Significance of Anticardiolipin Antibodies on Short and Long Term Allograft Survival and Function following Kidney Transplantation

The significance of anticardiolipin antibodies (ACAs) prior to renal transplantation is unclear. We studied a cohort of 337 patients who underwent renal transplantation from 1996 to 2001. Follow-up continued until allograft loss, patient death or 31 December 2002. The primary outcome was a composite endpoint of death-censored allograft loss or a 25% reduction in estimated glomerular filtration rate (GFR) from 1-month post-transplant. Secondary outcomes were allograft loss, a 25% reduction in GFR, acute rejection and creatinine at 1 year. IgG and IgM ACA titers were positive (> or =15) in 18.1% of recipients. There were no significant differences at baseline between recipients, except coumadin therapy in those with positive ACA titers (20% vs. 7.4%). Post-transplant, there was no increase in the primary outcome in ACA-positive patients, even after adjustment for anticoagulation with coumadin (HR = 1.42 [0.68, 2.96]). There was no difference in secondary outcomes between those with or without positive titers. Two of five patients with very high titers (>50) who were not anticoagulated had early graft loss. A positive ACA titer prior to kidney transplantation was not associated with inferior renal outcomes after transplantation, although more research is required to address the prognostic significance of very high ACA titers.     

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.      

The role of radiation therapy in the management of carcinoma of the male and female urethra.

Carcinoma of the urethra (male and female) is an unusual disease with insufficient clinical experience to be dogmatic about therapeutic recommendations. The onset is usually insidious, with a long interval from the first symptoms to diagnosis, yet lack of local and regional control remains the principal obstacle to cure. Treatment choices and results depend to a great degree on the extent, location, and stage of the lesion. Our conclusion is that good surgery and carefully planned irradiation are equally effective in the management of these tumors.     

Verbal Working Memory and Atherosclerosis in Patients with Cardiovascular Disease: An fMRI study

BACKGROUND AND PURPOSE: Intimal-medial thickening (IMT) of the carotid wall is an accepted peripheral marker of atherosclerosis. It is associated with increased risk for myocardial infarction and stroke, and lower attention-executive-psychomotor functioning. The purpose of this study was to examine the relationship between IMT and brain activity during a verbal working memory (VWM) task in patients with cardiovascular disease (CVD). METHODS: Thirteen CVD patients underwent functional magnetic resonance imaging (fMRI) during a 2-Back VWM task, and B-mode ultrasound of the carotid arteries. IMT was calculated using an automated algorithm based on a validated edge-detection technique. The relationship between IMT and 2-Back-related brain activity was modeled using partial correlations controlling for age and small vessel disease as measured by white matter signal hyperintensities on MRI (WMH). RESULTS: Higher IMT was associated with lower 2-Back-related signal intensity and in the right middle frontal gyrus, independent of age and WMH. CONCLUSIONS: IMT may be one mechanism contributing to brain dysfunction in CVD. The blood oxygenation level-dependent (BOLD) contrast appears to be highly sensitive to peripheral vascular health as measured by IMT. Future studies should examine the sensitivity and specificity of the BOLD response for predicting cognitive decline in CVD.     

Improved Assessment of Significant Activation in Functional Magnetic Resonance Imaging (fMRI): Use of a Cluster-Size Threshold

The typical functional magnetic resonance (fMRI) study presents a formidable problem of multiple statistical comparisons (i.e, > 10,000 in a 128 x 128 image). To protect against false positives, investigators have typically relied on decreasing the per pixel false positive probability. This approach incurs an inevitable loss of power to detect statistically significant activity. An alternative approach, which relies on the assumption that areas of true neural activity will tend to stimulate signal changes over contiguous pixels, is presented. If one knows the probability distribution of such cluster sizes as a function of per pixel false positive probability, one can use cluster-size thresholds independently to reject false positives. Both Monte Carlo simulations and fMRI studies of human subjects have been used to verify that this approach can improve statistical power by as much as fivefold over techniques that rely solely on adjusting per pixel false positive probabilities.     

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.     

Susceptibility of bovine macrophages to infectious bovine rhinotracheitis virus infection.

Infectious bovine rhinotracheitis virus replicated in cultured bovine alveolar macrophages (AM). However, yields of infectious virus were low, with maximum titers approximately 100 times that of the residual inoculum. Immunofluorescence and electron microscopic studies indicated that the majority of macrophages produced viral antigen, but after infection at a multiplicity of 0.1, only 4.1% of AM produced infectious centers. Virus-infected AM culture supernatants possessed interfering activity, probably due to interferon. Incubation of fresh AM with these fluids rendered them refractory to infection. Although AM from infectious bovine rhinotracheitis virus-immune and -susceptible donors were equally permissive and their susceptibility was unaltered by incubation with bacterial lipopolysaccharide, bovine mammary macrophages which were elicited with lipopolysaccharide became nonpermissive when further incubated for 48 h with 1 microgram of lipopolysaccharide per ml. Under these conditions, infected mammary macrophages failed to synthesize viral DNA, and there was reduced synthesis of "late" viral polypeptides.     

A comparison of fluorescein isothiocyanate and lissamine rhodamine (RB 200) as labels for antibody in the fluorescent antibody technique

The relative merits of fluorescein isothiocyanate (FITC) and lissamine rhodamine (RB 200) as labels for antibody in fluorescence microscopy were studied and compared by microphotometry, testing each fluorochrome under its own optimal conditions as far as possible, and at a similar range of dye:protein ratios. The antibody was sheep anti-human globulin, and the tissues stained with it were rat liver sections bearing human anti-nuclear factor on the nuclei. The findings were as follows:

(i) the amount of RB 200 conjugating with protein was strictly proportional to the amount of the sulphonyl chloride derivative added to the reaction mixture; with increasing amounts of FITC in the reaction mixture, however, there was a less than proportional increase in the degree of conjugation.

(ii) Diethylaminoethyl (DEAE)-cellulose chromatography decreased the dye:protein ratio of the conjugates by 40% uniformly for both RB 200 and FITC, regardless of the initial dye:protein ratio.

(iii) When corrections were made for spectral responses of photo-detectors, effects of optimizing the mountants, and benefits to rhodamine of changing from a Xenon to a mercury lamp, it was concluded that RB 200 conjugates could give brighter staining than FITC conjugates at similar dye:protein ratios.

(iv) DEAE-cellulose chromatography greatly improved the contrast of the staining, especially with RB 200 conjugates.

(v) After chromatography, RB 200 consistently gave better contrast than FITC.

(vi) The fluorescence of rhodamine-stained sections did not fade demonstrably when irradiated for several minutes with green light.

(vii) The fluorescence of FITC-stained sections faded rapidly when irradiated with ultra-violet (u.v.)+blue light. The fluorescence appeared to contain two components, one fading with first-order kinetics with a half-life of about a minute under the experimental conditions used and the other not fading at all.

(viii) Raising the pH improved the fluorescence of FITC-stained sections but did not affect rates of fading.

(ix) Narrow-band excitation of FITC-stained sections with blue light instead of u.v.+blue reduced the rate of fading and the fluorescence intensity by equal amounts, an effect presumably due merely to loss of excitation intensity.

     

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.