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1.
Arthrosc Sports Med Rehabil ; 4(5): e1721-e1729, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36312706

RESUMO

Purpose: To evaluate outcomes of hip arthroscopy in patients with global acetabular retroversion and to identify correlations between sex, radiographic measurements, athlete status, and return to play with patient-reported outcomes (PROs). Methods: Retrospective study of patients with global acetabular retroversion who underwent arthroscopic femoroacetabular impingement (FAI) surgery was performed. Global acetabular retroversion was defined by 3 criteria: the crossover sign, ischial spine sign, and posterior wall sign on an anteroposterior (AP) pelvic radiograph. Radiographs were used to measure lateral center edge angle, alpha angle, and anterior and posterior wall indices. Femoral version was measured with 3-dimensional computed tomography. Demographics included age, gender, athlete status, return to play, and reoperation. PROs included modified Harris Hip Score, Hip Outcome Score (HOS), Hip Disability and Osteoarthritis Outcome Score, visual analog scale (VAS), and Veterans RAND-12. Spearman correlation determined correlation with perioperative PROs. Generalized estimating equation determined independent predictors. Significance was set at P = .05. Results: From 2013 to 2019, 149 patients (65.0% female) with 160 hips with FAI and global acetabular retroversion underwent hip arthroscopy. Follow-up averaged 29.6 months. All PROs demonstrated significant improvement with the exception of the Veterans RAND-12 Mental. Female patients scored significantly lower on most postoperative PROs and had greater VAS scores (P = .0002-0.0402). A greater proportion of male subjects met the minimum clinically important difference for the modified Harris Hip Score (88.00% vs 78.79%) Low femoral version correlated with greater HOS ADL, HOS Sport, and Hip Disability and Osteoarthritis Outcome Score Sport scores (P = .0077-0.0177). Athletes reported lower preoperative VAS scores, and higher perioperative scores in multiple PROs (P = .0004-0.0486). Nine hips (5.63%) underwent reoperation. Conclusions: Patients with global acetabular retroversion and FAI undergoing hip arthroscopy report good outcomes at short-term follow-up. Male subjects and athletes had superior outcomes compared to female subjects and nonathletes. Radiographic measurements did not correlate with outcomes with exception of low femoral version. Athletes reported lower preoperative pain scores and greater postoperative PROs than nonathletes. Level of Evidence: Level IV, therapeutic case series.

2.
Am J Med Qual ; 37(1): 65-71, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34108393

RESUMO

Resuming elective surgery amid shortages of rapid severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) tests and personal protective equipment, while protecting patient and staff safety, posed a challenge at the study institution. Many hospital systems implemented testing of all presurgical patients, using results from tests performed 3 or more days prior to surgery. Among asymptomatic persons, the percent positive rates of coronavirus disease 2019 (COVID-19) tests in the region did not appear to justify this practice. Instead of universal preoperative COVID-19 testing, the authors elected to mitigate risk by implementing a preoperative program including 14 days of recommended patient self-quarantine and social distancing. For those unable to complete this program and for those undergoing high-risk, aerosol-generating procedures, targeted rapid polymerase chain reaction testing within 2 days of surgery was performed. Data from the initial 4 months suggests that this approach was noninferior to universal preoperative testing with regard to postoperative COVID-19 detection and patient exposure-related COVID-19 cases among hospital staff.


Assuntos
COVID-19 , SARS-CoV-2 , Teste para COVID-19 , Procedimentos Cirúrgicos Eletivos , Humanos , Técnicas de Diagnóstico Molecular
3.
Int J Surg Pathol ; 28(2): 210-215, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31514589

RESUMO

Mammary Paget's disease is rare and comprises about 0.62% of all breast cancer cases, only 1.65% of which occur in male patients. This case report involves a 76-year-old man who presented to his primary care physician with an itching, scaly, unilateral lesion involving the nipple skin. He underwent wide local excision of the lesion for a diagnosis of Bowen's disease (squamous cell carcinoma in situ). Histologic examination of the specimen revealed mammary Paget's disease with ductal carcinoma in situ in the underlying breast tissue. A panel of immunohistochemical stains revealed the Paget cells to be positive for cytokeratin 7, MUC1, GATA3, and androgen receptor and negative for cytokeratins 5/6, p63, SOX10, and MART-1/Melan-A. Paget cells were also negative for estrogen receptor and progesterone receptor, and positive for HER2/neu. However, the underlying ductal carcinoma in situ was positive for both estrogen receptor and progesterone receptor and negative for HER2/neu. This discordance, supported by the current literature, suggests an alternative etiology for Paget's disease in certain cases that cannot be explained by the well-established epidermotropic and transformative theories of Paget's disease evolution.


