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1.
Immunooncol Technol ; 20: 100397, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37876518

ABSTRACT

The Association for Cancer Immunotherapy (CIMT) celebrated the 20th anniversary of the CIMT Annual Meeting. CIMT2023 was held 3-5 May 2023 in Mainz, Germany. 1051 academic and clinical professionals from over 30 countries attended the meeting and discussed the latest advances in cancer immunology and immunotherapy research. This report summarizes the highlights of CIMT2023.

2.
J Control Release ; 363: 1-11, 2023 11.
Article in English | MEDLINE | ID: mdl-37714435

ABSTRACT

Different types of ibuprofen-loaded, poly (D,L lactic-co-glycolic acid) (PLGA)-based implants were prepared by 3D printing (Droplet Deposition Modeling). The theoretical filling density of the mesh-shaped implants was varied from 10 to 100%. Drug release was measured in agarose gels and in well agitated phosphate buffer pH 7.4. The key properties of the implants (and dynamic changes thereof upon exposure to the release media) were monitored using gravimetric measurements, optical microscopy, Differential Scanning Calorimetry, Gel Permeation Chromatography, and Scanning Electron Microscopy. Interestingly, drug release was similar for implants with 10 and 30% filling density, irrespective of the experimental set-up. In contrast, implants with 100% filling density showed slower release kinetics, and the shape of the release curve was altered in agarose gels. These observations could be explained by the existence (or absence) of a continuous aqueous phase between the polymeric filaments and the "orchestrating role" of substantial system swelling for the control of drug release. At lower filling densities, it is sufficient for the drug to be released from a single filament. In contrast, at high filling densities, the ensemble of filaments acts as a much larger (more or less homogeneous) polymeric matrix, and the average diffusion pathway to be overcome by the drug is much longer. Agarose gel (mimicking living tissue) hinders substantial PLGA swelling and delays the onset of the final rapid drug release phase. This improved mechanistic understanding of the control of drug release from PLGA-based 3D printed implants can help to facilitate the optimization of this type of advanced drug delivery systems.


Subject(s)
Lactic Acid , Polyglycolic Acid , Polylactic Acid-Polyglycolic Acid Copolymer/chemistry , Drug Liberation , Polyglycolic Acid/chemistry , Sepharose , Lactic Acid/chemistry , Gels , Printing, Three-Dimensional , Drug Implants
3.
Nature ; 613(7944): 503-507, 2023 01.
Article in English | MEDLINE | ID: mdl-36653569

ABSTRACT

The Greenland Ice Sheet has a central role in the global climate system owing to its size, radiative effects and freshwater storage, and as a potential tipping point1. Weather stations show that the coastal regions are warming2, but the imprint of global warming in the central part of the ice sheet is unclear, owing to missing long-term observations. Current ice-core-based temperature reconstructions3-5 are ambiguous with respect to isolating global warming signatures from natural variability, because they are too noisy and do not include the most recent decades. By systematically redrilling ice cores, we created a high-quality reconstruction of central and north Greenland temperatures from AD 1000 until 2011. Here we show that the warming in the recent reconstructed decade exceeds the range of the pre-industrial temperature variability in the past millennium with virtual certainty (P < 0.001) and is on average 1.5 ± 0.4 degrees Celsius (1 standard error) warmer than the twentieth century. Our findings suggest that these exceptional temperatures arise from the superposition of natural variability with a long-term warming trend, apparent since AD 1800. The disproportionate warming is accompanied by enhanced Greenland meltwater run-off, implying that anthropogenic influence has also arrived in central and north Greenland, which might further accelerate the overall Greenland mass loss.


