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1.
Osteoporos Int ; 29(4): 947-952, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29397409

RESUMEN

The FRAX algorithm assesses the patient's probability of sustaining an osteoporotic fracture and can be calculated with or without densitometric data. This study seeks to determine whether in men, FRAX scores calculated without BMD, correctly identify patients with BMD-defined osteoporosis. INTRODUCTION: The diagnosis of osteoporosis is based on densitometric data, the presence of a fragility fracture or increased fracture risk. The FRAX algorithm estimates the patient's 10-year probability of sustaining an osteoporotic fracture and can be calculated with or without BMD data. The purpose of this study is to determine whether in men, FRAX calculated without BMD, can correctly identify patients with BMD-defined osteoporosis. METHODS: Retrospectively retrieved data from 726 consecutive Caucasian males, 50 to 70 years old referred to our Osteoporosis Center. RESULTS: In the population studied, 11.8 and 25.3% had BMD-defined osteoporosis when female and male reference populations were used respectively. When the National Osteoporosis Foundation thresholds to initiate treatment are used, only 27% of patients with BMD-defined osteoporosis, but 4% with normal BMD reached/exceeded these thresholds. Lowering the threshold increased sensitivity, but decreased specificity. CONCLUSIONS: Our results suggest that FRAX without BMD is not sensitive/specific enough to be used to identify Caucasian men 50 to 70 years old with BMD-defined osteoporosis.


Asunto(s)
Densidad Ósea/fisiología , Osteoporosis/diagnóstico , Anciano , Algoritmos , Densitometría , Cuello Femoral/fisiopatología , Articulación de la Cadera/fisiopatología , Humanos , Vértebras Lumbares/fisiopatología , Masculino , Persona de Mediana Edad , Osteoporosis/fisiopatología , Fracturas Osteoporóticas/etiología , Fracturas Osteoporóticas/fisiopatología , Fracturas Osteoporóticas/prevención & control , Curva ROC , Estudios Retrospectivos , Medición de Riesgo/métodos
2.
J Musculoskelet Neuronal Interact ; 14(1): 124-30, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24583547

RESUMEN

Distraction osteogenesis (DO) is a successful technique for bone lengthening, but one problem is the need to keep an external fixator in place until bone completely regenerates. We hypothesized that the systemic administration of sclerostin antibodies (Scl-Ab) can accelerate bone regeneration in a mouse model of DO. A total of 110 mice were randomized to receive one intravenous injection per week of either Scl-Ab (100 mg per kg body weight) or saline after DO surgery. Mice were sacrificed on day 11, 17, 34 or 51 post-surgery. Microcomputed tomography showed that bone volume per tissue volume of the Scl-Ab treated group was significantly higher on day 11 (P=0.009). Histological examinations indicated that chondrocytes and fibrocartilage predominated in the Scl-Ab group at day 11. The radiographic score of bone healing was also higher in Scl-Ab treated animals at day 11. There was a trend towards higher ultimate force and work to failure in Scl-Ab treated groups on day 34 and 51 (P>0.05). These data suggest the potential utility of Scl-Ab to reduce the time during DO when an external fixator is required.


Asunto(s)
Anticuerpos/farmacología , Regeneración Ósea/efectos de los fármacos , Glicoproteínas/antagonistas & inhibidores , Osteogénesis por Distracción/métodos , Proteínas Adaptadoras Transductoras de Señales , Animales , Modelos Animales de Enfermedad , Péptidos y Proteínas de Señalización Intercelular , Masculino , Ratones
3.
Gerontol Geriatr Med ; 4: 2333721418777057, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-31799336

RESUMEN

Diabetes mellitus is common among older people. Hypoglycemia is a sign of poorly controlled diabetes mellitus and may lead to irritability, agitation, anxiety, hunger, and an excessive food intake, which in turn may make the control of diabetes more difficult. Excessive, inappropriate food intake is also a sign of Fronto-Temporal Dementia (behavioral variant: bvFTD). In this case study, we describe the events leading to an altercation that developed between an older diabetic patient with bvFTD and the staff in an Assisted Living Facility. His first dose of insulin was given early that morning while he was still asleep. He, subsequently, woke up feeling hungry, agitated, and irritable. This, in turn, exacerbated the hyperorality associated with bvFTD. We examine what went wrong in the patient/caregiver interaction and how this potentially catastrophic situation could have been avoided or defused.

