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1.
PLoS One ; 17(10): e0273184, 2022.
Article in English | MEDLINE | ID: mdl-36256644

ABSTRACT

BACKGROUND: Ruminant livestock are a major contributor to Australian agricultural sector carbon emissions. Variation in methane (CH4) produced from enteric microbial fermentation of feed in the reticulo-rumen of sheep differs with different digestive functions. METHOD: We isolated rumen epithelium enzymatically to extract membrane and cytosol proteins from sheep with high (H) and low (L) CH4 emission. Protein abundance was quantified using SWATH-mass spectrometry. RESULTS: The research found differences related to the metabolism of glucose, lactate and processes of cell defence against microbes in sheep from each phenotype. Enzymes in the methylglyoxal pathway, a side path of glycolysis, resulting in D-lactate production, differed in abundance. In the H CH4 rumen epithelium the enzyme hydroxyacylglutathione hydrolase (HAGH) was 2.56 fold higher in abundance, whereas in the L CH4 epithelium lactate dehydrogenase D (LDHD) was 1.93 fold higher. Malic enzyme 1 which converts D-lactate to pyruvate via the tricarboxylic cycle was 1.57 fold higher in the L CH4 phenotype. Other proteins that are known to regulate cell defence against microbes had differential abundance in the epithelium of each phenotype. CONCLUSION: Differences in the abundance of enzymes involved in the metabolism of glucose were associated with H and L CH4 phenotype sheep. Potentially this represents an opportunity to use protein markers in the rumen epithelium to select low CH4 emitting sheep.


Subject(s)
Membrane Proteins , Rumen , Sheep , Animals , Rumen/metabolism , Cytosol/metabolism , Membrane Proteins/metabolism , Pyruvaldehyde/metabolism , Australia , Methane/metabolism , Fermentation , Ruminants/metabolism , Epithelium/metabolism , Phenotype , Lactates/metabolism , Glucose/metabolism , Carbon/metabolism , Pyruvates/metabolism , Lactate Dehydrogenases , Diet/veterinary
2.
Osteoarthritis Cartilage ; 26(10): 1326-1332, 2018 10.
Article in English | MEDLINE | ID: mdl-29981835

ABSTRACT

OBJECTIVE: To report the prevalence of varus thrust and normative values for hip-knee-ankle (HKA) angle deviation across the lifespan, and to explore associations between HKA angle deviation and selected clinical factors. DESIGN: This was a cross-sectional observational study of 572 participants from the 1000 Norms Project, aged 3-101 years and who self-reported as being healthy. Video recordings (2D) of frontal plane gait were reviewed by physiotherapists for presence of knee thrust and quantification of HKA angle deviation (the difference between HKA angle at initial contact and mid-stance). Age and sex-stratified normative HKA angle deviation values were presented as means and 95% confidence intervals (CIs). Correlations were calculated between HKA angle and clinical measures (age, sex, body mass index (BMI), alignment, knee and hip strength, Knee Injury and Osteoarthritis Outcomes Scores (KOOS), foot posture index, temporo-spatial gait, and hypermobility). RESULTS: Overall, 31% of the cohort had varus thrust, most prevalent among adults older than 60 years (42%) and children aged 3-9 (41%). Varus thrust was common in adolescents (25%) and adults aged 20-59 (23%). Mean HKA angle deviation for the entire cohort was 1.2° (95%CI: 1.07, 1.36) towards varus, and 2.1° (95%CI: 1.84, 2.36) among people with clinical varus thrust. Weak associations were identified between HKA angle deviation and BMI, stride width, and KOOS-Sports among adolescents, and in adults weakly associated with height. CONCLUSIONS: Prevalence of varus thrust is common across the lifespan. Normative values established here can be readily used by clinicians and researchers in monitoring this gait deviation.


