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1.
ISME J ; 16(6): 1523-1533, 2022 06.
Article in English | MEDLINE | ID: mdl-35124702

ABSTRACT

The reduction of manganese oxide with sulfide in aquatic redox-stratified systems was previously considered to be mainly chemical, but recent isolation of the Black Sea isolate Candidatus Sulfurimonas marisnigri strain SoZ1 suggests an important role for biological catalyzation. Here we provide evidence from laboratory experiments, field data, and modeling that the latter process has a strong impact on redox zonation in the Black Sea. High relative abundances of Sulfurimonas spp. across the redoxcline in the central western gyre of the Black Sea coincided with the high-level expression of both the sulfide:quinone oxidoreductase gene (sqr, up to 93% expressed by Sulfurimonas spp.) and other sulfur oxidation genes. The cell-specific rate of manganese-coupled sulfide oxidation by Ca. S. marisnigri SoZ1 determined experimentally was combined with the in situ abundance of Sulfurimonas spp. in a one-dimensional numerical model to calculate the vertical sulfide distribution. Abiotic sulfide oxidation was too slow to counterbalance the sulfide flux from euxinic water. We conclude that microbially catalyzed Mn-dependent sulfide oxidation influences the element cycles of Mn, S, C, and N and therefore the prevalence of other functional groups of prokaryotes (e.g., anammox bacteria) in a sulfide-free, anoxic redox zone.


Subject(s)
Manganese , Water , Black Sea , Oxidation-Reduction , Seawater/microbiology , Sulfides/metabolism
2.
Biomaterials ; 247: 119998, 2020 07.
Article in English | MEDLINE | ID: mdl-32251928

ABSTRACT

Many skeletal tissue regenerative strategies centre around the multifunctional properties of bone marrow derived stromal cells (BMSC) or mesenchymal stem/stromal cells (MSC)/bone marrow derived skeletal stem cells (SSC). Specific identification of these particular stem cells has been inconclusive. However, enriching these heterogeneous bone marrow cell populations with characterised skeletal progenitor markers has been a contributing factor in successful skeletal bone regeneration and repair strategies. In the current studies we have isolated, characterised and enriched ovine bone marrow mesenchymal stromal cells (oBMSCs) using a specific antibody, Stro-4, examined their multipotential differentiation capacity and, in translational studies combined Stro-4+ oBMSCs with a bovine extracellular matrix (bECM) hydrogel and a biocompatible melt electro-written medical-grade polycaprolactone scaffold, and tested their bone regenerative capacity in a small in vivo, highly vascularised, chick chorioallantoic membrane (CAM) model and a preclinical, critical-sized ovine segmental tibial defect model. Proliferation rates and CFU-F formation were similar between unselected and Stro-4+ oBMSCs. Col1A1, Col2A1, mSOX-9, PPARG gene expression were upregulated in respective osteogenic, chondrogenic and adipogenic culture conditions compared to basal conditions with no significant difference between Stro-4+ and unselected oBMSCs. In contrast, proteoglycan expression, alkaline phosphatase activity and adipogenesis were significantly upregulated in the Stro-4+ cells. Furthermore, with extended cultures, the oBMSCs had a predisposition to maintain a strong chondrogenic phenotype. In the CAM model Stro-4+ oBMSCs/bECM hydrogel was able to induce bone formation at a femur fracture site compared to bECM hydrogel and control blank defect alone. Translational studies in a critical-sized ovine tibial defect showed autograft samples contained significantly more bone, (4250.63 mm3, SD = 1485.57) than blank (1045.29 mm3, SD = 219.68) ECM-hydrogel (1152.58 mm3, SD = 191.95) and Stro-4+/ECM-hydrogel (1127.95 mm3, SD = 166.44) groups. Stro-4+ oBMSCs demonstrated a potential to aid bone repair in vitro and in a small in vivo bone defect model using select scaffolds. However, critically, translation to a large related preclinical model demonstrated the complexities of bringing small scale reported stem-cell material therapies to a clinically relevant model and thus facilitate progression to the clinic.


