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Biomedical subjects

A Candido

Publications and source records attributed to A Candido.

At least 19 recordsLinked to original sources

Phosphatidylserine exposure in platelet concentrates during the storage period: differences between the platelets collected with different cell separators.

BACKGROUND AND OBJECTIVES: Platelet alterations occur during the production and storage of platelet concentrates, the so called "storage lesion". We studied the platelet alterations during the storage period in apheresis concentrates, employing flow cytometry for phosphatidylserine (PS) detection on platelets during the five days of storage. MATERIAL AND METHODS: Twenty-seven single donor platelet concentrates harvested with the Cobe Trima, Baxter Amicus, or Haemonetics MCS+ were analyzed for PS exposure by flow cytometry on the day of production (day 1) and on days 3 and 5 of storage. Furthermore PS expression was analyzed in platelet donors' blood samples withdrawn before plateletpheresis. RESULTS: PS expression on platelets gave the following median values: in blood donors before apheresis it was 1.12% (0.13-1.78) in platelets concentrates on the first day (2 h after apheresis) 2.06% (0.66-15.2), the third day 6.57% (1.98-51.13) and the fifth day 23.04% (3.86-80.23). All differences between median values of PS expression in blood samples before apheresis, and platelets concentrates on days 1, 3 and 5 of storage, are statistically significant. The expression of PS in platelet concentrates was analyzed in relation to the blood cell separator used for the collection procedure and showed the following results: on day 1 the median values of PS in platelet concentrates collected with the three different blood cell separators, Trima, Cobe and MCS, did not show statistically significant differences. On day 3, the platelets concentrates collected with the Trima and with the MCS showed differences that were statistically significant. Those were respectively 10.59% (4.56-51.13) and 3.53% (1.98-12.61), p = 0.005. The PS expression in platelet concentrates collected with the Trima and MCS showed differences that are also statistically significant on day 5 at respectively 32.4% (9.61-80.23) and 8.57% (3.86-48.42), p = 0.005. CONCLUSIONS: PS exposure in platelet concentrates on days 3 and 5 rise to levels that could compromise the quality of the platelet units. Improvements in standardized platelet quality controls, and in platelet collection systems are required to reduce the storage lesions in platelets concentrates.

Adult↗

Taste aversion learning and aging: a comparison with the effect of dorsal hippocampal lesions in rats.

The relationship between hippocampal function and aging was explored in Wistar rats using taste aversion learning by comparing the performance of adult dorsal hippocampal lesioned and fifteen-month-old intact rats with that of adult intact rats. In experiment 1 the conditioned blocking phenomenon was absent in the hippocampal and the aging rats. Unlike the adult intact rats, the hippocampal and aging rats were not impaired in acquiring a learned aversion to a cider vinegar solution (3 %) presented as a serial compound with a previously conditioned saccharin solution (0.1 %). In experiment 2 both the hippocampal and the aging rats developed reduced aversions to a saline solution (0.5 %) followed by an i.p. injection of lithium chloride (0.15 M; 2 % b.w.) if the taste solution was previously preexposed without consequences. This latent inhibition effect was similar to that seen in intact adult rats. In both experiments, the aging rats exhibited enhanced conventional learned taste aversions. It is concluded that aging is not a unitary process but induces both hippocampal dependent and hippocampal independent complex changes in the functioning of the neural circuits, implementing taste aversion learning.

Acetic Acid↗

Stem cell collection using the dideco excel continuous flow blood cell separator: parameters for optimal stem cell collection timing.

This study evaluates stem cell collection procedures performed with the Dideco Excel blood cell separator, with particular attention given to yields and separator collection efficiencies. Patients' blood precounts and yield parameters related to the harvest capacity of the collection system were investigated. Fifty-five collection procedures were analyzed in 32 patients suffering from hematological malignancies and solid tumors and mobilized with chemotherapy plus G-CSF. The median blood volume processed in each procedure was 15.8 liters (12-19.750), with a blood flow rate of 70 ml/min. Patients had the following median blood precount value: NC 7.81x10(9)/L, CD34+ cells 49.08x10(3)/ml. Leukapheresis procedures gave the following yields: NC 14.95x10(9), MNC 10.83x10(9), CD34+ cells 4.37x10(6); yields/kg, NC 0.21x10(9)kg, MNC 0. 15x10(9)/kg CD34+ cells 4.26x10(6)/kg. Procedures show the following collection efficiencies: NC 10.79%, MNC 29.06%, CD34+ 42.33%, PLT 26.5%. The RBC (red blood cell) contamination of the product was (median value) 20.9 ml for each procedure, and for platelets 1.76x10(11) per procedure. The CD34+ cell precounts strongly correlated with the CD34+ yields/kg (r=0.82. p=0.000). Furthermore the NC and MNC precounts correlated with the CD34+ yields/kg but only the MNC precount correlation is notable (r=0.57, p=0.000). The logistic regression analysis shows that CD34+ (p=0.008) but not NC (po=0.14), MNC (p=0.09), or PLT (p=0.53) precounts significantly influenced the collection of a sufficient dose of CD34+ cells for transplantation (> or =2.5x10(6)/kg). Eleven of the thirty-two patients have been transplanted till now, and all had a prompt and lasting trilineage engraftment NC >1x10(9)/L on day 12 (10-17). Our data show that the collection system analyzed in this report is able to collect large amounts of progenitor cells, harvesting >2.5x10(6)/kg CD34+ cells with a single procedure in 68.8% of patients and assuring complete recovery after stem cell transplantation.

