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Minor species/minor indications: legal provisions, definition criteria and policies to be considered.

The problem of availability of immunological products in minor species and minor indications/uses is complex and should be well defined. Data for species are available, but not for minor uses. "Case-by-case" decisions should be avoided, as far as possible. The following categories can be recognized: (a) a vaccine has not been authorized anywhere; (b) a vaccine is authorized for major species/indications only; (c) an authorized vaccine exists in another Member State and (d) a vaccine has been withdrawn. Old, well established products, with limited data for an updated dossier could be the problem in categories "c" and "d". Proposed measures and incentives include: "cascade" (not recommended), human orphan-like drug policy, provisional authorization, acceptance of bibliographical data (if justified), procedural and financial assistance. Standards of quality, safety and efficacy cannot be minimized, but specific tests can be considered.

Animals↗

On the mechanism of coagulation inhibition on surfaces with end point immobilized heparin.

A well established technique to improve blood compatibility of artificial materials for use in the circulation is to coat the surface with heparin. The present report describes the antithrombin mediated inhibition of thrombin and factor Xa by surfaces modified with end point immobilized heparin. The reaction was followed by conventional chromogenic substrate based enzyme assays as well as by immunological measurement of the enzyme inhibitor (thrombin-antithrombin) complex formation. Both enzymes were rapidly inactivated by heparin surfaces after selective presaturation with antithrombin on the immobilized high affinity heparin molecules. The thrombin inhibitory capacity was enhanced when both high and low affinity heparin were preadsorbed with inhibitor. The main part of the thrombin-antithrombin complex formed remained bound to the surface, however, without functionally blocking the activity of the high affinity sequence of the immobilized heparin. Aliquots of recalcified plasma were slowly rotated in loops of heparinized tubing to investigate whether the main thromboresistant function of the surface was exerted at the level of thrombin or by inactivation of preceding enzymes. After 1 h no visible clotting occurred and only trace amounts of thrombin (0.07 IU/ml), measured as thrombin-antithrombin complexes, had been formed. In non-heparinized loops and in the test tube plasma clotted after 20 min. The thrombin generation when clotting occurred was in the order of 10 IU/ml. It is concluded that the immobilized heparin mediates inhibition of the coagulation cascade prior to prothrombin activation.

Adsorption↗

In vitro effect of hemodilution on activated clotting time and high-dose thrombin time during cardiopulmonary bypass.

BACKGROUND: Extreme dilution of clotting factors, as may occur during pediatric or neonatal cardiopulmonary bypass, often leads to inadequate monitoring of anticoagulation with activated clotting time (ACT). In this study we postulate that the high-dose thrombin time (HiTT) is less influenced by extreme dilution of clotting factors because it stimulates clotting through the common pathway. METHODS: Heparinized prebypass blood was obtained from 30 adult cardiac surgical patients and was diluted in a laboratory setting with saline solution to mimic the clinical clear prime solution (group I; n = 10), with saline solution containing similar heparin as in the prebypass blood (group II; n = 10), and with fresh frozen plasma to substitute clotting factors in the diluted blood (group III; n = 10). Blood was diluted to four different degrees: a control without dilution, 25%, 50%, and 75% dilution. The ACT and HiTT were measured and compared. RESULTS: In group I, significant prolongation of ACT was observed in blood diluted to 75% as compared with the nondiluted blood (p < 0.01). In contrast, HiTT was not prolonged at any degree of dilution but reduced proportionally to dilution up to 75%, reflecting the concomitant reduction of heparin. In group II, ACT increased at 25% dilution (p < 0.01) whereas HiTT increased at 50% dilution (p < 0.01). In group III, no prolongation of ACT or HiTT was found in any degree of dilution. Furthermore, adding fibrinogen to the diluted blood (n = 4) did not cause ACT to recover at 75% dilution, suggesting that dilution of other factors in the early clotting cascade rather than fibrinogen alone increases ACT. CONCLUSIONS: These results imply that when blood is extremely diluted during cardiopulmonary bypass with a clear prime without substituted clotting factors, HiTT is a better test than ACT for anticoagulation monitoring.

Adult↗

Tissue factor induces migration of cultured aortic smooth muscle cells.

