RESUMO
Rats do not seek water when cellularly dehydrated until they are about 4 weeks of age. This lack of appetitive 'seeking' behavior in young rats differs from their precocious ingestive responses such as an increased intake of solutions infused into their mouths when they are dehydrated as young as 2 days of age. Using video analysis of appetitive behavior in a structured environment, we document this early absence of appetitive responding and the subsequent acquisition of dehydration-elicited appetitive behavior. Weaning age pups were separated into four conditions: (i) experienced, dehydrated; (ii) experienced, nondehydrated; (iii) inexperienced, dehydrated; and (iv) inexperienced, nondehydrated. 'Experienced' rats received a dehydration and drinking experience prior to the test, and 'dehydrated' rats were dehydrated (by injection of a salt load) at the time of test. At the test, all water and food was removed from the test cages, eliminating the confounding of appetitive and consummatory measures. Despite the fact that pups in all conditions had experience with water and had previously drunk, only the 'experienced' pups differentially sought water when dehydrated. Parallel experiments with food deprivation produced similar results. Pups did not exhibit food-seeking behavior when food-deprived unless they had previous experience with food deprivation and eating. The appetitive 'seeking' behavior for feeding also appears to be learned. Directed appetitive behavior in general may thus be acquired.
Assuntos
Comportamento Apetitivo/fisiologia , Desidratação/psicologia , Privação de Alimentos/fisiologia , Aprendizagem/fisiologia , Animais , Comportamento de Ingestão de Líquido/fisiologia , Comportamento Alimentar/fisiologia , Ratos , Ratos Sprague-DawleyRESUMO
The murine 3T3-L1 preadipocyte cell line is well characterized for its capacity to undergo differentiation into adipocytes under appropriate hormonal stimulation. p107, a member of the retinoblastoma tumor suppressor gene family has been shown to be dramatically upregulated during the early requisite clonal expansion phase of 3T3-L1 adipogenesis; however, a functional consequence has yet to be described. A phosphorothioate antisense RNA approach was utilized to determine if inhibition of p107 expression would block or perturb adipocyte differentiation. A series of three phosphorothioate oligonucleotides in antisense orientation was generated, designated AS1, AS2, and AS3 along with a sense control oligonucleotide complementary to AS1 and added to postconfluent cells at a concentration of 20 and 50 microM throughout hormonally stimulated differentiation. Treatment of cells with either concentration of the sense, AS1, AS2, or 20 microM AS3 oligonucleotides had little effect on either Oil Red O lipid accumulation or induction of p107 protein levels. In contrast, treatment with 50 microM AS3 inhibited the increase in p107 protein levels and led to a complete block in differentiation as detected by Oil Red O lipid accumulation and inhibition of adipocyte-specific mRNA expression. In addition, treatment with AS3 led to a significant inhibition of cellular proliferation associated with clonal expansion. Combined, these results provide strong evidence supporting a functional role for p107 in 3T3-L1 adipocyte differentiation.
Assuntos
Adipócitos/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Proteínas Nucleares/antagonistas & inibidores , Oligonucleotídeos Antissenso/farmacologia , Células 3T3 , Adipócitos/citologia , Animais , Camundongos , Proteínas Nucleares/genética , Proteína p107 Retinoblastoma-LikeRESUMO
Leptin, the recently cloned product of the obese (ob) gene, is a 16 kDa-protein that acts as a circulating satiety factor. It also serves to regulate energy expenditure and may act as a counter regulatory hormone to insulin. Initially thought to be exclusively produced by mature adipocytes, its mRNA has now been identified in significant levels in the placenta as well as the fetus raising speculation regarding its importance as a growth factor. Given studies demonstrating that exclusively breast-fed infants are leaner due to decreased energy intakes than formula-fed infants, we hypothesized that the presence of leptin in human milk could participate in mediating the earlier satiety of those infants fed human milk. We undertook this initial study to qualitatively examine the presence of leptin in human milk utilizing an immunoblot approach. Random milk samples during the first 2 weeks of lactation were available for study from 4 mothers delivering at term. Milk samples were centrifuged, the aqueous layer removed, and the protein content quantitated. One-hundred micrograms of total protein were separated by sodium dodecyl sulfate-polyacrylamide-gel electrophoresis (SDS-PAGE), transferred to nitrocellulose, and immunoblotted with an antileptin antibody. As controls, recombinant human leptin alone and a sample of milk containing added leptin were similarly electrophoresed and immunoblotted. Labeled proteins were visualized by chemiluminescence. Significant amounts of leptin protein were identified in all milk samples examined. No difference in protein detection was identified in fresh milk vs. frozen milk, and little difference was apparent in foremilk samples vs. hindmilk samples. These preliminary data reveal the presence of leptin in term human milk and suggest that further studies to document bioactivity of milk-derived leptin are warranted.
