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1.
BMC Geriatr ; 23(1): 815, 2023 12 07.
Artículo en Inglés | MEDLINE | ID: mdl-38062368

RESUMEN

BACKGROUND: Dysregulated energy metabolism is one hypothesized mechanism underlying frailty. Resting energy expenditure, as reflected by resting metabolic rate (RMR), makes up the largest component of total energy expenditure. Prior work relating RMR to frailty has largely been done in cross section with mixed results. We investigated whether and how RMR related to 1-year frailty change while adjusting for body composition. METHODS: N = 116 urban, predominantly African-American older adults were recruited between 2011 and 2019. One-year frailty phenotype (0-5) was regressed on baseline RMR, frailty phenotype, demographics and body composition (DEXA) in an ordinal logistic regression model. Multimorbidity (Charlson comorbidity scale, polypharmacy) and cognitive function (Montreal Cognitive Assessment) were separately added to the model to assess for change to the RMR-frailty relationship. The model was then stratified by baseline frailty status (non-frail, pre-frail) to explore differential RMR effects across frailty. RESULTS: Higher baseline RMR was associated with worse 1-year frailty (odds ratio = 1.006 for each kcal/day, p = 0.001) independent of baseline frailty, demographics, and body composition. Lower fat-free mass (odds ratio = 0.88 per kg mass, p = 0.008) was independently associated with worse 1-year frailty scores. Neither multimorbidity nor cognitive function altered these relationships. The associations between worse 1-year frailty and higher baseline RMR (odds ratio = 1.009, p < 0.001) and lower baseline fat-free mass (odds ratio = 0.81, p = 0.006) were strongest among those who were pre-frail at baseline. DISCUSSION: We are among the first to relate RMR to 1-year change in frailty scores. Those with higher baseline RMR and lower fat-free mass had worse 1-year frailty scores, but these relationships were strongest among adults who were pre-frail at baseline. These relationships were not explained by chronic disease or impaired cognition. These results provide new evidence suggesting higher resting energy expenditure is associated with accelerate frailty decline.


Asunto(s)
Metabolismo Basal , Fragilidad , Humanos , Anciano , Fragilidad/diagnóstico , Fragilidad/epidemiología , Metabolismo Energético , Composición Corporal , Enfermedad Crónica
2.
Pol J Vet Sci ; 17(4): 725-7, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25638989

RESUMEN

The objective of this study was to determine the response of hemostatic dressings. Coagulation and fibrinolytic systems, red blood cell parameters, platelet and leukocyte counts were evaluated after the application of hemostatic dressings: QuikClot, Chitoauze and Celox gauze. The experiment was performed on ten pigs.


Asunto(s)
Vendajes/veterinaria , Hemorragia/terapia , Técnicas Hemostáticas/instrumentación , Hemostáticos , Porcinos , Heridas y Lesiones/terapia , Animales , Pruebas de Coagulación Sanguínea , Femenino
3.
J Cell Biol ; 50(3): 746-61, 1971 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-4398631

RESUMEN

Actinomycin D (AMD) at concentrations that inhibit cellular RNA synthesis by 85% or more causes an acute phase of lethal cell degeneration in HeLa cultures beginning as early as 3 hr after drug exposure, resulting in the nearly complete loss of viable cells by 12 hr. The loss of cells during this acute phase of lethality is closely dose dependent. Vero, WI38, or L cells are not susceptible to this early acute cyto-intoxication by AMD, and may begin to die only after 1-2 days. Differential susceptibility to acute cyto-intoxication by AMD, or other inhibitors of RNA synthesis (daunomycin or nogalamycin), among different types of cultured cells is analogous to that observed in vivo in certain tissues and tumors, and cannot be accounted for by differences in the effect of AMD on RNA, DNA, or protein syntheses, or by the over-all loss of preformed RNA. Actinomycin D in a dose that inhibits RNA synthesis causes an equivalent loss of the prelabeled RNA in all the cell types studied. Inhibition of protein synthesis with streptovitacin A or of DNA synthesis with hydroxyurea does not cause acute lethal injury in HeLa cells as does inhibition of RNA synthesis. Furthermore, since Vero or L cells divide at about the same rate as HeLa cells, no correlation can be drawn between the rate of cell proliferation and susceptibility to the cytotoxicity of AMD. Susceptibile cells are most vulnerable to intoxication by AMD in the G(1)-S interphase or early S phase. Inhibition of protein synthesis (which protects cells against damage by other agents affecting DNA) does not protect against AMD-induced injury. Although HeLa cells bind more AMD at a given dose than Vero or L cells, the latter cell types, given higher doses, can be made to bind proportionally more AMD without succumbing to acute cyto-intoxication. It is suggested that the differential susceptibility of these cell types to acute poisoning by AMD may reflect differences among various cells in the function or stability of certain RNA species not directly involved in translation whose presence is vital to cells. In HeLa cells, these critical species of RNA are presumed to have a short half-life.


