Positional changes of maxillary central incisors following orthodontic treatment using single-crown implants as fixed reference markers.

OBJECTIVES: This follow-up study (1) compares tooth displacement of central incisors in patients with and without pre-implant orthodontic treatment and (2) investigates whether sex, age, or orthodontic retention have an effect on tooth displacement after the insertion of single-crown implants. MATERIALS AND METHODS: Fifty-seven patients - thirty-seven with (test group) and twenty without pre-implant orthodontic treatment (control group) - were rehabilitated with 89 single-crown implants in the upper maxilla. Clinical and radiographic data, clinical photographs, and dental casts were collected during baseline examinations after prosthetic rehabilitation and at the final follow-up examination at least 5 years later. A total of 114 dental casts were digitalized and aligned using a software program to measure changes in the positions of the central incisors. RESULTS: After a follow-up period of at least five years, 87% of the central incisors measured in the test group were displaced >0.25 mm vertically compared with 70% in the control group. Seventy-eight percent of the test group teeth had moved >0.25 mm horizontally compared with 55% in the control group. These differences were not significant, and there were no significant correlations with patient age or sex. CONCLUSION: The majority of patients had minor vertical (60%) or horizontal (67%) tooth displacement of the central incisors (0.25-0.75 mm) after a minimum follow-up period of 5 years. This study found no significant differences in tooth displacement comparing patients with and without pre-implant orthodontic treatment. No significant effect of sex, age, orthodontic retention, or implant location was observed on tooth displacement.

Non-intercepted dose errors in prescribing anti-neoplastic treatment: a prospective, comparative cohort study.

BACKGROUND: The incidence of non-intercepted prescription errors and the risk factors involved, including the impact of computerised order entry (CPOE) systems on such errors, are unknown. Our objective was to determine the incidence, type, severity, and related risk factors of non-intercepted prescription dose errors. PATIENTS AND METHODS: A prospective, comparative cohort study in two clinical oncology units. One institution used a CPOE system with no connection to the electronic patient record system, while the other used paper-based prescription forms. All standard prescriptions were included and reviewed. Doses were recalculated according to the guidelines of each institution, using the patient data as documented in the patient record, the paper-based prescription form, or the CPOE system. A non-intercepted prescription dose error was defined as ≥10% difference between the administered and the recalculated dose. RESULTS: Data were collected from 1 November 2012 to 15 January 2013. A total of 5767 prescriptions were evaluated, 2677 from the institution using CPOE and 3090 from the institution with paper-based prescription. Crude analysis showed an overall risk of a prescription dose error of 1.73 per 100 prescriptions. CPOE resulted in 1.60 and paper-based prescription forms in 1.84 errors per 100 prescriptions, i.e. odds ratio (OR) = 0.87 [95% confidence interval (CI) 0.59-1.29, P = 0.49]. Fifteen different types of errors and four potential risk factors were identified. None of the dose errors resulted in the death of the patient. CONCLUSIONS: Non-intercepted prescribing dose errors occurred in <2% of the prescriptions. The parallel CPOE system did not significantly reduce the overall risk of dose errors, and although it reduced the risk of calculation errors, it introduced other errors. Strategies to prevent future prescription errors could usefully focus on integrated computerised systems that can aid dose calculations and reduce transcription errors between databases.

Experienced and inexperienced observers achieved relatively high within-observer agreement on video mobility scoring of dairy cows.