Subject(s)
Mesenchymal Stem Cells , Animals , Bone Marrow , Bone Marrow Cells , Cattle , Cell Differentiation , Cells, Cultured , Extracellular Matrix , Hydrogels , Osteogenesis , Polyesters , Sheep
3.
Anim Genet ; 51(1): 137-140, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31729778

ABSTRACT

Black and tan animals have tan-coloured ventral body surfaces separated by sharp boundaries from black-coloured dorsal body surfaces. In the at mouse mutant, a retroviral 6 kb insertion located in the hair cycle-specific promoter of the murine Asip gene encoding agouti signalling protein causes the black and tan phenotype. In rabbits, three ASIP alleles are thought to exist, including an at allele causing a black and tan coat colour that closely resembles the mouse black and tan phenotype. The goal of our study was to identify the functional genetic variant causing the rabbit at allele. We performed a WGS-based comparative analysis of the ASIP gene in one black and tan and three wt agouti-coloured rabbits. The analysis identified 75 at -associated variants including an 11 kb deletion. The deletion is located in the region of the hair cycle-specific ASIP promoter and thus in a region homologous to the site of the retroviral insertion causing the at allele in mice. We observed perfect association of the genotypes at this deletion with the coat colour phenotype in 49 rabbits. The comparative analysis and the previous knowledge about the regulation of ASIP expression suggest that the 11 kb deletion is the most likely causative variant for the black and tan phenotype in rabbits.


Subject(s)
Agouti Signaling Protein/genetics , Exons , Hair Color/genetics , Promoter Regions, Genetic , Rabbits/genetics , Sequence Deletion , Alleles , Animals , Phenotype
4.
Anim Genet ; 50(6): 761-763, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31463981

ABSTRACT

White spotting phenotypes in horses may be caused by developmental alterations impairing melanoblast differentiation, survival, migration and/or proliferation. Candidate genes for white-spotting phenotypes in horses include EDNRB, KIT, MITF, PAX3 and TRPM1. We investigated a German Riding Pony with a sabino-like phenotype involving extensive white spots on the body together with large white markings on the head and almost completely white legs. We obtained whole genome sequence data from this horse. The analysis revealed a heterozygous 1273-bp deletion spanning parts of intron 2 and exon 3 of the equine KIT gene (Chr3: 79 579 925-79 581 197). We confirmed the breakpoints of the deletion by PCR and Sanger sequencing. Knowledge of the functional impact of similar KIT variants in horses and other species suggests that this deletion represents a plausible candidate causative variant for the white-spotting phenotype. We propose the designation W28 for the mutant allele.


Subject(s)
Hair Color , Horses/genetics , Stem Cell Factor/genetics , Animals , Exons
5.
Anim Genet ; 50(2): 172-174, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30644113

ABSTRACT

White spotting phenotypes in horses are highly valued in some breeds. They are quite variable and may range from the common white markings up to completely white horses. EDNRB, KIT, MITF, PAX3 and TRPM1 represent known candidate genes for white spotting phenotypes in horses. For the present study, we investigated an American Paint Horse family segregating a phenotype involving white spotting and blue eyes. Six of eight horses with the white-spotting phenotype were deaf. We obtained whole-genome sequence data from an affected horse and specifically searched for structural variants in the known candidate genes. This analysis revealed a heterozygous ~63-kb deletion spanning exons 6-9 of the MITF gene (chr16:21 503 211-21 566 617). We confirmed the breakpoints of the deletion by PCR and Sanger sequencing. PCR-based genotyping revealed that all eight available affected horses from the family carried the deletion. The finding of an MITF variant fits well with the syndromic phenotype involving both depigmentation and an increased risk for deafness and corresponds to human Waardenburg syndrome type 2A. Our findings will enable more precise genetic testing for depigmentation phenotypes in horses.


Subject(s)
Deafness/veterinary , Gene Deletion , Horse Diseases/genetics , Horses/genetics , Microphthalmia-Associated Transcription Factor/genetics , Animals , Color , Deafness/genetics , Female , Male , Microphthalmia-Associated Transcription Factor/metabolism , Pigmentation/genetics , Risk Factors , Whole Genome Sequencing/veterinary
6.
J Tissue Eng Regen Med ; 11(7): 2081-2089, 2017 07.
Article in English | MEDLINE | ID: mdl-26648044

