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1.
Front Endocrinol (Lausanne) ; 14: 1226808, 2023.
Article in English | MEDLINE | ID: mdl-37664863

ABSTRACT

Non-alcoholic steatohepatitis (NASH) is an aggressive form of fatty liver disease with hepatic inflammation and fibrosis for which there is currently no drug treatment. This study determined whether an indoline derivative, AN1284, which significantly reduced damage in a model of acute liver disease, can reverse steatosis and fibrosis in mice with pre-existing NASH and explore its mechanism of action. The mouse model of dietary-induced NASH reproduces most of the liver pathology seen in human subjects. This was confirmed by RNA-sequencing analysis. The Western diet, given for 4 months, caused steatosis, inflammation, and liver fibrosis. AN1284 (1 mg or 5 mg/kg/day) was administered for the last 2 months of the diet by micro-osmotic-pumps (mps). Both doses significantly decreased hepatic damage, liver weight, hepatic fat content, triglyceride, serum alanine transaminase, and fibrosis. AN1284 (1 mg/kg/day) given by mps or in the drinking fluid significantly reduced fibrosis produced by carbon tetrachloride injections. In human HUH7 hepatoma cells incubated with palmitic acid, AN1284 (2.1 and 6.3 ng/ml), concentrations compatible with those in the liver of mice treated with AN1284, decreased lipid formation by causing nuclear translocation of the aryl hydrocarbon receptor (AhR). AN1284 downregulated fatty acid synthase (FASN) and sterol regulatory element-binding protein 1c (SREBP-1c) and upregulated Acyl-CoA Oxidase 1 and Cytochrome P450-a1, genes involved in lipid metabolism. In conclusion, chronic treatment with AN1284 (1mg/kg/day) reduced pre-existing steatosis and fibrosis through AhR, which affects several contributors to the development of fatty liver disease. Additional pathways are also influenced by AN1284 treatment.


Subject(s)
Non-alcoholic Fatty Liver Disease , Animals , Mice , Humans , Non-alcoholic Fatty Liver Disease/drug therapy , Non-alcoholic Fatty Liver Disease/etiology , Lipogenesis/genetics , Receptors, Aryl Hydrocarbon/genetics , Hepatocytes , Liver Cirrhosis/drug therapy , Liver Cirrhosis/etiology , Inflammation
2.
Med J Malaysia ; 78(3): 296-300, 2023 05.
Article in English | MEDLINE | ID: mdl-37271838

ABSTRACT

INTRODUCTION: Hospital-acquired infection is still one of the health problems in the world that require infection control and prevention efforts, especially nurses' hand washing compliance. Various strategies and efforts to improve handwashing compliance include educational approaches, motivation and improvement of the health care system, one of which is through the use of The Theory Of Planned Behaviour application in solving handwashing compliance. MATERIALS AND METHODS: Quantitative research with a survey approach and observation of hand washing compliance of all nurses N = 321 with a sample of n = 178 nurses. The research variables studied consisted of intention, discipline, self-assessment, opportunity compliance and implementation of the nurse's hand washing. Nurse handwashing compliance observations were made by Infection Prevention Control Link Nurse (IPCN) committee. Data analysis using structural equation modelling (SEM) with smart partial least square (SmartPLS 3.0) application. RESULTS: The nurse's intention to apply the theory of planned behaviour has no significant effect on the implementation of hand washing with path coefficients of 0.104 and p-value 0.221 > 0.05. The effect of nurses' intentions on the implementation of nurse hand washing through discipline is significant with a value of variance accounted for (VAF) 0.8043 or 80.43 % of nurse discipline is a complete mediation variable. CONCLUSION: Discipline as a complete meditation variable in the application of the theory of planned behaviour in the compliance of nurses' hand washing five moments six steps. Nurses are expected to continuously improve their discipline independently or be assisted by training activities facilitated by the hospital.


Subject(s)
Cross Infection , Hand Disinfection , Humans , Cross Infection/prevention & control , Infection Control , Intention , Surveys and Questionnaires
3.
Nat Prod Res ; : 1-6, 2023 Mar 20.
Article in English | MEDLINE | ID: mdl-36938907

ABSTRACT

In our continuation of exploring antidiabetic agents from Garcinia species, we found that the methanolic extract of G. macrantha A.C.Sm. exhibited considerable α-glucosidase inhibition of 58.20 ± 0.37% in sucrose substrate and 39.86 ± 2.07% in maltose substrate at 100 µg/mL. Phytochemical investigation on the extract revealed the presence of a new biphenyl, macrabiphenyl A, which was successfully elucidated by means of spectroscopic methods (HRESIMS and 1D and 2D NMR). The α-glucosidase inhibitory evaluation indicated that the new compound was weakly active against the enzyme.