Assessment of lameness prevalence and severity requires visual evaluation of thelocomotion of a cow. Welfare schemes including locomotion assessments are increasingly being adopted, and more farmers and their veterinarians might implement a locomotion-scoring routine together. However, high within-observer agreement is a prerequisite for obtaining valid mobility scorings, and within-observer agreement cannot be estimated in a barn, because the gait of cows is dynamic and may change between 2 occasions. The objective of this study was to estimate the within-observer agreement according to the observers' educational background and experience with cattle, based on video recordings with very diverse types of gait. Groups of farmers, bovine veterinarians, first- and fourth-year veterinary students, researchers, and cattle-inexperienced sensory assessors evaluated mobility using a 5-point mobility score system developed specifically for walking cows (n=102 observers). The evaluation sessions were similar for all groups, lasted 75 min, and were organized as follows: introduction, test A, short training session, break, and test B. In total, video recordings of 22 cows were displayed twice in a random order (11 cows in each test × 2 replicates). Data were analyzed applying kappa coefficient, logistic regression, and testing for random effects of observers. The crude estimates of 95% confidence interval for weighted kappa in test A and B ranged, respectively, from 0.76 to 0.80 and 0.70 to 0.75. When adjusting for the fixed effects of video sample and gait scoring preferences, the probability of assigning the same mobility score twice to the same cow varied from 55% (sensory assessors) to 72% (fourth-year veterinary students). The random effect of the individual observers was negligible. That is, in general observers could categorize the mobility characteristics of cows quite well. Observers who preferred to assess the attributes back arch or the overall mobility score (based on uneven gait) had the highest agreement, respectively, 69 or 68%. The training session seemed insufficient to improve agreement. Nonetheless, even novice observers were able to achieve perfect agreement up to 60% of the 22 scorings with merely the experience obtained during the study (introduction and training session). The relatively small differences between groups, together with a high agreement, demonstrate that the new system is easy to follow compared with previously described scoring systems. The mobility score achieves sufficiently high within-observer repeatability to allow between-observer agreement estimates, which are reliable compared with other more-complex scoring systems. Consequently, the new scoring scale seems feasible for on-farm applications as a tool to monitor mobility within and between cows, for communication between farmers and veterinarians with diverse educational background, and for lamenessbenchmarking of herds.

The effect of breed and feed-type on the sensory profile of breast meat in male broilers reared in an organic free-range system.

1. Studies on the sensory profiling of male broiler breast meat were carried out to evaluate the effect of two very different broiler breeds (JA757 and New Hampshire), two different feed types (broiler and grower feed) and age at slaughter (82 and 110 d). 2. The sensory profiling consisted of a pilot study, 4 training sessions, and finally the assessment. During the training session a panel of 9 assessors defined 17 attributes, which were used to describe the smell, texture and flavour of the breast fillets. Each attribute was evaluated on a 15-cm unstructured line scale. 3. The breast meat became significantly less hard, and more juicy and tender in the New Hampshire at 110 d of age, whereas the opposite was found in JA757, which also acquired a more "sourish" flavour with age. The smell of "sweet/maize" and "bouillon" became weaker with age in JA757, but not in New Hampshire. 4. Several significant differences in relation to the main factors of breed and age were found. The traditional broiler hybrid JA757 did best for most smell and flavour attributes, whereas New Hampshire did best for the texture attributes. Age had a negative effect on the flavours and smell attributes "fresh chicken", "neck of pork" and "sweet maize", but a positive effect on the texture attribute "crumbly". In addition meat was more "stringy" at 110 d of age. 5. The flavours "neck of pork" and "umami" were significantly improved when JA757 was fed on the broiler feed and when New Hampshire was given the grower feed. The meat smelt more "sourish" at 82 d of age and less "sourish" at 110 d of age when the grower feed was consumed. Meat was significantly harder and stringier when JA757 was fed on the grower feed. This was not the case for New Hampshire. In general, the meat was significantly less crumbly and stringier with the grower feed. 6. Overall a very distinct difference in sensory profile was found between the two breeds. In addition different slaughter ages and feeding strategies should be taken into consideration in a niche production based on alternative genotypes.

Glucagon stimulation test for estimating endogenous insulin secretion in dogs.

Fifty-one dogs (27 diabetic dogs, four that had recovered from diabetes and 20 healthy control dogs) were given 0.5 or 1.0 mg glucagon intravenously. Blood samples were taken before the injection and 10 and 20 minutes after it. Samples were analysed to determine C-peptide, insulin and glucose concentrations, and one sample from each dog was analysed for fructosamine. The median (interquartile range) concentrations of C-peptide in the samples taken at 10 minutes were 0.5 (0.3 to 0.8) nmol/l in the control dogs, 0.1 (0 to 0.2) nmol/l in the diabetic dogs, and 0.3 (0.2 to 0.4) nmol/l in the dogs that had recovered from diabetes. Seven of the 51 dogs showed mild adverse reactions after the injection of glucagon.

Implants and/or teeth: consensus statements and recommendations.

In August 23-25, 2007, the Scandinavian Society for Prosthetic Dentistry in collaboration with the Danish Society of Oral Implantology arranged a consensus conference on the topic 'Implants and/or teeth'. It was preceded by a workshop in which eight focused questions were raised and answered in eight review articles using a systematic approach. Twenty-eight academicians and clinicians discussed the eight review papers with the purpose to reach consensus on questions relevant for the topic. At the conference the consensus statements were presented as well as lectures based on the review articles. In this article the methods used at the consensus workshop are briefly described followed by the statements with comments.

