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Biomedical subjects

S Sammartano

Publications and source records attributed to S Sammartano.

9 recordsLinked to original sources

Serum calcium oxalate saturation in patients on maintenance haemodialysis for primary hyperoxaluria or oxalosis-unrelated renal diseases.

1. The serum oxalate concentration rises in chronic renal failure and it is only partially eliminated by regular dialysis treatment. However, the recent literature is not conclusive on whether progressive oxalate retention and secondary oxalosis should be expected in patients on regular dialysis treatment. 2. To further investigate this, we have estimated the state of saturation with respect to calcium oxalate monohydrate in plasma ultrafiltrates from 28 patients on maintenance haemodialysis and eight healthy control subjects, matched for sex and age. Five patients had type I primary hyperoxaluria and histologically proven oxalosis, whereas 23 had oxalosis-unrelated renal diseases. Dialysis efficiency was quantified as the KdTd/V of urea. Samples were obtained from each patient before, immediately after and 48 h after a dialysis session. Fasting samples were obtained from the control subjects. Oxalate was determined in both plasma ultrafiltrates and the whole dialysate by ion-exchange chromatography, after a non-delayed and [14C]oxalate-recovery-controlled procedure. The state of saturation with calcium oxalate monohydrate was estimated by means of a computer system which solved the interactions among 45 complex species. 3. The fasting plasma oxalate concentration (means +/- SD) in ultrafiltrates from healthy subjects was 3.8 +/- 1.5 (range 1.4-5.8) mumol/l, and the state of saturation with calcium oxalate monohydrate was 0.096 +/- 0.04.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Copper (II) complexes of aminoacids: gastric acid antisecretory activity in rats.

The effect of simple and mixed copper(II) complexes of L-tryptophan (trp) and L-phenylalanine (phe) on the gastric acid secretion was investigated in Shay rats. Graded doses (from 15 to 75 mg/kg) of [Cu(trp)2(H2O)], [Cu(phe)2(H2O)] and [Cu(trp)(phe)(H2O)], administered i.g., caused a progressive inhibition of gastric acid secretion. The antisecretory activity of the mixed complex, [Cu(trp)(phe)(H2O)], was significantly greater (ID50 = 33 +/- 3 mg/kg) than that of the simple complexes [Cu(trp)2(H2O)] (ID50 = 48 +/- 3 mg/kg) and [Cu(phe)2(H2O)] (ID50 = 43 +/- 3 mg/kg). At the experimental conditions of intragastric pH, the different biological activities were directly related to the percentage of neutral species present in solution as determined by means of potentiometric measurements (at 37 degrees, I = 0.15 mol dm-3 in NaClO4). A possible mechanism of action of the investigated compounds is discussed.

Amino Acids↗

[Effects of graded doses of copper complexes with L-aminoacids on gastric acid secretion in the rat].

Gastric acid responses to intragastric administration of graded doses (14-30-45 mg/Kg) of copper (II) complexes with aminoacids (two simple complexes, Cu-Trp2 and Cu-Phe2, and on mixed complex, Cu-Trp-Phe) were investigated in Shay rats. The results (% inhibition of H+ mEq/4h) shown that graded doses of copper complexes caused a progressive inhibition on gastric acid secretion, and that percentage inhibition values were, for all complexes, in linear correlation with employed doses. A possible mechanism by which copper complexes affect gastric acid secretion is discussed.

Animals↗

Binding of 1,2,4-benzenetricarboxylate by open chain polyammonium cations.

The interaction of some open chain polyammonium cations with 1,2,4-benzenetricarboxylate was studied potentiometrically, at 25 degrees C. For all the investigated systems, the species ALHr(r-3) (r = 1,2 ... n + 2; n = number of aminogroups; A = amine; L = carboxylate) are formed. The stability of these complexes depends on charges in the polyammonium cation and in the carboxylic ligand, and for the reaction HiAi+ + HjL(j - 3) = ALHi + j(i + j - 3) we found a mean free energy contribution for salt bridge -delta G0 = 6.5 +/- 0.3 kJ mol-1 n-1 (n = number of possible salt bridges). The results of this investigation are compared with those of similar systems. By considering also the tricarboxylic ligands citrate and 1,2,3-propanetricarboxylate, we found for their complexes with polyammonium cations a fairly close stability. Calculations performed including complexes formed with these two ligands give -delta G0 = 6.6 +/- 0.4 kJ mol-1 n-1.