4.
Cureus ; 15(1): e33767, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36655153

ABSTRACT

Background Antibiotics significantly increased life expectancy and decreased mortality rates due to infections. However, this trend is starting to fade with the rise of multidrug-resistant organisms (MDR); these strains are becoming a global burden on healthcare and the economy. The dramatic increase and spread of carbapenem-resistant gram-negative bacteria (CRGNB) has become a serious global public health concern. In this retrospective cross-sectional study, we aimed to estimate the rates of gram-negative bacteremia in five tertiary care hospitals in different geographical locations in Saudi Arabia for five years. Methods A retrospective cross-sectional study was conducted in five tertiary care hospitals in Saudi Arabia among patients with bacteremia due to CRGNB. Electronic medical records were used to retrieve data regarding patient demographics and antimicrobial susceptibility testing (AST) over five years between January 2016 and December 2020. Patients with positive blood cultures for carbapenem-resistant Escherichia (E.) coli, Klebsiella (K.) pneumonia, Pseudomonas (P.) aeruginosa, and Acinetobacter (A.) baumannii comprise the final study population. Results This retrospective multicentric study was conducted between 2016 and 2020 in five tertiary care hospitals across five cities in Saudi Arabia. E. coli (n=2190, 38.03%), K. pneumoniae (n=2154, 37.41%), P. aeruginosa (n = 918, 15.94%), and A. baumannii (n=496, 8.61%) constitute the 5758 gram-negative bacteria isolates. E. coli was the most frequently identified species in Riyadh, AlAhsa, Dammam, and Madinah (40%, 46.50%, 61.67%, and 43.66%, respectively), with a p-value of (p<0.001), except in Jeddah, where K. pneumoniae was the most prevalent (42%). The mean age of patients across Riyadh, AlAhsa, Dammam, and Madinah was 62.2 years (± 4.24). In contrast to Jeddah, where the majority of isolates (702; 41.8%) belonged to the adult age group. Most isolates were from male patients (3045; 52.9%), compared to 2713 (47.1%) from female patients. K. pneumoniae 1226 (40.3%) was the most prevalent isolate among male patients while E. coli (1135; 41.8%) was the most prevalent isolate among female patients. Conclusion Our study showed that the prevalence of carbapenem non-susceptible Gram-negative bacteria is relatively high, which therefore makes them very challenging to treat. The results show an urgent need for improved antibiotic stewardship strategies, including better surveillance and more effective infection control measures to reduce this issue. Further research into the molecular epidemiology and risk factors associated with these infections is necessary to guide public health policymakers in developing interventions to help control the spread of carbapenem-resistant Gram-negative bacteria.

5.
J Psychosom Res ; 129: 109909, 2020 02.
Article in English | MEDLINE | ID: mdl-31901581

ABSTRACT

OBJECTIVE: The Syrian war created a mass exodus of people to neighboring countries. Jordan hosts approximately 1.4 million Syrians who sought refuge and protection. This research represents an effort to understand the subjective narratives of Syrian refugee women's war traumatic experiences and displacement challenges while living in Jordan and the consequences on their physical and mental health. METHODS: Data gathered between March and June 2014 included 24 in-depth interviews with Syrian refugee women who sought services from humanitarian organizations in Jordan. Interviews were conducted in Arabic and were audio recorded. A team of four researchers translated and transcribed the interviews. Group narrative methodology was utilized to analyze the interviews. RESULTS: The study suggests that Syrian refugee women experienced diverse war atrocities including shelling, loss of property, separation from family members, and threats to their lives and their beloved ones, among a few. In Jordan, they reported on multiple displacement challenges, which are perceived as a continuous traumatic experience, as well as somatization. Narratives of women also included sequelae to their physical and mental health due to such stressors. Barriers to obtaining physical and mental health services are discussed, including inadequate medical treatment, lack of mental health services, and stigma on mental health, which might be associated to somatization of mental illnesses. CONCLUSION: It is crucial that humanitarian organizations and host countries like Jordan bear the responsibility to enhancing accessibility to comprehensive trauma-focused physical and mental health services for Syrian refugees in a culturally and gender sensitive manner.


