Search PubMed⌕ Search

Biomedical subjects

C Robert Valeri

Publications and source records attributed to C Robert Valeri.

At least 19 recordsLinked to original sources
PubMed2006

Salvaging of liquid-preserved O-positive and O-negative red blood cells by rejuvenation and freezing.

BACKGROUND: The RBC inventory is subject to seasonal highs and lows. When the inventory is high, units may be lost due to outdating and when the inventory is low, elective surgical procedures may have to be postponed until sufficient blood is available. This study was done to determine if universal donor O-positive and O-negative RBC subjected to various methods of transportation could subsequently be rejuvenated and frozen to be used for inventory control with satisfactory results. MATERIALS AND METHODS: Units of blood were collected at two different military facilities and processed as whole blood (WB) or packed RBC. The liquid stored WB or RBC units were subjected to transportation, with or without air dropping, as part of a military exercise. The units were kept at 4 degrees C with wet ice during transportation to the NBRL for evaluation. The quality of the liquid preserved RBC was evaluated before rejuvenation and freezing and after the freeze-thaw-wash procedure. Following frozen storage at -80 degrees C, the RBC were thawed and deglycerolized using the Haemonetics 115 cell washer. In addition to measurements of freeze-thaw and freeze-thaw-wash recovery, other in vitro assessments of RBC quality were made. RESULTS: The results demonstrate acceptable quality for RBC subjected to transportation, with or without air dropping, following rejuvenation and freezing. CONCLUSION: We consider it a prudent practice for liquid preserved O-negative and O-positive RBC collected at various blood collection sites to be sent to a specific facility where the universal donor RBC can be rejuvenated and frozen as a stockpile for inventory control.

Blood Banks↗
PubMed2006

In vitro testing of platelets using the thromboelastogram, platelet function analyzer, and the clot signature analyzer to predict the bleeding time.

BACKGROUND: Platelet aggregation, thromboxane A2 production and platelet annexin V binding are in vitro tests used to assess platelet function. This study was done to evaluate the clot signature analyzer (CSA), platelet function analyzer (PFA), and thromboelastogram (TE) as in vitro tests to predict the template bleeding time (BT). STUDY DESIGN AND METHODS: Twelve normal volunteers were studied before and after removal of 2 units of RBC. Seven females were reinfused their RBC and 5 males were not. Samples were collected prior to and at 24, 48, and 72 h and 7 days after the RBC removal whether or not reinfusion of RBC was performed for measurement of TE, CSA, PFA and template BT. RESULTS: BT increased significantly following the removal of 2 units of RBC and BT decreased significantly after the reinfusion of the 2 units of RBC in the 7 female volunteers. BT decreased during the 7-day period in the 5 male volunteers not reinfused their RBC. No significant correlations were observed between BT and platelet hemostatic time (PHT) and clotting time (CT) in the CSA and between the bleeding time and the closure time (CT) in the platelet function analyzer (PFA). Significant correlations were observed between BT and K time, the MA, and the angle recorded in the thromboelastogram. CONCLUSION: In this study in vitro testing using the clot signature analyzer, platelet function analyzer and the thromboelastogram could not be used to predict the template bleeding time.

Annexin A5↗
PubMed2006

A comparison of the acute hemodynamic and delayed effects of 50% exchange transfusion with two different cross-linked hemoglobin based oxygen carrying solutions and Pentastarch.

BACKGROUND: Hemoglobin based oxygen carrying solutions (HBOC) have been designed to combine the beneficial effects of colloidal solutions with oxygen carrying capacity. Clinical trials in humans using HBOCs have had variable results. METHODS: We used a rodent 50% exchange model to compare Hemolink and Hemopure HBOC to autologous blood and Pentastarch solution. We monitored hemodynamic parameters, hemoglobin clearance, weight gain and hematocrit over a five-day period. RESULTS: Acute hemodynamic effects between the two HBOCs were similar with mild vasoconstriction. Cardiac output, systemic vascular resistance and renal function were similar to that seen with blood. HBOC's were associated with hemoglobinuria with a half-life in the circulation of 13.8 hrs for Hemolink and 19.2 hrs for Hemopure. Animals resuscitated with HBOCs exhibited delayed weight gain. CONCLUSION: Hemodynamic effects in rodents exchange-transfused with blood, Hemolink, or Hemopure were similar. The delayed weight gain observed with the HBOCs must be investigated.

Animals↗
PubMed2006

Effects of the resuscitation fluid and the hemoglobin based oxygen carrier (HBOC) excipient on the toxicity of the HBOC: Ringer's D,L-lactate, Ringer's L-lactate, and Ringer's ketone solutions.

