Design, synthesis, and conformational analysis of 3-cyclo-butylcarbamoyl hydantoins as novel hydrogen bond driven universal peptidomimetics.

A collection of systematically substituted 3-cyclo-butylcarbamoyl hydantoins was synthesized by a regioselective multicomponent domino process followed by easy coupling reactions. Calculations, NMR studies and X-ray analysis show that these scaffolds are able to project their side chains similar to common secondary structures, such as the α-helix and ß-turn, with favourable enthalpic and entropic profiles.

A new approach to the use of α-fetoprotein as surveillance test for hepatocellular carcinoma in patients with cirrhosis.

BACKGROUND: Surveillance for hepatocellular carcinoma (HCC) is recommended in patients with cirrhosis. As α-fetoprotein (AFP) is considered a poor surveillance test, we tested the performance of its changes over time. METHODS: Eighty patients were diagnosed with HCC (cases) during semiannual surveillance with ultrasonography and AFP measurement were recruited and matched for age, gender, etiology and Child-Pugh class with 160 contemporary cancer-free controls undergoing the same surveillance training group (TG). As a validation group (VG) we considered 36 subsequent patients diagnosed with HCC, matched 1 : 3 with contemporary cancer-free controls. α-Fetoprotein values at the time of HCC diagnosis (T0) and its changes over the 12 (Δ12) and 6 months (Δ6) before cancer detection were considered. RESULTS: In both TG and VG, >80% of HCCs were found at an early stage. In TG, AFP significantly increased over time only in cases. T0 AFP and a positive Δ6 were independently associated with HCC diagnosis (odds ratio: 1.031 and 2.402, respectively). The area under the curve of T0 AFP was 0.76 and its best cutoff (BC) was 10 ng ml(-1) (sensitivity 66.3%, specificity 80.6%). The combination of AFP >10 ng ml(-1) or a positive Δ6 composite α-fetoprotein index (CAI) increased the sensitivity to 80% with a negative predictive value (NPV) of 86.2%. Negative predictive value rose to 99%, considering a cancer prevalence of 3%. In the VG, the AFP-BC was again 10 ng ml(-1) (sensitivity 66.7%, specificity 88.9%), and CAI sensitivity was 80.6% with a NPV value of 90.5%. CONCLUSIONS: CAI achieves adequate sensitivity and NPV as a surveillance test for the early detection of HCC in cirrhosis.

A kinematic comparison of the locomotor pattern of horses sedated with detomidine alone and in combination with low doses of butorphanol.

BACKGROUND: Chemical restraint is often used to perform diagnostic and minor surgical procedures; α2 -adrenoceptor agonists are the most commonly used drugs; however, the combination with an opiate can induce a profound sedation. There is a lack of kinematic studies examining the effects of the combination of these drugs on locomotor patterns. OBJECTIVES: The objective of the study was to evaluate the duration of the effects of sedation with detomidine and detomidine combined with a low dose of butorphanol on the movement patterns of horses. STUDY DESIGN: The study was a controlled, randomised, blinded and crossover experiment. METHODS: Each of six horses was injected intravenously with saline (0.9%) solution (10 mL), detomidine diluted in saline solution (0.01 mg/kg bwt) or a combination of detomidine (0.01 mg/kg bwt) and butorphanol (0.02 mg/kg bwt) diluted in saline solution, in a random order. A single accelerometer positioned at the sacrum was used for gait assessment 15 min before (baseline) and 5, 15, 30, 45, 60, 75, 90, 105 and 120 min after each injection. Eight variables were measured, including speed, stride frequency, stride length, regularity, dorsoventral power, propulsive power, mediolateral power and total power; force of acceleration and the three components of power were calculated. The degree of sedation was measured by the ground-to-lip distance. RESULTS: There were significant differences among groups, with shorter effects after the injection of the combination of drugs, for most parameters. MAIN LIMITATIONS: A small number of horses were involved in the study. CONCLUSIONS: The combination of detomidine and butorphanol produces a shorter effect on almost all accelerometric parameters, probably due to the excitement produced by the opioid drug causing a quicker return to normal values. Accelerometry offers a method of objectively monitoring gait abnormalities in walking sedated horses.