Asunto(s)
Dactinomicina/farmacología , Animales , Isótopos de Carbono , División Celular/efectos de los fármacos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Células Cultivadas/efectos de los fármacos , Técnicas de Cultivo , ADN/antagonistas & inhibidores , ADN/biosíntesis , ADN de Neoplasias/antagonistas & inhibidores , ADN de Neoplasias/biosíntesis , Dactinomicina/metabolismo , Semivida , Haplorrinos , Células HeLa/metabolismo , Humanos , Hidroxiurea/farmacología , Riñón , Células L , Pulmón , Métodos , Ratones , Biosíntesis de Proteínas , Proteínas/antagonistas & inhibidores , ARN/antagonistas & inhibidores , ARN/biosíntesis , ARN Neoplásico/antagonistas & inhibidores , ARN Neoplásico/biosíntesis , Estreptovaricina/farmacología , Factores de Tiempo , Uridina/metabolismo
4.
J Cell Biol ; 55(2): 299-309, 1972 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-4627744

RESUMEN

After pulse exposure to concentrations of actinomycin D (AMD) sufficient to abolish transcription, Vero cells recover RNA synthesis much more rapidly than most other cell types. This is only in part attributable to the remarkable capacity of Vero very promptly to excrete bound AMD, elimination of which, although necessary, is not a sufficient condition for resurgence of RNA synthesis. After elimination of higher concentrations of AMD from Vero, although over-all RNA synthesis resumes a normal rate within 24 hr, protein synthesis lags, and a long period of division-delay ensues. Division-delay lasting 2-3 days results from exposure of Vero to doses of AMD greater than those that suppress RNA synthesis by greater than 90% (e.g. 1 microg/ml for 2 hr) but not by lower doses, which permit almost immediate reentry into the cell cycle. In contrast, although L cells recover over-all RNA synthesis very slowly after pulse treatment with AMD, resumption of protein synthesis or cell division is not comparably delayed thereafter. These and other data suggest that the early restoration of RNA synthesis in Vero after relief of inhibition by AMD is qualitatively imperfect. The results reported herein are explainable by the hypothesis that the synthesis of those species of RNA which are involved, directly or indirectly, in reactivating the transcription of genes controlling progression in the cell cycle is relatively resistant to suppression by AMD. Decay of such RNA templates and their products, which differs in different cell types during inhibition by AMD, determines the duration of division-delay.


Asunto(s)
Dactinomicina/farmacología , Biosíntesis de Proteínas , ARN/biosíntesis , Transcripción Genética/efectos de los fármacos , Aminoácidos/metabolismo , Animales , Sitios de Unión , Isótopos de Carbono , División Celular/efectos de los fármacos , Línea Celular , Relación Dosis-Respuesta a Droga , Haplorrinos , Células HeLa/efectos de los fármacos , Riñón , Células L/efectos de los fármacos , Métodos , Mitosis/efectos de los fármacos , Moldes Genéticos , Factores de Tiempo , Uridina/metabolismo
5.
J Cell Biol ; 86(3): 844-8, 1980 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-6157696

RESUMEN

A kinetic analysis of the appearance of [3H]uridine label in RNA sequences that neighbor poly(A), as well as the incorporation of [3H]adenosine label into both the RNA chain and the poly(A) of poly(A)-containing molecules, shows that poly(A) is added within a minute or so after RNA chain synthesis in Chinese hamster ovary cells and HeLa cells. Previous conclusions by several groups (5-7) that poly(A) might be added as long as 20-30 min after RNA synthesis appear to be in error, and the present conclusion seems much more in line with several different types of recent studies with specific mRNAs that suggest prompt poly(A) addition (13-16).


Asunto(s)
Núcleo Celular/metabolismo , Precursores de Ácido Nucleico/metabolismo , Poli A/metabolismo , ARN Mensajero/biosíntesis , Animales , Línea Celular , Cricetinae , Citoplasma/metabolismo , Dactinomicina/farmacología , Humanos , Cinética , ARN Nuclear Heterogéneo/metabolismo
6.
Eur J Gynaecol Oncol ; 30(4): 422-5, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19761136

RESUMEN

OBJECTIVE: The goal of the study was to analyze results of 171 second-look laparotomy and compare survival of patients with advanced ovarian cancer depending on SLL results. RESULTS: We obtained the following results: complete pathologic response (CPR)--56.2% (96 patients), microscopic disease (R(micro))--12.8% (22 patients), macroscopic disease (R(marco))--31% (53 patients). In patients with negative SLL results disease recurrence was diagnosed in 38.5%. We compared survival in separate groups of patients depending on SLL results: no difference between the CPR group and R(micro) group. Significantly longer survival of patients in the R(micro) group was found compared to patients with recurrence after negative SLL. There were no differences between the group with recurrence after negative SLL and the R(macro) group. CONCLUSIONS: An important observation is that the survival rate in patients with recurrence after negative SLL was significantly lower compared to patients with microscopic disease. The probable explanation for favorable prognosis in the group with microscopic disease was early administration of chemotherapy after SLL.


