Accurate quantification of phosphorus intergranular segregation in iron by STEM-EDX

This study describes a method to quantify phosphorus grain boundary segregation by Energy Dispersive X-ray Spectroscopy in Scanning Transmission Electron Microscope (STEM-EDX). A "box-type method" is employed, removing the long-discussed problems of interaction volume and the beam broadening effect. The proposed methodology also introduces a novel way of subtracting the spectrum background to remove the influence of coherent Bremsstrahlung and spurious peaks. A Fe-P model alloy was used to compare the box method to the quantification results previously obtained by atom probe tomography on two high angle grain boundaries. The results are specifically reported in surface concentration (atom/nm²) to avoid additional hypotheses and allow the results between the two techniques to be directly compared. The measurements show that the box-type method can accurately measure phosphorus intergranular segregation in iron.

Body mass index and metabolic syndrome impact differently on major clinical events in renal transplant patients

OBJECTIVE

Kidney transplant recipients (KTRs) are bound to develop cardiovascular disease (CVD), and obesity represents a well-known risk factor for CVD. It has been reported that the metabolic syndrome (MetS) is a frequent finding in KTRs, and MetS could develop even if body mass index (BMI) is only mildly increased. We compared the impact of BMI and MetS on the development of major clinical events (MCEs) in a cohort of 107 KTRs during a follow-up of 63 ± 31 months.

PATIENTS AND METHODS

Clinical characteristics were recorded at the time of enrollment and patients were classified on the basis of MCEs development. In a Cox model, MCEs were the dependent variable while age, sex, history of CVD, glomerular filtration rate, length of dialysis pre-transplantation, BMI classes and diagnosis of MetS were independent variables. Patients were classified into 3 groups: normal (BMI < 25 kg/m2), overweight (BMI of 25 to 30 kg/m2) and obese (BMI > 30 kg/m2).

RESULTS

During follow-up, 55 MCEs were recorded: 16 patients died (15%), 19 (18%) had major cardiovascular events (CVEs), and 20 (19%) started dialysis due to graft failure. KTRs who had MCEs (n = 42) were older, had a lower renal function, longer dialysis vintage pre-transplantation, higher prevalence of history of CVD and higher BMI than those without MCEs. Cox regression analysis showed that length of dialysis pre-transplantation, renal function, previous CVD, and BMI classes (overweight and obesity) were related to MCEs.

CONCLUSIONS

BMI, but not MetS, predicted MCEs in KTRs as well as non-traditional CVD risk factors such as length of dialysis pre-transplantation and graft function. Thus, a simple evaluation during clinic visits could identify KTRs at high risk for MCEs.

Mammaglobin B (SCGB2A1) is a novel tumour antigen highly differentially expressed in all major histological types of ovarian cancer: implications for ovarian cancer immunotherapy

Background:

We studied the genetic fingerprints of ovarian cancer and validated the potential of Mammaglobin b (SCGB2A1), one of the top differentially expressed genes found in our analysis, as a novel ovarian tumour rejection antigen.

Methods:

We profiled 70 ovarian carcinomas including 24 serous (OSPC), 15 clear-cell (CC), 24 endometrioid (EAC) and 7 poorly differentiated tumours, and 14 normal human ovarian surface epithelial (HOSE) control cell lines using the Human HG-U133 Plus 2.0 chip (Affymetrix). Quantitative real-time PCR and immunohistochemistry staining techniques were used to validate microarray data at RNA and protein levels for SCGB2A1. Full-length human-recombinant SCGB2A1 was used to pulse monocyte-derived dendritic cells (DCs) to stimulate autologous SCGB2A1-specific cytotoxic T-lymphocyte (CTL) responses against chemo-naive and chemo-resistant autologous ovarian tumours.

Results:

Gene expression profiling identified SCGB2A1 as a top differentially expressed gene in all histological ovarian cancer types tested. The CD8+ CTL populations generated against SCGB2A1 were able to consistently induce lysis of autologous primary (chemo-naive) and metastatic/recurrent (chemo-resistant) target tumour cells expressing SCGB2A1, whereas autologous HLA-identical noncancerous cells were not lysed. Cytotoxicity against autologous tumour cells was significantly inhibited by anti-HLA-class I (W6/32) monoclonal antibody. Intracellular cytokine expression measured by flow cytometry showed a striking type 1 cytokine profile (i.e., high IFN-γ secretion) in SCGB2A1-specific CTLs.

