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Biomedical subjects

Q Maggiore

Publications and source records attributed to Q Maggiore.

At least 73 records · Page 4Linked to original sources

Glomerular localization of circulating antiglobulin activity in essential mixed cryoglobulinemia with glomerulonephritis.

Kidney biopsy samples from 27 patients with essential mixed cryoglobulinemia of the IgG-IgM(k) type and glomerulonephritis were studied to assess whether glomerular immunodeposits display antiglobulin (AG) activity similar to that of serum cryo-IgM. A preparation of heat-aggregated human IgG (FAIgG) was used to search for tissue AG activity, and blocking tests and reactivity tests were carried out to define the nature of this activity. Glomerular localization of FAIgG was observed in 17 out of 27 kidney specimens, the positive findings being always associated with IgM deposits. Prior exposure of tissue sections to anti-IgM serum blocked the FAIgG reaction, but no such effect was produced by the pretreatment with other antisera. The positive FAIgG tissue specimens yielded a similar fluorescence pattern with aggregated alkylated-reduced IgG, but did not react at all with the aggregated F(ab')2 or aggregated albumin. The IgM recovered in the eluate of a kidney biopsy specimen displayed AG activity. Patients with AG deposits showed more severe histologic changes and a greater renal functional impairment than did those without. The data support the notion that circulating cryo-IgM anti-IgG participates in the formation of glomerular immunodeposits and in the genesis of renal damage.

Adult↗

Defective reflex control of heart rate in dialysis patients: evidence for an afferent autonomic lesion.

1. To localize the site of autonomic abnormality in patients undergoing haemodialysis, tests of overall autonomic function based on either changes in blood pressure (posture, sustained handgrip) or heart rate (Valsalva manoeuvre, 30 : 15 ratio, deep breathing test) were used. Integrity of the sympathetic efferent arc was examined by using the cold pressor test and the parasympathetic efferent arc by the atropine test. Eighteen patients and 12 control subjects were studied. 2. Changes in blood pressure in standing, sustained handgrip and in the cold pressor test were the same in the two groups. 3. In contrast, 11 patients had abnormal results in at least two of the three heart-rate-based tests. 4. Three of the 11 dialysis patients with evidence of autonomic involvement showed abnormal responses to atropine, indicating an efferent parasympathetic lesion, whereas the majority had a normal response to the atropine test, suggesting an afferent lesion only. 5. Evidence of autonomic involvement was not associated with hypertension nor confined to patients with dialysis hypotension.

Adult↗

Effect of furosemide on renal size: ultrasonic characterization of renovascular hypertension.

In this pilot study, sequential ultrasonic scanning was used to assess (a) whether furosemide injection normally causes an enlargement of kidney size, and (b) whether this effect is blunted in renovascular hypertensives to such a degree as to bear potential diagnostic value. Furosemide caused similar degrees of maximal area enlargement in both kidneys of 10 healthy subjects (16.1 +/- 3.9%) and 10 essential hypertensives (14.8 +/- 4.2%) whereas in 11 renovascular patients maximal distension of the affected kidneys was significantly blunted (9.4 +/- 3.7%) in comparison with that of contralateral kidneys (19.6 +/- 7.7%). In the 6 hypertensives with one small kidney not due to renal artery stenosis, maximal enlargement of the affected kidneys averaged 22.8 +/- 5.1%, and that of contralateral kidneys 15.8 +/- 4.2%. In 8 out of the 11 patients with renovascular hypertension the difference in response between the paired kidneys had values outside the ranges of patients with both the other forms of arterial hypertension. The data suggest that the furosemide test may be of value in the screening for renovascular hypertension.

Adult↗

Effect of chronic propranolol treatment on bone changes of secondary hyperparathyroidism in dialysis patients.

To assess the effect of long-term propranolol therapy on uremic osteodystrophy, we evaluated retrospectively the biochemical, X-ray, and bone histological changes in 9 dialysed hypertensives who had been on propranolol treatment for periods ranging from 1 to 8 years. The control group included 9 well-matched dialysed uremics never treated with beta-blockers. The two groups did not differ in serum ionized calcium or iPTH levels. The incidence of bone resorption evaluated on X-ray findings and on bone biopsy specimens was of a comparable degree in the two groups. Our data show that propranolol even if started early in the course of renal failure, is of no benefit in preventing uremic bone disease.

Bone Resorption↗

Light-chain nephropathy in patient with renal carcinoma.

Paraneoplastic syndromes are often associated with renal parenchymal tumours. This report describes a case of renal-cell carcinoma with kappa-chain nephropathy. The patient, a 60-year-old man, had renal tubular dysfunction, shown by low serum concentrations of urate and phosphate. Kappa-chains were found in both serum and urine, but no lambda-chains were found. Investigations showed a clear-cell carcinoma, and the patient underwent a radical nephrectomy. Two years after operation serum phosphate and urate concentrations had returned to normal, and kappa-chains were undetectable in serum or urine. The absence of lambda-chains indicates that the light-chain proteinuria was due to overproduction of the M component, and the disappearance of kappa-chains after the operation suggests a causal relation between the renal tumour and the overproduction of the M component.

Adenocarcinoma↗

HBsAg glomerular deposits in glomerulonephritis: fact or artifact?