Benzene Derivatives↗

[LithoRisk: A software for calculating and visualising nephrolithiasis risk profiles].

BACKGROUND: The pathogenesis of nephrolithiasis, based on the anomalies of the urinary environment, demands metabolic and physicochemical assessment for the medical management of patients. Standard metabolic protocols include the measurement of pertinent urine chemistry values and the calculation of the extent of saturation in stone-forming salts. However, patients are often given fragmentary and hard-to-consult reports and so this weakens the strength of the therapeutic recommendations. This paper introduces LithoRisk, a dedicated software which graphically represents risk profiles of stone formation, including the extent of saturation. METHODS: LithoRisk uses the results of 24-h urine chemistry values widely available in hospital laboratories, i.e., sodium, potassium, calcium, magnesium, ammonia, phosphate, sulphate, citrate, oxalate, chloride, pH and urine volume. Uric acid and cystine are optional. The relative supersaturation (beta), estimated according to our own ab initio calculation, is given in a scale whereby beta=1 is saturation, beta < 1 under - and beta > 1 oversaturation. LithoRisk is available as a CD-ROM and can be loaded on Windows 95/98/Millenium/XP. Colour or laser printers are suitable for printed records. RESULTS: LithoRisk is easily loaded on any PC by following video instructions. Once the loading of the program is completed a grey icon LithoRisk appears on the Desktop. The program can be opened by clicking twice on the icon. The patients data page first appears on the screen and is followed by the evaluation page for the input of variables. This generates the graph representing the diagnostic lithorisk profile, which is drawn as a line connecting different values, according to a specific scale and related to an arbitrary normal point. Normal values are shown as green lines, whereas abnormal ones are red. The beta values for calcium oxalate and phosphate, uric acid and cystine are instantaneously calculated and reported on the graph. CONCLUSIONS: LithoRisk produces a complete, unique and easy to understand report that includes all relevant parameters, it therefore expresses the overall risk of stone formation. It requires the results of chemistry tests done on the same 24-h urine collection, and carried out using suitable preservatives. If the tests for unusual parameters, i.e. sulphate and ammonia, are unavailable, one can use default values with minimal alterations on beta calculation. In spite of being arbitrary, the normal thresholds values are based on widely accepted literature data. The risk profile recognises the most relevant abnormalities and enables the establishment of individual targets aimed at reducing the propensity towards stone formation.

Humans↗

Production of cytokines at the operation site.

BACKGROUND AND AIM: Cytokines are part of a family of molecules involved in the initiation, control and termination of the events that occurs in wound healing process. Aim of this study was to evaluate the production of some cytokines [interleukin (IL)-6, IL-10, IL-1alpha, IL-1ra, interferon (IFN)-gamma] in the drainage wound fluid from patients undergoing incisional hernia repair. METHODS: Ten female patients with abdominal midline incisional hernia undergoing to surgical repair were included in this study. In all cases a closed suction drain was placed in the wound below the fascia and it was removed on the 4th postoperative day. Wound fluid was collected on the 1st, 2nd, 3rd and 4th day and its amount in each time was recorded. The production of IL-6, IL-10, IL-1alpha, IL-1ra and IFN-gamma were evaluated as quantity produced in 24 hour. RESULTS: In all patients the amount of drain fluid from surgical wound was highest on the 1st day after surgery, afterwards there is a significant reduction. The production of all cytokines evaluated was highest on the 1st day decreasing on the 2nd day except for IL-1alpha that not show any modification. The produciton of IL-1ra, IL-6, IL-1alpha and IL-10 was significantly reduced on the 3rd and 4th postoperative day in comparison with the respectively values recorded on the 1st day, whereas IFN-gamma levels were similar. CONCLUSIONS: The dosage of cytokines in the drain fluid led us to better evaluated the events that follow surgical wound and their analysis offers further information in the role of cytokines in healing process, with the goal to get supportive treatments to promote the best evolution.

Body Fluids↗