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Biomedical subjects

H H Parving

Publications and source records attributed to H H Parving.

At least 271 records · Page 15Linked to original sources
PubMed1980

The effect of glucagon infusion on kidney function in short-term insulin-dependent juvenile diabetics.

Kidney function was studied in nine, metabolically well controlled, short-term insulin-dependent male diabetics before and during glucagon infusion of 4 to 5 and 8 to 10 ng/kg/min. Glomerular filtration rate, effective renal plasma flow (steady-state infusion technique, with urinary collections, using 125I-iothalamate and 131I-iodohippurate), and urinary albumin and beta 2-microglobulin excretion rates were measured. The mean plasma glucagon concentration increased during infusion from 254 +/- 19 pg/ml to 440 +/- 31 pg/ml (low dose) and 730 +/- 52 pg/ml (high dose). Glomerular filtration rate increased in all subjects from 133 +/- 5 before the glucagon infusion to 141 +/- 4 with the low dose, and 148 +/- 7 ml/min/1.73 m2 with the high dose (p < 0.01). The increase in glomerular filtration rate correlated with the rise in plasma glucagon concentration (r = 0.67; p < 0.01). Renal plasma flow increased from 530 +/- 21 before the glucagon infusion to 555 +/- 20 with the low dose and 572 +/- 29 ml/min/1.73 m2 with the high dose (p < 0.01). Urinary beta 2-microglobulin excretion rate rose from 5.8 +/- 1.0 before infusion to 8.7 +/- 1.7 with the low dose, and 17.9 +/- 5.7 micrograms X 10(-2)/min with the high dose (p < 0.01). Urinary albumin excretion remained unchanged during the glucagon infusion. These results suggest that glucagon may contribute to the reversible elevation of glomerular filtration rate typically found in poorly regulated insulin-dependent diabetics, but not to the moderate elevation found in well controlled diabetics.

Adolescent↗
PubMed1980

Urinary albumin and beta 2-microglobulin excretion rates in patients with systemic lupus erythematosus.

The daily urinary albumin and beta 2-microglobulin excretion rates were measured with sensitive radioimmunoassays in 14 patients with systemic lupus erythematosus (SLE). The duration of SLE ranged from 0.5 to 18 years, mean 10 years. The mean age was 37 years. All patients except 5 received prednisone, 5-20 mg/day. None of the patients had proteinuria as judged by the "Albustix" test, and all had normal serum creatinine. The daily urinary albumin and beta 2-microglobulin excretion rates were nearly the same as those previously found by us in 27 adult control subjects with a mean age of 44 years. Our study shows that SLE patients without clinical proteinuria have a completely normal renal glomerular and tubular protein handling, irrespective of the duration of the disease.

Adult↗
PubMed1980

Filtration as the main transport mechanism of protein exchange between plasma and the peritoneal cavity in hepatic cirrhosis.

Fractional peritoneal reabsorption rates (FPRR) were determined from the plasma activity after simultaneous intraperitoneal injection of 131I-labelled serum albumin (a) and 125I-labelled immunoglobulin G-IgG (g) in eight patients with cirrhosis (+ ascites 6, -ascites 2) and in one patient with carcinomatous ascites. Trans-vascular escape rates of albumin (TERa) and IgG (TERg) were determined in the cirrhotic patients from the disappearance of simultaneously intravenously injected 131I-labelled serum albumin and 124I-labelled IgG. Peritoneal space to plasma appearance times ranged 0.1-3.3 h, and the appearance times of albumin and IgG were almost identical. In patients with cirrhosis FPRRa and FPRRg were on average 1.27 and 1.21% of intraperitoneal protein masses returning to plasma per hour, respectively. Mean FPRRg/FPRRa ratio was 0.95 and this value was not significantly different from unity, but significantly higher (P < 0.001) than the ratio between the free diffusion coefficients of IgG and albumin (0.06). The calculated ascitic fluid flow rate was on average 61 ml/h. TERa and TERg were on average 9.6 and 8.6% of intravascular protein masses per hour, mean TERg/TERa ratio was 0.95. Peritoneal space to plasma protein flux averaged 0.4% of the intravascular protein mass per hour. The results point to filtration (convective flux) as the main transport mechanism responsible for protein passage into the peritoneal cavity as well as for the protein passage (lymphatic drainage) back into the plasma. Pressure measurements during catheterization confirmed pressure differences essential for convective flux.

Adult↗
PubMed1980

Filtration as the main mechanism of increased protein extravasation in liver cirrhosis.

Transvascular escape rates of albumin and immunoglobulin-G, IgG (TERalb and TERIgG, i.e, the fractions of intravascular mass of albumin and IgG passing to the extravascular space per unit time) were determined simultaneously from the disappearance of intravenously injected 131I-labelled human serum albumin and 125I-labelled human IgG in eight patients with cirrhosis of the liver. The mean wedged hepatic venous pressure was 22 mmHg (range 13-34). TERalb and and TERIgG/TERalb ratio was on average 8.4 +/- 0.8%/h (SD), and 7.4 +/- 1.9%/h (SD), respectively and these values are significantly increased compared to normal subjects [TERalb = 5.2 +/- 1.0 %/h (SD) and TERIgG = 3.0 +/- 0.7 %/h (SD), P less than 0.001]. The TERIgG/TERalb ratio was on average 0.88 +/- 0.20 (SD), which is significantly higher than that of normals [0.58 +/- 0.08 (SD), P less than 0.005]. The results indicated that increased filtration (bulk flow) is the dominant process of the increase microvascular protein escape in cirrhosis, due most likely to increased hepatic, but also to increased extrahepatic splanchnic transcapillary protein flux.