ABSTRACT

The properties of osteoblasts (OBs) isolated from the axial skeleton (tOBs) differ from OBs of the orofacial skeleton (mOBs) due to the different embryological origins of the bones. The aim of the study was to assess and compare the regenerative potential of allogenic bone marrow-derived mesenchymal progenitor cells with allogenic tOBs and allogenic mOBs in combination with a mPCL-TCP scaffold in critical-sized segmental bone defects in sheep tibiae. After 6 months, the tibiae were explanted and underwent biomechanical testing, micro-computed tomography (microCT) and histological and immunohistochemical analyses. Allogenic MPCs demonstrated a trend towards a better outcome in biomechanical testing and the mean values of newly formed bone. Biomechanical, microCT and histological analysis showed no significant differences in the bone regeneration potential of tOBs and mOBs in our in vitro study, as well as in the bone regeneration potential of different cell types in vivo. Copyright © 2015 John Wiley & Sons, Ltd.


Subject(s)
Bone Regeneration , Mesenchymal Stem Cell Transplantation , Mesenchymal Stem Cells/metabolism , Osteoblasts , Tibia/injuries , Tibia/metabolism , Tissue Scaffolds , Allografts , Animals , Osteoblasts/metabolism , Osteoblasts/transplantation , Osteogenesis , Sheep , Tibia/diagnostic imaging , Tissue Engineering/methods , X-Ray Microtomography
7.
Water Sci Technol ; 63(12): 3034-8, 2011.
Article in English | MEDLINE | ID: mdl-22049735

ABSTRACT

The alpha-factor has the greatest impact on the calculation of the required standard oxygen transfer rate (SOTR) in activated sludge systems equipped with submerged aeration systems. Knowing the dependencies of the alpha-factor leads to a better design of the aeration devices and, consequently, to a more efficient use of aeration energy. Applying the current state of knowledge about oxygen transfer leads to the conclusion that, in contrast to current opinion, simultaneous aerobic stabilization requires the same SOTR as conventional activated sludge systems with advanced nutrient removal, even though a higher organic load is degraded.


Subject(s)
Cost Savings , Models, Theoretical , Oxygen/chemistry , Sewage/chemistry , Water Purification/economics , Water Purification/methods , Aerobiosis , Biological Oxygen Demand Analysis , Sewage/microbiology , Time Factors , Viscosity
8.
Acta Myol ; 30(1): 4-8, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21842586

ABSTRACT

Neuroinflammation is a pathological hallmark of neurodegenerative diseases including amyotrophic lateral sclerosis (ALS), and is characterized by activated microglia at sites of neuronal injury. In ALS, neurons do not die alone; neuronal injury is noncell-autonomous and depends upon a well-orchestrated dialogue between motor neurons and microglia. Evidence from transgenic models expressing mutant superoxide dismutase 1 (SOD) suggests that the dialogue between motor neurons and microglia initially protects motor neurons. However, with increasing stress and injury within motor neurons, induced by the presence of misfolded proteins such as mSOD1, mitochondrial function and axoplasmic flow are impaired and endoplasmic reticulum stress is induced; misfolded proteins themselves or alternate signals are released from motor neurons and activate microglia. Activated microglia, in turn, switch from anti-inflammatory and neuroprotective to proinflammatory and neurotoxic. Neurotoxic signaling from motor neurons promotes microglial release of reactive oxygen species and pro-inflammatory cytokines further enhancing motor neuron stress and cell injury and initiating a self-propagating cycle of motor neuron injury and cell death. A greater understanding of how to restore the imbalance between neuroprotection and cytotoxicity will depend upon a greater understanding of the motor neuron-microglial dialogue.


Subject(s)
Amyotrophic Lateral Sclerosis/physiopathology , Microglia/physiology , Motor Neurons/physiology , Animals , Cell Communication , Cell Death , Endoplasmic Reticulum/physiology , Humans , Inflammation Mediators/metabolism , Mitochondria, Muscle/physiology , Protein Folding , Reactive Oxygen Species/metabolism , Signal Transduction , Superoxide Dismutase/physiology , Superoxide Dismutase-1
9.
Int J Qual Health Care ; 22(6): 486-92, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20956283

