Increased incidence of mitochondrial cytochrome c-oxidase gene mutations in patients with myelodysplastic syndromes

Mitochondria (mt) play an important role in both apoptosis and haem synthesis. The present study was conducted to determine DNA mutations in mitochondrial encoded cytochrome c-oxidase I and II genes. Bone marrow (BM) biopsy and aspirate, peripheral blood (PB) and buccal smear samples were collected from 20 myelodysplastic syndrome (MDS) patients and 10 age-matched controls. Cytochrome c-oxidase I (CO I) and II (CO II) genes were amplified using polymerase chain reaction and sequenced. CO I mutations were found in 13/20 MDS patients and the CO II gene in 2/10 normal and 12/20 MDS samples, irrespective of MDS subtype. Mutations were substitutional, deletional and insertional. CO I mutations were most common at nucleotide positions 7264 (25%) and 7289 (15%), and CO II mutations were most common at nucleotide positions 7595 (40%) and 7594 (30%), suggesting the presence of potential 'hot-spots'. Mutations were not found in buccal smears of MDS patients and were significantly higher in MDS samples compared with age-matched controls in all cell fractions (P < 0.05), with bone marrow high-density fraction (BMHDF) showing a higher mutation rate than other fractions (P < 0.05). MDS marrows showed higher levels of apoptosis than normal controls (P < 0.05), and apoptosis in BMHDF was directly related to cytochrome c-oxidase I gene mutations (P < 0.05). Electron microscopy revealed apoptosis affecting all haematopoietic lineages with highly abnormal, iron-laden mitochondria. These results suggest a role for mt-DNA mutations in the excessive apoptosis and resulting cytopenias of MDS patients.     

Effect of simultaneous and/or consecutive administration of the broad spectrum anthelmintic flubendazole together with praziquantel in experimental Schistosoma mansoni infection

This study is a trial to demonstrate the effect of the broad spectrum anthelmintic drug flubendazole (methyl 5-(p-fluoro-benzoyl)-2-benzimidazolecarbamate, CAS 31430-15-6), a mebendazole derivative, together with praziquantel (CAS 55268-74-1, EMBAY 8440, Biltricide) in murine schistosomiasis mansoni. Moreover, the relationship between the posttreatment worm burden, oogram pattern, tissue egg load and hepatic granuloma volume was also investigated. Three main groups of Swiss albino mice infected with Schistosoma mansoni cercariae were used in the experiment. Group I included infected untreated control mice. Group II: Subgroup II (a): Animals received 1/3 the dose of praziquantel 25 days post infection. Subgroup II (b): Mice were given 1/3 dose of flubendazole 25 days post infection. Subgroup II (c): Animals received the combination (1/3 dose of flubendazole + 1/3 the dose of praziquantel 25 days post infection. Group III: Subgroup III (a): Mice were given 1/3 the dose of praziquantel 7 weeks post infection. Subgroup III (b): Mice received 1/3 dose of flubendazole 25 days post infection. 24 days later, 1/3 the dose of praziquantel was given. Mice given the consecutive drug regimen (flubendazole 1/3 single oral dose 25 days post infection, then praziquantel 1/3 oral dose for two successive days 24 days later, revealed a significant reduction in the recovery of adult schistosomes after portal perfusion (95.9%), absence of immature stages of ova development, a higher level of dead ova in the oogram and the smallest granuloma mean diameter. These data were less conspicuous in mice given the simultaneous drug regimen.     

Iron-deficiency anemia and protein-energy status in children aged 6 to 59 months in Tunisia

Our study is going to analyse the foodstuffs consumption of the people who have an iron deficiency and then compare it to the consumption of the people who don't have a deficiency. The anemic children who suffer from an iron deficiency have shown an average supply of iron inferior to the required needs which is of 86%. 22.7% of these children have an available iron supply below the recommended average which represents the limit of a severe deficiency risk. No child exceed the severe deficiency risk limit in proteins. 31% of the deficient children have daily energetic supplies inferior to the minimum limit of the daily-required supplies and they are on the brink of a deficiency. The protein needs are common in children but not the energetic ones.     