4.
Gerontol Geriatr Med ; 4: 2333721417740190, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29468186

RESUMEN

Repetitive questioning is a major problem for caregivers, particularly taxing if they are unable to recognize and understand the reasons why their loved one keeps asking the same question over and over again. Caregivers may be tempted to believe that the patient does not even try to remember the answer given or is just getting obnoxious. This is incorrect. Repetitive questioning is due to the underlying disease: The patient's short term memory is impaired and he is unable to register, encode, retain and retrieve the answer. If he is concerned about a particular topic, he will keep asking the same question over and over again. To the patient each time she asks the question, it is as if she asked it for the first time. Just answering repetitive questioning by providing repeatedly the same answer is not sufficient. Caregivers should try to identify the underlying cause for this repetitive questioning. In an earlier case study, the patient was concerned about her and her family's safety and kept asking whether the doors are locked. In this present case study, the patient does not know how to handle the awkward situation he finds himself in. He just does not know what to do. He is not able to adjust to the new unexpected situation. So he repeatedly wants to reassure himself that he is not intruding by asking the same question over and over again. We discuss how the patient's son-in-law could have avoided this situation and averted the catastrophic ending.

5.
Gerontol Geriatr Med ; 4: 2333721417738915, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29349099

RESUMEN

Repetitive questioning is due to an impaired episodic memory and is a frequent, often presenting, problem in patients with Alzheimer's disease (amnestic type). It is due to the patients' difficulties learning new information, retaining it, and recalling it, and is often aggravated by a poor attention span and easy distractibility. A number of factors may trigger and maintain repetitive questioning. Caregivers should try to identify and address these triggers. In the case discussion presented, it is due to the patient's concerns about her and her family's safety triggered by watching a particularly violent movie aired on TV. What went wrong in the patient/caregiver interaction and how it could have been avoided or averted are explored. Also reviewed are the impact of repetitive questioning, the challenges it raises for caregivers, and some effective intervention strategies that may be useful to diffuse the angst that caregivers experience with repetitive questioning.

6.
Gerontol Geriatr Med ; 4: 2333721418777085, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29900187

RESUMEN

Driving is a symbol of autonomy and independence, eagerly awaited during adolescence, cherished during adulthood and reluctantly rescinded during old age. It is nevertheless an individual's privilege, not right, especially as driving may affect other drivers and pedestrians on the road. It is therefore not only the individual patient who is at stake but essentially the entire community. In this case scenario, we describe the situation that arose when a patient with multi-infarct dementia wanted to go for a drive and his son and grandson tried to convince him that he could no longer drive. What went wrong in the caregivers/patient interaction is presented. The futility of arguing with patients who have dementia is highlighted as well as the suspiciousness it may generate. Alternate actions that can be useful to avoid/avert the situation from escalating and having a catastrophic ending are discussed. Testing/evaluating patients with dementia for fitness to drive is also reviewed and a list of select resources is included.

7.
Gerontol Geriatr Med ; 4: 2333721418778419, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29900188

RESUMEN

Patients with dementia, particularly Alzheimer's disease, may not recognize that their clothes are dirty. They may see the food stains and discoloration of the clothes and yet because of their agnosia are unable to integrate these observations and deduce that their clothes are dirty and need to be changed. They will, therefore, resist attempts to get them to change clothes, especially if these clothes happen to be their favorite ones. This often causes caregivers to become frustrated, especially, if it represents a change in the patient's previous habits of only wearing clean clothes. In this case study, we present a 72-year-old woman with moderate Alzheimer's disease who lives with her daughter, who adamantly refuses to change the clothes she has been wearing for a few days and which are now clearly dirty. We report the interaction, highlight what went wrong in the patient-daughter interaction, and discuss how the catastrophic ending could have been avoided or averted.

