bluuebunny/crossref_metadata_2025_split huggingface dataset:
Appearance, location, course, and morphology of the mandibular incisive canal: an assessment on spiral CT scan.
Authors: Jacobs R , Mraiwa N , vanSteenberghe D , Gijbels F , Quirynen M 
Published: September 2002

OBJECTIVES To assess the appearance, location, and course of the incisive canal as compared to other anatomical landmarks on spiral CT of the mandible. METHODS Study material included 230 spiral CT scans taken for preoperative planning of implant placement in the posterior mandible. All scanning was performed using a standard exposure and patient positioning protocol. Axial, panoramic, and reformatted cross-sectional images were carefully examined. Visibility of the incisive canal and other anatomical landmarks was scored using a four-point rating scale. The vertical and buccolingual diameter of the outer contour as well the diameter of the inner contour of the incisive canal were measured using a digital sliding caliper. RESULTS An incisive canal was identified in 93% of the cases, with good visibility in 22% of the cases. Mean (s.d.) vertical diameter, buccolingual diameter, and inner diameter of the incisive canal were 4.7 (1.1), 3.7 (0.7), and 1.1 (0.3) mm respectively. The mandibular canal, mental foramen, lingual foramen, and anterior looping appeared in 98, 100, 82 and 7% of the images respectively. CONCLUSIONS A well-defined incisive canal could be detected in the majority of spiral CT scans. Its radiographic detection remained lower than for the mandibular canal or mental foramen, but higher than for the visibility of the lingual foramen. Visualisation of the incisive canal and the occasional presence of an anterior looping, demonstrates the potential value of cross-sectional imaging of the anterior mandible for presurgical planning purposes.
Effect of Urate on Nitric Oxide Microcirculatory Response in the Rat Tail to Body Heating
Authors: Widanski B. , Richardson D. , Bruckner G. 
Published: September 2002

Objective: The objective of this study was to determine if nitric oxide (NO)‐mediated cutaneous vasodilation depends on urate concentrations.Methods: Capillary blood cell velocities (BCV) in the tail capillary vessels of anesthetized, heat‐stressed Sprague‐Dawley rats were measured by the videomicroscopy method, and the femoral mean arterial pressure (MAP) was recorded on a Grass polygraph. The effects of urate or urate and NO production on the above parameters were determined by using specific inhibitors of these compounds, for example, allopurinol (All) or All or N‐nitro‐L‐arginine (NNA), respectively. Urate concentrations were determined by an enzymatic, colorimetric method, and total nitrite levels were measured fluorometrically.Results: During heat stress, All or All and NNA significantly decreased plasma urate or urate and total nitrite concentrations, respectively, and the response of vascular conductance (estimated as a ratio of BCV to MAP). Urate administration, after All and NNA pretreatment, restored plasma urate and total nitrite concentrations and increased BCV/MAP.Conclusions: Urate at physiological concentration helps to maintain vascular conductance of cutaneous capillaries in the rat tail during body heating. The effect of urate on vascular conductance may be mediated by NO.
Blood Flow and Red Blood Cell Deformation in Nonuniform Capillaries: Effects of the Endothelial Surface Layer
Authors: SECOMB T.W. , HSU R. , PRIES A.R. 
Published: September 2002

ABSTRACTObjective: A theoretical model is used to examine the mechanics of red blood cell (RBC) motion in nonuniform capillaries. The model includes effects of the endothelial surface layer (ESL), which is a layer of macromolecules adjacent to the endothelium and which impedes plasma flow.Methods: The motion of an RBC traversing a capillary with diameter varying sinusoidally between 5.4 µm and 7.4 µm is simulated numerically. The ESL is assumed to be 0.7‐µm wide and deformable. Axisymmetric RBC shapes are assumed. Lubrication theory is used to analyze the motion of plasma around the RBC and through the ESL.Results: In a nonuniform capillary with no ESL, moving RBCs undergo large transient deformations and predicted flow resistance is substantially higher than in a uniform capillary with the same mean diameter. The presence of a deformable ESL reduces the transient fluid shear stresses and deformations experienced by RBCs traversing a nonuniform capillary. With an ESL, the increase in flow resistance resulting from nonuniformity is less than twofold versus three‐ to fourfold with no ESL in vessel geometries with the same ESL‐free luminal region.Conclusions: The presence of the ESL reduces the impact of capillary irregularity on flow resistance and may protect RBCs traversing irregular capillaries from damage due to large, rapidly fluctuating external stresses.
The Physiology of Endothelial Xanthine Oxidase: From Urate Catabolism to Reperfusion Injury to Inflammatory Signal Transduction
Authors: MENESHIAN AVEDIS , BULKLEY GREGORY B. 
Published: September 2002

