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2.
Diabetes Res Clin Pract ; 98(3): 414-21, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23116534

ABSTRACT

UNLABELLED: Pregnancy in women with type 1 diabetes mellitus (T1DM) is generally associated with increased insulin requirements. AIMS: To determine the frequency and significance of declining insulin requirements in late gestation in women with T1DM. METHODS: We conducted a retrospective review of 54 women seen at our institution from 2006 to 2010 with a diagnosis of T1DM pre-pregnancy and presentation for antenatal care prior to 28 weeks. Information was collected regarding patient demographics, insulin dose and pregnancy outcome. A 15% difference in weight-adjusted basal insulin from 30 weeks gestation to delivery was considered significant. RESULTS: Five women (9.3%) had a fall of 15% or more and 23 (42.5%) had a rise of 15% or more rise in insulin requirements. There were fewer neonatal intensive care admissions but more infants with an APGAR <8 at 5 min in women with a fall in insulin requirements. These differences were not evident when the data were re-analysed by quartiles of change. CONCLUSIONS: In most women with T1DM, insulin requirements show little change from 30 weeks gestation until delivery. Almost 10% of women had a significant fall in insulin requirements which did not correlate with adverse neonatal outcome. These results require validation in a larger, prospective trial.


Subject(s)
Diabetes Mellitus, Type 1/drug therapy , Hypoglycemic Agents/administration & dosage , Insulin/administration & dosage , Pregnancy in Diabetics/drug therapy , Adult , Cohort Studies , Diabetes Mellitus, Type 1/blood , Dose-Response Relationship, Drug , Drug Monitoring , Drug Resistance , Electronic Health Records , Female , Humans , Hypoglycemic Agents/therapeutic use , Insulin/therapeutic use , Outpatient Clinics, Hospital , Pregnancy , Pregnancy Outcome , Pregnancy Trimester, Third , Pregnancy in Diabetics/blood , Prenatal Care , Queensland , Retrospective Studies , Telemedicine
3.
Obstet Med ; 4(1): 30-4, 2011 Mar.
Article in English | MEDLINE | ID: mdl-27579094

ABSTRACT

Gastroparesis is a syndrome characterized by delayed gastric emptying in the absence of mechanical obstruction. The most common underlying aetiology is diabetes mellitus; however, many cases are idiopathic. Pregnancy per se is associated with gastrointestinal neuromuscular dysfunction; however, reports of gastroparesis arising during pregnancy are rare. We report a case of severe gastroparesis and proximal small bowel paresis presenting during pregnancy.

4.
Lancet ; 370(9600): 1687-97, 2007 Nov 17.
Article in English | MEDLINE | ID: mdl-17988728

ABSTRACT

BACKGROUND: Laser treatment for diabetic retinopathy is often associated with visual field reduction and other ocular side-effects. Our aim was to assess whether long-term lipid-lowering therapy with fenofibrate could reduce the progression of retinopathy and the need for laser treatment in patients with type 2 diabetes mellitus. METHODS: The Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study was a multinational randomised trial of 9795 patients aged 50-75 years with type 2 diabetes mellitus. Eligible patients were randomly assigned to receive fenofibrate 200 mg/day (n=4895) or matching placebo (n=4900). At each clinic visit, information concerning laser treatment for diabetic retinopathy-a prespecified tertiary endpoint of the main study-was gathered. Adjudication by ophthalmologists masked to treatment allocation defined instances of laser treatment for macular oedema, proliferative retinopathy, or other eye conditions. In a substudy of 1012 patients, standardised retinal photography was done and photographs graded with Early Treatment Diabetic Retinopathy Study (ETDRS) criteria to determine the cumulative incidence of diabetic retinopathy and its component lesions. Analyses were by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN64783481. FINDINGS: Laser treatment was needed more frequently in participants with poorer glycaemic or blood pressure control than in those with good control of these factors, and in those with a greater burden of clinical microvascular disease, but the need for such treatment was not affected by plasma lipid concentrations. The requirement for first laser treatment for all retinopathy was significantly lower in the fenofibrate group than in the placebo group (164 [3.4%] patients on fenofibrate vs 238 [4.9%] on placebo; hazard ratio [HR] 0.69, 95% CI 0.56-0.84; p=0.0002; absolute risk reduction 1.5% [0.7-2.3]). In the ophthalmology substudy, the primary endpoint of 2-step progression of retinopathy grade did not differ significantly between the two groups overall (46 [9.6%] patients on fenofibrate vs 57 [12.3%] on placebo; p=0.19) or in the subset of patients without pre-existing retinopathy (43 [11.4%] vs 43 [11.7%]; p=0.87). By contrast, in patients with pre-existing retinopathy, significantly fewer patients on fenofibrate had a 2-step progression than did those on placebo (three [3.1%] patients vs 14 [14.6%]; p=0.004). An exploratory composite endpoint of 2-step progression of retinopathy grade, macular oedema, or laser treatments was significantly lower in the fenofibrate group than in the placebo group (HR 0.66, 95% CI 0.47-0.94; p=0.022). INTERPRETATION: Treatment with fenofibrate in individuals with type 2 diabetes mellitus reduces the need for laser treatment for diabetic retinopathy, although the mechanism of this effect does not seem to be related to plasma concentrations of lipids.