Conclusion:

SCGB2A1 is a top differentially expressed gene in all major histological types of ovarian cancers and may represent a novel and attractive target for the immunotherapy of patients harbouring recurrent disease resistant to chemotherapy.

From primary progressive aphasia to corticobasal syndrome: two clinical and rCBF functional reports

We describe two cases, both presenting with a 2-year history of isolated language disorders, one compatible with logopenic variant and the other with non-fluent variant of primary progressive aphasia (PPA). Afterwards, each developed a corticobasal syndrome (CBS) with alien limb phenomenon and a multi-domain cognitive impairment. Regional cerebral perfusion (rCBF) study using 99mTc-ECD single photon emission computed tomography (SPECT) revealed hypoperfusion patterns consistent with these aphasia types and with the presence of limb apraxia. We report two cases of PPA variants associated with CBS and we suggest that SPECT rCBF correlates can be useful in making a differential diagnosis within the PPA spectrum.

Alpine skiing and anaerobic performance in solid organ transplant recipients

Limited information has been published about sporting activities in solid organ transplant recipients. The aim of this study was to assess "in the field" performance capacities of a group of transplant recipients involved in an alpine skiing competition. We studied 16 transplant recipients (13 men and 3 women) who had undergone transplantations (11 kidney, 4 liver, and 1 heart) at 89 +/- 68 months prior while participating in an alpine skiing race. The patients performed a countermovement jumping test to measure the explosive power of the lower limbs. In all patients blood lactate concentrations (La) were measured at the end of a giant slalom race. The maximum displacement of the center of mass during the jumping test was 22.4 +/- 9.3 cm; the time to complete the giant slalom was 75.5 +/- 16.5 seconds and La was 3.5 +/- 0.8 mmol/L. We observed significant linear relationships between race time and La (R(2) = 0.4733; P < .01) and between race time and performance in the jumping test (R(2) = 0.3655; P < .05). This study indicated that recovery of anaerobic and technical sporting activities is possible in organ transplant recipients. Muscular power and anaerobic performances among a selected group of solid organ transplant recipients were similar to those of the general untrained population.

Native kidney function after renal transplantation combined with other solid organs in preemptive patients

Kidney transplantations combined with other solid organs are progressively increasing in number. There are no guidelines regarding the nephrologic indications for combined transplantations, namely liver-kidney (LKT), or heart-kidney (HKT), in preemptive patients with chronic kidney failure who are not on regular dialysis therapy. The objective of this study was to assess the functional contribution of the native kidneys after preemptive kidney transplantation combined with other solid organs. From 2004, 9 patients (aged 50.3 +/- 8.5 years) with chronic kidney failure (creatinine 2.5 +/- 1.0 mg/dL) caused by polycystic kidney disease (n = 4), vascular nephropathy (n = 2), interstitial nephropathy (n = 1), glomerulonephritis (n = 1), or end-stage kidney disease (n = 1), underwent combined transplantations (8 LKT, 1 HKT). A scintigraphic functional study (Tc-99DMSA or Tc-99mMAG3), was performed at 4 +/- 3 months after transplantation to evaluate the functional contribution of both the native kidneys and the graft. All patients were given immunosuppressive drugs, including a calcineurin inhibitor (tacrolimus/or cyclosporine). At the time of scintigraphy, renal function in all patients was 1.3 +/- 0.3 mg/dL. The functional contribution of the transplanted kidneys was on average 77 +/- 18%. Only in 1 patient was the contribution of the graft <50%. At follow-up after 36 months, patient and kidney survivals were 100%. The study confirmed a high risk of loss of native kidney function in the presence of organic nephropathy. In light of our experience, a creatinine clearance <30 mL/min in an appropriate cutoff for a combined transplantation. Close clinical and instrumental assessment pretransplant is essential before proceeding with a combined transplant program to exclude functional forms and to optimize the use of organs.