Adolescent↗

Serum transferrin receptors in rheumatoid arthritis.

OBJECTIVE: Serum transferrin receptors (sTfR) were determined in patients affected by rheumatoid arthritis (RA) to verify a possible relationship with the degree of anaemia and with the severity of the inflammatory disease. METHODS: sTfR, IL1-b, TNF-a and common parameters of iron metabolism were studied in 72 patients with active RA. Anaemia (Hb < 12 g/dl) was present in 51 patients. Twenty normal healthy subjects and 40 iron-deficient anaemic patients without chronic inflammatory, infective or malignant diseases were studied as controls. RESULTS: In patients with RA sTfR levels were significantly higher than in the normal group but lower than in iron-deficient anaemic patients and correlated positively with ESR and IL1-b and negatively with Hb. Anaemic patients with RA were divided into two groups. Group A (56%) showed a possible iron deficiency (TSI < 16 and ferritin < 50 ng/ml); group B did not show iron deficiency (TSI > 16 and ferritin > 50 ng/ml). No significant difference in sTfR was observed in the two groups. CONCLUSION: sTfR appear to be elevated and related to the degree of anaemia and to the inflammatory process in RA. Reduced sTfR levels in patients with RA compared with patients with iron-deficiency anaemia may indicate a reduced erythropoietic activity in RA.

Adolescent↗

Tamoxifen-induced immune-mediated platelet destruction. A case report.

Drug-induced immunologic thrombocytopenia, a fairly common disorder, is characterized by drug-dependent antiplatelet antibodies that destroy circulating platelets in the presence of the provoking drug or its metabolites. The development of reliable methods for the detection of platelet-bound immunoglobulins causing in vivo platelet destruction, such as the use of monoclonal antibodies tagged with fluorescein and flow cytofluorimetric analysis, has ushered in a new era to differentiate between immune and non-immune thrombocytopenias. A severe thrombocytopenia developed in an elderly female patient treated with tamoxifen, a non-steroidal anti-estrogen drug, after surgery for breast cancer. A tamoxifen-dependent platelet antibody was detected in the patient's serum and linked on the platelet membranes. This antibody reacted only in the presence of the offending drug and showed platelet specificity. Withdrawal of drug restored platelet count to normal levels.

Aged↗

Effect of diazepam on successive negative contrast in one-way avoidance learning.

The effect of administration of diazepam on successive negative contrast in one-way avoidance learning was examined in rats. Contrast was induced by shifting rats from a large reward, 30 s spent in the safe compartment, to a small reward, 1 s spent in the safe compartment. IP administration of 2 mg/kg diazepam eliminated this negative contrast. Moreover, this effect is dose dependent, with doses of 2 and 2.5 mg/kg, but not 0.5 mg/kg, effective in reliably reducing contrast. These results suggest the existence of similar or common underlying mechanisms in both aversive and appetitive contrast effects; they are discussed in light of the current theories of frustrative nonreward and as a mean of studying the behavioral and biological mechanisms of anxiety.

Animals↗

Comparison of the side effects of therapeutic cytapheresis and those of other types of hemapheresis.

The side effects of a series of 2418 hemapheresis procedures performed in a total of 570 subjects (patients and donors) are described. Patients with various diseases were subjected to plasmapheresis (926 procedures in 181 patients) or cytapheresis (305 procedures in 89 patients). One hundred twelve plasmapheresis procedures and 1075 of cytaphereses were also performed in 300 blood donors. A total of 225 complications involving 107 patients (39.6%) occurred during 196 (15.9%) therapeutic procedures. Among the blood donors only 45 complications, involving 35 patients (11.6%) occurred during 45 procedures (4.2%). The complications seen with therapeutic plasmaphereses were circulatory disturbances (38% of all those observed), citrate reactions (27%), technical problems (20%), allergic reactions (9%) and miscellaneous complications (6%). Therapeutic cytaphereses were complicated by citrate reactions (44%), technical problems (25%), circulatory disturbances (14%), allergic reactions (11%) and miscellaneous complications (6%). Complications in the blood donor group included circulatory disturbances (51%), technical problems (36%) and various other problems (13%). No infectious complications or deaths were observed. The probability that adverse reactions will occur depends on the condition of the patient, the frequency of the sessions and the volume of fluid exchanged. Evaluation of the main risk factors, use of less intensive protocols and interruption of the session at the first sign of disturbances will help improve patient tolerance of these procedures.

