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Biomedical subjects

M I Koolen

Publications and source records attributed to M I Koolen.

34 records · Page 2Linked to original sources
PubMed1986

Plasma lipid fractions during bopindolol treatment in hypertensive patients.

The influence of bopindolol monotherapy on blood pressure and plasma lipid fractions was investigated in 24 hypertensive patients. Bopindolol lowered blood pressure and heart rate significantly. When compared with placebo, no changes were found in the plasma concentrations of total cholesterol, low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol. Plasma triglycerides were significantly increased after 4 and 8 weeks but not after 12 weeks of bopindolol. It is concluded that bopindolol is an effective and well tolerated beta blocker in hypertensive patients. That it does not lower HDL cholesterol could be a potential advantage.

Adrenergic beta-Antagonists↗
PubMed1985

Is the renal kallikrein system relevant to sodium sensitivity in patients with essential hypertension.

In twenty-five outpatients with essential hypertension, the relevance of renal kallikrein excretion for inter-individual differences in the blood pressure response to changes in dietary sodium intake was investigated. The patients were studied during 2 weeks of high (300 mmol) and 2 weeks of low (50-100 mmol) sodium intake. In addition there were two control periods of normal sodium intake, one lasting 4 weeks at the beginning and one lasting 2 weeks at the end of the study. Blood pressure, body weight and 24 h urinary sodium and kallikrein excretion were measured at the end of all periods. At the end of the first control period, 1 mg furosemide per kg body weight was administered intravenously, and the urinary excretion of kallikrein and sodium were measured 30 and 120 min later. The difference in mean arterial pressure (delta MAP) between high and low sodium intake ranged from + 18 to -8 mmHg. The eight patients with a delta MAP greater than 10 mmHg were regarded as salt-sensitive. They were older and had a higher initial blood pressure than salt-insensitive patients. For all patients, urinary kallikrein excretion at the end of the low sodium period (123(SEM 20.3) micrograms 24 h-1) was significantly higher than at the end of the first control period (96(SEM 16.3) micrograms 24 h-1, P less than 0.01) and at the end of the high sodium period (96(SEM 23.7) micrograms 24(-1), P less than 0.01). When compared with salt-insensitive patients, salt-sensitives had lower levels of urinary kallikrein excretion and a blunted kallikrein response to dietary sodium restriction and furosemide.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Sodium sensitivity in essential hypertension: role of the renin-angiotensin-aldosterone system and predictive value of an intravenous frusemide test.

In order to determine factors contributing to sodium induced changes of blood pressure, 20 patients with essential hypertension were studied when on their regular sodium intake and after two weeks of a low sodium diet (50 mmol daily) and two weeks of a high sodium diet (300 mmol daily). There were two periods of regular sodium intake, one of four weeks at the beginning and one of two weeks at the end of the study. The change in mean arterial pressure between the high and low salt diets (delta MAP) was regarded as a measure of sodium sensitivity, and was directly correlated with age and initial blood pressure. Compared with non-responders, responders (delta MAP 10 mmHg or more) showed a lesser activation of the renin-angiotensin-aldosterone system during the low salt period. The response to the administration of intravenous frusemide was not helpful in predicting sodium sensitivity. A significant but relatively small (4.2 mmHg) reduction in MAP was obtained during low salt period compared with the first period of regular sodium intake. The data suggest that moderate dietary sodium restriction can help to reduce the blood pressure of the relatively older patient with hypertension.

Adult↗
PubMed1984

Excretion of urokallikrein in renal transplant patients. Relation to graft rejection, renal function, and blood pressure.

The relation between urinary kallikrein excretion ( Ukal ) and rejection, graft function, and blood pressure was studied in 45 renal transplant recipients. Ukal was assayed by means of an enzymatic (amidolytic) method, as well as with a specific radioimmunoassay. In a group of 10 patients studied longitudinally from the day of transplantation till day 35 +/- 3, an increase in urinary amidolytic activity without a concomitant increase in kallikrein antigen excretion was found to precede 11 out of 14 rejection episodes. This increased amidolytic activity generally persisted for several days. It was demonstrated by chromatography using an immunoadsorbent column of antiurokallikrein that the rejection-associated esterase, or esterases, differed from urokallikrein . In 35 outpatient recipients with stable graft function, Ukal excretion was decreased compared with that of healthy controls (42 +/- 7.5 vs. 107.5 +/- 7.3 micrograms/24 hr by radioimmunoassay and 0.70 +/- 0.08 vs. 1.10 +/- 0.07 U/24 hr, using the amidolytic method); for these patients a significant correlation between Ukal excretion and creatinine clearance was found (P less than 0.02). Both in transplant recipients and in controls there was a close correlation between the results of the two Ukal assays (P less than 0.001). No significant relation between Ukal excretion and blood pressure was found, either for patients or for controls. It is concluded that acute graft rejection is accompanied by an increased excretion of nonurokallikrein esterase(s). The lower Ukal excretion in patients with stable renal function seems to be related to their reduced renal function. No relation between Ukal excretion and blood pressure levels was found.