To evaluate the role of the hepatitis B virus infection in the pathogenesis of glomerulonephritis, we screened 136 consecutive patients with various types of glomerular lesions for the presence of HBsAg either in serum or in kidney biopsy specimens by means of radioimmunoassay and direct immunofluorescence technique, respectively. In selected patients, we carried out the search for antiglobulin activity (AA) factor(s) within the renal tissue with a fluoresceinated aggregated human IgG preparation (FITC-IgGagg). Eleven HbsAg seropositive patients were found, none of whom showed HBsAg deposits within their kidney biopsy specimen. Five of the remaining 125 seronegative patients, 3 with mixed cryoglobulinemia and 2 with lupus nephritis, showed glomerular-positive staining with a rabbit fluoresceinated anti-HBs serum and deposits of IgM endowed with AA, along with IgG and complement factors. The presence of HBsAg within the glomeruli was not confirmed, however, when a fluoresceinated anti-HBs Fab' preparation was used instead of the fluoresceinated anti-HBs serum. The pretreatment of the tissue sections with unconjugated anti-IgM serum blocked the direct staining for HBsAg and FITC-IgGagg, but not that of the other immunoreactants. Conclusion. The IgM AA deposits may interfere with the direct immunofluorescence testing for HBsAg, leading to erroneous interpretation.

Antigen-Antibody Complex↗

Bone changes in end-stage oxalosis.

Primary hyperoxaluria is a rare metabolic disease characterized by exaggerated production of oxalic acid. Clinically the disease is characterized by recurrent calcium nephrolithiasis, progressive renal failure, and early death in uremia. As the regular dialysis treatment may prolong survival, a new syndrome may develop. This is due to intense and continuous deposition of calcium oxalate crystals in soft and bone tissues. The radiologic aspects of oxalate deposition in four adult patients on chronic renal dialysis with histologic and clinical evidence of massive bone oxalosis are reported.

Adolescent↗

Cardiothoracic ratio as a guide to ultrafiltration therapy in dialyzed patients.

This study evaluated the cardiothoracic ratio (CTR) and the roentgenologic heart volume (RHV) as indexes of body fluid retention in 37 uremics on maintenance dialysis therapy. Both indexes related to a highly significant degree with the variations of body fluids balance assessed by the changes in body weights. Cardiomegaly (CTR greater than .500) subsided with adequate ultrafiltration therapy in most patients including those having blood pressure values within the normal range. It is concluded that the measurements of CTR provides an useful guide to ultrafiltration therapy especially in those patients whose blood pressure fails to sense the body fluid retention.

Adult↗

[Oxolinic acid treatment of urinary sepsis in patients with renal insufficiency].

The effect of oxolinic acid, administered at the rate of 750 mg twice/day, has been studied on 31 patients with urinary tract infections. Many of them had a marked impairment of renal function due to nephropathies of various origin. Favourable results, with sterile urine and complete remission of symptoms, were obtained in 73.3%. Patients who were resistant to previous different therapies, were successfully treated. Oxolinic acid was on the whole well tolerated and proved to be effective also in patients with impaired renal function. In some of the latter an improvement in renal function occurred as a result of the effective urinary infection care. The tolerability of oxolinic acid was good: only one patient interrupted the treatment because of insomnia; other 4 had transient and mild side-effects.

Adult↗

Chronic hemodynamic effects of propranolol treatment in dialysis-refractory hypertension.

The hemodynamic mechanism of the hypotensive effect of propranolol was studied by quantitative radiocardiography in 8 patients with dialysis-resistant hypertension. Propranolol treatment brought about a decrease in mean arterial pressure and peripheral vascular resistances. The cardiac index was slightly reduced only in the early stage of the treatment. No significant difference was found between patients on treatments lasting longer than 3 months and patients with dialysis-controlled hypertension. The results show that propranolol can be used safely as the sole antihypertensive agent in patients with dialysis-resistant hypertension.

Adult↗

HBsAg immune complex glomerulonephritis.

Out of 97 patients with various forms of glomerulonephritis 10 were found to be HBsAg seropositive. None of these showed HBsAg immunodeposits within the kidney. Direct immunofluorescent kidney staining for HBsAg was observed in 4 out of 87 HBsAg seronegative patients. The HBsAg staining in kidneys was a false positive reaction due to binding of the Fc portion of the fluoresceinated IgG molecules to the IgM RF tissue deposits. The false positive reaction for HBsAg is not revealed by the usual specificity controls for fluorescence staining. The role of HBsAg in glomerulonephritis remains unproven.

Antigen-Antibody Complex↗

Selective removal of plasma cryoglobulins in cryoglobulinaemia.

Cryoglobulins were removed from the plasma of two patients with mixed cryoglobulinaemia (IgM(k)-IgG type) associated with severe membrano-proliferative glomerulonephritis and angiitis. The removal of about half the circulating cryo-Igs ('cryo-Igpheresis') was followed by a brisk rebound in cryo-Igs due to the rapid synthesis rate of monoclonal IgM(k) with anti-IgG activity. 'Cryo-Igpheresis' + cyclophosphamide treatment suppressed the rebound of cryo-IgGs, but not that of the cryo-IgMs. This differential effect was due to decrease of the antibody activity of cryo-IgMs. The clinical implications of such changes need further evaluation.

Cryoglobulins↗

Long-term propranolol treatment of resistant arterial hypertension in haemodialysed patients.

1. Propranolol was given to eight haemodialysed patients with resistant arterial hypertension for periods ranging from 6 to 16 months. 2. The treatment brought about an excellent control of blood pressure in all cases. 3. After withdrawal of propranolol plasma renin activity rose on average 40% compared with the value obtained during treatment. However, no significant relationship was found between the change in plasma renin activity and the change in the diastolic blood pressure. 4. Stopping propranolol resulted in a prompt rebound of arterial pressure toward pretreatment values. However, hypertension was always controlled on resuming drug treatment. 5. The results show that this form of hypertension can be controlled on a long-term basis with propranolol. However, the effect on blood pressure seems not to be mediated by suppression of renin secretion.

Adult↗