A double cryptic chromosome imbalance is an important factor to explain phenotypic variability in Wolf-Hirschhorn syndrome

A total of five Wolf-Hirschhorn syndrome (WHS) patient with a 4p16.3 de novo microdeletion was referred because of genotype-phenotype inconsistencies, first explained as phenotypic variability of the WHS. The actual deletion size was found to be about 12 Mb in three patients, 5 Mb in another one and 20 Mb in the last one, leading us to hypothesize the presence of an extrachromosome segment on the deleted 4p. A der(4)(4qter --> p16.1::8p23 --> pter) chromosome, resulting from an unbalanced de novo translocation was, in fact, detected in four patients and a der(4)(4qter --> q32::4p15.3 --> qter) in the last. Unbalanced t(4;8) translocations were maternal in origin, the rec(4p;4q) was paternal. With the purpose of verifying frequency and specificity of this phenomenon, we investigated yet another group of 20 WHS patients with de novo large deletions (n = 13) or microdeletions (n = 7) and with apparently straightforward genotype-phenotype correlations. The rearrangement was paternal in origin, and occurred as a single anomaly in 19 out of 20 patients. In the remaining patient, the deleted chromosome 4 was maternally derived and consisted of a der(4)(4qter --> 4p16.3::8p23 --> 8pter). In conclusions, we observed that 20% (5/25) of de novo WHS-associated rearrangements were maternal in origin and 80% (20/25) were paternal. All the maternally derived rearrangements were de novo unbalanced t(4;8) translocations and showed specific clinical phenotypes. Paternally derived rearrangements were usually isolated deletions. It can be inferred that a double, cryptic chromosome imbalance is an important factor for phenotypic variability in WHS. It acts either by masking the actual deletion size or by doubling a quantitative change of the genome.     

ErbB2 and the antimetastatic nm23/NDP kinase in regulating serum induced breast cancer invasion

The erbB2 gene is often found amplified and/or overexpressed in breast cancer in which it has clinical relevance as prognostic and predictive factor. It is involved in growth regulation and has a role in the initial phases of cell proliferation, while in vivo and in vitro studies have suggested an involvement also in cell invasion and metastases. It is not clear if these two roles are mutually exclusive and little is known about the mechanisms by which erbB2 may be involved in the control of these processes. Our previous data on patient series suggested that erbB2 might be regulated in different ways depending on the neoplastic status of the cells and that it might be involved in different regulatory pathways. To test this hypothesis we have measured the serum-dependent regulation of erbB2 as a function of the expression of the antimetastatic gene, nm23, in a panel of breast cancer cell lines. The experimental model consisted of three cell lines having different proliferative and invasive potentials: a non-metastatic estrogen receptor (ER) positive cell line, MCF-7; a highly metastatic ER negative cell line, MDA-MB435; and the MDA-MB435 cell line transfected with the nm23-H1 antimetastatic gene (clone H1-177) which has lost the ability to invade and metastasize. We first analysed the serum concentration dependence of invasion and proliferation after 3-4 days of serum deprivation confirming the proliferative and invasive potential of the three cell lines. Modulation of erbB2 expression by different concentrations of serum was then studied. ErbB2 expression in MCF-7 cells showed a complex pattern due to serum modulation, whereas, it was not longer regulated by serum in the MDA-MB435 cell line. In H1-177 cells the erbB2 response to serum was restored and it was very similar to that observed in MCF-7. These data showed a tight association between nm23 and the regulation of erbB2 expression by serum factors suggesting that the role of erbB2 in invasion might be dependent on nm23 expression.     

Juvenile Idiopathic Arthritis

Overexpression of cytokines in inflamed joints plays an important role in joint inflammation and in damage to articular tissue. Biological agents aimed at specifically antagonising tumour necrosis factor (TNF) are effective in the treatment of adult rheumatoid arthritis. A recent trial of etanercept, a genetically engineered fusion protein consisting of the Fc domain of human IgG1 and the TNF receptor p75, has demonstrated that this agent is also well tolerated and effective in patients with juvenile idiopathic arthritis (JIA). Etanercept offers a promising new alternative for patients with JIA who have persistently active arthritis despite treatment with methotrexate. Further studies are needed to clarify whether etanercept is equally effective in the various onset types of JIA (oligoarthritis, polyarthritis and systemic arthritis), whether it can modify disease progression and whether it can be administered safely for long periods of time to children.     

Hepatic Function and Fibrinolysis in Patients with Hereditary Angioedema Undergoing Long-Term Treatment with Tranexamic Acid

Prophylactic treatment with antifibrinolytic agents, epsilon-aminocapriod and tranexamic acid, reduces the incidence and severits of attacks in patients with hereditary angioedema. Long-term ellectivenessor risk of antifibrinolytic agents has not been established. Sixteen patients needing continuous prophylaxis because of frequency and severity of attacks were treated with tranexamic acid. In four patients this treatment was ineffective and the drug was withdrawn after 2 months. A remission or reduction in the frequency or serverity of attacks was observed in 12 patients treated for a period ranging from 8 to 34 months. Hepatic tests and blood fibrinolytic activity were not influenced by long term oral treatment with tranexamic acid.     

