Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 40
Filter
1.
Nature ; 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38862026

ABSTRACT

Human spaceflight has historically been managed by government agencies, such as the NASA Twins Study1, but new commercial spaceflight opportunities have opened spaceflight to a broader population. In 2021, the SpaceX Inspiration4 mission launched the first-ever all civilian crew to low Earth orbit, which included the youngest American astronaut (age 29), novel in-flight experimental technologies (handheld ultrasound imaging, smartwatch wearables, and immune profiling), ocular alignment measurements, and new protocols for in-depth, multi-omic molecular and cellular profiling. Here we report the primary findings from the 3-day spaceflight mission, which induced a broad range of physiological and stress responses, neurovestibular changes indexed by ocular misalignment, and altered neurocognitive functioning, some of which match long-term spaceflight2, but almost all of which did not differ from baseline (pre-flight) after return to Earth. Overall, these preliminary civilian spaceflight data suggest that short-duration missions do not pose a significant health risk, and moreover present a rich opportunity to measure the earliest phases of adaptation to spaceflight in the human body at anatomical, cellular, physiologic, and cognitive levels. Finally, these methods and results lay the foundation for an open, rapidly expanding biomedical database for astronauts3, which can inform countermeasure development for both private and government-sponsored space missions.

2.
Chem Biol Interact ; 291: 245-252, 2018 Aug 01.
Article in English | MEDLINE | ID: mdl-29964003

ABSTRACT

We conducted an investigation to evaluate the effects of Brazilian Pampa biome honey and its major phenolic compounds on the development of an erected wings posture phenotype and related mitochondrial aspects induced by Hypoxia/Reoxygenation (H/R) in Drosophila melanogaster. Flies were pre-treated for 3 days with a 10% honey solution and different concentrations of caffeic acid and ρ-coumaric acid and then submitted to hypoxia for 3 h. We observed that after reoxygenation, some flies acquired an erected wings posture and that this feature may be related to mortality. In addition, H/R induced down-regulation of ewg mRNA expression, which could be associated to the observed complex phenotype. H/R also caused a dysregulation in opa1-like, ldh and diap genes expression and reduced O2 fluxes in flie's mitochondria. Honey mitigated opa1-like mRNA expression changes provoked by H/R. Differently from honey, caffeic and ρ-coumaric acids displayed no protective effects. In conclusion, we report for the first time the protective effects of honey against complex phenotypes and mitochondrial changes induced by H/R in adult flies.


Subject(s)
Aging/physiology , Drosophila melanogaster/metabolism , Honey , Hypoxia/pathology , Mitochondria/metabolism , Oxygen/pharmacology , Protective Agents/pharmacology , Wings, Animal/metabolism , Animals , Behavior, Animal/drug effects , Cell Respiration/drug effects , Drosophila melanogaster/drug effects , Gene Expression Regulation/drug effects , Locomotion/drug effects , Mitochondria/drug effects , Muscles/cytology , Muscles/drug effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , Wings, Animal/drug effects
4.
Neurochem Res ; 41(1-2): 116-29, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26518676

ABSTRACT

We aimed to investigate the potential beneficial effects of the Brazilian Pampa biome honey in a Drosophila-based hypoxia model. Adult flies were reared in standard medium in the presence or absence of honey (at a final concentration of 10 % in medium). Then, control flies (4 % sucrose in medium) and honey-treated flies were submitted to hypoxia. Subsequently, flies were analyzed for mortality, neurolocomotor behavior (negative geotaxis), mitochondrial/oxidative stress parameters and expression of hypoxia/stress related genes by RT-qPCR. The HPLC analysis revealed the presence of phenolics and flavonoids in the studied honey. Caffeic acid was the major compound followed by p-coumaric acid and kaempferol. The presence of such compounds was correlated with a substantial antioxidant activity in vitro. Flies subjected to hypoxia presented marked mortality, locomotor deficits and changes in oxidative stress and mitochondrial activity parameters. Honey treatment was able to completely block mortality and locomotor phenotypes. In addition, honey was able to reverse ROS production and hypoxia-induced changes in mitochondrial complex I and II activity. Hypoxia also induced an up-regulation in mRNA expression of Sima (HIF-1), NFκß, NRF2, HOX, AKT-1, InR, dILP2, dILP5 and HSP27. Honey treatment was not able to modulate changes in the tested genes, indicating that its protective effects involve additional mechanisms other than transcriptional activity of hypoxia-driven adaptive responses in flies. Our results demonstrated, for the first time, the beneficial effects of honey against the deleterious effects of hypoxia/reperfusion processes in a complex organism.


