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Biomedical subjects

M Whitty

Publications and source records attributed to M Whitty.

6 recordsLinked to original sources
PubMed2001

Age/sex/location: uncovering the social cues in the development of online relationships.

Past research on online relationships has predominantly been concerned with how the quality of online relationships compares with offline relationships. This research has been more concerned with the medium itself than with the meanings that users construct around their interpersonal interactions within this medium. The current paper seeks to redress this imbalance by exploring the ways that available social cues are used to shape the meanings of online relationships. Sixty Internet users, ranging in age from 19-51 years, were interviewed about their online relationships. It was found that ideals that are important in traditional relationships, such as trust, honesty, and commitment are just as important in online relationships; however, the cues that signify these ideals vary.

Adolescent↗
PubMed1992

Systemic and renovascular hypertension.

To ascertain the contribution of systemic hypertension in the progression of renal failure, we have studied the effects of pharmacological treatment of hypertension in rats with the remnant kidney model of renal insufficiency, streptozotocin diabetes, or nephrotoxic serum nephritis. Treatment with the angiotensin converting enzyme (ACE) inhibitor enalapril lowered systemic blood pressure in the remnant kidney and diabetic animals, but did not lower blood pressure in rats with nephrotoxic serum nephritis. Proteinuria was reduced in all three models, and creatinine clearance improved in the remnant kidney and diabetic animals, when compared with untreated controls. In the remnant kidney and diabetic models systemic blood pressure was lowered to a similar degree by treatments with a calcium blocker, with no improvement in either proteinuria, or glomerular filtration rate. Further studies of the long-term effects of enalapril have been undertaken in rats with the two kidney one clip model of hypertension. Rats treated with enalapril had a lower blood pressure and improved survival over one year of treatment, compared with untreated rats. After 1 year of treatment however the clipped kidney was small and fibrotic, and non functional. Following withdrawal of enalapril therapy there was no functional improvement of the clipped kidney. The possibility that ACE inhibitors have a specific intra-renal effect reducing the rate of progression of renal disease now needs confirmation in human studies. In renovascular hypertension however, intra-renal changes induced by ACE inhibitors may cause irreversible renal damage.

Animals↗
PubMed1987

Preservation of renal structure and function in the rat remnant kidney model of chronic renal failure by enalapril treatment.

The remnant kidney model of chronic renal failure was established in rats subject to subtotal (1 7/8) nephrectomy and the evolution of renal injury studied over a period of 6 wk. One wk after subtotal nephrectomy, rats had a mean conscious systolic blood pressure of 158 +/- 5 mm Hg and serum creatinine of 128 +/- 9 mumol/l. Both systolic blood pressure and serum creatinine rose over the next 5 wk in concert with progressive glomerulosclerosis and proteinuria. Enalapril, an angiotensin converting enzyme inhibitor, was administered (5 mg/kg/day) to rats (n = 11) from 1 wk after subtotal nephrectomy. Enalapril lowered systolic blood pressure over the treatment period. Systolic blood pressure was 122 +/- 5 mm Hg compared with 176 +/- 7 mm Hg in untreated rats (p less than 0.001) at 6 wk. Serum creatinine 6 wk after subtotal nephrectomy was 110 +/- 9 mumol/l with enalapril treatment, compared with 159 +/- 21 mumol/l (p less than 0.025) in control animals. Enalapril treated rats had lower urinary protein excretion than controls (15 +/- 3 mg/24 hr vs 85 +/- 22 mg/24 hr, p less than 0.0001) at 6 weeks. Glomerulosclerosis, assessed by blinded histological score, was also reduced in the enalapril treated group (1.79 +/- 0.08 vs 2.36 +/- 0.16, p less than 0.01). Enalapril treatment was associated with a reduction in filtration fraction (51Cr-EDTA/125I-hippurate clearance). At 6 wk, filtration fraction was 0.30 +/- 0.03 in enalapril treated and 0.48 +/- 0.03 in control rats (p less than 0.001). Enalapril treatment in the subtotal nephrectomy model of renal failure preserved renal structure and function.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Disparate effects of angiotensin converting enzyme inhibitor and calcium blocker treatment on the preservation of renal structure and function following subtotal nephrectomy or streptozotocin-induced diabetes in the rat.