8.
Gerontol Geriatr Med ; 4: 2333721418778421, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29900189

RESUMEN

Insomnia is a common problem in older people, especially in patients with mild cognitive impairment (MCI) whose circadian rhythm is often compromised. Insomnia exerts such a toll on caregivers that it is frequently the primary reason for seeking to institutionalize their loved ones. Three different types of insomnia are recognized: sleep-onset or initial insomnia, sleep maintenance or middle insomnia, and early morning awakening or late insomnia. Nocturnal hypoglycemia, as a cause of middle insomnia, is the main focus of this case study. Other types of insomnia are also briefly reviewed. The management of insomnia is then discussed including sleep hygiene, the usefulness and potential drawbacks of dietary supplements, nonprescription over-the-counter preparations and prescription hypnotics. Sleep architecture is then briefly reviewed, emphasizing the importance of its integrity and the role of each sleep stage.

9.
Gerontol Geriatr Med ; 4: 2333721418777086, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29872665

RESUMEN

Visual well-formed hallucinations, fluctuations in the level of cognition, and alertness and extrapyramidal signs are core features of dementia with Lewy bodies. Some patients realize that what they are seeing or hearing are just hallucinations and learn to accept them. Others, however experience these hallucinations as quite real and cannot be dissuaded from the firm belief that they are. In fact, efforts to dissuade them often serve only to confirm the often associated paranoid delusions and this may lead to a catastrophic ending. Hence, it is best not to contradict the patient. Instead, attempts should be made to distract the patient and change the focus of her or his attention. In this case scenario, we present a 68-year-old man who has been diagnosed with dementia with Lewy bodies. He lives with his daughter. He has visual hallucinations and paranoid delusions that worsen at night: He thinks there are people outside the house plotting to kill him. We discuss what went wrong in the patient/caregiver interaction and how the catastrophic ending could have been avoided or averted.

10.
Bone Joint Res ; 7(6): 397-405, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30034793

RESUMEN

OBJECTIVES: Bone fracture healing is regulated by a series of complex physicochemical and biochemical processes. One of these processes is bone mineralization, which is vital for normal bone development. Phosphatase, orphan 1 (PHOSPHO1), a skeletal tissue-specific phosphatase, has been shown to be involved in the mineralization of the extracellular matrix and to maintain the structural integrity of bone. In this study, we examined how PHOSPHO1 deficiency might affect the healing and quality of fracture callus in mice. METHODS: Tibial fractures were created and then stabilized in control wild-type (WT) and Phospho1-/- mice (n = 16 for each group; mixed gender, each group carrying equal number of male and female mice) at eight weeks of age. Fractures were allowed to heal for four weeks and then the mice were euthanized and their tibias analyzed using radiographs, micro-CT (µCT), histology, histomorphometry and three-point bending tests. RESULTS: The µCT and radiographic analyses revealed a mild reduction of bone volume in Phospho1-/- callus, although it was not statistically significant. An increase in trabecular number and a decrease in trabecular thickness and separation were observed in Phospho1-/- callus in comparison with the WT callus. Histomorphometric analyses showed that there was a marked increase of osteoid volume over bone volume in the Phospho1-/- callus. The three-point bending test showed that Phospho1-/- fractured bone had more of an elastic characteristic than the WT bone. CONCLUSION: Our work suggests that PHOSPHO1 plays an integral role during bone fracture repair and may be a therapeutic target to improve the fracture healing process.Cite this article: M. W. Morcos, H. Al-Jallad, J. Li, C. Farquharson, J. L. Millán, R. C. Hamdy, M. Murshed. PHOSPHO1 is essential for normal bone fracture healing: An Animal Study. Bone Joint Res 2018;7:397-405. DOI: 10.1302/2046-3758.76.BJR-2017-0140.R2.

