11 research outputs found
Modulation of docetaxel treatment
The taxanes are a new class of drugs that exert antitumor activity
through a unique mechanism. As early as in the late 1960s paclitaxel,
extracted from the bark of the Pacific Yew Taxus Brevifolia, was the first
compound with a taxene ring that exhibited antitumor activity.
Because of the difficulties in drug isolation, extraction and formulation, the
development of this antitumor agent has been relatively slow. In 1986
docetaxel, the second drug in this new class of compounds, was
developed. Docetaxel is synthesized from 10-deacetyl baccatin III, a
noncytotoxic precursor extracted from the European Yew Taxus Baccata.
Taxanes promote the polymerization of tubulin into stable
microtubules and inhibit microtubule depolymerization. This leads to a
disruption of the equilibrium within the microtubule system and ultimately
leads to cell death. The activity of docetaxel was studied in many
murine tumor models that showed that docetaxel was active against
subcutaneous B16 melanoma, MX-1 mammary cancer, C38 colon
carcinoma, CX-1 colon carcinoma, LX-1 lung carcinoma, P03
pancreatic carcinoma, SK MEL-2 melanoma and OVCAR,3, HOC 8, HOC
10 and HOC 22 ovarian carcinomas.
In phase I studies on single agent docetaxel responses were reported
in various tumor types such as breast cancer, ovarian cancer,
adenocarcinoma of unknown primary, pancreatic cancer, small cell and
non-small cell lung cance. The major dose limiting toxicity was an
early-onset, short-lasting, dose-dependent, schedule-independent and noncumulative
neutropenia. Other side effects were generally mild and
consisted of alopecia, nausea, vomiting, diarrhea, mucositis, neurotoxicity,
infrequent hypersensitivity reactions, fluid retention and skin- and
nailtoxicity. For phase II studies the recommended dose and schedule was
100 mg/m2 given as a 1-hour infusion every 3 weeks.
Phase II studies on docetaxel among others showed activity in breast
cancer. non-small cell lung cancer, head and neck cancer, gastric cancer, melanoma, soft tissue sarcom), and pancreatic cancer.
In view of the fact that docetaxel is effective in a variety of solid
tumors, it was considered important to study the combination of the drug
with other potent antitumor agents. This thesis includes phase I studies on
the combination of docetaxel with cisplatin and ifosfamide, respectively.
Fluid retention and neurotoxicity, occurring in relation to the cumulative
docetaxel dose, are besides activity important features. At high
cumulative doses of docetaxel these side effects may become severe and
disabling and lead to treatment discontinuation. It is important to try to
alleviate these side effects in view of the single agent use but also in view
of expected increased toxicity in case of combination chemotherapy.
Therefore we performed a prospective study on the incidence of
neurotoxicity induced by the combination of docetaxel and cisplatin, two
potentially neurotoxic drugs.
Despite corticosteroid comedication fluid retention still occurs. In
view of case reports suggesting amelioration of this side effect by
venotonic drugs, we performed a prospective study on the venotonic drug
hydroxyethylrutosiden in patients treated with docetaxel.
The neurotoxicity induced by docetaxel was previously reported in
studies where corticosteroid comedication was not given routinely.
Although introduced to reduce docetaxel-related fluid retention, it was yet
unknown if corticosteroids also had an effect on neurotoxicity. This was
assessed prospectively in the last chapter
Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.
BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362
A Novel D-Galacturonate Fermentation Pathway in Lactobacillus suebicus Links Initial Reactions of the Galacturonate-Isomerase Route With the Phosphoketolase Pathway
D-galacturonate, a key constituent of pectin, is a ubiquitous monomer in plant biomass. Anaerobic, fermentative conversion of D-galacturonate is therefore relevant in natural environments as well as in microbial processes for microbial conversion of pectin-containing agricultural residues. In currently known microorganisms that anaerobically ferment D-galacturonate, its catabolism occurs via the galacturonate-isomerase pathway. Redox-cofactor balancing in this pathway strongly constrains the possible range of products generated from anaerobic D-galacturonate fermentation, resulting in acetate as the predominant organic fermentation product. To explore metabolic diversity of microbial D-galacturonate fermentation, anaerobic enrichment cultures were performed at pH 4. Anaerobic batch and chemostat cultures of a dominant Lactobacillus suebicus strain isolated from these enrichment cultures produced near-equimolar amounts of lactate and acetate from D-galacturonate. A combination of whole-genome sequence analysis, quantitative proteomics, enzyme activity assays in cell extracts, and in vitro product identification demonstrated that D-galacturonate metabolism in L. suebicus occurs via a novel pathway. In this pathway, mannonate generated by the initial reactions of the canonical isomerase pathway is converted to 6-phosphogluconate by two novel biochemical reactions, catalyzed by a mannonate kinase and a 6-phosphomannonate 2-epimerase. Further catabolism of 6-phosphogluconate then proceeds via known reactions of the phosphoketolase pathway. In contrast to the classical isomerase pathway for D-galacturonate catabolism, the novel pathway enables redox-cofactor-neutral conversion of D-galacturonate to ribulose-5-phosphate. While further research is required to identify the structural genes encoding the key enzymes for the novel pathway, its redox-cofactor coupling is highly interesting for metabolic engineering of microbial cell factories for conversion of pectin-containing feedstocks into added-value fermentation products such as ethanol or lactate. This study illustrates the potential of microbial enrichment cultivation to identify novel pathways for the conversion of environmentally and industrially relevant compounds.BT/Industrial MicrobiologyOLD BT/Cell Systems EngineeringBT/Environmental BiotechnologyBT/Biotechnolog
Response rate and prognostic factors of recurrent oligodendroglioma treated with PCV chemotherapy.