Subject(s)
Climate , Global Warming , Temperature , Global Warming/statistics & numerical data , Greenland , Ice Cover , Human Activities/trends , Water Movements , Freezing
4.
J Control Release ; 353: 864-874, 2023 01.
Article in English | MEDLINE | ID: mdl-36464064

ABSTRACT

3D Printing offers a considerable potential for personalized medicines. This is especially true for customized biodegradable implants, matching the specific needs of each patient. Poly(lactic-co-glycolic acid) (PLGA) is frequently used as matrix former in biodegradable implants. However, yet relatively little is known on the technologies, which can be used for the 3D printing of PLGA implants. The aim of this study was to compare: (i) Arburg Plastic Freeforming Droplet Deposition Modeling (APF DDM), and (ii) Fused Deposition Modeling (FDM) to print mesh-shaped, ibuprofen-loaded PLGA implants. During APF DDM, individual drug-polymer droplets are deposited, fusing together to form filaments, which build up the implants. During FDM, continuous drug-polymer filaments are deposited to form the meshes. The implants were thoroughly characterized before and after exposure to phosphate buffer pH 7.4 using optical and scanning electron microscopy, GPC, DSC, drug release measurements and monitoring dynamic changes in the systems' dry & wet mass and pH of the bulk fluid. Interestingly, the mesh structures were significantly different, although the device design (composition & theoretical geometry) were the same. This could be explained by the fact that the deposition of individual droplets during APF DDM led to curved and rather thick filaments, resulting in a much lower mesh porosity. In contrast, FDM printing generated straight and thinner filaments: The open spaces between them were much larger and allowed convective mass transport during drug release. Consequently, most of the drug was already released after 4 d, when substantial PLGA set on. In the case of APF DDM printed implants, most of the drug was still entrapped at that time point and substantial polymer swelling transformed the meshes into more or less continuous PLGA gels. Hence, the diffusion pathways became much longer and ibuprofen release was controlled over 2 weeks.


Subject(s)
Ibuprofen , Polymers , Humans , Polymers/chemistry , Drug Liberation , Printing, Three-Dimensional
5.
Int J Pharm X ; 4: 100131, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36189458

ABSTRACT

The aim of this study was to better understand the potential impact of partial vs. complete renewal of the bulk fluid during drug release measurements from poly (lactic-co-glycolic acid) (PLGA)-based implants. A "standard experimental set-up", in which the implants were directly exposed to well agitated phosphate buffer pH 7.4 was used, as well as set-ups, in which the implants were embedded within agarose hydrogels (mimicking living tissue). The gels were exposed to well agitated phosphate buffer pH 7.4. Ibuprofen-loaded implants were prepared by hot melt extrusion. The systems were thoroughly characterized before and during drug release by optical and scanning electron microscopy, gravimetric analysis, pH and solubility measurements as well as gel permeation chromatography. The bulk fluid was either completely or partially replaced by fresh medium at each sampling time point. In all cases, sink conditions were provided in the agitated bulk fluids throughout the experiments. Interestingly, the agarose set-ups did not show any noteworthy impact of the bulk fluid sampling volume on the observed drug release patterns, whereas complete fluid renewal in the "standard set-up" led to accelerated drug release. This could be explained by the considerable fragility of the implants once substantial polymer swelling set on, transforming them into PLGA gels: Complete fluid renewal caused partial disintegration and damage of the highly swollen systems, decreasing the lengths of the diffusion pathways for the drug. The mechanical stress is very much reduced at low sampling volumes, or if the implants are embedded within agarose gels. Thus, great care must be taken when defining the conditions for in vitro drug release measurements from PLGA-based implants: Once substantial system swelling sets on, the devices become highly fragile.