11.
Heliyon ; 3(11): e00450, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29167826

RESUMEN

Several types of serious bone defects would not heal without invasive clinical intervention. One approach to such defects is to enhance the capacity of bone-formation cells. Exogenous bone morphogenetic proteins (BMP) have been utilized to positively regulate matrix mineralization and osteoblastogenesis, however, numerous adverse effects are associated with this approach. Noggin, a potent antagonist of BMPs, is an ideal candidate to target and decrease the need for supraphysiological doses of BMPs. In the current research we report a novel siRNA-mediated gene knock-down strategy to down-regulate Noggin. We utilized a lipid nanoparticle (LNP) delivery strategy in pre-osteoblastic rat cells. In vitro LNP-siRNA treatment caused inconsequential cell toxicity and transfection was achieved in over 85% of cells. Noggin siRNA treatment successfully down-regulated cellular Noggin protein levels and enhanced BMP signal activity which in turn resulted in significantly increased osteoblast differentiation and extracellular matrix mineralization evidenced by histological assessments. Gene expression analysis showed that targeting Noggin specifically in bone cells would not lead to a compensatory effect from other BMP negative regulators such as Gremlin and Chordin. The results from this study support the notion that novel therapeutics targeting Noggin have the clinically relevant potential to enhance bone formation without the need for toxic doses of exogenous BMPs. Such treatments will undeniably provide safe and economical treatments for individuals whose poor bone repair results in permanent morbidity and disability.

12.
Gerontol Geriatr Med ; 3: 2333721417720585, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28904992

RESUMEN

Choices are often difficult to make by patients with Alzheimer Dementia. They often become acutely confused when faced with too many options because they are not able to retain in their working memory enough information about the various individual choices available. In this case study, we describe how an essentially simple benign task (choosing a dress to wear) can rapidly escalate and result in a catastrophic outcome. We examine what went wrong in the patient/caregiver interaction and how that potentially catastrophic situation could have been avoided or defused.

13.
Gerontol Geriatr Med ; 3: 2333721417734684, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29051913

RESUMEN

Patients with dementia, especially Alzheimer's disease and particularly those in early stages, are susceptible to become victims of predators: Their agnosia (see Case 1) prevents them from detecting and accurately interpreting subtle signals that otherwise would have alerted them that they are about to fall for a scam. Furthermore, their judgment is impaired very early in the disease process, often before other symptoms manifest themselves and usually before a diagnosis is made. Patients with early stages of dementia are therefore prime targets for unscrupulous predators, and it behooves caregivers and health care professionals to ensure the integrity of these patients. In this case study, we discuss how a man with mild Alzheimer's disease was about to fall for a scam were it not for his vigilant wife. We discuss what went wrong in the patient/caregiver interaction and how the catastrophic ending could have been avoided or averted.

14.
Gerontol Geriatr Med ; 3: 2333721417721108, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29164172

RESUMEN

In this case study, we present a patient with preexistent posttraumatic stress disorder and psychosis who has been recently diagnosed with Dementia with Lewy Bodies. He is experiencing vivid hallucinations. What went wrong between him and his wife as a result of these hallucinations is presented. Alternative actions that could have been used are suggested. OBJECTIVES: At the end of this case study, readers will know the following:The characteristic clinical features of Dementia with Lewy Bodies (DLB).Patients experiencing hallucinations should not be contradicted, to them, these hallucinations are real.Easy distractibility and short attention span can be exploited to avert or defuse potentially catastrophic situations.Patients with dementia should not have access to loaded guns.