Assuntos
Neoplasias da Mama Masculina/patologia , Doença de Paget Mamária/patologia , Idoso , Biomarcadores Tumorais/análise , Neoplasias da Mama Masculina/metabolismo , Humanos , Imuno-Histoquímica , Masculino , Doença de Paget Mamária/metabolismo
4.
Br J Surg ; 104(10): 1372-1381, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28632890

RESUMO

BACKGROUND: A critical appraisal of the benefits of minimally invasive surgery (MIS) is needed, but is lacking. This study examined the associations between MIS and 30-day postoperative outcomes including complications graded according to the Clavien-Dindo classification, unplanned readmissions, hospital stay and mortality for five common surgical procedures. METHODS: Patients undergoing appendicectomy, colectomy, inguinal hernia repair, hysterectomy and prostatectomy were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Non-parsimonious propensity score methods were used to construct procedure-specific matched-pair cohorts that reduced baseline differences between patients who underwent MIS and those who did not. Bonferroni correction for multiple comparisons was applied and P < 0·006 was considered significant. RESULTS: Of the 532 287 patients identified, 53·8 per cent underwent MIS. Propensity score matching yielded an overall sample of 327 736 patients (appendicectomy 46 688, colectomy 152 114, inguinal hernia repair 59 066, hysterectomy 59 066, prostatectomy 10 802). Within the procedure-specific matched pairs, MIS was associated with significantly lower odds of Clavien-Dindo grade I-II, III and IV complications (P ≤ 0·004), unplanned readmissions (P < 0·001) and reduced hospital stay (P < 0·001) in four of the five procedures studied, with the exception of inguinal hernia repair. The odds of death were lower in patients undergoing MIS colectomy (P < 0·001), hysterectomy (P = 0·002) and appendicectomy (P = 0·002). CONCLUSION: MIS was associated with significantly fewer 30-day postoperative complications, unplanned readmissions and deaths, as well as shorter hospital stay, in patients undergoing colectomy, prostatectomy, hysterectomy or appendicectomy. No benefits were noted for inguinal hernia repair.


Assuntos
Procedimentos Cirúrgicos Minimamente Invasivos/efeitos adversos , Readmissão do Paciente , Complicações Pós-Operatórias/mortalidade , Apendicectomia/efeitos adversos , Apendicectomia/economia , Colectomia/efeitos adversos , Colectomia/economia , Gastos em Saúde , Herniorrafia/efeitos adversos , Herniorrafia/economia , Humanos , Histerectomia/efeitos adversos , Histerectomia/economia , Procedimentos Cirúrgicos Minimamente Invasivos/economia , Readmissão do Paciente/economia , Complicações Pós-Operatórias/economia , Pontuação de Propensão , Prostatectomia/efeitos adversos , Prostatectomia/economia , Resultado do Tratamento , Estados Unidos
5.
J Pediatr Urol ; 12(5): 313.e1-313.e2, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27687533

RESUMO

INTRODUCTION: Bladder augmentation is a common surgical intervention for neuropathic bladder dysfunction, and has conventionally been an open procedure. We present a robotic ileocystoplasty to demonstrate the feasibility of an entirely intracorporeal approach in a pediatric patient. METHODS: The patient was a 6 year old (18.5 kg) boy with a neurogenic bladder secondary to lumbar myelomeningocele. Urodynamics revealed a small capacity and poorly compliant bladder and he was incontinent between frequent catheterizations. A robotic augmentation cystoplasty was performed. RESULTS: At one-month postoperatively, a cystogram revealed no urine leak, and the suprapubic tube was removed. The patient resumed CIC every 3 h during the day and once overnight until postoperative urodynamic studies confirmed safe dynamics, after which the CIC interval was lengthened. CONCLUSION: Robotic bladder augmentation is safe and feasible in a select pediatric population. The entire procedure including preparation of the bowel segment can be completed intracorporeally, even in smaller children.