Fluorescence resonance energy transfer reveals a binding site of a photosensitizer for photodynamic therapy

Phthalocyanine (Pc) 4, like many photosensitizers for photodynamic therapy (PDT), localizes to intracellular membranes, especially mitochondria. Pc 4-PDT photodamages Bcl-2 and Bcl-xL, antiapoptotic proteins interacting with the permeability transition pore complex that forms at contact sites between the inner and outer mitochondrial membranes. These complexes and the inner membrane are unique in containing the phospholipid cardiolipin. Nonyl-acridine orange (NAO) is a specific probe of cardiolipin. Here we show evidence for fluorescence resonance energy transfer from NAO to Pc 4, defining a binding site for the photosensitizer. This observation establishes an innovative tool for exploring the localization of other photosensitizers and additional fluorescent, mitochondrion-localizing drugs having appropriate spectral properties.     

Relationship between elevated levels of the alpha 1 acid glycoprotein in chronic myelogenous leukemia in blast crisis and pharmacological resistance to imatinib (Gleevec) in vitro and in vivo

The Abl tyrosine kinase inhibitor imatinb is becoming a standard for the treatment of chronic myelogenous leukemia (CML). However, Bcr-Abl gene mutations have been reported mainly in relapsing or resistant patients. In primary resistant patients, only few mutations have been documented so far, suggesting alternative mechanisms. We aimed to investigate if alpha 1 acid glycoprotein (AGP), an acute phase drug binding protein, could be a biological marker for pharmacological resistance to imatinib in nine patients in acute phase CML. All patients (3/3) with high AGP dosages (2.31+/-0.17 mg/mL; normal values, 0.5-1.3mg/mL) were primary resistant to imatinib whereas an early clinical response was observed for the six patients with normal AGP levels (1.13+/-0.2mg/mL). No mutation in the adenosine triphosphate domain of Abl were detected before the initiation of imatinib therapy. By using in vitro tests combining various imatinib concentrations (1-10 microM) with purified human AGP (1 and 3 mg/mL), we demonstrate that imatinib-induced apoptosis of K562 or fresh leukemic CML cells is abrogated or reduced. The same effect was observed using sera from donors with high AGP levels (1.9-3.28 mg/mL). In patients with CML in blastic phase, AGP levels could reflect pharmacological resistance to imatinib, suggesting that increased dosage of imatinib or the use of a competitor to drug binding should be recommended to optimize the therapeutic effect of the drug.     

Ability of exercise testing to predict cardiovascular and all-cause death in asymptomatic women: a 20-year follow-up of the lipid research clinics prevalence study

Context  The value of exercise testing in women has been questioned. Objective  To determine the prognostic value of exercise testing in a population-based cohort of asymptomatic women followed up for 20 years. Design and Setting  Near-maximal Bruce-protocol treadmill test data from the Lipid Research Clinics Prevalence Study (1972-1976) with follow-up through 1995. Participants  A total of 2994 asymptomatic North American women, aged 30 to 80 years, without known cardiovascular disease. Main Outcome Measures  Cardiovascular and all-cause mortality. Results  There were 427 (14%) deaths during 20 years of follow-up, of which 147 were due to cardiovascular causes. Low exercise capacity, low heart rate recovery (HRR), and not achieving target heart rate were independently associated with increased all-cause and cardiovascular mortality. There was no increased cardiovascular death risk for exercise-induced ST-segment depression (age-adjusted hazard ratio, 1.02; 95% confidence interval [CI], 0.57-1.80; P = .96). The age-adjusted hazard ratio for cardiovascular death for every metabolic equivalent (MET) decrement in exercise capacity was 1.20 (95% CI, 1.18-1.30; P<.001); for every 10 beats per minute decrement in HRR, the hazard ratio was 1.36 (95% CI, 1.19-1.55; P<.001). After adjusting for multiple other risk factors, women who were below the median for both exercise capacity and HRR had a 3.5-fold increased risk of cardiovascular death (95% CI, 1.57-7.86; P = .002) compared with those above the median for both variables. Among women with low risk Framingham scores, those with below median levels of both exercise capacity and HRR had significantly increased risk compared with women who had above median levels of these 2 exercise variables, 44.5 and 3.5 cardiovascular deaths per 10 000 person-years, respectively (hazard ratio for cardiovascular death, 12.93; 95% CI, 5.62-29.73; P<.001). Conclusion  The prognostic value of exercise testing in asymptomatic women derives not from electrocardiographic ischemia but from fitness-related variables.      