Treatment of severe hypodontia-oligodontia--an interdisciplinary concept.

The authors' experience with oral rehabilitation of patients suffering from oligodontia (i.e. six or more congenitally missing permanent teeth, third molars excluded) is reported. The concept is based on an interdisciplinary team approach involving pedodontists, orthodontists, maxillofacial surgeons and prosthodontists. A series of 112 consecutive patients suffering from oligodontia were referred from 1997 to 2001. Ten of the patients (8.9%) suffered from ectodermal dysplasia. The total number of missing teeth was 1126, with an average of 10 per patient. Ninety-two patients had either finished treatment or were on an active treatment schedule. Of these, 97% underwent some kind of orthodontic treatment. Of the 112 patients, 51 had finished treatment at the end of the follow-up period (mean 28 months, range 1-68). Of these, fixed implant-supported prosthetic restoration was used in 90% to replace missing teeth, often combined with alveolar ridge augmentations (73%), sinus floor augmentation (43%), inferior alveolar nerve transposition (18%) and orthognathic surgery (27%). Early diagnosis, and comprehensive treatment planning with good coordination and timing of the individual treatment phases are decisive for a successful treatment outcome. The therapeutic concept is presented with special emphasis on surgical aspects.

Chinese hamster ovary cells resistant to the topoisomerase II catalytic inhibitor ICRF-159: a Tyr49Phe mutation confers high-level resistance to bisdioxopiperazines.

Anticancer drugs targeted to the nuclear enzyme DNA topoisomerase II are classified as poisons that lead to DNA breaks or catalytic inhibitors that appear to completely block enzyme activity. To examine the effects of the bisdioxopiperazine class of catalytic inhibitors to topoisomerase II, we investigated a Chinese hamster ovary (CHO) subline selected for resistance to ICRF-159 (CHO/159-1). Topoisomerase IIalpha content in CHO/159-1 cells was reduced by 40-50%, compared to wild-type CHO cells, whereas the beta isoform was increased by 10-20% in CHO/159-1 cells. However, the catalytic activity of topoisomerase II in nuclear extracts from CHO/159-1 cells was unchanged, as was its inhibition by the topoisomerase II poison etoposide (VP-16). No inhibition of topoisomerase II catalytic activity by ICRF-187 was seen in CHO/159-1 cells up to 500 microM, whereas inhibition was evident at 50 microM in wild-type CHO cells. VP-16-mediated DNA single-strand breaks and cytotoxicity were similar in the two sublines. ICRF-187 could abrogate these VP-16 effects in the wild-type line but had no effect in CHO/159-1 cells. Western blots of topoisomerase IIalpha after incubation of CHO cells with ICRF-187 demonstrated a marked band depletion, whereas this effect was completely lacking in CHO/159-1 cells, and an equal effect of VP-16 was observed in both lines. These data imply that the CHO/159-1 topoisomerase IIalpha lacks sensitivity to bisdioxopiperazines and that the mechanism of resistance in this cell line does not confer cross-resistance to topoisomerase II poisons, suggesting that mutations conferring resistance to bisdioxopiperazines can occur at sites distinct from those responsible for resistance to complex stabilizing agents. Accordingly, CHO/159-1 cDNA showed two heterozygous mutations in the proximal NH2-terminal part of topoisomerase IIalpha (Tyr49Phe and delta 309Gln-Gln-Ile-Ser-Phe313), which is in contrast to those induced by topoisomerase II poisons, which cluster further downstream. Site-directed mutagenesis and transformation of the homologous Tyr50Phe coding mutation in human topoisomerase IIalpha in a temperature-conditional yeast system demonstrated a high-level resistance to ICRF-193, compared to cells expressing wild-type cDNA, but none toward the poisons VP-16 or amsacrine, thus confirming that the Tyr50Phe mutation confers specific resistance to bisdioxopiperazines. Thus, these results indicate that the region of the protein involved in ATP-binding also plays a critical role in sensitivity to bisdioxopiperazines, a result consistent with the known requirement for the formation of an ATP-bound closed clamp for bisdioxopiperazine activity. These results may enable a more precise understanding of the interaction of topoisomerase II-directed drugs with their target enzyme.

