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1.
J Equine Vet Sci ; 136: 105063, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38608970

RESUMO

A 17-year-old mare presenting with acute fever, weakness and bladder dysfunction was diagnosed with equine herpesvirus myeloencephalopathy (EHM). The mare become transiently recumbent, underwent parenteral fluid therapy, plasma infusion, steroidal/nonsteroidal anti-inflammatory drugs (SAID/NSAIDs) and bladder catheterization. After 10 days the mare was hospitalized. Neurological evaluation revealed ataxia and proprioceptive deficits mainly in the hind limbs. The mare was able to stand but unable to rise from recumbency or walk. Secondary complications included Escherichia coli cystitis, corneal ulcers and pressure sores. A full-body support sling was used for 21 days. Medical treatment included systemic antimicrobials, NSAIDs, gradual discontinuation of SAIDs, parenteral fluid therapy and bladder lavage. The mare tested positive for Varicellovirus equidalpha 1 (EHV-1) DNA in nasal swab and blood samples on day 13 and in urine samples on days 13 and 25 after the onset of fever. Neurological signs improved over a period of 34 days and the mare was discharged with mild hind limb weakness/ataxia. Secondary complications resolved within 2 weeks. At the eight-month follow-up, marked improvement in locomotory function had been achieved.


Assuntos
Infecções por Herpesviridae , Doenças dos Cavalos , Cavalos , Animais , Feminino , Doenças dos Cavalos/virologia , Doenças dos Cavalos/tratamento farmacológico , Infecções por Herpesviridae/tratamento farmacológico , Infecções por Herpesviridae/veterinária , Infecções por Herpesviridae/complicações , Herpesvirus Equídeo 1/efeitos dos fármacos
2.
Artigo em Inglês | MEDLINE | ID: mdl-37022805

RESUMO

Recent studies on human upper limb motion highlighted the benefit of dimensionality reduction techniques to extrapolate informative joint patterns. These techniques can simplify the description of upper limb kinematics in physiological conditions, serving as a baseline for the objective assessment of movement alterations, or to be implemented in a robotic joint. However, the successful description of kinematic data requires a proper alignment of the acquisitions to correctly estimate kinematic patterns and their motion variability. Here, we propose a structured methodology to process and analyze upper limb kinematic data, considering time warping and task segmentation to register task execution on a common normalized completion time axis. Functional principal component analysis (fPCA) was used to extract patterns of motion of the wrist joint from the data collected by healthy participants performing activities of daily living. Our results suggest that wrist trajectories can be described as a linear combination of few functional principal components (fPCs). In fact, three fPCs explained more than 85% of the variance of any task. Wrist trajectories in the reaching phase of movement were highly correlated among participants and significantly more than trajectories in the manipulation phase ( [Formula: see text]). These findings may be useful in simplifying the control and design of robotic wrists, and could aid the development of therapies for the early detection of pathological conditions.


Assuntos
Atividades Cotidianas , Punho , Humanos , Punho/fisiologia , Extremidade Superior/fisiologia , Movimento (Física) , Articulação do Punho , Movimento/fisiologia , Fenômenos Biomecânicos , Amplitude de Movimento Articular/fisiologia
3.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 6220-6223, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34892536

RESUMO

Archery technique requires a coordinated activation of shoulder girdle and upper extremity muscles to perform a successful shot. The analysis of muscle synergies can provide information about the motor strategy that underlies the shooting performance, also supporting the investigation of motor impairments in athletes with disability. For this purpose, electromyographic (EMG) data from five muscles were collected from a non-disabled and a W1 category Paralympic athlete, and muscle synergies were extracted from EMG envelopes using non-negative matrix factorization. Muscle synergies analysis revealed features of the motor strategy specific to the athletes' shooting technique, such as the contribution of the biceps muscle instead of the posterior deltoid during the arrow drawing and target aiming in the Paralympic athlete compared to the non-disabled athlete. It is concluded that the evaluation of the muscle synergies may be a valuable tool for exploring the motor strategies adopted by athletes with disability, providing useful information to improve athletic performance and possibly prevent the risk of injury.