Development and application of an enzyme-linked immunosorbent assay for detection of bovine viral diarrhea antibody based on Erns glycoprotein expressed in a baculovirus system.

The BVDV envelope glycoprotein E(rns)/gp48 and the C terminal 79 amino acids of the capsid protein coding region were expressed in a baculovirus system and antigenically characterized. Western blot assay was used to detect recombinant E(rns) (r-E(rns)) in infected insect cells using specific monoclonal antibodies. The r-E(rns) was then used in an indirect ELISA to detect BVDV specific antibodies in a panel of 540 well-characterized sera. Results of the r-E(rns) ELISA were compared to those obtained with a commercially available competitive ELISA targeting anti-NS2/3 antibodies. A good correlation was observed between the 2 ELISA (kappa = 0.916, 95% C.I.: 0.876, 0.956). Using the commercial NS2/3 ELISA as the reference test, the relative sensitivity of r-E(rns) ELISA was 97.5% (95% C.I.: 94.3%, 99.1%) and the relative specificity was 93.9% (95% C.I.: 89.4%, 96.9%), while relative specificity was 100% (95% C.I.: 97%, 100%) using true negative sera (derived from a negative herd). All but 1 antigen positive animals (n = 36) tested negative in the r-E(rns) ELISA; among them all 22 confirmed PI animals were negative by r-E(rns) ELISA. The ability of r-E(rns) ELISA to identify cattle immunized with inactivated vaccine was also demonstrated in a small group of cattle, compared to an NS2/3 antibody ELISA. Results suggest that r-E(rns) ELISA represents an alternative test for antibody generated by natural infection or BVDV vaccination.

Proliferation signal inhibitors in transplantation: questions at the cutting edge of everolimus therapy.

While advances in immunosuppressive therapy have allowed dramatic improvements in the control of acute allograft rejection, there is still a need to improve long-term graft and patient survival rates following renal and heart transplantation. Among the recognized threats to long-term organ survival are chronic allograft dysfunction in the form of chronic allograft nephropathy and cardiac allograft vasculopathy, with long-term patient morbidity and mortality further compromised by higher than normal rates of posttransplant cardiovascular disease, infection, and malignancy. A growing body of evidence finds that the selection and dosing of immunosuppressive therapies can have great influence on long-term transplantation outcomes. Early evidence suggests that the proliferation signal inhibitors (PSIs), everolimus and sirolimus, might offer effective immunosuppressive activity together with antiproliferative effects that may address some of the unmet needs in the long-term therapeutic management of the posttransplant patient. This review summarizes the emerging evidence for employing PSI-based immunosuppression to seek a balance between the goals of maximizing graft and patient survival, while minimizing the risks of adverse events and long-term complications. Based on the proceedings of an international gathering of nephrologists, cardiologists and surgeons at the inaugural PSI Forum meeting "Proliferation signal inhibitors in transplantation: questions at the cutting edge," this paper aims to provide both an evidence base and practical guidance for transplant physicians seeking to optimize their use of PSI treatment and highlights avenues of ongoing research into the clinical potential of this class of immunosuppressive therapy.

Acute rejection after heart transplantation: noninvasive echocardiographic evaluation.

