Validation in the sheep of an ultrasound velocity dilution technique for haemodialysis graft flow

BACKGROUND: A simple, rapid, inexpensive method for measuring the flow in a patient's vascular access would permit routine monitoring during haemodialysis, and hence provide information of access graft deterioration sufficiently early to increase the success of minimally invasive remedial procedures. This paper reports the validation of such a method in animals. METHODS: A PTFE graft was implanted in sheep between the carotid artery and the jugular vein. While the sheep was under general anaesthesia and on an haemodialysis circuit, ultrasound velocity in its blood was perturbed by the injection of a 5-10 ml bolus of isotonic NaCl. The pump tubing flow was measured by a transit-time blood flow meter. This flow was combined with the areas of perturbation generated by the injection before and after mixing in the access flow to estimate graft flow. The calculated graft flow was compared to flow measured directly by a transit-time probe on the same carotid artery. RESULTS: Over a 10-fold range, 120-1260 ml/min, graft flow measured by ultrasound velocity dilution agreed well with graft flow measured directly with a scatter of 76 ml/min about the regression line. CONCLUSION: Ultrasound velocity dilution provides a method for measuring flow in the graft accurate enough for clinical evaluation of patients on dialysis.      

Combination of ABO blood group incompatibility and glucose-6-phosphate dehydrogenase deficiency: effect on hemolysis and neonatal hyperbilirubinemia

The incidence (%) of hyperbilirubinemia (serum bilirubin ≥257 μmol/l) was similar in neonates with a combination of ABO incompatibility and glucose-6-phosphate dehydrogenase (G-6-PD) deficiency (45%), with ABO incompatibility (54%) or G-6-PD deficiency (37%), alone (ns). Carboxyhemoglobin values, corrected for inspired CO, were similarly elevated in all three groups (0.87 ± 0.32%, 0.82 ± 0.29%, 0.76 ± 0.18%, respectively, ns), but correlated with bilirubin only in those with ABO incompatibility alone. ABO-incompatible/G-6-PD-deficient neonates, compared with those with either condition alone, are not at increased risk for hemolysis or hyperbilirubinemia.     

Solitary plasmacytoma of the spine. Long-term clinical course

The data for 19 patients with solitary plasmacytoma of the spine were reviewed with regard to clinical course and prognosis (median follow-up, 96 months). Eight patients presented with spinal cord compression. A monoclonal immunoglobulin was initially detected in seven of 15 evaluable patients. Treatment included radiotherapy (18 of 19) and/or surgery (11 of 19) and chemotherapy (eight of 19). Spinal cord compression was reversed in every patient. The expected survival rate was 85% at 10 years after diagnosis. Local recurrence or dissemination was observed in 13 patients. It occurred within 5 years of diagnosis in 11 patients and was localized (that is, local recurrence or single bone metastasis) in eight patients. It was always associated with the appearance or an increase of the M component. Dissemination frequently had a "metastatic" pattern with no diffuse bone marrow plasmacytosis. The incidence of local recurrence (five patients) and leukemia (four patients) was high. Local recurrence and/or dissemination were significantly more frequent in patients with the M component at diagnosis than in those without it (P less than 0.05; relative risk, R = 4). The effectiveness of surgery and chemotherapy combined with radiotherapy is also discussed.     

Induction of a differentiated ciliated cell phenotype in primary cultures of Fallopian tube epithelium

Human Fallopian tubal epithelial cells in culture lose morphological features associated with the epithelium in situ and the extent to which they retain their in-vivo phenotype or function is unknown. In order to address this question, immunocytochemical markers were identified which distinguish secretory (HMFG2+, LhS28-) from ciliated (HMFG2-, LhS28+) epithelial cells in tissue sections of Fallopian tube. These markers were used to analyse the phenotype of tubal cells in vitro. Primary cultures of human tubal epithelial cells were seeded onto glass and grown to confluence before addition of oestradiol-17beta. In the absence of hormone, tubal epithelial cells expressed cytokeratins and nuclear receptors for oestrogen and progesterone and adopted a homogeneous (HMFG2+, LhS28-) secretory cell phenotype. Following the addition of oestradiol-17beta, a proportion of cells became positive for LhS28. The induction of a ciliated epithelial cell phenotype was confirmed by scanning electron microscopy, where on permeable collagen membranes, approximately one-third of tubal epithelial cells became ciliated in the presence of oestradiol-17beta. We suggest that in vitro, tubal epithelial cells adopt an immature secretory-like phenotype and that oestrogen can induce differentiation to a ciliated epithelial cell phenotype.      

Pseudophakia and aptitude of aviation personnel]

Because of sensorial disruptions, aphakia post-cataract surgery is a cause of unfitness for the job of aeronautics flying personnel. Its correction thanks to intraocular lenses and a correct functional check-up permit to reconsider the fitness through a derogation given by the competent authorities. EQUIPMENT AND METHODS: The authors realized a retrospective study on the 5 last years. 27 flying personnel, 24 to 76 years old, went through a cataract surgery with implantation. The check-up includes a chemical exam completed by a morphoscopic, coloured and spatial study. RESULTS AND DISCUSSION: The files are more or less well-documented according to their origin. The flying personnel have an average of 4,010 flying hours. The average post-operative hindsight is 30 months. 3 wear intraocular lenses of rear chamber among which 1 is multifocal. 7 were examinated at the CPEMPN with satisfying morphoscopic, coloured and luminous sense compatible with the fitness. 4 are declared permanent unfit (1 professional pilot with bad results, 1 private pilot with other pathologies, 1 inexperienced stewardess getting through the admission visit with insufficient post-operative hindsight, 1 professional pilot declared unfit for its military activity in the reserve). 4 are qualified with restriction. 20 are qualified without restriction. CONCLUSION: The correction of aphakia with intraocular lenses permits in most cases to obtain good functional results compatible with the flying aptitude.     