Characterization of antioxidant activities of pulmonary surfactant mixtures.

Instillation of intratracheal surfactant is known to limit the morbidity and mortality of patients and animals with oxidant-induced lung injury. In this study we quantified the antioxidant properties of natural lung surfactant (NLS), consisting of 90% lipid and 10% protein, and of calf lung surfactant extract (CLSE) consisting of 99% lipid and 1% protein. NLS, but not CLSE, contained significant amounts of superoxide dismutase (SOD) and catalase activities (7 U SOD/mumol phospholipid (PL) and 1 U catalase/mumol PL). More than 90% of the SOD activity was abolished by 1 mM KCN, suggesting that this was the CuZn form of the enzyme. In addition, NLS significantly reduced extracellular H2O2 without losing its ability to reach minimum surface tensions below 1 dyn/cm upon dynamic compression. The NLS scavenging of H2O2 could not be accounted for by albumin. The presence of catalase and SOD activities in NLS was also verified by activity stains of proteins separated by native polyacrylamide gel electrophoresis. Intratracheal instillation of 7 ml of NLS (308 mumol PL) into rabbits significantly increased SOD content in type II cells isolated 12 h later. It is concluded that, in addition to promoting alveolar stability, instillation of pulmonary surfactant may offer significant protection to the alveolar epithelium by scavenging extracellularly generated partially reduced oxygen species and by enhancing intracellular antioxidant enzyme content.

Improved targeting of brain tumors using dexrazoxane rescue of topoisomerase II combined with supralethal doses of etoposide and teniposide.

Dexrazoxane (ICRF-187) is a catalytic inhibitor of the nuclear enzyme DNA topoisomerase II (topo II). It protects cells against topo II poisons, such as etoposide and teniposide, by hindering the DNA cleavage reaction of the target enzyme. We have previously shown that this antagonism also extends to an in vivo model. Thus, ICRF-187 protected mice against supralethal doses of etoposide and amsacrine, and the etoposide LD10 dose increased as much as 3.6-fold when combined with ICRF-187 (B. Holm, Cancer Chemother. Pharmacol., 38: 203-209, 1996). We describe here how scheduling of this drug combination can be optimized and used. Interestingly, ICRF-187 can protect when it is given after etoposide. Although timing is very critical here, ICRF-187 was able to completely protect when given 10 min after etoposide. This rescue principle resembles methotrexate rescue by folinic acid. We also found scheduling to be crucial because ICRF-187 did not protect when etoposide was given once a day for five days, whereas effective protection was seen when etoposide was used three times, once every four days. Similar investigations were performed with teniposide in combination with ICRF-187. The combination with ICRF-187 allowed a 3.4-fold teniposide dose escalation. Such dose escalations could be advantageous in specific situations. One such case is when the tumor is situated in a pharmacological sanctuary, e.g., in the brain. ICRF-187 is hydrophilic and does not cross the blood-brain barrier, whereas the lipophilic etoposide and teniposide do. Therefore, ICRF-187 would protect normal tissues and allow a cytotoxic dose of etoposide to reach the central nervous system (CNS). We therefore studied the combinations using L1210 or EHR2 cells inoculated into the CNS of mice. L1210 presented a leukemic CNS model with leptomeningeal spread and infiltration of liver, spleen, and lymph nodes, whereas EHR2 cells acted as a solid tumor with no evidence of extracerebral disease. In all experiments, the combination of high-dose etoposide and ICRF-187 was significantly superior to an equitoxic dose of etoposide alone. Such superiority was also seen when treatment was given on days 4, 8, and 12 after tumor inoculation. Here etoposide alone resulted in a mean increased life span of 12.3%, whereas the rescue regimen yielded an increase of 47% (P < 0.0001). In conclusion, DNA topo II rescue by catalytic inhibitors is a new strategy enabling significant epipodophyllotoxin dose escalations; in this study, we have demonstrated the superiority of this strategy in two in vivo CNS tumor models. This concept is now being tested in a clinical trial.

The determination of thyroid volume by ultrasound and its relationship to body weight, age, and sex in normal subjects.