Subject(s)
Honey , Locomotion , Oxidative Stress , Reperfusion Injury/prevention & control , Animals , Antioxidants/pharmacology , Chromatography, High Pressure Liquid , Drosophila melanogaster/genetics , Flavonoids/analysis , Gene Expression , Honey/analysis , Phenols/analysis , Spectrophotometry, Ultraviolet
7.
J Med Primatol ; 39(4): 243-51, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20618590

ABSTRACT

BACKGROUND: Chronic immune activation is a hallmark of HIV infection and has been postulated as major factor in the pathogenesis of AIDS. Recent evidence suggests that activation of immune cells is triggered by microbial translocation through the impaired gastrointestinal barrier. METHODS: To determine the association between microbial translocation and disease progression, we have retrospectively analyzed microbial products, viral load and markers of immune activation in a cohort of 37 simian immunodeficiency virus-infected rhesus monkeys, divided in two groups with distinct disease courses. RESULTS: As seen in HIV-infected patients, we found elevated levels of lipopolysaccharide (LPS) in infected animals. However, LPS levels or LPS control mechanisms like endotoxin core antibodies or LPS-binding protein did not differ between groups with different disease progression. In contrast, neopterin, a metabolic product of activated macrophages, was higher in fast progressors than in slow progressors. CONCLUSION: Our data indicate that translocation of microbial products is not the major driving force of immune activation in HIV infection.


Subject(s)
Bacterial Translocation , Intestinal Mucosa/microbiology , Simian Acquired Immunodeficiency Syndrome/microbiology , Simian Immunodeficiency Virus , Viral Load , Animals , Cross-Sectional Studies , Intestinal Mucosa/metabolism , Lipopolysaccharides/blood , Macaca mulatta , Retrospective Studies , Simian Acquired Immunodeficiency Syndrome/immunology , beta Carotene/metabolism
10.
Med Hypotheses ; 59(5): 603-6, 2002 Nov.
Article in English | MEDLINE | ID: mdl-12376087

ABSTRACT

The etiology and pathogenesis of major trigeminal neuralgia remain largely unknown, but are believed to result from an irritative lesion near the semilunar ganglion. We suggest that its primary cause is a single, active DNA sequence in the persistent but non-integrated genome of latent herpes simplex virus type 1 commonly observed in a few infected A-delta nerve fibers of the cheek. Facial pain occurs as a result of herpes virus reactivation and when supplies of neurotrophins controlling normal transport functions of axolemmal ion channels become depleted.


Subject(s)
DNA, Viral/genetics , Genes, Immediate-Early , Genes, Viral , Herpes Simplex/complications , Herpesvirus 1, Human/genetics , Trigeminal Neuralgia/etiology , Adult , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Child , Gene Expression Regulation, Viral , Herpes Simplex/genetics , Herpesvirus 1, Human/pathogenicity , Humans , Ion Channels , Models, Neurological , Nerve Growth Factor/physiology , RNA, Viral/biosynthesis , RNA, Viral/genetics , Receptors, Nerve Growth Factor/physiology , Trigeminal Ganglion/virology , Trigeminal Neuralgia/drug therapy , Trigeminal Neuralgia/physiopathology , Trigeminal Neuralgia/virology , Virus Latency/genetics
11.
Horm Metab Res ; 29(12): 604-10, 1997 Dec.
Article in English | MEDLINE | ID: mdl-9497895

