Methyl-glyoxal bis guanyl hydrazone (methyl-GAG,MGBG) in advanced breast cancer

Summary The Southwest Oncology Group has evaluated methyl-GAG on a weekly schedule among patients with metastatic breast cancer. Among 72 fully and partial evaluable patients, one complete and four partial responses were seen. Toxicity was similar to other trials with this compound except for thrombocytopenia which was more frequent and severe and probably related to tumor infiltrating marrow. In addition, one patient experienced recall dermatitis following methyl-GAG. This toxicity has not been previously reported with this compound. Methyl-GAG has minimal activity at this dose and schedule among heavily pretreated patients with breast cancer. Address for reprints: Southwest Oncology Group (7921), 4450 Medical Drive, San Antonio, TX 78229, U.S.A.     

A Comparative Study of a Group of Eight Calves, Surviving Longer than 1 Month with the Total Artificial Heart

Abstract: Over the last 21/2 years, eight calves with implanted total artificial hearts (from experimental group IV) have survived for >1 month. In this group two subgroups were further differentiated, subgroup IVa, including three calves surviving 31, 35, and 75 days, and subgroup IVb, with five calves surviving 104, 142, 150, and 155 days and one calf still surviving >160 days. Mean survival in the fourth group was > 106.5 days. The artificial ventricles used were the TNS-BRNO-II made of polymethylmethacrylate (seven calves) and the TNS-BRNO-III, made of segmented polyetherurethane (one calf). The controller and driving units were of our own design. The Chirasist-TN-3 and TN-4 worked without trouble over the total duration of the studies in all calves. Autoregulation of suction was used in three of these calves. All calves survived in good physiological condition; however, some common changes were observed in all of them, such as a gradual central venous pressure increase and liver enlargement. Anticoagulation therapy was used in all calves. Causes of death were technical in three cases and biological in four. Body weight gains were normal in the majority of these calves, with slight individual differences observed. Diaphragm mineralization of various degrees was observed in three cases. In one of them it was directly related to the cause of death. These results are very encouraging for further development of the total artifical heart research in our center.     

Induction of de novo α-synuclein fibrillization in a neuronal model for Parkinson’s disease

Lewy bodies (LBs) are intraneuronal inclusions consisting primarily of fibrillized human α-synuclein (hα-Syn) protein, which represent the major pathological hallmark of Parkinson''s disease (PD). Although doubling hα-Syn expression provokes LB pathology in humans, hα-Syn overexpression does not trigger the formation of fibrillar LB-like inclusions in mice. We hypothesized that interactions between exogenous hα-Syn and endogenous mouse synuclein homologs could be attenuating hα-Syn fibrillization in mice, and therefore, we systematically assessed hα-Syn aggregation propensity in neurons derived from α-Syn–KO, β-Syn–KO, γ-Syn–KO, and triple-KO mice lacking expression of all three synuclein homologs. Herein, we show that hα-Syn forms hyperphosphorylated (at S129) and ubiquitin-positive LB-like inclusions in primary neurons of α-Syn–KO, β-Syn–KO, and triple-KO mice, as well as in transgenic α-Syn–KO mouse brains in vivo. Importantly, correlative light and electron microscopy, immunogold labeling, and thioflavin-S binding established their fibrillar ultrastructure, and fluorescence recovery after photobleaching/photoconversion experiments showed that these inclusions grow in size and incorporate soluble proteins. We further investigated whether the presence of homologous α-Syn species would interfere with the seeding and spreading of α-Syn pathology. Our results are in line with increasing evidence demonstrating that the spreading of α-Syn pathology is most prominent when the injected preformed fibrils and host-expressed α-Syn monomers are from the same species. These findings provide insights that will help advance the development of neuronal and in vivo models for understanding mechanisms underlying hα-Syn intraneuronal fibrillization and its contribution to PD pathogenesis, and for screening pharmacologic and genetic modulators of α-Syn fibrillization in neurons.The aggregation of proteins into fibrillar structures is a key hallmark of many neurodegenerative disorders. In Parkinson''s disease (PD), α-synuclein (α-Syn), a predominantly presynaptic protein involved in the regulation of neurotransmitter release, abnormally fibrilizes and forms intraneuronal inclusions termed “Lewy bodies” (LBs) (1, 2). So far, the mechanisms underlying LB formation remain poorly understood, and the impact of LB presence on neuronal viability remains controversial, in part due to the lack of animal models recapitulating α-Syn fibrillization into LB-like inclusions in the brain.Because patients with familial history of parkinsonism were found carrying either multiplications or point mutations of the α-Syn gene SNCA (2), most animal models of PD have been generated by overexpressing WT human α-Syn (hα-Syn) or mutant forms linked to familial PD (3). Strikingly, although rodent models expressing hα-Syn do not recapitulate the formation of fibrillar LBs within dopaminergic neurons, hα-Syn overexpression in Drosophila led to dramatic neuronal loss accompanied with LB-like structures comprising fibrillar α-Syn (4). Drosophila, unlike rodents, do not express an endogenous α-Syn homolog, implying that hα-Syn fibril formation could be more favorable in models lacking endogenous α-Syn expression. Subsequent experiments in mice supported this suggestion, as hα-Syn transgenic (Tg) mice lacking endogenous mouse α-Syn (mα-Syn) expression exhibited exacerbated pathology compared with WT counterparts (5), and manifested fibrillar/granular accumulations in the olfactory bulb (6). Interestingly, in vitro test-tube experiments also showed that small amounts of mα-Syn directly inhibit the fibrillization of purified hα-Syn protein in solution (7).Despite these interesting observations, it remained unclear whether endogenously expressed synuclein homologs directly inhibit hα-Syn aggregation in neurons, and whether ectopic hα-Syn expression in their absence would allow de novo hα-Syn fibrillization events. Therefore, we systematically evaluated the propensity of hα-Syn to aggregate on synuclein-KO backgrounds. Using a battery of biochemical and imaging techniques, we demonstrate that in cultured primary neurons and brains of mα-Syn–KO mice, overexpressed hα-Syn aggregates readily into inclusions that are similar to LBs in terms of solubility, immunoreactivity, and amyloidogenicity, and represent a bona fide fibrillization process as revealed by serial-section transmission electron microscopy (ssTEM), live imaging, and response to pharmacological aggregation inhibitors. Similarly, primary neurons lacking expression of β-Syn (β-Syn^−/−) or of all three homologs (α-, β-, and γ-Syn) also manifest enhanced hα-Syn aggregation, thereby suggesting that endogenous synuclein homologs may represent natural regulators of abnormal α-Syn aggregation. To dissect potential mechanisms underlying this phenomenon, we performed immunoprecipitation and surface plasmon resonance (SPR) experiments, which showed that mα-Syn interacts preferentially with aggregated hα-Syn preformed fibrils (PFFs) rather than with monomers. Importantly, in vitro aggregation experiments and in vivo assessment of cross-seeding propensities of hα-Syn and mα-Syn showed that the observed cross-species interactions attenuate seeding and spreading of aggregates. These findings possibly explain why current rodent PD models expressing hα-Syn do not exhibit pronounced hα-Syn fibrillization, and provide models that reproduce a critical pathological feature of the disease: the de novo formation of fibrillar hα-Syn aggregates.     