6.
Eur J Pharm Biopharm ; 177: 50-60, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35659920

ABSTRACT

The aim of this study was to better understand the importance of the diameter of poly(lactic-co-glycolic acid) (PLGA)-based implants on system performance, in particular the control of drug release. Different types of ibuprofen-loaded implants were prepared by hot melt extrusion using a Leistritz Nano 16 twin-screw extruder. Drug release was measured in well agitated phosphate buffer pH7.4 bulk fluid and in agarose gels in Eppendorf tubes or transwell plates. Dynamic changes in the implants' dry & wet mass, volume, polymer molecular weight as well as inner & outer morphology were monitored using gravimetric analysis, optical macroscopy, gel permeation chromatography and scanning electron microscopy. The physical states of the drug and polymer were determined by DSC. Also pH changes in the release medium were investigated. Irrespective of the type of experimental set-up, the resulting absolute and relative drug release rates decreased with increasing implant diameter (0.7-2.8 mm). Bi-phasic drug release was observed in all cases from the monolithic solutions (ibuprofen was dissolved in the polymer): A zero order release phase was followed by a final, rapid drug release phase (accounting for 80-90% of the total drug dose). The decrease in the relative drug release rate with increasing system diameter can be explained by the increase in the diffusion pathway lengths to be overcome. Interestingly, also the onset of the final rapid drug release phase was delayed with increasing implant diameter. This can probably be attributed to the higher mechanical stability of thicker devices, offering more resistance to substantial entire system swelling.


Subject(s)
Ibuprofen , Polymers , Drug Implants/chemistry , Drug Liberation , Ibuprofen/chemistry , Polylactic Acid-Polyglycolic Acid Copolymer/chemistry
8.
J Dairy Sci ; 104(11): 11537-11552, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34419267

ABSTRACT

Feeding low dietary cation-anion difference (DCAD) diets is one strategy to prevent milk fever in cows. The mechanism of action, as well as whether the calcium (Ca) supply of such diets combined with this feeding regimen should meet the requirements, is still unclear. Small ruminants are commonly used as models for cows. The goal of the present study was to demonstrate basic effects of DCAD against a background of different Ca supplies in a sheep model. Twenty-three castrated male East Friesian milk sheep, aged 11 to 12 mo, were randomly assigned to 4 different feeding groups. The ration of each group was either high (highDCAD) or low in DCAD (lowDCAD) combined with adequate (nCa) or restricted Ca supply (lowCa). At baseline, serum and urine were collected from all sheep and a peripheral quantitative computed tomography of the left metatarsus was performed. After a 14-d adaptation period to the different diets, the experiment started (d 0). Urine, feces, and serum were collected on d 0, 4, 7, 14, and 22, and peripheral quantitative computed tomography was performed on d 0 and 22. On d 22, the sheep were killed and sampled for functional studies. LowDCAD was significantly associated with lower urine pH, higher urinary Ca excretion, higher ionized Ca in blood, and higher serum Ca concentrations. Blood pH and bone parameters did not differ significantly between groups. It is unclear from which compartment the high amounts of Ca excreted with urine in the lowDCAD groups originated. Interestingly, lowDCAD resulted in higher renal mRNA abundance of parathyroid hormone receptor but unaffected mRNA abundance of Ca transporters. As neither renal abundance of these transporters nor Ca excretion were influenced by dietary Ca supply, our results support the hypothesis that increased urinary Ca observed with low DCAD diets represents a loss rather than an excretion of surplus Ca.


Subject(s)
Animal Feed , Calcium , Animal Feed/analysis , Animals , Anions , Calcium, Dietary , Cations , Cattle , Diet/veterinary , Female , Homeostasis , Hydrogen-Ion Concentration , Lactation , Male , Sheep
9.
Mol Immunol ; 68(2 Pt C): 575-84, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26320629

ABSTRACT

During the past two decades, a growing interest surrounding the interaction between microbe-associated molecular patterns (MAMPs) and pattern recognition receptors has occurred. This attention is now driven alongside bacterial-derived metabolites, which impact immune cell differentiation and function. Hence, this review introduces the term meta-MAMP as a means to classify the microbial derived-metabolites, which influence the immune response by affecting specific cellular processes. We discuss two prominent examples of meta-MAMPs: the first, rapamycin (isolated from Streptomyces), was discovered in the 1970s and since then has been thoroughly studied. The second, soraphen A (isolated from Myxobacteria), was discovered in the early 1990s but only recently identified as a promising immunomodulator. Both meta-MAMPs are similar in their remarkable capacity to modulate T cell fate by targeting key metabolic pathways triggered upon T cell activation. In this context, we highlight the progress made in the field of immunometabolism and the possibility of modulating metabolic pathways such as cellular fatty acid metabolism as a strategy for immunomodulation. We focus on the use of microbial metabolites as auspicious agents for T cell fate modulation.


