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Biomedical subjects

G Bianchi

Publications and source records attributed to G Bianchi.

At least 397 records · Page 22Linked to original sources
PubMed1986

Comparison of various genetic hypertensive rat strains.

Comparative studies on nine genetic hypertensive rat strains [two stroke-prone spontaneously hypertensive rats (SHRSP) and Dahl salt-sensitive (DS) strains, and one strain each of spontaneously hypertensive rats (SHR), Lyon hypertensive rats (LH), Milan hypertensive strain (MHS), genetically hypertensive rats (GH) and Sabra hypertensive rats (SBH)] and their respective controls [two Dahl salt-resistent (DR) strains and one strain each of Wistar-Kyoto rats (WKY), Lyon normotensive rats (LN); Lyon low blood pressure rats (LL), Milan normotensive strain (MNS), genetically normotensive rats (GN) and Sabra normotensive rats (SBN) and their original strain, Sabra rats (SB)], in groups consisting of 6-10 males from each strain, were carried out at 10-12 weeks of age under the same experimental conditions. After checking the developmental course of blood pressure and changes in body weight, they were killed at 12 weeks of age for blood analysis and organ-weight examinations. The SHRSP and SHR showed markedly higher blood pressure levels and earlier blood pressure rises in comparison with other hypertensive strains, although they had higher blood pressure than their respective controls. Among various organ weights examined, all hypertensive strains commonly showed increases in left ventricular weight in proportion to blood pressure rises. Kidney weights were significantly decreased only in MHS compared with MNS, while they were either unchanged or significantly greater in other hypertensive strains. Weights of adrenal glands were greater in the two strains of DS and in LH than in their respective control strains. These comparative data indicate possible differences in the pathogenic mechanism involved in these genetic hypertensive rat strains.

Animals↗
PubMed1986

Cell membrane abnormalities and genetic hypertension.

Evidence indicates that an alteration in kidney function has a causal role in the pathogenesis of hypertension in the Milan hypertensive strain (MHS) rat. At the prehypertensive stage, these animals have increased glomerular filtration rate and 24-hour urinary output, whereas plasma renin activity and urinary kallikrein are lower. After transplantation, the MHS kidney increases the blood pressure of a normotensive recipient. Micropuncture experiments, where single nephron filtration rate, tubuloglomerular feedback, proximal tubular reabsorption, micro-pressures in tubuli, and interstitium and interstitial oncotic pressure were measured, suggest that the intrinsic ability of MHS proximal tubular epithelium to reabsorb solute and water is greater in prehypertensive MHS rats than in Milan normotensive strain (MNS) rats. Also rheogenic Na transport across the brush-border vesicles isolated from proximal tubular cells is faster. When erythrocytes and proximal tubular cells of MHS rats are compared to those of MNS rats, the former have smaller volume and Na content, whereas the Na transport is faster and the Ca ATPase at Vmax is lower. This indicates that the genetic cellular abnormality responsible for the renal functional abnormality and hypertension is also present in erythrocytes. Moreover, MHS erythrocyte abnormalities are genetically determined within the stem cells and are genetically associated with hypertension. Because a correlation was also found in human hypertension between erythrocyte Na transport abnormality and renal function, it is proposed that the erythrocyte may be used for studying the genetic molecular mechanisms of hypertension.

Animals↗
PubMed1986

Effects of captopril and of other antihypertensive drugs on cell membrane ion transport--a preliminary report.

We measured red blood cell Na+-K+ pump, Na+-Li+ countertransport and Na+-K+ cotransport activities, together with intraerythrocyte sodium content before and after 3 months therapy with captopril and two other antihypertensive drugs (atenolol and canrenoate potassium) in subjects suffering from essential hypertension. All patients discontinued any previous treatment at least 3 months before the basal evaluation of cell membrane activities. All three drugs significantly lowered blood pressure but only captopril and canrenoate potassium induced significant modifications in red blood cell parameters. After three months of captopril therapy intraerythrocyte Na+ content was significantly decreased (P less than 0.01) without any detectable change in cation transport system activity. After 3 months of canrenoate potassium therapy we also observed a significant decrease in internal Na content (P less than 0.01), together with a significant increase in Na+-K+ pump (P less than 0.02) and Na+-Li+ countertransport (P less than 0.05) activities.

Adolescent↗
PubMed1986

A renal abnormality in the Milan hypertensive strain of rats and in humans predisposed to essential hypertension.

Many similarities in kidney-function abnormalities were found between hypertensive rats of the Milan strain (MHS) and young normotensive human subjects with hypertensive parents, compared with the appropriate controls. These similarities included an increased glomerular filtration rate, increased pressor effect of the kidney after transplantation, increased 24-h urinary output and lower plasma renin activity and urinary kallikrein. The isolated MHS kidney perfused in vitro with an artificial medium had a higher glomerular filtration rate, a higher urinary output, higher tubular sodium reabsorption and higher oxygen consumption than the kidney of control Milan normotensive rats (MNS). Further, reogenic sodium transport across brush border vesicles isolated from proximal tubular cells is faster in MHS than in MNS. Erythrocytes and proximal tubular cells of MHS have a lower volume and sodium content than those of MNS, while sodium transport is faster and the Ca2+-ATPase at Vmax is lower. This indicates that the 'genetic' cellular abnormality responsible for the renal-function abnormality and the hypertension is also present in erythrocytes. Thus these cells may be used to study the genetic cellular mechanisms of hypertension. Experiments with bone marrow transplantation and with F2 hybrids obtained by crossing the F1 (MHS X MNS) hybrids showed that the MHS erythrocyte abnormalities are genetically determined within the stem cells and are genetically associated with the hypertension. Since, in human hypertensives, there was a correlation between abnormal erythrocyte sodium transport and renal function, it is proposed that erythrocytes may be used in studying the cellular molecular mechanisms of hypertension.