15.
Gerontol Geriatr Med ; 3: 2333721417735938, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29242811

RESUMEN

Mild cognitive impairment (MCI) is the middle ground between normal, age-appropriate memory impairment, and dementia. Whereas patients with MCI are able to cope with the memory deficit, those with dementia are not: Their memory impairment and other cognitive deficits are of sufficient magnitude to interfere with the patients' ability to cope independently with daily activities. In both MCI and dementia, there is evidence of declining cognitive functions from a previously higher level of functioning. In both the conditions, there is also an evidence of dysfunction in one or more cognitive domains. There are two subtypes of MCI depending on whether memory is predominantly affected: amnestic type and nonamnestic/behavioral type. Not all patients with MCI transition to dementia, some recover. In this case scenario, we present a 68-year-old man with MCI who lives with his wife. They are getting ready to host dinner. His wife asks him to vacuum the dining room while she runs an urgent errand. We describe how this simple task vacuuming a room ended in a catastrophe with the patient spending the night in jail and his wife hospitalized. We discuss what went wrong in the patient/wife interaction and how the catastrophic ending could have been avoided. OBJECTIVES: At the end of this case discussion readers will know the following:The differences between mild cognitive impairment (MCI), normal aging, and dementia.MCI is often a precursor of dementia and has an amnestic or nonamnestic/behavioral presentation. However, not all patients with MCI develop dementia, some even recover.MCI is an opportunity to discuss with the patient various issues that may arise, should it progress to dementia such as preparing a will, transitioning from driver to passenger, and addressing various financial and legal issues including end-of-life issues and selecting someone to have power of attorney.Patients with MCI should be regularly followed up to determine whether and when they will transition to dementia as this changes the level of care needed.Patients with MCI are at an increased risk of triggering accidents because of their cognitive impairment and often impaired judgment.It may be hazardous to leave patients with MCI alone, without supervision.The importance of support groups, social media, and cameras when providing care to patients with MCI and dementias.

16.
Biochim Biophys Acta ; 1357(2): 209-14, 1997 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-9223624

RESUMEN

Thrombospondin-1 (TSP-1) is synthesized, secreted, and incorporated into the extracellular matrix by a variety of cells, including the endothelial cells. Addition of angiotensin II (AII) significantly induced TSP-1 mRNA in rat heart-derived endothelial cells. TSP-1 mRNA levels reached a plateau within 2 h after the addition of AII and decreased after 5 h. The induction was superinduced by cycloheximide and blocked by actinomycin D. Losartan, an AT1 receptor antagonist, could abolish the induction of TSP-1 mRNA by AII. Phorbol 12-myristate 13-acetate (TPA) was found to enhance TSP-1 mRNA level whereas a protein kinase C inhibitor, H7, was shown to block the induction. Immunoblot analysis revealed that TSP-1 was detectable in the medium 4 h after AII stimulation. Our results suggest that the upregulation of TSP-1 by AII represents an important mechanism leading to perivascular fibrosis in the heart.


Asunto(s)
Angiotensina II/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Glicoproteínas de Membrana/genética , Miocardio/metabolismo , 1-(5-Isoquinolinesulfonil)-2-Metilpiperazina/farmacología , Antagonistas de Receptores de Angiotensina , Animales , Compuestos de Bifenilo/farmacología , Northern Blotting , Línea Celular , Cicloheximida/farmacología , Dactinomicina/farmacología , Endotelio/metabolismo , Inhibidores Enzimáticos/farmacología , Imidazoles/farmacología , Losartán , Glicoproteínas de Membrana/biosíntesis , Proteína Quinasa C/antagonistas & inhibidores , Proteína Quinasa C/metabolismo , Piridinas/farmacología , Ratas , Tetrazoles/farmacología , Trombospondinas
17.
Biochim Biophys Acta ; 1313(1): 1-5, 1996 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-8781542

RESUMEN

Thromboxane A2 (TXA2) and ET-1 have been known to play important roles in modulating vascular contraction and growth. The present study was undertaken to examine the effect of TXA2 on the induction of endothelin-1 (ET-1) mRNA and protein levels in smooth muscle cells derived from rat heart. U-46619, a stable TXA2 mimetic, superinduced preproET-1 mRNA in the presence of cycloheximide in these cells. This effect could be blocked by SQ-29548, a TXA2/prostaglandin H2 receptor antagonist and by actinomycin D, and RNA synthesis inhibitor. In addition, H7, a protein kinase C inhibitor, could abolish the induction. Transient transfection experiment revealed that the elevated ET-1 mRNA level after U-46619 treatment was a result of the activation of ET-1 gene activity. The elevated ET-1 message level was accompanied by increased ET-1 release into the cultured medium. These results show that the short-lived TXA2 can induce potent and long-lived ET-1. These findings support a potential role for ET-1 in the pathogenesis of coronary atherosclerosis and hypertension evoked by TXA2.


