Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P30536 (PBS)
 9,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The steady-state transmembrane potentials of P815 mastocytoma cells were recorded when the cells were bathed in salines of different compositions. In the normal growth medium (RPMI 1640 with added fetal calf serum) the mean membrane potential was -8.7 mV (SEM +/- 0.4, n = 22). A family of Tris-buffered salines (TBS), modeled from Dulbecco's modified PBS (289 mosmol, 169 milliionic strength units, pH 7.5), having different K+ and different C1- concentrations, were designed and used to bathe the tumor cells. All of the TBS solutions had constant, but reduced levels of ionized Ca2+. In the absence of external C1-, an increase of external K+ from 2 to 20 mM results in a 5.7 mV depolarization. In the presence of external C1- the same increase in external K+ results in a 2.1 mV depolarization. The presence of 145 mM C1- resulted in a steady-state depolarization (for either level of K) of about 50%. One explanation for these results would be the presence of an inward-going active C1- transport.
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PMID:Effects of potassium and chloride on the membrane potentials of P815 mastocytoma tumor cells. 681 35

Quantitative and morphological analyses (in SEM) of blood platelets collected from the left and right ventricles of the rat heart in the course of experimental lung emphysema were done. Platelet aggregation index was estimated, too. Emphysema was induced by a single intratracheal instillation of papain solution in a dose of 20 mg/kg b.w/1 ml PBS. The animals were sacrificed after 2 and 24 hours and 7, 14, 28 days later. Within 24 hours of the experiment a slight decrease was observed in the number of platelets in the blood collected from the left ventricle compared to the right one as well as to control animals. Also a reduction in platelet aggregation coefficient value was noted. However, in the later period of emphysema progression (after 7th day), a statistically significant increase was found in the number of blood platelets in the left ventricle. A relation was noted between quantitative changes of blood platelets and emphysema progression evaluated morphometrically. The ultrastructural examinations in SEM suggest the occurrence of platelet satellitosis in animals intratracheally injected with papain solution. The present results indicate the possibility of a significant contribution of blood platelets to the pathogenesis of experimental lung emphysema.
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PMID:Blood platelets in experimental lung emphysema. Comparative analysis of the number and aggregation abilities of platelets in left and right ventricular blood of the heart. 769 33

The effects of low level laser (LLL) irradiation on the proliferation of human buccal fibroblasts were studied. A standardized LLL set-up was developed (812 nm, 4.5 +/- 0.5 mW/cm2). Cultures in petridishes were divided into eight groups (1 group served as control). On day 6 after seeding, routine growth medium was replaced with PBS for 1/2 hour. At the beginning of this period, LLL irradiation was performed for 0, 1, 3, 10, 32, 100, 316, or 1,000 seconds, respectively--corresponding to the radiant exposures 0, 4.5, 13.5, 45, 144, 450, 1,422, 4,500 mJ/cm2. Subsequently the cells received 3H-dT in fresh medium for 16 hours DNA-incorporation. Scintillations from tritium and total protein concentration per culture dish were determined. The individual 3H-cpm/protein-concentration ratios were calculated in % of control. Three experiments were performed (N = 151). Following LLL exposure the 3H-cpm/protein ratio was increased with maximum cpm/protein ratio (132.5% +/- 10.6% SEM) in the group receiving 450 mJ/cm2 (P < 0.03 nonparametric Kruskal Wallis one-way ANOVA-test). This study demonstrated an increased incorporation on tritiated thymidine in cultured human oral fibroblasts following LLL exposure and suggests that LLL irradiation can induce increased DNA synthesis.
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PMID:Effect of low level diode laser irradiation of human oral mucosa fibroblasts in vitro. 807 84