Further Survey of Aflatoxin M1 in Milk Powders by ELISA

A survey of AFM₁ residues in 58 commercial milk powder samples was carried out using an enzyme‐linked immunosorbent assay (ELISA) based on a monoclonal antibody against aflatoxin M₁ (AFM₁). The samples were collected from the USA (10), China (28), Italy (14), New Zealand (3) and Poland (3). The ELISA was performed without the need for clean‐up procedures. The data revealed that 4 (US), 21 (Chinese) and 1 (Polish) samples were positive for AFM₁, with an average of 95.5, 102.8 and 85.0 pg g^‐1 of the AFM₁respectively.     

Identification of the three-element windkessel model incorporating a pressure-dependent compliance

A new one-step computational procedure is presented for estimating the parameters of the nonlinear three-element windkessel model of the arterial system incorporating a pressure-dependent compliance. The data required are pulsatile aortic pressure and flow. The basic assumptions are a steadystate periodic regime and a purely elastic compliant element. By stating two conditions, zero mean flow and zero mean power in the compliant element, peripheral and characteristic resistances are determined through simple closed form formulas as functions of mean values of the square of aortic pressure, the square of aortic flow, and the product of aortic pressure with aortic flow. The pressure across as well as the flow through the compliant element can be then obtained so allowing the calculation of volume variation and compliance as functions of pressure. The feasibility of this method is studied by applying it to both simulated and experimental data relative to different circulatory conditions and comparing the results with those obtained by an iterative parameter optimization algorithm and with the actual values when available. The conclusion is that the proposed method appears to be effective in identifying the three-element windkessel even in the case of nonlinear compliance.     

Molecular cytogenetic characterization of a complex rearrangement involving chromosomes 9 and 22 in a case of Ph-negative chronic myeloid leukemia

The "golden path", produced by the Human Genome Project effort, is composed of a collection of overlapping and fully sequenced BAC/PAC clones covering almost completely the human genome. These clones can be advantageously exploited as fluorescence in situ hybridization (FISH) probes for the characterization of rearrangements frequently found in tumors. Breakpoint characterization can be further refined by generating additional smaller FISH probes through LONG-PCR amplification of specific DNA segments, 5-10 kb in size, using appropriate BAC/PAC probes as template. We report here an example of this approach that has been used to characterize a complex Ph-negative chronic myeloid leukemia (CML Ph-) case in which the BCR/ABL fusion gene was found located on chromosome 9.     

Energy dependence of contraction band formation in perfused hearts and isolated adult myocytes.

Aggregation of sarcomeres into contraction bands is a prominent feature of the oxygen paradox, the calcium paradox, and caffeine injury to calcium-free perfused hearts. For investigation of the mechanism of contraction banding, it was necessary to devise a method of evaluating the degree of sarcomere contraction and to define objectively a contraction band. Hearts with mechanical detachment of cells caused by hypocalcemic perfusion and isolated myocytes both allow unrestrained contracture of cells and permit direct optical measurements to quantitate the degree of cell contracture. With the use of the calcium paradox as a model of contraction band necrosis, it was found that cells with lengths of less than 37.3 mu could be considered as containing contraction bands. It was found that the mitochondrial inhibitors cyanide and amytal, as well as the uncoupler 2,4-dinitrophenol, allowed cell contracture but inhibited hypercontracture of sarcomeres into contraction bands during both the calcium paradox and caffeine injury to perfused hearts. However, when 2mM adenosine triphosphate (ATP) was included in the perfusion media, contraction band formation occurred despite the continued presence of cyanide or amytal. In isolated myocyte preparations the addition of the glycolytic inhibitor iodoacetate (IAA, 5 mM) and the mitochondrial inhibitor amytal (3 mM) caused relaxed rod-shaped cells (length/width ratio greater than 3:1) to contract into a stable population of square-shaped forms (length/width ratio less than 3:1), indicating an abrupt and severe decline in cellular ATP levels. Removal of amytal from the incubation medium in the presence of IAA produced a significant conversion of square-shaped cells into round-shaped cells containing contraction bands. Either IAA alone or amytal alone resulted in a mixed population of square and round cells. The results indicate that ATP is required for the formation of contraction bands in intact hearts and for the rounding of isolated myocytes. Formation of contraction bands appears to be an energy-dependent process requiring ATP.     

Memory T lymphocytes generated by Mycobacterium bovis BCG vaccination reside within a CD4 CD44lo CD62 ligand(hi) population

In the lungs of mice vaccinated with Mycobacterium bovis BCG, there was an accumulation of CD4 cells expressing the activated effector phenotype CD44hi CD62 ligandlo) (CD62Llo) which were capable of secreting gamma interferon. Upon cell transfer, however, cells expressing a resting/na?ve phenotype (CD44lo CD62Lhi) were capable of protecting the recipients from a virulent challenge infection, suggesting the emergence of T-cell memory from within this subset.