Asunto(s)
Endotelinas/biosíntesis , Músculo Liso/metabolismo , Tromboxano A2/fisiología , 1-(5-Isoquinolinesulfonil)-2-Metilpiperazina , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico , Animales , Compuestos Bicíclicos Heterocíclicos con Puentes , Células Cultivadas , Endotelinas/genética , Ácidos Grasos Insaturados , Expresión Génica/efectos de los fármacos , Hidrazinas/farmacología , Isoquinolinas/farmacología , Miocardio/citología , Piperazinas/farmacología , Regiones Promotoras Genéticas , Endoperóxidos de Prostaglandinas Sintéticos/farmacología , Proteína Quinasa C/antagonistas & inhibidores , Proteína Quinasa C/fisiología , ARN Mensajero/genética , Ratas , Receptores de Tromboxanos/antagonistas & inhibidores , Receptores de Tromboxanos/fisiología , Tromboxano A2/análogos & derivados , Tromboxano A2/farmacología
18.
Biochim Biophys Acta ; 1497(1): 69-76, 2000 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-10838160

RESUMEN

Transforming growth factor-beta1 (TGF-beta1), an abundant growth factor in bone matrix, has been shown to be involved in bone formation and fracture healing. The mechanism of action of the osteogenic effect of TGF-beta1 is not clearly understood. In this study, we found that the addition of TGF-beta1 to murine osteoblastic MC3T3-E1 cells induced vascular endothelial growth factor (VEGF) mRNA production. VEGF mRNA levels reached a plateau within 2 h after the addition of TGF-beta1. The induction was superinduced by cycloheximide and blocked by actinomycin D. Ro 31-8220, a protein kinase C inhibitor, abrogated the induction. In addition, curcumin, an inhibitor for transcription factor AP-1, also blocked the induction. Electrophoretic mobility shift assay revealed an enhanced binding of transcription factors AP-1 and NF-kappaB. Transient transfection experiment showed that VEGF promoter activity increased 3.6-fold upon TGF-beta1 stimulation. Immunoblot analysis showed that the amount of secreted VEGF was elevated in the medium 4 h after TGF-beta1 stimulation. Our results therefore suggest that at least part of the osteogenic activity of TGF-beta1 may be attributed to the production of VEGF.


Asunto(s)
Factores de Crecimiento Endotelial/genética , Linfocinas/genética , Osteoblastos/efectos de los fármacos , Factor de Crecimiento Transformador beta/farmacología , Animales , Western Blotting , Línea Celular , Curcumina/farmacología , Cicloheximida/farmacología , Dactinomicina/farmacología , Factores de Crecimiento Endotelial/metabolismo , Inhibidores Enzimáticos/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Indoles/farmacología , Luciferasas/genética , Luciferasas/metabolismo , Linfocinas/metabolismo , Ratones , FN-kappa B/efectos de los fármacos , FN-kappa B/metabolismo , Osteoblastos/citología , Osteoblastos/metabolismo , Regiones Promotoras Genéticas/genética , Proteína Quinasa C/antagonistas & inhibidores , ARN Mensajero/efectos de los fármacos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Factores de Tiempo , Factor de Transcripción AP-1/efectos de los fármacos , Factor de Transcripción AP-1/metabolismo , Factor A de Crecimiento Endotelial Vascular , Factores de Crecimiento Endotelial Vascular
19.
Biochim Biophys Acta ; 1405(1-3): 29-34, 1998 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-9784597

RESUMEN

Addition of lysophosphatidic acid (LPA) to rat aorta-derived endothelial cells significantly induced preproendothelin-1 (preproET-1) mRNA expression. PreproET-1 mRNA levels reached a plateau within 1 h after the addition of 0.5 microM LPA and declined after 2 h. The induction was superinduced by cycloheximide and was blocked by actinomycin D. Suramin, an LPA receptor antagonist, abolished the induction of preproET-1 mRNA by LPA. Protein kinase C inhibitors, H7 and bisindolylmaleimide, were able to block the induction. Transient transfection experiment revealed that the elevated preproET-1 mRNA was a result of the activation of ET-1 gene activity. Electrophoretic mobility shift assay revealed that LPA stimulated the binding of AP-1. The secreted level of ET-1 was elevated 2.3-fold after 12 h of stimulation with LPA. Our results suggest that the upregulation of preproET-1 by LPA may serve to augment and prolong the vasoconstriction action of LPA.