Hemoglobin based oxygen carriers (HBOC) are resuspended in "excipients" consisting of Ringer's D,L-lactate containing antioxidants to prevent methemoglobin formation during storage. Investigators have reported cardiac arrhythmias following infusion of Ringer's D,L-lactate solution. Studies have shown that D-lactate stimulates human granulocytes to generate oxygen free radicals and L-lactate inhibits glycolysis. Patients receiving HBOC in Ringer's D,L-lactate excipient are also resuscitated or hemodiluted with Ringer's lactate solution. Oxygen-free radicals generated by Ringer's D,L-lactate and HBOC may oxidize nitric oxide in endothelial cells, causing the vasoconstrictor effects reported following HBOC infusion, and activate NF-kappab and the apoptotic cascade. The combination of Ringer's D,L-lactate and HBOC in Ringer's D,L-lactate excipient may be responsible for the severe adverse events observed in clinical studies of HBOC.Veech has recommended replacing the 27 mM of lactate in Ringer's with 27 mM D-betahydroxybutyrate (BHB). BHB reduces the generation of oxygen free radicals by mitochondria and human granulocytes.

Animals↗
PubMed2006

Hepatic and pulmonary apoptosis after hemorrhagic shock in swine can be reduced through modifications of conventional Ringer's solution.

BACKGROUND: Cytotoxic properties of racemic (D-,L-isomers) lactated Ringer's solution detected in vitro and in small animal experiments, have not been confirmed in large animal models. Our hypothesis was that in a clinically relevant large animal model of hemorrhage, resuscitation with racemic lactated Ringer's solution would induce cellular apoptosis, which can be attenuated by elimination of d-lactate. METHODS: Yorkshire swine (n = 49, weight 40-58 kg) were subjected to uncontrolled (iliac arterial and venous injuries) and controlled hemorrhage, totaling 40% of estimated blood volume. They were randomized (n = 7/group) to control groups, which consisted of (1) no hemorrhage (NH), (2) no resuscitation (NR), or resuscitation groups, which consisted of (3) 0.9% saline (NS), (4) racemic lactated Ringer's (DL-LR), (5) L-isomer lactated Ringer's (L-LR), (6) Ketone Ringer's (KR), (7) 6% hetastarch in 0.9% saline (Hespan). KR was identical to LR except for equimolar substitution of lactate with beta-hydroxybutyrate. Resuscitation was performed in three phases, simulating (1) prehospital, (2) operative, (3) postoperative/recovery periods. Arterial blood gasses, circulating cytokines (TNF-alpha, IL-1, -6, -10), and markers of organ injury were serially measured. Metabolic activity of brain, and liver, was measured with microdialysis. Four hours postinjury, organs were harvested for Western blotting, ELISA, TUNEL assay, and immunohistochemistry. RESULTS: All resuscitation strategies restored blood pressure, but clearance of lactic acidosis was impeded following DL-LR resuscitation. Metabolic activity decreased during shock and improved with resuscitation, without any significant inter-group differences. Levels of cytokines in circulation were similar, but tissue levels of TNF in liver and lung increased six- and threefolds (p < 0.05) in NR group. In liver, all resuscitation strategies significantly decreased TNF levels compared with the NR group, but in the lung resuscitation with lactated Ringer (DL and L isomers) failed to decrease tissue TNF levels. DL-LR resuscitation also increased apoptosis (p < 0.05) in liver and lung, which was not seen after resuscitation with other solutions. CONCLUSIONS: In this large animal model of hemorrhagic shock, resuscitation with conventional (racemic) LR solution increased apoptotic cell death in liver and lung. This effect can be prevented by simple elimination of D-lactate from the Ringer's solution.

Animals↗
PubMed2006

Release of platelet-derived growth factors and proliferation of fibroblasts in the releasates from platelets stored in the liquid state at 22 degrees C after stimulation with agonists.