Four experiments determined the kinetics of in vitro maturation and fertilization of cat oocytes and the effects of prolonged cold storage of ovaries before oocyte recovery on in vitro maturation/in vitro fertilization (IVM/IVF) success. Domestic cat ovaries were collected at ovariohysterectomy and stored at 4 degrees C in PBS until oocyte recovery and culture in Eagle's minimal essential medium (EMEM) containing FSH, LH, oestradiol and BSA for maturation. In Expt 1, meiotic maturation was assessed at 0, 12, 24, 38 and 48 h of culture. After 24 h, > 61% of oocytes were in telophase I or metaphase II. In Expt 2, oocytes were recovered from ovaries stored for 24, 48 or 72 h and cultured in EMEM for 24 h. There was no difference among groups (P > 0.05) in the ability to achieve nuclear maturation (mean +/- SEM, 57.1 +/- 5.3%, 60.4 +/- 5.4%, 55.4 +/- 15.1% for 24, 48 and 72 h, respectively). Fertilization and embryo development after insemination at 16, 24, 32, 40 and 48 h of culture were examined in Expt 3. Of 98 oocytes inseminated at 32 h, 69% cleaved, 59% developed into morulae and 13% into blastocysts, more (P < 0.05) than those oocytes inseminated at earlier and later times. Development to blastocysts occurred after insemination at 16 (1.2%), 24 (9.1%) and 32 (13.3%) h of culture, but not after insemination at 40 or 48 h. Expt 4 involved cold storage of ovaries for 24, 48 or 72 h before oocyte recovery and insemination at 32 h of culture (the optimal time measured in Expt 3). Compared with storage for 24 h, fertilization success was lower (P < 0.05) in the 48 and 72 h groups, and, although 9.1% of inseminated oocytes from the 24 h storage group developed to blastocysts, none (P < 0.05) achieved this stage after 48 or 72 h of storage. These results indicate that domestic cat oocytes reach nuclear maturity by 24 h in culture and can be fertilized and develop to blastocysts optimally after insemination at 32 h. Oocytes recovered from ovaries stored at 4 degrees C for up to 72 h are capable of reaching telophase I or metaphase II in vitro. However, only oocytes stored within the ovary for 24 h produce blastocysts, indicating that the ability to achieve nuclear maturation is an inadequate indicator of fertilization and developmental competence.
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PMID:Development to blastocysts of domestic cat oocytes matured and fertilized in vitro after prolonged cold storage. 866 38

The cysteinyl leukotriene LTE4 has been shown to induce airway eosinophilia in asthmatics in vivo. This phenomenon has not yet been reported for LTD4. Hence, we examined the effect of inhaled LTD4 and a control bronchoconstrictor agent, methacholine, on cell differentials in hypertonic saline-induced whole sputum samples of 12 nonsmoking atopic asthmatic subjects (three women, nine men; 21 to 29 yr of age; FEV1, 74 to 120% pred; PC20FEV1 methacholine < 9.6 mg/ml). The study had a cross-over, placebo-controlled design consisting of 4 d separated by > or = 1 wk. On each randomized study day, the subjects inhaled five serial doses of either LTD4 (mean cumulative concentration: 95.7 microM) or methacholine (mean cumulative concentration: 542 mM) or five doses of their respective diluents (PBS/ethanol or PBS). The airway response was measured by FEV1, followed by sputum induction with 4.5% NaCl, 4 h postchallenge. Inflammatory cells (> or = 250) were counted twice on coded cytospins and expressed as percentages of nonsquamous cells. There was no significant difference in the maximal percent fall in FEV1 from baseline between LTD4 (mean +/- SEM, 49.5 +/- 4.4% fall) and methacholine (mean +/- SEM, 55.9 +/- 3.4% fall) (p = 0.11). LTD4 induced a significant increase in the percentage of sputum eosinophils as compared with its diluent (mean +/- SD, 26.6 +/- 21.3% and 10.2 +/- 8.8%, respectively; p = 0.025), whereas a similar trend for methacholine failed to reach significance (mean +/- SD, 19.1 +/- 22.9% and 7.8 +/- 5.8%, respectively; p = 0.11). There was no significant difference in the changes in the percentage of sputum eosinophils between LTD4 and methacholine (mean difference +/- SD, 7.5 +/- 12.5% eosinophils; p = 0.09). We conclude that LTD4 induces eosinophilia in sputum of asthmatic subjects 4 h after inhalation. Our data suggest that LTD4 recruits eosinophils into the airways of asthmatics in vivo, possibly by virtue of direct or indirect chemotactic properties, whereas an additional effect of vigourous airway narrowing per se cannot be excluded.
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PMID:The effect of inhaled leukotriene D4 and methacholine on sputum cell differentials in asthma. 910 62