Tissue factor (TF) plays a key role as a primary initiator on the extrinsic coagulation cascade. Recently, upregulation of TF has been reported in human atherosclerotic lesions. We investigated the effects of TF on migration and proliferation of cultured smooth muscle cells (SMCs) from rabbit aortas. We tested three kinds of recombinant human TF (L-TF: the full length of TF with relipidation, NL-TF: the full length of TF without relipidation, and S-TF: a soluble form of TF1-219). Only L-TF had coagulant activity. All kinds of TF showed the chemotactic migration activity for SMCs. The migration ability of TFs was comparable to those of platelet-derived growth factor (PDGF)-BB and basic fibroblast-growth factor (bFGF), and was inhibited by anti-TF polyclonal and monoclonal antibodies. On the other hand, none of the forms of TF induced SMC proliferation. These results indicate that TF is not only a coagulation factor but also a strong chemotactic factor for vascular SMCs, and suggest that TF could play an important role in atherogenesis as well as in hemostasis and thrombosis.

Animals↗

Inhibition of different intracellular signal cascades in human pancreatic cancer cells.

BACKGROUND/AIM: Pancreatic cancer is still a malignant disease with a poor prognosis. Except for surgery, no curative treatment has been found, albeit large research efforts. Agents, such as growth factors and hormones, have been shown to stimulate cell proliferation, whereas their receptor antagonists have been less efficient to inhibit cell proliferation. The aim of this study was to examine the effect of inhibitors of the intracellular signal cascades on pancreatic cancer cell number. MATERIALS AND METHODS: A cell line was developed from a patient with pancreatic cancer and subcloned to three generations. The four cell lines were grown in serum-free medium. The effects of PD98059, LY294002, rapamycin and its analogue CCI-779 were tested in dose-response experiments. The chemotherapeutic agent gemcitabine, with or without combination of the other potential inhibitor drugs in different concentrations, was also examined. The cell number was evaluated with the XTT method. RESULTS: PD98059 reduced the cell number in all the cell lines tested. At a concentration of 10(-4) M the cell number was reduced by 50-90%. LY294002 reduced the cell number by 40-50% at the same concentration. Two of four cell lines had their cell number reduced by CCI-779 by 60%, whereas the other two cell lines were reduced by 30%. Rapamycin or gemcitabine alone had no or only moderate effect on single cell lines. Different combinations of CCI-779 and gemcitabine led to reduction of the cell number by about 50% in concentrations up to 10(-7) M. CONCLUSION: Inhibitors of the intracellular signal cascades can reduce the cell number of human pancreatic cancer cell lines. Inhibitors of the mitogen-activated protein kinase downstream signalling cascades seem to be more efficient than the other inhibitors. PD98059 and CCI-779, in combination with gemcitabine, could be worth studying in clinical conditions.

Antibiotics, Antineoplastic↗

Development and validation of a deep learning model based on cascade mask regional convolutional neural network to noninvasively and accurately identify human round spermatids.

INTRODUCTION: The difficulty of identifying human round spermatids (hRSs) has impeded applications of the human round spermatid injection (ROSI) technique. RSs can be accurately screened through flow cytometric analysis utilizing the Hoechst fluorescence profile reflecting DNA, but this method is not suitable for isolating hRSs due to the toxicity associated with Hoechst staining. OBJECTIVE: To evaluate the capacity of a deep learning model grounded in a cascade mask region-based convolutional neural network (R-CNN) for the noninvasive and accurate identification of hRSs. METHODS: In this study, we presented the development and validation of a deep learning model for identifying hRSs through the analysis of 3457 optical light microscope images of sorted hRSs obtained via flow cytometric analysis. The model's accuracy and specificity were evaluated by calculating the mean average precision (mAP). Furthermore, a double-blind experiment was conducted to access the reliability of the proposed model in accurately identifying hRSs. It detected the expression of protamine (PRM1) and/or peanut lectin (PNA), which are established markers for RSs. RESULTS: Our deep learning-based model demonstrated a high precision, achieving a mAP of over 0.80 for isolating hRSs in test datasets. The expression of PRM1 and/or PNA was observed in all cells noninvasively selected by our AI model during an independent double-blind test. This phenomenon confirmed the accuracy and effectiveness of the proposed model. The model's capability for noninvasive and accurate isolation of hRSs among spermatogenic cells highlighted its robustness and generalizability for clinical applications. CONCLUSION: The deep learning AI model based on a cascade R-CNN has the ability to accurately identify hRSs among spermatogenic cells. The application of this noninvasive method, which requires no additional procedures in clinical practice, is able to facilitate the widespread implementation of ROSI technique. Therefore, it can provide patients with spermatogenic arrest the opportunity to become biological fathers.

