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Biomedical subjects

S J Guggenheim

Publications and source records attributed to S J Guggenheim.

At least 19 recordsLinked to original sources

Morphologic correlates of glomerular oxidant injury induced by the myeloperoxidase-hydrogen peroxide-halide system of the neutrophil.

Neutrophilic polymorphonuclear leukocytes can mediate glomerulonephritis by releasing reactive oxygen species such as H2O2. We have previously demonstrated that H2O2-mediated glomerular injury can be potentiated by reaction with polymorphonuclear leukocyte myeloperoxidase (MPO). When MPO was perfused into renal arteries of rats, it bound to the glomerular capillary wall due to its cationic charge. Subsequent perfusion with nontoxic concentrations of H2O2 and halides resulted in acute glomerular injury, halogenation of the glomerular basement membrane, and proteinuria. The studies reported here document the morphologic changes that accompany MPO-mediated glomerular injury. Acutely, there is severe injury to the endothelium with cell swelling and lysis. Within 10 minutes, a marked platelet influx occurs. Platelets frequently occlude capillary lumens and bind to areas of denuded glomerular basement membrane where platelet degranulation results. By 4 days, the platelet infiltration has ceased, and a reparative phase develops characterized by marked proliferation of resident endothelial cells and possibly mesangial cells. By 21 days postperfusion, the glomerular lesion had largely resolved. In contrast, control rats perfused with MPO alone, H2O2 alone, or buffered saline alone demonstrate minimal glomerular injury at all times studied. MPO-mediated glomerular disease results in endothelial and mesangial cell injury, activation of platelets, and a subsequent proliferative response. These morphologic changes resemble those seen in several forms of inflammatory and proliferative glomerulonephritis in man.

Animals↗

Effect of pertussis toxin on water metabolism in the rat.

Pertussis toxin administered to rats resulted in a polyuric state that was due to enhanced renal water excretion. Pertussis toxin also induced a defect in renal water conservation. These abnormalities in renal water excretion could not be attributed to polydipsia, impaired synthesis and/or release of arginine vasopressin or renal tubular dysfunction with solute diuresis. No evidence of pertussis toxin-induced renal tubular damage was present. These results indicate that pertussis toxin induces nephrogenic diabetes insipidus and this defect occurs at the level of the renal collecting tubule.

Animals↗

Prednisone therapy of membranoproliferative glomerulonephritis in children.

Six children with biopsy-proved type 1 membranoproliferative glomerulonephritis (MPGN) improved clinically during a 2-year course of prednisone therapy. All children had nephrotic syndrome. Creatinine clearance was less than or equal to 80 ml/min/1.73 m2 in four patients. Initial prednisone dosage ranged from 20 mg every other day to 2 mg/kg/day (maximum 60 mg), with subsequent modifications based on improvement. After completion of a 2-year course of steroid therapy, a repeat kidney biopsy was performed in each child; a decrease in glomerular disease activity was noted in five of them. After a mean follow-up of almost 5 years, all children have creatinine clearance greater than 120 ml/min/1.73 m2, and only one remains nephrotic. Although the use of prednisone in children with MPGN remains controversial, we have observed a diminution in proteinuria and normalization of creatinine clearance with therapy initiated early in the disease course.

Adolescent↗

Systemic lupus erythematosus without clinical renal abnormalities: renal biopsy findings and clinical course.

The extent and significance of renal biopsy abnormalities in patients with systemic lupus erythematosus (SLE) without clinical renal abnormalities is controversial. We report 11 consecutive SLE patients who were biopsied without clinical renal abnormalities. All 11 patients had mesangial changes either by light microscopy or by immunofluorescent staining, and none had changes of focal or diffuse proliferative glomerulonephritis. Additionally none had deterioration of renal function during the mean follow-up period of 6.3 years.

Adolescent↗

Tubulointerstitial renal disease in systemic lupus erythematosus.

Tubulointerstitial renal disease is found frequently in patients with systemic lupus erythematosus. Despite the frequency of this entity, little is known about the prognostic significance of this biopsy finding. We reviewed 46 consecutive renal biopsy specimens from patients with systemic lupus erythematosus who were followed up for a mean of 5.4 years. Tubulointerstitial abnormalities were present in 39% of the entire group of patients and in 51% of the patients who had clinical evidence of renal abnormalities. Tubulointerstitial inflammation was closely associated with diffuse proliferative glomerulonephritis, with elevation of serum creatinine (SCr) concentration at biopsy, and with increased frequency of proteinuria both at biopsy and at follow-up. Additionally, active interstitial inflammation was associated with an increased risk of doubling the entry SCr concentration. The presence or absence of tubulointerstitial disease, however, did not add additional prognostic information to the predictive power of the entry SCr concentration or the glomerular histologic features.

Adult↗

The renal concentrating defect after gentamicin administration in the rat.

