Intrarenal teratoma in a newborn child

A case of intrarenal teratoma in a newborn child is reported. The scarcity as well as the clinical and radiological signs of this lesion are emphasized and the difficulties to distinguish it from a nephroblastoma are analyzed. Solid intrarenal tumours in the infant and the newborn child are in nearly all cases nephroblastomas. All other types of solid tumours (benign or malignant) are exceptional. This induces us to report the present case.     

Functional interactions between nucleotide binding domains and leukotriene C4 binding sites of multidrug resistance protein 1 (ABCC1)

Multidrug resistance protein 1 (MRP1) is a member of the "C" branch of the ATP-binding cassette transporter superfamily. The NH(2)-proximal nucleotide-binding domain (NBD1) of MRP1 differs functionally from its COOH-proximal domain (NBD2). NBD1 displays intrinsic high-affinity ATP binding and little ATPase activity. In contrast, ATP binding to NBD2 is strongly dependent on nucleotide binding by NBD1, and NBD2 is more hydrolytically active. We have demonstrated that occupancy of NBD2 by ATP or ADP markedly decreased substrate binding by MRP1. We have further explored the relationship between nucleotide and substrate binding by examining the effects of various ATP analogs and ADP trapping, as well as mutations in conserved functional elements in the NBDs, on the ability of MRP1 to bind the photoactivatable, high-affinity substrate cysteinyl leukotriene C(4) (LTC(4))(.) Overall, the results support a model in which occupancy of both NBD1 and NBD2 by ATP results in the formation of a low-affinity conformation of the protein. However, nonhydrolyzable ATP analogs (beta,gamma-imidoadenosine 5'-triphosphate and adenylylmethylene diphosphonate) failed to substitute for ATP or adenosine 5'-O-(thiotriphosphate) (ATPgammaS) in decreasing LTC(4) photolabeling. Furthermore, mutations of the signature sequence in either NBD that had no apparent effect on azido-ATP binding abrogated the formation of a low-affinity substrate binding state in the presence of ATP or ATPgammaS. We suggest that the effect of these mutations, and possibly the failure of some ATP analogs to decrease LTC(4) binding, may be attributable to an inability to elicit a conformational change in the NBDs that involves interactions between the signature sequence and the gamma-phosphate of the bound nucleotide.     

Thromboprophylaxis in neurosurgery and head trauma

The incidence of deep vein thrombosis (DVT) is between 20 and 35% using contrast venography, with a rate of symptomatic DVT between 2.3 and 6% in neurosurgery without any prophylaxis. The risk of DVT is poorly evaluated in head injured patients but is around 5%. Specific risk factors in neurosurgery are: a motor deficit, a meningioma or malignant tumour, a large tumour, age over 60 years, surgery lasting more than 4 hours, a chemotherapy. The benefit of mechanical methods or low molecular weight heparin (LMWH) for the prevention of DVP in neurosurgery is demonstrated (grade A). Each method decreases the risk by about 50%. A postoperative prophylaxis with a LMWH does not seem to increase the risk of intracranial bleeding (grade C). There is no demonstrated benefit to begin a prophylaxis with LMWH before the intervention. The duration of the prophylaxis is 7 to 10 days but this has not been scientifically determined.     

Scintigraphic diagnosis of tricuspid regurgitation

The authors describe a simple technique for diagnosis of tricuspid regurgitation. Red blood cells were labeled in vivo with 99mTc and 22 patients were studied with ECG-gated blood-pool imaging of the liver. A single region of interest was manually drawn around the liver and a time-activity curve obtained. The per cent change in liver counts during the cardiac cycle was found to be significantly higher in the 12 patients with tricuspid regurgitation (Group I) (mean, 4.04 +/- 1.6%; range, 1.3-21.4%) compared with the 10 controls (Group II) (mean, 0.35 +/- 0.16%; range, 0.013-1.3%) (p less than 0.05). Using a 1% change in liver counts as the criterion of a positive study, all 12 cases in Group I were diagnosed correctly, but there was one false positive in Group II; thus the sensitivity was 100% and the specificity 90%.     

Histocompatibility leukocyte antigen-D related expression is specifically altered and predicts mortality in septic shock but not in other causes of shock

Although the expression of monocyte histocompatibility leukocyte antigen (HLA)-DR has been shown to be decreased during human sepsis, its level of expression in other nonseptic critical conditions is unclear. The aim of this study was to compare the level of HLA-DR expression on circulating monocytes among patients with septic, hemorrhagic, and cardiogenic shocks and severe sepsis without shock. At admission, HLA-DR expression was exclusively decreased in patients with septic shock (n = 30; P < 0.001), whereas the expression was similar between the other studied groups: cardiogenic shock (n = 16), hemorrhagic shock (n = 11), severe sepsis without shock (n = 18), and healthy volunteers (n = 8). HLA-DR expression was not predictive for overall mortality, but at day 1, an HLA-DR expression of less than 14 of mean fluorescence intensity (that corresponds to 40% labeled monocytes) was predictive of mortality exclusively in patients with septic shock (odds ratio, 11.4 and 95% confidence interval, 1.7; 78.4; P < 0.008). Catecholamine infusion, mechanical ventilation, positive blood culture, and number of units of blood or plasma transfused did not correlate with decreased HLA-DR expression. Thus, the decrease in HLA-DR expression is specific to septic shock and is associated, in septic shock patients, with increased mortality risk.     