Assuntos
Leptina/análise , Leite Humano/química , Feminino , Congelamento , Humanos , Manejo de EspécimesRESUMO
OBJECTIVE: The aims of this study were to substantiate the previously reported activity of ifosfamide in patients with advanced, persistent, or recurrent carcinosarcoma (mixed mesodermal sarcoma) of the uterus, and to determine whether the addition of cisplatin results in an improved response or survival. Secondarily, we sought to determine the toxicity of ifosfamide-cisplatin in this patient population. METHODS: Patients were randomized to receive ifosfamide (1.5 g/m(2)/day) times 5 days every 3 weeks for eight courses with mesna uroprotection, with or without cisplatin (20 mg/m(2)/day) times 5 days. No patient had received previous chemotherapy. RESULTS: Of 224 patients entered on this study, 30 were ineligible for a variety of reasons, leaving 194 evaluable patients. Early in the study, the dose of the combination regimen was reduced by 20% (1 day) because of toxicity. The investigational arms were balanced for age, grade, and Gynecologic Oncology Group performance status. Percentages of adverse effects reported in 191 patients receiving chemotherapy included (ifosfamide/cisplatin-ifosfamide) grade 3 or 4 granulocytopenia (36/60), grade 3 or 4 anemia (8/17), grade 3 or 4 central nervous system toxicity (19/14), and grade 3 or 4 peripheral neuropathy (1/12). Treatment may have contributed to the deaths of 6 patients treated with full doses of ifosfamide and cisplatin for 5 days. The proportion of patients responding to ifosfamide alone versus ifosfamide-cisplatin therapy was (0.36 versus 0.54) overall, 0.47 versus 0.61 for pelvic, 0.21 versus 0.54 for lung, and 0.33 versus 0.40 for "other" metastatic sites of measurable disease. The relative odds ratio of response adjusted for measurable sites of disease was 1.82 (P = 0.03, one-tailed test; 95% lower confidence limit, 1.06). Progression-free survival (PFS) and survival data suggest that the combination offers a slight prolongation of PFS (relative risk, 0.73; 95% upper confidence limit, 0.94; P = 0.02, one-tailed test), but no significant survival benefit (relative risk, 0.80, 95% upper confidence limit, 1.03; P = 0.071, one-tailed test). CONCLUSION: The addition of cisplatin to ifosfamide appears to offer a small improvement in progression-free survival over ifosfamide alone in the management of advanced carcinosarcoma of the uterus; the added toxicity may not justify the use of this combination.
Assuntos
Antineoplásicos Alquilantes/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinossarcoma/tratamento farmacológico , Ifosfamida/uso terapêutico , Neoplasias Uterinas/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos Alquilantes/administração & dosagem , Antineoplásicos Alquilantes/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Intervalo Livre de Doença , Feminino , Humanos , Ifosfamida/administração & dosagem , Ifosfamida/efeitos adversos , Pessoa de Meia-IdadeRESUMO
Continuous infusion of ethanol-containing diets has been demonstrated to generate well-defined pulses in blood and urine ethanol concentrations that occur with a frequency of approximately 6 days. The present study aimed to determine if hepatic class I alcohol dehydrogenase was the cause of these cycles. Adult male rats were fed an ethanol-containing diet by continuous intragastric infusion. Hepatic ADH activity, class I ADH mRNA level and rate of class I ADH gene transcription fluctuated in a cyclic pattern that positively correlated with UECs, and inhibition of ADH with 4-methylpyrazole abolished the UEC pulses. These data demonstrate for the first time an ethanol-dependent regulation of rat hepatic class I ADH. The cyclic behavior of the ethanol levels correlates with changes in class I ADH expression and implies adaptability of the ethanol eliminating system to high concentrations of alcohol.