BACKGROUND: Fresh platelet (PLT)-rich plasma (PRP) treated with thrombin plus calcium chloride (CaCl(2)) is used to prepare a PLT gel to promote hemostasis and wound healing in a variety of surgical procedures. The effects of various agonists on stimulating the release of growth factors from liquid-preserved PLTs and the effects of the PLT releasate on the growth of fibroblasts in tissue culture were investigated. STUDY DESIGN AND METHODS: Plateletpheresis PLTs stored at 22 degrees C as high-yield PLTs for 3 to 6 days or outdated PLTs for 9 days were treated with agonists to assess release of platelet-derived growth factor (PDGF) AA, PDGF AB, PDGF BB, transforming growth factor-beta1 (TGF-beta1), and osteocalcin and the proliferation of fibroblasts treated with the PLT releasates in tissue culture. RESULTS: All treatments except for CaCl(2) alone and zeolite-CaCl(2) produced significant increases in PDGF AA compared to PRP. Thrombin-CaCl(2) produced significant increases in PDGF BB. Treatment by all the agonists produced similar increases in PDGF AB. TGF-beta1 and osteocalcin levels after treatment were similar to those in PRP. PRP releasate before and after stimulation with different agonists increased proliferation of fibroblasts in tissue culture. CONCLUSION: High-yield and outdated liquid-preserved PLTs released PDGF AA, AB, and BB but not TGF-beta1 or osteocalcin. The releasate from untreated PRP stimulated the proliferation of fibroblasts in tissue culture similar to the releasates from PRP treated with the different agonists. Further studies are needed to assess whether or not high-yield and outdated PLTs may be useful in wound healing.

Animals↗
PubMed2006

Limitations of the hematocrit level to assess the need for red blood cell transfusion in hypovolemic anemic patients.

BACKGROUND: The transfusion trigger that physicians use to determine whether a patient requires a red blood cell (RBC) transfusion is the peripheral venous hematocrit (Hct) value. Although this measurement is an indicator of the concentration of RBCs in the blood, it does not reveal the RBC volume, plasma volume, or total blood volume, nor does it give any indication of whether the patient is hypovolemic, normovolemic, or hypervolemic. STUDY DESIGN AND METHODS: Two patient populations were studied: 41 consecutive patients subjected to elective vascular surgery and 20 consecutive patients subjected to cardiopulmonary bypass surgery. The RBC volume was measured with (51)Cr- or (99m)Tc-labeled autologous fresh RBCs, and the plasma volume and total blood volume were estimated from the measured RBC volume and the total body Hct level. Measurements made 1 to 2 and 24 hours after surgery were compared to the preoperative values for these two groups of patients. RESULTS: During the 24-hour postoperative period, the RBC, plasma, and total blood volumes were reduced compared to the preoperative volumes. These patients were hypovolemic and anemic, and their Hct values during the 24-hour postoperative period were increased by a mean of 4 to 5 volume-percent compared to values that would be expected if they were normvolemic and anemic. CONCLUSIONS: The Hct values in hypovolemic anemic patients are elevated because the plasma volume does not increase to achieve the normovolemic anemic state.

Aged↗
PubMed2006

The survival and function of baboon red blood cells, platelets, and plasma proteins: a review of the experience from 1972 to 2002 at the Naval Blood Research Laboratory, Boston, Massachusetts.

The studies reported in this monograph were performed between 1972 and 2002 when it was possible to study healthy male and female baboons. A colony of baboons was maintained for 30 years without any adverse events observed in these baboons in the numerous studies that were performed. These protocols were reviewed and approved by the institutional animal care and use committees (IACUC) at the sites where the studies were performed and by the veterinarian services of the U.S. Navy's Bureau of Medicine and Surgery, the Office of Naval Research, and the Department of Defense. The physiology of red blood cells (RBCs), platelets (PLTs), and plasma proteins in the baboon was investigated together with the viability and function of preserved RBCs, PLTs, and plasma proteins. These studies in the baboon could not have been performed in normal volunteers and patients. The data obtained have provided critical information to explain the clinical observations reported in normal volunteers and patients after transfusion of fresh and preserved blood products. These studies were supported by the U.S. Navy's Bureau of Medicine and Surgery and the Office of Naval Research. In addition, the support of the late Congressman J. Joseph Moakley from Massachusetts is acknowledged because without his support many of these studies could not have been performed. The authors acknowledge the contributions of the numerous research collaborators identified in the 52 peer-reviewed publications that cite other funding agencies that supported the research that is reported, the editorial assistance of Ms Cynthia Ann Valeri, and the assistance of Ms Deborah Tattersall who prepared the figures and tables reported in this publication.

Animals↗
PubMed2005

Hepatic apoptosis after hemorrhagic shock in rats can be reduced through modifications of conventional Ringer's solution.