Subject(s)
Diabetic Retinopathy/drug therapy , Fenofibrate/therapeutic use , Hypolipidemic Agents/therapeutic use , Laser Therapy , Macular Edema/surgery , Aged , Diabetes Mellitus, Type 2/complications , Diabetic Retinopathy/etiology , Diabetic Retinopathy/surgery , Female , Humans , Lipids/blood , Macular Edema/complications , Male , Middle Aged , Treatment Outcome
5.
Lancet ; 366(9500): 1849-61, 2005 Nov 26.
Article in English | MEDLINE | ID: mdl-16310551

ABSTRACT

BACKGROUND: Patients with type 2 diabetes mellitus are at increased risk of cardiovascular disease, partly owing to dyslipidaemia, which can be amenable to fibrate therapy. We designed the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study to assess the effect of fenofibrate on cardiovascular disease events in these patients. METHODS: We did a multinational, randomised controlled trial with 9795 participants aged 50-75 years, with type 2 diabetes mellitus, and not taking statin therapy at study entry. After a placebo and a fenofibrate run-in phase, we randomly assigned patients (2131 with previous cardiovascular disease and 7664 without) with a total-cholesterol concentration of 3.0-6.5 mmol/L and a total-cholesterol/HDL-cholesterol ratio of 4.0 or more or plasma triglyceride of 1.0-5.0 mmol/L to micronised fenofibrate 200 mg daily (n=4895) or matching placebo (n=4900). Our primary outcome was coronary events (coronary heart disease death or non-fatal myocardial infarction); the outcome for prespecified subgroup analyses was total cardiovascular events (the composite of cardiovascular death, myocardial infarction, stroke, and coronary and carotid revascularisation). Analysis was by intention to treat. The study was prospectively registered (number ISRCTN 64783481). FINDINGS: Vital status was confirmed on all but 22 patients. Averaged over the 5 years' study duration, similar proportions in each group discontinued study medication (10% placebo vs 11% fenofibrate) and more patients allocated placebo (17%) than fenofibrate (8%; p<0.0001) commenced other lipid treatments, predominantly statins. 5.9% (n=288) of patients on placebo and 5.2% (n=256) of those on fenofibrate had a coronary event (relative reduction of 11%; hazard ratio [HR] 0.89, 95% CI 0.75-1.05; p=0.16). This finding corresponds to a significant 24% reduction in non-fatal myocardial infarction (0.76, 0.62-0.94; p=0.010) and a non-significant increase in coronary heart disease mortality (1.19, 0.90-1.57; p=0.22). Total cardiovascular disease events were significantly reduced from 13.9% to 12.5% (0.89, 0.80-0.99; p=0.035). This finding included a 21% reduction in coronary revascularisation (0.79, 0.68-0.93; p=0.003). Total mortality was 6.6% in the placebo group and 7.3% in the fenofibrate group (p=0.18). Fenofibrate was associated with less albuminuria progression (p=0.002), and less retinopathy needing laser treatment (5.2%vs 3.6%, p=0.0003). There was a slight increase in pancreatitis (0.5%vs 0.8%, p=0.031) and pulmonary embolism (0.7%vs 1.1%, p=0.022), but no other significant adverse effects. INTERPRETATION: Fenofibrate did not significantly reduce the risk of the primary outcome of coronary events. It did reduce total cardiovascular events, mainly due to fewer non-fatal myocardial infarctions and revascularisations. The higher rate of starting statin therapy in patients allocated placebo might have masked a moderately larger treatment benefit.