Subject(s)
Mental Disorders/psychology , Prisoners of War/psychology , Violence/psychology , Adult , Female , Humans , Middle Aged , Refugees/psychology , Syria , Young Adult
6.
Article in English | WPRIM (Western Pacific) | ID: wpr-780814

ABSTRACT

@#Chyle leak is a well-known complication that can occur after a thyroidectomy with neck dissection; however, it rarely occurs after thyroidectomy alone. Here, we report a case of chyle leak following a left hemithyroidectomy for a benign solitary thyroid nodule. Based on the literature search, this is only the second reported case of a chyle leak after a simple hemithyroidectomy without any central or lateral neck dissection. Amongst the possible causes, we hypothesize that the use of intraoperative nerve monitor may be a contributing factor. Treatment options are explored and the patient was treated successfully with nonoperative management.

7.
Chemosphere ; 108: 159-67, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24698170

ABSTRACT

Concentrations of 28 trace elements (Li, Mg, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Tl, Hg, Pb, and Bi) in the livers of juvenile and adult American alligators inhabiting two central Florida lakes, Lake Apopka (LA), and Lake Woodruff National Wildlife Refuge (LW) and one lagoon population located in Merritt Island National Wildlife Refuge (MINWR; NASA), were determined. In juveniles from MINWR, concentrations of nine elements (Li, Fe, Ni, Sr, In, Sb, Hg, Pb and Bi) were significantly higher, whereas six elements (V, Fe, As, Sr, Hg and Bi) were elevated in adults (p<0.05) obtained from MINWR. Significant enrichment of some trace elements in adults, relative to juveniles, was observed at all three sampling areas. Specifically, Fe, Pb and Hg were significantly elevated in adults when compared to juveniles, suggesting age-dependent accumulation of these elements. Further, As, Se and Sn showed the same trend but only in animals collected from MINWR. Mean Fe concentrations in the livers of adults from LA, LW and MINWR were 1770 µg g(-1) DW, 3690 µg g(-1) DW and 5250 µg g(-1) DW, respectively. More than half of the adult specimens from LW and MINWR exhibited elevated hepatic Fe concentrations that exceed the threshold value for toxic effects in donkey, red deer and human. These results prompted us to express our concern on possible exposure and health effects in American alligators by some trace elements derived from NASA activities.


Subject(s)
Liver/chemistry , Trace Elements/analysis , Water Pollutants, Chemical/chemistry , Alligators and Crocodiles/growth & development , Animals , Female , Florida , Iron/analysis , Lakes , Male , Mass Spectrometry , Water Pollutants, Chemical/analysis
8.
Chemosphere ; 93(8): 1500-10, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24054131

ABSTRACT

We investigated the PCBs, PBDEs and HBCDs contamination in sludge, sediments and fish from various locations including raw leachate pond, leachate treatment plans (LTPs), control wells and reference site at open landfill of municipal dumpsite, Surabaya City, Indonesia. 62 PCBs and 14 PBDEs congeners, and 3 HBCDs isomers were identified and quantified using GC-MS and LC-MS/MS, respectively. Concentration ranges and median (value in parentheses) of PCBs, PBDEs and HBCDs were from not detected (ND) to 60 (3.9) ng g(-1) dw, 0.0075 to 45 (4.5) ng g(-1) dw and ND to 2.8 (0.052) ng g(-1) dw in sludge and sediments, respectively. While in two polled of fish samples were 30-55 ng g(-1) lw, 6.6-11 ng g(-1) lw and 1.6-3.3 ng g(-1) lw, respectively. Among the sampling sites, the highest level of PCBs and PBDEs were detected in sludge from raw leachate pond. However, PCBs and PBDEs levels were showing decreased in LTP-1 that could be due to the bacterial degradation but not in LTP-2, HBCDs were more stable in both LTPs. Levels of PCBs and BFRs in sludge at the present study were lower than those reported in sewage sludge reported from some other countries. PCBs profiles were mainly composed in that order by CB-138, -153, -180, -101, -118 and -28, while by BDE-47, -99, -100, -153, -154 and -28 for PBDEs in sludge, sediments and fish. Profiles of HBCDs were predominantly composed by γ- and α-isomers in sludge and fish, respectively. Debromination, dechlorination, commercial formulations used and congener-specific accumulation of those contaminants are the factors influenced the profiles.