[Low-toxicity immunosuppressive therapy in renal transplant]

INTRODUCTION

Renal allograft loss in the long term may be due to the death of a patient with a functioning graft or to chronic allograft nephropathy. One of the most important factors in the development of chronic allograft nephropathy is drug nephrotoxicity. The term nephrotoxicity comprises two distinct forms of renal injury: acute and chronic. Immunosuppressive drugs, and in particular calcineurin inhibitors, have a variety of side effects including nephrotoxicity. The nephrotoxicity associated with calcineurin inhibitors is well known; this association has also been described for the newer agents.

METHODS

We reviewed a large number of recent studies that attempted to reduce the toxicity of immunosuppressive regimens.

RESULTS

A number of low-toxicity protocols have been developed. Encouraging results have been obtained with regimens that reduce or eliminate nephrotoxicity-inducing calcineurin inhibitors and with regimens that reduce or eliminate steroids, which are responsible for many diseases that may lead to the death of the patient, even with a functioning graft.

CONCLUSION

All immunosuppressive drugs may be nephrotoxic, even if they act through different mechanisms. Combining different drugs at low dosage would therefore seem the best solution. It is not yet clear which regimens will be the most effective from the point of view of maximizing patient and graft survival, minimizing rejection, and minimizing adverse events.

Predictive Factors in Chronic Allograft Nephropathy

Chronic allograft nephropathy (CAN) is characterized by progressive renal dysfunction leading in many cases to graft loss. The pathogenesis of CAN involves both immune and nonimmune factors. Concerning immune factors, one of the most remarkable predictors of CAN is acute rejection, which is associated with a worse prognosis if there are multiple episodes or when late onset occurs. Delayed graft function is also a major risk factor for CAN because of a correlation between late restoration of renal function after transplantation and long-term decreased graft survival. High creatinine levels at 6 months and 1 year after transplantation, proteinuria, viral infections, and cardiovascular risk factors are additional significant parameters for the development of CAN. Recent findings suggest that a high renal segmental arterial resistance index measured by Doppler ultrasonography in intrarenal vessels is associated with poor allograft function. Moreover, the study of patient genetic profile represents a new approach to identify predictive factors for CAN.

[Therapy strategies in the prevention of chronic allograft nephropathy]

Chronic allograft nephropathy (CAN) is an anatomical and clinical alteration, characterized by proteinuria, hypertension and a progressive decline in kidney function, which begins at variable times (months, years) and can lead to the loss of the transplanted organ. CAN pathogenesis, which remains to be fully clarified, involves both immunological (early acute rejection, hyperimmunization, HLA-mismatches between donor and recipient, suboptimal immunosuppression, etc) and non-immunological factors (ischemia/reperfusion injury, reduced nephron mass, age differences between donor and recipient, dialysis time, hypertension, dislipidemia, proteinuria, etc). The possible prevention strategies for CAN consist of procedures aimed at the reduction of some potential risk factors: optimization of the conditions for organ explantation, diminution of ischemia/reperfusion injury, aggressive pharmacological treatment of acute rejection episodes, routine utilization of anti-hypertensive and hypolipidemic agents, and appropriate and rational immunosuppressive regimen. Moreover, some categories of immunosuppressive drugs, such as calcineurin inhibitors, can have a nephrotoxic effect, often regardless of therapeutic dosage. The introduction in clinical practice of novel immunosuppressive drugs with no nephrotoxicity, like mycophenolate mofetil and rapamycin, makes therapeutical strategies able to reduce the incidence of CAN feasible.

ELISA anti-HLA antibody screening identifies non-complement-fixing antibodies responsible for acute graft rejection. A case report

We report on a kidney transplant recipient experiencing an unexpected early acute vascular graft rejection. Retrospective analysis of patient serum samples, utilizing a new ELISA HLA screening technique, revealed that the rejection crisis and the subsequent graft loss were due to a pretransplant donor-specific pre-sensitization caused by a non-complement-fixing antibody of IgG2 class. The case illustrates the clinical significance of non-complement-fixing anti-HLA antibodies. In addition it is shown that ELISA methods are suitable for detecting potentially harmful donor pre-sensitization in waiting-list patients not detectable by standard lymphocytotoxicity techniques. Hence ELISA could be an alternative to flow cytometry for this purpose. It is concluded that screening and cross-matching techniques which detect non-complement-fixing anti-HLA antibodies could improve graft outcome, and should form part of the immunological monitoring of kidney transplant waiting-list patients.

