Automated three-dimensional analysis of histological and autoradiographic rat brain sections: application to an activation study.

Besides the newly developed positron emission tomography scanners (microPET) dedicated to the in vivo functional study of small animals, autoradiography remains the reference technique widely used for functional brain imaging and the gold standard for the validation of in vivo results. The analysis of autoradiographic data is classically achieved in two dimensions (2D) using a section-by-section approach, is often limited to few sections and the delineation of the regions of interest to be analysed is directly performed on autoradiographic sections. In addition, such approach of analysis does not accommodate the possible anatomical shifts linked to dissymmetry associated with the sectioning process. This classic analysis is time-consuming, operator-dependent and can therefore lead to non-objective and non-reproducible results. In this paper, we have developed an automated and generic toolbox for processing of autoradiographic and corresponding histological rat brain sections based on a three-step approach, which involves: (1) an optimized digitization dealing with hundreds of autoradiographic and histological sections; (2) a robust reconstruction of the volumes based on a reliable registration method; and (3) an original 3D-geometry-based approach to analysis of anatomical and functional post-mortem data. The integration of the toolbox under a unified environment (in-house software BrainVISA, http://brainvisa.info) with a graphic interface enabled a robust and operator-independent exploitation of the overall anatomical and functional information. We illustrated the substantial qualitative and quantitative benefits obtained by applying our methodology to an activation study (rats, n=5, under unilateral visual stimulation).     

A randomized trial of low-protein diet in type 1 and in type 2 diabetes mellitus patients with incipient and overt nephropathy.

OBJECTIVE: The efficacy of a low-protein diet in the secondary prevention of diabetic nephropathy is not established in patients with type 1 or type 2 diabetes mellitus. To determine whether a low-protein diet slows the decrease in glomerular filtration rate (GFR) and decreases the albumin excretion rate (AER) in diabetic patients with incipient and overt nephropathy, we performed a 2-year prospective, randomized controlled trial comparing the effects of a low-protein diet (0.8 g/kg/day) with a usual-protein diet. SETTING AND PATIENTS: The study was conducted in a University hospital and included 63 type 1 and type 2 diabetic patients with either incipient or overt nephropathy and mild renal failure (prestudy GFR, 80 +/- 20 mL/min). The primary outcome measures were decreased in GFR and 24-hour AER. RESULTS: In the low-protein-diet group, patients were younger (52 +/- 12 versus 63 +/- 9 years old) and more often were type 2 diabetic. During the follow-up period, according to dietary records the low-protein-diet group consumed 16% +/- 3% of total caloric intakes as compared with 19% +/- 4% in the usual-protein-diet group (P < .02), but 24-hour urinary urea excretions did not differ between the two groups. The 2-year GFR decrease was 7 +/- 11 mL/min in the low-protein-diet group and 5 +/- 15 mL/min in the usual-protein-diet group (P = not significant). AER did not increase significantly in the two diet groups during the follow-up period. Blood pressure and glycemic control were similar in the two groups all along the study. The decrease in GFR and AER were also similar in 6 compliant patients according to dietary records and to 24-hour urinary urea excretions from the low-protein-diet group and in 12 patients from the usual-protein-diet group. CONCLUSIONS: A 2-year low-protein diet did not alter the course of GFR or of AER in diabetic patients with incipient or overt nephropathy receiving renin-angiotensin blockers with strict blood pressure control.     

Intra-abdominal packing for uncontrollable haemorrhage during ruptured abdominal aortic aneurysm repair.

OBJECTIVE: Intra-abdominal packing is a valuable adjunct in patients with abdominal trauma and uncontrollable bleeding but few data exist regarding early and late outcome associated with this technique in patients with ruptured abdominal aortic aneurysm (AAA). METHODS: Interrogation of a prospective vascular surgical database identified 23 patients (22 men; median age 69, range 59-82, years) with ruptured AAA who required intra-abdominal packing for control of coagulopathic haemorrhage after insertion of an aortic graft between January 1982 and December 2003. Co-morbidity, operative and outcome data were retrieved. RESULTS: Haemostasis was achieved and packs were removed within 48 h in 20 patients. In those patients who had a graft inserted, the peri-operative mortality rate was 12 of 23 (52%) patients (vs. 172 of 455 (38%) patients who were not packed, NS). Three (13%) patients developed early intra-abdominal sepsis, which was universally fatal: graft-enteric fistula, intra-abdominal abscess with necrotizing fasciitis of the abdominal wound, and infected retroperitoneal haematoma. Two of 11 (18%) survivors developed late graft-related infective complications: major aortic graft infection at 6 months and symptomatic infected para-anastomotic aortic false aneurysm at 39 months. Early and late intra-abdominal infective complications were significantly more common in patients who were packed than in those who were not (packed: five of 23, 22% vs. non-packed: five of 455, 1%; p < 0.001). CONCLUSION: These data demonstrate that intra-abdominal packing in coagulopathic patients with ruptured AAA can achieve an acceptable survival rate. However, this technique may be associated with an increased incidence of early and late intra-abdominal infective complications.     

Transforming growth factor alpha treatment alters intracellular calcium levels in hair cells and protects them from ototoxic damage in vitro

To determine if transforming growth factor alpha (TGFα) pretreatment protects hair cells from aminoglycoside induced injury by modifying their intracellular calcium concentration, we assayed hair cell calcium levels in organ of Corti explants both before and after aminoglycoside (i.e. neomycin, 10⁻³M) exposure either with or without growth factor pretreatment. After TGFα (500ng/ml) treatment, the intracellular calcium level of hair cells showed a five-fold increase as compared to the levels observed in the hair cells of control cultures. After ototoxin exposure, calcium levels in hair cells of control explants showed an increase relative to their baseline levels, while in the presence of growth factors pretreatment, hair cells showed a relative reduction in calcium levels. Pretreatment of organ of Corti explants afforded significant protection of hair cell stereocilia bundle morphology from ototoxic damage when compared to explants exposed to ototoxin alone. This study correlates a rise in hair cell calcium levels with the otoprotection of hair cells by TGFα in organ of Corti explants.     

RELATIONSHIP BETWEEN PLATELET CYTOSOLIC FREE CALCIUM CONCENTRATION AND PLASMA RENIN ACTIVITY

1. Plasma renin activity (PRA) and platelet cytosolic free calcium concentration ([Ca2+]i) were simultaneously determined in 18 untreated essential hypertensive subjects and 17 normotensive controls. A significant positive correlation was found between [Ca2+]i and PRA (slope = 42 nmol/l/ng/ml/h) in these 35 subjects. 2. Two determinations more than one week apart in nine subjects confirmed the parallel fluctuations of [Ca2+]i and PRA. A strict sodium restriction produced a progressive PRA elevation associated with a parallel rise in [Ca2+]i in one subject. 3. These results are consistent with the hypothesis that angiotensin II causes a concentration-dependent calcium mobilization.     

Lhermitte-Duclos disease

Lhermitte-Duclos disease (dysplastic gangliocytoma of the cerebellum) is a rare pseudo-neoplastic disorder of the cerebellum with typical MRI findings. A 25-year-old man presenting with progressive neck pain, dizziness, and impaired vision is reported. CT and MRI revealed a left cerebellar haemispheric mass and obstructive hydrocephalus. Lhermitte-Duclos disease was histologically confirmed after surgical removal of the lesion. The typical MRI appearance of a nonenhancing haemispheric cerebellar mass with preservation and exaggeration of the normal gyral pattern allows pre-operative diagnosis of this condition. The literature is reviewed and clinical presentation, radiology and histopathology are discussed.