The present studies were carried out to delineate the mechanism of the polyuric state and renal concentration defect seen after gentamicin. Gentamicin was given at a dosage of 100 mg/kg/day subcutaneously for either 4 or 5 days to Sprague-Dawley rats and resulted in a reversible, polyuric form of acute renal failure. This nonoliguric acute renal failure was accompanied by significant polydipsia and a renal concentrating defect 11 days after gentamicin. To assess the role of polydipsia in the polyuria and renal concentrating abnormality, water intake was restricted in gentamicin-treated animals to match intake of control animals. Elimination of the polydipsia failed to eliminate the polyuria and to improve the renal concentrating abnormality. Postdehydration plasma vasopressin levels were higher in gentamicin-treated than control animals, suggesting that the renal concentrating defect was nephrogenic in origin. Daily urinary prostaglandin E2 excretion was comparable in gentamicin-treated and control animals. However, indomethacin failed to improve urinary concentrating ability, suggesting that the renal concentrating defect was prostaglandin E2 independent. Finally, depressed postdehydration inner medullary tonicity was found in gentamicin-treated animals In summary, gentamicin administration in the rat was associated with a reversible polyuric form of acute renal failure and a renal concentrating defect. This concentration defect was nephrogenic in origin, independent of polydipsia and prostaglandin E2, and was associated with a decrease in inner medullary tonicity.

Acute Kidney Injury↗

Glomerular dynamics and morphologic changes in the generalized Shwartzman reaction in postpartum rats.

The roles of glomerular functional and morphologic changes were examined in the acute renal failure associated with generalized Shwartzman reaction in postpartum Munich Wistar rats. The susceptibility of postpartum rats to acute deterioration in renal function after a 2-h endotoxin infusion was found to be greater than in virgin litter mates: glomerular filtration rate fell by 93% in the former vs. 24% in the latter group (P less than 0.001). In postpartum rats there were marked changes in platelet count and fibrinogen level (P less than 0.025) compatible with consumption coagulopathy. Renal blood flow and glomerular filtration rate fell from 5.5 +/- 0.9 and 0.74 +/- 0.12 to 2.0 +/- 0.7 and 0.12 +/- 0.01 ml/min, respectively (both P less than 0.001). Blood pressure did not change. Results of glomerular dynamics studies showed decreases in single nephron filtration rate from 28 +/- 7 to 6 +/- 4 nl/min and in glomerular plasma flow rate from 77 +/- 26 to 23 +/- 12 nl/min (both P less than 0.001). Afferent net ultrafiltration pressure fell from 20 +/- 3 to 5 +/- 4 mm Hg due to a fall in glomerular capillary hydraulic pressure from 47 +/- 1 to 29 +/- 5 mm Hg (P less than 0.001). There were four- and twofold increases in afferent and efferent arteriolar resistances, respectively. Less than 20% of glomeruli had evidence of fibrin deposition after 2 h of endotoxin infusion, a time when glomerular filtration rate was reduced by greater than 90%. [1-Sar, 5-Ile, 8-Gly] angiotensin II infusion before endotoxin significantly protected glomerular filtration rate, 62 vs. 7% of control in rats with no preinfusion (P less than 0.01) despite consumption coagulopathy and glomerular fibrin deposition similar to rats without pretreatment. These data suggest that the early deterioration in renal function in the generalized Shwartzman reaction in the postpartum rat is due to major changes in glomerular dynamics induced by neurohumoral agents and that glomerular fibrin deposition plays a lesser pathogenetic role at this time in this disorder. The study does not address the pathogenesis of renal failure in pregnancy nor peripartum renal failure in another species.

Animals↗

Diffuse proliferative lupus glomerulonephritis. Recovery from prolonged renal failure.

A patient with systemic lupus of erythematosus, diffuse proliferative lupus glomerulonephritis, and deteriorating renal function was treated with immunosuppression. During the subsequent eight weeks of hemodialysis and immunosuppression, substantial recovery of renal function occurred, allowing for cessation of dialysis. In the following year, the endogenous creatinine clearance increased to 30 mL/min. A therapeutic trial of prednisone is indicated for patients with abrupt, severe deterioration in renal function in association with clinical, histological, or serological evidence of activity of lupus nephritis in the absence of other causes of renal failure.

Adult↗

Role of antidiuretic hormone in impaired urinary dilution associated with chronic bile-duct ligation.

1. The effect of chronic bile-duct ligation on systemic and renal haemodynamics and on the capacity to dilute the urine was studied in conscious rats. Sham-operated rats served as controls. 2. In the rats with bile-duct ligation, the maximal urinary diluting capacity was impaired, despite an expanded plasma volume, a normal mean arterial pressure and cardiac output, and normal intrarenal determinants of water excretion including distal delivery of fluid and function of the diluting segment. 3. In contrast, maximal urinary dilution capacity was intact in rats with congenital central diabetes insipidus and chronic bile-duct ligation. 4. It is concluded that the defect in urinary dilution in rats with chronic bile-duct ligation is dependent on antidiuretic hormone.