Subject(s)
Fishes/metabolism , Flame Retardants/analysis , Polychlorinated Biphenyls/analysis , Waste Disposal Facilities , Water Pollutants, Chemical/analysis , Animals , Flame Retardants/metabolism , Indonesia , Polychlorinated Biphenyls/metabolism , Water Pollutants, Chemical/metabolism
9.
Am J Transplant ; 13(8): 2207-10, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23763601

ABSTRACT

Islet transplantation after successful kidney transplantation is a recognized treatment for adults with diabetes and end-stage renal disease (ESRD), but has not been considered an option in the pediatric population. To our knowledge, we report the first combined islet and kidney transplant in a child. The patient was born with bilateral renal hypoplasia and was diagnosed with type 1 diabetes mellitus at age 13 months. He had erratic glycemic control and hypoglycemia unawareness. At 6 years of age, the child safely underwent simultaneous islet and live donor kidney transplantation. Although function of the islet graft was transient, the combined transplant provided significant benefits in terms of glucose control and overall growth and development. Such an approach represents a viable treatment option for pediatric patients with ESRD and unstable diabetes.


Subject(s)
Blood Glucose/analysis , Diabetes Mellitus, Type 1/surgery , Kidney Failure, Chronic/surgery , Kidney Transplantation , Pancreas Transplantation , Adult , Child , Diabetes Mellitus, Type 1/complications , Female , Humans , Kidney Failure, Chronic/complications , Male , Prognosis
10.
Diabetologia ; 56(2): 391-400, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23086558

ABSTRACT

AIMS/HYPOTHESIS: Type 1 diabetes results from a chronic autoimmune process continuing for years after presentation. We tested whether treatment with teplizumab (a Fc receptor non-binding anti-CD3 monoclonal antibody), after the new-onset period, affects the decline in C-peptide production in individuals with type 1 diabetes. METHODS: In a randomised placebo-controlled trial we treated 58 participants with type 1 diabetes for 4-12 months with teplizumab or placebo at four academic centres in the USA. A central randomisation centre used computer generated tables to allocate treatments. Investigators, patients, and caregivers were blinded to group assignment. The primary outcome was a comparison of C-peptide responses to a mixed meal after 1 year. We explored modification of treatment effects in subgroups of patients. RESULTS: Thirty-four and 29 subjects were randomized to the drug and placebo treated groups, respectively. Thirty-one and 27, respectively, were analysed. Although the primary outcome analysis showed a 21.7% higher C-peptide response in the teplizumab-treated group (0.45 vs 0.371; difference, 0.059 [95% CI 0.006, 0.115] nmol/l) (p = 0.03), when corrected for baseline imbalances in HbA(1c) levels, the C-peptide levels in the teplizumab-treated group were 17.7% higher (0.44 vs 0.378; difference, 0.049 [95% CI 0, 0.108] nmol/l, p = 0.09). A greater proportion of placebo-treated participants lost detectable C-peptide responses at 12 months (p = 0.03). The teplizumab group required less exogenous insulin (p < 0.001) but treatment differences in HbA(1c) levels were not observed. Teplizumab was well tolerated. A subgroup analysis showed that treatment benefits were larger in younger individuals and those with HbA(1c) <6.5% at entry. Clinical responders to teplizumab had an increase in circulating CD8 central memory cells 2 months after enrolment compared with non-responders. CONCLUSIONS/INTERPRETATIONS: This study suggests that deterioration in insulin secretion may be affected by immune therapy with teplizumab after the new-onset period but the magnitude of the effect is less than during the new-onset period. Our studies identify characteristics of patients most likely to respond to this immune therapy. TRIAL REGISTRATION: ClinicalTrials.gov NCT00378508 FUNDING: This work was supported by grants 2007-502, 2007-1059 and 2006-351 from the JDRF and grants R01 DK057846, P30 DK20495, UL1 RR024139, UL1RR025780, UL1 RR024131 and UL1 RR024134 from the NIH.


Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , C-Peptide/metabolism , Diabetes Mellitus, Type 1/drug therapy , Adolescent , Diabetes Mellitus, Type 1/metabolism , Female , Glycated Hemoglobin/metabolism , Humans , Insulin/metabolism , Male
11.
Arch Oral Biol ; 51(7): 558-66, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16405863