Assuntos
Álcool Desidrogenase/biossíntese , Depressores do Sistema Nervoso Central/administração & dosagem , Etanol/administração & dosagem , Fígado/enzimologia , Periodicidade , Animais , Depressores do Sistema Nervoso Central/sangue , Depressores do Sistema Nervoso Central/urina , Etanol/sangue , Etanol/urina , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Masculino , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-DawleyRESUMO
PURPOSE: On the basis of the activity of paclitaxel as a single agent in chemotherapy-naive squamous cell carcinoma of the cervix in a prior Gynecologic Oncology Group (GOG) trial, a phase II study of paclitaxel and cisplatin as first-line therapy was conducted by the GOG. PATIENTS AND METHODS: Eligibility included squamous cell cancer of the cervix not curable by surgery or radiation, measurable disease, WBC count > or = 3,000/microL, platelet count > or = 100, 000/microL, serum creatinine > or = 2 mg/100 mL, and adequate hepatic function. The starting dose was paclitaxel 135 mg/m(2) infused over 24 hours followed by cisplatin 75 mg/m(2) every 21 days. On the basis of toxicity, a dose escalation of paclitaxel to a maximum dose of 170 mg/m(2)/d was prescribed. RESULTS: Forty-seven patients were enrolled onto this study; 44 patients were assessable for toxicity and 41 for response. Forty (90.9%) had received prior radiation therapy. A median of six courses of chemotherapy was given (range, one to 10 courses). Neutropenia grade 3 (15.9%) and 4 (61.4%) was the most frequent severe adverse effect and was associated with fever in 13 patients (27.7%). Two patients (4.5%) died from neutropenic sepsis. Grade 4 thrombocytopenia occurred in 6.8% of patients. Of 41 assessable patients, five (12.2%) had complete responses and 14 (34.1%) had partial responses for an overall response rate of 46.3% (95% confidence interval, 30.7% to 62.6%). The median progression-free interval, was 5.4+ months (range, 0.3 to 22+ months) with a median survival of 10.0+ months (range, 0.9 to 22. 2 months). Response was more frequent in patients with disease in nonirradiated sites (70% v 23%, P =.008). CONCLUSION: This regimen seems highly active in advanced and recurrent squamous cell carcinoma of the cervix and is currently being evaluated by the GOG in a phase III randomized study comparing the combination of paclitaxel and cisplatin with cisplatin alone.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Escamosas/tratamento farmacológico , Neoplasias do Colo do Útero/tratamento farmacológico , Adulto , Idoso , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/radioterapia , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Feminino , Humanos , Pessoa de Meia-Idade , Neutropenia/induzido quimicamente , Paclitaxel/administração & dosagem , Paclitaxel/efeitos adversos , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/radioterapiaRESUMO
Significant advances have been made recently toward understanding the molecular events that regulate adipocyte differentiation. In vitro models of adipogenesis, such as the 3T3-L1 and F-442A preadipocyte cell lines have proven to be an invaluable resource in elucidating mechanisms of adipocyte differentiation. Subject to modulation by hormonal, dietary, and genetic influences, the differentiation program now appears to be distinctly controlled through the coordinate regulation of transcription factors that predominantly include members of the C/EBP and PPAR families. Increased understanding of these critical factors and how they are regulated will provide insights into adipose tissue development as well as treatment of obesity.