Strategies in renal failure and the impact of lipids

The main points to note in terms of strategies in renal failure and the impact of lipids are: 1) Timing and typing of dyslipidemia; 2) Occurrence of dyslipidemia in the course of strategies (conservative, dialysis and transplantation); 3) How the strategies can handle the impact of lipids. Analysis of point 1 confirms what a complex profile uremic dyslipidemia presents, involving the type, class, composition and enzyme systems involved in lipid metabolism. In conservative and dialysis, type IV (triglycerides) predominates; in transplantation, type II (cholesterol). Examination of point 2 shows the non obligatory relationship between dyslipidemia and the various strategies of treatment. Lipid abnormalities, type IV or II, occur in 50-60% of patients. Uremic factors for dyslipidemia include: 1) enhanced hepatic stimulation or altered removal in conservative strategies; 2) the same causes plus "specific" promotors in dialysis (dialysis fluid, plasticizer leaching; bioincompatibility, etc.); 3) steroid therapy and other "accessories" in transplantation. A genetic predisposition is very likely present in all patients. Point 3, finally, analyzes the various "supplements" that each strategy requires to cope with the lipid impact. Generic rules (ranging from doing nothing, to diet, drugs, etc.) are of value in all strategies when dyslipidemia occurs. More specific rules include: a) Conservative strategies: appropriate dietetic optimization and modulation (protein-lipid-carbohydrate ratio in terms of calories); b) Dialysis: timing treatment and improving biocompatibility; c) Transplantation: reducing steroids as much as possible.

Strategies in Renal Failure and the Impact of Lipids

The main points to note in terms of strategies in renal failure and the impact of lipids are: 1) Timing and typing of dyslipidemia; 2) Occurrence of dyslipidemia in the course of strategies (conservative, dialysis and transplantation); 3) How the strategies can handle the impact of lipids. Analysis of point 1 confirms what a complex profile uremic dyslipidemia presents, involving the type, class, composition and enzyme systems involved in lipid metabolism. In conservative and dialysis, type IV (triglycerides) predominates; in transplantation, type II (cholesterol). Examination of point 2 shows the non obligatory relationship between dyslipidemia and the various strategies of treatment. Lipid abnormalities, type IV or II, occur in 50-60% of patients. Uremic factors for dyslipidemia include: 1) enhanced hepatic stimulation or altered removal in conservative strategies; 2) the same causes plus “specific” promotors in dialysis (dialysis fluid, plasticizer leaching; bioincompat-ibility, etc.); 3) steroid therapy and other “accessories” in transplantation. A genetic predisposition is very likely present in all patients. Point 3, finally, analyzes the various “supplements” that each strategy requires to cope with the lipid impact. Generic rules (ranging from doing nothing, to diet, drugs, etc.) are of value in all strategies when dyslipidemia occurs. More specific rules include: a) Conservative strategies: appropriate dietetic optimization and modulation (protein-lipid-carbohydrate ratio in terms of calories); b) Dialysis: timing treatment and improving biocompatibility; c) Transplantation: reducing steroids as much as possible.

Flow cytometry evaluation of urinary sediment in renal transplantation

The value of exfoliative urinary cytology for the diagnosis of different pathological conditions in renal transplantation is widely recognized. The method, however, has not yet gained full acceptance, mainly because identification of the different cells is not always possible by means of standard staining techniques. In view of its characteristics, flow cytometry (FC) seems to represent a consistently reliable, rapid and innovative approach for differentialing the various cells present in the urinary sediment and assessing their number. This study gives the examination result of 223 urinary specimens from 127 transplanted patients selected according to pathology. Sediment cells, collected from fresh urine samples, were washed, treated with a lysing solution, resuspended in saline solution and directly analysed in a FACSCAN cytometer. Morphological evaluation showed: a small number of cells in patients with stable renal function; a larger number of cells, with predominance of lymphocytes, during acute rejection episodes; an absolute predominance of neutrophils during bacterial infection; large-sized cellular debris in cases of post-transplant tubular necrosis; and small cell debris in cases of cyclosporine cytotoxicity. Lymphocyte surface-marker evaluation made it possible to differentiate lymphocyte populations observed during acute rejection episodes (cytotoxic T-cell, CD8 and HLA class II and NK cells) from those detected during bacterial infection (T-cell CD4 positive). These results suggest that urinary FC may be a reliable diagnostic tool in clinical renal transplantation.