OBJECTIVES: The purpose of this study was to assess the reliability of echocardiography in the noninvasive diagnosis of acute rejection in heart transplant recipients. BACKGROUND: Although echocardiographic results seem to correlate well with allograft rejection, published data are limited and contradictory. METHODS: In 130 transplant recipients, 1,400 serial echocardiograms were recorded within 24 h of endomyocardial biopsy. Increased wall thickness, myocardial echogenicity, pericardial effusion, shorter pressure half-time, isovolumetric relaxation time and a decrease in left ventricular ejection fraction were considered markers of rejection. RESULTS: The distribution of echocardiographic markers revealed highly significant differences between bioptically graded moderate, mild and no rejection and between untreated and treated rejection episodes (both chi-square test, p < 0.0001). Specificity was 98.6% for two markers, but sensitivity was good (80%) for only moderate rejection because of the large number of false negatives in untreated patients with mild rejection. In untreated patients, there was a highly significant difference in the number of echocardiographic criteria between a benign and nonbenign outcome (chi-square test, p < 0.0001). In treated patients, the significant difference in the variation in echocardiographic criteria between favorable and unfavorable responses after 1 week was more pronounced after 2 weeks (t test, p < 0.01 vs. < 0.001). Diastolic indexes and pericardial effusion at 2 weeks seemed to be predictive of therapeutic response. CONCLUSIONS: Poor sensitivity to mild rejection indicates that serial echocardiography cannot supplant endomyocardial biopsy in the early diagnosis of acute rejection, but it seems to be a reliable noninvasive means of identifying acute rejection requiring intensified immunosuppressive therapy and of evaluating outcome.

Reflex vasopressin and renin modulation by cardiac receptors in humans.

Animal studies have shown that vasopressin secretion is modulated by arterial baroreceptors and cardiopulmonary volume receptors. Whether this is the case also in humans is controversial, however. To determine whether vasopressin is reflexly modulated by cardiac volume receptors, we studied the effect on plasma vasopressin (venous blood, radioimmunoassay) of reducing venous return and left ventricular end-diastolic diameter (echocardiography) by producing a 20-minute lower body negative pressure in 14 healthy subjects (aged 49.3 +/- 3.8 years, mean +/- SEM). The data were compared with those of 14 age-matched heart-transplant recipients, i.e., subjects with cardiac denervation. In healthy subjects, lower body negative pressure at -15 mm Hg caused a modest reduction in left ventricular end-diastolic diameter (-5 +/- 3.4%) and no change in vasopressin, whereas lower body negative pressure at -37.5 mm Hg caused a more marked reduction in left ventricular end-diastolic diameter (-12 +/- 2.5%) and a small, variable, but overall statistically significant (p < 0.05) increase in vasopressin (+145 +/- 46%, p < 0.01). The left ventricular end-diastolic diameter changes induced by the two lower body negative pressure stimuli were similar in heart-transplant recipients, but the vasopressin increase seen with the lower body negative pressure at -37.5 mm Hg was abolished. The marked increase in plasma renin activity and forearm vascular resistance induced by lower body negative pressure in healthy subjects was also abolished or drastically attenuated in heart-transplant recipients.(ABSTRACT TRUNCATED AT 250 WORDS)

Synthesis and pharmacological evaluation of enantiomerically pure 4-deoxy-4-fluoromuscarines.

Four isomers of [(4-fluoro-5-methyl-tetrahydrofuran-2-yl)methyl]trimethylammonium iodide (4-deoxy-4-fluoro-muscarines) were prepared in enantiomerically and diastereomerically pure form from (S)-(-)-methyl 4-methylphenyl sulfoxide, ethyl fluoroacetate, and allyl bromide. Their absolute configurations were assigned by 1H NMR analyses. The four optically pure compounds were tested in vitro on guinea pig and their muscarinic potency was evaluated at M3 (ileum and bladder) and M2 (heart) muscarinic receptor subtypes. Compound 1a, the most potent isomer of the series, was also tested in vivo on pithed rat and its muscarinic activity at the M1 receptor subtype was compared with that of muscarine. Moreover, affinity and relative efficacy were calculated in vitro for this compound at M2 (heart force and rate) and M3 (ileum and bladder) receptors in order to investigate muscarinic receptor heterogeneity. The 4-deoxy-4-fluoromuscarines display a similar trend of potency as the corresponding muscarines and compound 1a shows differences in the affinity constants among the studied tissues. Replacement of a hydroxyl group for a fluorine atom in the 4 position of muscarine produces 1 order of magnitude increase in affinity for cardiac M2 muscarinic receptors controlling rate, while the affinity at cardiac M2 muscarinic receptors controlling force is unchanged, opening the possibility of a further classification of cardiac muscarinic receptors.