Humans↗

Parallel kinase cascades are involved in the induction of LTP at hippocampal CA1 synapses.

To identify the enzymes involved in the induction of N-methyl-D-aspartate (NMDA) receptor-dependent long-term potentiation (LTP) at CA1 synapses of two-week-old rats we have tested various kinase inhibitors. Surprisingly, given the large body of evidence supporting a role for calcium/calmodulin-dependent protein kinase II (CaMKII) in LTP, inhibition of this enzyme did not affect the induction of LTP at this age. Similarly inhibition of protein kinase A (PKA) or protein kinase C (PKC) was also without effect. However, inhibition of CaMKII together with inhibition of either PKA or PKC fully blocked the induction of LTP. These experiments reveal, unexpectedly, the existence of two parallel kinase pathways, one involving CaMKII and the other PKA and PKC, either of which can fully support the induction of LTP, at this stage of development.

Animals↗

Production of tumor necrosis factor-alpha, interleukin 1-beta, interleukin 2, and interleukin 6 by rat leukocyte subpopulations after exposure to substance P.

The interaction between components of the nervous system and multiple target cells in the cutaneous immune system has been receiving increasing attention. Recently, the involvement of neuropeptides has been demonstrated to play an important role in the inflammatory cascade. Neuropeptides such as Substance P are released by cutaneous neurons and modulate the function of immunocompetent and inflammatory cells as well as epithelial and endothelial cells. Substance P has been shown to function as a mediator for cell proliferation, cytokine production, and as an upregulator of various cell surface receptors. In this study, we show the effect of Substance P on the production of Tumor Necrosis Factor-alpha, Interleukin 1-beta, Interleukin 2, and Interleukin 6 by T-lymphocytes, macrophages and neutrophils. These data demonstrate that pathophysiological levels of Substance P induce production of cytokines in all three cell populations tested. Interestingly, T-cells demonstrated the highest percentage of cells expressing all four cytokines. In contrast, macrophages and neutrophils produced the highest absolute levels of cytokines. The elucidation of mediating mechanisms of Substance P activation of leukocytes is crucial to the understanding of the cutaneous inflammatory cascade and involvement of the peripheral nervous system on the immune system. These findings suggest that Substance P participates in the complex network of mediators that regulate cutaneous inflammation and potentially the rate of wound healing.

Animals↗

Early chemokine cascades in murine cardiac grafts regulate T cell recruitment and progression of acute allograft rejection.

The identification of early inflammatory events after transplant in solid tissue organ grafts that may direct T cell recruitment and promote acute allograft rejection remain largely unknown. To better understand temporal aspects of early inflammatory events in vascularized organ grafts, we tested the intragraft expression of four different chemokines in heterotopically transplanted A/J (H-2(a)) and syngeneic heart grafts in C57BL/6 (H-2(b)) recipient mice from 1.5 to 48 h after transplant. Similar temporal expression patterns and equivalent levels of chemokine expression were observed in both syngeneic and allogeneic cardiac allografts during this time period. Expression of the neutrophil chemoattractant growth-related oncogene alpha (KC) was observed first and reached peak levels by 6 h after transplant and was followed by the monocyte/macrophage chemoattractant protein-1 (JE) and then macrophage inflammatory proteins 1beta and 1alpha. Administration of rabbit KC antiserum to allograft recipients within 30 min of cardiac transplantation attenuated downstream events including intra-allograft expression of the T cell chemoattractants IFN-gamma-inducible protein-10 and monokine induced by IFN-gamma, cellular infiltration into the allograft, and graft rejection. Similarly, depletion of recipient neutrophils at the time of transplantation significantly extended allograft survival from day 8 to 10 in control-treated recipients up to day 21 after transplant. These results indicate the induction of highly organized cascades of neutrophil and macrophage chemoattractants in cardiac grafts and support the proposal that early inflammatory events are required for optimal recruitment of T cells into allografts during the progression of acute rejection of cardiac allografts.

