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Slivers of articular cartilage were stored in Ham's medium, plasma, polyvinyl pyrrolidone, and dimethyl sulphoxide at 0, -20, 4, and 38C. Survival was monitored by potassium determinations and autoradiography using S-35 and by matrix staining. Survival of 48 days was obtained in Ham's medium at 4C.
The purpose of this paper was to develop a tableting technology of barbital buffer as a standard diluent easy in use for complement fixation test (CFT). As starting point, barbital (veronal) buffer after Alton et al. [1] was assumed. Among 4 solubilizers polyvinyl pyrrolidone (PVP 10 000) was chosen, which provided a good solubility of the barbital in distilled water at 20 degrees C and it affected favourably the complement activity (C'). PVP 10 000 added to the components of barbital buffer at an amount of 0.275 per 10 tablets, in the form of solution for granulation, provided the required physical properties of the tablets. As compared with the barbital buffer after Alton et al. [1], the tablets produced affected favourably C' activity, decreased the range of spontaneous haemocyte lysis, and they did not effect CFT titers of two anti-Brucella abortus standard sera as well as 77 sera of cattle infected with brucellosis under natural conditions. The described physical and biological properties of the barbital buffer tablets with PVP addition indicate their usability as diluent for CFT. A standard diluent used in the form of tablets in all Poland's laboratories should provide a better reproducibility of CFT results in diagnostic examinations towards brucellosis as well as other infectious diseases in men and animals.
Spray drying of phenobarbital-polyvinyl pyrrolidone (PVP), phenobarbital-polyvinyl alcohol (PVA) and digoxin-PVP solutions yielded embeddings in the form of very fine powders. Depending on the drug-adjuvant ratio, the form in which the drug was embedded in the indifferent carriers was microcrystalline to radio-amorphous. In vitro studies showed that the dissolution of all the spray products was more rapid than that of the corresponding physical mixtures, and that the resulting solutions of the respective drugs were always oversaturated. The oversaturated solutions obtained from embeddings containing the amorphous forms of the difficulty soluble drugs were relatively stable. PVP inhibited the crystallization of phenobarbital to a greater extent than PVA, and led to a higher oversaturation of the drug in the resulting solutions. The in vitro release of digoxin was significantly more rapid from PVP embeddings (and tablets made from them) than from products containing digoxin in crystalline form.
Diphenylhydantoin (DPH) depresses serum IgA and IgM concentrations and polyvinyl pyrrolidone (PVP) clearance in mice.
Nefiracetam (N-(2,6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl) acetamide DM-9384, CAS 77191-36-7), a pyrrolidone (cyclic GABA) derivative, is a newly developed cognition-enhancing (nootropic) agent. In the present study, the effects of nefiracetam on cerebral monoamine metabolism in rats after microsphere-induced cerebral embolism have been examined. For cerebral embolization, microspheres were injected into the left internal carotid artery. Nefiracetam (3, 10 and 30 mg/kg p.o.) was administered daily to the animals for 13 days from the 9th day after the operation. The levels of DA, DOPAC and HVA in the control (embolism-induced, but untreated) group were significantly decreased compared with those of the normal (non-operated) group. In animals treated with nefiracetam (3 mg/kg p.o.), these monoamine levels were higher than controls in the cortex and hippocampus, whereas they were not significantly changed in the striatum. 5-HT contents in the control group significantly decreased from normal levels in the cortex and hippocampus, on which nefiracetam at various doses had no effect. The levels of 5-HIAA in the control group also decreased, which were, however, significantly increased by 3 mg/kg of nefiracetam. The results suggest that nefiracetam has improving actions on the dysfunction of the dopaminergic and serotonergic systems induced by cerebral embolism.
