1,479 research outputs found
An Early-Planted, Early Maturing Soybean Cropping System: Yield and Harvest Losses
Most soybean varieties used In Kentucky, whether grown full season or double-cropped behind wheat or barley, are from Maturity Groups (MG) IV or V. Some MG III varieties are also grown; however, virtually no MG 1/ or earner varieties are planted. Agronomists and soybean producers in Kentucky· have generally felt that MG IV and V varieties produce the highest yield. Since the driest months in Kentucky are August, September,and October, MG IV and V varieties frequently encounter moisture stress during the important seed fill stage. The use of earlier maturing varieties was initially proposed as a means of getting a major portion of seed fill to occur before the driest part of the growing season, thus getting higher yields in dry years
Lumbar spinal stenosis: Assessment of cauda equina involvement by electrophysiological recordings
The objective of this study was to investigate the relationship between electrophysiological recordings and clinical as well as radiological findings in patients suggestive to suffer from a lumbar spinal stenosis (LSS). We hypothesise that the electrophysiological recordings, especially SSEP, indicate a lumbar nerve involvement that is complementary to the neurological examination and can provide confirmatory information in less obvious clinical cases. In a prospective cohort study, 54 patients scheduled for surgery due to LSS were enrolled in an unmasked, uncontrolled trial. All patients were assessed by neurological examination, electrophysiological recordings, and magnetic resonance imaging (MRI) of the lumbar spine. The electrophysiological recordings focused on spinal lumbar nerve involvement. Results: About 88% suffered from a multisegmental LSS and 91% of patients respectively complained of chronic lower back pain and/or leg pain for more than 3 months, combined with a restriction in walking distance. The neurological examination revealed only a few patients with sensory and/or motor deficits while 87% of patients showed pathological electrophysiological recordings (abnormal tibial SSEP in 78% of patients, abnormal H-reflex in 52% of patients). Conclusions: Whereas the clinical examination, even in severe LSS, showed no specific sensory-motor deficit, the electrophysiological recordings indicated that the majority of patients had a neurogenic disorder within the lumbar spine. By the pattern of bilateral pathological tibial SSEP and pathological reflexes associated with normal peripheral nerve conduction, LSS can be separated from a demyelinating polyneuropathy and mono-radiculopathy. The applied electrophysiological recordings, especially SSEP, can confirm a neurogenic claudication due to cauda equina involvement and help to differentiate neurogenic from vascular claudication or musculo-skeletal disorders of the lower limbs. Therefore, electro-physiological recordings provide additional information to the neurological examination when the clinical relevance of a radiologically-suspected LSS needs to be confirme
Conditions currently associated with erythema nodosum in Swiss children
A review was made of the 36 paediatric patients in whom the diagnosis of erythema nodosum had been established between 1977 and 1996 at the Department of Paediatrics, University of Bern, Switzerland. Infectious diseases were associated with erythema nodosum in 20 (including 10 streptococcal infections) and non-infectious inflammatory diseases in 8 patients. None of the 36 patients had tuberculosis or had been exposed to sulphonamides, phenytoin or hormonal contraceptives. There were eight patients in whom either the associated disease was not diagnosed, or there was no other disease. Conclusion Most cases of erythema nodosum are nowadays caused by non-mycobacterial infectious diseases or by non-infectious inflammatory disease
Fructose-induced hyperuricemia is associated with a decreased renal uric Acid excretion in humans.
5-Methyltetrahydrofolate is bound in intersubunit areas of rat liver folate-binding protein glycine N-methyltransferase
Glycine N-methyltransferase (GNMT) is a key regulatory enzyme in methyl group metabolism. It is abundant in the liver, where it uses excess S-adenosylmethionine (AdoMet) to methylate glycine to N-methylglycine (sarcosine) and produces S-adenosylhomocysteine (AdoHcy), thereby controlling the methylating potential of the cell. GNMT also links utilization of preformed methyl groups, in the form of methionine, to their de novo synthesis, because it is inhibited by a specific form of folate, 5-methyltetrahydrofolate. Although the structure of the enzyme has been elucidated by x-ray crystallography of the apoenzyme and in the presence of the substrate, the location of the folate inhibitor in the tetrameric structure has not been identified. We report here for the first time the crystal structure of rat GNMT complexed with 5-methyltetrahydrofolate. In the GNMT-folate complex, two folate binding sites were located in the intersubunit areas of the tetramer. Each folate binding site is formed primarily by two 1-7 N-terminal regions of one pair of subunits and two 205-218 regions of the other pair of subunits. Both the pteridine and p-aminobenzoyl rings are located in the hydrophobic cavities formed by Tyr 5, Leu207, and Met215 residues of all subunits. Binding experiments in solution also confirm that one GNMT tetramer binds two folate molecules. For the enzymatic reaction to take place, the N-terminal fragments of GNMTmust have a significant degree of conformational freedom to provide access to the active sites. The presence of the folate in this position provides a mechanism for its inhibition
Lumbar spinal stenosis: assessment of cauda equina involvement by electrophysiological recordings
The objective of this study was to investigate the relationship between electrophysiological recordings and clinical as well as radiological findings in patients suggestive to suffer from a lumbar spinal stenosis (LSS). We hypothesise that the electrophysiological recordings, especially SSEP, indicate a lumbar nerve involvement that is complementary to the neurological examination and can provide confirmatory information in less obvious clinical cases. In a prospective cohort study, 54 patients scheduled for surgery due to LSS were enrolled in an unmasked, uncontrolled trial. All patients were assessed by neurological examination, electrophysiological recordings, and magnetic resonance imaging (MRI) of the lumbar spine. The electrophysiological recordings focused on spinal lumbar nerve involvement. Results: About 88% suffered from a multisegmental LSS and 91% of patients respectively complained of chronic lower back pain and/or leg pain for more than 3 months, combined with a restriction in walking distance. The neurological examination revealed only a few patients with sensory and/or motor deficits while 87% of patients showed pathological electrophysiological recordings (abnormal tibial SSEP in 78% of patients, abnormal H-reflex in 52% of patients). Conclusions: Whereas the clinical examination, even in severe LSS, showed no specific sensory-motor deficit, the electrophysiological recordings indicated that the majority of patients had a neurogenic disorder within the lumbar spine. By the pattern of bilateral pathological tibial SSEP and pathological reflexes associated with normal peripheral nerve conduction, LSS can be separated from a demyelinating polyneuropathy and mono-radiculopathy. The applied electrophysiological recordings, especially SSEP, can confirm a neurogenic claudication due to cauda equina involvement and help to differentiate neurogenic from vascular claudication or musculo-skeletal disorders of the lower limbs. Therefore, electro-physiological recordings provide additional information to the neurological examination when the clinical relevance of a radiologically-suspected LSS needs to be confirme
Glucose-fructose beverages do not alter the effects of training on lactate metabolism
Glucose-fructose beverages do not alter the effects of training on lactate metabolism
Rosset R., Egli L., Cros J., Schneiter P. and Tappy L. and Lecoultre V.