Acute Disease↗

The frequency of asymptomatic and electrically silent exercise-induced regional myocardial ischemia during first-pass radionuclide angiography with upright bicycle ergometry.

The presence of asymptomatic (silent) myocardial ischemia during provocative testing may limit the detection of ischemic heart disease, unless sensitive indicators of ischemia are utilized. Exercise ventricular function studies are well suited for ischemia detection since segmental dysfunction is an early pathophysiologic event in the ischemic cascade. In this study, we examined the rest and stress first-pass radionuclide angiographic studies of 104 patients with coronary artery disease and exercise-induced regional wall motion abnormalities. Asymptomatic ischemia was observed in 83 patients, while only 21 patients were symptomatic. Clinical variables were not different between the two groups, except for a higher frequency of a prior anginal history in the symptomatic group. The peak heart rate and pressure-rate product were significantly higher in the silent ischemia group, as these patients are not limited by symptoms. Wall motion scores, resting and exercise ejection fractions were similar in the two groups. The frequency of an ischemic electrocardiographic ST-segment response was low, and was not significantly different between groups. These data indicate that electrically and symptomatically silent myocardial ischemia are frequent occurrences with upright bicycle ergometry. Without adjunctive cardiac imaging, this mode of exercise may not be appropriate for the evaluation of ischemic heart disease.

Aged↗

Subcutaneous formalin produces centrifugal hyperalgesia at a non-injected site via the NMDA-nitric oxide cascade.

Previous work has demonstrated that pain facilitation can occur following injection of subcutaneous irritants, such as formalin. Such studies have focused on apparent pain facilitation induced at the site of irritant injection. Changes in processing of incoming pain information have typically been assumed to result from activation of neurocircuitry intrinsic to the spinal cord. The present series of studies have examined hyperalgesia exhibited at a site distant from the site of irritant injection and have begun to define the neurocircuitry and neuropharmacology underlying this pain enhancement. This work demonstrates that s.c. formalin injected into the dorsum of one hindpaw in rats produces prolonged hyperalgesia as measured by the tailflick test. Hyperalgesia is not mediated solely by circuitry intrinsic to the spinal cord, but rather involves activation of centrifugal pathways originating within the brain and descending to the spinal cord via pathway(s) outside of the dorsolateral funiculus. At the level of the spinal cord, this hyperalgesic state is mediated by an NMDA-nitric oxide cascade, since hyperalgesia can be abolished by administration of either an NMDA antagonist (APV) or a nitric oxide synthesis inhibitor (L-NAME).

2-Amino-5-phosphonovalerate↗

Equivalence testing of salbutamol dry powder inhalers: in vitro impaction results versus in vivo efficacy.

The aim of the study was to evaluate several impactors for in vitro equivalence testing of salbutamol with respect to efficacy and to define in vitro equivalence limits validated with in vivo efficacy data. The four impactors described in Supplement 2000 of the European Pharmacopoeia were used: Glass Impinger (GI), Metal Impinger (MI), Multistage Liquid Impinger (MSLI) and Andersen Cascade Impactor (ACI). Three salbutamol dry powder formulations with different fine particle doses (FPDs) were prepared and the aerodynamic particle size distribution was measured. For each impactor also the recovery was determined. The same three preparations were administered to 12 asthmatic patients in a randomized, placebo-controlled, four-way crossover study. Cumulative doses from 50 microg up to 400 microg were given. The FEV(1) was measured at baseline and 15 min after each dose. The in vitro results showed large differences between the FPDs of the three preparations with all impactors, whereas only small differences were observed between the four impactors. Since the recoveries of the MI and GI were low, in vitro equivalence testing should only be performed with the MSLI or ACI. The in vivo measurements did not show significant differences in efficacy between the three active preparations, even at the most discriminatory dose of 50 microg. It is concluded that in case there are no relevant differences between delivered dose, inhalation device and excipients, for salbutamol dry powder inhalers equivalence can be assumed when the 90% confidence interval for the FPD ratio of the test product and reference product is within 0.50-1.20 and each of the two products has a FPD (particles <6 microm) of at least 10 microg.