“Candidatus Galacturonibacter soehngenii” Shows Acetogenic Catabolism of Galacturonic Acid but Lacks a Canonical Carbon Monoxide Dehydrogenase/Acetyl-CoA Synthase Complex
Acetogens have the ability to fixate carbon during fermentation by employing the Wood-Ljungdahl pathway (WLP), which is highly conserved across Bacteria and Archaea. In a previous study, product stoichometries in galacturonate-limited, anaerobic enrichment cultures of “Candidatus Galacturonibacter soehngenii,” from a novel genus within the Lachnospiraceae, suggested the simultaneous operation of a modified Entner-Doudoroff pathway for galacturonate fermentation and a WLP for acetogenesis. However, a draft metagenome-assembled genome (MAG) based on short reads did not reveal homologs of genes encoding a canonical WLP carbon-monoxide-dehydrogenase/acetyl-Coenzyme A synthase (CODH/ACS) complex. In this study, NaH13CO3 fed to chemostat-grown, galacturonate-limited enrichment cultures of “Ca. G. soehngenii” was shown to be incorporated into acetate. Preferential labeling of the carboxyl group of acetate was consistent with acetogenesis via a WLP in which the methyl group of acetate was predominately derived from formate. This interpretation was further supported by high transcript levels of a putative pyruvate-formate lyase gene and very low transcript levels of a candidate gene for formate dehydrogenase. Reassembly of the “Ca. G. soehngenii” MAG with support from long-read nanopore sequencing data produced a single-scaffold MAG, which confirmed the absence of canonical CODH/ACS-complex genes homologs. However, high CO-dehydrogenase activities were measured in cell extracts of “Ca. G. soehngenii” enrichment cultures, contradicting the absence of corresponding homologs in the MAG. Based on the highly conserved amino-acid motif associated with anaerobic Ni-CO dehydrogenase proteins, a novel candidate was identified which could be responsible for the observed activities. These results demonstrate operation of an acetogenic pathway, most probably as a yet unresolved variant of the Wood-Ljungdahl pathway, in anaerobic, galacturonate-limited cultures of “Ca. G. soehngenii.”BT/Industrial MicrobiologyBT/Environmental BiotechnologyBT/Biotechnolog
Aminotransferases during treatment predict long-term survival in patients with autoimmune hepatitis type 1 : a landmark analysis
A food-grade industrial arming yeast expressing β-1,3-1,4-glucanase with enhanced thermal stability
A highly virulent variant of HIV-1 circulating in the Netherlands.
We discovered a highly virulent variant of subtype-B HIV-1 in the Netherlands. One hundred nine individuals with this variant had a 0.54 to 0.74 log <sub>10</sub> increase (i.e., a ~3.5-fold to 5.5-fold increase) in viral load compared with, and exhibited CD4 cell decline twice as fast as, 6604 individuals with other subtype-B strains. Without treatment, advanced HIV-CD4 cell counts below 350 cells per cubic millimeter, with long-term clinical consequences-is expected to be reached, on average, 9 months after diagnosis for individuals in their thirties with this variant. Age, sex, suspected mode of transmission, and place of birth for the aforementioned 109 individuals were typical for HIV-positive people in the Netherlands, which suggests that the increased virulence is attributable to the viral strain. Genetic sequence analysis suggests that this variant arose in the 1990s from de novo mutation, not recombination, with increased transmissibility and an unfamiliar molecular mechanism of virulence
Human immunodeficiency virus continuum of care in 11 european union countries at the end of 2016 overall and by key population: Have we made progress?
Background. High uptake of antiretroviral treatment (ART) is essential to reduce human immunodeficiency virus (HIV) transmission and related mortality; however, gaps in care exist. We aimed to construct the continuum of HIV care (CoC) in 2016 in 11 European Union (EU) countries, overall and by key population and sex. To estimate progress toward the Joint United Nations Programme on HIV/AIDS (UNAIDS) 90-90-90 target, we compared 2016 to 2013 estimates for the same countries, representing 73% of the population in the region. Methods. A CoC with the following 4 stages was constructed: number of people living with HIV (PLHIV); proportion of PLHIV diagnosed; proportion of those diagnosed who ever initiated ART; and proportion of those ever treated who achieved viral suppression at their last visit. Results. We estimated that 87% of PLHIV were diagnosed; 92% of those diagnosed had ever initiated ART; and 91% of those ever on ART, or 73% of all PLHIV, were virally suppressed. Corresponding figures for men having sex with men were: 86%, 93%, 93%, 74%; for people who inject drugs: 94%, 88%, 85%, 70%; and for heterosexuals: 86%, 92%, 91%, 72%. The proportion suppressed of all PLHIV ranged from 59% to 86% across countries. Conclusions. The EU is close to the 90-90-90 target and achieved the UNAIDS target of 73% of all PLHIV virally suppressed, significant progress since 2013 when 60% of all PLHIV were virally suppressed. Strengthening of testing programs and treatment support, along with prevention interventions, are needed to achieve HIV epidemic control