Sprague-Dawley rats subjected to subtotal (1 7/8) nephrectomy or streptozotocin diabetes were treated with an angiotensin converting enzyme inhibitor or a calcium channel blocker and their course compared with untreated control animals. Subtotal nephrectomy led to hypertension, proteinuria, reduced creatinine clearance, and glomerulosclerosis over 6 weeks. Enalapril treatment (5 mg/kg/day, n = 11) or felodipine (30 mg/kg/day, n = 11) reduced systolic blood pressure to a comparable degree. Plasma creatinine (mumol/l) was lower after enalapril treatment (110 +/- 8, p less than 0.05) than with felodipine treatment (153 +/- 27) or no treatment (173 +/- 19, n = 18). Proteinuria (mg/24 h) was lower with enalapril treatment (15 +/- 3, p less than 0.001) than with no treatment (85 +/- 22) and increased with felodipine (221 +/- 35). Glomerulosclerosis was reduced with enalapril but not felodipine treatment. Diabetic rats were treated with enalapril (5 mg/kg/day, n = 17), verapamil (5 mg/kg/day, n = 17), or untreated. Diabetic rats had increased creatinine clearance (ml/min) compared with nondiabetic controls (1.52 +/- 0.06 vs. 1.15 +/- 0.05, n = 11, p less than 0.01). Enalapril and verapamil treatment reduced blood pressure equally. Enalapril but not verapamil reduced the elevated creatinine clearance of diabetic rats (enalapril, 1.37 +/- 0.04 ml/min, p less than 0.01; verapamil, 1.49 +/- 0.5 ml/min). Proteinuria (mg/24 h) was lower (p less than 0.05) with enalapril treatment (36 +/- 3) but not with verapamil treatment (58 +/- 10) in comparison to that in untreated diabetes (71 +/- 18).(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1986

Preservation of renal function in the rat remnant kidney model of chronic renal failure by blood pressure reduction.

The remnant kidney model of chronic renal failure was established in female Sprague-Dawley rats subjected to surgical removal of the right kidney and segmental infarction of seven-eighths of the left kidney. Plasma creatinine (mumol/l) rose from 65 (s.e.m. = 16, n = 18) to 153 (s.e.m. = 27, t-test, P less than 0.001, d.f. = 17) over 6 weeks. Histological glomerulosclerotic lesions were present from 2 weeks and prominent by 6 weeks post-surgery. Rats were treated with enalapril (5 mg/kg per day, n = 11) or felodipine (30 mg/kg per day, n = 13) from 1 week post-surgery, and their course compared to untreated rats (n = 18). Blood pressure (mmHg) was lowered by both treatments. Six weeks post-nephrectomy, systolic blood pressure in the untreated group was 176 (s.e.m. = 7, n = 18), enalapril group 122 (s.e.m. = 5, t-test, P less than 0.001, d.f. = 27), and felodipine group 128 (s.e.m. = 3, t-test, P less than 0.001, d.f. = 29). Plasma creatinine (mumol/l) was lower in the enalapril group (110, s.e.m. = 8, t-test, P less than 0.05, d.f. = 27) but not the felodipine group (173, s.e.m. = 19, t-test, n.s.) 6 weeks after subtotal nephrectomy compared to the untreated group (153, s.e.m. = 27). Glomerulosclerosis (blinded histological score) was reduced with enalapril treatment (1.93, s.e.m. = 0.03, t-test, P less than 0.05, d.f. = 27) but not felodipine treatment (2.15, s.e.m. = 0.04, c.f. untreated 2.36, s.e.m. = 0.12, t-test, n.s.). Urinary protein excretion (mg/24 h) was 84 (s.e.m. = 22, n = 13) in untreated rats, 15 (s.e.m. = 3, t-test, P less than 0.001, d.f. = 22) in enalapril-treated rats and 221 (s.e.m. = 35, n = 10) with felodipine treatment. Functional and structural damage in the rat remnant kidney model of chronic renal failure was ameliorated by treatment with enalapril but not by treatment with felodipine.

Animals↗