Adult↗

Lipopolysaccharide concentration and bone resorption in cholesteatoma.

HYPOTHESIS: There is a relationship between the local lipopolysaccharide (LPS) concentration in cholesteatoma and local bone resorption in chronic otitis media (COM) with cholesteatoma. BACKGROUND: During the past decade, it has become known that the recruitment of osteoclasts is the main causative factor that induces bone destruction in COM with cholesteatoma. Cellular inflammation factors like cytokines may trigger the osteoclast. Sequel to this, LPS is able to up-regulate cytokines. This makes it of interest to study whether the local LPS concentration is related to bone resorption in cholesteatoma. MATERIALS AND METHODS: Twenty-four cholesteatoma samples and control tissue from COM patients without cholesteatoma were collected. During surgery, the degree of bone resorption was established and classified. Retrospectively, the authors checked whether patients had chronic purulent otorrhea. LPS concentration of the tissue samples was measured by the limulus amebocyte lysate test. The one-way analysis of variance test was used to determine the relation between LPS concentration, otorrhea, and local bone resorption. RESULTS: A significantly higher concentration of LPS was measured in samples from patients with cholesteatoma with bone resorption and otorrhea compared with cholesteatoma without bone resorption and control tissue. There were no significant differences between the LPS levels of the different groups of patients with bone resorption. CONCLUSION: It is suggested that LPS is one of the first factors in the cascade of bone resorption in COM with cholesteatoma.

Bone Resorption↗

[Aspirin and heparin in the fibrinolytic treatment of acute myocardial infarction].

There is now extensive evidence of activation of platelet and the coagulation cascade with coronary thrombosis, and further activation with exogenous thrombolysis. Administration of aspirin and heparin has been shown to improve mortality when combined with thrombolytic therapy in acute myocardial infarction, probably by enhancing lysis and reducing subsequent reocclusion of infarct related artery. Most studies have evaluated the effect of aspirin or heparin in combination with streptokinase. These results can probably be extrapolated to rtPA, as it has much shorter, half live, and induces lower systemic lytic state. Although aspirin and heparin have been tested independently, they probably have a synergistic action post fibrinolysis. With current information it is mandatory to include aspirin in the treatment of AMI, with or with out thrombolytic treatment. Intravenous administration of heparin seems justified, specially if rtPA is used as fibrinolytic agent. Potent new drugs capable of inhibiting platelets an the coagulation cascade emerge as a promising future. Until their effect is clinically proven, aspirin and i.v. heparin should remain as adjunctive therapy to fibrinolytic treatment in AMI.

Aspirin↗

Intracellular phospho-protein staining techniques for flow cytometry: monitoring single cell signaling events.

BACKGROUND: Recent advances in intracellular staining techniques, cytometer technology, fluorescent reagents, and antibody production have expanded the number of intracellular antigens that can be analyzed by flow cytometry. Measurement of protein phosphorylation with phospho-specific antibodies has given insight into kinase signaling cascades. However, available techniques for phospho-epitope staining can differ greatly, making it necessary to understand the differences between the outcomes when such techniques are applied and to develop robust and reproducible methods of application. METHODS: Ten different cellular fixation and permeabilization techniques were tested for their ability to provide phospho-specific staining. Combinations of formaldehyde, methanol, ethanol, acetone, Triton X-100, and saponin were used as fixation and permeabilization reagents. Phospho-specific antibodies were labeled with Alexa Fluor dyes to provide multicolor analysis of different signaling events simultaneously within individual cells. RESULTS: Fixing cells with 1.5% formaldehyde followed by permeabilization in methanol gave optimal results for pERK, pp38, pJNK, pStat1, pStat5, and pStat6 staining. Alteration of formaldehyde fixation and methanol permeabilization times affected measurements of phosphorylation induction. Phospho-specific flow cytometric analyses correlated well with Western blotting, providing cross platform validation of the technique. CONCLUSIONS: Measuring phosphorylation events by flow cytometry provides a rapid and efficient way to measure kinase cascades in individual cells. Stability of phospho-epitopes in methanol allows long-term storage of samples prior to analysis. Multiple signaling cascades can be monitored simultaneously through the use of different fluorophore labels to determine specificity of ligands or inhibitors. Application of optimized techniques to heterogeneous cell types such as peripheral blood or murine splenocytes may allow signaling to be analyzed simultaneously in immune cell subsets.

