Sequential convective therapies (SCT): a prospective study on feasibility, safety, adequacy and tolerance of on-line hemofiltration and hemodiafiltration in sequence

Sequential dialysis techniques (i.e pure ultrafiltration followed by dialysis) have been used in the past, due to their capability to remove large volumes of fluids without inducing hemodynamic instability. The disadvantages of inadequate efficiency and lack of technology lead to the decline of such methods. Hemofiltration (HF) and hemodiafiltration (HDF) are recently being utilized in a greater proportion thanks to on-line fluid preparation systems. Each process (HF and HDF) has its own benefits in the removal of small, medium and high-molecular weight substances and in hemodynamic stability. Sequential convective therapies (SCT) such as hemofiltration-hemodiafiltration in sequence (HF-HDF) may combine the benefits and eliminate the disadvantages of each method and should be studied in order to explore their potential application in modern dialysis. Furthermore they can be easily applied nowadays, due to the development of new sophisticated dialysis machines. In order to evaluate the feasibility, safety, efficiency and tolerance of different SCT methods we studied 3 schedules: SCT1: 1h pre-dilution HF followed by 3h of post-dilution HDF (in the HF mode we lost 25% of the total fluid that had to be removed). SCT2: 1h pre-dilution HF followed by 3h of post-dilution HDF (in the HF mode we lost 50% of the total fluid that had to be removed). SCT3: 2h pre-dilution HF followed by 2h of post-dilution HDF (in the HF mode we lost 50% of the total fluid that had to be removed). We studied 6 chronic hemodialysis patients using the same machine (AK200 ULTRA), with on-line fluid preparation system and the same type of dialyzer (Polyflux 210). SCT schedules were compared to on-line HF, on-line HDF and high flux dialysis performed with the same dialyzers. The treatments resulted safe, easy, feasible and well tolerated with an improved hemodynamic response to high volume convective therapies. Adequacy of treatment was satisfactory in all SCT schedules while middle molecular weight solute clearance and removal resulted higher in treatments with higher convective component. SCT might represent an interesting option for the future especially in patients with hemodynamic instability and requirements for interventions during treatment.     

Phenotypic and phoniatric findings in mosaic cri du chat syndrome

We report on mosaic 46,XY/46,XY,del(5)(p15) cri du chat syndrome. The clinical findings are compared with those compiled from a literature survey. A phoniatric evaluation was performed and compared with that of a cri du chat patient without mosaicism previously observed by the authors.     

Effects of substantia nigra stimulation on hypothalamic rage reaction in cats

The effects of substantia nigra (SN) (pars compacta) stimulation on the rage reaction elicited by ventromedial hypothalamic nucleus (VMH) were investigated in the cat. The studied parameters of the rage reaction were: the current and the frequency threshold for the appearance of the hissing and the hissing latency. A facilitatory effect induced by the SN on the hypothalamic rage reaction was observed in the form of a decrease in the hypothalamic stimulus threshold for the hissing appearance and a decrease in the hissing latency. Moreover, when the VMH was stimulated with parameters below the threshold for the hissing display, simultaneous nigral activation determined its appearance. The excitatory influence exerted by the SN on the affective component of the aggressive behavior is discussed.     

Phase I-II study of gamma interferon and 5-fluorouracil for patients with metastatic renal cell carcinoma

We have completed a phase I/II trial to evaluate the toxicity and efficacy of the combination of gamma interferon and 5-fluorouracil in metastatic renal cell carcinoma. Gamma interferon was administered at a weekly dose of 100 micrograms. 5-fluorouracil was given as a 5 day continuous infusion days 1-5 of each 21 day cycle. In the phase I portion of the trial, the gamma interferon dose was held constant, while the 5-fluorouracil was escalated from 500 to 800 mg/m2/day. Serum neopterin and beta 2 microglobulin were measured prior to and 48 hours after each dose of gamma interferon for the first six weeks of treatment. Dose limiting toxicity was not encountered in the phase I part of the trial; therefore the phase II study was initiated at the 800 mg/m2/day dose of 5-fluorouracil. No responses were seen among 34 patients treated on the phase II trial. Forty-six percent of patients experienced disease stabilization and the remainder progressed through treatment. In the phase I trial, increments in neopterin and beta 2 microglobulin levels differed significantly between patients treated with lower and higher doses of 5-fluorouracil. We conclude that the addition of 5-fluorouracil to gamma interferon does not appear to enhance the cytokines clinical activity. Incremental increases in macrophage activation markers with escalating 5-fluorouracil doses suggests a role for 5-fluorouracil beyond its usual proposed cytotoxic activity and warrants further investigation into potential immunologic effects of this drug.     

