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Biomedical subjects

K L Lynn

Publications and source records attributed to K L Lynn.

At least 55 records · Page 3Linked to original sources
PubMed1994

Effect of hemodialysis and recombinant human erythropoietin on determinants of blood viscosity.

Blood viscosity (hemorheology) is a major determinant of the rate of blood flow, and increases in viscosity are known to be involved in the etiology of vascular diseases. This placebo-controlled study investigated the independent and combined effects of hemodialysis and recombinant human erythropoietin (rHuEpo) on determinants of blood viscosity in patients with chronic renal failure and related any changes to the normal physiological range. Hemodialysis patients were shown to have a high incidence of rheological abnormalities although the degree of anemia associated with chronic renal failure compensated for these changes. The main effect of both hemodialysis and rHuEPO treatment was an increase in hematocrit associated with a rise in blood viscosity and inconsistent changes in red blood cell (RBC) deformability. The rise in viscosity was significant only following rHuEPO treatment. Hemodialysis-induced increases in blood and plasma viscosity correlated strongly with the degree of hemoconcentration. Although hemodialysis patients have inherent hemorheological abnormalities, correction of renal anemia with rHuEPO to a hematocrit level of < 0.35 in conjunction with dialysis-induced hemoconcentration did not result in adversely high blood viscosity levels in any patient.

Anemia↗
PubMed1993

Hemorheology and fistula function in home hemodialysis patients following erythropoietin treatment: a prospective placebo-controlled study.

The beneficial effect of correcting anemia in end stage renal failure using recombinant human erythropoietin (rHuEPO) is sometimes complicated by thrombosis of the arteriovenous fistula. This placebo-controlled study investigated the relationship between hemorheological changes caused by rHuEPO and alterations in fistula function and heparin requirements in home hemodialysis patients. Erythropoietin induced a rise in high shear rate blood viscosity, a determinant of blood flow in large vessels. Doppler assessment of brachial artery blood flows, tests of fistula function and heparin requirements were similar in the two patient groups. These findings indicate that rHuEPO treatment of renal anemia resulted in the expected rise in red blood cell mass and blood viscosity although these changes did not cause problems with arteriovenous access or alter fistula function in the short term.

Adult↗
PubMed1992

Membranous nephropathy: a 19 year prospective study in 51 patients.

AIM: to study prospectively patients presenting with membranous nephropathy. METHODS: the outcome of 51 patients (33 male; mean age 50.8 SD 17.7 years; 49 caucasian, two Maori), aged 14 years and over, with membranous nephropathy was studied prospectively. The patients were enrolled between 1 July 1972 and 30 June 1991. Patients with systemic lupus erythematosus were excluded. Membranous nephropathy was secondary to drug therapy in eight (gold 3, nonsteroidal antiinflammatory drug 3, penicillamine 1, captopril 1). All patients were hepatitis B surface antigen negative. The majority of patients did not receive immunosuppressive therapy. RESULTS: forty-seven (92%) presented with the nephrotic syndrome, eight (16%) with a plasma creatinine > or = 0.15 mmol/L and 28 (55%) with hypertension. The patients were followed for a mean of 5.4 years, the median being 3.9 years and range four months-19 years. The 10 year cumulative renal survival was estimated to be 78% and overall survival 66%. Six patients have entered a renal replacement programme and six have died of nonrenal causes. Of the remaining 39, eight have renal insufficiency, 27 hypertension and 22 proteinuria. Complete remission occurred in 17 (33%)-11 spontaneously, four following withdrawal of the offending drug and two after immunosuppressive therapy. Poor prognostic indicators at presentation included renal insufficiency, need for antihypertensive therapy, pathological stage IV on renal biopsy and older age. CONCLUSIONS: membranous nephropathy is an indolent disease with a good chance of spontaneous remission. In most patients immunosuppressive treatment appears unwarranted.

Adolescent↗
PubMed1992

Comparison of ciprofloxacin with netilmicin for the treatment of acute pyelonephritis.

A prospective, randomised trial was undertaken to compare the efficacy of ciprofloxacin and netilmicin for the treatment of acute pyelonephritis. Forty-three patients were enrolled and 34 (29 women) completed the protocol. Fifteen of 17 patients treated with ciprofloxacin and 15 of 17 treated with netilmicin were cured. All patients were treated for five days. One patient relapsed after ciprofloxacin and another had a reinfection, while two relapsed after netilmicin. Five of six patients with a urinary tract abnormality were cured. Side effects were generally mild and rapidly reversible. Patients treated with ciprofloxacin spent a mean of 3.7 days in hospital compared with 5.3 days for those treated with netilmicin. The difference in duration of hospital stay was statistically significant (p less than 0.01). Both drugs proved highly effective and safe for the treatment of severe acute pyelonephritis.

Acute Disease↗
PubMed1992

Long-term followup of infants with gross vesicoureteral reflux.