ABSTRACT

UNLABELLED: Sjögren's syndrome (SS) is a systemic autoimmune disease which targets the exocrine glands and is associated with autoantibodies. The mechanism of salivary gland destruction or autoantibody production is poorly understood but it is increasingly accepted that apoptosis plays a role. OBJECTIVE: The objective of this study is to demonstrate the presence of cleaved alpha-fodrin autoantigen and apoptosis in the salivary glands of patients with primary Sjögren's syndrome. METHODS: 18 patients with primary Sjögren's syndrome provided tissues from a labial salivary gland biopsy. Using terminal deoxynucleotidyl transferase mediated dUTP nick end labelling (TUNEL) assays to detect DNA fragmentation followed by sequential immunoperoxidase assays in the same patient biopsy to detect cleaved alpha-fodrin, Poly(ADP-ribose) polymerase (PARP), and caspase-3, we show a co-localisation between apoptotic markers and disease. RESULTS: Co-localisation of cleaved alpha-fodrin, PARP and caspase-3 expression was demonstrated primarily in the ducts along with DNA fragmentation in 16/18 salivary gland biopsies from Sjögren's syndrome patients. None of these apoptotic markers was strongly expressed in healthy tissues. CONCLUSION: Apoptotic signals may provide useful therapeutic targets and cleaved alpha-fodrin may prove to be a marker of disease in primary Sjögren's syndrome. Further studies are required to ascertain the specific association of cleaved alpha-fodrin with primary and secondary Sjögren's syndrome.


Subject(s)
Autoantigens/analysis , Carrier Proteins/immunology , Caspase 3/analysis , Microfilament Proteins/immunology , Poly Adenosine Diphosphate Ribose/analysis , Salivary Glands/immunology , Sjogren's Syndrome/immunology , Adult , Aged , Apoptosis/immunology , Carrier Proteins/analysis , DNA Fragmentation , Female , Humans , Lip/metabolism , Male , Microfilament Proteins/analysis , Middle Aged , Salivary Glands/chemistry
12.
J Clin Periodontol ; 29(5): 440-7, 2002 May.
Article in English | MEDLINE | ID: mdl-12060427

ABSTRACT

BACKGROUND: Although fibronectin (FN) is an important extracellular glycoprotein involved in periodontal wound healing, it is not clear whether the application of exogenous fibronectin (ExoFN) offers any clinical benefit. The purpose of this preliminary in vitro study was to determine the binding of FN from three different sources, viz. endogenous EDTA-plasma, endogenous serum and exogenous commercial purified human fibronectin in PBS buffer, to demineralized and non-demineralized root powder. METHOD: The binding of FN to a known quantity of mineralized and non-demineralized root powder by overnight incubation at 15 degrees C was studied by enzyme immunoassay (EIA) technique. The criteria for optimal performance of EIA procedure for the determination of FN was established. Particle size of powdered root structure was standardized using a Vibratory Sieve Shaker. RESULTS: The EDTA-plasma and the serum FN exhibited binding of (17.8 +/- 2.1 microg) and (6.5 +/- 4.5 microg), respectively, to the non-demineralized root powder. However, the binding was only significant for the EDTA-plasma FN (p < 0.01) when compared to controls. In the demineralized group there was no ascertainable binding of FN from either endogenous or exogenous sources. ExoFN in buffer exhibited no binding at all to the non-demineralized or demineralized root powder. CONCLUSION: The preliminary data suggest that additional plasma and serum factors may facilitate the binding of FN to root powder. High levels of FN in blood do not necessarily indicate that FN is available for binding to the root surface during periodontal surgery.


Subject(s)
Fibronectins/pharmacology , Periodontium/drug effects , Analysis of Variance , Chelating Agents/chemistry , Decalcification Technique , Dental Cementum/drug effects , Dentin/drug effects , Edetic Acid/chemistry , Fibronectins/blood , Fibronectins/chemical synthesis , Fibronectins/chemistry , Humans , Particle Size , Protein Binding , Regeneration/drug effects , Reproducibility of Results , Spectrophotometry , Temperature , Tooth Root/drug effects
13.
Endocrinology ; 142(1): 498-501, 2001 Jan.
Article in English | MEDLINE | ID: mdl-11145615