Subject(s)
Bone Malalignment/etiology , Knee Joint/physiopathology , Longevity , Osteoarthritis, Knee/complications , Adolescent , Adult , Aged , Aged, 80 and over , Biomechanical Phenomena , Bone Malalignment/epidemiology , Bone Malalignment/physiopathology , Child , Child, Preschool , Cross-Sectional Studies , Female , Gait/physiology , Humans , Incidence , Knee Joint/diagnostic imaging , Male , Middle Aged , New South Wales/epidemiology , Osteoarthritis, Knee/diagnosis , Osteoarthritis, Knee/physiopathology , Radiography , Reference Values , Retrospective Studies , Video Recording , Young Adult
3.
Osteoarthritis Cartilage ; 25(8): 1282-1290, 2017 08.
Article in English | MEDLINE | ID: mdl-28323136

ABSTRACT

OBJECTIVE: To develop normative reference data for the Knee injury and Osteoarthritis Outcome Score (KOOS) and KOOS-Child, as well as investigate socio-demographic, psychological and physical factors associated with knee pain and disability among healthy adults. METHOD: The KOOS or KOOS-Child (each containing five subscales) was administered to participants aged 8-101 years within the 1000 Norms Project, an observational study of 1000 self-reported healthy individuals. Self-efficacy, physical activity, body mass index (BMI), lower limb alignment, knee frontal plane projection angle (FPPA), knee range of motion (ROM), knee and hip strength, six-minute walk, 30-second chair stand and timed up and down stairs tests were collected. KOOS data were dichotomised using established cut-off scores and logistic regression analyses were conducted for each subscale. RESULTS: Socio-demographic characteristics were similar to the Australian population. Normative reference data were generated for children (8-17 years) and adults (18-101 years). Female adults were up to twice as likely to report knee pain, symptoms and sport/recreation (Sport/Rec) limitations compared to males (P < .05). Older age, lower self-efficacy, greater BMI, varus lower limb alignment, lower knee flexion ROM and lower hip external rotation (ER) strength were independently associated with knee pain and disability among adults. CONCLUSIONS: Age- and gender-stratified reference data for the KOOS and KOOS-Child have been developed to guide interpretation of results in practice and research for individuals with knee disorders. Psychological and physical factors are linked with self-reported knee pain/disability among adults, and longitudinal studies to investigate causation are required.


Subject(s)
Arthralgia/etiology , Knee Injuries/complications , Osteoarthritis, Knee/complications , Self Report , Adolescent , Adult , Aged , Aged, 80 and over , Disability Evaluation , Disabled Persons , Female , Humans , Knee Injuries/physiopathology , Male , Middle Aged , Osteoarthritis, Knee/physiopathology , Patient Reported Outcome Measures , Prognosis , Quality of Life , Range of Motion, Articular/physiology , Reference Values , Young Adult
6.
Br J Cancer ; 110(6): 1606-13, 2014 Mar 18.
Article in English | MEDLINE | ID: mdl-24548858

ABSTRACT

BACKGROUND: RAD21 is a component of the cohesion complex and is integral to chromosome segregation and error-free DNA repair. RAD21 is functionally important in tumour progression but its role in colorectal carcinoma (CRC) is unclear. We therefore assessed its clinicopathological and prognostic significance in CRC, as well as its effect on chemosensitivity. METHODS: A retrospective observation study examined RAD21 expression in 652 CRCs using a tissue microarray approach. Correlation with clinicopathological factors including gender, tumour grade, mucinous subtype, TNM stage, disease-specific survival (DSS), BRAF and KRAS mutation status, tumour p53 immunostaining, tumour microsatellite instability and tumour CpG island methylator phenotype was performed. Colorectal cancer cell clones with stable RAD21 knockdown were generated and tested for cellular sensitivity to conventional chemotherapeutic drugs. RESULTS: RAD21 expression was significantly correlated with male gender (56.7% vs 43.3%, P=0.02), well-differentiated histology (14.4% vs 4.0%, P=0.0001), higher T-stage (36.1% vs 27.0%, P=0.01), presence of metastasis (18.8% vs 12.6%, P=0.03), and shorter DSS (hazard ratio (HR) 1.4, 95% CI 1.1 to 1.9, P=0.01) in both univariate and multivariate analysis. RAD21 expression was associated with shorter DSS in patients with KRAS mutant tumours (HR:2.6, 95% CI:1.4-4.3, P=0.001) and in patients receiving adjuvant chemoradiotherapy (HR:1.9, 95% CI:1.2-3.0, P=0.008). Colorectal cancer cells with RAD21 knockdown exhibited enhanced sensitivity to 5-fluorouracil, either alone or in combination with oxaliplatin. CONCLUSIONS: RAD21 expression in CRC is associated with aggressive disease especially in KRAS mutant tumours and resistance to chemoradiotherapy. RAD21 may be an important novel therapeutic target.