Subject(s)
Cardiovascular Diseases/prevention & control , Cholesterol/blood , Diabetes Mellitus, Type 2/complications , Dyslipidemias/drug therapy , Fenofibrate/therapeutic use , Hypolipidemic Agents/therapeutic use , Triglycerides/blood , Aged , Cardiovascular Diseases/etiology , Coronary Disease/mortality , Coronary Disease/prevention & control , Diabetes Mellitus, Type 2/blood , Double-Blind Method , Dyslipidemias/complications , Female , Fenofibrate/adverse effects , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Hypolipidemic Agents/adverse effects , Male , Middle Aged
6.
Climacteric ; 8(3): 251-62, 2005 Sep.
Article in English | MEDLINE | ID: mdl-16390757

ABSTRACT

OBJECTIVES: To assess the efficacy and tolerability of risedronate, a pyridinyl bisphosphonate, in preventing loss of bone mineral density (BMD) of the lumbar spine and proximal femur in early postmenopausal women. METHODS: A total of 383 patients were randomly assigned to receive risedronate 2.5 or 5 mg or placebo once daily for 24 months. All patients received 1 g elemental calcium daily. BMD was measured by dual X-ray absorptiometry at baseline and at 3, 6, 12, 18, and 24 months. RESULTS: Risedronate 5 mg significantly increased BMD at the lumbar spine and femoral neck and trochanter in early postmenopausal women. Significant results were observed as early as 3 months. In the control calcium-supplemented group, BMD decreased steadily at each site throughout the study. The mean percentage change from baseline in BMD in the risedronate 5 mg group was significantly different from that in the control group at each determination at each site. At 24 months, the differences were 4.5 +/- 0.45% at the lumbar spine, 3.3 +/- 0.49% at the femoral neck, and 4.3 +/- 0.67% at the femoral trochanter. Risedronate 2.5 mg maintained BMD at each site, although the effect was less pronounced than that of risedronate 5 mg. Risedronate was well tolerated and was not associated with an increased incidence of overall or upper gastrointestinal adverse events. CONCLUSIONS: Risedronate 5 mg prevents bone loss in early postmenopausal women, is well tolerated, and represents an effective choice to maintain bone mass and prevent osteoporosis.


Subject(s)
Bone Density Conservation Agents/therapeutic use , Etidronic Acid/analogs & derivatives , Osteoporosis, Postmenopausal/prevention & control , Absorptiometry, Photon , Adult , Amino Acids/blood , Biomarkers/blood , Creatinine/blood , Dose-Response Relationship, Drug , Double-Blind Method , Etidronic Acid/therapeutic use , Female , Femur , Humans , Lumbar Vertebrae , Middle Aged , Prospective Studies , Risedronic Acid , Treatment Outcome
7.
J Clin Pharm Ther ; 27(5): 371-6, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12383139

ABSTRACT

OBJECTIVES: To compare variability of blood glucose concentration in patients with type II diabetes with (cases) and without (controls) myocardial infarction. A secondary objective was identification of predictive factors for higher blood glucose on discharge from hospital. DESIGN: A retrospective matched case-control study. PARTICIPANTS: Medical notes of 101 type II diabetic patients admitted with a myocardial infarction (MI) and 101 type II diabetic patients (controls) matched on gender and age with no MI were reviewed. Blood glucose concentrations over two consecutive 48-h periods were collected. Demographic data and therapy on admission/discharge were also collected. RESULTS: Patient characteristics were comparable on recruitment excluding family history of cardiovascular disease (P=0.003), dyslipidaemia (P=0.004) and previous history of MI (P=0.007). Variability of blood glucose in cases was greater over the first 48 h compared with the second 48 h (P=0.03), and greater when compared with controls over the first 48 h (P=0.01). Cases with blood glucose on discharge >8.2 mmol / L (n=45) were less likely to have a history of previous MI (P=0.04), ischaemic heart disease (P=0.03) or hypertension (P=0.02). CONCLUSIONS: Type II diabetics with an MI have higher and more variable blood glucose concentrations during the first 48 h of admission. Only cardiovascular 'high risk' patients had target blood glucose set on discharge. The desirability of all MI patients with diabetes, having standardized-glucose infusions to reduce variability of blood glucose, should be evaluated in a randomized controlled trial.


