Search PubMed⌕ Search

Biomedical subjects

D Ciavarella

Publications and source records attributed to D Ciavarella.

At least 37 records · Page 2Linked to original sources
PubMed1993

Effect of prestorage white cell reduction on bacterial growth in platelet concentrates.

Platelet concentrates stored with and without autologous white cells were produced from units of whole blood that had been purposefully contaminated with bacteria immediately after phlebotomy. The blood was inoculated with one of five species of bacterium at either 10 or 50 colony-forming units per mL. The growth of the organisms was quantified throughout the conventional 5-day, 22 degrees C storage period of the platelet concentrates. One species, Klebsiella pneumoniae, failed to grow in any of the components. The remaining species, Staphylococcus epidermidis, S. aureus, Enterococcus faecalis, and Salmonella enteritidis, achieved log growth after 1 day of storage and reached a relative maximum concentration by Day 3. Although the concentration of bacteria immediately after inoculation was lower in the units reduced in white cells by filtration, no significant differences were observed thereafter. Data from this in vitro study support the concept that prestorage white cell reduction of platelet concentrates should not increase the likelihood of transfusion-induced septicemia.

Bacteria↗
PubMed1993

Transfusion therapy for severe anemia.

PURPOSE: We evaluated the safety and efficacy of a new transfusion regimen for children with severe anemia. PATIENTS AND METHODS: Twenty-two consecutive patients with severe anemia (hemoglobin < 5 g/dl) of gradual onset requiring transfusion of packed red blood cells (PRBC) were studied. The transfusion regimen consisted of continuous infusion of PRBC at the rate of 2 cc/kg/h until the desired volume was given. Throughout the transfusion, the patients were closely monitored for any clinical signs of heart failure. The rise in hematocrit per 1 cc of PRBC/kg transfused was computed for each patient. RESULTS: No patient developed any signs of cardiac failure or increase in the heart rate during or after the completion of transfusion. All patients had a decrease in the heart rate by the completion of transfusion. The mean decrease in the heart rate was 28% of the pretransfusion heart rate (range 12-44%). Excluding the four patients with sickle cell anemia, the remaining 18 patients had a mean increase in the hematocrit of 1.04% per 1 cc/kg of PRBC (range 0.85-1.28). CONCLUSION: We conclude that for children with severe anemia of gradual onset requiring transfusion therapy, continuous transfusion of PRBC at the rate of 2 cc/kg/h is a safe and effective regimen resulting in an increase in the hematocrit of approximately 1% for each 1 cc/kg of PRBC transfused in all patients, except patients with sickle cell anemia.

Acute Disease↗
PubMed1992

Peripheral blood stem cell mobilization by cytokines.

Hematopoietic stem cells circulate in the peripheral blood. These cells can be collected by apheresis techniques either in the unperturbed state, after mobilization following the administration of cytokines like G-CSF or GM-CSF, or during the phase of early blood count recovery following chemotherapy-induced myelosuppression. The number of cells collected following mobilization is greater than that obtained after apheresis in the unperturbed state. There are, however, qualitative differences between unperturbed and mobilized cells. Chemotherapy related mobilization can be potentially dangerous in that severe myelosuppression necessary to achieve mobilization can have serious consequences. There are no controlled studies that evaluate the relative merits of each method of collection. Regardless of the techniques employed peripheral blood stem cells can reliably accelerate hematologic recovery after potentially myeloblative therapy and provide an alternative to bone marrow support.

Blood Cell Count↗
PubMed1992

The use of protein A columns in the treatment of cancer and allied diseases.

The staphylococcal cell-wall protein known as protein A has been explored as a therapeutic modality in the treatment of cancer and allied diseases. Protein A binds the Fc fragment of IgG 1, 2 and 4, and preferentially binds to IgG incorporated into immune complexes. Early investigators focused on the immune-suppressive effects of immune complexes in cancer and, based on in vitro experiments, postulated that clearance of immune complexes in vivo would permit effective immune clearance of cancer cells. A large clinical trial of the perfusion of cancer patient plasma over protein A was subsequently undertaken. Results were generally disappointing, with no complete remissions and overall response rates of 22%. Response rates for Kaposi's sarcoma (39%) and breast adenocarcinoma (26%) were somewhat encouraging, and further clinical trials in these disorders are ongoing. More impressive have been the responses to protein A perfusion in immune thrombocytopenia and hemolytic-uremic syndrome. Using a protein A-silica device, Snyder et al. reported responses in 42% of immune thrombocytopenia patients, with mean increases in platelet count from 27 x 10(9)/l to 120 x 10(9)/l. On the basis of these results, the protein A-silica column was approved by the United States Food and Drug Administration for treatment of immune thrombocytopenia. Equally encouraging are reports of an overall 59% response rate in cancer chemotherapy-related hemolytic-uremic syndrome. Reported toxicities include fever, chills, hypotension, dyspnea and musculoskeletal pain. With rare exceptions, these reactions are easily treated and do not result in cessation of therapy. Unfortunately, the mechanism of action of plasma perfusion over protein A is very unclear.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoimmune Diseases↗
PubMed1992

Safety and efficacy of autologous blood donation before elective aortic valve operation.