Subject(s)
Biomarkers, Tumor/biosynthesis , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , Mutation , Nuclear Proteins/biosynthesis , Phosphoproteins/biosynthesis , Proto-Oncogene Proteins/genetics , ras Proteins/genetics , Adult , Aged , Aged, 80 and over , Biomarkers, Tumor/genetics , Cell Cycle Proteins , Colorectal Neoplasms/pathology , DNA-Binding Proteins , Female , Humans , Male , Middle Aged , Neoplasm Staging , Nuclear Proteins/genetics , Phosphoproteins/genetics , Prognosis , Proto-Oncogene Proteins p21(ras) , Retrospective Studies , Sex Factors , Tissue Array Analysis
8.
Intern Med J ; 41(7): 566-70, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21762335

ABSTRACT

5-Fluorouracil (5-FU) is a commonly used anti-neoplastic agent. 5-FU has been not uncommonly associated with cardiotoxicity, although the many potentially causative mechanisms are yet to be established. Here, we present the case of a 61-year-old gemstone miner who developed symptomatic sinus bradycardia while receiving a continuous 5-FU infusion combined with radiotherapy for locally advanced rectal cancer. This dysrhythmia is an unusual type of 5-FU toxicity, our case being the second described. We review the actions of 5-FU and the various proposed mechanisms of its cardiotoxic effects.


Subject(s)
Antimetabolites, Antineoplastic/adverse effects , Bradycardia/chemically induced , Fluorouracil/adverse effects , Antimetabolites, Antineoplastic/therapeutic use , Arrhythmia, Sinus/chemically induced , Arrhythmia, Sinus/diagnosis , Arrhythmia, Sinus/physiopathology , Bradycardia/physiopathology , Fluorouracil/therapeutic use , Humans , Infusions, Intravenous , Male , Middle Aged , Rectal Neoplasms/complications , Rectal Neoplasms/drug therapy
9.
Br J Cancer ; 102(10): 1511-8, 2010 May 11.
Article in English | MEDLINE | ID: mdl-20461094

ABSTRACT

BACKGROUND: About 1-5% of cancer patients suffer from significant normal tissue reactions as a result of radiotherapy (RT). It is not possible at this time to predict how most patients' normal tissues will respond to RT. DNA repair dysfunction is implicated in sensitivity to RT particularly in genes that mediate the repair of DNA double-strand breaks (DSBs). Phosphorylation of histone H2AX (phosphorylated molecules are known as gammaH2AX) occurs rapidly in response to DNA DSBs, and, among its other roles, contributes to repair protein recruitment to these damaged sites. Mammalian cell lines have also been crucial in facilitating the successful cloning of many DNA DSB repair genes; yet, very few mutant cell lines exist for non-syndromic clinical radiosensitivity (RS). METHODS: Here, we survey DNA DSB induction and repair in whole cells from RS patients, as revealed by gammaH2AX foci assays, as potential predictive markers of clinical radiation response. RESULTS: With one exception, both DNA focus induction and repair in cell lines from RS patients were comparable with controls. Using gammaH2AX foci assays, we identified a RS cancer patient cell line with a novel ionising radiation-induced DNA DSB repair defect; these data were confirmed by an independent DNA DSB repair assay. CONCLUSION: gammaH2AX focus measurement has limited scope as a pre-RT predictive assay in lymphoblast cell lines from RT patients; however, the assay can successfully identify novel DNA DSB repair-defective patient cell lines, thus potentially facilitating the discovery of novel constitutional contributions to clinical RS.