Three inhibitors of calcium-dependent cyclic adenosine 3'5'-monophosphate (cAMP) dependent phosphodiesterase IV (PDE IV) were evaluated for their effects on lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF) production in vitro and in vivo and for their ability to protect mice from LPS-induced lethality in D-galactosamine (D-gal) sensitized mice. In vitro, on LPS-stimulated murine peritoneal macrophages (PEM), BRL 61063 (1,3-di(cyclopropylmethyl)-8-aminoxanthine) and rolipram (4-(3-cyclopentyloxy-4-methoxyphenyl)-2-pyrrolidone) had similar TNF inhibitory activity with an IC50 ranging from 0.1 to 0.5 microM. Pentoxifylline (PTX), (3,7-dimethyl-1-(5-oxohexyl)xanthine) was less potent with an IC50 = 100 microM. In vivo, there was a rank order potency on serum TNF levels in LPS challenged D-gal sensitized mice. BRL 61063 inhibited TNF production with an ID50 of 0.1 mg/kg, rolipram at 1 mg/kg, and PTX at 200 mg/kg. Thus, BRL 61063 is 2,000 times more potent than PTX in reducing TNF serum levels in this model. Interestingly, TNF is implicated as having a central pathogenic role in the LPS/D-gal model, since survival of animals correlated directly with reduction of serum TNF levels for all three compounds tested. It is proposed that potent inhibitors of TNF may have therapeutic activity in disease states where TNF appears to play a role in the pathogenesis of the disease.
Infection of susceptible mice with murine cytomegalovirus (MCMV) induces persistent inflammation, and the production of autoantibodies reactive with large numbers of proteins from all major organs. However the roles of polyclonal B-cell activation, autoreactive T-helper cells and host-virus cross-reactions in these phenomena have not been evaluated. The present study reveals six- to 20-fold increases in serum immunoglobulin levels in MCMV-infected BALB/c and CBA mice, with IgG3 and IgG2b most affected. Titres of antibodies reactive with autologous tissues and ovalbumin (OVA) also increased following MCMV infection, whilst responses to a synthetic antigen [polyvinyl pyrrolidone (PVP)] were unaffected or depressed. IgG2a was the isotype most affected in responses to OVA, MCMV antigens and autologous tissues, suggesting interferon-gamma (IFN-gamma) may contribute to responses induced in the presence of the relevant antigen. Increases in total and antigen-specific immunoglobulin levels were CD4 dependent, as they were reduced in infected mice depleted of these cells with anti-CD4 antibodies. Serological changes were preceded by B-cell expansion and activation evident from increased cell yields, frequencies of cells releasing immunoglobulin and proliferation of T-depleted spleen and lymph node preparations. Numbers of mature B cells and macrophages increased in the lymph nodes, but B-1a (CD5+ Ig+) cell counts remained low. Alterations in the B-cell phenotypic profiles were more complex in the spleen, but correction for increased cell yields revealed increases in some subpopulations.
Piracetam, 1-pyrrolidone acetamid, was tested in 40 chronic alcoholics with a more or less marked psycho-organic syndrome by means of psychological tests. It was a double-blind-cross-over study. Statistical analysis of the results showed that Piracetam improves the energo-functional capacity of the cortex i.e. the basal functions of the cortical cells such as activating capacity, vital dynamic, flexibility, intellectual reactivity and stress tolerance. Apart from the overall improvement we also observed an improvement of specific cerebral performances which is however unimportant in comparison with the greneralized effect.
Stabilizing effect of several commonly used cryoprotectants, namely lactose, sucrose, and polyvinyl-pyrrolidone (PVP), on recombinant alpha 1-antitrypsin (rAAT) were studied. A solution of rAAT in a phosphate/citrate buffer (pH 7.0) was made with and without a given cryoprotectant and filled into small vials. The vials were frozen on shelf, at -40 degrees C in a lyophilizer. At the end of the freezing cycle, half of the batch was thawed at ambient temperature and the other half was continued to the completion of lyophilization. Sample vials taken before freezing, after thawing, and after lyophilization were analyzed for total rAAT protein, monomeric content, and elastase-inhibitory activity. Results indicated that neither freeze-and-thaw nor lyophilization caused any damage to rAAT, contrary to what was generally believed. The control formulation (i.e., without a cryoprotectant) performed as good as those containing cryoprotectants. Freezing rates and protein concentration in formulation did not influence the stability of rAAT either. Lyophilized rAAT samples retained the activity and purity during the 12 month stability period, at room temperature and 2-8 degrees C.