Significance of pericardial effusion after heart transplantation.

The aim of this study was to evaluate the clinical significance of pericardial effusion after heart transplantation and to assess its correlation with acute rejection. One hundred fifty transplanted patients were followed up for the first year: serial echocardiographic studies were performed on the same day as were the endomyocardial biopsies; hemodynamic studies and coronary angiographies were performed 1 year after transplant. Ten days after surgery, pericardial effusion was absent in 77 patients, small in 52, moderate in 14, and large in 7, and was significantly related to severe postoperative bleeding (p < 0.001). Patients were classified according to the presence and the course of pericardial effusion in group A (absence or disappearance of previous pericardial effusion within 1 month, 107 patients) and in group B (onset, persistence, or increase in pericardial effusion, 43 patients). One hundred nineteen patients experienced > or = 1 acute rejection episode. The evolution of pericardial effusion was different (p < 0.0001) according to the number of acute rejection episodes and biopsy specimens showing acute rejection, histologic grading and time of the first episode, and histologic grading of the most severe acute rejection episode. Furthermore, there was a significant correlation with the cumulative duration of acute rejection episodes (p < 0.005) and the presence of previous cardiac surgical history (p < 0.007), but no correlation with cardiac transplant vasculopathy or with a positive weight mismatch. This study suggests that pericardial effusion in transplant recipients is associated with a higher incidence and more severe histologic grading of acute rejection episodes; its presence indicates the need for stricter monitoring of acute rejection.

Activation of a ribosomal protein S6 kinase during the 4-dimethylaminoazobenzene-induced rat hepatocarcinogenesis.

During the induction of 4-dimethylaminoazobenzene (DAB) hepatocarcinogenesis there was a progressive increase in the activity of a kinase which specifically phosphorylated S6 ribosomal protein in vitro. Liver tumour tissue (hepatocellular carcinoma and cholangioma) showed maximal activation of this kinase and elevated levels of S6 phosphorylation. Control rats fed with the same diet containing no dye showed a gradual decline of this activity, with low or lacking phosphorylation at the end of the experimental regimen, suggesting close correlation between tumor cell growth and phosphorylation of this ribosomal protein, under these conditions.

An ICRU 50 radiotherapy treatment chart.

We illustrate a radiotherapy treatment chart elaborated to fulfil the necessity for clarity in reporting information about radiotherapeutic treatment. The schematic configuration of the chart results from the experience and the cooperation of physicists, physicians and technicians, and an effort has been made to satisfy Levels 2/3 of the ICRU 50 recommendations. The chart has been divided into four sections corresponding to different kinds of information: a cover sheet, a section containing data about the treatment planning geometry and the console parameters adopted, a section showing dosimetric data, and a section showing treatment data. The chart seems to give a good level of accuracy in reporting treatment plan information.

Interphysician variability in defining the planning target volume in the irradiation of prostate and seminal vesicles.

With the improvements in treatment accuracy the risk exists of over-reliance on the capability of the physician to estimate the extent of the tumour. We assessed the variability between six radiotherapists in defining the planning target volume (PTV) on CT slices for three prostate tumour cases. Percentage differences between measured volumes and mean values calculated for each case ranged from -53.64 to +60.48% (SD 36.00%). There is a considerable variation in delineating the PTV, both in the cranio-caudal direction and in the in-slice extension of the areas drawn on each slice (standard deviations ranged from 0.35 to 2.64 cm2). We also checked the uncertainty in the shape and position of the contours on each CT image. The analysis was performed on three slices of one test case. As we expected, the uncertainty seems largest for seminal vesicle slices and smallest for prostatic apex slices. These results endorse the need for uncertainty analysis of all departmental processes in order to define a detailed protocol and consequently to minimize the interphysician differences in PTV delineations.

Restrictive criteria for heart transplantation candidacy maximize survival of patients with advanced heart failure.