Subject(s)
DNA Breaks, Double-Stranded/radiation effects , DNA/metabolism , Genetic Techniques , Histones/radiation effects , Neoplasms/genetics , Radiation Tolerance/genetics , Adult , Aged , Aged, 80 and over , Biomarkers, Tumor/genetics , Cell Line, Tumor , DNA Repair , Female , Fluorescent Antibody Technique , Histones/metabolism , Humans , Male , Middle Aged , Neoplasms/radiotherapy , Phenotype , Phosphorylation
10.
Australas Radiol ; 50(6): 607, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17107536
13.
Lancet ; 361(9360): 836-8, 2003 Mar 08.
Article in English | MEDLINE | ID: mdl-12642053

ABSTRACT

Despite advances in the molecular pathogenesis of glioblastoma multiforme, no reliable prognostic markers have been identified. We analysed telomerase activity and telomere lengths in glioblastoma multiformes from 77 patients. 19 patients (25%) had tumours with the alternative-lengthening-of-telomere (ALT) phenotype. Median survival for patients with this phenotype was 542 days (95% CI 114-970) compared with 247 days (224-270) for glioblastoma multiformes with normal telomeres (p=0.0003). Cox's regression analysis showed that this association is independent of age. In patients with non-ALT tumours, telomerase activity did not affect survival (median 287 [199-375] vs 236 [230-242] days, p=0.275). We conclude that ALT is a prognostic indicator for patients with glioblastoma multiforme.


Subject(s)
Astrocytoma/enzymology , Glioblastoma/enzymology , Telomerase/metabolism , Telomere/genetics , Adult , Astrocytoma/mortality , Astrocytoma/pathology , Glioblastoma/mortality , Glioblastoma/pathology , Humans , Middle Aged , Phenotype , Prognosis , Survival Analysis
14.
Radiat Res ; 156(6): 724-30, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11741496

ABSTRACT

We investigated a radiotherapy-induced flare and subsequent clearance of skin lesions of a patient with the rare, dominantly inherited genodermatosis, Darier's disease (DD). The DD gene, ATP2A2, was recently isolated and shown to be a cation pump responsible for regulating intracellular calcium homeostasis. A severe exacerbation of Darier's skin lesions developed within the radiation field when 40 Gy of palliative thoracic external-beam radiation therapy and concurrent chemotherapy (cisplatin and hydroxyurea) were delivered for non-small cell lung cancer. The DD lesions subsequently completely cleared from irradiated skin, as they did when a subsequent course of radiation alone was given for a loco-regional tumor recurrence. The two radiation therapy-treated areas of skin remained free from lesions of the skin disorder until the patient's death from progressive lung cancer 9 months later. The nucleotide sequence of the patient's ATP2A2 gene was determined by PCR-based cycle sequencing. We identified four nucleotide sequence variants in the ATP2A2 gene in this patient. Three were probable polymorphisms and the other appeared to be a novel disease-causing mutation (R751Q), situated in the transmembrane portion of the ATP2A2 protein. This finding confirmed the clinical diagnosis. Since epidermis turns over every 3-4 weeks, total and persistent clearance of the DD lesions by chemoradiotherapy suggests that this treatment induced sustained differentiation of the DD-affected skin by an unknown mechanism. Oncologists treating malignant disease in patients with DD should anticipate temporary deterioration in DD-involved irradiated skin. Radiation therapy has therapeutic potential in severe DD.


Subject(s)
Carcinoma, Non-Small-Cell Lung/radiotherapy , Darier Disease/etiology , Epidermis/radiation effects , Lung Neoplasms/radiotherapy , Mutation , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Base Sequence , Calcium-Transporting ATPases/genetics , Carcinoma, Non-Small-Cell Lung/drug therapy , Cell Differentiation/radiation effects , Cisplatin/administration & dosage , Combined Modality Therapy , DNA Primers , Darier Disease/genetics , Darier Disease/pathology , Epidermal Cells , Humans , Hydroxyurea/administration & dosage , Lung Neoplasms/drug therapy , Male , Middle Aged , Polymerase Chain Reaction , Radiotherapy/adverse effects , Sarcoplasmic Reticulum Calcium-Transporting ATPases
15.
Cardiovasc Drug Rev ; 19(3): 245-62, 2001.
Article in English | MEDLINE | ID: mdl-11607042

