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I Tulloch

Publications and source records attributed to I Tulloch.

11 recordsLinked to original sources
PubMed1997

The influence of familial factors on the progression of IgA nephropathy.

BACKGROUND: Vascular risk factors in first degree relatives of patients with insulin dependent diabetes mellitus are known to increase the risk of that patient developing diabetic nephropathy. We explored the influence of vascular risk factors in first degree relatives on patients with stable (serum creatinine < 150 mumol/l for > 5 years) and progressive (serum creatinine > 200 mumol/l, and > 150% serum creatinine at presentation, after minimum follow-up at 2 years) IgA nephropathy (IgAN). METHODS: We compared sodium-lithium countertransport activity (SLC Vmax), plasma lipoprotein(a) and von Willebrand factor (vWf) concentrations, incidence of vascular disease, and incidence of hypertension in 37 first degree relatives of 23 patients with stable IgAN and 33 first degree relatives of 17 patients with progressive IgAN. The two groups of relatives were comparable with respect to other risk factors: age, smoking, blood pressure, and plasma glucose, creatinine, cholesterol and triglyceride concentrations. RESULTS: SLC Vmax was higher in relatives of stable patients (mean 0.37 mmol/h/l RBC [S.D. 0.18] vs 0.30 [S.D. 0.09]; P = 0.034 two-sample t-test). There was no difference between the relatives of stable and progressive patients in plasma lipoprotein(a) concentration (median 11.5 mg/l vs 13.0: P = 0.45; 95% C.I. -12 to 3; Mann-Whitney test), plasma vWf concentration (149.4 IU/dl [S.D. 55.6] vs. 163.2 IU/dl [S.D. 57.3]; P = 0.31 two-sample t-test), or incidence of hypertension (13/37 [35.1%] vs 10/33 [30.3%]; chi 2 = 0.185; P = 0.667). Relatives of patients with progressive IgAN had a slightly higher incidence of vascular disease (10/33 [30.3%] vs 8/37 [21.6%]; chi 2 = 0.688; P = 0.407). CONCLUSIONS: Familial vascular risk may increase the likelihood of progressive renal failure in patients with IgAN but the influence is likely to be small and unrelated to the factors we measured. SLC Vmax was significantly higher in relatives of patients with stable disease which contrasts with data from other studies and is unexplained.

Adult↗
PubMed1996

An investigation of the mechanism responsible for fluoxetine-induced hypophagia in rats.

The effect of fluoxetine on feeding in p-chlorophenylalanine (PCPA) pretreated rats and the nature of its interaction with 5-HT2C receptors have been investigated. Animals that received 3 days PCPA (150 mg/kg i.p.) pretreatment and vehicle on the test day consumed a similar amount as control, saline pretreated animals under the test paradigm used in this study. Fluoxetine (20 and 30 mg/kg p.o.) significantly reduced food intake in PCPA and control pretreated animals to a similar extent, despite an approximately 90% reduction in the levels of brain 5-hydroxytryptamine (5-HT) and 5-hydroxyindole acetic acid (5-HIAA) in the PCPA-pretreated animals. Thus, hypophagia is unlikely to be caused by inhibition of 5-HT reuptake. In the pig choroid plexus in vitro, fluoxetine and norfluoxetine inhibited specific [3H] mesulergine binding with pKI's (+/- S.E.M.) of 6.45 +/- 0.09 (n = 4) and 6.05 +/- 0.05 (n = 3), and slope factors (+/- S.E.M.) of 1.06 +/- 0.14 and 0.99 +/- 0.13, respectively. In slices of piglet choroid plexus fluoxetine (1, 10 and 33 microM) caused a rightward shift in the dose-response curve produced by 5-HT with no effect on the maximal response, and a mean pKB of 5.94 +/- 0.09. Norfluoxetine (10 microM) also produced a rightward shift in the 5-HT dose-response curve with no effect on the maximal response, and a pKB of 6.20. Thus, both compounds acted as surmountable antagonists with no agonist efficacy at 5-HT2C receptors present in choroid plexus. The hypophagic effect of fluoxetine (20 mg/kg p.o.) was also unaffected by the non-specific 5-HT2C receptor antagonist metergoline (2 and 5 mg/kg i.p.). These findings suggest that the hypophagic effect of fluoxetine is not likely to be dependent upon intact brain 5-hydroxytryptaminergic presynaptic function, nor is it mediated by an agonist action at the 5-HT2C receptor, but by an additional, unknown mechanism.