Cytokeratin 7 and 20 expression in cholangiocarcinomas varies along the biliary tract but still differs from that in colorectal carcinoma metastasis

In the liver, the immunostaining of cytokeratins (CK) 7 and 20 has been used to distinguish usual peripheral cholangiocarcinomas (CC) and colorectal carcinoma metastasis (CRM). However, other subtypes of CC are not infrequent and may be particularly difficult to distinguish from CRM by histology and even immunohistochemistry. Therefore, 48 CC from different locations, either peripheral (n = 19), or nonperipheral, that is, from the large intrahepatic bile ducts, the hilum, and the extrahepatic bile ducts (n = 29), and with different cytoarchitectural patterns were tested for CK7 and CK20 and compared with 31 CRM. CC were positive for CK7 and CK20 in 96% and 70%, respectively, whatever the architecture and differentiation of the tumor. The labeling index (LI) of CK7 in CC was always high, whereas it was low or moderate for CK20. CK20-positive phenotype was significantly more frequent in nonperipheral than in peripheral CC (82% vs 47%; p = 0.007). CRM were all positive for CK20 with a high LI, and mostly negative (81%) for CK7. In conclusion, (1) the CK immunoprofile of CC varies according to the location of the tumor in the biliary tract, peripheral CC being more often CK7+/CK20-, and nonperipheral ones CK7+/CK20+; and (2) a decision tree based on CK20 LI and CK7 positivity allows the distinction of CRM and CC, even for the nonperipheral type.     

Estrogenic and antiproliferative activities on MCF-7 human breast cancer cells by flavonoids

The interaction between the estrogen receptor and a variety of flavonoids was studied in the presence or absence of estradiol using a stably-transfected human breast cancer cell line (MVLN). On the other hand, flavonoids were evaluated for their effects on proliferation in estrogen-dependent (MCF-7) and independent (MDA-MB231) human breast cancer cells. We established a relationship structure-activity and determined regions and/or substituents essential for estrogenic or antiestrogenic activities. In contrast, we did not find the same relationship for cell proliferation. Among all flavonoids used, only 7-methoxyflavanone and 7,8-dihydroxyflavone at high concentrations (50 μM) possess antiestrogenic and antiproliferative activities. These results suggest that two hydroxyls (in positions 7 and 8) or 7-methoxy substituents are essential for the antiestrogenic activity of flavonoids. However, it seems that flavonoids at high concentrations exert their antiproliferative activity through other estrogen receptor-independent mechanisms.     

Experimentelle Spondylodese der Schafshalswirbelsäule Teil 1: Der Effekt des Cage-Designs auf die intervertebrale Fusion

INTRODUCTION: There has been a rapid increase in the use of interbody fusion cages as an adjunct to spondylodesis, although experimental data are lacking. A sheep cervical spine interbody fusion model was used to determine the effect of different cage design parameters (endplate-implant contact area, maximum contiguous pore) on interbody fusion. MATERIAL AND METHOD: IN VITRO EVALUATION: 24 sheep cadaver specimens (C2-C5) were tested in flexion, extension, axial rotation, and lateral bending with a nondestructive flexibility method using a nonconstrained testing apparatus. Four different groups were examined: (1) control group (intact) ( n=24), (2) autologous tricortical iliac crest bone graft ( n=8), (3) Harms cage ( n=8), and (4) SynCage-C ( n=8). IN VIVO EVALUATION: 24 sheep underwent C3/4 discectomy and fusion: group 1: autologous tricortical iliac crest bone graft ( n=8), group 2: Harms cage filled with autologous cancellous iliac crest bone grafts ( n=8), and group 3: SynCage-C filled with autologous cancellous iliac crest bone grafts ( n=8). Radiographic scans were performed pre- and postoperatively and after 1, 2, 4, 8, and 12 weeks, respectively. At the same time points, disc space height (DSH), height index (HI), intervertebral angle (IVA), and endplate angle (EA) were measured. After 12 weeks the animals were killed and fusion sites were evaluated using biomechanical testing in flexion, extension, axial rotation, and lateral bending. Additionally, histomorphological and histomorphometrical analyses were performed. RESULTS: Over a 12-week period the cage groups showed significantly higher values for DSH, HI, IVA, and EA compared to the bone graft. In vivo stiffness was significantly higher for the tricortical iliac crest bone graft and Harms cage than in vitro stiffness. However, there was no difference between in vitro and in vivo stiffness of the SynCage-C. Histomorphometrical evaluation showed a more progressed bone matrix formation in the Harms cage group than in both other groups. CONCLUSION: The parameter endplate-implant contact area was not able to determine subsidence of cages. In contrast, the maximum contiguous pore of a cage significantly correlates with interbody bone matrix formation inside the cage. Additionally, there was no correlation between in vitro and in vivo stiffness of interbody fusion cages. Therefore, biomechanical in vitro studies are not able to determine in vivo outcome of fusion cages. Animal experimental evaluations of interbody fusion cages are essential prior to clinical use.