ABSTRACTXanthine oxidoreductase (XOR) is a ubiquitous metalloflavoprotein that appears in two interconvertible yet functionally distinct forms: xanthine dehydrogenase (XD), which is constitutively expressed in vivo; and xanthine oxidase (XO), which is generated by the posttranslational modification of XD, either through the reversible, incremental thiol oxidation of sulfhydryl residues on XD or the irreversible proteolytic cleavage of a segment of XD, which occurs at low oxygen tension and in the presence of several proinflammatory mediators. Functionally, both XD and XO catalyze the oxidation of purines to urate. However, whereas XD requires NAD+ as an electron acceptor for these redox reactions, thereby generating the stable product NADH, XO is unable to use NAD+ as an electron acceptor, requiring instead the reduction of molecular oxygen for this purine oxidation and generating the highly reactive superoxide free radical. Nearly 100 years of study has documented the physiologic role of XD in urate catabolism. However, the rapid, posttranslational conversion of XD to the oxidantgenerating form XO provides a possible physiologic mechanism for rapid, posttranslational, oxidant‐mediated signaling. XO‐generated reactive oxygen species (ROS) have been implicated in various clinicopathologic entities, including ischemia/reperfusion injury and multisystem organ failure. More recently, the concept of physiologic signal transduction mediated by ROS has been proposed, and the possibility of XD to XO conversion, with subsequent ROS generation, serving as the trigger of the microvascular inflammatory response in vivo has been hypothesized. This review presents the evidence and basis for this hypothesis.
Pathophysiology of Preeclampsia: Linking Placental Ischemia/Hypoxia with Microvascular Dysfunction
Authors: GRANGER JOEY P. , ALEXANDER BARBARA T. , LLINAS MARIA T. , BENNETT WILLIAM A. , KHALIL RAOUF A. 
Published: September 2002

ABSTRACTStudies during the past decade have provided a better understanding of the potential mechanisms responsible for the pathogenesis of preeclampsia. The initiating event in preeclampsia has been postulated to be reduced uteroplacental perfusion as a result of abnormal cytotrophoblast invasion of spiral arterioles. Placental ischemia/hypoxia is thought to lead to widespread activation/dysfunction of the maternal vascular endothelium which results in enhanced formation of endothelin, thromboxane, and superoxide, increased vascular sensitivity to angiotensin II, and decreased formation of vasodilators such as nitric oxide and prostacyclin. These endothelial abnormalities, in turn, cause hypertension by impairing renal function and increasing total peripheral resistance. While recent studies support a role for cytokines and other factors such as lipid peroxides and reactive oxygen intermediates as potential mediators of endothelial dysfunction, finding the link between placental ischemia/hypoxia and maternal endothelial and vascular abnormalities remains an important area of investigation. The quantitative importance of the various endothelial and humoral factors in mediating the vasoconstriction and elevation in arterial pressure during preeclampsia has also not been completely elucidated.
Mortality and morbidity in patients with very low postoperative Hb levels who decline blood transfusion
Authors: Carson Jeffrey L. , Noveck Helaine , Berlin Jesse A. , Gould Steven A. 
Published: September 2002