Antibodies, Monoclonal↗

Activation of the Raf-1/MEK/ERK cascade by bile acids occurs via the epidermal growth factor receptor in primary rat hepatocytes.

Bile acids have been reported to activate several different cell signaling cascades in rat hepatocytes. However, the mechanism(s) of activation of these pathways have not been determined. This study aims to determine which bile acids activate the Raf-1/MEK/ERK cascade and the mechanism of activation of this pathway. Taurodeoxycholic acid (TDCA) stimulated (+235%) the phosphorylation of p(74) Raf-1 in a time (5 to 20 minutes) and concentration-dependent (10 to 100 micromol/L) manner. Raf-1 and ERK activities were both significantly increased by most bile acids tested. Deoxycholic acid (DCA) was the best activator of ERK (3.6-fold). A dominant negative Ras (N17) construct expressed in primary hepatocytes prevented the activation of ERK by DCA. The epidermal growth factor receptor (EGFR)-specific inhibitor (AG1478) significantly inhibited (approximately 81%) the activation of ERK by DCA. DCA rapidly (30 to 60 seconds) increased phosphorylation of the EGFR (approximately 2-fold) and Shc (approximately 4-fold). A dominant negative mutant of the EGFR (CD533) blocked the ability of DCA to activate ERK. In conclusion, these results show that DCA activates the Raf-1/MEK/ERK signaling cascade in primary hepatocytes primarily via an EGFR/Ras-dependent mechanism.

Animals↗

Update of the molecular basis of familial hypercholesterolemia in The Netherlands.

Autosomal-dominant hypercholesterolemia (ADH) has been identified as a major risk factor for coronary vascular disease (CVD) and is associated with mutations in the low-density lipoprotein receptor (LDLR) and the apolipoprotein B (APOB) gene. Since 1991 DNA samples from clinically diagnosed ADH patients have been routinely analyzed for the presence of LDLR and APOB gene mutations. As of 2001, 1,641 index patients (164 index patients per year) had been identified, while from 2001 onward a more sensitive, high-throughput system was used, resulting in the identification of 1,177 new index patients (average=294 index patients per year). Of these 1,177 index cases, 131 different causative genetic variants in the LDLR gene and six different causative mutations in the APOB gene were new for the Dutch population. Of these 131 mutations, 83 LDLR and four APOB gene mutations had not been reported before. The inclusion of all 2,818 index cases into the national screening program for familial hypercholesterolemia (FH) resulted in the identification of 7,079 relatives who carried a mutation that causes ADH. Screening of the LDLR and APOB genes in clinically diagnosed FH patients resulted in approximately 77% of the patients being identified as carriers of a causative mutation. The population of patients with ADH was divided into three genetically distinct groups: carriers of an LDLR mutation (FH), carriers of an APOB mutation (FDB), and non-LDLR/non-APOB patients (FH3). No differences were found with regard to untreated cholesterol levels, response to therapy, and onset of CVD. However, all groups were at an increased risk for CVD. Therefore, to ultimately identify all individuals with ADH, the identification of new genes and mutations in the genes that cause ADH is of crucial importance for the ongoing national program to identify patients with ADH by genetic cascade screening.

Adult↗

Antitumor effects of inhibitors of arachidonic acid cascade on experimentally induced intestinal tumors.

The antitumor action of inhibitors of cyclooxygenase (indomethacin) and lipoxygenase activity (nordihydroguaiaretic acid) of arachidonic acid cascade was investigated in the chemically induced large bowel tumors in Sprague-Dawley rats. Indomethacin treatment completely prevented the carcinogenic effect of methylazoxymethanol. Thus, no tumors were found in the 14 rat test group, compared with 13 of 14 tumor-bearing rats in the untreated control group. Although nordihydroguaiaretic acid treatment does not abolish prostaglandin synthesis, it does reduce the effect of the carcinogen and tumors were found in only five of 14 treated rats. From this study it can be postulated that not only is reduction in prostaglandin formation responsible for the inhibition of tumor growth, but also leukotrienes may play some role.

Animals↗