Subject(s)
Blood Glucose/analysis , Diabetes Mellitus, Type 2/complications , Myocardial Infarction/complications , Aged , Case-Control Studies , Diabetes Mellitus, Type 2/blood , Female , Humans , Male , Myocardial Infarction/blood , Retrospective Studies , Risk Factors , Time Factors
8.
JOP ; 1(4): 208-10, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11856863

ABSTRACT

CONTEXT, The prevalence of cystic fibrosis-related diabetes mellitus is increasing and is associated with increased survival from cystic fibrosis. CASE REPORT, This study describes a case of the premature onset of disabling and widespread microvascular complications resulting from cystic fibrosis-related diabetes mellitus. Previously asymptomatic retinopathy was diagnosed on recognition of diabetic nephropathy. CONCLUSIONS, The treatment of pulmonary exacerbations has become more complex due to the nephrotoxic potential of intravenous aminoglycoside drugs which are frequently used to control chronic Pseudomonas infection in cystic fibrosis.


Subject(s)
Cystic Fibrosis/physiopathology , Diabetes Mellitus/physiopathology , Microcirculation/physiopathology , Adult , Aminoglycosides , Anti-Bacterial Agents/adverse effects , Anti-Bacterial Agents/therapeutic use , Diabetic Nephropathies/diagnosis , Female , Humans , Lactams , Pneumonia, Bacterial/blood , Pneumonia, Bacterial/diagnosis , Pneumonia, Bacterial/drug therapy , Pseudomonas Infections/diagnosis , Pseudomonas Infections/drug therapy , Renal Insufficiency/blood , Renal Insufficiency/diagnosis
9.
Am J Cardiol ; 80(1): 39-44, 1997 Jul 01.
Article in English | MEDLINE | ID: mdl-9205017

ABSTRACT

We directly compared the safety and efficacy of atorvastatin and simvastatin in hypercholesterolemic patients. This 1-year, randomized, double-blind study was performed at 9 community- and university-based research hospitals in Australia. One-hundred seventy-seven patients between the ages of 18 and 80 years with baseline low-density-lipoprotein (LDL) cholesterol > or = 4.14 and < or = 7.76 mmol/L (160 and 300 mg/dl, respectively) and triglycerides < or = 4.52 mmol/L (400 mg/dl) received once-daily dosing with atorvastatin (Lipitor) 10 mg or simvastatin (Zocor) 10 mg. At week 16, the dose of medication was titrated to atorvastatin 20 mg or simvastatin 20 mg if patients did not meet LDL cholesterol target of < or = 3.36 mmol/L (130 mg/dl). Efficacy was reported as percent change from baseline in LDL cholesterol, total cholesterol, very low density lipoprotein cholesterol, total triglycerides, high-density lipoprotein cholesterol, apolipoproteins AI and B, and lipoprotein(a). Atorvastatin caused significantly greater reductions from baseline than did simvastatin for LDL cholesterol, total cholesterol, very low density lipoprotein cholesterol, triglycerides, and apolipoprotein B (p <0.05). No patient in either treatment group had clinically important elevations in creatine phosphokinase, alanine aminotransaminase, or aspartate aminotransaminase. No serious adverse events were considered associated with treatment. With atorvastatin 10 mg, 46% of the patients achieved LDL cholesterol target goal by week 16, whereas only 27% of the simvastatin patients achieved the target goal at the 10-mg dose. This cholesterol-lowering profile affords utility in many patient types.


Subject(s)
Anticholesteremic Agents/therapeutic use , Heptanoic Acids/therapeutic use , Hypercholesterolemia/drug therapy , Hyperlipidemias/drug therapy , Lovastatin/analogs & derivatives , Pyrroles/therapeutic use , Adult , Aged , Aged, 80 and over , Apolipoproteins B/blood , Apolipoproteins B/drug effects , Arthralgia/chemically induced , Atorvastatin , Cholesterol/blood , Cholesterol, Dietary/administration & dosage , Cholesterol, LDL/blood , Cholesterol, LDL/drug effects , Double-Blind Method , Female , Heptanoic Acids/pharmacology , Humans , Hypercholesterolemia/blood , Hypercholesterolemia/complications , Hyperhidrosis/chemically induced , Hyperlipidemias/complications , Lovastatin/pharmacology , Lovastatin/therapeutic use , Male , Middle Aged , Patient Education as Topic , Pyrroles/pharmacology , Simvastatin , Triglycerides/blood
11.
Mol Endocrinol ; 6(4): 581-8, 1992 Apr.
Article in English | MEDLINE | ID: mdl-1584222