ABSTRACT

The phosphoinositide 3-kinase (PI3K) inhibitors, LY294002 (LY) and wortmannin (WM), are widely used to examine the role of PI3K in growth factor signaling. These compounds inhibit the kinase action of PI3K, thus preventing the accumulation of PI(3,4,5)P3 and PI(3,4)P2 (PIs) and subsequent phosphorylation and activation of the downstream effectors of PI3K, Akt and p70(S6K). The efficacy of these inhibitors has been demonstrated by measuring cellular levels of PIs or the kinase activity of immunoprecipitated PI3K. However, their effects on activation of Akt and p70(S6K), more widely used markers of PI3K activation, has not been formally tested. We have examined the effects of LY and WM on phosphorylation of Akt and p70(S6K) by insulin-like growth factor-I, insulin, and platelet-derived growth factor in skeletal muscle cells. LY is much less effective in blocking the phosphorylation of Akt than p70(S6K); at concentrations which completely inhibit phosphorylation of p70(S6K), phosphorylation of Akt is only partially inhibited by LY. WM also inhibits IGF-I-stimulated phosphorylation of Akt and p70(S6K) with unequal potency but is equally effective in blocking insulin-stimulated phosphorylation of these peptides. Our data demonstrate that inhibiting PI3K signaling through one of its downstream mediators (p70(S6K)) may not indicate complete blockage of the PI3K pathway which may be signaling through an alternate downstream branch (Akt). These findings indicate that the efficacy of LY and WM in blocking PI3K-activation of Akt and p70(S6K) must be tested within the context of every experiment, and that the results obtained with the use of these inhibitors must be interpreted according to their specific effects on the PI3K/Akt and PI3K/p70(S6K) signaling pathways.


Subject(s)
Androstadienes/pharmacology , Chromones/pharmacology , Enzyme Inhibitors/pharmacology , Growth Substances/pharmacology , Morpholines/pharmacology , Protein Serine-Threonine Kinases , Proto-Oncogene Proteins/metabolism , Ribosomal Protein S6 Kinases/metabolism , Animals , Cell Line , Insulin/pharmacology , Insulin-Like Growth Factor I/pharmacology , Mice , Muscle, Skeletal , Phosphatidylinositol 3-Kinases/metabolism , Phosphoinositide-3 Kinase Inhibitors , Phosphorylation , Platelet-Derived Growth Factor/pharmacology , Proto-Oncogene Proteins c-akt , Rats , Wortmannin
14.
J Endocrinol ; 167(1): 175-82, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11018765

ABSTRACT

Skeletal myoblasts are inherently programmed to leave the cell cycle and begin the differentiation process following removal of exogenous growth factors. Serum withdrawal results in a marked induction of IGF production which is essential for skeletal muscle differentiation in vitro. However, the potential role of the tyrosine kinase IGF-I receptor (thought to be the principal mediator of both IGF-I and II signaling in skeletal muscle) in the decision of myoblasts to begin differentiation following serum withdrawal is unknown. To explore the role of the IGF-I receptor in this decision by skeletal myoblasts, we functionally inactivated endogenous IGF-I receptors in mouse C2C12 cells using a dominant negative, kinase-inactive IGF-I receptor in which the ATP-binding site lysine (K) at residue 1003 has been mutated to alanine (A). Cell lines with the greatest degree of mutant IGF-I receptor expression (A/K cells) demonstrated functional inactivation of endogenous IGF-I receptors as determined by their impaired ability to phosphorylate the principal substrate of the IGF-I receptor, IRS-1, in response to treatment with IGF-I. In addition, the proliferative response of myoblasts to IGF-I was completely abolished in A/K cells. Following withdrawal of exogenous growth factors, A/K cells demonstrated a marked delay in the induction of the gene expression of myogenin, a skeletal muscle-specific transcription factor essential for differentiation, and a subsequent delay in the induction of muscle creatine kinase activity. Delayed differentiation in A/K cells was associated with prolonged phosphorylation of the cell cycle regulatory retinoblastoma (Rb) protein; it is the un- (or hypo-) phosphorylated form of Rb which is known to promote differentiation in skeletal myoblasts. Thus, the IGF-I receptor regulates the timing of myoblast differentiation induced by serum withdrawal. The delayed differentiation of skeletal myoblasts with functionally inactive IGF-I receptors may result, at least in part, from delayed induction of myogenin gene expression and prolonged phosphorylation of the Rb protein.


Subject(s)
Muscle, Skeletal/cytology , Receptor, IGF Type 1/physiology , Animals , Cell Culture Techniques , Cell Differentiation/physiology , Cell Division/physiology , Culture Media, Serum-Free , Mice , Phosphorylation , Retinoblastoma Protein/metabolism , Transfection
16.
J Cell Biochem ; 78(4): 617-26, 2000 Jun 12.
Article in English | MEDLINE | ID: mdl-10861859