Animals↗
PubMed1994

Evening primrose oil reduces urinary calcium excretion in both normal and hypercalciuric rats.

Hypercalciuria is an important risk factor in the aetiology of idiopathic urolithiasis and many treatment modalities in clinical practice are directed towards reducing urinary calcium excretion. There are no natural animal models of hypercalciuria, such as the spontaneous hypertensive rat; however, the streptozotocin-diabetic rat is accepted as a good model for studies of disordered renal function associated with diabetes mellitus. Hypercalciuria is a prominent feature of the streptozotocin-diabetic rat and the model was, therefore, used to study the influence of evening primrose oil on urinary calcium excretion. Twenty rats divided into two groups of ten rats each were maintained on either normal rat chow (group 1) or primrose oil enriched diet (group 2) for 10 weeks. At 4 weeks both groups of rats were made diabetic with streptozotocin. Urine calcium measurements were serially performed before commencement of the diet, during the pre-streptozotocin (pre-diabetic) phase and during the post streptozotocin (diabetic) phase. The urine calcium excretion was significantly less in the primrose oil fed animals during both the pre-diabetic phase and the diabetic phase compared with the rats on the normal rat chow. These results indicate that evening primrose oil, a rich source of gamma-linolenic acid, helps to reduce urine calcium excretion in normal animals as well as in the hypercalciuric streptozotocin-diabetic rat. Dietary modifications with long-chain omega-6 and omega-3 fatty acids might be a useful adjunct in the treatment of idiopathic hypercalciuric urolithiasis.

Animals↗
PubMed1993

Evidence that chronic administration of paroxetine or fluoxetine enhances 5-HT2 receptor function in the brain of the guinea pig.

The effects of chronic treatment with antidepressants on 5-HT-stimulated hydrolysis of phosphoinositide (PI) in the cerebral cortex of the guinea pig were examined. The pharmacological profile of the response was consistent with it being mediated by a 5-HT2 receptor. Chronic (but not acute) treatment with the selective 5-HT uptake inhibitors, paroxetine and fluoxetine (10 mg/kg, p.o., for 21 days), resulted in a significant increase in the maximum response to 5-HT without altering the EC50. There were no significant alterations in the density or affinity of 5-HT2 receptors, labelled with [3H]ketanserin. In contrast, treatment with the tricyclic antidepressant, amitriptyline (10 mg/kg, p.o., for 21 days), did not produce a significant change in 5-HT-stimulated hydrolysis of PI or in the number and affinity of 5-HT2 receptors. The findings are discussed in relation to the possible neurochemical targets for antidepressant drugs and species differences in the responses to these agents.

Amitriptyline↗
PubMed1988

Effect of maternal ketorolac administration of platelet function in the newborn.

Ketorolac is a potent analgesic agent with antiplatelet properties which is known to cross the placenta. The aim of this study was to determine whether maternal administration of ketorolac in labour had any effect on neonatal platelet function as compared with maternal administration of pethidine and prochlorperazine. Eighteen parous women were studied in labour, twelve received pethidine (control) and six received ketorolac for analgesia. Immediately after delivery, blood was taken from the umbilical vein and anticoagulated with citrate. Platelet aggregation in whole blood was studied. Ketorolac significantly inhibited aggregation in response to arachidonic acid and collagen but not ADP. These findings confirm that ketorolac crosses the placenta. The antiplatelet effects are likely to be related to ketorolac's inhibitory effect on TxA2 production which is required for arachidonic acid and collagen-induced aggregation, but not the primary aggregation response induced by ADP. These effects suggest that ketorolac should be used with caution in patients whose neonates are at risk of haemostatic problems.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1983

Changes in the glomerular capillary wall induced by lymphocyte products and serum of nephrotic patients.

This study demonstrated that a soluble factor derived from patients with nephrotic syndrome caused changes consistent with the development of proteinuria when infused into the renal artery of a rat. The supernatants of cultures of stimulated lymphocytes of patients with the nephrotic syndrome containing autologous sera were infused into the renal arteries of rats and caused patchy spreading of the foot processes of epithelial cells and reduction of charge of the glomerular basement membrane of rat kidneys. The equivalent supernatants from normal subjects did not produce these changes.

Animals↗