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Biomedical subjects

C G Biava

Publications and source records attributed to C G Biava.

30 records · Page 2Linked to original sources

Membranous lupus nephropathy initially seen as idiopathic membranous nephropathy. Possible diagnostic value of tubular reticular structures.

When a renal lesion is the sole manifestation of systemic lupus erythematosus (SLE), differentiation from other nephropathies is difficult. The membranous form of lupus nephritis is especially difficult to distinguish from idiopathic membranous nephropathy, particularly when multisystem and serologic features of SLE are absent. We report two cases in which the initial renal biopsy findings suggested idiopathic membranous nephropathy and in which the subsequent emergence of SLE might have been predicted by the presence of tubular reticular structures. We identified these structures in 177 of 183 (96.7%) renal biopsy specimens from patients with SLE, but in only three of 128 (2.3%) renal specimens from patients with membranous nephropathy. Tubular reticular structures are markers of the renal lesion of SLE and may be helpful in differentiation from membranous nephropathy.

Adult↗

Red blood cell casts in acute interstitial nephritis.

A 45-year-old woman receiving hydralazine and hydrochlorothiazide therapy was found to have a reduced glomerular filtration rate, a positive antinuclear antibody reaction, and RBC casts in the urinary sediment. Glomeruli with normal morphology (light, immunofluorescence, electron microscopy) were found on renal biopsy; however, a mild interstitial nephritis was observed that predominantly involved the distal tubules. The etiology of this inflammatory process is unknown. Changes in distal tubular function correlated with the morphology: acidification was impaired whereas concentrating ability was normal. Although RBC casts have been thought to be diagnostic of glomerular diseases, the present case demonstrates that tubulointerstitial disease can be responsible for RBC cast formation.

Acute Disease↗

Comparative toxicities of enflurane, fluroxene and nitrous oxide at subanaesthetic concentrations in laboratory animals.

We compared the toxicities of subanesthetic concentrations of fluroxene, enflurane and nitrous oxide in mice, rats and guinea pigs which were in an active growth phase. Fluroxene produced a greater mortality and decrement in weight gain than enflurane and nitrous oxide despite administration of far lower concentrations. Enflurane, 0.1 MAC, resulted in a detrimental effect on weight and early mortality in mice but not in rats or guinea pigs. Nitrous oxide, 0.1 MAC, resulted in only a minor effect on weight gain in guinea pigs and an increased incidence of focal inflammatory liver changes in mice. No consistent injury to any organs other than liver or kidney were found.

Animals↗

The effects of glucose and cyclic GMP on RNA synthesis and nuclear morphology in starved rats.

Feeding rats in diet high in glucose has been demonstrated to inhibit the induction of many enzymes, block the action of glucocorticoids, and, in general, appears to result in decreased cyclic AMP activity. We found that glucose feeding depresses both messenger RNA (mRNA) and non-mRNA synthesis. Electron microscopic examination of the nucleus revealed that glucose feeding decreases the granular component of liver cell nucleoli. It only slightly decreases liver cyclic AMP levels, but produces a sixfold elevation in levels of the cyclic AMP antagonist, cyclic GMP. Administration of bromocyclic GMP, like glucose feeding, depresses mRNA synthesis, but does not simulate the effect of the carbohydrate on nuclear morphology. In addition, glucose feeding halves liver inorganic phosphate and triples ATP levels. Phosphorylation of nuclear proteins, however, remains unaltered. Despite the antagonism between glucose feeding and glucocorticoid activity, the former compound did not change the binding of dexamethasone to liver nuclei.

Adenosine Triphosphate↗

Bladder tumors in rats fed cyclohexylamine or high doses of a mixture of cyclamate and saccharin.

Papillary transitional cell tumors were found in the urinary bladders in 8 rats out of 80 that received 2600 milligrams per kilogram of body weight per day of a mixture of sodium cyclamate and sodium saccharin (10:1) for up to 105 weeks. From week 79 on, several of these rats received cyclohexylamine hydrochloride (125 milligrams per kilogram per day, the molecular equivalent of the conversion of about 10 percent of the cyclamate dosage to cyclohexylamine) in addition to the sodium cyclamate and sodium saccharin. In another study in which 50 rats were fed daily 15 milligrams of cyclohexylamine sulfate per kilogram of body weight for 2 years, eight males and nine females survived. One of the eight males had a tumor of the urinary bladder. In neither study were bladder tumors found in the control rats or in rats treated with lower doses of the compounds.

Amines↗

A test of the carcinogenicity of enflurane, isoflurane, halothane, methoxyflurane, and nitrous oxide in mice.

We exposed Swiss ICR mice for 2-hour periods to 1/32, 1/8 and/or 1/2 MAC enflurane, halothane, isoflurane, methoxyflurane, or N2O both in utero during the last 1/2 of pregnancy (4 exposures at 2-day intervals) and after delivery (24 exposures at 2-to-3-day intervals). Anesthetics were delivered in air or in O2. Thus, 1973 mice were exposed and examined after 15 months of life for the development of neoplastic lesions. Neoplastic lesions (principally pulmonary adenomas, lymphomas, hepatocyte lesions, liver vascular lesions) were found in all treatment and control sets. There was no indication that a specific anesthetic or anesthetic dose was carcinogenic. Our results do not confirm the suggestion that isoflurane is a hepatocarcinogen, nor do our data suggest that the modern inhaled anesthetics pose a significant threat of carcinogenicity.

Anesthesia, Inhalation↗