ABSTRACT

OBJECTIVE: The increasing prevalence of obesity requires particularly primary care providers to take action. The aim of this study was to analyze general practitioners (GPs) encounters with overweight and obese patients in primary care to test the hypothesis that patients with a BMI ≥ 30 kg/m² would have longer consultations focusing on lifestyle-related issues like nutrition and physical activity than those with a BMI < 30 kg/m². DESIGN: Cross sectional comparison of audiotaped encounters of patients with a BMI ≥ 30 kg/m² and those with a BMI < 30 kg/m². SETTING: Twelve GP surgeries in Berlin, Germany. PARTICIPANTS: Fifty patients who agreed to have preventive check-up encounters audiotaped. MAIN OUTCOME MEASURES: Based on the Roter Interaction ANALYSIS: System (RIAS) we assessed duration of encounter and the prevalence of GP statements regarding cardiovascular risks, nutrition and physical activity. RESULTS: An increased BMI was found to be a predictor for the length of encounters (P = 0.01), whereas the content of talks was mainly determined by the individual of GP and sex of the GP. Statements regarding cardiovascular risks were most frequent, followed by those regarding nutrition and physical activity. In this study the assessed physiological parameters were not associated with the specific contents of preventive encounters like nutrition or physical activity (P > 0.05). CONCLUSIONS: Our results indicate that GPs rarely use the check-up program to conduct lifestyle consultations with obese patients. Barriers to lifestyle counseling and possible solutions are discussed with a view to promoting individualized and target management of overweight patients.


Subject(s)
Counseling/statistics & numerical data , Health Behavior , Obesity/prevention & control , Overweight/therapy , Primary Health Care/methods , Adult , Berlin , Body Mass Index , Cardiovascular Diseases/etiology , Cardiovascular Diseases/prevention & control , Counseling/methods , Cross-Sectional Studies , Female , Guideline Adherence , Humans , Male , Middle Aged , Motor Activity , Nutritional Sciences/education , Obesity/complications , Obesity/therapy , Office Visits/statistics & numerical data , Overweight/complications , Overweight/prevention & control , Primary Health Care/standards , Risk Factors , Sex Factors
10.
Rozhl Chir ; 89(3): 188-93, 2010 Mar.
Article in Czech | MEDLINE | ID: mdl-20514915

ABSTRACT

AIM: The evaluation of the contribution of Free Hand camera to laparoscopic resection of colon sigmoideum in clinical praxis. MATERIAL AND METHOD: Free Hand camera is an automatic camera system controlled by a surgeon. In the prospective-retrospective trial we have compared two groups of 20 patients together. In the first group there were patients with laparoscopic resection of colon sigmoideum with the Free hand camera usage and in the second group there were patients with laparoscopic resection of colon sigmoideum with a human assistant. We evaluated the length of surgery and surgeon's comfort. The intraoperative data of both of the patient groups were compared with the usage of physiological and operative score (POSSUM). RESULTS: The length of surgery in the group with the human assistant and Free Hand camera were 149, and 161 minutes respectively. There is no statistically significant difference in the length of surgery (p = 0.05) in both of the groups. The surgeon in both of the patient groups evaluated the operative view and comfort as good. CONCLUSION: The pilot study has shown the usability of Free Hand in praxis. The daily usage of Free Hand camera is possible in elective as well as acute surgeries after managing of the learning curve.


Subject(s)
Colon, Sigmoid/surgery , Laparoscopy , Video-Assisted Surgery/instrumentation , Female , Humans , Male , Middle Aged , Robotics
12.
Neurology ; 71(17): 1326-34, 2008 Oct 21.
Article in English | MEDLINE | ID: mdl-18936424

ABSTRACT

BACKGROUND: Amyotrophic lateral sclerosis (ALS), an inexorably progressive motoneuron disease, is accompanied by significantly increased markers of inflammation. These inflammatory constituents could protect, harm, do neither, or do both. OBJECTIVE: Allogeneic hematopoietic stem cell transplantation (HSCT) was performed in patients with sporadic ALS to suppress neuroinflammation and improve clinical outcomes after CNS engraftment. METHODS: Six patients with definite ALS received total body irradiation followed by peripheral blood HSCT infusion from human leukocyte antigen identically matched sibling donors. Disease progression and survival were assessed monthly and compared with matched historic database patients. Autopsy samples from brain and spinal cord were examined immunohistochemically and by quantitative reverse-transcriptase polymerase chain reaction. Donor-derived DNA in brain and spinal cord tissue was evaluated for the extent of chimerism. RESULTS: No clinical benefits were evident. Four patients were 100% engrafted; postmortem tissue examination in two of the 100% engrafted patients demonstrated 16% to 38% donor-derived DNA at sites with motoneuron pathology, which may correspond to the observed increased CD68 or CD1a-positive cells. Neither donor DNA nor increased cell numbers were found in several unaffected brain regions. A third minimally engrafted patient had neither donor DNA nor increased infiltrating cells in the CNS. CONCLUSIONS: This study demonstrates that peripheral cells derived from donor hematopoietic stem cells can enter the human CNS primarily at sites of motoneuron pathology and engraft as immunomodulatory cells. Although unmodified hematopoietic stem cells did not benefit these sporadic amyotrophic lateral sclerosis patients, such cells may provide a cellular vehicle for future CNS gene therapy.