Assuntos
Adipócitos/citologia , Adipócitos/metabolismo , Células 3T3 , Adipócitos/efeitos dos fármacos , Adipócitos/fisiologia , Animais , Proteínas Estimuladoras de Ligação a CCAAT , Proteínas de Ligação ao Cálcio , Diferenciação Celular/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/farmacologia , Proteínas de Ligação a DNA/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Inibidores do Crescimento/farmacologia , Humanos , Peptídeos e Proteínas de Sinalização Intercelular , Proteínas de Membrana/farmacologia , Camundongos , Proteínas Nucleares/metabolismo , Proteínas Nucleares/farmacologia , Proteínas Nucleares/fisiologia , Obesidade/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Receptores Citoplasmáticos e Nucleares/fisiologia , Proteínas Repressoras/farmacologia , Proteína do Retinoblastoma/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1 , Fator de Transcrição AP-2 , Fatores de Transcrição/metabolismo , Fatores de Transcrição/fisiologia , Tretinoína/farmacologia , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
The potential of infant diet to influence fat cell development has largely been examined in clinical studies with conflicting results. In this study, the direct effects of two standard infant formulas, Enfamil and Similac, as well as human milk were examined using a well characterized model of adipocyte differentiation, the 3T3-L1 murine preadipocyte cell line. After exposure to a hormonal regimen of insulin, dexamethasone, and 1-methyl-3-isobutylmethylxanthine, these cells undergo a mitotic expansion phase followed by terminal differentiation. On d 4 of hormonal exposure, greater than 95% of 3T3-L1 cells exhibit the morphologic and biochemical characteristics of mature adipocytes. In this study, cells were exposed to control medium, or control medium supplemented with either 10% Enfamil, 10% Similac, 10% human milk (skim or whole), or the standard hormonal regimen. Oil Red O-detectable lipid accumulation, immunocytochemical cell proliferation assays, and activated expression of adipocyte differentiation-specific mRNAs by Northern blot analysis were used to assess the effects of treatment on adipocyte differentiation. Results from each level of assessment revealed that both Enfamil and human milk were as effective as the standard hormonal regimen at stimulating adipocyte differentiation. In contrast, results from treatment with Similac or human skim milk were indistinguishable from control unstimulated cells. This study, demonstrating that Enfamil and human milk are capable of independently inducing in vitro adipocyte differentiation, suggests that diet during infancy could influence body fat development.
Assuntos
Adipócitos/citologia , Alimentos Infantis , Leite Humano , Células 3T3 , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Células Clonais/efeitos dos fármacos , Humanos , Metabolismo dos Lipídeos , Camundongos , Mitose/efeitos dos fármacos , RNA Mensageiro/metabolismoRESUMO
The inhibitory effects of TNFalpha on adipocyte differentiation are well described, however, the mechanisms are poorly understood. Early during hormonally-induced 3T3-L1 preadipocyte differentiation there is a requisite mitotic clonal expansion phase that is associated with significant regulation in p130 and p107 protein levels, two members of the retinoblastoma protein family that regulate cell cycle events through interactions with the E2F transcription factors. This regulation occurs within the first 24 hours of differentiation (Day 1) and is characterized by a transient increase in p107 protein and mRNA levels as well as a transient decrease in p130 protein levels. Here we describe that TNFalpha disrupts the normal pattern of expression of both p130 and p107 proteins, leading to a complete block in mitotic clonal expansion. Interestingly, TNFalpha-treated cells enter S-phase as determined by 5-bromo-2'-deoxyuridine uptake experiments, but rather than completing cell cycle, they are stimulated to undergo apoptosis.
Assuntos
Adipócitos/efeitos dos fármacos , Proteínas , Proteína do Retinoblastoma/genética , Proteína do Retinoblastoma/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Células 3T3 , Adipócitos/citologia , Adipócitos/metabolismo , Animais , Apoptose/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Imuno-Histoquímica , Camundongos , Peso Molecular , Proteínas Nucleares/química , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fosfoproteínas/química , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteína do Retinoblastoma/química , Proteína p107 Retinoblastoma-Like , Proteína p130 Retinoblastoma-LikeRESUMO
BACKGROUND: We sought to assess the practice patterns of former obstetric-gynecologic residents and to solicit their opinions regarding their educational experience and its clinical relevance to primary care. METHOD: In response to a Residency Review Committee mandate regarding past residents, a questionnaire was sent to all graduates from our residency program over a 17-year period (1979 to 1995). RESULTS: Of the 90 subjects who received the survey, 86 responded. Their ages ranged from 29 years to 49 years; 79 were married and 7 were single. Of the 75 in clinical practice, 71 practiced both obstetrics and gynecology and 13 had subspecialized. Most of the respondents (77/80) practiced in the mid-South. Of all graduates, 93% routinely provided primary care. In rating 20 major resident education categories, respondents gave high grades to training in surgically related areas. Only 4% rated their experience as fair or poor in the operative categories. CONCLUSION: Our graduates indicate satisfaction with their training, and their practices include primary care.