The majority of children (1 year old or less) with gross vesicoureteral reflux already have renal damage at the time of presentation or reflux nephropathy develops during the first few years of life. We report the long-term followup of 31 patients (16 boys) presenting in infancy with gross vesicoureteral reflux (Rolleston classification) between 1952 and 1970. They had a total of 44 grossly refluxing ureters (13 bilateral, 18 unilateral) and presented between ages 1 day and 48 weeks (mean 15.3 weeks). Of the 31 infants 5 died within the first year of life, 4 were followed for up to 11 years before being lost to followup and 1 was killed in a motor vehicle accident after 19.5 years of followup. The remaining 21 patients have been followed for 16 to 37 years (mean 23.9 years); 4 have normal kidneys, and 13 have unilateral and 4 have bilateral reflux nephropathy. Of those patients with unilateral reflux nephropathy proteinuria, hypertension and renal failure developed in 1 born with a single kidney and he is now on hemodialysis, while 2 others have a diastolic blood pressure of 90 mm. Hg or greater. Of the 4 patients with bilateral reflux nephropathy 2 have proteinuria and renal insufficiency, with 1 progressing towards end stage renal failure. Infants who present with gross vesicoureteral reflux within the first year of life appear to do well if free of severe bilateral reflux nephropathy at presentation. Patients with reflux nephropathy should remain under regular nephrological supervision with particular attention given to proteinuria, renal function and blood pressure.

Female↗
PubMed1992

The effect of celiprolol on glomerular filtration rate and renal blood flow in patients with chronic renal impairment and healthy volunteers.

A double-blind, placebo controlled study investigated the effects of celiprolol, 200 mg daily for 7 days, on glomerular filtration rate (GFR) and estimated renal blood flow (ERBF) in eight healthy volunteers and eight patients with chronic renal insufficiency. In healthy volunteers the mean difference in GFR was 4.8 ml min-1 (95% CI -8.2 to 17.7 ml min-1) and the mean difference in ERBF was 49.8 ml min-1 (95% CI -47.5 to 147 ml min-1) after celiprolol. In patients with chronic renal insufficiency the mean difference in GFR was -2.1 ml min-1 (95% CI -64.6 to 65.8 ml min-1). The study had sufficient power to detect a 15% change in GFR for normals and 10% for patients, and for ERBF, changes of 14% and 23% were detectable. Celiprolol at a dose of 200 mg daily for 7 days can be used in patients with chronic renal insufficiency without adversely affecting GFR or ERBF.

Adolescent↗
PubMed1991

Long term complications following renal transplantation.

The long term complications of renal transplantation were assessed in 36 patients who had lived for 10 or more years with a functioning renal transplant. Thirty-three patients were alive with a mean plasma creatinine of 0.13 mmol/L (SD 0.07). A 62 year old women died from a myocardial infarction 11 years after transplantation and two women developed chronic rejection and returned to dialysis after 17 years. Nineteen patients have required antihypertensive therapy, five have suffered ischaemic heart disease and two a cerebrovascular event. Malignancy has developed in 13 patients, with four having two or more organs involved. Skin cancers (9 squamous cell, 4 basal cell) were present in all 13 patients and recurred in six. The other malignancies included carcinoma of cervix (2), cervix and bladder (1) and thyroid (1). Three patients have required parathyroidectomy for autonomous hyperparathyroidism, two splenectomy for hypersplenism, and one bilateral hip replacement for avascular necrosis of the femoral heads. The development of hypertension, vascular disease and malignancy are the most important long term complications after renal transplantation. Strategies must be formulated to reduce the morbidity and mortality from these causes.

Adult↗
PubMed1990

Wegener's granulomatosis with renal involvement: a 14 year experience.

Over a 14 year period 17 patients (nine men) with Wegener's granulomatosis and renal involvement had a renal biopsy. All patients had a necrotising glomerulonephritis and 15 had evidence of crescent formation in glomeruli. Fourteen patients were treated with both prednisone and cyclophosphamide and three with prednisone and azathioprine. The five year patient survival rate was 73% and the renal survival rate 68%.

Adult↗
PubMed1990

The pharmacokinetics and pharmacodynamics of quinapril and quinaprilat in renal impairment.