OCT imaging of choroidal neovascularisation and its role in the determination of patients'' eligibility for surgery

AIM: To evaluate the optical coherence tomographic characteristics of choroidal neovascularisation (CNV) in age related macular degeneration (AMD) and in idiopathic and inflammatory CNV. The use of this technique in the selection of patients for surgery is discussed. METHODS: Ocular coherence tomography (OCT), fluorescein, and indocyanine green angiography were performed in 23 patients affected by AMD complicated by well defined CNV and in 10 patients affected by inflammatory or idiopathic CNV. The neovascular membrane was surgically removed in five age related CNVs, two inflammatory choroidopathies, and two idiopathic CNVs. RESULTS: In inflammatory and idiopathic CNV, the OCT displayed a neovascularisation on the retinal pigment epithelium (RPE). In three cases the CNV was excised with an improvement of visual acuity equal to or greater than two Snellen lines; in a fourth case, the visual acuity after surgery was unchanged. In the cases of AMD the OCT fell into three different patterns: (A) CNV above the RPE (five cases); (B) focal, irregular thickening of the retinal pigment epithelial band (12 cases); (C) CNV above and below the RPE (six cases). The five pattern A CNV patients underwent the surgical excision of the neovascularisation. In four cases the visual acuity improved by two or more Snellen lines; in the fifth case the visual acuity remained unchanged. CONCLUSIONS: The authors suggest that the surgical removal of early age related CNV could be performed in those cases where the OCT shows a neovascular membrane on the RPE, as in idiopathic and inflammatory CNVs.     

Diabetic maculopathy induced by vitreo-macular traction: evaluation by optical coherence tomography (OCT)

Aim: To evaluate the role and efficacy of optical coherence tomography (OCT) in the evaluation of diabetic maculopathy induced by vitreo-retinal traction. Methods: 12 patients affected by diabetic maculopathy induced by vitreo-retinal traction were examined using biomicroscopy with a three-mirror contact lens, fluorescein angiography (FA) and OCT scanning in order to identify the presence of a vitreomacular traction. Results: OCT revealed two patterns of maculopathy which were characterised by a thickening of the superior profile of the OCT tomogram or by the disappearance and inversion of the physiologic foveal depression respectively. Conclusions: OCT may be useful in the characterisation and monitoring of diabetic maculopathy induced by vitreo-retinal traction. This revised version was published online in July 2006 with corrections to the Cover Date.     

Attempts to culturing triatominae in the laboratory using "in vitro" feeding]

In order to simplify breeding of triatominae in the laboratory, for performing xenodiagnosis and other biologic studies, we tried to feed the insects "in vitro" with citrated or defibrinated blood from commercially abated chicken. Two types of efficacy observations were carried out with Triatoma infestans: a) analysis of the chaining of successive nymphal stages, viability of satisfactory matching, fertile oviposition and adequate reproduction; b) assessment of viability and infectivity of Trypanosoma cruzi in the insects. As a conclusion, it became evident that, despite operational easiness, the objectives were not achieved, since the classical procedure used as the control, was always superior.     

Reproducibility validation study comparing analog and digital imaging technologies for the measurement of intima-media thickness

BACKGROUND AND PURPOSE: New advances in B-mode imaging technologies have led to improved quality in the detection of minute changes in the surface of intima-media thickness (IMT) and plaques. The new digital systems, with increased numbers of imaging channels, multiple frequency probes, and increased microprocessing speeds, now generate images comparable to those of the analog predecessors. Can these digital systems have reproducibility comparable to that of a pure analog system? We compared the Biosound 2000II (analog) system with the Esaote AU4 (digital) system. METHODS: Twenty-two subjects were chosen who had varying degrees of IMT on the far wall of the common carotid artery. Common carotid IMT was determined twice: the first time with the analog system and the second time with the digital system. With each system, replicate scans were made within 2 weeks. RESULTS: The intramethod agreement was high with the analog system, with a bias between readings of -0.010+/-0.033 mm, mean absolute difference of 0.027+/-0.020 mm, repeatability coefficient of 0.067, and correlation coefficient of 0.97. The digital system provided the highest reproducibility with a bias between readings of 0.002+/-0.016 mm, mean absolute difference of 0.012+/-0.011 mm, repeatability coefficient of 0.033, and correlation coefficient of 0. 99. When the analog and digital systems were compared, the bias between readings was -0.011+/-0.024 mm with good agreement between the 2 systems; the repeatability coefficient was 0.047, with all points within +/-2 SDs of the mean difference. The mean absolute difference between the 2 measurements was 0.018+/-0.015 mm with a correlation coefficient of 0.98. CONCLUSIONS: The digital system for IMT evaluation compares well with the more widely used analog system and provides a reliable technology for common carotid IMT measurement that can be applied to clinical trials.