Animals↗

Simultaneous immunologic studies of skin and kidney in systemic lupus erythematosus clinicopathologic correlations.

Thirty-two biopsies of kidneys and of normal skin were performed simultaneously on patients with systemic lupus erythematosus (SLE) to determine whether the deposition of immune reactants in skin was correlated with the severity of renal injury or with several serologic measures of systemic disease activity. Immunofluorescent deposits at the dermal-epidermal junction (lupus band test) did not correlate with any clinical or histologic measures of glomerulonephritis or with serologic abnormalities. Immune deposits in dermal venules were found in 56% of the skin biopsies and were correlated with hypocomplementemia and higher levels of immune complexes in serum, and possibly with glomerular subendothelial electron dense deposits. Azathioprine therapy was correlated with absence of both sub-epidermal and vascular immune deposits. Immuno-fluorescent findings on serial skin biopsies on 13 patients were highly inconsistent. It is concluded that the lupus band test is clinically useful only as a diagnostic aid but not helpful in assessing renal or serologic activity of lupus, and that dermal vascular deposits of immunoglobulin or complement are more frequent than previoulsy recognized and correlate with measures of circulating immune complexes.

Adolescent↗

The kidney in progressive systemic sclerosis: a prospective study.

Nine normotensive progressive systemic sclerosis patients with normal renal function underwent renal biopsy. Four specimens had prominent vascular abnormalities, two mild vascular abnormalities, and three were normal. Vascular deposits of C3 were present in all specimens. Plasma renin activity was elevated in three of four patients with prominent vascular abnormalities, one of two patients with mild vascular lesions, and none of two patients with normal biopsies. Plasma renin activity elevation in response to cold pressor testing in the four patients with prominent vascular lesions was 5.6 ng/ml.h compared to 0.55 ng/ml.h in those with mild or no lesions and 0.26 ng/ml.h in six control subjects. These data indicate that renal vascular lesions may be present in normotensive patients. Elevation or a substantial rise in plasma renin activity (1.8 ng/ml.h or greater) in response to cold pressor testing suggests preclinical renal involvement.

Adult↗

A micropuncture study of the early phase of acute urate nephropathy.

The early pathophysiological changes in acute urate nephropathy were investigated in a rat model using micropuncture, clearance, and morphologic methods. Plasma urate was increased from 1.2 +/- 0.6 to 20.1 +/- 3.1 mg/100 ml (P less than 0.001). Urinary urate rose from 24.3 +/- 5.1 to 142.2 +/- 21.0 mg/100 ml (P less than 0.001). Renal plasma flow and glomerular filtration rate fell to 17 and 14% of control values, respectively, and urine flow rate decreased from 11.3 +/- 4.8 to 4.2 +/- 2.2 mul/min (all P less than 0.005) Superficial nephron filtration rate fell less than that of the whole kidney (70 vs. 86%). Both proximal and distal tubular pressures were increased from 10.6 to 26.1 mm Hg and from 7.2 to 24.7 mm Hg, respectively (P less than 0.005). Efferent arteriolar and peritubular capillary pressures were increased twofold. Vascular resistance beyond the peritubular capillaries increased from 4.8 X 10(9) to 21.6 X 10(9) dynes s/cm5. Extensive deposits of uric acid and urate were found in the tubular system and vasa recti from the corticomedullary junction to the tip of the papilla. It is concluded from these experiments that not only tubular obstruction in the collecting ducts, but also obstruction of the distal renal vasculature, are the primary early pathogenetic events in acute urate nephropathy.

Absorption↗

Serious pulmonary hemorrhage, glomerulonephritis, and massive steroid therapy.

A patient suffered from acute glomerulonephritis with modest renal impairment and life-threatening pulmonary hemorrhage. The pulmonary hemorrhage caused severe hypoxia that necessitated artificial ventilation. As a last resort, 1 g/day of methylprednisolone was administered intravenously. Rapid cessation of pulmonary hemorrhage ensued with clearing of the lungs fields. We suggest that large doses of glucocorticosteroids should be administered to patients with life-threatening pulmonary hemorrhage before considering bilateral nephrectomy, especially if the renal function is still adequate. Bilateral nephrectomy is an irreversible approach and, as with massive doses of steroids, has yet to be proved to be a consistently effective mode of therapy.

Acute Disease↗

Failure of angiotensin II inhibitor to modify hyperacute rejection.

The effect of angiotensin II inhibitor (sar1,gly8 angiotensin II) upon the pig-to-dog (10 pigs to 20 dogs) modified renal xenograft model has been studied. The angiotensin II inhibitor does not prevent hyperacute rejection (HAR). This implies that the vasocaonstriction which occurs during the HAR is not related to high levels of angiotensin II.

Angiotensin II↗