[Periprosthetic knee infection after a cat bite]. / Periprothetische Kniegelenkinfektion nach Katzenbiss.

BACKGROUND: Infections caused by Pasteurella multocida are extremely rare in arthroplasty. We report the case of a patient who was bitten by his domestic cat, causing an infection of his knee arthroplasty. DIAGNOSIS AND TREATMENT: The puncture of the knee resulted in putrid joint effusion. After removal of the knee prosthesis, infection with Pasteurella multocida was verified. We performed a two-stage revision combined with intravenous antibiotic therapy. DISCUSSION: Infections caused by cats and dogs should attract more attention especially as prosthesis material represents a significant "locus minoris resistentiae". Patients with domestic pets should be informed about this source of infection and possible complications. In the case of a bite, prompt and liberal antibiotic treatment should be administered.

Mild vitamin A deficiency leads to inborn nephron deficit in the rat.

BACKGROUND: Vitamin A plays a critical role in fetal organogenesis, and its severe deficiency during pregnancy is known to result in malformations of several organs, including the kidney. However, the consequences of mild vitamin A deficiency (VAD) has received little attention. In the present study, we examined the effect of in utero exposure to mild VAD on renal organogenesis. METHODS: A rat model of mild VAD compatible with normal gestation was developed. Plasma retinol was determined by reverse phase HPLC in mothers and fetuses. Nephron counting was performed in kidneys of fetuses and pups issued from control and VAD mothers. Metanephroi explanted from 14-day-old fetuses from both groups were cultured in the presence or absence of retinoic acid (RA), and growth and differentiation were assessed. c-ret expression was analyzed from fetuses exposed in utero to VAD or to normal vitamin A status and also in metanephroi grown in culture with or without RA using RT-PCR. RESULTS: The 50% reduction in circulating vitamin A levels induced by vitamin A deprivation in pregnant rats did not affect the overall fetal development. However, the number of nephrons was reduced by 20% in 21-day-old VAD fetuses. The number of nephrons was closely correlated with circulating vitamin A level in both VAD and control fetuses. Metanephroi taken from VAD fetuses developed to a lesser extent in vitro, but their capacity to respond to exogenous retinoic acid was not altered. Finally, we found that the expression of the proto-oncogene c-ret was modulated according to the retinoid environment. CONCLUSION: We conclude that vitamin A supply to the fetus is critical in determining the number of nephrons. Data available thus far on the frequency of mild VAD during pregnancy and on the long-term consequences of inborn nephron deficit highlight the clinical relevance of the present study.

Dual guiding catheters for saphenous venous graft protection during native coronary angioplasty.

The simultaneous use of two guiding catheters during angioplasty has been previously described for native coronary artery bifurcation lesions. We describe a case in which a dual guiding catheter, dual guidewire technique is used for angioplasty of a native vessel lesion spanning the anastomotic site of a sequential saphenous vein graft.

Cholesterol emboli in a colonic polyp.

Cholesterol emboli usually occur after vascular surgery or angiographic procedures in patients with extensive arteriosclerosis. Atheroemboli also occur spontaneously in patients receiving anticoagulant drugs. Ischemic colitis, gastric hemorrhage, and acute pancreatitis are the more common gastrointestinal manifestations of cholesterol emboli. Here I report, for apparently the first time, cholesterol emboli in a colonic polyp.

Effect of maternal hyperglycemia on NaK ATPase activity in fetal rat kidney.

The effect of moderate hyperglycemia on renal ATP production and ATPase activity of rat fetus was investigated using the experimental procedure of maternal continuous infusion of glucose during the last 5 days of gestation. Glucose-infused mothers and their fetuses showed a high level of glycemia (8.8 and 5.5 mM, respectively) and a high level of insulinemia (3 times higher than in controls). No change in either ATP or ADP concentration was detectable but an increase in NaK ATPase activity occurred without any change in Mg ATPase activity. These modifications should be the result of an enhanced Na/glucose cotransport leading to an enhanced extrusion of Na at the basolateral membrane. These results indicate that immature kidney is able to increase NaK ATPase activity to maintain Na homeostasis.

Mitochondrial activity of rat kidney during ontogeny.

The development of oxidative metabolism was studied from the late fetal to adult stages in mitochondria isolated from rat kidney. We used the oxygen consumption rate, as an index of inner membrane activity and citrate synthase and fumarase activities as an index of matrix activity and cytochrome c oxidase activity as an index of the number of mitochondria. Fumarase and citrate synthase activities displayed different developmental patterns, suggesting that these Krebs cycle enzymes did not mature synchronously. In fetal mitochondria, net oxygen consumption measured in the presence of succinate or glutamate as substrate, was low; it increased during the day after birth and reached adult level between days 10 and 15. During this period, the levels of citrate synthase and cytochrome c oxidase activity did not change significantly in the isolated mitochondrial fraction. However, in fetal and adult kidney homogenates, these levels increased four-fold, suggesting a corresponding increase in the number of mitochondria. Most of these increases occurred during the 15 days after birth. These results suggest that in rat kidney, mitochondrial maturation precedes the maturation of reabsorptive ion transport and does not limit its development.

Cholesterol emboli syndrome following cardiac catheterization.

Cholesterol emboli syndrome should always be considered in an elderly patient with acute renal failure or cutaneous lesions following an invasive vascular procedure or surgery. Laboratory findings that suggest atheroemboli include eosinophilia, an elevated erythrocyte sedimentation rate, leukocytosis, and anemia. Diagnosis is made by biopsy of the affected organ, and treatment is supportive. Patients usually die of multisystem failure.

Effects of birth on energy metabolism in the rat kidney.

The oxygen-consumption rates and the activities of fumarase and beta-hydroxyacyl-CoA dehydrogenase were compared in mitochondria isolated from fetal- and neonatal-rat kidney. Whole-organ ATP, phosphocreatine and creatine contents were determined in parallel. Kidney mitochondrial respiratory rates in the presence of succinate, glutamate/malate and palmitoyl-L-carnitine increased between 21 days post coitum and 1 day post partum, together with activities of oxidative enzymes. However, this postnatal maturation of oxidative metabolism was not yet initiated in mitochondria isolated from kidney 1 h post partum. An increase in ATP and phosphocreatine was observed immediately after delivery; newborn-rat kidney ATP content then remained high, whereas phosphocreatine reserves decreased considerably between 6 h and 1 day post partum. It is concluded that the increase in high-energy phosphate compounds observed at birth is not initially related to an activation of oxidative phosphorylation, and probably involves a transient stimulation of anaerobic glycolysis, while a progressive mitochondrial maturation takes place in the rat kidney during the first day of newborn life.