Subject(s)
Amyotrophic Lateral Sclerosis/surgery , Hematopoietic Stem Cell Transplantation/methods , Transplantation Conditioning/methods , Adult , Amyotrophic Lateral Sclerosis/mortality , Amyotrophic Lateral Sclerosis/physiopathology , Humans , Male , Middle Aged , Pilot Projects , Prospective Studies
13.
Neurology ; 62(9): 1611-2, 2004 May 11.
Article in English | MEDLINE | ID: mdl-15136693

ABSTRACT

The presence of oxidative damage and increased iron deposition in CNS tissues of ALS patients prompted the authors to examine the prevalence of two common HFE gene mutations linked to iron accumulation and consequent oxidative stress. The prevalence of the C282Y and H63D mutations was nearly identical in 51 ALS patients and 47 normal control subjects. The presence of either mutation did not significantly affect the age at onset or rate of progression in ALS.


Subject(s)
Amyotrophic Lateral Sclerosis/genetics , Hemochromatosis/genetics , Mutation , Amyotrophic Lateral Sclerosis/diagnosis , Chromosomes, Human, Pair 6/genetics , DNA Mutational Analysis , Female , Gene Frequency , Genetic Predisposition to Disease , Genotype , Hemochromatosis/diagnosis , Heterozygote , Homozygote , Humans , Male , Middle Aged , Mutation/genetics , Oxidative Stress/genetics , Risk Factors
14.
Neurology ; 62(10): 1758-65, 2004 May 25.
Article in English | MEDLINE | ID: mdl-15159474

ABSTRACT

BACKGROUND: Markers of oxidative stress and immune activation are significantly elevated in postmortem ALS CNS tissue, although the relevance to pathogenesis is unclear. OBJECTIVE: To determine the degree and distribution of oxidative stress and immune activation in living ALS patients and whether these levels correlate with the rate of progression or extent of disease. METHOD: Serum and CSF samples from sporadic ALS (sALS) patients were assayed for 4-hydroxy-2,3-nonenal (HNE), a lipid peroxidation product, and monocyte chemoattractant protein-1alpha (MCP-1alpha), a beta-chemokine, by high-performance liquid chromatography and ELISA and compared with levels measured in disease and normal control subjects by one-way analysis of variance. SALS serum levels were analyzed in relation to rate of progression, stage of disease, and drug therapy. RESULTS: HNE levels were significantly elevated in the sera and spinal fluid of sALS patients compared with control populations and positively correlated with extent of disease but not rate of progression. MCP-1alpha levels were also elevated in the sera of sALS patients, with the exception of the neurodegenerative disease control subjects, but decreased with advancing disease. CSF MCP-1alpha levels were not different between the sampled populations. There was no correlation between serum HNE and MCP-1alpha levels in sALS patients and extent of disease. However, an inverse relationship between HNE and MCP-1alpha was demonstrable in vitro. Low levels of HNE stimulated release of MCP-1alpha from cultured human macrophages, whereas high levels inhibited release of MCP-1alpha. CONCLUSIONS: These data confirm the presence of increased oxidative stress and immune activation in ALS patients. HNE is also suggested as a possible biomarker of disease.