Assuntos
Ginecologia , Internato e Residência/normas , Obstetrícia , Padrões de Prática Médica , Adulto , Humanos , Pessoa de Meia-Idade , Atenção Primária à Saúde , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Our objective was to assess the educational benefits of a formal pathology rotation during an obstetrics and gynecology residency program and to determine the utility of this information in clinical practice. METHODS: In this descriptive study, the benefits of a 2-month rotation in pathology for obstetrics and gynecology residents were analyzed. A computerized listing of surgical cases processed by each resident was sent to the obstetrics and gynecology program director. RESULTS: Our resident accessioned 5.4% of the total pathology cases processed each month. Reports from previous residents (over a 17-year period) and from program directors at the annual educational retreat indicate that such information was not relevant to our graduates in their clinical practice. CONCLUSIONS: A formal pathology rotation for obstetric residents can improve knowledge base, but the usefulness of this knowledge in clinical practice is dubious.
Assuntos
Ginecologia/educação , Internato e Residência/métodos , Obstetrícia/educação , Patologia Clínica/educação , Currículo , Humanos , Inquéritos e QuestionáriosRESUMO
The homeobox family of proteins are transcription factors are known to be important during the differentiation of a variety of mammalian tissues, however, expression of the genes encoding homeobox proteins during adipogenesis or in adipose tissue has not been described. To investigate whether members of the homeobox gene family are expressed and regulated during adipocyte differentiation, RNA was isolated from 3T3-L1 preadipocyte cells during the hormonal induced differentiation of this cell line into adipocytes. A reverse transcriptase-polymerase chain reaction strategy using degenerate oligonucleotide primers complementary to the highly conserved homeodomain resulted in the identification of 10 different homeobox genes expressed during 3T3-L1 adipogenesis. One of the clones appears to be unique and 9 of the clones represented known members of the homeobox gene family. Examination of the relative mRNA levels encoding these proteins by ribonuclease protection assay during adipocyte differentiation revealed that 3 members, Hox a4, Hox a7, and Hox d4, are regulated as a function of adipocyte development. Further examination of RNA isolated from murine retroperitoneal adipose tissue revealed that these three regulated homeobox mRNAs are expressed in vivo. Combined, these results suggest that members of the homeobox gene family may serve an important role during the differentiation of adipocytes.
Assuntos
Adipócitos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Genes Homeobox , Células 3T3 , Sequência de Aminoácidos , Animais , Sequência de Bases , Diferenciação Celular/genética , Camundongos , Dados de Sequência MolecularRESUMO
Chronic exposure to ethanol is known to cause a dramatic increase in the level of CYP 2E1 apoprotein. More recently it has been demonstrated that under certain conditions the mRNA encoding cytochrome P450 2E1(CYP 2E1) is inducible; however, the mechanisms by which these increases occur are not well understood. In the current study, DNase I footprinting assays performed on the first kilobase of the CYP 2E1 5'-flanking sequences resulted in the identification of 13 sequence-specific protected regions using rat liver nuclear extracts isolated from either control or ethanol-treated animals. No differences were observed in the DNase I footprint patterns produced by the two different nuclear extracts. In addition, analysis by electrophoretic mobility shift assays (EMSA) revealed that with one exception, there were no differences in the level of binding complexes between the two extracts. However, EMSA analysis with an oligonucleotide to one footprint site (designated Site C) revealed that in nuclear extracts isolated from ethanol-treated animals there was a 2.9-fold increase in this binding complex when compared to control nuclear extracts. This site was previously shown to contain an HNF-1alpha binding site, and here we demonstrate that bacterially expressed HNF-1alpha in footprint assays bind Site C sequences and that HNF-1alpha transactivates the CYP 2E1 promoter in co-transfection experiments with HNF-1alpha expression plasmid and plasmids containing CYP 2E1 promoter sequences coupled to the chloramphenicol acetyl transferase gene. Furthermore, in contrast to the increase observed by EMSA in Site C binding, no increase was detected in the CYP 2E1 transcriptional rate supported by nuclear extracts from ethanol-treated animals over controls using in vitro transcription assays, suggesting that the increase by ethanol in CYP 2E1 transcription is not mediated through the HNF-1alpha site.