Adolescent↗
PubMed1984

Plasma lipid fractions during long-term monotherapy with the ISA-containing beta-adrenoceptor blocker bopindolol in hypertensive patients.

The influence of bopindolol monotherapy on blood pressure and plasma lipid fractions was investigated in 24 hypertensive patients. Bopindolol lowered blood pressure and heart rate significantly. When compared with placebo no changes were found in the plasma concentrations of total cholesterol, LDL cholesterol and HDL cholesterol. Plasma triglycerides were significantly increased after 4 and 8 weeks but not after 12 weeks of bopindolol. It is concluded that bopindolol is an effective and well tolerated beta-adrenoceptor blocker in hypertensive patients. The fact that it does not lower HDL cholesterol could be a potential advantage.

Adult↗
PubMed1984

Direct and indirect measurement of urinary kallikrein excretion in patients with essential hypertension and normotensives: relation to age and plasma renin and aldosterone levels.

The relevance of age and activity of the renin-angiotensin-aldosterone system to the excretion of urinary kallikrein (Ukal) was studied in twenty-five patients with essential hypertension and forty normotensive controls. The age range for both study groups was 20-60 years. Ukal was measured by radioimmunoassay and by an amidolytic assay. Results of both assays correlated closely (r = 0.93, n = 65, P less than 0.001). For all hypertensives Ukal excretion was not significantly different from that of controls. However, older hypertensives (greater than 40 years, n = 13) had a significantly lower Ukal excretion than normotensives of the same age (n = 20) (radioimmunoassay 67.2 (SEM 7.2) v. 105.1 (SEM 8.4) micrograms (24 h)-1; and amidolytic method 0.84 (SEM 0.10) v. 1.13 (SEM 0.08) U (24 h)-1). No correlation was found between Ukal excretion and plasma renin or aldosterone. In fact, the aldosterone level was highest in older hypertensives. In conclusion, the lower Ukal excretion in hypertensives over 40 is likely to be secondary to the long-standing high blood pressure. Under basal conditions, Ukal excretion seems little influenced by the activity of the renin-angiotensin-aldosterone system.

Adult↗
PubMed1983

Clinical biochemical and haemodynamic correlates of sodium sensitivity in essential hypertension.

Factors contributing to the blood pressure (BP) response to changes in dietary sodium intake were studied in 25 patients with essential hypertension (EH). Relevant clinical, biochemical and haemodynamic variables were measured after two weeks on a low sodium diet (LS, 50 mmol) and after two weeks on a high sodium diet (HS, 300 mmol). BP was significantly higher during HS. The difference in mean arterial pressure between HS and LS (delta MAP) was taken as a measure of sodium sensitivity. delta MAP was directly related to age, initial BP, plasma noradrenaline during HS and changes in forearm vascular resistance. It was indirectly related to plasma aldosterone during LS. No correlation was found with renin or with the excretion of urinary kallikrein. It is concluded that sodium sensitivity in EH is related to age and blood pressure and is predominantly mediated by changes in vascular resistance to which aldosterone and adrenergic mechanisms are likely to contribute.

Adult↗
PubMed1980

Less aggressive rejection therapy and low-dose corticosteroids leading to satisfactory cadaveric kidney graft survival and low morbidity rate.

A less aggressive approach in treatment of rejection crises has been introduced since January 1979. Findings in 39 patients demonstrate that rejection treatment can be started later and be applied with considerably less frequency without an increase in graft loss. A reduction of more than 50% in corticosteroid dosage applied within three months after transplantation seems to be possible, with a sharp decrease of morbidity rate.

Cadaver↗
PubMed1979

Immune complex glomerulonephritis in chronic granulomatous disease. Case report of an eighteen-year-old girl.

An 18-year-old girl is described who developed advanced renal sclerotic lesions, probably preceded by local focal glomerulonephritis, which coexisted with a Staphylococcus aureus abscess. It is hypothesized that immune complex glomerulonephritis developed, provoked by long-term antigenic stimulation of Staphylococcus aureus. The cause of these long-term bacterial infections was a defect of the phagocytic cells to kill bacteria effectively, a disease known as chronic granulomatous disease. Therapy with intracellularly active antimicrobial agents restored the renal function till no more haemodialysis was necessary.