ABSTRACT

Insulinlike growth factors (IGFs) stimulate skeletal muscle cell differentiation in association with an increase in the mRNA of myogenin, a member of the MyoD family of skeletal muscle-specific transcription factors that plays an essential role in the differentiation process. However, this is a relatively late effect, requiring treatment periods of >24 h. In contrast, IGFs initially inhibit skeletal muscle cell differentiation, associated with a marked reduction in myogenin mRNA. The mechanisms by which IGF-I initially inhibits and subsequently stimulates myogenin expression are unknown. In the first 24 h, we find that IGF-I inhibits myogenin gene transcription by >80% but has no effect on myogenin mRNA stability. Similarly, in the first 24 h, IGF-I markedly inhibits myogenin promoter activity; the sequence -145 to -9 of the myogenin gene is sufficient to confer this inhibitory effect of IGF-I. In contrast, 48 h of treatment with IGF-I results in an increase in myogenin promoter activity that parallels the increase in myogenin steady-state mRNA. This increase in promoter activity is completely prevented in constructs lacking the sequence -1,565 to -375 of the myogenin gene. These data indicate that the early inhibitory and late stimulatory effects of IGF-I on myogenin expression are mediated at the level of transcription, and that these time-dependent, opposing effects of IGF-I on myogenin transcription are mediated by distinct regions of the myogenin gene. To our knowledge, this is the first demonstration of a gene whose promoter activity is initially inhibited and subsequently stimulated by IGF-I.


Subject(s)
Gene Expression Regulation , Insulin-Like Growth Factor I/pharmacology , Myogenin/genetics , Myogenin/metabolism , Transcription, Genetic/drug effects , Animals , Blotting, Northern , Cell Differentiation , Cell Line , Cell Nucleus/metabolism , Dactinomycin/pharmacology , Gene Deletion , Muscle, Skeletal/cytology , Nucleic Acid Synthesis Inhibitors/pharmacology , Phosphorylation , Plasmids/metabolism , Promoter Regions, Genetic , RNA, Messenger/metabolism , Rats , Time Factors , Transfection
17.
Orv Hetil ; 136(18): 945-8, 1995 Apr 30.
Article in Hungarian | MEDLINE | ID: mdl-7739854

ABSTRACT

The authors describe the combined occurrence of heparin-induced thrombocytopenia and cumarin-induced skin necrosis, a rare condition that has not yet been reported in Hungary. The 69-year-old woman had received prophylactic heparin treatment prior to total hip arthroplasty. The first complication that the anticoagulant therapy brought about was serious thrombocytopenia paradoxically associated not with bleeding but with deep vein thrombosis. The latter necessitated coumarin therapy which resulted in severe skin necrosis.


Subject(s)
Acenocoumarol/adverse effects , Heparin/adverse effects , Hip Prosthesis , Skin/drug effects , Thrombocytopenia/chemically induced , Thrombophlebitis/etiology , Acenocoumarol/administration & dosage , Aged , Female , Heparin/administration & dosage , Humans , Necrosis/chemically induced , Postoperative Complications/prevention & control , Preoperative Care , Skin/pathology , Thrombocytopenia/complications , Thrombophlebitis/drug therapy
18.
Am J Physiol ; 263(2 Pt 1): E301-9, 1992 Aug.
Article in English | MEDLINE | ID: mdl-1514611

ABSTRACT

To determine the role of cytokines in mediating the decrease in ketones associated with infection, we studied the effect of endotoxin (LPS), interleukin-1 (IL-1), and tumor necrosis factor (TNF) on serum and hepatic ketone body levels (KB), serum free fatty acids (FFA), and hepatic malonyl-CoA levels. LPS decreased serum and hepatic KB in C57Bl/6 (LPS sensitive) mice, whereas it had little effect in C3H/HeJ (LPS resistant) mice, whose macrophages lack the ability to produce IL-1 and TNF in response to LPS, suggesting that IL-1 and TNF may mediate this effect. IL-1 and TNF decreased serum KB in both strains of mice. As seen with LPS, IL-1 decreased hepatic KB, whereas TNF had no such effect. LPS, IL-1, and TNF increased hepatic malonyl-CoA levels. TNF acutely raised serum FFA, whereas LPS and IL-1 did not. Postulating that the TNF-induced increase in FFA overrides the inhibitory effect of malonyl-CoA on fatty acid oxidation and ketogenesis, we used R-2-phenylisopropyladenosine to block TNF-induced lipolysis and demonstrated that in the absence of increased fatty acid flux, TNF inhibits KB formation. As seen with LPS, IL-1, but not TNF, decreased KB in the fasting state. These data suggest that IL-1 and TNF may mediate the antiketogenic effect of infection and that IL-1 has properties closest to that of LPS.