BACKGROUND: The shortage of organ donors and the amelioration of medical management of advanced heart failure mandate strict selection of heart transplant candidates on the basis of the need and probability of success of transplantation, with the aim of maximizing survival of patients with advanced heart failure, both with and without transplantation. This study analyzes the impact of restricting the criteria for heart transplantation candidacy on the outcome of patients with advanced heart failure referred for transplantation. METHODS: Survival and freedom from major cardiac events (death, resuscitated cardiac arrest, transplantation while supported with inotropes or mechanical devices) were compared between patients listed during 1990 to 1991, when standard criteria were applied (group 1, n = 118), and patients listed during 1993 to 1994, when only patients requiring continuous/recurrent intravenous inotrope therapy in spite of optimized oral medications and outpatients showing actual progression of the disease were admitted to the waiting list (group 2, n = 88). Survival and freedom from cardiac events (defined as above plus listing in urgent status) were also calculated in stable outpatients evaluated in 1993 to 1994, who were potential heart transplant candidates according to standard criteria but were not listed because of restrictive criteria (group 3, n = 52, New York Heart Association functional class > or = III, mean echocardiographic ejection fraction 0.22 +/- 0.05, mean peak oxygen consumption 12.3 +/- 1.5 ml/kg/min, mean follow-up 19 +/- 10 months). RESULTS: Thirty-one percent, 40%, and 50% of group 1 patients versus 58%, 65%, and 77% of group 2 patients underwent transplantation within 3, 6, and 12 months after listing (p < 0.0007). The 1- and 2-year survival rates after listing were 80% and 71% in group 1 versus 85% and 84% in group 2 (p < 0.0001). Freedom from death/urgent transplantation was lower in group 2 than in group 1 (55% and 48% versus 72% and 59% at 6 and 12 months, respectively; p < 0.0001). In patients undergoing transplantation, the postoperative survival rate was similar (87% and 91% at 2 years in group 1 and group 2, respectively). Two years after heart transplantation candidacy was denied, 86% of group 3 patients were alive, and 74% were event-free. CONCLUSIONS: Restricting the admissions to the waiting list to patients with refractory/progressive heart failure improved survival rates after listing by increasing the probability to undergo transplantation in a short time. Selection of most severely ill candidates did not affect postoperative survival. Survival and freedom from cardiac events were good in patients with advanced but stable heart failure, in spite of their severe functional limitation. Thus restrictive criteria for heart transplantation candidacy allows maximal survival benefit from both medical therapy and transplantation.

A semiquantitative approach to the evaluation of acute cardiac allograft rejection at endomyocardial biopsy.

BACKGROUND: Histopathologic criteria for grading of acute cardiac allograft rejection are focused on the most severe lesion that is recognized among the myocardial fragments provided by each endomyocardial biopsy specimen. Considering the distribution of rejection lesions among all the fragments improved the accuracy in characterizing the severity of rejection in pathologic studies. This study was undertaken to verify the usefulness of a semiquantitative evaluation of endomyocardial biopsy specimens, consisting of the calculation of the proportion of fragments showing rejection in the clinical setting. METHODS: Of the 2386 biopsy specimens obtained during the first posttransplantation year in 168 consecutive cardiac allograft recipients, 290 biopsy specimens constituted by > or = 3 adequate fragments and showing rejection not followed by treatment (n = 159) or being the first biopsy specimen prompting treatment with augmented immunosuppression for that rejection episode (n = 131) were selected. These biopsy specimens (index biopsy specimens) were grouped according to whether rejection was present in < or = 33%, > 33% to < or = 67%, and > 67% of the fragments. The rejection grade (according to the standardized grading system) and the proportion of fragments positive for rejection were correlated with the occurrence of clinical symptoms and signs of rejection at index biopsy and with the results of the next biopsy. RESULTS: Rejections graded > or = 3A were more frequently symptomatic (36% vs 9% for those graded < 3, p < 0.0001), as were those involving increasing proportions of fragments (< or = 33%: 5 of 124, 4%; > 33 to < or = 67%: 13 of 99, 13%; > 67%: 19 of 67, 28% [p < 0.0001]). Spontaneous resolution after untreated biopsies was more frequent in focal (grade 1A and 2) than in diffuse mild (1B) rejections (68% vs 38% [p < 0.04]), whereas progression to grade 3A or greater was less frequent (4% vs 27% [p < 0.01]). Increasing proportions of positive fragments were associated with lower frequencies of spontaneous resolution (p < 0.05) and higher frequencies of worsening (9%, 22%, 43% [p < 0.009]) or progression to grade 3A or greater (2%, 6%, 28% [p < 0.005]). Complete resolution after treatment was less frequent for increasing proportions of positive fragments at index biopsy (80%, 66%, 49% [p < 0.05]). CONCLUSIONS: Diffuse versus focal rejection pattern and the proportion of positive fragments seem to be clinically relevant in terms of occurrence of symptoms, spontaneous evolution, and response to treatment.