Although the use of preoperative autologous blood donations for patients undergoing elective cardiac operations has increased dramatically in recent years, patients awaiting elective aortic valve replacement have traditionally been denied access to preoperative autologous blood collection programs. We report our experience with 79 patients, each of whom donated 1 to 3 units of autologous blood before an aortic valve operation. All patients had serious aortic valve disease as evidenced by symptoms and preoperative catheterization data. The patients collectively made 129 blood donations. One patient had a syncopal episode within 2 hours of donation and recovered without difficulty. Of the patients who gave autologous blood preoperatively, 68% avoided any homologous blood donor exposure during their subsequent hospitalization for aortic valve replacement. In contrast, in a group of 298 patients who did not give autologous blood preoperatively, only 31% avoided homologous blood exposure during aortic valve replacement (p < 0.0001). Our experience suggests that preoperative autologous blood donation by patients awaiting elective aortic valve replacement is both safe and effective. Patients with aortic valve disease should not be routinely excluded from preoperative blood services.

Adult↗
PubMed1992

Blood donation and transfusion practices: the 1990 American Association of Blood Banks Institutional Membership Questionnaire.

Responses to the 1990 American Association of Blood Banks (AABB) Institutional Membership Questionnaire were submitted by 2126 regional blood centers, hospital-based blood banks, and transfusion facilities. Data from 2117 of these facilities were considered to be valid. The questionnaire included information on blood donor demographics, number of units collected, and collection procedures; services performed; usage of blood components; and transfusion-transmitted diseases reported during 1989. Institutional members collected 7.4 million whole blood units, of which 90.8 percent were donated for allogeneic use, 6.0 percent were donated for autologous use, and 3.2 percent were donated for directed use. Approximately 630,546 allogeneic and directed-use blood donors were deferred, most often for low hemoglobin or hematocrit values. Approximately 225,205 full allogeneic and directed-donor units were discarded, primarily for elevated alanine aminotransferase levels or the presence of hepatitis B core antibody. The 14.3 million transfused components included 56.7 percent red cell-containing components, 27.4 percent platelets, 11 percent fresh-frozen plasma, and 4.8 percent cryoprecipitate. Institutional members reported 1397 cases of transfusion-associated hepatitis. In this group, 921 patients were tested for hepatitis B surface antigen after the transfusion; 339 (36.8%) were found to be hepatitis B surface antigen positive. The AABB Institutional Questionnaire results provide recent data on blood donor and transfusion-related activities that are vital to the evaluation of current transfusion medicine practices.

Acquired Immunodeficiency Syndrome↗
PubMed1992

The regulation of hematopoietic stem cell collection and storage: the New York State approach.

In December 1988, the New York State (NYS) regulatory code on bone marrow banking went into effect. The goals of the regulations were to codify a high standard of practice, to prohibit charlatanism in the practice or promotion of stem cell banking, and to promote legitimate research. The NYS approach modeled the stem cell regulatory language after that already established for blood banks and clinical laboratories. Also, the stem cell standards are an element of standards applicable to all tissue banks, developed as a result of a comprehensive transplant law enacted in NYS in 1990. The code itself, published as an addendum to this article, mandates that a qualified (by training and experience) medical director and medical advisory committee be appointed, and gives broad and complete responsibility for the services provided to that medical director. Explicit written policies and procedures regarding administrative, technical, safety, and quality issues are necessary, but regulatory micromanagement of the laboratory was avoided by limiting detailed procedural requirements. We believe that these regulations have contributed to the quality and safety of stem cell-related therapies in NYS.

Biological Specimen Banks↗
PubMed1992

Hemopoietic stem cell processing: comparison of progenitor cell recovery using the Cobe 2991 cell washer and the Haemonetics V50 apheresis system.

Using 24 bone marrow (BM) harvests intended for cryopreservation and transplantation, we compared the use of the Cobe 2991 cell washer (2991) and the Haemonetics V50 apheresis system (HV50) for automated BM processing. Our in vitro data indicate that while the mononuclear cell (MNC) concentration of the HV50 product was significantly greater than that of the 2991, the overall MNC recovery of the two products was equivalent. In addition, although the concentration of CFU-GM and BFU-E in the products was equivalent, recovery of these progenitors in the 2991 product was significantly greater than those of the HV50 product. There was no significant difference in either the final product concentration or the overall recovery of cells bearing the primitive myeloid antigens, CD33 or CD34, between the two methods. The HV50 product volume, the red cell and the granulocyte mass were significantly lower than those of the 2991. We conclude that the advantages gained through the use of each machine should be evaluated within the context of the specific intention for the graft. Future advances in the identification and understanding of the primitive stem cell will aid in attempts to evaluate the methods used to isolate these cells.

Adolescent↗