ABSTRACT

Since presence of steroid receptors in the human placenta has been the subject of dispute, we have investigated the existence of estrogen (ER) and progesterone (PR) receptors in trophoblasts across gestational age by a variety of different techniques. Fresh human placental tissue of trimesters 1 to 3 was paraffin-embedded or snap-frozen (-80 degrees C) and sliced (5 microns). Other tissue fragments from identical placentae were dispersed and incubated in monolayer cultures for up to 5 days. Immunocytochemistry (ICC) was performed for ER and PR in both trophoblast cells in culture and in whole tissue slices, using the sandwich antibody technique with subsequent horse-radish peroxidase reaction for colorization. In addition, long-term perifusion studies were conducted with explants of term placentae, using perifusion medium with estradiol (E, 2 ng/ml) and/or progesterone (P, 200 ng/ml). Perifused explants were then subjected to further ICC staining. Furthermore, RT-PCR for both ER and PR mRNA was performed for detection of the gene products in placentae of different gestational ages. Lastly, binding studies with iodine or tritium-labeled E and P were conducted on cytosol fractions. In placental sections and cultured trophoblasts, PR was clearly demonstrable in all placentae across different gestational ages. Abundant PR signal was found adjacent to the nuclei, and additionally in the dendrite-like pseudopods of syncytiotrophoblast cells. In contrast, no such staining signal was detected for the ER; this finding applied under all conditions investigated and at all gestational ages. Again, no staining for ER by ICC was detected in any tissue after perifusion with sex steroids. RT-PCR revealed no product for ER, but only for PR, in placentae across all gestational ages. Binding studies with labeled E and P showed no binding for either compound. Taken together, these observations suggest the presence of PR, but not of ER, in human placenta throughout gestation. Our failure to detect the ER does not entirely preclude the presence of this receptor in human trophoblasts, but might be attributed to a relatively low number and density of ER on these cells. Alternatively, estrogen's action on the placenta may be mediated by a different type of ER, such as by a non-classical membrane-bound receptor.


Subject(s)
Placenta/chemistry , Receptors, Estrogen/analysis , Receptors, Progesterone/analysis , Trophoblasts/chemistry , Binding Sites , Cells, Cultured , Culture Techniques , Embryonic and Fetal Development , Estradiol/metabolism , Female , Gestational Age , Humans , Immunohistochemistry , Perfusion , Placenta/metabolism , Polymerase Chain Reaction , Pregnancy , Progesterone/metabolism , Receptors, Estrogen/genetics , Receptors, Progesterone/genetics , Trophoblasts/cytology , Trophoblasts/metabolism
12.
Eur J Endocrinol ; 132(4): 507-13, 1995 Apr.
Article in English | MEDLINE | ID: mdl-7711891

ABSTRACT

Although the peptide hormone relaxin is synthesized by the human corpus luteum in vivo, its potential to serve as a local factor in the regulation of luteal function is not clear. Using an enzyme-linked immunosorbent assay for human relaxin, we detected relaxin in the culture medium of human granulosa-lutein cells as early as after 6 days in culture. Moreover, 1 x 10(5) IU/l human chorionic gonadotropin stimulated relaxin release about fourfold during a 48-h incubation on culture days 6-8 (and 7-9), but not earlier (on days 1, 3 and 4). The stimulatory action of human chorionic gonadotropin on progesterone release was not influenced by relaxin, and relaxin alone was without stimulatory effect. However, human recombinant relaxin (between 0.1 and 12.5 micrograms/l) increased intracellular free Ca2+ basal levels to maximal peak levels exceeding 1000 nmol/l in about 64% of all tested cells (N = 168) with no obvious dependency on the culture day. The relaxin-induced Ca2+ signal was not affected by removal of extracellular Ca2+. As depletion of intracellular Ca2+ stores by ionomycin rendered the cells unresponsive to relaxin or diminished their ability to respond, these results point to an intracellular source of the Ca2+ signal. In summary, our data indicate the presence of a functional relaxin receptor on human granulosa-lutein cells, which is linked to Ca2+ release from intracellular stores.