Subject(s)
Aldehydes/blood , Amyotrophic Lateral Sclerosis/blood , Chemokine CCL2/blood , Lipid Peroxidation , Adult , Aged , Aldehydes/cerebrospinal fluid , Amyotrophic Lateral Sclerosis/cerebrospinal fluid , Amyotrophic Lateral Sclerosis/immunology , Biomarkers , Chemokine CCL2/metabolism , Disease Progression , Female , Humans , Macrophages/metabolism , Male , Middle Aged , Neurodegenerative Diseases/blood , Neurodegenerative Diseases/cerebrospinal fluid , Oxidative Stress
15.
Neurology ; 62(2): 319-22, 2004 Jan 27.
Article in English | MEDLINE | ID: mdl-14745081

ABSTRACT

Expression of the DNA repair enzyme poly(ADP-ribose) polymerase (PARP) is a known response to oxidative damage of DNA. In ALS brain, PARP expression by western analyses was increased in the motor cortex, parietal cortex, and cerebellum. PARP immunostaining in the motor cortex was increased in ALS neurons and subcortical glia and macrophages. Importantly, there was widespread increased PARP expression in neurons in the parietal cortex and cerebellum, regions that are typically clinically unaffected in ALS, suggesting widespread oxidative stress.


Subject(s)
Amyotrophic Lateral Sclerosis/enzymology , Brain/enzymology , Nerve Tissue Proteins/analysis , Poly(ADP-ribose) Polymerases/analysis , Biomarkers , Cerebellum/enzymology , Enzyme Induction , Humans , Macrophages/enzymology , Middle Aged , Motor Cortex/enzymology , Neuroglia/enzymology , Neurons/enzymology , Oxidative Stress , Parietal Lobe/enzymology
16.
Differentiation ; 67(4-5): 98-106, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11683500

ABSTRACT

The MAPKK Byr1 is an essential component of a Ras-dependent MAPK module required for sexual differentiation in the fission yeast, Schizosaccharomyces pombe. Here we describe the genetic and molecular characterization of a highly conserved protein, Bob1, which was identified from a two-hybrid screen for Byr1-interacting proteins. Byrl and Bobl proteins coprecipitate from S. pombe cell lysates, and both proteins localize to the tips and septa of S. pombe cells. S. pombe bob1 null (bob1delta) mutants lack obvious growth defects but exhibit a significant mating deficiency, which can be suppressed by overexpression of Byrl. Overexpression of Bob1 also leads to inhibition of mating in S. pombe, and this defect is likewise suppressed by Byrl overexpression. Bob1 is highly homologous in structure to the mammalian MM-1/Pfd5 and budding yeast Gim5/Pfd5-Sc proteins, which have been implicated as regulators of actin and tubulins. Similar to budding yeast gim5/pfd5-Sc mutants, S. pombe bob1delta cells have cytoskeletal defects, as judged by hypersensitivity to cytoskeletal disrupting drugs. byr1delta mutants do not share this characteristic with bob1delta mutants, and byr1delta bob1delta mutants are not significantly more sensitive to cytoskeletal disrupting drugs than cells carrying only the bob1delta mutation. Taken together, our results suggest that Bob1 has Byr1-related function(s) required for proper mating response of S. pombe cells and Byrl-independent function(s) required for normal cytoskeletal control. We show that the human MM-1/Pfd5 protein can substitute for its counterpart in fission yeast, providing evidence that the functions of Bob1-related proteins have been highly conserved through evolution. Our results lead us to propose that Bob1-related proteins may play diverse roles in eukaryotic organisms.


Subject(s)
Protein Kinases/metabolism , Repressor Proteins/chemistry , Schizosaccharomyces pombe Proteins/metabolism , Schizosaccharomyces/cytology , Schizosaccharomyces/metabolism , Amino Acid Sequence , Base Sequence , Catalysis , Cell Differentiation , Conserved Sequence , Cytoskeleton/drug effects , Cytoskeleton/metabolism , Humans , Microscopy, Fluorescence , Molecular Sequence Data , Mutation/genetics , Protein Binding , Protein Kinases/genetics , Repressor Proteins/metabolism , Reproduction, Asexual/drug effects , Schizosaccharomyces/enzymology , Schizosaccharomyces/genetics , Schizosaccharomyces pombe Proteins/genetics , Substrate Specificity , Thiabendazole/pharmacology , Two-Hybrid System Techniques
17.
Mol Cell ; 7(5): 1095-101, 2001 May.
Article in English | MEDLINE | ID: mdl-11389855