Subject(s)
Lymphocyte Activation/immunology , Pathogen-Associated Molecular Pattern Molecules/immunology , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Animals , Humans
10.
J Microsc ; 250(2): 130-141, 2013 May.
Article in English | MEDLINE | ID: mdl-23573838

ABSTRACT

Microstructure analysis of polar ice cores is vital to understand the processes controlling the flow of polar ice on the microscale. This paper presents an automatic image processing framework for extraction and parametrization of grain boundary networks from images of the NEEM deep ice core. As cross-section images are acquired using controlled surface sublimation, grain boundaries and air inclusions appear dark, whereas the inside of grains appears grey. The initial segmentation step of the software is to separate possible boundaries of grains and air inclusions from background. A Machine learning approach is utilized to gain automatic, reliable classification, which is required for processing large data sets along deep ice cores. The second step is to compose the perimeter of section profiles of grains by planar sections of the grain surface between triple points. Ultimately, grain areas, grain boundaries and triple junctions of the later are diversely parametrized. High resolution is achieved, so that small grain sizes and local curvatures of grain boundaries can systematically be investigated.

11.
Clin Nephrol ; 76(1): 49-56, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21722605

ABSTRACT

BACKGROUND: Henoch-Schönlein purpura (HSP) is a fairly common disease in children and adolescents. There are only limited data available for adults. METHODS: A retrospective analysis was conducted to study renal manifestations in patients with HSP treated in our institution between 1982 and 2007. We divided our adult cohort according to age - under or over 60 years - to examine differences in elderly patients. RESULTS: HSP was identified in 2.2% of patients referred to us for kidney biopsy. Purpuric lesions and renal involvement were found in all patients. An important triggering factor for the development of HSP in our series was chronic alcohol intake. Forty percent of our patients fulfilled the WHO criteria for alcoholics. Renal involvement was particularly prominent in patients over 60 years of age. At disease onset, estimated glomerular filtration rate (eGFR) was 63% lower in the elderly. Within a median follow-up of 8 years, renal function was significantly better in younger adults than in the elderly. 32% of the elderly have shown Modification of Diet in Renal Disease (MDRD) < 20 ml/min/1.73 m2 in contrast to only 7% in patients < 60 years. Furthermore, significantly more elderly patients reached end-stage renal failure. CONCLUSION: The data indicate that renal manifestation of HSP in the elderly is severe and its outcome relatively poor, and worsens when compared to patients < 60 years.


Subject(s)
IgA Vasculitis/pathology , Kidney Diseases/pathology , Adolescent , Adult , Aged , Aged, 80 and over , Aging , Biopsy , Female , Glomerular Filtration Rate , Humans , IgA Vasculitis/physiopathology , IgA Vasculitis/therapy , Kidney/pathology , Kidney Diseases/physiopathology , Kidney Diseases/therapy , Male , Middle Aged , Prognosis , Risk Factors , Skin/pathology , Young Adult
12.
Chem Senses ; 25(4): 413-21, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10944505

