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Biomedical subjects

I Nielsen

Publications and source records attributed to I Nielsen.

At least 73 records · Page 4Linked to original sources
PubMed1982

Hypospadias repair: with construction of a fossa navicularis.

Acceptable results can be achieved in the treatment of hypospadias by the use of Denis Browne's method. However, the condition is not completely normalized, as the external orifice of the urethra is most frequently situated in the neighbourhood of the coronal sulcus and the orifice itself open. The distance to the normal urethral mucosa is thus short with the consequent increased risk of contamination. In order to ensure normalization of the condition, Denis Browne's method was supplemented by the construction of a fossa navicularis in 74 patients with hypospadias. The results of this construction were satisfactory in the great majority of cases.

Adolescent↗
PubMed1981

Anti-IgG antibodies and antinuclear antibodies in allergic patients.

With an indirect immunofluorescence technique 77% of 96 patients with type I allergy and 40% of 20 patients with intrinsic bronchial asthma showed positive reactions for IgG anti-IgG antibodies in serum. They were present partly in an aggregated state not directly detectable before treatment with dithiothreitol. The aggregates could be removed by precipitation with polyethylene glycol. The IgG anti-IgG in hyposensitized patients were directed against both F(ab')2 and Fc fragments of rabbit IgG. Thirty of the type I allergic patients were examined once during hyposensitization as well. Before treatment 87% had IgG anti-IgG (titres 9-72). After greater than or equal to 13 months of treatment 100% were positive (titres 36-288). Eight patients were also examined after hyposensitization had been discontinued for at least 12 months. The titres of IgG anti-IgG had then reverted to the levels obtained before hyposensitization. Of 116 controls matched for sex and age, 7% had IgG anti-IgG antibodies. It is suggested that the production of IgG anti-IgG may be stimulated by the presence of immune complexes and that purity, amount and/or combination of allergens administered during hyposensitization may influence the production of anti-IgG antibodies. Neither IgE anti-IgG nor antinuclear antibodies seem to be of particular significance in allergic patients.

Adolescent↗
PubMed1979

The relationship of urinary prostaglandins and plasma renin to sodium balance and diuresis in normal man.

The significance of changes in sodium balance and urinary sodium excretion for renal PG excretion was studied in normal man. In protocol B a strongly negative sodium balance was produced in 5 healthy young subjects by a low sodium diet given for 7 days (lo mmol Na/day) with 80 mg furosemide p.o. added on the last two days. 24 hour urinary PGE2 excretion remained constant, while plasma renin increased. In protocol A the effect of i.v. furosemide (1 mg/kg bwt) on urinary PGE2 and PGF2 alpha excretion rates was examined in 5 healthy young subjects. Rapid but short-lasting increases in PG excretion rates ran in parallel with the changes in urine flow rate. The study suggests that PGE2 is not of importance for the sodium homeostasis in normal man. Renal prostaglandins may play a modifying role for the renal response to loop diuretics but are hardly instrumental for the diuretic effect.

Adult↗
PubMed1979

Sodium balance, urinary prostaglandin E2 and renin in normal man.

1. Urinary prostaglandin (PG) E2 excretion and plasma renin were measured in five healthy volunteer subjects for 2 h after intravenous injection of frusemid (protocol A) and during salt restriction for 7 days with frusemide added on the 2 last days (protocol B). 2 In protocol A, peak values in PGE2 and urine flow were reached in 10-20 min, after which the values rapidly subsided. Plasma renin increased twofold in 60 min. 3. In protocol B, even during severe antinatriuresis (day 5) and during maximal negative sodium balance (day 7), no change in urinary PGE2 excretion was observed. Plasma renin increased twofold on day 5 and increased tenfold on day 7. 4. The result of protocol B does not suggest any essential role of renal PGE2 for sodium excretion or sodium homeostasis in man. The result of protocol A may point to a role of renal prostaglandins for the diuretic action of frusemide.

Adult↗
PubMed1979

On the pathogenetic role of prostaglandins in Bartter's syndrome.

Two patients, one with Bartter's syndrome and one with severe abuse of diuretics, were investigated before and after indomethacin treatment. Before indomethacin the two patients showed a similar pattern of hypokalaemic alcalosis, secondary hyperaldosteronism, and increased urinary excretion of PGE2 and kallikrein. After a few days on peroral indomethacin medication the hypokalaemia was significantly improved, the plasma renin activity, and the urinary excretion of aldosterone, PGE2 and kallikrein were normalized in both patients. It is concluded that the beneficial effect of indomethacin cannot be used as a proof of prostaglandin overproduction as the primary defect in Bartter's syndrome.

Adolescent↗
PubMed1978

The influence of acute blood volume changes on plasma renin activity in man.

The effect of an acute 10% blood volume reduction on plasma renin activity (PRA) was examined in seven patients with minor heart diseases during haemodynamic investigation and in five healthy subjects after 3 days furosemide administration. PRA was not significantly changed. Blood pressure remained constant, atrial pressures decreased. The effect on PRA of an acute 10% blood volume expansion with albumin infusion was studied in thirteen patients with liver or heart diseases. A slight reduction of PRA after albumin did not exceed the expected decrease due to plasma dilution. Blood pressure was unchanged, atrial pressures increased. Renal blood flow increased after albumin in all of the five patients investigated. The effect of PRA of an acute 10% blood volume expansion with whole blood flow increased after albumin in all of the five patients investigated. The effect on PRA of an acute 10% blood volume expansion with whole blood was then investigated in five healthy subjects, pretreated with furosemide for 3 days. A significant decrease in PRA was found. Blood pressure remained constant. It is concluded that an acute blood loss of 10% and an acute blood volume expansion of 10% with albumin have little influence on PRA in supine man, whereas an acute blood volume expansion of 10% with whole blood induces a significant PRA suppression.