ABSTRACT

The p21-activated kinase, Shk1, is essential for viability, establishment and maintenance of cell polarity, and proper mating response in the fission yeast, Schizosaccharomyces pombe. Here we describe the characterization of a highly conserved, WD repeat protein, Skb15, which negatively regulates Shk1 in fission yeast. A null mutation in the skb15 gene is lethal and results in deregulation of actin polymerization and localization, microtubule biogenesis, and the cytokinetic machinery, as well as a substantial uncoupling of these processes from the cell cycle. Loss of Skb15 function is suppressed by partial loss of Shk1, demonstrating that negative regulation of Shk1 by Skb15 is required for proper execution of cytoskeletal remodeling and cytokinetic functions. A mouse homolog of Skb15 can substitute for its counterpart in fission yeast, demonstrating that Skb15 protein function has been substantially conserved through evolution.


Subject(s)
Fungal Proteins/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Schizosaccharomyces pombe Proteins , Schizosaccharomyces/chemistry , Actins/drug effects , Animals , Conserved Sequence , Cytoskeleton/drug effects , Evolution, Molecular , Fungal Proteins/genetics , Mice , Microtubules/drug effects , Mutation , p21-Activated Kinases
18.
J Biol Chem ; 276(18): 14549-52, 2001 May 04.
Article in English | MEDLINE | ID: mdl-11278267

ABSTRACT

The p21-activated kinase, Shk1, is required for cell viability, establishment and maintenance of cell polarity, and proper mating response in the fission yeast, Schizosaccharomyces pombe. Previous genetic studies suggested that a presumptive protein methyltransferase, Skb1, functions as a positive modulator of Shk1. However, unlike Shk1, Skb1 is not required for viability or mating of S. pombe cells and contributes only modestly to the regulation of cell morphology under normal growth conditions. Here we demonstrate that Skb1 plays a more significant role in regulating cell growth and polarity under conditions of hyperosmotic stress. We provide evidence that the inability of skb1Delta cells to properly maintain cell polarity in hyperosmotic conditions results from inefficient subcellular targeting of F-actin. We show that Skb1 localizes to cell ends, sites of septation, and nuclei of S. pombe cells. Hyperosmotic shock results in substantial delocalization of Skb1 from cell ends and nuclei, as well as stimulation of Skb1 protein methyltransferase activity. Taken together, our results demonstrate a new role for Skb1 as a mediator of hyperosmotic stress response in fission yeast. We show that the protein methyltransferase activity of the human Skb1 homolog, Skb1Hs, is also stimulated by hyperosmotic stress in fission yeast, providing evidence for evolutionary conservation of a role for Skb1-related proteins as mediators of hyperosmotic stress response, as well as mechanisms involved in regulating this novel class of protein methyltransferases.


Subject(s)
Carrier Proteins/metabolism , Methyltransferases , Schizosaccharomyces pombe Proteins , Schizosaccharomyces/metabolism , Culture Media , Osmotic Pressure
19.
J Clin Neurosci ; 7(4): 312-5, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10938608

ABSTRACT

We recently demonstrated the effectiveness of dorsal foraminotomy in lateral herniated cervical disc after 1 year follow-up in a prospective study.(1) The goal of this paper is to confirm these results concerning long term outcome. We carried out a prospective, consecutive study on 54 patients, operated on for lateral herniated cervical disc. We analysed demographic data, the case history, the neurological examination on admission and imaging data. Ninety per cent were followed up for 3.5 years postoperatively. According to their ratings on a pain scale the group were divided into favourable and unfavourable outcomes. These groups were analysed in relation to the patient's initial condition. At follow up, 90% of patients showed complete recovery or improvement. A long standing preoperative neurological deficit seems to be an important prognostic factor for unfavourable long term outcome after cervical foraminotomy.


Subject(s)
Cervical Vertebrae/surgery , Intervertebral Disc Displacement/surgery , Intervertebral Disc/surgery , Adult , Aged , Cervical Vertebrae/pathology , Cervical Vertebrae/physiopathology , Female , Follow-Up Studies , Humans , Intervertebral Disc/pathology , Intervertebral Disc/physiopathology , Intervertebral Disc Displacement/pathology , Intervertebral Disc Displacement/physiopathology , Male , Middle Aged , Prospective Studies , Recovery of Function , Time Factors , Treatment Outcome
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