ABSTRACT

G protein betagamma (Gbetagamma) complexes are considered to play an important role in second messenger signaling of phospholipase C (PLC). Monitoring the inositol 1,4,5-trisphosphate (IP(3)) response in circumvallate tissue homogenates upon stimulation with denatonium benzoate, it was demonstrated that a glutathione S-transferase-GRK3ct fusion protein-a Gbetagamma scavenger-attenuates the bitter tastant-induced second messenger reaction. Towards an identification of the Gbetagamma complex involved in rat bitter taste transduction, it was found that the G protein beta(3) subtype is specifically expressed in taste receptor cells of circumvallate papillae. Gbeta(3)-specific antibodies blocked the denatonium benzoate-induced IP(3) formation in a dose-dependent manner; the inhibitory effect was reversed by preincubation with the antigenic peptide. A less pronounced inhibition was observed using Gbeta(1)-specific antibodies. Analyzing individual taste cells by single cell reverse transcriptase-polymerase chain reaction approaches, overlapping expression patterns for PLCbeta(2), Galpha(gust), Gbeta(3) and Ggamma(3) could be demonstrated. Furthermore, the co-expression of all profiled signal transduction components in individual taste receptor cells could be detected. These data support the concept that the denatonium benzoate-induced IP(3) response is mediated by an activation of PLCbeta(2) via a Gbetagamma complex, possibly composed of Gbeta(3) as the predominant beta subunit and Ggamma(3), and imply that multiple second messenger pathways may exist in individual taste receptor cells.


Subject(s)
GTP-Binding Proteins/physiology , Signal Transduction/physiology , Taste Buds/physiology , Animals , Base Sequence , DNA Primers , GTP-Binding Proteins/metabolism , Immunohistochemistry , Inositol 1,4,5-Trisphosphate/metabolism , Rats , Rats, Sprague-Dawley , Reverse Transcriptase Polymerase Chain Reaction , Taste Buds/cytology , Taste Buds/metabolism
13.
Biotechnol Bioeng ; 69(5): 559-65, 2000 Sep 05.
Article in English | MEDLINE | ID: mdl-10898865

ABSTRACT

This investigation examines phase equilibrium phenomena that can be used to create two water-like solvents for liquid-liquid extraction in downstream processing in biotechnology: a completely miscible, binary liquid mixture of water and a hydrophilic organic solvent (e. g., an alcohol) reveals a liquid phase split, when it is pressurized with a "near-critical" gas (i.e., a substance which at ambient conditions is a gas, near its critical temperature). This phase split results in two hydrophilic liquid phases. Making use of this phenomenon in process development first requires research on the phase split phenomenon and, second, research on the feasibility of biomolecule extraction and separation. In this study, basic fluid phase equilibrium phenomena are briefly described. Then, experimental results are reported for the partitioning of small amounts of cardiac glycosides (digitoxin and digoxin) on coexisting liquid phases in the high-pressure, three-phase, vapor-liquid-liquid equilibrium of the ternary system of "near critical" CO(2) + water + 1-propanol, at 313 K and 333 K. Finally, a process for extraction and separation of the aforementioned glycosides by means of the high-pressure phase equilibrium phenomenon is discussed.


Subject(s)
Biotechnology/instrumentation , Biotechnology/methods , Digitoxin/isolation & purification , Digoxin/isolation & purification , 1-Propanol/chemistry , Carbon Dioxide/chemistry , Chromatography, High Pressure Liquid/instrumentation , Chromatography, High Pressure Liquid/methods , Digitoxin/chemistry , Digoxin/chemistry , Water/chemistry
14.
Crit Care Med ; 27(8): 1478-85, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10470753