High incidence of myocardial ischemia during postpartum hemorrhage

BACKGROUND: Postpartum hemorrhage remains a major cause of global maternal morbidity and mortality, even in developed countries, despite the use of intensive care units. This study sought to (1) assess whether myocardial ischemia could be associated with and even aggravate hemorrhagic shock in young parturients admitted for postpartum hemorrhage, and (2) identify the independent risk factors for myocardial ischemia. METHODS: On their referral to the intensive care unit, a multidisciplinary team managed parturients with severe postpartum hemorrhage. Ventilation, transfusion, catecholamines, surgery, or angiography with uterine embolization were provided as clinically indicated. Plasma cardiac troponin I levels were used as a surrogate marker of acute myocardial injury and electrocardiograms of myocardial ischemia. RESULTS: A total of 55 parturients were referred with severe postpartum hemorrhage, all in hemorrhagic shock. Twenty-eight parturients (51%) had elevated serum levels of cardiac troponin I (9.4 microg/l [3.7-26.6 microg/l]), which were associated with electrocardiographic signs of ischemia and deteriorated myocardial contractility and correlated with the severity of hemorrhagic shock. Indeed, multivariate analysis identified low systolic and diastolic arterial blood pressure (< 88 and < 50 mmHg, respectively) and increased heart rate (> 115 beats/min) as independent predictors of myocardial injury. In addition, all patients who were given catecholamines also had elevated cardiac troponin I levels. CONCLUSIONS: These results suggest that treatment of postpartum hemorrhage-induced hemorrhagic shock should be coupled with concomitant prevention of myocardial ischemia, even in young parturients.     

The effects of prolonged ambulation on labor with epidural analgesia

Ambulation during labor is becoming more popular, although its impact on the progress of labor and on pain intensity remains unclear. We wondered whether prolonged ambulation with epidural analgesia had a possible effect on duration of labor and pain. In this prospective, randomized trial, 61 parturients with uncomplicated term pregnancies were allocated to be recumbent (n = 31) or to ambulate (n = 30). Epidural analgesia was provided with intermittent administrations of 0.08% bupivacaine-epinephrine plus 1 microg/mL of sufentanil. Of the 30 women assigned to the ambulatory group, 25 actually walked. Their ambulating time was 64 +/- 34 min (mean +/- SD), i.e., 29% +/- 16% of the first stage. There were no differences between the two groups in the length of labor and in pain visual analog scale scores. However, the ambulatory group received smaller doses of bupivacaine (6.4 +/- 2.2 mg/h versus 8.4 +/- 3.6 mg/h; P = 0.01) and of oxytocin (6.0 +/- 3.7 mUI/min versus 10.2 +/- 8.8 mUI/min; P < 0.05). A greater ability to void was also found in the ambulatory group (P < 0.01). Although the duration of labor and pain relief was unchanged, these findings support that ambulation during labor may be advantageous. IMPLICATIONS: This study compared the duration of labor and pain relief between parturients receiving epidural analgesia who were ambulated or were recumbent. Whereas walking had no impact on either duration of labor or pain relief, it was associated with a reduction in both bupivacaine and oxytocin requirements.     

Assessment of vascular reactivity in rat brain glioma by measuring regional blood volume during graded hypoxic hypoxia

While morphological and molecular events during angiogenesis in brain glioma have been extensively studied, the functional properties of tumour vessels have yet received little attention. We have determined changes in regional blood volume (BV) during graded hypoxic hypoxia using susceptibility contrast magnetic resonance imaging in a model of rat brain glioma. Nine anaesthetised and ventilated rats with C6 glioma were subjected to incremental reduction in the fraction of inspired oxygen (FiO(2)): 0.35, 0.25, 0.15, 0.12, 0.10 and reoxygenation to 0.35. At each episode, BV was determined in peritumoral, intratumoral and contralateral regions. Baseline BV values (FiO(2) of 0.35) were higher in peritumoral than in the contralateral and intratumoral regions. Progressive hypoxia resulted in a graded increase in BV in contralateral and peritumoral regions. At FiO(2) of 0.10, BV increases were comparable between these two regions: 49+/-22% (s.d.) and 28+/-17% with respect of control values, respectively. These BV changes reversed during the reoxygenation episode. By contrast, the intratumoral region had a significant increase in BV at FiO(2) of 0.10 only, with no evidence of return to the basal value during reoxygenation. Immunohistochemical staining of alpha-smooth muscle actin confirmed reactivity of vessels in the peritumoral region. Our findings indicate that peritumoral vessels present a vascular reactivity to hypoxia, which is comparable to that of nontumoral vessels. A method is thus available for noninvasively demonstrating whether any particular vascular modifying strategy results in the desired outcome in terms of tumour blood volume changes.