Prognostic indices in heart transplant candidates after the first hospitalization triggered by the need for intravenous pharmacologic circulatory support.

BACKGROUND: Patients with heart failure refractory to optimal oral pharmacologic therapy have a dismal short term prognosis. Heart transplantation is the only therapy shown to improve survival in these patients. Unfortunately, due to the critical shortage of donor organs, approximately 30% of listed patients with end-stage heart failure die before a suitable donor heart becomes available. The principal aim of this study was to determine whether intravenous pharmacologic circulatory support favorably influences the clinical course of heart transplant candidates or whether mechanical circulatory support should be instituted in this high risk patient population. METHODS: Data from 154 consecutive hospitalizations in 125 patients 49+/-12 years were retrospectively reviewed. The product limit method was used to estimate survival. Multiple logistic regression analysis was used to identify the clinical and hemodynamic variables that independently predict outcome after each admission in which heart transplantation did not occur. RESULTS: One year survival for the study population was 65%. This survival is significantly lower than the 91% 1 year survival in similarly ill patients undergoing heart transplantation. The Cox proportional hazard method identified serum bilirubin, blood urea nitrogen (BUN), serum sodium levels and right atrial pressure as independent prognostic indices. Serum bilirubin, BUN levels and duration of intravenous pharmacologic circulatory support were associated with a poor outcome. A composite index including serum bilirubin and BUN levels predicted outcome with a sensitivity and specificity of 79% and 77%, respectively. The addition of pharmacologic support duration increased the model's sensitivity to 95%, but did not significantly alter specificity that was 74%. Of the 125 patients hospitalized due to the need to initiate intravenous pharmacologic support for the first time (index hospitalization), 69 (55%) were discharged after optimization of medical therapy. Of 21 patients who did not undergo transplantation during the follow-up period, 18 (86%) died within 2 years of the index hospitalization. The duration of intravenous pharmacologic support beyond which prognosis dramatically worsens without heart transplantation is 21 days. CONCLUSION: Heart transplant candidates who require intravenous pharmacologic circulatory support for more than 21 days and do not receive a suitable donor heart within this period of time have a high mortality. Alternative therapies, such as implantation of a mechanical circulatory assist device should be considered in this high risk population.

A short synthetic pathway to a fully-functionalized southern hemisphere of the antitumor macrolide bryostatin 1.

[reaction--see text] An 18-step asymmetric synthesis of the bryostatin 1 "southern hemisphere" fragment (1) has been developed. Key steps include an aldol reaction between 6 and 7 and a dehydration to establish the (E)-exocyclic alkene in 2 and a stereoselective Luche reduction and protection with TESOTf to access 1.

Junin virus infection of Callithrix jacchus: pathologic features.

Infection of Callithrix jacchus, a New World primate, with the prototype strain of Junin virus produced a severe disease. The animals developed multifocal hemorrhages and characteristic microscopic lesions such as meningoencephalitis, interstitial pneumonia, lymphocytic depletion of lymphatic tissue, hepatocytic necrosis, and a variable decrease in bone marrow cellularity. High virus concentrations correlated with lesions, and with the presence of viral antigenic determinants as revealed by immunofluorescent methods. With the exception of central nervous system damage, the morphological features and immunohistochemical and viral findings were similar to those recorded in human Argentine hemorrhagic fever.