BACKGROUND: Guidelines for allogeneic transfusion emphasize minimizing use to avoid transmission of serious illness. However, there is little information on the risks associated from withholding transfusion. STUDY DESIGN AND METHODS: A retrospective cohort study of patients who declined RBC transfusions for religious reasons was performed. This analysis was restricted to consecutive patients ≥18 years old, who underwent surgery in the operating room from 1981 to 1994 and had a postoperative Hb count of 8 g per dL or less. The primary outcome was defined as any in‐hospital death occurring within 30 days of the surgery. Secondary outcome was 30‐day mortality or in‐hospital 30‐day morbidity. Morbidity was defined as myocardial infarction, arrhythmia, congestive heart failure, or infection. RESULTS: Of 2083 eligible patients, 300 had postoperative Hb counts of 8 g per dL or less. The study population was predominantly female (70.3%) with a mean age of 57 years (SD, ± 17.7). In patients with a postoperative Hb level of 7.1 to 8.0, 0 died (upper 95% CI, 3.7%), and 9.4 percent (95% CI, 4.4‐17.0%) had a morbid event. In patients with a postoperative Hb level of 4.1 to 5.0, 34.4 percent (95% CI, 18.6‐53.2%) died and 57.7 percent (95% CI, 36.9‐76.6%) had a morbid event or died. After adjusting for age, cardiovascular disease, and Acute Physiology and Chronic Health Evaluation II score, the odds of death in patients with a postoperative Hb level of ≤8 g per dL increased 2.5 times (95% CI, 1.9‐3.2) for each gram decrease in Hb level. CONCLUSIONS: The risk of death was low in patients with postoperative Hb levels of 7.1 to 8.0 g per dL, although morbidity occurred in 9.4 percent. As postoperative blood counts fall the risk of mortality and/or morbidity rises and becomes extremely high below 5 to 6 g per dL.
Clinical specificity and sensitivity of a blood screening assay for detection of HIV‐1 and HCV RNA
Authors: Vargo Janet , Smith Katie , Knott Caroline , Wang Songbai , Fang Chyang , McDonough Sherrol , Giachetti Cristina , Caglioti Sally , Gammon Richard , Gilbert Denise , Jackson J. Brooks , Richards William , Stramer Susan , Mimms Larry 
Published: September 2002

BACKGROUND: An HIV‐1 and HCV NAT blood screening assay (Procleix HIV‐1/HCV, Gen‐Probe, Inc.) simultaneously detecting HIV‐1 and HCV RNA) has been implemented. Donor plasma samples reactive in the Procleix HIV‐1/HCV assay are tested with the HIV‐1 and HCV discriminatory assays to resolve whether HIV‐1 RNA, HCV RNA, or both are present. STUDY DESIGN AND METHODS: To determine the specificity of the Procleix HIV‐1/HCV assay, data were analyzed for samples from 192,288 donations, tested in 16‐member pools. To determine sensitivity, data were analyzed for 2014 commercial samples known to contain HIV‐1, HCV, or both, as well as 10 HIV‐1 and 10 HCV commercial seroconversion panels. RESULTS: The specificity of the Procleix HIV‐1/HCV assay was 99.7 percent. The HIV‐1 and HCV discriminatory assays showed similar specificity. The sensitivity of the Procleix HIV‐1/ HCV assay was 99.9, 99.6, and 100 percent, respectively, for samples containing HIV‐1, HCV, or both. The Procleix discriminatory assays were comparably sensitive. The Procleix discriminatory assays detected all tested samples of known HIV‐1 subtype or HCV genotype. Procleix HIV‐1/HCV testing of seroconversion panels showed that the median times to a positive reaction for HIV‐1 and HCV were reduced by 3 and 25 days, respectively, compared to serologic tests. CONCLUSION: These studies support the use of the Procleix HIV‐1/HCV assay for routine blood donor screening.
Declining value of preoperative autologous donation
Authors: Goldman Mindy , Savard Renée , Long Anne , Gélinas Stéphanie , Germain Marc 
Published: September 2002

BACKGROUND: Preoperative autologous blood donation (PABD) has been shown to decrease allogeneic blood transfusion requirements in major elective surgery. Changes in transfusion practice motivated an examination of blood use from 1993 to 2000 of patients participating in the Héma‐Québec PABD program. STUDY DESIGN AND METHODS: Blood donation and transfusion, type of surgery, and demographic characteristics were prospectively entered into a computer database for patients participating in the Héma‐Québec PABD program. RESULTS: Autologous donations represented from 0.8 to 2 percent of total blood collections and have declined by 26 percent after peaking in 1995. The mean number of units collected per patient declined, as did the number of units transfused per patient and the utilization rate. For radical prostatectomy, knee replacement surgery, hip replacement surgery, and scoliosis, utilization rates were 72, 60, 83, and 78 percent in 1993 compared with 50, 50, 58, and 58 percent in 2000, respectively. In 2000, 18 percent of patients were receiving a 1‐unit autologous transfusion. Depending on the surgical procedure, 85 to 95 percent of patients avoided allogeneic transfusion; this did not change significantly from 1993 to 2000. CONCLUSION: Patients participating in the PABD program successfully avoided allogeneic transfusion in over 85 percent of cases. However, declining utilization rates and frequent 1‐unit transfusions demonstrate the decreasing utility of PABD over time.
Biochemical and structural changes in RBCs stored with different plasticizers: the role of hexanol
Authors: Draper C.J. , Greenwalt T.J. , Dumaswala U.J. 
Published: September 2002