Asunto(s)
Laparotomía , Neoplasias Ováricas/cirugía , Segunda Cirugía , Adulto , Anciano , Supervivencia sin Enfermedad , Femenino , Humanos , Persona de Mediana Edad , Recurrencia Local de Neoplasia/diagnóstico , Neoplasias Ováricas/diagnóstico , Neoplasias Ováricas/patología , Pronóstico , Análisis de Supervivencia , Adulto Joven
7.
Eur J Gynaecol Oncol ; 28(2): 128-30, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17479675

RESUMEN

Persistent minimal residual disease diagnosed after the first line of chemotherapy during second-look surgery can be an indication for intraperitoneal chemotherapy. Another treatment option is intraperitoneal hyperthermic perfusion chemotherapy (IHPC) where the drug is administrated into the peritoneal cavity with the use of extracorporeal closed circuit perfusate circulation at a temperature of 41-42 degrees C. We have started to perform, as a second-line treatment, a combination of one IHPC procedure and four cycles of standard intraperitoneal chemotherapy. In a patient who had previously undergone three different chemotherapy regimens, stabilization of the disease was achieved. In our opinion combining the IHPC procedure with intraperitoneal chemotherapy can be valuable in patients with small volume residual tumor.


Asunto(s)
Antineoplásicos/administración & dosificación , Quimioterapia del Cáncer por Perfusión Regional/métodos , Hipertermia Inducida , Neoplasias Ováricas/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Cisplatino/administración & dosificación , Terapia Combinada , Ciclofosfamida/administración & dosificación , Supervivencia sin Enfermedad , Femenino , Humanos , Infusiones Parenterales/métodos , Estadificación de Neoplasias , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/cirugía , Índice de Severidad de la Enfermedad , Resultado del Tratamiento
8.
Curr Top Microbiol Immunol ; 287: 31-55, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15609508

RESUMEN

At the VIth International Symposium on Corona and Related Viruses held in Quebec, Canada in 1994 we presented a new model for coronavirus transcription to explain how subgenome-length minus strands, which are used as templates for the synthesis of subgenomic mRNAs, might arise by a process involving discontinuous RNA synthesis. The old model explaining subgenomic mRNA synthesis, which was called leader-primed transcription, was based on erroneous evidence that only genome-length negative strands were present in replicative intermediates. To explain the discovery of subgenome-length minus strands, a related model, called the replicon model, was proposed: The subgenomic mRNAs would be produced initially by leader-primed transcription and then replicated into minus-strand templates that would in turn be transcribed into subgenomic mRNAs. We review the experimental evidence that led us to formulate a third model proposing that the discontinuous event in coronavirus RNA synthesis occurs during minus strand synthesis. With our model the genome is copied both continuously to produce minus-strand templates for genome RNA synthesis and discontinuously to produce minus-strand templates for subgenomic mRNA synthesis, and the subgenomic mRNAs do not function as templates for minus strand synthesis, only the genome does.


Asunto(s)
Genoma Viral , Virus de la Hepatitis Murina/genética , Transcripción Genética , Animales , Ratones , Sistemas de Lectura Abierta/genética
9.
Eur J Gynaecol Oncol ; 26(4): 418-22, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16122192

RESUMEN

Pelvic exenteration offers the last chance for some women with gynecological and rectal malignancy. A series of 23 patients who underwent pelvic exenteration for local advanced gynecological and rectal malignancies between 1996 and 2004 were retrospectively reviewed. The exenteration was performed because of vulvar cancer in 14 patients and other pelvic malignancies in nine cases: rectal cancer in four cases, in three cases cervical cancer, in one case ovarian cancer and in one case uterine sarcoma. Nine patients developed major complications of the operative field involving the urinary tract or the wound. Early complications included massive bleeding from the sacral plexus in two cases (one patient died during surgery), acute respiratory distress syndrome (ARDS) in one case and thrombophlebitis in one case. Urinary incontinence was observed in two women as a late complication. Only one patient had a complication connected with the gastrointestinal tract. Twenty-two patients were followed-up. In the group of patients with vulvar cancer five women died after 4-29 months because of recurrence of disease. The nine surviving patients are still being followed-up and are without disease; survival time ranges from 6-74 months. In the group of patients with other malignancies four women died.