BACKGROUND: Resuscitation with racemic lactated Ringer's solution induces cellular apoptosis. This study was conducted to determine if the elimination of D-lactate isomer would attenuate apoptosis in the liver, and to investigate the possible mechanisms. STUDY DESIGN: Sprague Dawley rats (n=30, 5 per group) were subjected to modified volume-controlled hemorrhage and randomized to the following groups: no hemorrhage (sham); no resuscitation (NR); resuscitation with racemic lactated Ringer's (DL-LR); L-isomer LR (L-LR); ketone (beta-hydroxybuturate) Ringer's (KR); or pyruvate Ringer's (PR). Animals were sacrificed 2 hours later and expressions of proapoptotic proteins (BAD), antiapoptotic (bcl-2) proteins, and poly-ADP ribose polymerase (PARP) cleavage in liver were analyzed by Western blotting. Contribution of the phosphatidylinositol 3-kinase/serine/threonine kinase (PI3k/Akt) pathway was assessed by measuring total and phosphorylated PI3K, Akt, BAD, and endothelial nitric oxide synthase (eNOS) proteins. The terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) assay was used to detect the apoptotic cells. Liver ATP levels were measured using a luciferase reaction assay. RESULTS: Hemorrhage significantly decreased the hepatic ATP level and resuscitation improved it, but it returned to normal only in the L-isomer lactated Ringer's and ketone Ringer's groups. Expression of proapoptotic proteins was significantly lower in the pyruvate Ringer's and ketone Ringer's groups; L-isomer lactated Ringer's and pyruvate Ringer's resuscitation significantly increased bcl-2 expression. Poly-ADP ribose polymerase fragmentation and total number of apoptotic cells were significantly increased in the racemic lactated Ringer's group. There was no significant induction of Akt activity or changes in phosphorylated BAD, Akt, or eNOS levels. CONCLUSIONS: Resuscitation with racemic lactated Ringer's induces hepatic apoptosis, which is decreased if the D-isomer of lactate is eliminated. Apoptosis is reduced even more when lactate is substituted with beta-hydroxybutyrate or pyruvate. The beneficial effects are not through improvements in the energy status or activation of the PI3K/Akt pathway.

Adenosine Diphosphate↗
PubMed2005

Rapamycin ameliorates proteinuria-associated tubulointerstitial inflammation and fibrosis in experimental membranous nephropathy.

Proteinuria is a risk factor for progression of chronic renal failure. A model of proteinuria-associated tubulointerstitial injury was developed and was used to examine the therapeutic effect of rapamycin. Two studies were performed. In study A, proteinuric rats were given sheep anti-Fx1A to induce experimental membranous nephropathy; control rats received normal sheep serum. Four weeks later, groups were subdivided and underwent laparotomy alone (two kidneys), nephrectomy alone (one kidney), or nephrectomy with polectomy (0.6 kidney). Renal function and morphology were evaluated 4 wk later. Whereas control rats never developed proteinuria, anti-Fx1A induced severe proteinuria. Proteinuria was unaffected by renal mass reduction. Proteinuric rats developed tubulointerstitial disease that was most severe in rats with 0.6 kidneys. Renal function (GFR) was reduced by loss of renal mass and was reduced further in proteinuric rats with 0.6 kidneys. In study B, the effect of rapamycin on the expression of candidate proinflammatory and profibrotic genes and the progression of proteinuria-associated renal disease were examined. All rats received an injection of anti-Fx1A and were nephrectomized and then divided into groups to receive rapamycin or vehicle. Gene expression, renal morphology, and GFR were evaluated after 4, 8, and 12 wk. Rapamycin reduced expression of the proinflammatory and profibrotic genes (monocyte chemotactic protein-1, vascular endothelial growth factor, PDGF, TGF-beta(1), and type 1 collagen). Tubulointerstitial inflammation and progression of interstitial fibrosis that were present in vehicle-treated rats were ameliorated by rapamycin. Rapamycin also completely inhibited compensatory renal hypertrophy. In summary, rapamycin ameliorates the tubulointerstitial disease associated with chronic proteinuria and loss of renal mass.

Animals↗
PubMed2005

Circulation and distribution of 111-In-oxine-labeled autologous baboon platelet aggregates and buffy coat.

BACKGROUND: Although it is known that RBC concentrates may contain buffy coat and platelet concentrates may contain platelet aggregates, the circulation and distribution of these materials in the blood products have never been reported. STUDY DESIGN AND METHODS: Baboon platelets were labeled with 111-In-oxine, aggregated with ADP and autotransfused without a filter. Baboon buffy coat was stored at 4 degrees C, labeled with 111-In-oxine and autotransfused without a filter. The circulation of the radiolabeled platelets and buffy coat was measured and the distribution of the buffy coat and platelet aggregates was measured by external scanning of the baboon using a gamma camera. The effects of the infusion of aggregated platelets, buffy coat, and gelatin on the plasma fibronectin level also were evaluated. RESULTS: The 111-In-oxine labeled platelet aggregates were initially sequestered in the lungs and released into the peripheral blood during the next 3h, during which time the cell associated radioactivity increased by about 25%. Following the autotransfusion of 111-In-oxine labeled buffy coat, the 111-In-oxine radioactivity over the lungs increased, but decreased during the 60-min post-transfusion period as the radioactivity over the liver increased. Cell-associated radioactivity increased by about 10% over the 3-h post-transfusion period. Fibronectin levels decreased by 3% following the autotransfusion of platelet aggregates, by 10% after the autotransfusion of buffy coat and by 50% after the infusion of gelatin. CONCLUSIONS: 111-In-oxine radioactivity in the platelet aggregates and buffy coat was initially sequestered in the lungs, and 10-25% of the 111-In-oxine cell-associated radioactivity was released into the circulation during the 24-h post-transfusion period.