ABSTRACT

Somatic gene therapy of vascular diseases is a promising new field in modern medicine. Recent advancements in gene transfer technology have greatly evolved our understanding of the pathophysiologic role of candidate disease genes. With this knowledge, the expression of selective gene products provides the means to test the therapeutic use of gene therapy in a multitude of medical conditions. In addition, with the completion of genome sequencing programs, gene transfer can be used also to study the biologic function of novel genes in vivo. Novel genes are delivered to targeted tissue via several different vehicles. These vectors include adenoviruses, retroviruses, plasmids, plasmid/liposomes, and oligonucleotides. However, each one of these vectors has inherent limitations. Further investigations into developing delivery systems that not only allow for efficient, targeted gene transfer, but also are stable and nonimmunogenic, will optimize the clinical application of gene therapy in vascular diseases. This review further discusses the available mode of gene delivery and examines six major areas in vascular gene therapy, namely prevention of restenosis, thrombosis, hypertension, atherosclerosis, peripheral vascular disease in congestive heart failure, and ischemia. Although we highlight some of the recent advances in the use of gene therapy in treating vascular disease discovered primarily during the past two years, many excellent studies published during that period are not included in this review due to space limitations. The following is a selective review of practical uses of gene transfer therapy in vascular diseases. This review primarily covers work performed in the last 2 years. For earlier work, the reader may refer to several excellent review articles. For instance, Belalcazer et al. (6) reviewed general aspects of somatic gene therapy and the different vehicles used for the delivery of therapeutic genes. Gene therapy in restenosis and stimulation of angiogenesis in the cardiac muscle are discussed in reviews by several investigators (13,26,57,74,83). In another review, Meyerson et al. (43) discuss advances in gene therapy for vascular proliferative disorders and chronic peripheral and cardiac ischemia.


Subject(s)
Genetic Therapy , Vascular Diseases/therapy , Animals , Genetic Vectors , Humans
16.
Genomics ; 77(1-2): 5-7, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11543626

ABSTRACT

Cell cycle defects have been associated with the process of carcinogenesis in many studies. Here we report the cloning and analysis of the novel gene KIAA0008 (GenBank acc. no. D13633). Chromosomal localization experiments assigned the gene to chromosome 14q22-q23. The mRNA transcript was found to be cell cycle regulated, expressed at S-phase, and maintained at both G2-and M-phases. In situ hybridization showed expression in proliferating colon and breast (tumor) tissues. Structurally, KIAA0008 shares homology with the Drosophila melanogaster discs large-1 (dlg1) tumor suppressor gene and membrane-associated guanylate kinase protein family members. The potential involvement of KIAA0008 in cell proliferation is discussed, along with its sequence identity and tissue distribution.


Subject(s)
Cell Cycle/physiology , Genes, Tumor Suppressor/genetics , Proteins/genetics , Adaptor Proteins, Signal Transducing , Animals , Blotting, Northern , Breast Neoplasms/genetics , Chromosome Mapping , Chromosomes, Human, Pair 14/genetics , Colonic Neoplasms/genetics , Discs Large Homolog 1 Protein , Drosophila melanogaster/genetics , Female , Gene Expression Regulation , Gene Expression Regulation, Neoplastic , HeLa Cells , Humans , In Situ Hybridization , Male , Membrane Proteins , Neoplasm Proteins , RNA/genetics , RNA/metabolism , Tissue Distribution
17.
Australas Radiol ; 45(2): 200-4, 2001 May.
Article in English | MEDLINE | ID: mdl-11380364

ABSTRACT

The role of breast conservation therapy (limited surgery and irradiation of the breast with/without axilla) in the approximately 5% of breast cancer patients who harbour a germline mutation in BRCA1 or BRCA2, is a largely unexplored area and is seen by some as controversial. The relatively high cumulative risk of second primary cancers in such patients and concern about a possible decreased ability of mutation carriers to repair DNA damage caused by radiation has fuelled this controversy. Published studies of breast conservation therapy in carriers of a mutation in BRCA1 or BRCA2 are reviewed, with particular attention to their methodology. These studies have not demonstrated any increase in radiation sensitivity of normal tissues in mutation carriers, either in terms of increased early or late toxicity or tumourigenesis. Likewise, tumour sensitivity to radiotherapy, which might be expected based on the known functions of the BRCA1 and BRCA2 genes, has not been documented to date in mutation carriers. Further, methodologically rigorous studies of large numbers of breast cancer patients who carry a mutation in BRCA1 or BRCA2 are required to fully elucidate these issues.