Asunto(s)
Endotelina-1/biosíntesis , Endotelina-1/genética , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/metabolismo , Lisofosfolípidos/farmacología , 1-(5-Isoquinolinesulfonil)-2-Metilpiperazina/farmacología , Animales , Células Cultivadas , Endotelinas/genética , Inhibidores Enzimáticos/farmacología , Indoles/farmacología , Maleimidas/farmacología , Proteína Quinasa C/antagonistas & inhibidores , Precursores de Proteínas/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Factor de Transcripción AP-1/metabolismo , Regulación hacia Arriba/efectos de los fármacos , Vasoconstricción/efectos de los fármacos
20.
Biochim Biophys Acta ; 1401(2): 187-94, 1998 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-9531974

RESUMEN

Vascular endothelial growth factor (VEGF) is a potent mitogen for endothelial cells and a vascular permeability factor. In this study we found that the addition of angiotensin II (AII) to rat heart endothelial cells induced VEGF mRNA production. VEGF mRNA levels reached a plateau within 2 h after the addition of AII and decreased after 4 h. The induction was superinduced by cycloheximide and blocked by actinomycin D. Losartan, an AT1 receptor antagonist, abolished the induction of VEGF mRNA by AII, whereas PD 123319, an AT2 receptor antagonist, had no effect on VEGF mRNA induction. H7, a protein kinase C inhibitor, blocked the induction. RT-PCR experiments showed two mRNA species (VEGF 120 and VEGF 164) in these cells and both species were stimulated by AII. Transient transfection experiment showed that VEGF promoter activity was increased 2.2-fold upon AII stimulation. Electrophoretic mobility shift assay revealed an enhanced binding of transcription factors AP-1 and NF-kappa B. Immunoblot analysis showed that the amount of secreted VEGF was elevated in the medium 8 h after AII stimulation. Our results demonstrate for the first time that the upregulation of VEGF by AII may play a significant role in AII-induced hyperpermeability.


Asunto(s)
Angiotensina II/farmacología , Factores de Crecimiento Endotelial/análisis , Factores de Crecimiento Endotelial/fisiología , Endotelio Vascular/citología , Linfocinas/análisis , Linfocinas/efectos de los fármacos , Linfocinas/fisiología , Vasoconstrictores/farmacología , 1-(5-Isoquinolinesulfonil)-2-Metilpiperazina/análogos & derivados , 1-(5-Isoquinolinesulfonil)-2-Metilpiperazina/farmacología , Angiotensina II/administración & dosificación , Animales , Antihipertensivos/farmacología , Northern Blotting , Bovinos , Medios de Cultivo Condicionados/análisis , Medios de Cultivo Condicionados/química , Cicloheximida/farmacología , Dactinomicina/farmacología , Relación Dosis-Respuesta a Droga , Factores de Crecimiento Endotelial/genética , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/metabolismo , Inhibidores Enzimáticos/farmacología , Imidazoles/farmacología , Immunoblotting , Losartán/farmacología , Linfocinas/genética , Inhibidores de la Síntesis del Ácido Nucleico/farmacología , Proteína Quinasa C/antagonistas & inhibidores , Inhibidores de la Síntesis de la Proteína/farmacología , Piridinas/farmacología , ARN Mensajero/análisis , ARN Mensajero/efectos de los fármacos , Ratas , Factores de Transcripción/efectos de los fármacos , Activación Transcripcional/efectos de los fármacos , Regulación hacia Arriba , Factor A de Crecimiento Endotelial Vascular , Factores de Crecimiento Endotelial Vascular , Vasoconstrictores/administración & dosificación
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