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A 4-year-old boy had severe hypertension, cardiac failure, and signs of neurofibromatosis. Arteriography disclosed renal artery stenosis in both kidneys with signs of ischemia, particularly in the right kidney. Because of insufficient response to antihypertensive therapy, a right-sided nephrectomy was performed. Histological examination of this kidney showed segmental stenosis in all branches of the renal artery. The vascular lesions were characterized by an intimal proliferation of spindle cells in a mucoid matrix with destruction of the internal elastic membrane frequently accompanied by loss or attenuation of the media and fibrosis of the adventitia. Occasionally, a nodular arrangement of the spindle cells at the interface between intima and media was observed. Immunohistochemical studies demonstrate a smooth-muscle cell origin for these cells.

Hypothyroidism diminishes proteinuria and prolongs survival in several immune models of progressive renal failure. In the well-characterized non-immune model of 5/6 nephrectomy we studied the effects of thyroidectomy (Tx) on the development of proteinuria and glomerulosclerosis (GS). Hypothyroidism was confirmed by lower values of thyroxine in Tx rats compared to sham Tx rats at 9 weeks (12.6 +/- 6.7 nmol/l Tx versus 37.7 +/- 10.8 nmol/l sham Tx) and 12 weeks after operation (7.2 +/- 4.9 nmol/l Tx versus 14.4 +/- 4.1 nmol/l sham Tx). Tx resulted in a reduction in mean arterial blood pressure and proteinuria and a lower incidence of GS (4.2 +/- 3.1% Tx versus 17.1 +/- 10.0% sham Tx) 12 weeks after nephrectomy, along with a decrease in food intake (104 +/- 13 g/week Tx versus 138 +/- 10 g/week sham Tx). In the same experiment a third group of sham Tx rats was pair fed to the Tx rats, resulting in values similar to those of Tx rats for proteinuria and the incidence of GS (6.0 +/- 4.9% pair fed sham Tx). Thyroxine levels at 9 and 12 weeks were comparable to those in sham Tx rats fed ad libitum. No association was found between the incidence of GS and glomerular volume. Studies of the inulin clearance in a second set of experiments showed that glomerular filtration rate and renal plasma flow are lower in hypothyroid rats compared to sham Tx rats. We conclude that hypothyroidism has a renal protective effect due to a decrease in food intake resulting in alterations in renal haemodynamics.

Acute Q-fever is a systemic illness which rarely has a fatal outcome. Fatal cases do occur with the chronic form of the disease and associated with endocarditis. This report presents the case of a fatal, acute Q-fever pneumonia in an 11-year-old patient with chronic granulomatous disease. Complement fixation antibody titer rose to 1:1,024 with positive IgM in immunofluorescence. Giemsa stained lung sections and indirect immunofluorescence demonstrated the microorganisms in the tissues. The Coxiella burnetii infection was probably contracted during a holiday trip to rural France. Despite the fact that the patient received a variety of antimicrobial agents with broad spectrum activity against bacteria and fungi, coverage for Q-fever, i.e. chloramphenicol or tetracyclines, was not included.

The effect of uninephrectomy (UN) at 4 months of age was studied on several parameters involved in the development of glomerulosclerosis (GS) in male spontaneously hypertensive Fawn-Hooded rats. Protein excretion per animal was significantly more increased in UN rats at 2 months after operation compared to sham operated controls (202 +/- 104 vs. 88 +/- 37 mg 24 h-1, P = 0.005) and remained significantly higher throughout the rest of the observation period. At 11 months of age UN rats had a marked increase in the incidence of GS, 37 +/- 16% compared to 5 +/- 3% (P less than 0.001) in controls. No differences were observed in mean arterial blood pressure. Functional studies in separate groups of rats at 5 months of age showed an increase in single kidney glomerular filtration rate in UN rats (0.40 +/- 0.07 vs. 0.28 +/- 0.09 ml min-1 100 g, P = 0.006). Single kidney renal plasma flow and filtration fraction were not altered. Mean glomerular volume was increased 1 month after UN (1.86 +/- 0.25 vs. 1.39 +/- 0.25 x 10(6) microns 3, P = 0.003). Urinary noradrenaline excretion per animal (24-h) showed a high sympathic nervous tone in both sham and UN rats. Total urinary dopamine and kallikrein excretion per animal were not influenced by UN. These data indicate that after UN the development of GS in this rat strain is accelerated in association with compensatory hyperfiltration and glomerular volume expansion, which may play a role in the pathogenesis of GS.