Subject(s)
Breast Neoplasms/surgery , Genes, BRCA1/genetics , Genes, Tumor Suppressor/genetics , Germ-Line Mutation , Mastectomy, Segmental , BRCA2 Protein , Breast Neoplasms/genetics , Female , Humans , Neoplasm Proteins/genetics , Transcription Factors/genetics
18.
Curr Biol ; 10(22): 1463-6, 2000 Nov 16.
Article in English | MEDLINE | ID: mdl-11102811

ABSTRACT

'Cohesin' is a highly conserved multiprotein complex thought to be the primary effector of sister-chromatid cohesion in all eukaryotes. Cohesin complexes in budding yeast hold sister chromatids together from S phase until anaphase, but in metazoans, cohesin proteins dissociate from chromosomes and redistribute into the whole cell volume during prophase, well before sister chromatids separate (reviewed in [1,2]). Here we address this apparent anomaly by investigating the cell-cycle dynamics of DRAD21, the Drosophila orthologue of the Xenopus XRAD21 and Saccharomyces cerevisiae Scc1p/Mcd1p cohesins [3]. Analysis of DRAD21 in S2 Drosophila tissue culture cells and live embryos expressing a DRAD21-green fluorescent protein (GFP) fusion revealed the presence of four distinct subcellular pools of DRAD21: a cytoplasmic pool; a chromosome-associated pool which dissociates from chromatin as chromosomes condense in prophase; a short-lived centrosome-associated pool present during metaphase-anaphase; and a centromere-proximal pool which remains bound to condensed chromosomes, is found along the junction of sister chromatids between kinetochores, and persists until the metaphase-anaphase transition. We conclude that in Drosophila, and possibly all metazoans, a minor pool of cohesin remains bound to centromere-proximal chromatin after prophase and maintains sister-chromatid cohesion until the metaphase-anaphase transition.


Subject(s)
Cell Cycle Proteins , Centromere/metabolism , Drosophila Proteins , Nuclear Proteins/metabolism , Phosphoproteins/metabolism , Saccharomyces cerevisiae Proteins , Xenopus Proteins , Animals , Apoptosis Regulatory Proteins , Cell Cycle , Cell Line , Chromosomal Proteins, Non-Histone , Drosophila , Fungal Proteins , Mitosis/physiology , Recombinant Fusion Proteins/metabolism , Cohesins
19.
Gene ; 250(1-2): 77-84, 2000 May 30.
Article in English | MEDLINE | ID: mdl-10854781

ABSTRACT

Cohesin is an evolutionarily conserved multiprotein complex required to establish and maintain sister chromatid cohesion. Here, we report the cloning and initial characterization of the Drosophila homologue of the fission yeast rad21 cohesin subunit, called Drad21. The Drad21 coding region was localized to centromeric heterochromatin and encodes a 715 amino acid (aa) protein with 42% aa identity to vertebrate Rad21p-homologues, 25% with Scc1p/Mcd1p (S. cerevisiae) and 28% with Rad21p (S. pombe). Sequences with similarity to the sites of proteolytic cleavage identified in Scc1p/Mcd1p are not evident in DRAD21. Northern blot and mRNA in-situ studies show that Drad21 is developmentally regulated, with high levels of expression in early embryogenesis, in S-phase cells of proliferating imaginal tissues, and in the early endocycling cells of the embryonic gut.


