Three patients with structurally abnormal X chromosomes, each with Xq13 breakpoints and a history of idiopathic acquired sideroblastic anemia

Structural abnormalities of the X chromosome are rarely found in neoplastic disorders. We describe three patients with a history of idiopathic acquired sideroblastic anemia (IASA); each one had an abnormal clone of cells in the bone marrow, characterized by a structurally abnormal X chromosome. In two of these patients, the predominant karyotype was 47,X,2idic(X)(q13); in the other patient, it was 46,X,t(X;11)(q13;p15). Inasmuch as all three of these cases involved chromosome band Xq13, as did two previously published cases, we suggest that band Xq13 may be more prone to structural rearrangement than other X chromosome bands in hematologic disorders. The common Xq13 chromosome breakpoint and clinical presentation (IASA) among these three patients and the occurrence of an X-linked type of sideroblastic anemia may suggest that an association exists between X chromosome abnormalities and IASA. Perhaps alteration of a gene or chromosome structure in or near band Xq13 predisposes to development of IASA. The fact that two of these patients had preleukemia and the third had overt acute leukemia may imply that patients with IASA and X chromosome abnormalities have a poor prognosis. Cases of IASA without associated X chromosome abnormalities are known; thus, if an association between IASA and an abnormal X chromosome does exist, most likely it involves only some patients with IASA.     

An effective Australian-Chinese peer education program on HIV/AIDS/STDs for university students in China

<正> IntroductionCurrently,there are at least 850,000 peo-ple living with human immuno-deficiency virus(HIV) and acquired immuno-deficiency syn-drome (AIDS) in China.Among them 16-29years old account for about 65%.Accordingto the Chinese health authorities,if the pre-ventive measures are not effective,the figurecould reach as many as 10 million by the year2010.Since there are currently no cure or     

The immunocompromised district: a unifying concept for lymphoedematous, herpes-infected and otherwise damaged sites

Systemic immunodeficiency is known to facilitate the onset of opportunistic infections, tumours and immune disorders in any district of the body. There are clinical events, such as chronic lymphoedema, herpetic infections, vaccinations and heterogeneous physical injuries which can selectively damage and immunologically mark the cutaneous district they act upon. After the causing event has disappeared, the affected district may appear clinically normal, but its immune behaviour is often compromised forever. An immunocompromised district becomes a site which is particularly susceptible to subsequent outbreaks of opportunistic infections, tumours and immune disorders confined to the district itself.
In this review, there is an ample case-report collection of opportunistic disorders (infectious, neoplastic, immune) which appeared in immunocompromised districts. The cases have been grouped according to the clinical settings responsible for the local immune imbalance: regional chronic lymphoedema; herpes-infected sites, which feature the well-known Wolf's isotopic response; and otherwise damaged areas, comprising sites of vaccination, ionizing or UV radiation, thermal burns and traumas.
Whatever the immunocompromising factor, a common denominator which facilitates the occurrence of tumours, infections and dysimmune reactions in an immunocompromised district may reside in locally hampered lymph drainage and/or locally altered neuromediator signalling. In fact, any obstacle to the normal trafficking of immunocompetent cells through lymphatic channels or any interference with the signals that the neuropeptides and neurotransmitters released by peripheral nerves send to cell membrane receptors of immunocompetent cells, can significantly alter the local immune response, thus paving the way for heterogeneous opportunistic disorders in the immunocompromised district.     

Cytotoxic T-cell responses show more restricted specificity for self than for non-self H-2D-coded antigens

The specificity of recognition of H-2 antigens by various subsets of Tc cells was investigated with respect to the two separate molecules known to be coded in the H-2D(d) region (a) D which carries the private specificity H-2.4 and (b) D’which carries the public specificity H-2.28. BALB/c.H-2(db) mutant mice express D but not D’ on their cell surfaces, whereas wild-type BALB/c mice express both D and D’. H-2 restricted Tc cells specific for viral-plus- H-2D(d)-coded antigens on infected self cells, or minor H-plus-H-2D(d)-coded antigens on H-2-compatible cells apparently recognize D, but do not detectably recognize D. In contrast, BALB/c-H-2(db) anti-BALB/c Tc cell responses do recognize D’ (the only known antigen which is not shared by mutant and wild-type); furthermore, D’ is also detectably recognized by a significant proportion of the Tc cells that respond in MLR to H-2D(d)-coded antigens. In these latter responses, D’ was recognized separately from D, i.e., the response was not “H-2 restricted”. These results indicate that H-2 restricted Tc cell responses to modified-self cells are more specific for self H-2D(d)-coded antigens then are allogeneic Tc cell responses directed at the same antigens, in that haplotype-unique (private) specificity recognition (of the D molecule) exclusively occurs only in the former, not the latter case. The implications of this specificity of H-2 restricted responses for possible processes of somatic selection of anti-self recognition structures on progenitor Tc cells are briefly discussed.     