Using a precise and accurate ultrasonic scanning technique we have measured the volume of the thyroid gland in vivo in 271 healthy subjects (13-91 yr old). In these subjects the mean (+/- SD) thyroid volume was 18.6 +/- 4.5 ml. A significant difference between males (19.6 +/- 4.7 ml; n = 139) and females (17.5 +/- 4.2 ml; n = 132) was found (P less than 0.001). The thyroid volume was significantly correlated with both body weight and age, described by: Y = 1.97 + 0.21 . x1 + 0.06 . x2, where Y is the thyroid volume (milliters), x1 is the body weight (kilograms), and x2 is the age (years). The influence of body weight on the thyroid volume was about 3 times that of age. The difference in thyroid gland volume between males and females was explained solely by a difference in body weight.

Tolerance induced by direct inoculation of donor antigen into the thymus in low and high responder rodents.

A novel approach to tolerance induction in rats was recently described where donor antigen is inoculated directly into the thymus along with a brief period of immunosuppression in a pretransplant strategy. To develop a strategy that has more clinical appeal, we evaluated the timing of donor antigen inoculation in relation to allografting, the use of frozen bone marrow as the antigen, and the dose response of purified T cells as the antigen in a low responder heterotopic heart allograft combination. Additionally, the success of this pretransplant strategy in different low and high responder strain combinations was defined. In tolerant low responder animals we evaluated in vitro and in vivo cellular immunity. Tolerant host strain naive CD8+ T cell responses to donor and third party stimulators were compared to determine if tolerance is related to the strength of the response of the T cell subsets to donor antigen. Frozen bone marrow can induce tolerance in a low responder combination. Additionally, the dose of purified T cells necessary for tolerance induction was 5 x 10(5) cells. The pretransplant strategy was successful in two low responder strain combinations, Lewis into Wistar Furth and Lewis into DA, but unsuccessful in all high responder strain combinations evaluated. Low responder animals unresponsive to donor heart allografts demonstrate intact cell-mediated immunity and donor-specific tolerance in vivo by rejecting third party but not second donor strain hearts. The in vitro responses of tolerant animals demonstrated donor-specific suppression of the MHC class II response but an intact (normal) response to third party stimulators by proliferation assays and IFN-gamma production, suggesting suppression at the CD4+ T cell subset level.

Induction of tolerance to heart allografts in rats using posttransplant total lymphoid irradiation and anti-T cell antibodies.

This study examined whether posttransplant anti-T cell monoclonal or polyclonal antibody therapy could provide a window of treatment to allow posttransplant total lymphoid irradiation (TLI) to induce tolerance. These experiments were conducted in a high responder strain combination of an ACI cardiac allograft into a Lewis rat. In this situation, treatment with antibody or posttransplant TLI alone is insufficient to induce tolerance, while similar treatments alone have been shown to induce tolerance in low responder strains. The affects of three anti-T cell therapies were compared: anti-CD4 mAb therapy, anti-CD3 mAb, and rabbit antithymocyte globulin (RATG). None of these antibody therapies alone prolonged graft survival indefinitely. Combining anti-CD4 therapy with posttransplant TLI markedly delayed rejection but failed to induce long-term graft survival. Tolerance could be induced by a combination of anti-pan T cell antibody (anti-CD3) and TLI, and, all grafts survived beyond 100 days. RATG failed to prevent graft rejection when used alone or in combination with TLI. However, posttransplant therapy with a combination of RATG, TLI, and single-donor blood transfusion resulted in graft survival beyond 100 days. Recipients bearing long-term donor grafts rejected third-party (PVG) grafts within 2 weeks. Low density donor bone marrow cells used instead of a blood transfusion did not facilitate tolerance. The results indicate that monoclonal or polyclonal anti-pan T cell antibodies, TLI, and a donor blood cell infusion function synergistically in facilitating tolerance to allografts in the posttransplant period.

Cardiac allograft prolongation in mice treated with combined posttransplantation total-lymphoid irradiation and anti-L3T4 antibody therapy.

Neonatal cardiac allograft survival was examined in mice treated with anti-L3T4 antibody, posttransplantation total lymphoid irradiation (TLI) or a combination of both therapies. Independently, both posttransplantation TLI and short-course antibody treatment allowed minimal prolongation. However, synergistic prolongation in graft survival was observed with the combination (synergistic) therapy. Fluorescence-activated cell sorter analysis of peripheral blood lymphocytes from animals treated with combined anti-L3T4 and posttransplantation TLI additionally revealed "synergy" with respect to the degree of peripheral lymphocyte depletion.