Assuntos
Laparoscopia , Procedimentos Cirúrgicos Robóticos , Bexiga Urinaria Neurogênica/cirurgia , Bexiga Urinária/cirurgia , Criança , Humanos , Masculino , Procedimentos Cirúrgicos Urológicos/métodos
6.
Arthrosc Tech ; 5(6): e1215-e1220, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28149716

RESUMO

Minimally invasive percutaneous radiofrequency ablation (RFA) techniques are the standard of care for treating simple osteoid osteomas (OOs). Historically, OOs were treated with open en bloc resection or curettage of the nidus. RFA procedures have been linked to soft-tissue complications of varying severity. In addition, RFA may be a poor choice for periarticular OOs because of the potential for procedure-related articular cartilage damage. Hip arthroscopy is a widely accepted approach for the treatment of femoroacetabular impingement. We describe arthroscopic resection of an acetabular rim-based OO as part of a rim resection and labral repair. Early clinical follow-up suggests that arthroscopic resection of an OO in this unusual location is precise and predictable, allows for an additional evaluation of associated symptomatic pathology (i.e., femoroacetabular impingement), and results in prompt symptom resolution.

7.
Int J Biochem Cell Biol ; 68: 59-69, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26315281

RESUMO

The epithelium of asthmatics is characterized by reduced expression of E-cadherin and increased expression of the basal cell markers ck-5 and p63 that is indicative of a relatively undifferentiated repairing epithelium. This phenotype correlates with increased proliferation, compromised wound healing and an enhanced capacity to undergo epithelial-mesenchymal transition (EMT). The transcription factor ß-catenin plays a vital role in epithelial cell differentiation and regeneration, depending on the co-factor recruited. Transcriptional programs driven by the ß-catenin/CBP axis are critical for maintaining an undifferentiated and proliferative state, whereas the ß-catenin/p300 axis is associated with cell differentiation. We hypothesized that disrupting the ß-catenin/CBP signaling axis would promote epithelial differentiation and inhibit EMT. We treated monolayer cultures of human airway epithelial cells with TGFß1 in the presence or absence of the selective small molecule ICG-001 to inhibit ß-catenin/CBP signaling. We used western blots to assess expression of an EMT signature, CBP, p300, ß-catenin, fibronectin and ITGß1 and scratch wound assays to assess epithelial cell migration. Snai-1 and -2 expressions were determined using q-PCR. Exposure to TGFß1 induced EMT, characterized by reduced E-cadherin expression with increased expression of α-smooth muscle actin and EDA-fibronectin. Either co-treatment or therapeutic administration of ICG-001 completely inhibited TGFß1-induced EMT. ICG-001 also reduced the expression of ck-5 and -19 independent of TGFß1. Exposure to ICG-001 significantly inhibited epithelial cell proliferation and migration, coincident with a down regulation of ITGß1 and fibronectin expression. These data support our hypothesis that modulating the ß-catenin/CBP signaling axis plays a key role in epithelial plasticity and function.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Células Epiteliais/metabolismo , Fragmentos de Peptídeos/genética , Pirimidinonas/farmacologia , Sialoglicoproteínas/genética , Fator de Crescimento Transformador beta1/farmacologia , beta Catenina/genética , Actinas/genética , Actinas/metabolismo , Asma/genética , Asma/metabolismo , Asma/patologia , Diferenciação Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Proteína p300 Associada a E1A/genética , Proteína p300 Associada a E1A/metabolismo , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Fibronectinas/genética , Fibronectinas/metabolismo , Regulação da Expressão Gênica , Humanos , Queratina-19/genética , Queratina-19/metabolismo , Queratina-5/genética , Queratina-5/metabolismo , Fragmentos de Peptídeos/antagonistas & inibidores , Fragmentos de Peptídeos/metabolismo , Cultura Primária de Células , Mucosa Respiratória/citologia , Mucosa Respiratória/efeitos dos fármacos , Mucosa Respiratória/metabolismo , Sialoglicoproteínas/antagonistas & inibidores , Sialoglicoproteínas/metabolismo , Transdução de Sinais , Fatores de Transcrição da Família Snail , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Fator de Crescimento Transformador beta1/antagonistas & inibidores , beta Catenina/antagonistas & inibidores , beta Catenina/metabolismo
9.
J Neurochem ; 66(4): 1432-9, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8627295