Subject(s)
Calcium/metabolism , Granulosa Cells/metabolism , Luteal Cells/metabolism , Relaxin/pharmacology , Calcium/pharmacology , Cells, Cultured , Chorionic Gonadotropin/pharmacology , Dose-Response Relationship, Drug , Enzyme-Linked Immunosorbent Assay , Female , Granulosa Cells/cytology , Granulosa Cells/drug effects , Humans , Luteal Cells/cytology , Luteal Cells/drug effects , Progesterone/metabolism , Radioimmunoassay , Relaxin/metabolism , Time Factors
13.
J Neurovirol ; 1(1): 92-100, 1995 Mar.
Article in English | MEDLINE | ID: mdl-9222345

ABSTRACT

Biased hypermutation events found predominantly in the matrix gene of measles virus isolated from persistent human CNS infections have been attributed to the action of a cellular unwinding/modifying activity (UMA). To define the level and distribution of this activity in brain cells, fractionated extracts were prepared from the nuclei and cytoplasm of human glioblastoma (D-54, U-251) and neuroblastoma (IMR-32, SKN-MC) cells and analyzed for their ability to modify synthetic dsRNAs specific for the measles virus (MV) matrix (M) gene. On a quantitative basis we could show that the activity localized to both the nuclear and cytoplasmic compartments of both cell types analyzed independent of cell proliferation. The presence of significant levels of UMA in the cytoplasm of human brain cells following growth arrestment in vitro with retinoic acid supports the interpretation that UMA may contribute to the attenuation of MV gene functions during the primary infection of brain cells, thereby supporting the establishment of virus persistence.


Subject(s)
Measles virus/genetics , Neurons/physiology , Neurons/virology , RNA, Double-Stranded/metabolism , RNA, Viral/metabolism , Cell Differentiation/physiology , Cell Division/physiology , Cytoplasm/chemistry , Cytoplasm/virology , DNA, Viral/analysis , Glioblastoma , Humans , Neuroblastoma , Neuroglia/cytology , Neuroglia/physiology , Neuroglia/virology , Neurons/cytology , RNA, Double-Stranded/analysis , RNA, Viral/analysis , Tumor Cells, Cultured/physiology , Tumor Cells, Cultured/virology
14.
FEBS Lett ; 355(2): 131-4, 1994 Nov 28.
Article in English | MEDLINE | ID: mdl-7982485

ABSTRACT

Exocytosis of secretory granules by adrenal chromaffin cells is blocked by the tetanus toxin light chain in a zinc specific manner. Here we show that cellular synaptobrevin is almost completely degraded by the tetanus toxin light chain within 15 min. We used highly purified adrenal secretory granules to show that synaptobrevin, which can be cleaved by the tetanus toxin light chain, is localized in the vesicular membrane. Proteolysis of synaptobrevin in cells and in secretory granules is reversibly inhibited by the zinc chelating agent dipicolinic acid. Moreover, cleavage of synaptobrevin present in secretory granules by the tetanus toxin light chain is blocked by the zinc peptidase inhibitor captopril and by synaptobrevin derived peptides. Our data indicate that the tetanus toxin light chain acts as a zinc dependent protease that cleaves synaptobrevin of secretory granules, an essential component of the exocytosis machinery in adrenal chromaffin cells.


Subject(s)
Chromaffin Granules/physiology , Membrane Proteins/metabolism , Nerve Tissue Proteins/metabolism , Tetanus Toxin/pharmacology , Amino Acid Sequence , Animals , Cattle , Chromaffin Granules/drug effects , Exocytosis/drug effects , In Vitro Techniques , Membrane Proteins/chemistry , Membrane Proteins/genetics , Molecular Sequence Data , Nerve Tissue Proteins/chemistry , Nerve Tissue Proteins/genetics , Peptide Fragments/chemistry , Peptide Fragments/genetics , Peptide Fragments/metabolism , R-SNARE Proteins , Tetanus Toxin/chemistry
15.
Phys Rev B Condens Matter ; 50(19): 14639-14642, 1994 Nov 15.
Article in English | MEDLINE | ID: mdl-9975698
16.
Eur J Biochem ; 213(1): 537-45, 1993 Apr 01.
Article in English | MEDLINE | ID: mdl-8477726