Mechanisms of tolerance to rat heart allografts using posttransplant TLI. Changes in cytokine expression.

Lewis rats were rendered tolerant to ACI heart allografts using a regimen of posttransplant total lymphoid irradiation (TLI), rabbit antithymocyte or antilymphocyte globulin (RATG or RALG), and a single donor blood transfusion. All three treatment modalities were required to induce tolerance. The mechanism of the maintenance of tolerance was investigated by comparing the secretion of cytokines in the MLR, and the expression of cytokine mRNA in the allografts of tolerant and nontolerant Lewis rats. Although, the 3H-thymidine incorporation and secretion of IL-2 was frequently comparable in the MLR from tolerant and nontolerant rats, the secretion of IFN-gamma was markedly reduced in the tolerant rats. This was reflected in a markedly reduced frequency of cells expressing IFN-gamma mRNA in the allografts of tolerant as compared with nontolerant hosts. The frequency of cells expressing IL-2 and IL-10 mRNA was also reduced, but no significant difference was observed for cells with IL-4 mRNA. Spleen cells from nontolerant rats rapidly rejected ACI allografts in irradiated adoptive hosts, but spleen cells from tolerant rats did not. Evaluation of the cytokine mRNA expression at early and late time points in the allografts of adoptive hosts showed a pattern similar to that of the primary hosts. Thus, the tolerant state was associated with a maintenance or elevation of IL-4 expression and a marked reduction of IFN-gamma expression. Previous reports have shown that TLI alone induced this shift in the early recovery phase after irradiation.

Coexistence of Th1- and Th2-type cytokine profiles in anti-CD2 monoclonal antibody-induced tolerance.

Anti-CD2 monoclonal antibody OX34 has been shown to suppress immunity in rodents in vitro and in vivo. To evaluate the effects of OX34 on vascularized allografts, Lewis (RT1(1)) hearts were transplanted heterotopically into Wistar Furth (RT1(u)) rats. A single 5 mg/kg intraperitoneal dose of OX34 administered at transplantation induced indefinite graft survival (mean survival time >140.3+/-12.3 vs. 12.7+/-0.7 control, P=0.001). The mixed lymphocyte response was partially inhibited at 60 days after transplant, returning to normal at 100 days. Donor-specific tolerance was confirmed by acceptance of second donor (>100 days, n=2) and rejection of third-party (mean survival time: 7.5+/-0.5 days, n=2) hearts. Immunohistochemical staining of allograft tissue from tolerant animals demonstrated abundant CD2+, CD4+, and CD8+ graft-infiltrating cells. To elucidate further the nature of these cells, we compared the expression of interleukin (IL)-2, IL-4, IL-10, and interferon (IFN)-gamma mRNA in allografted tissue from tolerant, acutely rejecting (AR), isografted, and naive animals using nonisotopic in situ hybridization. A significant increase in IL-2, IL-4, IL-10, and IFN-gamma mRNA was observed in graft-infiltrating cells of both tolerant and AR animals. IL-10 mRNA expression 4 days after transplant was significantly elevated in the OX34-treated compared to AR recipients. These data demonstrate that a single dose of OX34 at engraftment induces tolerance to vascularized allografts. Expression of both T helper 1 and T helper 2 cytokine mRNA profiles (IL-2/IFN-gamma and IL-4/ IL-10, respectively) are up-regulated locally in graft-infiltrating cells of AR and tolerant animal allografts.

Thrombus-related uptake and vascular clearance of 131 I-fibrin des-AABB as compared to 125 I-fibrinogen in patients with established venous thrombosis.

Thrombus-related uptake of 131 I-fibrin des-AABB has been compared to that of 125 I-fibrinogen in 13 patients with established venous thrombosis. Both tracers originated from a common pool of beta-alanine precipitated fibrinogen. Scan-recordings were performed as a radiofibrin (ogen) uptake test. Uptake characteristics of des-AABB fibrin were similar to those of fibrinogen, when measured as percentage of concomitant radioactivity over the heart. Due to its longer circulation time, fibrinogen was superior to fibrin des-AABB for the detection of venous thrombi. Circulating des-AABB fibrin was cleared biphasically, with an initial rapid decline followed by a gradual exponential decrease. Mean half-lives were 5.5 +/- SD 3.5 hr and 10 +/- SD 3.5 hr, respectively. The elimination rates were uninfluenced by thrombus activity, as judged by the fibrin(ogen) uptake test. Metabolic half-life of fibrinogen in the total material was 62 +/- SD 19 hr. Dissociation of fibrinogen and soluble des-AABB fibrin clearance rates was evident, describing their own, independent elimination patterns, probably reflecting different clearing mechanisms.