Subject(s)
Cell Cycle Proteins/genetics , Drosophila Proteins , Drosophila/genetics , Insect Proteins/genetics , Nuclear Proteins/genetics , S Phase , Schizosaccharomyces pombe Proteins , Amino Acid Sequence , Animals , Base Sequence , Blotting, Northern , Chromosomal Proteins, Non-Histone , DNA/chemistry , DNA/genetics , DNA, Complementary/chemistry , DNA, Complementary/genetics , Drosophila/cytology , Drosophila/embryology , Embryo, Nonmammalian/metabolism , Embryonic Development , Exons , Female , Fungal Proteins , Gene Expression , Gene Expression Regulation, Developmental , Genes, Insect/genetics , In Situ Hybridization , Introns , Male , Molecular Sequence Data , Phosphoproteins/genetics , RNA/genetics , RNA/metabolism , Sequence Alignment , Sequence Analysis, DNA , Sequence Homology, Amino Acid , Tissue Distribution , Cohesins
20.
J Clin Endocrinol Metab ; 85(4): 1518-24, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10770191

ABSTRACT

Insulin-like growth factor-I (IGF-I) enhances insulin action in normal subjects and in patients with both type 1 and 2 diabetes; however, its administration is associated with significant side effects in a high percentage of patients. The coadministration of IGF binding protein-3 (IGFBP-3, the predominant IGF binding protein in serum) with IGF-I limits IGF-I inducible side effects, but it does not attenuate the ability of IGF-I to enhance protein synthesis and bone accretion; therefore, we determined whether IGF-I/IGFBP-3 would retain biological activity in type 1 DM and limit side effects associated with free IGF-I administration. Twelve patients received recombinant human IGF-I plus IGFBP-3 (2 mg/kg-day) by continuous sc infusion for 2 weeks. Each subject served as his own control; and, during a paired 2-week period, each received a placebo infusion. The order of the treatments was randomized. Subjects were placed on a constant caloric intake but were allowed to adjust insulin doses to maintain appropriate levels of glycemic control. Subjects measured blood glucose four times per day at home and kept a log of their insulin use. Frequent sampling for glucose, insulin, and GH was conducted during four inpatient study periods, one at the beginning and one at the end of each 2-week study interval. During IGF-I/IGFBP-3, insulin doses were reduced by 49%, and mean serum glucose was reduced by 23%. Free insulin levels obtained during frequent sampling in hospital fell 47% on IGF-I/IGFBP-3, compared with control, but showed no change with placebo. Concomitant glucose measurements did not differ in the two treatment groups. There was no change in body weight. Fructosamine levels decreased by 12%, but this was not significant (P < 0.1). Fasting triglyceride was unchanged, but cholesterol declined from 170 +/- 24 to 149 +/- 31 mg/dL (P < 0.05). IGFBP-2 (an IGF-I-dependent responsive variable) rose from 141 +/- 56 to 251 +/- 98 ng/mL (P < 0.01) on IGF-I/IGFBP-3. To analyze the mechanism by which IGF-I/IGFBP-3 might reduce insulin requirements, the change in serum GH was quantified. Mean GH levels were reduced by 72%, from 2.48 to 0.55 ng/mL (P < 0.001). An equal number (40%) of drug- and placebo-treated subjects had minor hypoglycemic episodes at home that required adjustment of insulin doses. No episode was classified as severe. In contrast to previous studies with free IGF-I, there were no cases of edema, headache, jaw pain, retinal edema, or Bell's palsy. No subject withdrew because of drug complications. These findings indicate that IGF-I/IGFBP-3 is biologically active on carbohydrate metabolism, as measured by a decrease in insulin requirements in patients with type 1 diabetes. Further studies will be required to determine the long-term safety and efficacy of this combination in patients with insulin resistance and diabetes.


Subject(s)
Diabetes Mellitus, Type 1/drug therapy , Insulin-Like Growth Factor Binding Protein 3/administration & dosage , Insulin-Like Growth Factor I/administration & dosage , Insulin/administration & dosage , Adult , Blood Glucose/metabolism , Cross-Over Studies , Diabetes Mellitus, Type 1/blood , Double-Blind Method , Human Growth Hormone/metabolism , Humans , Insulin/therapeutic use , Insulin-Like Growth Factor Binding Protein 3/adverse effects , Insulin-Like Growth Factor Binding Protein 3/therapeutic use , Insulin-Like Growth Factor I/adverse effects , Insulin-Like Growth Factor I/therapeutic use , Placebos
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