RESUMO

Myelin gene expression was investigated in the immortalized S16 Schwann cell line grown in the presence and absence of serum and at different densities. Protein expression was monitored by western blotting, and message levels were determined by RNase protection assays. To study cell proliferation rates at different cell densities and serum conditions, [3H]thymidine uptake assays and cell counts were performed. Although serum deprivation decreased cell proliferation as expected, the proliferation of S16 cells was unchanged or slightly increased at high density under the conditions of our experiments in either serum-containing or serum-free medium. This increased cell division at high density appeared to be due to greater release of an autocrine growth factor to the medium by dense cell populations. For both sparse and dense cells, substantially more P0 glycoprotein (P0) and myelin-associated glycoprotein (MAG) per milligram of total cellular protein were expressed when the cells were proliferating slowly in defined medium in comparison with more rapidly proliferating cells in serum-containing medium. Furthermore, in both serum-containing and defined media, dense cell populations expressed more MAG and PO than sparse ones. PO mRNa and MAG mRNA levels generally paralleled protein levels. The level of mRNA for peripheral myelin protein-22 (PMP-22) was also increased at high cell density but did not change much when proliferation was decreased by serum deprivation. PMP-22 protein was not detected under any of the growth conditions. The changes in expression of these genes with growth conditions may be specific for myelin proteins, because the expression of a nonmyelin glycoprotein, L1, remained constant. The level of cyclic AMP in the cells did not change with the different growth conditions tested. The results indicate that the S16 Schwann cell line mimics primary or secondary Schwann cells by down-regulating myelin gene expression when it proliferates more rapidly in the presence of serum. Furthermore, in both the presence and absence of serum, there was greater expression of myelin genes at high cell density that was not associated with a decreased proliferative rate. Because evidence for a role of secretory factors in affecting myelin gene expression was not obtained by treating sparse S16 cells with medium conditioned by dense S16 cells, the results suggest that the higher expression of myelin genes at high density may be mediated by cell-to-cell contact.


Assuntos
Proteínas da Mielina/genética , Células de Schwann/fisiologia , Animais , Sequência de Bases , Proteínas Sanguíneas/farmacologia , Contagem de Células , Divisão Celular/fisiologia , Linhagem Celular Transformada/citologia , Linhagem Celular Transformada/fisiologia , Meios de Cultivo Condicionados , AMP Cíclico/metabolismo , Galactosilceramidas/genética , Expressão Gênica/fisiologia , Dados de Sequência Molecular , Proteína P0 da Mielina/genética , Glicoproteína Associada a Mielina/genética , RNA Mensageiro/análise , Ratos , Células de Schwann/citologia , Sulfoglicoesfingolipídeos/metabolismo
10.
Protein Expr Purif ; 7(2): 173-82, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8812856

RESUMO

We have expressed human monocyte chemoattractant protein-1 (hMCP-1) in preerythroid mouse erythroleukemia (MEL) C88 cells using the locus control region/MEL expression system and studied the biological activity of the purified protein in a range of in vitro experimental systems. The recombinant hMCP-1 is expressed at high levels (approximately 10 mg/liter) in this system and is modified in a manner which is very similar to native hMCP-1. We have developed a simple high-yielding two-step purification route employing dye ligand and ion exchange chromatographies which enables us to separate glycosylated and unglycosylated hMCP-1. The purified glycosylated and unglycosylated forms of hMCP-1 have equivalent biological activities in all of the assay systems tested.