ABSTRACT

The proximal region of the rat PRL gene contains at least five transcription-stimulating elements that are located within a 170-basepair region up-stream of the TATA box. These cis-acting elements include four binding sites for the pituitary-specific transcription factor Pit-1 as well as another site for an unidentified factor. In this study interactions between different DNA elements have been examined through the construction of PRL-luciferase fusion genes containing mutations that disrupt various combinations of the individual DNA elements. In general, the disruption of multiple factor-binding sites had a much more than additive effect on expression of the luciferase constructs. Interestingly, comparison of the effects of disrupting pairs of binding sites demonstrated substantial differences in the effects of different combinations of mutations, suggesting that cooperative interactions may reflect specific interactions. Mutations that disrupted all five cis-elements of the PRL proximal region essentially abolished transcription from the proximal promoter. This finding suggests that there are no other DNA elements within the proximal 200 basepairs of the PRL gene that can independently stimulate transcription. Although there is strong functional cooperativity between different cis-elements in the PRL gene, DNase footprint studies failed to detect cooperative binding between different Pit-1 elements. Overall, the findings demonstrate that the normal transcription of the PRL gene involves strong cooperative interactions between individual DNA elements in the proximal region.


Subject(s)
Gene Expression Regulation , Genes, Regulator , Prolactin/genetics , Transcription, Genetic , Animals , Binding Sites , Cell Line , DNA-Binding Proteins/metabolism , Luciferases/genetics , Luciferases/metabolism , Molecular Sequence Data , Mutagenesis, Site-Directed , Pituitary Neoplasms , Rats , TATA Box , Transcription Factor Pit-1 , Transcription Factors/metabolism , Transfection
13.
In Vitro Cell Dev Biol ; 27A(3 Pt 1): 197-204, 1991 Mar.
Article in English | MEDLINE | ID: mdl-1903381

ABSTRACT

An effect of the hormone, 1 alpha,25-dihydroxyvitamin D3 [1,25(OH)2D3] on hormone secretion by normal rat pituitary cells was investigated in vitro. Based on previous findings using GH4C1 cells, dispersed anterior pituitary cell cultures were prepared and maintained in serum-free conditions for up to 6 d. Under these circumstances, there was no effect of 1,25(OH)2D3 to alter medium or cell-associated levels of thyrotropin (TSH), prolactin (PRL), or growth hormone (GH). Cultures maintained under these conditions had lower medium and cell-associated hormone levels and lesser responses to agonists than cultures maintained in serum-supplemented medium. In the presence of 10% charcoal-treated fetal bovine serum, treatment with 10(-8) M 1,25(OH)2D3 for 24 h selectively increased TRH (10(-10) to 10(-7) M)-induced TSH secretion (P less than 0.001), with maximal enhancement observed at 10(-9) M TSH-releasing hormone (TRH). Enhancement of TSH secretion by 1,25(OH)2D3 was detected after 15 min exposure to TRH. There was no effect on agonist-induced PRL or GH secretion or on cell-associated hormone levels. The effect was evident after 24 h treatment with 1,25(OH)2D3, and decreased thereafter. Several other steroid hormones had no effect on 10(-9) M TRH-induced TSH secretion. These data contrast with the effect of 1,25(OH)2D3 in GH cells. They suggest that 1,25(OH)2D3 may act selectively in the normal pituitary to modulate TSH secretion.


Subject(s)
Calcitriol/pharmacology , Pituitary Gland, Anterior/metabolism , Thyrotropin/metabolism , Animals , Culture Media , Dopamine Antagonists , Estradiol/pharmacology , Female , Growth Hormone/metabolism , In Vitro Techniques , Prolactin/metabolism , Rats , Secretory Rate/drug effects , Tetrahydronaphthalenes/pharmacology , Thyrotropin-Releasing Hormone/pharmacology
14.
Mol Endocrinol ; 4(10): 1564-71, 1990 Oct.
Article in English | MEDLINE | ID: mdl-2178221