Adult↗
PubMed1978

Renin stimulation by passive tilting: the influence of an anti-gravity suit on postural changes in plasma renin activity, plasma noradrenaline concentration and kidney function in normal man.

Plasma renin activity (PRA), plasma noradrenaline concentration, heart rate, blood pressure, and clearances of para-aminohippurate and inulin were measured in twelve normal subjects (clearances in only three subjects) before and after 40 min of 60 degrees upright tilting. The tilting experiments were repeated after inflation of an anti-gravity suit to 60 mmHg on the lower extremities. Inflation of the anti-gravity suit caused an abolition of the postural PRA increase, a marked reduction of the postural increases in plasma noradrenaline and heart rate, and elimination of the decreases in pulse pressure, inulin and para-aminohippurate clearances and sodium excretion. The results suggest a decisive role of the sympathetic nervous system for postural renin increase, probably mainly activated by stretch receptors in the low-pressure cardiopulmoanry area.

Adult↗
PubMed1978

Acute and long-term salt depletion and beta-blockade: plasma renin activity response and its relation to blood pressure reduction in long-term treatment.

The changes in plasma renin activity (PRA) during short-term salt depletion (and peroral furosemide on the first day) and after bolus injection of propranolol were compared to the change during long-term treatment with diuretic and with propranolol in 19 patients with benign primary hypertension. A highly significant correlation was found between PRA on short-term and long-term salt depletion (r=0.02). A highly significant correlation was likewise found between initial PRA and decrement of PRA after bolus injection of or long-term treatment with propranolol. Only a weak inverse correlation was found between PRA reached during short-term salt depletion or long-term diuretic treatment and the fall in diastolic BP during long-term treatment (r=0.60). No significant correlation was found between decrease in PRA on propranolol (bolus/long-term) and diastolic BP reduction. It is concluded that the short-term PRA response to salt depletion and propranolol in the individual patient gives a good prediction of the PRA level on long-term diuretic or propranolol treatment, but is of no value in predicting the BP reduction during treatment.

Adrenergic beta-Antagonists↗
PubMed1977

Suppression of plasma renin activity by intravenous infusion of antidiuretic hormone in man.

1. Ten patients on maintenance diuretic treatment received an intravenous infusion of antidiuretic hormone at a low rate for 1 hr. 2. A gradual reduction in mean plasma renin activity was observed and this was significant at 60 min. 3. There was a significant correlation between the initial value and the extent of the fall in plasma renin activity. There was no consistent change in blood pressure, heart rate and blood volume. 4. The results point to an intrarenal site of action of antidiuretic hormone.

Adult↗
PubMed1977

Tachycardia, hypertension and syncope. A case report.

A case of orthostatic syncope with tachycardia and hypertension is described. Initially the condition was interpreted as a dysfunction in the neurovascular orthostatic regulation, but extensive physiologic examinations failed to give a comprehensive explanation. A psychiatric examination demonstrated the condition eventually to be hysteriform and the patient was completely cured by psychotherapy.

Adult↗
PubMed1976

Unimpeded plasma renin increase after intravenous furosemide during saline replacement.

The effect on plasma renin activity of intravenous furosemide combined with saline replacement of the volume depletion was studied in twelve patients with insignificant heart disease. In ten of the patients the investigation was repeated without saline replacement. It was found that saline infusion, reducing or eliminating hemoconcentration, had no significant influence on the marked plasma renin increase. In eight of the patients the combined furosemide-saline study was performed during right-hear catheterization. Decrease in atrial pressures, known to occur within 15 min after furosemide intravenously, was virtually absent with the saline replacement. It is concluded that plasma volume reduction after intravenous furosemide is responsible for decreased filling pressures of the ventricles but not for plasma renin increase.

Adolescent↗
PubMed1976

Plasma renin activity and blood pressure during long term treatment with propranolol and diuretic.

19 primary hypertensive patients were treated in random succession with diuretic, propranolol and the combination of both. It was found that the diuretic gave a sustained increase in plasma renin activity (PRA). There was a negative correlation between PRA level attained and blood pressure reduction. Propranolol treatment gave a sustained reduction of PRA. There was no correlation between PRA reduction and blood pressure reduction. When diuretic was combined with propranolol, PRA was in average at control level, and there was no correlation between the PRA reduction from diuretic value to combination value and the corresponding additional blood pressure fall. It is concluded that propranolol treatment does not transform patients to "low renin hypertensives" specifically sensitive to diuretic treatment.

Adult↗
PubMed1976

Renal vein renin ratio. Predictive value in renal and renovascular hypertension.

Renal vein renin ratios were determined in hypertensive patients, 19 with renal artery stenosis, 7 with renal artery occlusion and 13 with unilateral renal hypoplasia. Twenty-one of these patients were treated surgically. Renal vein renin ratios of greater than or equal to 1.5 were associated with high frequency of operative success, but ratios less than 1.5 by no means excluded good surgical results.

Adolescent↗