ABSTRACT

OBJECTIVE: To evaluate the safety and efficacy of an intravenous liposomal dispersion of prostaglandin E1 as TLC C-53 in the treatment of patients with acute respiratory distress syndrome (ARDS). DESIGN: Randomized, prospective, multicenter, double-blind, placebo-controlled, phase III clinical trial. SETTING: Forty-seven community and university-affiliated hospitals in the United States. PATIENTS: A total of 350 patients with ARDS were enrolled in this clinical trial. INTERVENTION: Patients were prospectively randomized in a 1:1 ratio to receive either liposomal prostaglandin E1 or placebo. The study drug was infused intravenously for 60 mins every 6 hrs for 7 days starting with a dosage of 0.15 microg/kg/hr. The dose was increased every 12 hrs until the maximal dose (3.6 microg/kg/hr) was attained or intolerance to further increases developed. Patients received standard aggressive medical/surgical care during the infusion period. OUTCOME MEASURES: The primary outcome measure was the time it took to wean the patient from the ventilator. Secondary end points included time to improvement of the PaO2/FIO2 ratio (defined as first PaO2/FIO2 > 300 mm Hg), day 28 mortality, ventilator dependence at day 8, changes in PaO2/FIO2, incidence of and time to development/resolution of organ failure other than ARDS. RESULTS: A total of 348 patients could be evaluated for efficacy. The distribution of variables at baseline describing gender, lung injury scores, Acute Physiology and Chronic Health Evaluation II scores, PaO2/FIO2, pulmonary compliance, and time from onset of ARDS or from institution of mechanical ventilation to the first dose of study drug was similar among patients in the liposomal prostaglandin E1 (n = 177) and the placebo (n = 171) treatment arms. There was no significant difference in the number of days to the discontinuation of ventilation in the liposomal prostaglandin E1 group compared with the placebo group (median number of days to off mechanical ventilation, 16.9 in patients receiving liposomal prostaglandin E1 and 19.6 in those administered placebo; p = .94). Similarly, mortality at day 28 was not significantly different in the two groups (day 28 mortality, 57 of 176 (32%) in the liposomal prostaglandin E1 group and 50 of 170 (29%) in patients receiving placebo; p = .55). In contrast, treatment with liposomal prostaglandin E1 was associated with a significantly shorter time to reach a PaO2/FIO2 ratio of >300 mm Hg (median number of days to reaching a PaO2/FIO2 ratio >300 mm Hg: 9.8 days in the liposomal prostaglandin E1 group and 13.7 days in patients receiving the placebo; p = .02). Among the subgroups examined, time to off mechanical ventilation was significantly reduced in patients who received at least 85% of a full dose (i.e., > 45.9 microg/kg) of liposomal prostaglandin E1 (median number of days to discontinuation of ventilation, 10.3 in the liposomal prostaglandin E1 group and 16.3 days in patients receiving placebo; p = .05). The overall incidence of serious adverse events was not significantly different in the liposomal prostaglandin E1 (40%) or placebo-treated (37%) groups. Drug-related adverse events of all kinds were reported in 69% of the patients receiving liposomal prostaglandin E1 compared with 33% of the placebo group, with hypotension and hypoxia (occurring in 52% and 24% of the liposomal prostaglandin E1-treated patients, respectively, and 17% and 5% of the placebo-treated patients, respectively) being noted most frequently. CONCLUSIONS: In the intent-to-treat population of patients with ARDS, treatment with liposomal prostaglandin E1 accelerated improvement in indexes of oxygenation but did not decrease the duration of mechanical ventilation and did not improve day 28 survival.


Subject(s)
Alprostadil/administration & dosage , Drug Carriers , Liposomes , Respiratory Distress Syndrome/drug therapy , Vasodilator Agents/administration & dosage , Adult , Aged , Alprostadil/adverse effects , Double-Blind Method , Female , Hospital Mortality , Humans , Hypotension/chemically induced , Hypoxia/chemically induced , Infusions, Intravenous , Male , Middle Aged , Multiple Organ Failure/etiology , Prospective Studies , Respiratory Distress Syndrome/complications , Respiratory Distress Syndrome/mortality , Respiratory Distress Syndrome/therapy , Survival Analysis , Time Factors , Vasodilator Agents/adverse effects , Ventilator Weaning
15.
Gene ; 226(2): 165-74, 1999 Jan 21.
Article in English | MEDLINE | ID: mdl-10084886

ABSTRACT

In vertebrates, recognition of odorous compounds is based on a large repertoire of receptor subtypes encoded by a multigene family. Towards an understanding of the phylogenetic origin of the vertebrate olfactory receptor family, attempts have been made to identify related receptor genes in the river lampreys (Lampetra fluviatilis), which are descendants of the earliest craniates and living representatives of the most ancient vertebrates. Employing molecular cloning approaches led to the discovery of four genes encoding heptahelical receptors, which share only a rather low overall sequence identity but several of the characteristic structural hallmarks with vertebrate olfactory receptors. Furthermore, in situ hybridization studies demonstrated that the identified genes are expressed in chemosensory cells of the singular lamprey olfactory organ. Molecular phylogenetic analysis confirmed a close relationship of the lamprey receptors to vertebrate olfactory receptors and in addition demonstrated that olfactory genes of the agnathostomes diverged from the gnathostome receptor genes before those split into class I and class II receptors. The data indicate that the lamprey receptors represent the most ancient family of the hitherto identified vertebrate olfactory receptors.