ABSTRACT

To identify DNA regions important for basal and hormone-stimulated transcription of the rat PRL gene, a series of clustered point mutations were prepared within the immediate 5' flanking region. DNA fragments representing the wild-type and 19 different linker-scanner mutations of the PRL gene were each linked to a luciferase marker gene, and the DNA constructs were transferred into GH3 pituitary tumor cells by electroporation. Luciferase activity was determined 24 h after transfection in extracts from control cells or cells treated with 0.5 mM chlorophenylthio-cAMP, 100 nM TRH, or 100 nM phorbol myristate acetate. The individual clustered point mutations covered a region from just up-stream of the TATA box (position -30) to a position 193 basepairs up-stream from the start of transcription. Five regions in which mutations produced substantial decreases in both basal and cAMP-, TRH-, or phorbol ester-stimulated expression of the marker gene were detected. Three of these regions (positions -41 to -58, -113 to -124, and -149 to -156) correspond to previously identified binding sites for the pituitary-specific, homeobox protein, Pit-1/GHF-1. The fourth and fifth regions do not correspond to Pit-1/GHF-1-binding sites and presumably represent sites for an unidentified factor. Within these regions, sequences with some similarity to a consensus cAMP response element and an AP-2-binding site have been detected. These data confirm the importance of Pit-1/GHF-1 as a key factor in PRL gene transcription. In addition, the results suggest that additional transcription factors are probably required for efficient expression of the PRL gene.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Mutagenesis , Prolactin/genetics , Promoter Regions, Genetic/genetics , Animals , Base Sequence , Binding Sites , Cyclic AMP/pharmacology , DNA/genetics , DNA-Binding Proteins/metabolism , Genetic Markers , Luciferases/genetics , Molecular Sequence Data , Pituitary Neoplasms , Rats , Repetitive Sequences, Nucleic Acid , Tetradecanoylphorbol Acetate/pharmacology , Thyrotropin-Releasing Hormone/pharmacology , Transcription Factor Pit-1 , Transcription Factors/metabolism , Transcription, Genetic , Transfection , Tumor Cells, Cultured
15.
Biochem Biophys Res Commun ; 164(1): 413-8, 1989 Oct 16.
Article in English | MEDLINE | ID: mdl-2679556

ABSTRACT

The in vitro effect of 1 alpha,25-dihydroxyvitamin D3 on the function of beta cells of the endocrine pancreas was investigated. Neonatal islets maintained in serum-free medium, or medium supplemented with 0.5% fetal bovine serum achieved a 2.5-fold increase in medium insulin levels in response to 10(8) M 1 alpha,25-dihydroxyvitamin D3 (P less than 0.001). The effect of 1,25-dihydroxyvitamin D3 required at least 96 h treatment to become evident and was similar at medium glucose concentrations of 10 and 20 mM. Cell-associated insulin was increased in 1 alpha,25-dihydroxyvitamin D3-treated cultures maintained in 0.5% serum. These data suggest that 1 alpha,25-dihydroxyvitamin D3 may have a direct effect in the beta cell.


Subject(s)
Calcitriol/pharmacology , Insulin/biosynthesis , Islets of Langerhans/drug effects , Animals , Animals, Newborn , In Vitro Techniques , Islets of Langerhans/metabolism , Rats , Rats, Inbred Strains
16.
J Endocrinol ; 121(3): 451-8, 1989 Jun.
Article in English | MEDLINE | ID: mdl-2502597

ABSTRACT

The hormone 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) has been shown to selectively enhance agonist-induced TSH release in the rat thyrotroph in vitro. The interaction of 1,25-(OH)2D3 with tri-iodo-thyronine (T3) and cortisol was studied in primary cultures of dispersed anterior pituitary cells. TRH (1 nmol/l)-induced TSH release over 1 h was enhanced by 70% (P less than 0.01) following exposure to 10 nmol 1,25-(OH)2D3/l for 24 h. Pretreatment with T3 (1 pmol/l-1 mumol/l) for 24 h caused a dose-dependent inhibition of TRH-induced TSH release. Net TRH-induced TSH release was inhibited by 85% at T3 concentrations of 3 nmol/l or greater. Co-incubation with 1,25-(OH)2D3 resulted in enhanced TRH-induced TSH release at all T3 concentrations tested (P less than 0.001). The increment of TRH-induced TSH release resulting from 1,25-(OH)2D3 pretreatment was equivalent in the presence or absence of maximal inhibitory T3 concentrations. At 1 nmol T3/l, there was a two- to threefold relative increase in 1,25-(OH)2D3-enhanced TRH-induced TSH release. Incubation with cortisol (100 pmol/l-100 nmol/l) had no effect on basal or TRH-induced TSH release, nor did it alter 1,25-(OH)2D3-enhanced TRH-induced TSH release when added 24 h before, or at the time of addition of 1,25-(OH)2D3. Actinomycin D and alpha-amanitin abolished 1,25-(OH)2D3-enhanced TSH secretion. These data demonstrate that the action of 1,25-(OH)2D3 in the thyrotroph required new RNA transcription, and was not affected by cortisol. In the presence of T3, the response of the thyrotroph to TRH induced by 1,25-(OH)2D3 was increased. We have shown that 1,25-(OH)2D3 has significant effects on the action of TRH and T3 in vitro. These findings support the proposal that 1,25-(OH)2D3 may modulate TSH secretion in vivo.