BACKGROUND: PVC containers are plasticized with di(2‐ethyl)hexylphthalate (DEHP) or a related phthalate. The toxicity of DEHP has been questioned. It has been proposed to use butyryltrihexylcitrate (BTHC) as the plasticizer. The purpose of this study was to determine if hexanol, a component of BTHC, plays a role in the preservation of RBCs stored in BTHC‐plasticized PVC bags. STUDY DESIGN AND METHODS: WBC‐reduced RBCs of ABO‐ and D‐matched blood groups were prepared in 1‐L polyolefin (PO) bags (PL732). Six 60‐g aliquots were transferred to transfer packs made of PL146 (DEHP‐plasticized) and PL2209 (BTHC‐plasticized) and four PO (PL732) packs. To the PL146 and PL2209 packs, 30 mL of AS‐1 was added. To three of the PO packs, 30 mL of AS‐1 with sufficient DEHP, BTHC, or hexanol to achieve a final concentration of 3 mM was added, and to the final PO pack, 30 mL of AS‐1 only was added (control). The units were stored for 6 weeks at 1 to 6°C. RBC ATP, hemolysis, morphology, membrane lipids, deformability, and fluidity were measured. RESULTS: ATP levels were not significantly different in any of the systems after 6 weeks. Compared to the PO bags, hemolysis was lowest in the PL146 containers and was also significantly lower (p < 0.006) in the PO bags with added DEHP, BTHC, or hexanol. The accumulation of vesicles was significantly less in the units stored in the PL146 and PL2209 than in the PO plastic with or without added plasticizers or hexanol (p ≤ 0.004). There was no significant difference in the formation of vesicles in any of the PO units (p > 0.05). There was no demonstrable change in the membrane fluidity of the RBCs during storage in any of the systems. The decrease in deformability was the same, and the losses of cholesterol and phospholipid during storage were similar in all the studies. CONCLUSIONS: The hexanol component of the BHTC plasticizer in a concentration of 144.6 μg per mL concentration suppresses hemolysis and vesiculation of RBCs during storage. The hexanol and DEHP that are slowly leached during storage have a greater effect in suppressing hemolysis and vesicle formation than when added extraneously to AS‐1 in PO containers.
QTc prolongation in apheresis platelet donors
Authors: Laspina Stefan J. , Browne Martin A. , McSweeney Ellen N. , Lawlor Jo , Whelan Denise M. , Kinsella Anthony I. , Murphy William G. 
Published: September 2002

BACKGROUND: Citrate infusion during apheresis procedures can cause lowering of the plasma ionized calcium leading to prolongation of the QT interval and hypotension. At the myocardial level, QTc measurement is a sensitive marker of subphysiologic calcium values caused by citrate toxicity. STUDY DESIGN AND METHODS: Seventy‐six regular platelet donors were recruited into this study. QTc intervals were measured continuously for 3 minutes at four different points during the apheresis procedures. The blood pressure was recorded every 5 minutes throughout the procedure. RESULTS: The baseline QTc value for men was 406.5 ± 13.1 milliseconds1/2 and for women was 417.6 ± 13.3 milliseconds1/2 (p = 0.0016). QTc prolongation occurred in all procedures in all donors. Maximum recorded values were significantly higher in women than in men (450.8 ± 20.8 vs. 424.8 ± 14.3 ms1/2; p = 0.0025). All QTc values returned to baseline by 15 minutes after the procedure. Changes in blood pressure were minimal and no donor experienced severe symptoms. CONCLUSIONS: QTc prolongation always occurs during plateletpheresis. This prolongation is greater in women than in men. This study indicates that it may be advisable to assess donors for family or personal history of syncope and family history of sudden death to exclude those at increased risk of arrhythmias because of asymptomatic carriage of a long‐QT gene. In addition baseline QTc measurement is a simple noninvasive procedure that could be applied to further studies with a view to enhancing donor safety in apheresis.
Seven‐day storage of single‐donor platelets: recovery and survival in an autologous transfusion study
Authors: Dumont Larry J. , AuBuchon James P. , Whitley Pamela , Herschel Louise H. , Johnson Adrienne , McNeil Deanna , Sawyer Sherrie , Roger Jill C. 
Published: September 2002