Department of Physiology, University of Lausanne, Lausanne, Switzerland.
Introduction
It is generally accepted that lactate is produced by skeletal muscle during exercise, and is
either used in adjacent muscle fibers (lactate shuttle) or recycled to glucose in the liver. We
have shown that ingestion of fructose-containing drinks stimulates lactate production and
release from the liver during exercise, and that fructose-derived lactate is subsequently used
as an energy substrate by muscle. The regulation of this liver to muscle fructose-lactate shuttle
remains unknown. In this study, we assessed whether consumption of fructose-containing
beverages alters the effects of training on fructose and lactate metabolism.
Methods
Two groups of eight sedentary male subjects were endurance-trained for three weeks while
ingesting 489 mL/h of either a 9.8%-glucose 6.2%-fructose beverage (GLUFRU) or water (C)
during exercise training sessions. An incremental test to exhaustion and a metabolic test were
performed before and after the interventions to assess training adaptations and substrate use
during endurance-type exercise. Indirect calorimetry, [1-13C]lactate and [6,6-2H2]glucose were
used to calculate plasma lactate appearance, clearance and oxidation and glucose kinetics.
Results
Anthropometrics and performance parameters were similar in both groups at baseline. Plasma
glucose concentrations (+1±3 vs. +3±3 % vs. baseline values), glucose rate of appearance
(+3±7 vs. +2±3 %) and metabolic clearance (+6±8 vs. +1±5 %) remained stable after both
GLUFRU and C training (all p=n.s.). Overall, lactate concentrations were decreased after
intervention in both GLUFRU and C, but not differently between groups (-10±5 vs. -20±4 %;
p<0.01 vs. baseline, p=n.s. between GLUFRU and C), as a result of an increased lactate
metabolic clearance (+26.5±11.4 vs. +17.5±10.2 mL·min-1; p=0.01 vs. baseline, p=0.56
between GLUFRU and C). Lactate appearance (+10±6 vs. -4±9 %) and oxidation (+9±6 vs. -
6±9 %) remained unchanged across time and conditions (all p=n.s.). Maximal oxygen
consumption (+287±53 vs. +249±104 mL·min-1) and power eliciting lactate threshold (+25±5
vs. +25±8 W) were similarly increased in GLUFRU and C (both p<0.01 vs. baseline, p=n.s.
between GLUFRU and C).
Discussion
These data corroborate our earlier observation that fructose is converted into lactate by the
liver and subsequently oxidized during exercise. Endurance training did not alter liver lactate
release, but increased lactate metabolic clearance. The effects of endurance training were not
differently altered by the consumption of fructose during training sessions, however
Gene therapy in patient-specific stem cell lines and a preclinical model of retinitis pigmentosa with membrane frizzled-related protein defects
Defects in Membrane Frizzled-related Protein (MFRP) cause autosomal recessive retinitis pigmentosa (RP). MFRP codes for a retinal pigment epithelium (RPE)-specific membrane receptor of unknown function. In patient-specific induced pluripotent stem (iPS)-derived RPE cells, precise levels of MFRP, and its dicistronic partner CTRP5, are critical to the regulation of actin organization. Overexpression of CTRP5 in naive human RPE cells phenocopied behavior of MFRP-deficient patient RPE (iPS-RPE) cells. AAV8 (Y733F) vector expressing human MFRP rescued the actin disorganization phenotype and restored apical microvilli in patient-specific iPS-RPE cell lines. As a result, AAV-treated MFRP mutant iPS-RPE recovered pigmentation and transepithelial resistance. The efficacy of AAV-mediated gene therapy was also evaluated in Mfrp(rd6)/Mfrp(rd6) mice--an established preclinical model of RP--and long-term improvement in visual function was observed in AAV-Mfrp-treated mice. This report is the first to indicate the successful use of human iPS-RPE cells as a recipient for gene therapy. The observed favorable response to gene therapy in both patient-specific cell lines, and the Mfrp(rd6)/Mfrp(rd6) preclinical model suggests that this form of degeneration caused by MFRP mutations is a potential target for interventional trials
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