Subject(s)
Lampreys/genetics , Receptors, Odorant/genetics , Amino Acid Sequence , Animals , Base Sequence , DNA Primers , DNA, Complementary , Lampreys/classification , Molecular Sequence Data , Phylogeny , Sequence Homology, Amino Acid
16.
J Exp Biol ; 202(Pt 4): 365-76, 1999 Feb.
Article in English | MEDLINE | ID: mdl-9914145

ABSTRACT

A coordinated expression of tissue- and cell-specific genes during development is required to establish the complex functional organization of the vertebrate olfactory system. Owing to the unique features of its olfactory system and the well-characterized phases of its development, Xenopus laevis was chosen as a model organism to study the onset and the temporal and spatial patterns of expression of olfactory-specific genes. Using RT-PCR and in situ hybridization, it was found that expression of Xenopus olfactory marker protein and of class I receptors, which are thought to be responsible for the perception of water-soluble odorants, was detectable as early as stage 32, less than 2 days after fertilization. In contrast, expression of class II receptors, which are thought to recognize airborne odours, was not detected before stage 49, approximately 12 days after fertilization. The results indicate that the expression of olfactory receptors and marker protein is governed by temporally regulated cues during development.


Subject(s)
Olfactory Receptor Neurons/growth & development , Xenopus laevis/growth & development , Animals , Base Sequence , DNA Primers/genetics , Gene Expression Regulation, Developmental , In Situ Hybridization , Olfactory Receptor Neurons/embryology , Olfactory Receptor Neurons/physiology , RNA, Messenger/genetics , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Xenopus laevis/embryology , Xenopus laevis/genetics
17.
J Comp Physiol A ; 183(5): 635-50, 1998 Nov.
Article in English | MEDLINE | ID: mdl-9839455

ABSTRACT

In species representing different levels of vertebrate evolution, olfactory receptor genes have been identified by molecular cloning techniques. Comparing the deduced amino-acid sequences revealed that the olfactory receptor gene family of Rana esculenta resembles that of Xenopus laevis, indicating that amphibians in general may comprise two classes of olfactory receptors. Whereas teleost fish, including the goldfish Carassius auratus, possess only class I receptors, the 'living fossil' Latimeria chalumnae is endowed with both receptor classes; interestingly, most of the class II genes turned out to be pseudogenes. Exploring receptor genes in aquatic mammals led to the discovery of a large array of only class II receptor genes in the dolphin Stenella Coeruleoalba; however, all of these genes were found to be non-functional pseudogenes. These results support the notion that class I receptors may be specialized for detecting water-soluble odorants and class II receptors for recognizing volatile odorants. Comparing the structural features of both receptor classes from various species revealed that they differ mainly in their extracellular loop 3, which may contribute to ligand specificity. Comparing the number and diversity of olfactory receptor genes in different species provides insight into the origin and the evolution of this unique gene family.