Assuntos
Quimiocina CCL2/isolamento & purificação , Animais , Sequência de Bases , Northern Blotting , Cálcio/metabolismo , Quimiocina CCL2/genética , Quimiotaxia/genética , Clonagem Molecular , Primers do DNA/química , Regulação da Expressão Gênica/genética , Vetores Genéticos/genética , Glicosilação , Humanos , Leucemia Eritroblástica Aguda/metabolismo , Espectrometria de Massas , Camundongos , Dados de Sequência Molecular , Monócitos/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Transfecção/genética , Células Tumorais Cultivadas
11.
J Mol Endocrinol ; 14(2): 179-89, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7619207

RESUMO

The human breast carcinoma cell line T47D is known to express high-affinity calcitonin receptors (CTRs). PCR amplification of the CTR cDNA from T47D mRNA resulted in the identification of two different cDNAs that encode distinct receptor isoforms, h alpha CTR and h beta CTR. The two cDNAs are identical except that the h alpha CTR cDNA contains a 48 bp insert sequence that encodes a 16 amino acid domain in the first cytosolic loop of the receptor. Stable transfection of each receptor cDNA into murine erythroleukaemia (MEL) cells resulted in the expression of receptors with high affinity for radiolabelled salmon calcitonin (h alpha CTR Kd 0.09 nM, h beta CTR Kd 0.12 nM). Ligand competition binding studies did not reveal any significant pharmacological difference between the receptor isoforms. In transfected MEL cells and COS-1 cells the h beta CTR isoform was expressed at tenfold higher levels than the h alpha CTR. A reporter gene assay that monitored the coupling of CTR to adenylate cyclase by increases in beta-galactosidase activity indicated that both receptors were able to stimulate cyclic AMP production in response to ligand binding.


Assuntos
Calcitonina/metabolismo , Receptores da Calcitonina/classificação , Adenilil Ciclases/metabolismo , Sequência de Aminoácidos , Amiloide/metabolismo , Animais , Sequência de Bases , Ligação Competitiva , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Carcinoma/metabolismo , Carcinoma/patologia , AMP Cíclico/biossíntese , DNA Complementar/genética , DNA de Neoplasias/genética , Ativação Enzimática/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica , Genes Reporter , Humanos , Polipeptídeo Amiloide das Ilhotas Pancreáticas , Leucemia Eritroblástica Aguda/patologia , Camundongos , Dados de Sequência Molecular , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Conformação Proteica , Receptores da Calcitonina/efeitos dos fármacos , Receptores da Calcitonina/genética , Receptores da Calcitonina/metabolismo , Sistemas do Segundo Mensageiro/efeitos dos fármacos , Células Tumorais Cultivadas
12.
Nucleic Acids Res ; 20(5): 997-1003, 1992 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-1549512

RESUMO

We have used the human globin locus control region (LCR) to assemble an expression system capable of high-level, integration position-independent expression of heterologous genes and cDNAs in murine erythroleukaemia (MEL) cells. The cDNAs are inserted between the human beta-globin promoter and the second intron of the human beta-globin gene, and this expression cassette is then placed downstream of the LCR and transfected into MEL cells. The cDNAs are expressed at levels similar to those of the murine beta-globin in the induced MEL cells. Heterologous genomic sequences can also be expressed at similar levels when linked to to the LCR and beta-globin promoter. In addition we demonstrate that, after induction of differentiation, MEL cells are capable of secreting heterologous proteins over a prolonged time period, making this system suitable for use in continuous production systems such as hollow fibre bioreactors. The utility of the LCR/MEL cell system is demonstrated by the expression of growth hormone at high levels (greater than 100 mg/l) 7 days after induction. Since the expression levels seen do not depend upon gene amplification and are independent of the integration position of the expression cassette, it is possible to obtain clones with stable high-level expression within 3-4 weeks after transfection.


Assuntos
Clonagem Molecular/métodos , Vetores Genéticos/genética , Globinas/genética , Leucemia Eritroblástica Aguda/metabolismo , Animais , Sequência de Bases , Northern Blotting , Hormônio do Crescimento/biossíntese , Hormônio do Crescimento/genética , Humanos , Leucemia Eritroblástica Aguda/genética , Camundongos , Dados de Sequência Molecular , Mutagênese Insercional , Plasmídeos/genética , Regiões Promotoras Genéticas/genética , Células Tumorais Cultivadas
13.
Int J Cancer ; 44(3): 424-33, 1989 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-2777409