Circulating glycosaminoglycan anticoagulants associated with suramin treatment

A complex coagulopathy appeared in three women receiving suramin as treatment for metastatic adrenocortical carcinoma. Although hepatocellular dysfunction accounted for some of the abnormality, a unique feature of the coagulopathy was the presence of an inhibitor of the thrombin clotting time. The potency of this circulating anticoagulant increased markedly during exacerbations of hepatic injury. The anticoagulant was removed from plasma samples from two of the patients by passage over a column of diethylaminoethyl (DEAE)- Sephacel. It eluted from the DEAE at salt concentrations that removed "high-charge" glycosaminoglycans. Elimination of the purified anticoagulant activity in vitro required a combination of heparitinase and chondroitinase ABC, suggesting that the activity was mediated by both heparan sulfate and dermatan sulfate. Suramin is hypothesized to inhibit enzymes that normally degrade glycosaminoglycans, resulting in accumulation of these substances, which are released from the liver into the circulation during periods of hepatic injury.     

Eliminating right ventricular pacing may not be best for patients requiring implantable cardioverter-defibrillators

BACKGROUND: Excessive right ventricular (RV) pacing has been associated with adverse clinical outcomes in patients receiving pacemakers or implantable cardioverter-defibrillators (ICDs). It remains uncertain how much RV pacing is clinically deleterious. OBJECTIVE: This retrospective analysis assessed the relationship between the amount of RV pacing and the composite of all-cause mortality and heart failure hospitalization in all patients programmed DDDR in the Inhibition of Unnecessary RV Pacing with AV Search Hysteresis in ICDs (INTRINSIC RV) study. METHODS: Seven hundred fifteen patients consistently programmed to DDDR mode throughout follow-up (mean 11.6 months) were examined. The relationship between RV pacing tier and death and heart failure hospitalization was determined and compared with patient characteristics. RESULTS: Across the six RV pacing tiers, patients differed significantly with respect to age, clinical history of ventricular tachycardia, atrial fibrillation, and atrial flutter, and amiodarone use. When controlling for these baseline differences, the best outcome was seen in the group with RV pacing between 10% and 19% (2.8% event rate; n = 106). Increasing levels of RV pacing were generally predictive of higher event rates (death or heart failure hospitalization; P = 0.003), except for the group (n = 344) with the least amount of RV pacing (0-9%). This group exhibited poorer outcomes than otherwise expected (P = 0.016), with 8.1% of these patients experiencing an event. CONCLUSIONS: High levels of RV pacing are associated with heart failure hospitalization and mortality in a large ICD population. However, ICD patients with some RV pacing (10%-19%) exhibit lower event rates compared with those with very low levels (0-9%), possibly due to the physiologically appropriate nature of that RV pacing.     

Antisense oligodeoxynucleotide combination therapy of primary chronic myelogenous leukemia blast crisis in SCID mice

The proliferation of chronic myelogenous leukemia (CML) cells and the transformation of normal hematopoietic cells by BCR-ABL appear to require the expression of a functional MYC protein, suggesting an approach to treatment of Philadelphia leukemias based on simultaneous targeting of BCR-ABL and c-MYC. To test this hypothesis, CML-blast crisis (CML-BC) primary cells were treated in vitro with bcr-abl and c- myc antisense phosphorothioate oligodeoxynucleotides ([S]ODNs), individually or in combination. Compared with antisense ODNs targeting of individual oncogenes, downregulation of both BCR-ABL and c-MYC by specific antisense [S]ODNs resulted in a synergistic antiproliferative effect. Colony formation of normal bone marrow cells was not affected by either treatment. To assess the therapeutic potential of multiple oncogene downregulation, SCID mice injected with CML-BC primary cells were treated systematically with equal doses of bcr-abl or c-myc antisense [S]ODNs or with a combination of both antisense [S]ODNs. Compared with mice treated with individual compounds, the disease process was significantly retarded in the group treated with both [S]ODNs as revealed by flow cytometry, clonogenic assay, and RT-PCR analysis to detect leukemic cells in mouse tissue cell suspensions. These effects correlated with a markedly increased survival of leukemic mice treated with both antisense [S]ODNs. Leukemic cells harvested from antisense [S]ODN-treated mice were sensitive to the effects of antisense [S]ODNs in vitro, suggesting that the treatment can be successfully repeated. These data demonstrate the therapeutic potential of targeting multiple cooperating oncogenes.