Adult↗
PubMed1979

Mechanisms of edema formation in myxedema--increased protein extravasation and relatively slow lymphatic drainage.

We assessed extravascular accumulation of albumin and fluid in primary myxedema by measuring metabolic turnover and transcapillary escape of 131I-labeled human albumin in seven patients. In the hypothyroid state, we found a low plasma volume (P less than 0.05), a reduced rate of albumin synthesis and catabolism (P less than 0.01), an increased transcapillary escape rate of albumin (P less than 0.01), a remarkable increase in the extravascular mass of albumin (1500 micronmol; P less than 0.01) and a longer mean transit time through the extravascular spaces in primary myxedema than in other states of generalized edema (P less than 0.05). All variables returned to normal during l-thyroxine treatment. The extravascular accumulation of albumin, and presumably of all other plasma proteins, is important in the generalized edema typically found in myxedema. Inadequate lymphatic drainage may also explain the formation of exudates in the serous cavities that are well known in myxedema.

Adult↗
PubMed1979

Effect of metabolic regulation on renal leakiness to dextran molecules in short-term insulin-dependent diabetics.

Renal clearance of dextran of two ranges of molecular size and glomerular filtration rate (GFR, 51Cr-EDTA) were measured in seven short-term insulin-dependent diabetics (mean age 25 years). Measurements were carried out in the same patient during good and poor metabolic regulation (plasma glucose, mean +/- SEM, 6.5 +/- 0.9 and 14.8 +/- 1.5 mmol/l, respectively). GFR was elevated in all patients during poor metabolic regulation (119 +/- 6 ml/min/1.73 m2, versus 99 +/- 2 ml/min/1.73 m2 during good control, p less than 0.01). The average renal clearance of dextran with molecular weights ranging from 25,000 to 35,000 and 35,000 to 45,000 increased during poor metabolic regulation from 14.8 +/- 0.8 to 19.8 +/- 1.8 ml/min/1.73 m2, and 5.2 +/- 0.3 to 6.8 +/- 0.6 ml/min/1.73 m2, respectively (p less than 0.05). The elevated GFR and renal dextran clearance found during poor metabolic regulation were normalized within one to three weeks of effective insulin treatment. This rapid reversibility can hardly be explained by the previously demonstrated enlargement in glomerular size and filtration surface area, since these alterations remain unchanged after more than one month of insulin treatment. The metabolic regulation did not influence the size-selective properties of the glomerular wall. Therefore, we suggest that the dominating mechanism involved in the GFR and renal dextran clearance alterations is functional, viz. increased filtration pressure.

Adolescent↗
PubMed1979

Kidney function in acromegaly.

Creatinine clearance and daily urinary albumin and beta2-microglobulin excretion rates (radio-immunoassays) were measured several times in 14 patients with acromegaly. Eleven patients were treated with bromocriptine, 5 to 55 mg/day. The activity of the disease was assessed by measuring urinary growth hormone excretion (radio-immunoassay). In agreement with previous investigations we found the creatinine clearance elevated. However, no correlation was found between this variable and urinary growth hormone excretion. Urinary albumin and beta 2-microglobulin excretion rates were not significantly different from our previous results in 27 adults control subjects. There was no correlation between urinary growth hormone excretion and urinary albumin or beta 2-microglobulin excretion rates. Bromocriptine treatment reduced urinary growth hormone excretion from 220 to 91 ng/24 hours, p less than 0.01, but no significant alterations were induced in the above mentioned kidney function variables.

Acromegaly↗
PubMed1978

Kidney function in normal man during short-term growth hormone infusion.

Kidney function was studied in 9 normal males before and during a 2 h growth hormone (GH) infusion of 50 ng/kg/min. The following variables were measured during each 20 min clearance period: glomerular filtration rate, GFR, effective renal plasma flow, RPF (steady state infusion technique with urinary collections using [125I]iothalamate and [131I]iodohippurate), and urinary albumin and beta2-microglobulin excretion rates (radioimmunoassays). The GH infusion resulted in a 10-fold increase in plasma GH concentration. All the above mentioned variables remained practically unchanged during the infusion except for a small (-5%) but significant decrease in renal plasma flow (P less than 0.01). Our negative results contrast to the findings of increased GFR and RPF during prolonged GH administration and suggest that GH requires several hours or days for its renal effects to become manifest.

Adult↗
PubMed1977

The effect of short-term glucagon infusion on kidney function in normal man.