Subject(s)
Olfactory Receptor Neurons/physiology , Smell/physiology , Animals , Blotting, Southern , Brain Chemistry/physiology , Dolphins , Evolution, Molecular , Gene Expression/physiology , Goldfish , Molecular Sequence Data , Multigene Family/physiology , Nerve Tissue Proteins/genetics , Olfactory Receptor Neurons/chemistry , Phylogeny , Pseudogenes/physiology , Rana esculenta , Sequence Homology, Amino Acid , Species Specificity , Vertebrates , Xenopus laevis
18.
Eur J Cell Biol ; 77(3): 253-61, 1998 Nov.
Article in English | MEDLINE | ID: mdl-9860142

ABSTRACT

From rat circumvallate papillae a novel phospholipase C (PLC) subtype has been cloned and identified as most closely related to human PLC beta2. The corresponding mRNA was only detected in sensory lingual tissue but not in non-taste lingual tissue or any other tissues examined by Northern blot analysis. In situ hybridization revealed that a subset of taste receptor cells of circumvallate papillae was specifically labeled. A functional involvement of this PLC beta subtype in taste signal transduction emerged from biochemical analysis monitoring the second messenger response in circumvallate preparations induced by denatonium benzoate. This bitter agent elicited a rapid and transient increase of the inositol 1,4,5-trisphosphate level; this response was blocked by U73122, a potent inhibitor of PLC, and by PLC beta2-specific antibodies. These data indicate that a phospholipase C beta2 isoform mediates a denatonium benzoate-induced second messenger response of taste sensory cells in the circumvallate papillae.


Subject(s)
Isoenzymes/genetics , Taste Buds/chemistry , Tongue/chemistry , Type C Phospholipases/genetics , Amino Acid Sequence , Animals , Antibodies/pharmacology , Blotting, Northern , Blotting, Western , Humans , Immunohistochemistry , In Situ Hybridization , Inositol 1,4,5-Trisphosphate/metabolism , Isoenzymes/immunology , Molecular Sequence Data , Phospholipase C beta , Quaternary Ammonium Compounds/pharmacology , RNA, Messenger/analysis , Rats , Reverse Transcriptase Polymerase Chain Reaction , Sequence Alignment , Sequence Homology, Amino Acid , Taste Buds/drug effects , Taste Buds/metabolism , Type C Phospholipases/immunology
20.
Ann Allergy Asthma Immunol ; 76(2): 181-8, 1996 Feb.
Article in English | MEDLINE | ID: mdl-8595539

ABSTRACT

BACKGROUND: Azelastine is a chemically novel investigational antiallergy drug with the ability to antagonize the effects of chemical mediators of the early- phase and late phase allergic responses suggesting its usefulness in the treatment of upper and lower airway diseases. OBJECTIVE: The objective of this 4-week, double- bind, multicenter trial was to evaluate the efficacy of azelastine nasal spray in subjects with seasonal allergic rhinitis. METHODS: Two hundred sixty-four subjects 12 years of age and older were randomized to receive either azelastine, 2 sprays/nostril qd; azelastine, 2 sprays/nostril bid; oral chlorpheniramine maleate, 12 mg bid; or placebo. The primary efficacy parameters were the changes in major and total symptom severity scores. RESULTS: Overall, across all 4 weeks of treatment, the mean percent improvements in the total and major symptom complex severity scores in both azelastine treatment groups were greater than those for the placebo group. For the azelastine 2 sprays bid group, the overall results were significant at P = .05 for the major symptom complex score and at .05 < P = .10 for the total symptom complex score versus placebo. For both azelastine treatment groups, improvements in all of the individual rhinitis symptoms were superior to those for the placebo group and, in general were clinically and statistically significant. Azelastine nasal spray was well tolerated; adverse experiences were generally application site reactions, mild to moderate, and not limiting to continued treatment. CONCLUSIONS: Azelastine nasal spray demonstrated broad clinical antirhinitis activity that for the 2 sprays/nostril bid dosage regimen was consistently clinically and statistically significant.


Subject(s)
Histamine H1 Antagonists/therapeutic use , Phthalazines/therapeutic use , Rhinitis, Allergic, Seasonal/drug therapy , Administration, Intranasal , Adolescent , Adult , Child , Double-Blind Method , Female , Histamine H1 Antagonists/administration & dosage , Histamine H1 Antagonists/adverse effects , Humans , Male , Middle Aged , Phthalazines/administration & dosage , Phthalazines/adverse effects
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