Assuntos
Citocromo P-450 CYP2E1/genética , Proteínas de Ligação a DNA , Etanol/administração & dosagem , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Fígado/efeitos dos fármacos , Proteínas Nucleares , Animais , Sítios de Ligação , Etanol/farmacologia , Fator 1 Nuclear de Hepatócito , Fator 1-alfa Nuclear de Hepatócito , Fator 1-beta Nuclear de Hepatócito , Humanos , Fígado/enzimologia , Masculino , Regiões Promotoras Genéticas , Ratos , Ratos Sprague-Dawley , Fatores de Transcrição/metabolismo , Células Tumorais CultivadasRESUMO
BACKGROUND AND OBJECTIVE: The authors studied the efficacy and complications of intraoperative mitomycin-C in glaucoma associated with ocular inflammation. PATIENTS AND METHODS: The authors retrospectively reviewed the medical records of 24 consecutive patients (24 eyes) with glaucoma and ocular inflammation who had been treated with trabeculectomy and intraoperative mitomycin-C. Patient ages ranged from 10 to 83 years (mean 43 years). All patients were observed for at least 6 months. RESULTS: With a mean follow-up time of 14.6 months, 18 of the 24 patients (75%) retained vision and had an intraocular pressure of 21 mm Hg or lower with or without medications (range 4 to 21 mm Hg; mean 13.4 mm Hg). Fifteen of 24 patients (62%) had an intraocular pressure of 21 mm Hg or lower with no medications. Three patients required tube shunt implants. One patient had a retinal detachment and lost light perception. One patient had endophthalmitis 14 months after surgery. Seven of 24 patients lost two or more lines of Snellen acuity. CONCLUSION: Trabeculectomy with mitomycin-C can control intraocular pressure in glaucoma associated with ocular inflammation, but complications are frequent.
Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Glaucoma/terapia , Mitomicina/administração & dosagem , Trabeculectomia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Quimioterapia Adjuvante , Criança , Feminino , Seguimentos , Glaucoma/complicações , Humanos , Pressão Intraocular , Cuidados Intraoperatórios , Masculino , Pessoa de Meia-Idade , Soluções Oftálmicas , Complicações Pós-Operatórias , Estudos Retrospectivos , Resultado do Tratamento , Uveíte/complicações , Uveíte/terapiaRESUMO
During 3T3-L1 adipocyte differentiation, growth-arrested, postconfluent preadipocytes are required to reenter the cell cycle and proceed through a mitotic clonal expansion phase prior to terminal differentiation. The retinoblastoma proteins (pRB, p107, and p130) are thought to be critical in controlling cell cycle progression by binding to and regulating the activity of the E2F transcription factors. We show here that p130/p107 protein levels, p107 mRNA levels, and E2F DNA binding complexes are regulated during 3T3-L1 adipogenesis. The predominant E2F binding complex in day 0 preadipocytes was p130-E2F with no detectable free E2F or p107. On Day 1, during mitotic clonal expansion, there was a distinct switch to free E2F and p107-E2F complexes associated with increased p107 mRNA and protein along with decreased p130 protein levels. Following differentiation, the day 0 pattern is reestablished. The switch is not just a consequence of reentry into the cell cycle, in that p107 protein levels are both detectable and unchanged in dividing, serum-restricted, or serum restimulated preconfluent cells. Interestingly, hormonal stimulation of 3T3-C2 cells, a related nondifferentiating cell line, also induces a mitotic clonal expansion phase that is associated with the p130:p107 switch in a pattern very similar to 3T3-L1 cells, suggesting the block in differentiation observed in 3T3-C2 cells occurs after clonal expansion. Combined, these findings suggest that the regulatory mechanisms of the p130:p107 switch are not specific to differentiation but may play a key role in regulating the mitotic clonal expansion necessary for adipocyte differentiation in 3T3-L1 cells.