Animals↗
PubMed1986

Age-dependent glomerulosclerosis and proteinuria occurring in rats of the Milan normotensive strain and not in rats of the Milan hypertensive strain.

The development of an age-dependent glomerulosclerosis and proteinuria was investigated in two strains of rats in a model of moderate hypertension comparing rats of the Milan Hypertensive Strain (MHS) with rats of the Milan Normotensive Strain (MNS). Serum creatinine, urinary protein excretion, renal morphology (light- and electronmicroscopy) and morphometry of the media thickness of the intrarenal arteries and of the thickness of the glomerular basement membrane were studied in 2- to 16-month-old MHS and MNS rats. Serum creatinine did not differ between MNS and MHS rats in any age group. MNS rats developed a significant proteinuria which coincided with a glomerulosclerosis in about 22% of the glomeruli at 13 to 16 months. In contrast, urinary protein excretion in MHS rats remained stable during the entire observation period; glomerulosclerosis occurred only in 3% of the glomeruli at 13 to 16 months. As a consequence of hypertension media thickness of intrarenal arteries of MHS rats significantly exceeded that of MNS rats, in the interlobular arteries already at 2 months and in the arcuate arteries at 13 to 16 months. In contrast, thickness of the glomerular basement membrane of MHS rats never exceeded that of MNS rats. From these data we conclude, that glomeruli of MHS rats may be protected against the development of an age-dependent glomerulosclerosis and proteinuria. Further support for this conclusion may also be derived from recent experiments showing that the tubuloglomerular feedback sensitivity is significantly higher in MHS than in MNS rats (41).

Aging↗
PubMed1985

Considerations regarding a case of leiomyoma of the urinary bladder.

In spite of its rarity, leiomyoma of the bladder deserves to be better known as its diagnosis is not always obvious, depending as it does mainly on urography confirmed by anatomo-pathological examination, and particularly because its treatment is simple and the prognosis always favourable, a fact worthy of note in dealing with a tumour of the bladder.

Adult↗
PubMed1985

Diagnostic value of urinary cyclic AMP measurement in patients with calcium nephrolithiasis.

One hundred patients with recurrent calcium nephrolithiasis were submitted to the Pak test. At fasting state hypercalciuria was found in 27 cases, while a group of 16 further patients became hypercalciuric after oral calcium load. Only measurement of urinary cAMP excretion in both conditions made it possible to diagnose renal hypercalciuria in 9 out of 27 patients in the former group; according to test results 4 patients were expected to have primary hyperparathyroidism, but afterwards the disease was identified in only one case.

Administration, Oral↗
PubMed1985

Dichloromethylene-diphosphonate in patients with prostatic carcinoma metastatic to the skeleton.

A total of 17 patients with multiple osteoblastic bone metastases owing to prostatic carcinoma was treated with 2-dichloromethylene-diphosphonate, a powerful inhibitor of bone resorption. The drug was given intravenously (300 mg.) for 2 weeks and then orally (3,200 mg.) or intramuscularly (100 mg.) for 4 to 11 weeks. A definite improvement in pain, assessed by daily consumption of analgesic drugs and by an analogic scale, was observed within 10 days in 16 of the 17 patients. Four patients confined to bed rest for pain were able to walk after 2 weeks and reversal of paralysis also was noted in 1 patient. Transient changes in serum calcium (decreasing) and alkaline phosphatase (increasing) were observed in most patients. In the 3 patients in whom it was performed, repeated bone scanning showed a partial regression of pathological areas in 2 and the complete disappearance of most pathological areas in 1. Our results suggest that 2-dichloromethylene-diphosphonate may represent an important supportive treatment in patients with bone metastases owing to prostatic carcinoma, providing sustained relief of pain and regression of bone destruction without undesirable side effects.

Adult↗
PubMed1985

Calcium ATPase in erythrocytes of spontaneously hypertensive rats of the Milan strain.

Calcium (Ca)-dependent ATPase activity was determined in erythrocyte membrane ghosts from normal and spontaneously hypertensive rats of the Milan strain in order to detect changes in enzyme activity which had previously been shown in the spontaneously hypertensive rat strain. Activity was similar in control and hypertensive rats in the absence of calmodulin. In contrast, activity in the presence of saturating amounts of calmodulin was significantly lower in the hypertensive rats. At the Vmax (free Ca2+ concentration 10 mumol/l) the decrease was about 30% (70.1 +/- 8.94 versus 49.1 +/- 4.75 nmol of ATP split/mg of ghost proteins per min; P less than 0.05). The affinity of the ATP-dependent Ca2+ pump for Ca2+ (Km about 1 mumol/l) was not altered in the hypertensive rats. It is possible that deficient Ca ATPase activity sustains an increase of intracellular free Ca in cells of hypertensive rats concomitant with the intracellular sodium (Na) decrease typical of this strain.

Animals↗