Blood Donors↗

Oxidative stress of red blood cells stored for transfusion use.

Some oxidative indexes and the level of reduced glutathione have been determined on red blood cells stored for transfusion use. Conjugated dienes show a concentration which increases until around the third week of storage and then comes back to lower values. On the contrary malonyldialdeyde shows a decreasing level until the third week and then rises rapidly to very high values. Reduced glutathione rises until about the end of the second week and then falls to very low values. Free haemoglobin continuously rises through the whole period of storage; from these data it is evident that a storage time not exceeding 21 days gives the best transfusion results.

Alkenes↗

Myelodysplastic syndromes: analysis of 51 cases. Therapy with low doses of arabinosyl cytosine of leukaemic transformation.

Clinical, haematological, cytogenetic features and therapeutic problems of 51 patients with MDS were examined. Patients were distributed in 5 FAB subgroups: RA 21, SA 7, RAEB 8, RAEB-t 9 and MMCL 6 patients. Leukaemic transformation occurred in 3 RA, 3 RAEB, 7 RAEB-t and 3 MMCL patients. No SA patient suffered from leukaemic transformation. Cytogenetic alterations occurred in 13 of 29 examined patients; 5q- was the most common abnormality. We did not find any relation between chromosomal anomalies and FAB subgroups. Leukaemic transformation, however, was more frequent in patients with cytogenetic aberrations. In some cases it was not easy to determine the precise diagnostic allocation according to FAB subgroups; it is possible, however, to subdivide MDS prognosis into 2 classes. The more satisfactory therapy of leukaemic transformation is often due to low doses of Ara-C; this therapy allowed a better survival and sometimes to obtain CR which in a M6 ANLL patient continued for 24 months.

Aged↗

Sequential therapy with lithium in chemotherapy-induced vomiting.

Having noticed psychotic traits in some patients showing incoercible vomiting due to antineoplastic drugs we have thought of establishing a therapy with lithium in the days preceding the therapeutic cycle in order to reduce the emetic events. The effectiveness of lithium carbonate (600 mg/mq p.o./day for one week) in the prevention or reduction of vomiting induced by antiblastic therapy has been checked in comparison with metoclopramide and domperidone in 40 patients. In the group pretreated with lithium, 80% of the cases showed favorable results. In the control groups, on the contrary, the efficacy of the antiemetic therapy has shown to be of lesser importance (55%). The undesirable side-effects of lithium appear to be irrelevant. We therefore think that pretreatment with lithium may become, in selected cases not affected by traditional antiemetics, of great importance in the control of emetic symptomatology.

Adolescent↗

Acquired neutrophil myeloperoxidase deficiency: an indicator of subclinical activation of blood coagulation?

Using an automated cytochemical analyzer used for routine differential counts, we have been able to demonstrate acquired myeloperoxidase deficiency in 102 patients at our institution. Clinical and laboratory data on these patients showed a high incidence of diabetes mellitus (25.5%) and thrombotic diseases (24.5%), as well as a strikingly constant hyperfibrinogenemia (mean = 635 mg/100 ml; range = 360-1015 mg/100 ml). In 4 additional acute leukemia patients in complete remission, a close time correlation was noted between acquired MPO deficiency, diffuse intravascular coagulation and relapse. These findings indicate the importance of the relationships between neutrophil granulocytes and blood coagulation, and suggest that similar changes in neutrophil MPO activity may represent an early morphological indicator of subclinical activation of blood coagulation.

Adolescent↗

Indicative morphological myelodysplastic alterations of bone marrow in overt AIDS.

In HIV infection, numerous alterations of the hematopoietic system, with frequent cytopenias in peripheral blood and dysplasia of the bone marrow, have been observed. In order to assess the incidence of the myelodysplastic anomalies, 69 bone marrow aspirate smears from 47 patients with group IV HIV infection, as classified by CDC, have been studied. Various degrees of myelodysplastic alterations were found in all cases; however, dysgranulopoiesis was more frequent and more accentuated than other kinds of dyshematopoiesis. Intense vacuolization, especially in the granuloblastic series, was very frequent. It is felt that a bone marrow configuration that is highly indicative of overt AIDS can be sketched. The human immune deficiency virus may be either directly or indirectly responsible for myelodysplastic alterations.

Acquired Immunodeficiency Syndrome↗