Hormonal changes in hemodialysis

When chronic renal failure becomes advanced, the serum or tissue levels and/or the functions of most hormones are altered because of several interplaying mechanisms involving synthesis, transport, accumulation of inhibitors, abnormality of target organ responsiveness, and impaired renal clearance. As regular dialysis treatment is performed, most of these uremic hormone abnormalities are not reversed, and some of them may even get worse. The main endocrine derangements can be grouped as sexual hormone dysfunction, thyroid abnormalities, growth retardation, hormone-related disorders of metabolism, derangements of pressor substances, gastrointestinal peptide abnormalities, renal osteodystrophy, and anemia. The endocrine abnormalities play a major role as for the clinical and metabolic rehabilitation of dialysis patients.

Normalization of renal function and blood pressure after dissolution with intra-arterial fibrinolytics of a massive renal artery embolism to a solitary functioning kidney

The intra-arterial administration of fibrinolytics in a massive embolism to the renal artery of a solitary functioning kidney determined quick normalization of the severe renal failure and hypertension.

[In-hospital and long-term prognosis in acute myocardial infarction. Comparative longitudinal study of 2 patient groups]

The in-hospital mortality, the causes of death, the actuarial survival curves were compared in two subsequent groups of patients admitted to our CCU for acute myocardial infarction: the first (group A) includes 791 pts, admitted from september '67 to december '72, the second (group B) includes 542 pts admitted from january '78 to june '80. The in-hospital mortality was significantly reduced in group B (A: 186/791, 23.5%; B: 72/542, 13,3%, p less than 0.01). This could be due to a reduction of the number of deaths for cardiogenic shock (A: 71/791, 9%; B: 30/542, 5.6%; p less than 0.01) and to reduction in the mortality rate for pulmonary oedema (from 6% to 1.5%, p less than 0.01), although the frequency of pulmonary oedema was the same during the two periods (A: 205 pts, 26%; B/156 pts 29%). We did not observe any significant difference in the long-term prognosis (54 months: A 79.3%, B 71.5%). The actuarial survival curves overlapped after the 1st semester after discharge. The most frequent cause of death during follow-up was a new myocardial infarction. None in the group A and only 3% in the group B were referred to the surgeon for coronary artery bypass grafting. We conclude that, in spite of a significant reduction of the in-hospital mortality, possibly related to the evolution in diagnosis and management of the disease, the long-term survival was not improved in a non-surgically treated population with myocardial infarction.

Effect of nitroglycerin on ST potentials in the post-acute phase of myocardial infarction

Thoracic electromaps were recorded before and after sublingual nitroglycerin (NG) in 26 subjects 15 and 30 days after acute myocardial infarction (MI), in order to evaluate the effect of the drug on injury potentials. Ten patients with documented left ventricular aneurysm were also studied 5 to 46 months after acute MI. Fifteen min after NG there was a significant decrease, compared with basal values, of ST segment elevations, blood pressure and rate-pressure product on both the 15th and 30th days. The degree of ST potentials reduction was not strictly related to the decrease of myocardial oxygen consumption, as indicated by the rate-pressure product. The response to NG on the 15th day did not predict accurately the evolution of injury potentials. In fact there was no significant correlation between percentages reduction of ST after NG on the 15th day and amplitudes of ST segment elevations present on the 30th day. In the patients with ventricular aneurysm, ST potential decrease and hemodynamic changes after NG were similar to those observed in the other groups studied. Our data suggest that it is not possible to differentiate between ST segment elevations associated with a dyssynergic area and those merely due to ischemic injury on the basis of NG sensitivity, and that ST segment elevations in the acute and subacute phase and long after MI have, at least in part, a similar electrophysiological significance.