Significant decrease in prevalence of Helicobacter pylori in the Czech Republic

AIM: To study possible decrease in prevalence of Helicobacter pylori (H. pylori) infection in the Czech Republic within a 10-year period.METHODS: A total of 22 centres entered the study. The catchment areas of these centres covered cities and towns with more than 20 000 inhabitants, smaller towns (≤ 20 000 inhabitants) with surrounding villages and rural areas, and were spread over the whole country, corresponding well to the geographical distribution of the Czech population. A total of 1 837 subjects (aged 5-98 years) took part in the study, randomly selected out of 38 147 people from the general population. H. pylori infection was investigated by means of a ¹³C-urea breath test. Breath samples in duplicates were analysed using isotope ratio mass spectrometry. The cut-off point was 3.5. Social and demographic characteristics were based on data from self-completed questionnaires.RESULTS: The overall prevalence of H. pylori infection was 23.5% (430/1826), and 4.8% (20/420) in children aged 15 or less. There was no statistically significant difference in prevalence between males (24.3%; 208/857) and females (22.9%, 222/969, P = 0.494). H. pylori infection was strongly associated with higher age, among subjects aged 55+ years, prevalence of H. pylori infection was 39.8% (252/633, P < 0.001). The highest prevalence of H. pylori infection was found among persons aged 55-64 years (43.9%, 97/221) and 75+ years (37.9%, 58/153). Among study subjects aged 15+ years, prevalence of H. pylori infection was significantly increased in those with lowest education (odds risk 3.19, 95% CI 1.87-5.47). Compared to never married (14.1%), the prevalence of H. pylori infection was statistically significantly higher among married (35.4%, 246/694, P < 0.001), divorced (36.8%, 49/133, P < 0.001) and widowed study subjects (40.2%, 45/112, P < 0.001), both in minimally and fully adjusted analysis. There was no significant difference in the prevalence of H. pylori infection between married and widowed subjects (35.4%, 246/694 vs 40.2%, 45/112, P = 0.389). There was little variation in smoking prevalence across categories of smoking and there was no evidence of an increased risk of H. pylori infection among current or past smokers in our data (odds risk 1.04 with 95% CI 0.78-1.40 for current smokers; odds ratio 0.83 with 95% CI 0.60-1.16 for former smokers). The current prevalence of H. pylori in 2011 was significantly lower compared to the prevalence reported from identical geographical areas in 2001 (23.5% vs 41.7%, P < 0.001).CONCLUSION: The overall prevalence of H. pylori infection in the general population has fallen substantially in the Czech Republic over the past 10 years.