RESUMO

A procedure was devised for the identification and specific cloning of functionally rearranged variable region immunoglobulin (Ig) gene segments from genomic DNA of a murine hybridoma cell line which produces a high-affinity monoclonal antibody (MAb) directed against human carcinoembryonic antigen (CEA). The cloned, functionally-rearranged murine Ig H-chain and L-chain variable region gene segments were incorporated into plasmid vectors capable of directing the expression of a chimaeric mouse-human antibody molecule with human (gamma 4, kappa) constant region sequences. Expression plasmids were transfected into a mouse myeloma cell line by electroporation and transfectomas secreting functional chimaeric antibody selected. Chimaeric antibody generated by transfectomas was analysed and shown to compete effectively with its murine counterpart for binding to the CEA epitope, and to have an equivalent antigen-binding affinity. This anti-CEA recombinant antibody should find application in in vivo diagnosis by immunoscintigraphy of human colonic carcinoma, and possibly also in therapy of the disease, overcoming some of the difficulties associated with the repeated use of non-human immunoglobulins in human patients.


Assuntos
Anticorpos Monoclonais/genética , Antígeno Carcinoembrionário/imunologia , Clonagem Molecular , Animais , Anticorpos Monoclonais/biossíntese , Sequência de Bases , Quimera , Genes de Imunoglobulinas , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Transcrição Gênica
14.
Cell ; 52(2): 169-78, 1988 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-2830022

RESUMO

The yeast trans-activator protein GAL4, when expressed in HeLa cells, stimulates transcription from several class B (II) eukaryotic promoters containing GAL4 binding sites either as the full UASG or as synthetic 17-mers. The characteristics of this activation are indistinguishable from those of the SV40 enhancer. Transcription was similarly stimulated from either complex promoter regions containing multiple upstream elements or from a simple promoter region composed of only a TATA box. Addition of a 17-mer GAL4 binding site to the SV40 enhancer resulted in a synergistic enhancement of transcription in the presence of GAL4. Furthermore, chimeras of the human estrogen receptor DNA binding domain and either GAL4 or GCN4 activating "acidic" regions can activate a promoter region controlled by an estrogen-responsive enhancer. Together, these data indicate that the molecular mechanisms responsible for transcriptional enhancement have been conserved from yeast to man.


Assuntos
DNA Fúngico/genética , Elementos Facilitadores Genéticos , Proteínas Fúngicas/genética , Sequências Reguladoras de Ácido Nucleico , Proteínas de Saccharomyces cerevisiae , Fatores de Transcrição , Transcrição Gênica , Animais , DNA Recombinante , Proteínas de Ligação a DNA , Estrogênios/farmacologia , Globinas/genética , Células HeLa/metabolismo , Humanos , Plasmídeos , Regiões Promotoras Genéticas , Coelhos , Receptores de Estrogênio/genética , Vírus 40 dos Símios/genética , Simplexvirus/enzimologia , Simplexvirus/genética , Timidina/genética , Transfecção
15.
Bioelectromagnetics ; 1(3): 277-83, 1980.
Artigo em Inglês | MEDLINE | ID: mdl-7284026

RESUMO

In previous experiments changes were found in calcium-ion efflux from chick-brain tissue that had been exposed in vitro to 147-MHz radiation across a specific range of power densities when the field was amplitude modulated at 16 Hz. In the present study, 50-MHz radiation, similarly modulated as a sinusoid, was found to produce changes in calcium-ion efflux from chick brains exposed in vitro in a Crawford cell. Exposure conditions were optimized to broaden any power-density window and to enhance the opportunity to detect changes in the calcium-ion efflux. The results of a power-density series demonstrated two effective ranges: One spanning a range from 1.44 to 1.67 mW/cm2, and the other including 3.64 mW/cm2, which were bracketed by no-effect results at 0.72, 2.17, and 4.32 mW/cm2. peaks of positive findings are associated with near-identical rates of energy absorption: 1.4 microW/g at 147 MHz, and 1.3 microW/g at 50 MHz, which indicates that the enhanced-efflux phenomenon is more dependent on the intensity of fields in the brain than on the power density of incident radiation. In addition, the phenomenon appears to occur at multiples of some, as yet unknown, rate of radiofrequency (RF) energy absorption. Because of the extremely small increments of temperature associated with positive findings (less than 4 X 10(-4) degrees C), and the existence of more than one productive absorption rate, a solely thermal explanation appears extremely unlikely.


Assuntos
Encéfalo/efeitos da radiação , Cálcio/metabolismo , Ondas de Rádio , Animais , Encéfalo/metabolismo , Galinhas , Campos Eletromagnéticos
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