Subject(s)
Calcitriol/pharmacology , Pituitary Gland, Anterior/drug effects , Thyrotropin/metabolism , Amanitins/pharmacology , Animals , Cells, Cultured , Dactinomycin/pharmacology , Female , Hydrocortisone/pharmacology , Pituitary Gland, Anterior/cytology , Pituitary Gland, Anterior/metabolism , Rats , Rats, Inbred Strains , Thyrotropin-Releasing Hormone/pharmacology , Triiodothyronine/pharmacology
17.
J Endocrinol ; 121(3): 441-50, 1989 Jun.
Article in English | MEDLINE | ID: mdl-2474048

ABSTRACT

Vitamin D may regulate pituitary function, as there are selective effects of 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) on gene expression in clonal pituitary tumour cells, and on TRH-induced TSH release in normal rat pituitary cells in vitro. The role of Ca2+ in 1,25-(OH)2D3-enhanced TSH release from primary rat pituitary cell cultures was investigated. Pretreatment with 10 nmol 1,25-(OH)2D3/l for 24 h augmented KCl (3-60 mmol/l)-induced TSH release over 1 h at all KCl concentrations greater than 7.5 mmol/l (P less than 0.001), with a 76% enhancement of TSH release induced by 30 mmol KCl/l (P less than 0.001). The Ca2+ channel antagonist nifedipine (10 nmol/l-10 mumol/l) caused a concentration-dependent inhibition of KCl (60 mmol/l)-induced TSH secretion. Pretreatment with 1,25-(OH)2D3 enhanced KCl-induced release at all concentrations of nifedipine (P less than 0.001). The Ca2+ selective divalent cation ionophore ionomycin (1 nmol/l-1 mumol/l), and the Ca2+ channel agonist BAY K 8644 (10 nmol/l-1 mumol/l) increased prolactin secretion but did not increase TSH release, and 1,25-(OH)2D3 had no effect. At an extracellular Ca2+ concentration of less than 500 nmol/l, TRH-induced TSH release was observed only after treatment with 1,25-(OH)2D3 (P less than 0.01). As the extracellular Ca2+ concentration was increased, greater increments of TRH-induced TSH release were observed following pretreatment with 1,25-(OH)2D3 (P less than 0.01). However, the effect of 1,25-(OH)2D3 in the thyrotroph was independent of the pretreatment extracellular Ca2+ concentration. We have shown that 1,25-(OH)2D3 acts selectively on the thyrotroph to enhance in-vitro responsiveness to TRH and KCl. These data suggest that the action of 1,25-(OH)2D3 in the thyrotroph is to enhance intracellular signal transduction. They further support a permissive or regulatory role of vitamin D in the normal pituitary gland.


Subject(s)
Calcitriol/pharmacology , Calcium/pharmacology , Pituitary Gland, Anterior/drug effects , Thyrotropin/metabolism , 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology , Animals , Anti-Bacterial Agents/pharmacology , Cells, Cultured , Ethers/pharmacology , Female , Ionomycin , Nifedipine/pharmacology , Pituitary Gland, Anterior/cytology , Prolactin/metabolism , Rats , Rats, Inbred Strains
18.
Am J Med ; 84(1): 19-22, 1988 Jan.
Article in English | MEDLINE | ID: mdl-3337130

ABSTRACT

Fourteen patients with large non-toxic multinodular goiters were treated with 20 to 100 mCi (740 to 3,700 MBq) of radioactive iodine (iodine-131). In seven, the goiter had recurred after a partial thyroidectomy and four of these had had two operations. Eight had symptoms of respiratory obstruction, two had dysphagia, and the others sought treatment for cosmetic reasons. After administration of iodine-131, there was a significant decrease in goiter size in 11 of the 14 patients, and all those with obstructive symptoms showed improvement. No significant local side effects occurred, but hypothyroidism and Graves' disease each occurred once during follow-up from one to 13 years. Radioactive iodine in doses of 20 to 100 mCi is an effective, safe therapeutic alternative in patients with large non-toxic multinodular goiter, particularly when there is recurrence following surgery or when there are contraindications to surgery.