Assuntos
Atletas , Extremidade Superior , Fenômenos Biomecânicos , Humanos , Músculo Esquelético , Ombro
4.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 937-940, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34891444

RESUMO

Human motion analysis is gaining increased importance in several fields, from movement assessment in rehabilitation to recreational applications such as virtual coaching. Among all the technologies involved in motion capture, Magneto-Inertial Measurements Units (MIMUs) is one of the most promising due to their small dimensions and low costs. Nevertheless, their usage is strongly limited by different error sources, among which magnetic disturbances, which are particularly problematic in indoor environments. Inertial Measurement Units (IMUs) could, thus, be considered as alternative solution. Indeed, relying exclusively on accelerometers and gyroscopes, they are insensitive to magnetic disturbances. Even if the literature has started to propose few algorithms that do not take into account magnetometer input, their application is limited to robotics and aviation. The aim of the present work is to introduce a magnetic-free quaternion based Extended Kalman filter for upper limb kinematic assessment in human motion (i.e., yoga). The algorithm was tested on five expert yoga trainers during the execution of the sun salutation sequence. Joint angle estimations were compared with the ones obtained from an optoelectronic reference system by evaluating the Mean Absolute Errors (MAEs) and Pearson's correlation coefficients. The achieved worst-case was 6.17°, while the best one was 2.65° for MAEs mean values. The accuracy of the algorithm was further confirmed by the high values of the Pearson's correlation coefficients (lowest mean value of 0.86).Clinical Relevance- The proposed work validated a magnetic free algorithm for kinematic reconstruction with inertial units. It could be used as a wearable solution to track human movements in indoor environments being insensitive to magnetic disturbances, and thus could be potentially used also for rehabilitation purposes.


Assuntos
Yoga , Fenômenos Biomecânicos , Humanos , Movimento (Física) , Movimento , Extremidade Superior
5.
Annu Int Conf IEEE Eng Med Biol Soc ; 2019: 2443-2446, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31946392

RESUMO

Unbalancing events during gait can end up in falls and, thus, injury. Detecting events that could bring to fall and consequently activating fall prevention systems before the impact may help to mitigate related injuries. However, there is uncertainty about signals and methods that could offer the best performance. In this paper we investigated a novel trip detection method based on time-frequency features to evaluate the performances of these features as trip detectors. Hip angles of eight healthy young subjects were recorded while performing unexpected tripping trials delivered during steady locomotion. Then the Short-Time Fourier Transform (STFT) of the hip angle was estimated. Median frequency, power, centroidal frequency as well as frequency dispersion were computed for each time sliced power spectrum. These features were used as input for a trip detection algorithm. We assessed detection time (Tdetect), specificity (Spec) and sensitivity (Sens) for each feature. Performances obtained with median frequencies over time(Tdetect 0.91 ± 0.47 s; Sens 0.96) were better than those obtained using the hip angle signal in time domain (Tdetect 1.19 ± 0.27 s; Sens 0.83). Other features did not show significant results. Thus, median frequency over time expected to achieve effective real-time event detection systems, with the aim of a future on-board application concerning detection and prevention measures.


Assuntos
Algoritmos , Marcha , Caminhada , Fenômenos Biomecânicos , Humanos
6.
J Fish Biol ; 83(4): 921-38, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24090555

RESUMO

A medium-term (10 year) stochastic forecast model is developed and presented for mixed fisheries that can provide estimations of age-specific parameters for a maximum of 10 stocks and 10 fisheries. Designed to support fishery managers dealing with complex, multi-annual management plans, the model can be used to quantitatively test the consequences of various stock-specific and fishery-specific decisions, using non-equilibrium stock dynamics. Such decisions include fishing restrictions and other strategies aimed at achieving sustainable mixed fisheries consistent with the concept of maximum sustainable yield (MSY). In order to test the model, recently gathered data on seven stocks and four fisheries operating in the Ligurian and North Tyrrhenian Seas are used to generate quantitative, 10 year predictions of biomass and catch trends under four different management scenarios. The results show that using the fishing mortality at MSY as the biological reference point for the management of all stocks would be a strong incentive to reduce the technical interactions among concurrent fishing strategies. This would optimize the stock-specific exploitation and be consistent with sustainability criteria.