Antagonistic effect of the cardioprotector (+)-1,2-bis(3,5-dioxopiperazinyl-1-yl)propane (ICRF-187) on DNA breaks and cytotoxicity induced by the topoisomerase II directed drugs daunorubicin and etoposide (VP-16).

The effect of the bisdioxopiperazine cardioprotector ICRF-187 (ADR-529, dexrazoxan) on drug-induced DNA damage and cytotoxicity was studied. Using alkaline elution assays, ICRF-187 in a dose-dependent manner inhibited the formation of DNA single strand breaks (SSBs) as well as DNA-protein cross-links induced by drugs such as VP-16 (etoposide), m-AMSA [4'-(9-acridinylamino)-methanesulfon-m-anisidide], daunorubicin and doxorubicin (Adriamycin) which are known to stimulate DNA-topoisomerase II cleavable complex formation. Thus, 50% inhibition of DNA SSBs induced by 5 microM doxorubicin occurred already at equimolar ICRF-187. In contrast, ICRF-187 did not affect DNA SSBs induced by H2O2. In clonogenic assay, ICRF-187 in non-toxic doses antagonized both VP-16 and daunorubicin cytotoxicity in a dose-dependent manner. Our results indicate that the previously described acute in vivo protection by ICRF-187 against anthracycline toxicity may be due to inhibition of topoisomerase II activity. The antagonistic effect of ICRF-187 on daunorubicin cytotoxicity should be taken into consideration when planning clinical trials.

Theoretical investigation of high pressure phases of carbon dioxide

The recent discovery of a new solid phase of carbon dioxide ( CO2-V) has made it apparent that the properties of this vital chemical species are drastically altered under high pressure conditions. The reported transition at around 40 GPa from the Cmca phase ( CO2-III), which is a molecular solid, into the novel phase, which was observed to be quartzlike, clearly suggests a dramatic change of the chemical, electronic, and structural properties. We here present a theoretical analysis of the implications of this metamorphosis. At even higher pressures, we predict the existence of a very hard phase of the stishovite type.

Interferon-gamma and interleukin-10 messenger RNA are up-regulated after orthotopic liver transplantation in tolerant rats: evidence for cytokine-mediated immune dysregulation.

BACKGROUND: Immune regulation requires antigen recognition, signaling, activation, secretion of cytokines, and effector function by lymphocytes. Although there is redundancy in the activation and function of the immune response, some cytokines simultaneously promote and suppress different pathways of immunity. In the experiments reported here we compare cytokine gene expression within liver allografts from tolerant rats with normal and isografted liver tissue. We also compare the secretion of interferon-gamma (IFN-gamma) in the supernatant from mixed lymphocyte cultures by using peripheral blood lymphocytes stimulated against donor antigen. METHODS: Orthotopic liver transplantations were performed using the cuff technique without hepatic artery revascularization. Nonisotopic in situ hybridization (ISH) was used to detect and localize messenger RNA to specific cells within tissue. Antisense DNA probes were generated to interleukin-2 (IL-2), IL-4, IL-10, and IFN-gamma. One-way mixed lymphocyte cultures were set up against irradiated donor splenocytes, and the supernatant was collected to measure IFN-gamma by enzyme-linked immunosorbent assay. RESULTS: Expression of IFN-gamma and IL-10 was up-regulated in tolerant animals versus normal or isografted liver (p = 0.0002 and 0.0001, IFN-gamma and IL-10, respectively). In situ hybridization localized the expression of messenger RNA predominantly to the cytoplasm of the hepatocytes. Levels of IFN-gamma were higher in the supernatant from proliferating peripheral lymphocytes against donor antigen from tolerant animals versus naive control animals. CONCLUSIONS: Expression of IFN-gamma and IL-10 is up-regulated in hepatocytes from allograft tissue after orthotopic liver transplantation. We believe that the up-regulation of IL-10 cross-regulates the effector function of IFN-gamma and supports cytokine-mediated immune dysregulation, which may be a mechanism of tolerance after orthotopic liver transplantation in rats.