In this study, the hydraulic conductivity (Lp), Me2SO permeability (PMe2SO), and the reflection coefficients (sigma) and their activation energies were determined for Metaphase II (MII) mouse oocytes by exposing them to 1.5 M Me2SO at temperatures of 30, 20, 10, 3, 0, and -3 degrees C. These data were then used to calculate the intracellular concentration of Me2SO at given temperatures. Individual oocytes were immobilized using a holding pipette in 5 microliters of an isosmotic PBS solution and perfused with precooled or prewarmed 1.5 M Me2SO solutions. Oocyte images were video recorded. The cell volume changes were calculated from the measurement of the diameter of the oocytes, assuming a spherical shape. The initial volume of the oocytes in the isoosmotic solution was considered 100%, and relative changes in the volume of the oocytes after exposure to the Me2SO were plotted against time. Mean (means +/- SEM) Lp values in the presence of Me2SO were (LpMe2SO) at 30, 20, 10, 3, 0 and -3 degrees C were determined to be 1.07 +/- 0.03, 0.40 +/- 0.02, 0.18 +/- 0.01, 7.60 x 10(-2) +/- 0.60 x 10(-2), 5.29 x 10(-2) +/- 0.40 x 10(-2), and 3.69 x 10(-2) +/- 0.30 x 10(-2) microns/min/atm, respectively. The PMe2SO values were 3.69 x 10(-3) +/- 0.3 x 10(-3), 1.07 x 10(-3) +/- 0.1 x 10(-3), 2.75 x 10(-4), +/- 0.15 x 10(-4), 7.83 x 10(-5) +/- 0.50 x 10(-5), 5.24 x 10(-5) +/- 0.50 x 10(-5), and 3.69 x 10(-5) +/- 0.40 x 10(-5) cm/min, respectively. The sigma values were 0.70 +/- 0.03, 0.77 +/- 0.04, 0.81 +/- 0.06, 0.91 +/- 0.05, 0.97 +/- 0.03, and 1 +/- 0.04, respectively. The estimated activation energies (Ea) for LpMe2SO, and PMe2SO, and sigma were 16.39, 23.24, and -1.75 Kcal/mol, respectively. These data may provide the fundamental basis for the development of more optimal cryopreservation protocols for MII mouse oocytes.
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PMID:Membrane permeability characteristics of metaphase II mouse oocytes at various temperatures in the presence of Me2SO. 965 33

In previous studies it has been demonstrated that frozen human vaginal mucosa can be used as a model of buccal mucosa for in vitro permeability studies on a variety of chemical compounds, including drugs. However, most of the latter studies have, for the sake of convenience, been conducted at room temperature (+/- 20 degrees C). The objective of the present study was to determine the effects of increased temperature on steady state flux rates of water through vaginal mucosa. Specimens of clinically healthy human vaginal mucosa were obtained from excess tissue removed during a vaginal hysterectomy from a single patient, snap-frozen in liquid nitrogen at -85 degrees C and banked for 8 months. After thawing in PBS buffer, seven sections from the vaginal mucosa were mounted in flow-through diffusion cells (exposed area 0.039 cm2) and their permeability to tritiated water determined using a continuous flow-through perfusion system at temperatures of 25 degrees, 30 degrees and 37 degrees C. Permeability experiments were performed in triplicate at each temperature setting. Specimens were examined histologically before and after permeability experiments. Mean water flux rates at steady state (16-24 h) were found to be 1760 +/- 22 SEM, 2623 +/- 63 SEM and 4155 +/- 70 SEM cpm. cm-2.min-1, at temperatures of 25 degrees, 30 degrees and 37 degrees C, respectively. A linear regression analysis and plot (r2 = 0.99) displayed a slope of 200 +/- 13 SEM cpm. cm-2.min-1/degree C. The results of this study clearly demonstrated the temperature-dependency of flux rates of water across vaginal mucosa, and this should be taken into account whenever the in vitro vaginal/buccal model is used at room temperature for predicting in vivo buccal drug absorption kinetics.
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PMID:Effect of temperature on permeability of mucosa to water. 1051 20

Microspheres of a polyelectrolyte complex hydrogel were prepared from chitosan and xanthan after interaction between the two polyionic polymers. Their biodegradation was studied vs. chitosan. Simulated gastric fluid (SGF, pH 1.2) and intestinal fluid (SIF, pH 7.5) both as biodegradation media and phosphate buffered saline (PBS, pH 7.4) as a negative control were used. The degradation studies were performed at 37 degrees C at 240 rpm permanent stirring to mimic the physiologic conditions. High performance liquid chromatography (HPLC) was carried out to quantify the chitosan degradation products using glucosamine (GA) and N-acetyl-D-glucosamine (N-Ac-GA) as references. The peaks area integration method was used to determine the amount of each degradation product as a function of incubation time in the media. The effect of the media on the morphological structure of microspheres was assessed by scanning electron microscopy. From HPLC studies, it appeared that in SGF and SIF the major degradation products were glucosamine (GA) and N-acetyl-D-glucosamine (NAc-GA). In the first 15 days, oligochitosan fractions were released from the complex, whereas N-acetyl-D-glucosamine was detected in the media after this period. The degradation kinetics were assessed by the measurement of the cumulative degradation products, which showed faster degradation of chitosan than the complex in SGF and SIF. SEM micrographs showed an enhancement of microsphere porosity as a function of incubation time in the simulated physiological media. Our results suggest a better control of the degradation kinetics when chitosan is complexed to xanthan.
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PMID:Study of biodegradation behavior of chitosan-xanthan microspheres in simulated physiological media. 1098 9