ABSTRACT

N5-Methyltetrahydromethanopterin:coenzyme M meth-yltransferase is an integral membrane protein found in methanogenic archaea. It catalyzes an energy-conserving step in methane formation from CO2 and from acetate. The enzyme from Methanobacterium thermoautotrophicum (strain Marburg) has been purified 30-fold to apparent homogeneity. The purified enzyme had an apparent molecular mass of 670 kDa and was composed of seven different polypeptides of 34 kDa, 28 kDa, 24 kDa, 23 kDa, 21 kDa, 13 kDa, and 12 kDa. The N-terminal amino acid sequences of these polypeptides were determined. The native 670-kDa enzyme was found to contain 7.6 mol 5-hydroxybenzimidazolyl cobamide/mol, 37 mol non-heme iron/mol and 34 mol acid-labile sulfur/mol. Cobalt analyses after sodium dodecyl sulfate/polyacrylamide gel electrophoresis revealed that the corrinoid was bound to the 23-kDa polypeptide. The apparent molecular masses of the polypeptides given above were determined by sodium dodecyl sulfate/polyacrylamide gel electrophoresis without boiling the samples prior to analysis. When the samples were boiled, as is usually done, the 23-kDa polypeptide changed its apparent molecular mass to 33 kDa and the 21-kDa, 24-kDa, and 28-kDa polypeptides formed aggregates. The specific activity (apparent Vmax) of the purified methyltransferase preparation was 11.6 mumol.min-1.mg protein-1. The apparent Km for N5-methyltetrahydromethanopterin was 260 microM and that for coenzyme M was 60 microM. The preparation was absolutely dependent on the presence of Ti(III) for activity. ATP enhanced the activity 1.5-2-fold.


Subject(s)
Metalloproteins/isolation & purification , Methanobacterium/enzymology , Methyltransferases/isolation & purification , Amino Acid Sequence , Catalysis , Chromatography, Gel , Chromatography, Ion Exchange , Corrinoids , Electrophoresis, Polyacrylamide Gel , Membrane Proteins/chemistry , Membrane Proteins/isolation & purification , Membrane Proteins/metabolism , Metalloproteins/chemistry , Metalloproteins/metabolism , Methyltransferases/chemistry , Methyltransferases/metabolism , Molecular Sequence Data , Molecular Weight , Nonheme Iron Proteins , Vitamin B 12/metabolism
18.
Ann Chir ; 45(2): 100-12, 1991.
Article in French | MEDLINE | ID: mdl-2018328

ABSTRACT

Between January 1972 and October 1984, 412 aortic valve replacements by Bjork-Shiley disk prosthesis were performed. 183 patients suffered from aortic incompetence, 132 from an aortic disease and 97 from aortic stenosis. 116 associated procedures (28%) were performed = 36 myocardial revascularizations, 61 Bentall operations, 12 patch grafts to the ascending aorta and 7 Wheat operations. The mean age was 53.6 years and 25% of the patients were over the age of 65 years. Fifty percent of the patients had stage III or IV disease according to the NYHA classification. The cardiac index was less than 2.3 l/min/m2 in 44.26% of cases. The early postoperative mortality was 4.85% and 20% of these deaths were related to the prosthesis. The late mortality was 17.25%, with 20% of deaths related to the valve. The mean follow-up 59.75 +/- 2 months (range: 1 to 166 months) with a cumulative survival of 2.092 patients-years. It was significantly influence by the existence of preoperative angina, another operation associated with AVR and a cardiac index less than 2.3 l/min/m2. Seventy-one complications were related to the prosthesis including dysfunction (0.05% patient-year), 3 valve thromboses (0.15% patient-year), 6 infected valves (0.31% patient-year), 12 cases of peri-prosthetic dehiscence (0.61% patient-year), 10 embolic complications (0.61% patient-year) and 37 complications related to anticoagulants, including 26 major complications (1.48% patient-year). The valve failure rate was 1.19% patient-year. The results of our series are comparable to those reported in the literature, which confirm the reliability of the Bjork-Shiley Valve.


Subject(s)
Aortic Diseases/surgery , Aortic Valve Insufficiency/surgery , Aortic Valve Stenosis/surgery , Heart Valve Prosthesis/mortality , Actuarial Analysis , Adolescent , Adult , Aged , Aged, 80 and over , Female , Heart Valve Prosthesis/methods , Humans , Male , Middle Aged , Postoperative Complications , Prognosis , Retrospective Studies
20.
Arch Neurol ; 47(4): 382, 1990 Apr.
Article in English | MEDLINE | ID: mdl-2322128
SELECTION OF CITATIONS
SEARCH DETAIL
...