocrine disorder caused by a non-functioning paternally derived gene(s) within the chromosome region 15q11-q13. Most cases result from microscopically visible deletions of paternal origin, or maternal uniparental disomy of chromosome 15. In both instances no recurrence has been reported. In rare cases, PWS is associated with lack of gene expression from the paternal allele due to an imprinting defect. We report the clinical features and the molecular genetic analysis of the first Danish child with PWS due to a defect of the putative imprinting centre (IC). When the imprinting mutation is inherited from a carrier father, the risk that future children will be affected is theoretically 50%. It is therefore important that these families are referred to a geneticist for counselling and further investigation. Prenatal diagnosis is currently only feasible when the mutation has been identified in the affected child.