It was found that 48 hour cultures of Actinobacillus pleuropneumoniae secreted proteases into the medium. Electrophoresis in polyacrylamide gels (10%) copolymerized with porcine gelatin (0.1%), of the 70% (NH4)2SO4 precipitate from the culture supernatants, displayed protease activities of different molecular weights: > 200, 200, 90, 80, 70 and 50 kDa. They had activity over a broad range of pHs (4-8), with an optimal pH of 6-7. All were inhibited by 10 mM EDTA, and reactivated by 10 mM calcium. They were stable at -20 degrees C for more than a month. The proteases also degraded porcine IgA and porcine, human, and bovine hemoglobin, although they appeared to be less active against the hemoglobins. The IgA was totally cleaved in 48 h, using supernatants concentrated with polyvinyl pyrrolidone or the 70% (NH4)2SO4. Extracellular proteases could play a role in virulence.
The effect of mangiferin, a tetrahydroxy pyrrolidone saponin extracted from the leaves of mango (Mangifera indica), against herpes simplex virus type 2 (HSV-2) in vitro was studied. The 50% effective concentration (EC50) of it against HSV-2 plaque formation in HeLa cells was 111.7 micrograms.ml-1, and the concentrations of 33 and 80 micrograms.ml-1 reduced the virus replicative yields by 90% (EC90) and 99% (EC99), respectively. The therapeutic index (IC50/EC50) was 8.1. Mangiferin did not directly inactivate HSV-2. The results of the drug addition and removal tests suggest that mangiferin inhibits the late event in HSV-2 replication.
To estimate the germ-preserving effect of 15 percent disodium-calcium-ethylene-diamine-tetraacetate, 1.8 percent boric acid, 20 percent dimethyl sulfoxide and 3 solutions containing 0.001 percent merthiolate and 15 percent glycerin, 2 percent ethylene-diamine-tetraacetic acid and 15 percent glycerin, and 30 percent NaCl and 3 percent polyvinyl pyrrolidone respectively, comparative investigations were conducted in 4 series comprising a total of 400 urine samples. Boric acid, which is very easy to use, proved the most effective. After 24-h storage at room temperature of boric-acid-preserved urine samples with bacterial counts of over 10-4 per ml, the results were false-negative in 2-4 percent; after 48 h the rate was 6-8 percent and after 72 h nearly 10 percent. There were no false-positive results.
With a modified microcytotoxicity assay, the effects of lymphocytes from normal volunteers and from patients with a variety of solid malignant tumors were tested in vitro against both normal and neoplastic target cells. The study was divided into three sequential time phases in each of which a different method of lymphocyte separation was used. Lymphocytes were separated by a Ludox-polyvinyl-pyrrolidone technique in the first phase, by nylon wool filtration in the second phase, and by a Ficoll-Hypaque technique in the third phase of the study. In the first two phases of the study, lymphocytes from both normal volunteers and cancer patients were frequently toxic on both tumor cells and fibroblasts. In the last phase of the study types of target cells. Cancer patient lymphocytes were more frequently toxic on tumor cells but no more frequently toxic on fibroblasts than were normal lymphocytes. The different results obtained in the last phase of the study cannot be attributed solely to the different method of lymphocyte separation, since other factors, such as better growth status of the target cells and greater facility in performing the assays, might also be responsible. Results of the last phase of the study raise the possibility that both specific and nospecific reactions may contribute to the toxicity observed in this laboratory with cancer patient lymphocytes tested against tumor cells. It has not yet been possible to reduce the level or frequency of the nonspecific reactions to such a degree that the microcytotoxicity assay can be used clinically to document clearly or to follow the putative tumor-specific immunity of individual cancer patients.
Some new cyclic analogues of baclofen have been prepared and characterized, starting from 4-(4-chlorophenyl)-pyrrolidone. When tested in comparison with the parent compound, they exhibited only a moderate muscle relaxant activity.