1. The pharmacokinetics and pharmacodynamics of quinapril and its active metabolite quinaprilat were studied in 20 subjects with renal function varying from normal to severe renal failure, during the approach to and at steady-state, and for 72 h after cessation of quinapril 20 mg orally for 7 days. 2. The apparent oral plasma clearance of quinaprilat (dose of quinapril equivalent/AUC of quinaprilat) was directly related to creatinine clearance (CLCr). The predicted apparent oral clearance of quinaprilat was zero when CLCr was zero, suggesting minimal extrarenal elimination. 3. Peak and trough concentrations of quinaprilat, and its apparent elimination half-life, varied inversely with CLCr. 4. Trough concentrations of quinaprilat showed no accumulation between 2 and 7 days, even in severe renal impairment. 5. There was a weak relationship between the oral plasma clearance of quinapril and CLCr. 6. ACE inhibition was marked and prolonged in all subjects, with 50% inhibition at 2.7 +/- 1.9% ng ml-1 of quinaprilat. The time for which ACE inhibition was greater than 90% was related inversely to CLCr. 7. Aldosterone concentrations and plasma renin activity responded in a predictable way, but with no clear relationship To CLCr. 8. Atrial natriuretic peptide concentrations were not affected by quinapril administration. 9. Glomerular filtration rate, as measured by Tc99mDTPA clearance, was not affected by quinapril administration. 10. Blood pressure at steady-state decreased significantly in the subjects with hypertension. The changes in blood pressure were not related to renal function. 11. These results suggest that the dosage rate of quinapril may have to be altered in renal impairment.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗
PubMed1990

Disseminated prostatic carcinoma presenting with acute interstitial nephritis and microangiopathic haemolytic anaemia.

A 74-year-old man with metastatic prostatic carcinoma developed acute oliguric renal failure, a microangiopathic haemolytic anaemia and thrombocytopaenia. A renal biopsy showed an acute interstitial nephritis but no changes suggestive of the haemolytic uraemic syndrome. He recovered normal renal function after treatment with haemodialysis and prednisone 20 mg daily for five days. Previous assumptions about the renal lesion in patients with malignancy-associated microangiopathic haemolytic anaemia may need review.

Acute Disease↗
PubMed1990

Anemia and angiotensin-converting enzyme inhibition in renal transplant recipients.

The renin-angiotensin system has been shown to have an effect on erythropoietin synthesis and hemoglobin concentration. We present a retrospective study of stable renal transplant recipients who received an angiotensin-converting enzyme (ACE) inhibitor as treatment of hypertension. Fifteen patients were eligible, with a mean hemoglobin concentration of 130.7 +/- 22.7 g/L (SD). Within 6 months of ACE-inhibitor therapy, the mean hemoglobin had fallen significantly to 110.5 +/- 23.2 g/L (p less than 0.001). No parallel change in leukocyte or platelet counts was evident. Prospective studies are needed to clarify the effect of inhibition of the renin-angiotensin system on erythropoietin synthesis and release.

Anemia↗
PubMed1990

Red cell volume distribution curves in the diagnosis of glomerular and non-glomerular hematuria.

It has been suggested that measurement of red blood cell (RBC) volume, by red cell analyzers (RCA), may be used to distinguish glomerular from non-glomerular hematuria. The RCA measures all urinary particles, including RBC. We found that red cell volume distribution curves (RVDC) obtained with a Coulter S+IV RCA were non-specific in predicting the cause of hematuria. Normal RBC added to urine at about 15,000/mm3 produced the expected non-glomerular RCVDC but at decreasing RBC concentrations mixed and then glomerular RCVDCs were found. Urine from 7 normal subjects (6 without urinary RBC) showed particle volume distribution curves identical to glomerular RCVDC. These urinary particles were examined by scanning electron microscopy (SEM) after filtration (3 microns and 0.8 micron pore size). Hematuric urine from a patient after prostatectomy contained RBC (3.5-9.5 microns diameter) and particulate debris (1.0-7.5 microns diameter). Similar results were obtained for a patient with crescentic glomerulonephritis (particles 1-13 microns diameter). Attempts to separate glomerular urinary RBC from debris by centrifugation against a sucrose polymer were unsuccessful. The shape of the RCVDC obtained with RCA is altered by the presence of debris in urine. The true MCV of glomerular RBC is still unknown. The usefulness of RCA in the diagnosis of hematuria is limited to patients with large numbers of urinary RBC.

Adult↗
PubMed1989

Nutritional status of home hemodialysis patients.

We studied the nutritional status of 32 patients (23 men), aged 50 (SD14) yr, on home hemodialysis (HHD) for one-138 months. No formal dietary restrictions were imposed. Anthropometric measurements were made using standard techniques, diet assessed by three-day dietetic diary and interview and plasma concentrations of nutrients were measured. Mean caloric intake was 29.4 (SD 10.7) kcal/kg; 24 (75%) patients had lower energy intakes than recommended for normals. Protein, vitamin C and folate intakes were above recommended minimum safe intakes. Intakes were less than recommended for calcium in four (13%) patients, iron in one (3%) and vitamin B12 in two (6%). One-third of both sexes had body mass indices (kg/m2) less than 25th percentile for normals, but none was less than 80% of ideal bodyweight. Arm muscle circumference was less than 10th percentile for normals in six men and three women. Triceps skin fold thickness was less than 10th percentile in four men (17%) and five women (55%). No anthropometric measurements were correlated with energy, protein or fat intake. Biochemical measurements were not useful in predicting protein intake. Neither nutritional intake nor anthropometric measurements were correlated with the duration of HHD. There was little evidence of malnutrition and wasting in this group of well rehabilitated HHD patients.

Adult↗