Assuntos
Adipócitos/citologia , Proteínas de Transporte , Inibidores do Crescimento/metabolismo , Proteínas Nucleares/metabolismo , Fosfoproteínas/metabolismo , Proteínas , Proteína do Retinoblastoma/metabolismo , Células 3T3 , Animais , Ciclo Celular , Proteínas de Ciclo Celular/metabolismo , Diferenciação Celular , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição E2F , Eletroforese em Gel de Poliacrilamida , Camundongos , RNA Mensageiro/metabolismo , Proteína 1 de Ligação ao Retinoblastoma , Proteína p107 Retinoblastoma-Like , Proteína p130 Retinoblastoma-Like , Fator de Transcrição DP1 , Fatores de Transcrição/metabolismoRESUMO
Piroxantrone was administered at a starting dose of 160 mg m2 given as a 1-h infusion every 3 weeks to 19 patients with histologically confirmed advanced, persistent, or recurrent squamous cell carcinoma of the cervix. All patients were required to have measurable disease and no prior chemotherapy. Eighteen women were evaluable for toxicity and response. Toxicity was modest and consisted primarily of myelosuppression with six (33%) patients experiencing grade 3 or 4 leukopenia. There were no complete (CR) or partial responses (PR) among the 18 evaluable patients. Six (33%) patients had stable disease while on treatment and 12 (67%) patients experienced progressive disease. Piroxantrone appears to have no beneficial effect in advanced or recurrent squamous cell cancer of the cervix at this dose and schedule.
Assuntos
Antraquinonas/uso terapêutico , Antineoplásicos/uso terapêutico , Carcinoma de Células Escamosas/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Pirazóis/uso terapêutico , Neoplasias do Colo do Útero/tratamento farmacológico , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-IdadeRESUMO
OBJECTIVE: The objective of the study was to determine the response rate and associated toxicity of 5-fluorouracil and high-dose leucovorin in patients with recurrent adenocarcinoma of the cervix. METHODS: Between December 1993 and October 1995, 53 patients with recurrent adenocarcinoma of the cervix were entered into a Phase II trial utilizing 200 mg/m2 of intravenous (iv) leucovorin with 370 mg/m2 of i.v. 5-fluorouracil daily for 5 days every 4 weeks for two courses, then every 5 weeks until disease progression. Eligibility criteria were a Gynecologic Oncology Group (GOG) performance status of 0-2, adequate bone marrow reserve, adequate liver function with bilirubin < or = 1.5 x normal and SGOT and alkaline phosphatase < or = 3 x normal, serum creatinine < or = 2 mg%, and signed informed consent. Standard GOG toxicity and response criteria were employed. RESULTS: Six patients were ineligible because of wrong cell type (N = 3), insufficient pathology materials (N = 2), or a second primary (N = 1); therefore 45 were evaluable for toxicity. Two patients did not have adequate response assessment; thus, 43 were evaluable for response. The median age was 50 (range, 28-79). Prior chemotherapy had been administered to 16 patients and radiotherapy to 40 patients. The median number of courses delivered was three (range, 1-22). The site of evaluable disease was pelvic in 25 patients and extra-pelvic in 18. Grade 3 neutropenia was seen in 17.8% (8/45) patients and 35.5% (16/45) developed grade 4 neutropenia. Grade 3 or 4 thrombocytopenia was seen in 1 patient each (2.1%). Grade 3 gastrointestinal toxicity with nausea, vomiting, diarrhea, dehydration, or stomatitis was of grade 3 severity in 11.1% (5/45) and grade 4 in 6.7% (3/45). There were four partial responses and two complete responses for an overall response rate of 14%. The duration of the complete responses was 17.3 and 8.8+ months. None of the patients with responses had previously received chemotherapy. CONCLUSION: The schedule of 5-fluorouracil and leucovorin exhibits moderate activity in patients with previously treated adenocarcinoma of the cervix and should be considered for a trial in chemotherapy-naive patients.