The paper deals with the therapeutic use of contact lenses made from a new highly hydrated material developed in the Institute of Macromolecular Chemistry in Prague. Contact lenses made from a meshed copolymer of n-vinyl pyrrolidone with acetoxyethyl meta-acrylate were applied to a group of 83 patients--a total of 87 eyes. A favourable therapeutic effect was achieved in all groups of patients--in simple traumatic erosions, superficial keratopathies, relapsing erosions, bullous keratopathies, corrosion of cornea, for mechanical protection of epithelization and in persisting ulcerations. In 71 eyes (82%) the contact lens was removed after the therapeutic effect was achieved, in 4 (5%) treatment still proceeds. In the remaining patients treatment was discontinued on account of complications, persistence of the pathological finding and frequent losses of contact lenses. In the group there was no case of complicating keratoconjunctivitis. Progressing vascularization was detected in three cases in the group with persisting ulcerations. The authors did not observe development of corneal vascularization in conjunction with application of the lens. Transient corneal oedema was revealed in the group of relapsing erosions in 6 (40%) patients and in the group of persisting superficial keratopathies in 4 (31%). The rare occurrence of inflammatory complications can be explained by the sterile application of contact lenses for the necessary length of time, the local administration of antibiotics while the defect persisted and frequent check-up examinations. Contact lenses made from the described material proved useful for therapeutic application.
The metabolic pathway of DL-rolipram was studied in two animal species and in man. Metabolites were isolated from rat, rhesus monkey, and from human urine by preparative HPLC and identified by MS and NMR analysis. In total, the structures of 7 degradation products could be elucidated. Rolipram was metabolized by ether cleavage at the methoxy and cyclopentyloxy groups and by hydroxylation in positions 2 or 3 of the cyclopentyloxy ring followed by sulphation. Additionally, but exclusively in man, the 5-position of the pyrrolidone ring was hydroxylated.
Thirty-five newborn foals were assigned to 1 of 3 groups and treated with 0.9% NaCl solution (saline; group 1; n = 12), oxytetracycline (44 mg/kg of body weight; group 2; n = 12), or 2-pyrrolidone (oxytetracycline vehicle; group 3; n = 11) in saline solution during the first 36 hours after birth. Serum biochemical analyses were performed on samples obtained from group-1 and group-2 foals before treatment and 24 and 96 hours after treatment. Lateral to medial radiographic views of the forelimbs were obtained before treatment and 24 and 96 hours after treatment in all foals. Metacarpophalangeal and distal interphalangeal joint angles were measured from the radiographic images. Significant changes in blood chemistry values, other than those typically observed in newborn foals, were not detected. A significant decrease in mean metacarpophalangeal joint angle was observed in foals 24 hours after treatment with oxytetracycline, compared with that in foals of groups 1 and 3. The mean metacarpophalangeal joint angle returned to pretreatment values by 96 hours. Oxytetracycline appears to be an effective method for obtaining a short-term moderate decrease in metacarpophalangeal joint angle in newborn foals.
CD8+ T cells from naturally infected disease-resistant sooty mangabeys (Cercocebus atys) secrete a soluble factor which inhibits the in vitro replication of the simian immunodeficiency virus (SIV). To gain further insight on the mechanism(s) involved, CD8+ effector T cells and target cells from sooty mangabeys were immortalized and cloned. The target cells were then stably transfected with an SIV-LTR-CAT construct or with the parental CAT plasmid as a control. A quantitative RT-PCR method, providing the necessary sensitivity, was developed to monitor the influence of the cloned CD8+ T cells on the CATmRNA contained in the target cells. It could be demonstrated that a soluble factor was secreted by the cloned CD8+ T cells from sooty mangabeys, which appeared to regulate CATmRNA activity in a dose-dependent and reversible manner. Kinetic experiments showed that the CATmRNA transcriptional activity was initially augmented at 30 min postcoculture and was followed by a marked decrease in transcriptional activity after a few hours. This immediate early response could be mitigated utilizing H7, Calmodulin, or PDTC (a pyrrolidone derivative of dithiocarbamate), suggesting that the pathway was protein kinase-dependent and that the NF-kappa B site may be involved. The inhibitory effect could also be overcome using a protein synthesis inhibitor, suggesting that protein synthesis was needed to negatively regulate CATmRNA activity and hence SIV promoter activity.