Assuntos
Conservação dos Recursos Naturais/métodos , Pesqueiros/métodos , Modelos Teóricos , Animais , Biomassa , Mar Mediterrâneo , Dinâmica Populacional
7.
J Environ Monit ; 7(12): 1265-74, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16307082

RESUMO

During the 2002-2003 austral summer field season, aerosol samples were collected at a coastal (Terra Nova Bay--Northern Victoria Land) and an inland site (Dome C--East Antarctic Plateau). The sampling was carried out by stacked filter units made up of two filters at different porosity (5.0 and 0.4 microm at Terra Nova Bay and 3.0 and 0.4 microm at Dome C), able to roughly separate a coarse from a fine fraction. At Dome C, a further investigation on aerosol size distribution was performed by an inertial impactor able to collect aerosol particles on 8 size classes (from 10 to 0.4 microm). Atomic Force Microscopy was applied to the filter collecting the finer fraction in both sites in order to assess the real cut-off value of the filter sandwich apparatus and to reconstruct the volume size distribution. At the employed flow conditions, the real cut-off value was revealed to be about one third with respect to the filter nominal porosity in both stations. The size distribution plots showed a bimodal distribution with a mode centered around 0.22 microm in both the sites and a second broader mode which is centered between 0.3 microm and 1.2 microm diameter at Terra Nova Bay and shifted toward higher values (centred around 1.0 microm diameter) at Dome C. Each filter was analysed for the main and trace ionic components allowing evaluation of the contributions of primary and secondary aerosol sources at the two sites as a function of the particle size class. The coastal site is mainly affected by primary and secondary marine inputs: the sea spray contribution (Na+, Mg2+, Cl- and ssSO4(2-)) is dominant (77% w/w) in the coarse fraction whereas the biogenic source (methanesulfonate and nssSO4(2-)) prevails (67.5% w/w) in the fine fraction. In this fraction a significant contribution (15.5% w/w) is provided by ammonium likely to be related to surrounding penguin colonies. Dome C atmosphere is characterised by fine particles arising from secondary sources and long-range transport processes. The main component in the fine and coarse fractions at Dome C is sulfate whose nssSO4(2-) represents the 99.5% and the 92.3%(w/w) in fine and coarse fraction, respectively. The observed agreement between nssSO4(2-) and methanesulfonate temporal profiles in the fine fraction demonstrates that biogenic emissions dominate the inland background aerosol. Results from the sampling by the 8-stage impactor at Dome C are presented here: chloride and nitrate are mainly deposited on the 10-2.1 microm stages while the highest sulfate concentration was found in the submicrometric fraction which turned out to be the most acidic. Such a distribution is able to prevent nitrate and chloride re-emission as gaseous HCl and HNO3 in the 10-2.1 microm stages, arising from the exchange reaction between chloride and nitrate salts and sulfuric acid. Moreover, the concentration peak observed for nitrate in coarser fractions is probably related also to the formation of hygroscopic NH4NO3 particles and nitrate adsorption on sea salt particles.


Assuntos
Aerossóis/análise , Regiões Antárticas , Cloretos/análise , Monitoramento Ambiental , Magnésio/análise , Microscopia de Força Atômica , Tamanho da Partícula , Estações do Ano , Água do Mar , Sulfatos/análise
8.
Biochim Biophys Acta ; 1484(2-3): 87-92, 2000 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-10760459

RESUMO

The aim of this study was to investigate to what extent the generation of leukotrienes (LTs) and lipoxins (LXs) was affected by the expression of definite levels of macrophage activation. We used a system of murine peritoneal macrophages at different states of activation consisting in resident macrophages and FCS-, thioglycollate- or Corynebacterium parvum-elicited macrophages. The profile of lipoxygenase metabolites in resident macrophages was characterized by the presence of high levels of 12-HETE, followed by 15-HETE, 5-HETE, LTB(4) and 6-trans-LTB(4), 6-trans-12-epi-LTB(4). A comparable pattern was also found in FCS-elicited macrophages which appeared not to be responsive to the challenge with interferon gamma plus LPS, as measured by the generation of NO and tumor necrosis factor alpha. Resident as well as FCS-elicited macrophages also generated appreciable quantities of LXs (A(4) and B(4)). Thioglycollate-elicited macrophages, which expressed a state of 'responsive' macrophages, showed a block of the LT and LX synthesis. This block was also present in C. parvum-elicited macrophages which expressed a fully 'activated' phenotype, reflected by their capacity of releasing NO and tumor necrosis factor alpha even though they were not challenged. These results provide the first evidence that the level of 'responsive' as well as 'activated' macrophages was associated with of a simultaneous block of LTB(4) and LXs.