Adolescent↗
PubMedDate not supplied

Hematogenous Candida vertebral osteomyelitis treated with ketoconazole.

Candida vertebral osteomyelitis was diagnosed in a patient with systemic lupus erythematodes following X-ray evidence of osteomyelitis and the repeated culturing of Candida albicans from material obtained by needle biopsies from the third lumbar vertebra. The patient had been on glucocorticosteroids and parenteral nutrition six months previously. At that time, a yeast was cultured from the blood and the tip of the subclavian catheter which had been removed. After candida vertebral osteomyelitis was diagnosed, she was treated with ketoconazole for seven months. Recovery was impressive, as judged by the clinical and radiographic findings. At the time of writing this paper--12 months after the withdrawal of ketoconazole--the patient showed no signs of recurrence.

Adult↗
PubMedDate not supplied

Adrenergic activity and peripheral hemodynamics in relation to sodium sensitivity in patients with essential hypertension.

In 25 outpatients with essential hypertension, sodium sensitivity, defined as the difference in mean arterial pressure (delta MAP) between 2 weeks of high-sodium (300 mmol per day) and 2 weeks of low-sodium (LS) intake (50-100 mmol per day), was studied in relation to the plasma norepinephrine (NE) level, NE release, and pressor response to intravenous NE. In addition, forearm blood flow (FBF) was measured by plethysmography. There were two control periods of regular sodium intake, one of 4 weeks' duration at the beginning of the study and one of 2 weeks' duration at the end. The delta MAP ranged from +18 to -8 mm Hg. The eight patients in whom delta MAP was greater than 10 mm Hg were regarded as salt-sensitive. When compared with salt-insensitive subjects, salt-sensitive patients had higher plasma NE levels in the control period (p less than 0.05) and after 2 weeks of HS intake (p less than 0.01). Sodium sensitivity was directly related to the change in plasma NE between the HS and LS periods (p less than 0.001). The NE release decreased in salt-insensitive subjects whereas it increased in salt-sensitive patients between the LS and HS periods. Changes in NE release were directly related to sodium sensitivity (p less than 0.05). The pressor response to NE was not significantly influenced by changes in sodium intake. The FBF fell in salt-sensitive patients and increased in salt-insensitive subjects between the LS and HS periods. Sodium sensitivity was directly related to the change in forearm vascular resistance (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Vascular complications in 400 consecutive renal allotransplants.

The vascular complications, their management and results of treatment in 400 consecutive renal allotransplants performed at the Leiden University Hospital from March 1966 through July 1979, are presented. There were 50 (12.5%) vascular complications. Among them renal artery stenosis (RAS) occurred in 40 cases (10%), renal artery thrombosis in 7 cases (1.8%), renal vein thrombosis in 2 cases (0.5%) and disruption of the arterial anastomosis in one. Arterial reconstruction was made in 25 patients with RAS, the blood pressure was normalized in 18 patients (72%), in 3 a recurrence of the RAS was found, in another 3 bad results were achieved regarding the blood pressure and in one patient a recurrence of the original glomerulonephritis had taken place. Of the 50 vascular complications 12 patients underwent a removal of the transplant and 3 resulted in death of the patient.

Adolescent↗
PubMedDate not supplied

Nasal carriage and peritonitis by Staphylococcus aureus in patients on continuous ambulatory peritoneal dialysis: a prospective study.

OBJECTIVE: To establish whether or not patients on continuous ambulatory peritoneal dialysis (CAPD) using current infection control measures who are nasal carriers of Staphylococcus aureus are at risk for the development of S. aureus peritonitis. DESIGN: A prospective 22-month study analyzing nasal and skin/nasal (i.e., nasal and/or exit-site) carrier status for S. aureus and peritonitis episodes. Nasal swab cultures for S. aureus were taken with 1- to 3-month intervals; swab cultures from the catheter exit site were taken only when infection was suspected. SETTING: Renal unit, tertiary-care center. PATIENTS: All patients on CAPD at our center that could be observed during at least 2 months. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Nasal and skin/nasal carrier status, occurrence of peritonitis. RESULTS: Of 54 enrolled patients, 31 (57%) were nasal carriers for S. aureus: 6 of these 31 developed S. aureus peritonitis as opposed to none of 23 non-carriers (p = 0.03). The S. aureus peritonitis rate in 28 skin/nasal carriers was increased when compared to non-carriers (p = 0.02), but there was no difference between chronic and intermittent skin/nasal carriers (p = 0.63). CONCLUSIONS: In our population, nasal carriers are at increased risk for the development of S. aureusperitonitis. Further studies should evaluate the effect of eradication of nasal carriage of S. aureus and the effect of additional preventive hygienic measures on the occurrence of peritonitis by S. aureus.

Female↗