Objective: To determine the effect of angiotensin converting enzyme inhibition (CEI) upon renal function and the incidence of glomerulosclerosis in spontaneously hypertensive Fawn Hooded rats (FHR)., Design: Male FHR were treated with captopril from the age of 5 months when mild hypertension, proteinuria and glomerulosclerosis are present, and sacrificed at 12 months of age. Renal function was determined in separate groups of FHR at 6 months of age., Methods: Proteinuria, body weight and systolic blood pressure were determined at regular intervals. Blood pressure was measured by the tail-cuff method. Kidneys were prepared for histological examination by standard methods. Renal function was determined by inulin clearance and urinary kallikrein by an amydolitic assay., Results: In untreated FHR blood pressure, proteinuria and glomerulosclerosis increased with time. Captopril normalized blood pressure and stabilized proteinuria at pretreatment levels. At the end of the study, the incidence of glomerulosclerosis was significantly lower and comparable with the incidence at 5 months. Glomerular volume did not show a correlation with the incidence of glomerulosclerosis. Hemodynamic studies showed a significant increase of glomerular filtration rate in captopril-treated rats. No statistically significant effect was seen on renal plasma flow or filtration fraction. Urinary excretion of kallikrein was increased in captopril-treated rats., Conclusions: CEI is effective in protecting the kidney from structural damage in hypertensive FHR even when treatment is started under conditions of established glomerular injury. The protection given by captopril is probably related to intrarenal effects.

Genetically determined differences in functional and structural determinants that govern the development of progressive glomerulosclerosis (GS) were studied in aging sham-operated or unilaterally nephrectomized male rats of two strains. Wistar rats showed an increase of proteinuria and GS with age, which was enhanced by unilateral nephrectomy (UN). In contrast, intact and UN Wistar Kyoto rats did not show an increase of proteinuria with age and 7 months after UN, no GS was seen in these rats. Systemic blood pressure was comparable in both strains and was not affected by UN. Functional studies in a separate group of rats 1 month after UN showed an identical increase in glomerular filtration rate in both strains as compared with sham-operated controls. The Wistar rats did not show an effect of UN on renal plasma flow, and consequently, there was an increase in filtration fraction, in contrast to Wistar Kyoto rats, which showed an increase in renal plasma flow with an unchanged filtration fraction. Glomerular volume was increased in both strains at 1 month and 7 months after UN. Mesangial expansion was not observed at 1 month after UN in either strain, which indicates that this is not a decisive factor in the development of GS. These data indicate that the genetically determined susceptibility to the development of GS in these two rat strains may be related to the degree of vasoconstriction, whereas glomerular volume expansion per se does not lead to GS but can well be a consequence of hyperfiltration. These studies are concordant with previous studies that revealed the role of hemodynamics in the pathogenesis of GS irrespective of glomerular expansion.

Proteins characteristic for the adult cellular phenotype, i.e., carbamoylphosphate synthetase (CPS) for liver and small intestine, arginase for liver, glutamate dehydrogenase (GLDH) for pancreas, liver, and small intestine, and amylase for pancreas were studied immunohistochemically in rat embryos and fetuses. At distinct developmental stages, subsets of enzymes appear synchronously in the foregut derivatives, suggesting that gene expression in the different organs is regulated by common factors. In contrast to the long-held opinion that fetal hepatocytes are a homogeneous cell population, it is shown that arginase and CPS are heterogeneously distributed between ED 16 and ED 20. This heterogeneity is related to the vascular architecture of the liver and disappears perinatally as the result of strong stimulation of enzyme synthesis. In addition, an intercellular heterogeneity in CPS content that is not related to the vasculature is observed between ED 14 and ED 20. This "random" heterogeneity reflects temporal differences in the onset of CPS accumulation in individual cells.

In monolayer cultures, hepatocyte-specific enzymes are inducible by hormones as soon as hepatocytes differentiate from the embryonic foregut (15-somite stage). Though offering an excellent opportunity for quantitative studies, several features of a normal cell environment are lost in such a model system. To determine the inducibility of such tissue-specific enzymes in intact organisms, rat embryos were cultured in vitro for 48 h and exposed to the hormonal factors that had been found effective in monolayer culture, viz. dexamethasone, triiodothyronine and dibutyryl cyclic AMP. Normal development of the embryos during culture in vitro was assessed by general criteria reflecting growth, morphogenesis and cytodifferentiation. Development of external features, organogenesis, the distribution of cell divisions and the appearance of tissue-specific proteins such as alpha-fetoprotein and glutamate dehydrogenase served as parameters. Despite undisturbed development of the embryos as judged by these criteria, irrespective of whether the culture was started at day 10 or at day 11 of gestation (just before, respectively after the appearance of the liver primordium), induction of hepatocyte-specific enzymes like carbamoylphosphate synthetase by hormones could not be demonstrated immunohistochemically. However, induction of this enzyme by hormones could be demonstrated in monolayers of hepatocytes isolated from such embryos after 48 h of culture, providing yet another demonstration of the adequate culture conditions. In addition, an adequate uptake of hormones by the embryo during culture could be shown with radio-actively labeled dexamethasone and triiodothyronine and with a radioreceptor assay for cyclic AMP. Therefore, the presence of factors in young embryos that inhibit tissue-specific enzyme synthesis has to be postulated.