Assuntos
Ácidos Araquidônicos/metabolismo , Leucotrienos/metabolismo , Macrófagos Peritoneais/metabolismo , Animais , Sangue , Cromatografia Líquida de Alta Pressão , Interferon gama , Lipopolissacarídeos , Ativação de Macrófagos , Camundongos , Óxido Nítrico/análise , Propionibacterium acnes , Tioglicolatos , Fator de Necrose Tumoral alfa/análise
9.
Clin Exp Metastasis ; 17(4): 271-6, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10545012

RESUMO

Interest in lipid characteristics of metastatic cells was aroused by the consideration that the various lipid components of cell membranes influence a broad spectrum of cell surface biological functions which are involved in different steps of the metastatic cascade. Correlation between invasive properties and characteristics of cell surface components has been appropriately studied in a limited number of metastatic cell systems isolated by in vivo and in vitro procedures. The major findings of this study have been reported in this review. Among membrane lipid components, glycolipids and phospholipids appeared particularly affected in tumor cells which acquired a metastatic phenotype. In fact, the reduction of complex gangliosides typical of transformed cell lines was even more evident in a highly metastatic variant selected from RSV-transformed murine fibroblasts. The reduction of complex gangliosides, mainly GD1a, particularly affected the adhesion sites of this variant. In a fibrosarcoma line, T3 cells, the metastatic properties appeared to be correlated with the content and cell surface expression of Gb3ose, a glycolipid characteristic of this line. Moreover, a particularly high level of ether-linked lipids was found in high metastatic variants isolated from murine melanoma and fibrosarcoma lines, as well as in human mammary carcinomas. The findings considered in this review are discussed for their possible relevance to the invasive properties of metastatic cells.


Assuntos
Glicolipídeos/metabolismo , Metástase Neoplásica , Neoplasias/metabolismo , Fosfolipídeos/metabolismo , Animais , Humanos , Neoplasias/patologia
10.
Clin Exp Metastasis ; 17(10): 889-95, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-11089888

RESUMO

A previous study by our laboratory showed that the peritoneal murine Corynebacterium parnum-elicited macrophages released into their growth medium an activity which enhanced the ability of B16-F10 melanoma cells to form experimental metastases in the lung of syngeneic mice. In the present study, we used a clone of B16-F10 line (F10-M3 cells) to investigate whether the increase in lung-colonizing potential due to the pro-clonogenic activity released by C. parvum-elicited macrophages was associated with biological properties characteristic of a metastatic phenotype. We have found that the pulmonary retention, growth rate in lung parenchyma, invasiveness through Matrigel, adhesiveness to IL-1-activated endothelium and MHC class I expression were increased in F10-M3 cells stimulated by the macrophage pro-clonogenic activity. By using an in vitro experimental protocol, the enhancement of lung-colonizing potential in the stimulated melanoma cells turned out to be a transient phenomenon as was the increase of invasiveness through Matrigel and the higher expression of MHC class I antigens. In conclusion, the melanoma cells stimulated by the pro-clonogenic activity released by C. parvum-elicited macrophages showed changes in biological parameters which are relevant to metastatic diffusion. These changes appeared as a temporary phenomenon which sustains the view that the metastatic phenotype represents a transient biological character influenced by host factors.


Assuntos
Neoplasias Pulmonares/patologia , Macrófagos/imunologia , Melanoma/imunologia , Melanoma/patologia , Animais , Testes de Carcinogenicidade , Adesão Celular , Divisão Celular , Meios de Cultivo Condicionados , Endotélio Vascular/citologia , Antígenos H-2/biossíntese , Humanos , Macrófagos/microbiologia , Melanoma/secundário , Camundongos , Invasividade Neoplásica , Propionibacterium acnes , Células Tumorais Cultivadas
11.
Clin Exp Metastasis ; 16(5): 407-14, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10091936