A new family of alternate poly(ester-anhydrides) containing aliphatic and aromatic diacids were synthesized. The dicarboxylic acids were obtained by derivatization of p-hydroxy benzoic acid at the hydroxy terminus with cyclic anhydride (adipic anhydride and succinic anhydride) and subsequently polymerized via the corresponding mixed anhydrides by melt polycondensation. DSC traces revealed that the polymers had low Tg (< 40 degrees C) and no crystallinity. The static contact angle measurements indicated that the poly(ester-anhydrides) were more hydrophobic than poly(D,L-lactide) and poly(adipic anhydride). In vitro degradation of the polymers was also investigated in pH 7.4 PBS at 37 degrees C. It was found that degradation rate of the poly(ester-anhydrides) increased with p-carboxy phenyl adipic monoester (CPA) content in the polymers and the degradation duration could be adjusted from ca. 20 days to ca. 2 months. Erosion curve of poly(p-carboxy phenyl adipic monoester anhydride) (PCPA) was characterized by a linear region of weight loss at nearly constant rate in the first 7 days (ca. 80% of weight loss) followed by a gradual decrease region. IR and SEM analysis showed that significant erosion of PCPA occurred in the outer layer and no apparent erosion could be seen in the inner layer of the degrading sample after 7-day degradation. The poly(ester-anhydrides) may be used as either anti-infective polymeric prodrugs or matrices for drug delivery.
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PMID:Synthesis, characterization and in vitro degradation of a new family of alternate poly(ester-anhydrides) based on aliphatic and aromatic diacids. 1119 96

Our group recently demonstrated that autoimmune T cells directed against central nervous system-associated myelin antigens protect neurons from secondary degeneration. We further showed that the synthetic peptide copolymer 1 (Cop-1), known to suppress experimental autoimmune encephalomyelitis, can be safely substituted for the natural myelin antigen in both passive and active immunization for neuroprotection of the injured optic nerve. Here we attempted to determine whether similar immunizations are protective from retinal ganglion cell loss resulting from a direct biochemical insult caused, for example, by glutamate (a major mediator of degeneration in acute and chronic optic nerve insults) and in a rat model of ocular hypertension. Passive immunization with T cells reactive to myelin basic protein or active immunization with myelin oligodendrocyte glycoprotein-derived peptide, although neuroprotective after optic nerve injury, was ineffective against glutamate toxicity in mice and rats. In contrast, the number of surviving retinal ganglion cells per square millimeter in glutamate-injected retinas was significantly larger in mice immunized 10 days previously with Cop-1 emulsified in complete Freund's adjuvant than in mice injected with PBS in the same adjuvant (2,133 +/- 270 and 1,329 +/- 121, respectively, mean +/- SEM; P < 0.02). A similar pattern was observed when mice were immunized on the day of glutamate injection (1,777 +/- 101 compared with 1,414 +/- 36; P < 0.05), but not when they were immunized 48 h later. These findings suggest that protection from glutamate toxicity requires reinforcement of the immune system by antigens that are different from those associated with myelin. The use of Cop-1 apparently circumvents this antigen specificity barrier. In the rat ocular hypertension model, which simulates glaucoma, immunization with Cop-1 significantly reduced the retinal ganglion cell loss from 27.8% +/- 6.8% to 4.3% +/- 1.6%, without affecting the intraocular pressure. This study may point the way to a therapy for glaucoma, a neurodegenerative disease of the optic nerve often associated with increased intraocular pressure, as well as for acute and chronic degenerative disorders in which glutamate is a prominent participant.
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PMID:Vaccination for protection of retinal ganglion cells against death from glutamate cytotoxicity and ocular hypertension: implications for glaucoma. 1124 90


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