Kidney function was studied in six normal males before and during a 2 h glucagon (10 ng/kg/min) infusion. The following variables were determined during each 20 min clearance period; glomerular filtration rate (GFR), renal plasma-flow (RPF) , filtration fraction (FF), urinary albumin and beta2-microglobulin-excretion rates. Glucagon infusion resulted in a fourfold increase in plasma glucagon concentration. The infusion induced a significant increase in GFR (+9%), FF (+9%) and urinary beta2-microglobulin excretion rate (+32%), (p less than 0.01). RPF and urinary albumin excretion rates were not significantly changed. We suggest that glucagon may contribute to the reversible kidney function alterations typically found in poorly regulated juvenile diabetes, a state with relative or absolute hyperglucagonaemia.

Adult↗
PubMed1977

Extracellular fluid volume determined by a single injection of inulin in men with untreated essential hypertension.

The extracellular volume (ECV) and plasma volume (PV) were determined simultaneously in nine men with untreated essential hypertension and in nine healthy matched control subjects, using a single injection of inulin and of 131I-labelled human serum albumin, respectively. The average mean arterial blood pressure in the hypertensive group was 178/118 mmHg. ECV was nearly the same in the two groups, viz. 151 ml/kg body weight (SD 17) in the hypertensive group compared to 147 ml/kg (SD 16) in the control group. The corresponding figures for PV were 38.2 ml/kg body weight (SD 4.7) and 43.7 ml/kg (SD 7.9) respectively (P less than 0.1). The calculated interstitial fluid volume (IV) was 113 ml/kg (SD 16) and 103 ml/kg (SD 10) (P less than 0.2). The PV/IV ratio was significantly lower (P less than 0.02) in the hypertensive group (0.34, SD 0.06) than in the normal group (0.42, SD 0.06). The difference might suggest increased transcapillary water filtration in hypertension.

Adult↗
PubMed1977

Increased transcapillary escape rate of albumin and IgG in essential hypertension.

Transcapillary escape rates of albumin and IgG (fractions of intravascular mass of albumin and IgG that pass to the extravascular space per unit time) were determined simultaneously from the initial disappearance of intravenously injected 131I human albumin and 125I human IgG in seven untreated subjects suffering from essential hypertension. The average mean arterial blood pressure of these subjects 193/119 mmHg; four subjects had grade I-III funduscopic changes. Transcapillary escape rates of albumin (TERalb) and IgG (TERIgG) were found significantly increased in the hypertensive subjects, average 7.8 +/- 0.9 (SD) and 4.7 +/- 1.0 (SD) %/h, respectively, compared with normal values of mean 5.2 +/- 1.0 (SD) and 3.0 +/- 0.7 (SD) %/h, respectively (P less than 0.01). There was a statistically significant positive correlation between the mean arterial blood pressure and TER of albumin and of IgG (P less than 0.001). The TERIgG/TERalb ratio was about the same in the hypertensives and the normals. Confirming a previous observation, we found an increase in the daily urinary albumin excretion rate from a normal average of 9.1 (range, 2.4-20.4)mg/24 h to 96 (range, 5.6-565) mg/24 h, P less than 0.05. The present findings can best be explained by increased filtration through normal pores between the endothelial cells in the microvasculature, due to the high arterial blood pressure.

Adult↗
PubMed1977

Increased transcapillary escape rate of albumin in patients with cirrhosis of the liver.

The transcapillary escape rate of albumin (TERalb), i.e. the fraction of intravascular mass of albumin that passes to the extravascular space per unit time, was determined from the disappearance of intravenously injected 125I-labelled human serum albumin during the first 60 min after injection in nine patients with cirrhosis of the liver. Six of the patients had ascites. The wedged hepatic venous pressure or splenic pulp pressure ranged from 20 to 30 mmHg, mean 26 mmHg. Plasma albumin concentration was low, but plasma volume was slightly enlarged, and thus the intravascular mass of albumin was only moderately reduced. The transcapillary escape rate of albumin was significantly elevated in all the cirrhotics, mean 10.2%/h, range 8.8 to 12.3%/h, in comparison to values for twenty-eight normal subjects 5.4%/h, range 3.5-7.2%/h. Our results can best be explained by increased filtration out of the vessels in the portal system, due to the increased portal venous pressure. The increased TERalb probably contributes to the formation of oedema and ascitic fluid.

Adult↗
PubMed1977

Trisomy 8 syndrome. A psychological and somatic study of a mentally non-retarded male with 46,XY/47,XY,+8 chromosome constitution.

A 27-year-old, non-retarded male with trisomy 8 mosaicism (46,XY/47,XY,+8) had a short head, a short broad-bridged nose, a protruding upper lip, pterygium colli, moderate kypho-scoliosis, camptodactyly of all fingers and deep furrowing on the soles. Radiographic examination of columna showed spina bifida of L1 and fusion of L5 and S1. These findings are characteristic for the trisomy 8 syndrome. A psychological study showed a personality characterized by immaturity and lack of spontaneity and self-confidence. An intelligence test (WAIS) placed him within the normal range, but presented an uneven development of the cognitive functions with special difficulties in synthetic abilities and visual scanning. His auditive span was rather low, and his memory functions were somewhat below average.

Abnormalities, Multiple↗