RESUMO

In a previous study we found that the capacity for spontaneous metastases of tumors developed after subcutaneous transplantation of RSV-transformed Balb/c 3T3 cells was reduced in essential fatty acids (EFA)-deficient host animals. In the present study, we have extended our investigation by considering the requirement of EFA for the formation of lung colonies obtained by i.v. injection of two metastatic murine cell lines of different origin: (1) T3 cells, a highly metastatic cell line isolated from a fibrosarcoma, and (2) the F10 variant of B16 melanoma (B16-F10 cells). We found that EFA deficiency reduces the lung colonization of both T3 cells and B16-F10 cells without affecting the retention of tumor cells in the lung. NK cells did not seem to be involved in the diminution of lung colonization in EFA-deficient animals. Furthermore, by examining histologically the lung parenchyma at successive intervals after tumor cell injection, we found that, in comparison with control mice, EFA-deficient animals had fewer lung colonies and a prevalence of smaller microcolonies during the entire period of observation. This led us to conclude that the diminution in development of tumor colonies in the lungs of EFA-deficient host animals was related to a reduced growth rate of tumor cells at this site.


Assuntos
Ácidos Graxos Essenciais/metabolismo , Neoplasias Pulmonares/secundário , Melanoma Experimental/secundário , Metástase Neoplásica , Animais , Feminino , Células Matadoras Naturais/imunologia , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas/secundário , Neoplasias Pulmonares/imunologia , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Transplante de Neoplasias , Células Tumorais Cultivadas
12.
Clin Exp Metastasis ; 15(2): 94-101, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9062385

RESUMO

In order to explore the influence of activated macrophages on tumor cells, we cultured a series of weakly metastatic clones isolated from the murine T3 fibrosarcoma line (T3 clones) and the B16-F10 melanoma cells on feeder layers of C. parvum- or thioglycollate-elicited macrophages, or 'resident' (unstimulated) macrophages. Co-cultivation with C. parvum-elicited macrophages, but not with resident macrophages, induced an increase of the lung-colonizing potential of T3 clones and B16-F10 cells. An enhancement of lung-colonizing potential was also found in tumor cells grown in media conditioned by C. parvum-elicited macrophages. Thioglycollate-elicited macrophages also generated a pro-clonogenic activity which was however effective only on T3 clones but not on B16-F10 cells. The increase in the lung-colonizing potential of tumor cells stimulated by activated macrophages was retained to some degree after subcultivation in tissue culture medium or transplantation into syngeneic animals. In conclusion, our data support the notion that macrophages at different states of activation may enhance lung colonization of tumor cells by inducing a partially stable change of phenotype.


Assuntos
Fibrossarcoma/secundário , Neoplasias Pulmonares/secundário , Ativação de Macrófagos , Macrófagos Peritoneais/fisiologia , Melanoma Experimental/secundário , Animais , Técnicas de Cultura de Células , Divisão Celular , Meios de Cultivo Condicionados , Feminino , Fibrossarcoma/patologia , Neoplasias Pulmonares/patologia , Macrófagos Peritoneais/efeitos dos fármacos , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Propionibacterium acnes , Tioglicolatos
14.
J Cell Biol ; 122(5): 1131-43, 1993 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8354696

RESUMO

Electrical signals elicited by integrin interaction with ECM components and their role in neurite outgrowth were studied in two clones (N1 and N7) isolated from 41A3 murine neuroblastoma cell line. Although the two clones similarly adhered to fibronectin (FN) and vitronectin (VN), this adhesion induced neurite outgrowth in N1 but not in N7 cells. Patch clamp recordings in whole cell configuration showed that, upon adhesion to FN or VN but not to platelet factor 4 (PF4), N1 cells undergo a marked (approximately equal to 20 mV) hyperpolarization of the resting potential (Vrest) that occurred within the first 20 min after cell contact with ECM, and persisted for approximately 1 h before reverting to the time zero values. This hyperpolarization was totally absent in N7 cells. A detailed analysis of the molecular mechanisms involved in N1 and N7 cell adhesion to ECM substrata was performed by using antibodies raised against the FN receptor and synthetic peptides variously competing with the FN or VN binding to integrin receptor (GRGDSP and GRGESP). Antibodies, as well as GRGDSP, abolished adhesion of N1 and N7 clones to FN and VN, revealing a similar implication of integrins in the adhesion of these clones to the ECM proteins. However, these anti-adhesive treatments, while ineffective on Vrest of N7 cells, abolished in N1 cells the FN- or VN-induced hyperpolarization and neurite outgrowth, that appeared therefore strictly associated and integrin-mediated phenomena. The nature of this association was deepened through a comparative analysis of the integrin profiles and the ion channels of N1 and N7 cells. The integrin immunoprecipitation profile resulted very similarly in the two clones, with only minor differences concerning the alpha V containing complexes. Both clones possessed Ca2+ and K+ delayed rectifier (KDR) channels, while only N1 cells were endowed with inward rectifier K+ (KIR) channels. The latter governed the Vrest, and, unlike KDR channels, were blocked by Ba2+ and Cs+. By moving patched cells in contact with FN-coated beads, it was shown that KIR channel activation was responsible for the FN-mediated hyperpolarization of Vrest. Treatment with Pertuxis toxin (PTX) abolished this hyperpolarization and neurite outgrowth, indicating that a G protein is interposed between integrins and KIR channels and that the activation of these channels is required for neuritogenesis. In fact, the block of KIR channels by Cs+ abolished both hyperpolarization and neurite outgrowth, provided that the cation was supplied during the first two hours after N1 cell contact with FN.(ABSTRACT TRUNCATED AT 400 WORDS)