Subject(s)
Goiter, Nodular/radiotherapy , Iodine Radioisotopes/therapeutic use , Adult , Aged , Female , Follow-Up Studies , Goiter, Nodular/surgery , Humans , Male , Middle Aged , Recurrence , Thyroidectomy , Time Factors
19.
Endocrinology ; 121(3): 1192-4, 1987 Sep.
Article in English | MEDLINE | ID: mdl-3113918

ABSTRACT

The findings of specific binding of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] in normal rat pituitary tissue and selective effects of 1,25-(OH)2D3 on gene expression in clonal pituitary tumour cells have suggested that vitamin D may regulate pituitary function. Therefore, the in vitro effect of 1,25-(OH)2D3 on normal pituitary cells was investigated. Primary anterior pituitary cell cultures prepared from female rats were maintained in experimental medium +/- 10(-8) M 1,25-(OH)2D3 for up to 24 h and then incubated with fresh experimental medium containing TRH (10(-10)-10(-8) M) or vehicle for 1 h. Pretreatment with 1,25-(OH)2D3 for 24 h led to increased TSH release at all TRH concentrations tested (P less than 0.0001), a decrease in the half-maximal stimulatory dose of TRH for TSH release from 2 X 10(-9) M to 0.4 X 10(-9) M, a 22% increase in maximal TSH release (P less than 0.01), and an 81% increase in TSH release at 10(-9) M TRH (P less than 0.001). 1 X 10(-9) M 1,25-(OH)2D3 increased TRH (10(-9) M)-induced TSH release by 20% (P less than 0.05) but 10(-7) M and 10(-6) M 25-hydroxyvitamin D3 (25-OH D3) had no effect. The effect of 1,25-(OH)2D3 on TRH (10(-9) M)-induced TSH release was evident within 8 h and was maximal by 16 h. There was no effect on basal TSH release, TSH accumulation in the medium in the preceding 24 h nor on cell-associated TSH. 1,25-(OH)2D3 pretreatment had no effect on TRH-induced PRL secretion, PRL accumulation in the medium nor on cell-associated PRL. We have shown that 1,25-(OH)2D3 acts selectively on the thyrotroph to enhance in vitro responsiveness to physiologically relevant concentrations of TRH. These findings are consistent with the reported autoradiographic localization of [3H]-1,25-(OH)2D3 in the thyrotroph and support a permissive or regulatory role of vitamin D in the normal pituitary gland.


Subject(s)
Calcitriol/pharmacology , Pituitary Gland, Anterior/metabolism , Thyrotropin-Releasing Hormone/pharmacology , Thyrotropin/metabolism , Animals , Cells, Cultured , Dose-Response Relationship, Drug , Drug Interactions , Female , Kinetics , Pituitary Gland, Anterior/drug effects , Prolactin/metabolism , Rats
20.
Diabetes Res Clin Pract ; 3(4): 221-6, 1987.
Article in English | MEDLINE | ID: mdl-3304910

ABSTRACT

The glycemic response following ingestion of carbohydrate in various forms is different. The factors involved are not fully elucidated. In this study the glycemic and insulin responses to 50 g of carbohydrate in the form of white bread (WB), semolina bread (SB), white spaghetti (WS) and wholemeal spaghetti (BS) were compared in ten noninsulin-dependent diabetics. The responses were assessed by calculating the area under the curve. WB and SB had significantly higher glycemic responses compared with WS and BS (P less than 0.01). There was no difference in glycemic response between either form of bread, or either type of spaghetti. Similarly WB and SB had greater insulin responses than WS and BS (P less than 0.05). There was no difference in insulin response between WB and SB but BS had a greater response than WS (P less than 0.01) attributed to the higher protein content of BS. Thus, in this study the physical form of the food was a major factor influencing the glycemic response, and other factors such as particle size and fibre content had negligible effects.


Subject(s)
Blood Glucose/metabolism , Bread , Diabetes Mellitus, Type 2/blood , Dietary Carbohydrates/administration & dosage , Food , Insulin/blood , Adult , Aged , Female , Humans , Male , Middle Aged
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