Assuntos
Adenocarcinoma/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias do Colo do Útero/tratamento farmacológico , Adulto , Idoso , Antimetabólitos Antineoplásicos/administração & dosagem , Esquema de Medicação , Feminino , Fluoruracila/administração & dosagem , Humanos , Leucovorina/administração & dosagem , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Resultado do TratamentoRESUMO
The Mississippi Breast and Cervical Cancer Control Coalition conducted a survey of health care professionals to assess current practices in the areas of breast and cervical cancer screening. A 22% response rate was obtained, with family practitioners having the highest response rate. Cost was cited as a major barrier to access to screening mammography. Some discrepancies between provider perceptions and currently accepted guidelines were identified.
Assuntos
Atitude do Pessoal de Saúde , Neoplasias da Mama/prevenção & controle , Programas de Rastreamento , Neoplasias do Colo do Útero/prevenção & controle , Fatores Etários , Neoplasias da Mama/diagnóstico por imagem , Coleta de Dados , Feminino , Humanos , Mamografia/estatística & dados numéricos , Médicos , Neoplasias do Colo do Útero/diagnóstico , Esfregaço Vaginal/estatística & dados numéricosRESUMO
The Differentiation-Specific Element Binding Protein (DSEB) was identified by binding to a specific cis-acting DNA element (DSE) responsible for the irreversible continued expression of the angiotensinogen gene after differentiation of 3T3-L1 adipoblasts to adipocytes. It was also identified as the large subunit of the Replication Factor C complex. During 3T3-L1 adipoblast differentiation, DSEB is induced early and interacts with the DSE that is essential for the sustained transcriptional activation of the angiotensinogen gene. Here we describe loss of function studies in 3T3-L1 cells performed with antisense phosphorothioate oligonucleotides that hybridize to DSEB mRNA. Treatment with 15, 25, and 50 microM antisense DSEB resulted in a dose-dependent inhibition of differentiation-specific lipid accumulation after 3 days of hormonal stimulation. Similar treatment also markedly reduced differentiation-dependent expression of mRNAs encoding angiotensinogen and the fat-specific fatty acid binding protein, aP2. Further, 50 microM antisense DSEB treatment resulted in a significant approximately 50% inhibition of the cell proliferation that occurs early in 3T3-L1 adipogenesis. Control experiments using the DSEB sense oligonucleotide had no effect on hormonal-stimulated adipocyte differentiation. Combined, these results suggest that DSEB serves an important role during the proliferative phase of 3T3-L1 adipoblast differentiation.
Assuntos
Adipócitos/efeitos dos fármacos , Proteínas de Ligação a DNA/genética , Oligonucleotídeos Antissenso/farmacologia , RNA Mensageiro/genética , Fatores de Transcrição , Células 3T3 , Adipócitos/citologia , Animais , Diferenciação Celular/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , Camundongos , Proteína de Replicação CRESUMO
BACKGROUND: Medical treatment of ectopic pregnancy with methotrexate is an increasingly common alternative to surgical management. Initial reports of methotrexate therapy described a very low incidence of complications. We report our experience with two patients who developed profound toxicity following methotrexate treatment of ectopic pregnancy. CASE: The first patient received a single dose of methotrexate (50 mg/m2 intramuscularly) for a confirmed ectopic pregnancy. The second patient received three doses of methotrexate (1 mg/kg). Both patients developed life-threatening neutropenia and febrile morbidity requiring hospitalization and supportive care. CONCLUSION: To our knowledge, this is the first description of significant morbidity secondary to bone marrow suppression following methotrexate treatment of ectopic pregnancy. Most patients with ectopic pregnancy who are treated with methotrexate can expect resolution of their symptoms and a low risk of mild complications. However, serious complications after this therapy are possible and may occur even with the single-dose regimen.