BACKGROUND: Bacterial screening may effectively reduce the morbidity and mortality risk associated with extended storage of platelets. Platelet viability then becomes the primary determinant of acceptable storage time. This study evaluates the effectiveness of platelets stored in plasma for 7 days. STUDY DESIGN AND METHODS: WBC‐reduced, single‐donor platelets (n = 24) were collected and stored by standard methods at two sites. Standard in vitro platelet biochemical and functional parameters were monitored over the storage period. On Days 5 and 7 of storage, platelets were alternately labeled with 51Cr and 111In and returned to the subject, and recovery and survival were determined. RESULTS: Component pH22°C was maintained in the range 6.2 to 7.61 through 7 days and did not detrimentally affect either in vitro or in vivo outcomes. In vitro platelet characteristics were adequately maintained over 7 days. Day 5 platelets had better recovery (63.0 ± 4.36 vs. 53.9 ± 4.36%, p < 0.0001) and survival (161 ± 8.1 vs. 133 ± 8.1 hr, p = 0.006) than Day 7 platelets adjusting for radioisotope, center, and donor effects. CONCLUSION: Although declines in recovery and survival were noted, these are less than used previously to gain licensure of 7‐day storage and are unlikely to be clinically significant. Extension of storage to 7 days could be implemented with bacterial screening methods to select out contaminated components without a significant effect on the platelet efficacy compared to 5‐day components.
Bone marrow stromal cells prepared using AB serum and bFGF for hematopoietic stem cells expansion
Authors: Yamaguchi Miki , Hirayama Fumiya , Wakamoto Shinobu , Fujihara Mitsuhiro , Murahashi Hideaki , Sato Norihiro , Ikebuchi Kenji , Sawada Ken‐ichi , Koike Takao , Kuwabara Mikinori , Azuma Hiroshi , Ikeda Hisami 
Published: September 2002

BACKGROUND: An ex vivo culture system was previously established for stem cell expansion using human marrow stromal cells and serum‐free medium. However, the stromal cells were prepared using long‐term culture medium containing horse serum and FCS, which may transmit infectious diseases of xenogeneic origin. In this study, therefore, a method was established to prepare stromal cells using an AB serum‐based medium. In the case that serum from a transplant recipient or PBPC donor is available, additional infectious diseases would not be transmitted. STUDY DESIGN AND METHODS: Cord blood CD34+ cells were cultured with thrombopoietin, stem cell factor, and flt3/flk2 ligand on a monolayer of human marrow primary stromal cells prepared using long‐term culture medium or AB serum‐based medium. After 2 weeks, clonogenic progenitor activity and SCID mouse‐reconstituting cell activity were assayed. mRNA expression of cytokines and Notch ligand by stromal cells was also examined. RESULTS: There were no remarkable differences in expansion‐supporting activity and mRNA expression between stromal cells established by the two methods. CONCLUSION: An ex vivo expansion system completely based on AB serum has been established.
Evaluating DNA tests of motherless cases using a Philippine genetic database
Authors: De Ungria M.C.A. , Frani A.M. , Magno M.M.F. , Tabbada K.A. , Calacal G.C. , Delfin F.C. , Halos S.C. 
Published: September 2002

BACKGROUND: In 5 percent of paternity determination cases, only DNA samples from the alleged father and child pairs are tested. The absence of the mother's DNA increases the probability of false paternity inclusions, which affects laboratories that use a limited number of DNA markers. The effect of coincidental matches between unrelated individuals on DNA tests of motherless cases was determined using the Philippine population genetic database of the National Capital Region (NCR). STUDY DESIGN AND METHODS: Seven short tandem repeat (STR) markers were used, namely HUMvWA, HUMTH01, HUMCSF1PO, HUMFOLP23, D8S306, HUMFES/FPS, and HUMF13A01. Values of the probability of paternity with (W) and without a mother (W‐mother) were determined using the equation W = cumulative likelihood ratio/cumulative likelihood ratio + 1). These values were determined for 50 volunteer families and compared with values calculated from randomly matched pairs in a reference NCR population database. RESULTS: The W and W‐mother values of the 50 families range from 96.48 to 99.99 percent and 79.76 to 99.99 percent, respectively. In the NCR database, 195 coincidental matches in seven STR loci out of 5253 possible pairs (3.71%) were detected with W‐mother values ranging from 12.47 to 99.83 percent. Of these, 53 and 10 random pairs have W‐mother greater than 95.0 and 99.0 percent, respectively. CONCLUSION: W was higher than W‐mother in the 50 families. However, the existence of unrelated individuals in the NCR database that randomly matched at seven STR loci and that has W‐mother values greater than 99.0 percent highlights the need for greater precaution when dealing with motherless cases.