Subject(s)
Interleukin-1/pharmacology , Ketone Bodies/biosynthesis , Tumor Necrosis Factor-alpha/pharmacology , Animals , Drug Resistance/genetics , Endotoxins/pharmacology , Escherichia coli , Fatty Acids, Nonesterified/blood , Ketone Bodies/antagonists & inhibitors , Ketone Bodies/metabolism , Liver/metabolism , Male , Mice , Mice, Inbred C3H , Mice, Inbred C57BL
19.
J Clin Invest ; 89(5): 1603-9, 1992 May.
Article in English | MEDLINE | ID: mdl-1569198

ABSTRACT

To examine the role of cytokines in mediating the lipogenic effects of endotoxin (LPS), we studied the effects of LPS and cytokines on hepatic fatty acid synthesis in LPS-sensitive C3H/OuJ mice and in LPS-resistant C3H/HeJ mice, whose macrophages are defective in the ability to produce tumor necrosis factor (TNF) and IL-1 in response to LPS. HeJ mice were 16-fold less sensitive than OuJ mice to the lipogenic effect of LPS. In OuJ mice, 10 micrograms of LPS caused a maximal increase in hepatic lipogenesis (3.86 +/- 0.41-fold), whereas in HeJ mice the maximal increase was only 1.79 +/- 0.32-fold after 100 micrograms of LPS. This lipogenic response paralleled the decreased ability of LPS to increase hepatic and splenic levels of mRNAs for TNF and IL-1 and serum levels of TNF in HeJ mice. In contrast, the maximal effect of TNF on lipogenesis was greater and the sensitivity to TNF was increased 2.4-fold in HeJ mice compared to OuJ mice. Administration of IFN-gamma before LPS in HeJ mice had no effect on IL-1 mRNA, but partially restored the LPS-induced increase in hepatic and splenic mRNA for TNF and serum TNF levels, which may account for the partial restoration of sensitivity to the lipogenic effect of LPS after IFN-gamma treatment. These results indicate that cytokines produced by mononuclear leukocytes mediate the lipogenic effects of LPS.


Subject(s)
Endotoxins/pharmacology , Interferon-gamma/pharmacology , Monokines/physiology , Animals , Fatty Acids/biosynthesis , Gene Expression , Interleukin-1/genetics , Liver/metabolism , Mice , Mice, Inbred C3H , RNA, Messenger/genetics , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolism
20.
Endocrinology ; 129(3): 1167-74, 1991 Sep.
Article in English | MEDLINE | ID: mdl-1874163

ABSTRACT

The study was carried out to examine the direct effect of the sex hormones 17 beta-estradiol (E2) and testosterone on the modeling of cultured fetal mouse long bones separated according to their sex. The culture system used allowed for the simultaneous assessment of bone growth, mineralization, and resorption on each bone. Bones from 16-day-old male and female mouse fetuses were cultured in BGJ medium, supplemented with either 10% fetal calf serum or 4 mg/ml BSA (serum-free medium) for 48 h. The bones were harvested, and their length; the length of their diaphyses; their hydroxyproline, calcium, and phosphorus contents; and their 45Ca release were measured. Histomorphometric analyses on midlongitudinal sections of bones from parallel experiments were also performed. The results indicate that in medium supplemented with 10% fetal calf serum, E2 had a dose-dependent stimulatory effect on bone formation and mineralization at 10(-7) and 10(-9) M, with no effect on bone resorption. This effect was specific to bones from female mice and to E2, since 17-alpha-estradiol had no effect. Testosterone had similar effects specific to bones from male mice, resulting in the stimulation of bone formation and mineralization at 10(-7)- and 10(-9)-M concentrations. These effects were absent when serum-free medium was used. E2 and testosterone had an anabolic effect on endochondral and periosteal bone formation and mineralization, but no effect on bone resorption. This effect is dependent on the presence of a serum factor(s).


Subject(s)
Bone Resorption , Calcification, Physiologic , Estradiol/pharmacology , Osteogenesis , Testosterone/pharmacology , Animals , Calcification, Physiologic/drug effects , Calcium/analysis , Female , Fetus , Hydroxyproline/analysis , Kinetics , Male , Mice , Mice, Inbred Strains , Organ Culture Techniques , Osteogenesis/drug effects , Phosphorus/analysis , Radius/drug effects , Radius/embryology , Sex Characteristics , Ulna/drug effects , Ulna/embryology
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