Animals↗
PubMed2005

Comparison of radioisotope methods and a non-radioisotope method to measure platelet survival in the baboon.

BACKGROUND: The in vivo survival of autologous fresh and preserved platelets can be measured using 51-Cr and 111-In-oxine radioisotope procedures and by a non-radioisotope procedure using biotin-X-N-hydroxysuccinimide (NHS) with detection in the flow cytometer using fluorescent streptavidin. This study was done to assess the specificity of the radioisotopes 51-Cr and 111-In-oxine and non-radioactive biotin-X-NHS to label platelets to measure their in vivo recovery and lifespan. STUDY DESIGN AND METHODS: In the study reported here, aliquots of autologous platelets from the same baboon were labeled with 51-Cr, 111-In oxine and biotin-X-NHS to measure platelet survival. Both cell-associated and platelet-associated 51-Cr and 111-In oxine radioactivity were assessed to measure the in vivo recovery and lifespan of platelets. Blood volume was measured using the 125I albumin plasma volume and the total body hematocrit. RESULTS: In vivo recovery values measured during the 1-3h post-infusion period and during the 8 day post-infusion period showed significant differences between the 51-Cr-labeled and the 111-In-oxine labeled platelets. In the 51-Cr-labeled platelets, the cell-associated radioactivity was about 50% higher than the platelet-associated radioactivity. In the 111-In-oxine labeled platelets, the cell-associated radioactivity was about 10% higher than the platelet-associated radioactivity. Similar in vivo recovery values were observed in the biotin-X-NHS labeled platelets and the 111-In-oxine labeled platelets assessed from the cell-associated 111-In-radioactivity. CONCLUSION: The radioisotope 51-Cr and 111-In are non-specific labels for platelets, whereas biotin-X-NHS is a specific label for platelets identified in the flow cytometer with fluorescent streptavidin. The in vivo recovery values of autologous baboon platelets were similar when assessed from the cell-associated 111-In-oxine radioactivity and biotin-X-NHS labeled platelets.

Animals↗
PubMed2005

Automation of the glycerolization of red blood cells with the high-separation bowl in the Haemonetics ACP 215 instrument.

BACKGROUND: The FDA has approved a closed-system red blood cell (RBC) glycerolization procedure with the ACP 215 (Haemonetics), which requires a centrifuge to prepare RBCs before and after glycerolization. In the study reported here, the Haemonetics high-separation bowl was evaluated in an attempt to automate these two concentration steps. STUDY DESIGN AND METHODS: Ten units of nonleukoreduced citrate phosphate dextrose (CPD)-anticoagulated whole blood were stored at 4 degrees C for 2 to 6 days before glycerolization and freezing as nonrejuvenated RBCs. Twenty-five units of nonleukoreduced CPD whole blood were stored at 4 degrees C for 2 to 8 days and then biochemically treated with a solution containing pyruvate, inosine, phosphate, and adenine (PIPA) before glycerolization and freezing as indated-rejuvenated RBC. Twenty units of leukoreduced CPD and AS-1 RBCs were stored at 4 degrees C for a mean of 48 days and treated with PIPA solution before glycerolization and freezing as outdated-rejuvenated RBCs. The glycerolized RBCs were frozen for at least 2 weeks at -80 degrees C, deglycerolized in the Haemonetics ACP 215 with the 325-mL bowl, and stored in AS-3 at 4 degrees C for 21 days. RESULTS: It took approximately 50 minutes to glycerolize the nonrejuvenated and rejuvenated RBCs. After freezing, deglycerolization, and postwash storage at 4 degrees C in AS-3 for 2 weeks, the quality was similar to that of RBCs processed by the current FDA-approved method. CONCLUSION: Processing time and need for technical expertise were significantly reduced with the completely automated functionally closed glycerolization procedure with the high-separation bowl in the Haemonetics ACP 215 instrument.

2,3-Diphosphoglycerate↗