Assuntos
Integrinas/fisiologia , Neuroblastoma/patologia , Canais de Potássio/fisiologia , Potenciais de Ação/fisiologia , Sequência de Aminoácidos , Animais , Bário/farmacologia , Adesão Celular/fisiologia , Diferenciação Celular/fisiologia , Membrana Celular/química , Membrana Celular/fisiologia , Membrana Celular/ultraestrutura , Movimento Celular/fisiologia , Césio/farmacologia , Matriz Extracelular/metabolismo , Matriz Extracelular/fisiologia , Fibronectinas/metabolismo , Proteínas de Ligação ao GTP/fisiologia , Crescimento/efeitos dos fármacos , Camundongos , Dados de Sequência Molecular , Neuritos/fisiologia , Neuritos/ultraestrutura , Neuroblastoma/química , Neuroblastoma/ultraestrutura , Canais de Potássio/efeitos dos fármacos , Transdução de Sinais/fisiologia , Células Tumorais Cultivadas , Fatores de Virulência de Bordetella/farmacologia
15.
Lipids ; 28(8): 727-30, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8377588

RESUMO

To determine which structural characteristics of membrane phospholipids influence adenylate cyclase activity, we measured basal and sodium fluoride-or forskolin-stimulated activity in a murine fibroblast cell line, i.e., Balb/c3T3 cells grown in media supplemented with fetal calf serum (FCS), lipid-depleted FCS (LD-FCS) or LD-FCS complexed with different phosphatidylcholine (PC) molecular species. Cells grown in the presence of LD-FCS showed a substantial decrease in their basal and NaF-stimulated adenylate cyclase activities; however, their forskolin-stimulated activity was not altered, suggesting that the enzyme's catalytic site is not affected by changes in membrane lipids. Media supplemented with different LD-FCS/PC complexes were shown to prevent the LD-FCS-mediated reduction of basal and NaF-stimulated adenylate cyclase activity to different extents. Addition of cis-9-16:1, cis-9-18:1/cis-9-18:1 or cis-9-18:1/cis-9,12-18:2 sn-glycerophosphocholine (GPC) completely restored adenylate cyclase activity, while cis-11-18:1/cis-11-18:1 GPC was not effective and only a partial recovery was observed with 16:0/16:0, 16:0/cis-9-18:1 and trans-9-18:1 GPC. Considering the structural features of these seven PC molecular species, the findings suggest that an optimal lipid environment is conferred to the enzyme by the presence of two cis double bonds, each located in delta 9 position of the PC acyl chains. The limited effect of cis-9-16:1/cis-9-18:1 GPC and cis-9-18:1/cis-9-16:1 GPC suggests that an equal length of the terminal hydrocarbon chains extending beyond the delta 9 double bonds is also important.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Adenilil Ciclases/metabolismo , Fosfatidilcolinas/metabolismo , Células 3T3 , Animais , Colforsina/farmacologia , Lipídeos de Membrana/química , Lipídeos de Membrana/metabolismo , Camundongos , Estrutura Molecular , Fosfatidilcolinas/química , Fosfatidilcolinas/farmacologia , Fluoreto de Sódio/farmacologia
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