Myelin basic protein-reactive autoantibodies in the serum and cerebrospinal fluid of multiple sclerosis patients are characterized by low-affinity interactions

The presence of autoantibodies to the immunodominant antigen, myelin basic protein (MBP), in the serum and cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS) has been poorly characterized. Many studies report detectable levels of autoantibodies to myelin basic protein though other studies, using similar techniques, report their absence. We compared a solution-phase assay that has detected clinically relevant autoantibodies in diabetes and other autoimmune diseases to solid phase assays similar to those used in previous reports. The solution-phase assay consistently measured autoantibodies to MBP in serum from human subjects with Semple rabies vaccine (SRV)-induced demyelinating disease and from MBP-immunized animals. A solid phase assay detected MBP autoantibodies in the serum of a fraction of patients with MS. Autoantibodies capable of binding to MBP in the solution-phase were not detected in the CSF or serum of patients with MS. Additional solution-phase measurements revealed that anti-MBP antibodies from individuals with SRV-induced demyelinating disease demonstrated a binding affinity profile consistent with that of polyclonal antibodies with a range of affinities from low to high. In contrast, antibodies to MBP in the serum of MS patients detected by ELISA did not bind soluble MBP in the same assay. These results indicate that the humoral response in patients with MS does not include moderate- or high-affinity autoantibodies to MBP.     

Coronary artery disease in postmenopausal women

Opinion statement Many important developments recently have been made in the treatment and prevention of coronary artery disease (CAD) in postmenopausal women. Substantial evidence supports focusing on comprehensive risk factor modification based on the "ABCs" of CAD management from the American College of Cardiology, the American Heart Association, and the American College of Physicians-American Society of Internal Medicine guidelines on chronic stable angina [1•]. This approach emphasizes cardiovascular risk factor interventions that include antiplatelet agents, angiotensinconverting enzyme (ACE) inhibitors, beta-blockers, cholesterol-lowering medications, diabetes control, and counseling on diet and exercise. Despite the expanding available literature, many questions on CAD in postmenopausal women remain unanswered and await the publication of ongoing and future research. The unexpected findings from the HERS (Heart and Estrogen/ progestin Replacement Study) failed to show a benefit of hormone replacement therapy (HRT) in reducing the risk of subsequent events in postmenopausal women with CAD, and instead reported an early increase in CAD events [2]. Based on the data available so far, we advise against starting HRT in postmenopausal women with a recent coronary event for the sole purpose of CAD prevention. For women with acute coronary syndromes, prompt angiography and revascularization should be considered.     

Abnormal thyroid stimulating hormone (TSH) in psychiatric long-term care patients

The objective of the study was to find the prevalence of thyroid dysfunction in long-term care patients referred to psychiatry. We reviewed 868 charts of long-term care residents referred for psychiatric consultation to the university-based psychiatry outreach service. Data obtained were demographics, psychiatric and thyroid diagnoses, and TSH data. Of 868 patients, 10.8% had elevated TSH, 8% in those with a prior diagnosis of hypothyroidism. TSH was low in 0.07%. Elevated TSH was associated with female gender (p < 0.001) and a trend with psychosis (p = 0.056). No association was found with depression or behavioral disturbance in this study.