Asunto(s)
Neoplasias de los Genitales Femeninos/cirugía , Exenteración Pélvica/mortalidad , Neoplasias Pélvicas/cirugía , Complicaciones Posoperatorias , Neoplasias del Recto/cirugía , Anciano , Femenino , Neoplasias de los Genitales Femeninos/mortalidad , Humanos , Persona de Mediana Edad , Neoplasias Pélvicas/mortalidad , Neoplasias del Recto/mortalidad , Análisis de Supervivencia , Resultado del Tratamiento
10.
Chirurg ; 86(12): 1138-44, 2015 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-26347011

RESUMEN

BACKGROUND: In a prospective multicenter observational study (OCUM) neoadjuvant chemoradiotherapy (nRCT) was selectively administered depending on the risk of local recurrence and based on the distance between tumor and mesorectal fascia in pretherapeutic high-resolution magnetic resonance imaging (MRI). OBJECTIVE: Frequency and quality of abdominoperineal excision (APE) and sphincter preserving operations. PATIENTS AND METHODS: Of 642 patients treated in 13 hospitals 389 received surgery alone and 253 nRCT followed by surgery. By univariate and multivariate analysis risk factors for APE were determined. Quality parameters were the quality grade of mesorectal excision, the pathohistological involvement of the circumferential resection margin and intraoperative local dissemination of tumor cells. RESULTS AND DISCUSSION: In 12.8 % of the patients APE was performed. Independent risk factors for APE were tumor location in the lower third of the rectum and the individual hospitals, where APE varied between 0 and 32 %. This variation was chiefly caused by the different case mix. Hospitals with a high APE rate (> 30 %) treated significantly more patients with very low lying carcinomas (< 3 cm above the anal verge) and more advanced tumors. The median height of the tumor in cases of APE was nearly equal in all participating hospitals. Independent on the number of cases the quality of rectal surgery was high. Within the patient groups of primary surgery and nRCT the oncological quality parameter did not significantly differ between sphincter preservation and APE. As far as sphincter preservation is concerned the results justify a selective application of nRCT in patients with rectal carcinoma. The long-term results still have to be awaited.


Asunto(s)
Canal Anal/cirugía , Quimioradioterapia Adyuvante , Preservación de Órganos , Neoplasias del Recto/patología , Neoplasias del Recto/terapia , Adulto , Anciano , Anciano de 80 o más Años , Canal Anal/patología , Femenino , Estudios de Seguimiento , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Estudios Prospectivos , Factores de Riesgo
11.
Arch Virol Suppl ; 9: 393-405, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-8032270

RESUMEN

The genome of alphaviruses is translated into polyproteins that are processed into a viral replicase that produces both negative and positive strands. In infected cells, negative strand synthesis is short-lived and occurs only early, whereas positive strand synthesis is stable and occurs both early and late. Analysis of temperature sensitive mutants indicated: nsP1 functioned in the initiation of transcription; nsP3 acted to form initial transcription complexes; and nsP2 and nsP4 first recognized positive strands as templates and then made negative strands the preferred templates. While nsP4 and nsP1 individually rescued early defects in transcription, nsP2 and nsP3 acted initially in cis. We interpret our results to suggest nsP1234 was cleaved to nsP4, nsP1 and nsP23, bound a positive strand and synthesized a negative strand. Cleavage of P23 or other modifications to nsP2 and nsP4 convert the initial transcription complex to a stable complex that synthesizes positive strands. Negative strand synthesis is unstable because of the failure to form initial transcription complexes after host factors that are part of the replicase are depleted or the half-life of polyprotein precursors like P23 is shortened.


Asunto(s)
Alphavirus/crecimiento & desarrollo , Precursores de Proteínas/metabolismo , Procesamiento Proteico-Postraduccional , ARN Viral/biosíntesis , Proteínas no Estructurales Virales/metabolismo , Alphavirus/metabolismo , Análisis Mutacional de ADN , Prueba de Complementación Genética , Modelos Genéticos , Transcripción Genética
12.
Arch Dermatol ; 111(10): 1343-4, 1975 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-1190802

RESUMEN

A man acquired cutaneous leishmaniasis in Afghanistan. The disease involved two sites and remained active for seven months. Treatment with metronidazole was followed by resolution of the skin lesions in one month.


Asunto(s)
Leishmaniasis/tratamiento farmacológico , Metronidazol/uso terapéutico , Adulto , Humanos , Masculino , Metronidazol/administración & dosificación
13.
Adv Exp Med Biol ; 380: 499-506, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-8830530

RESUMEN

We have developed a new model for coronavirus transcription, which we call discontinuous extension, to explain how subgenome-length negatives stands are derived directly from the genome. The current model called leader-primed transcription, which states that subgenomic mRNA is transcribed directly from genome-length negative-strands, cannot explain many of the recent experimental findings. For instance, subgenomic mRNAs are transcribed directly via transcription intermediates that contain subgenome-length negative-strand templates; however subgenomic mRNA does not appear to be copied directly into negative strands. In our model the subgenome-length negative strands would be derived using the genome as a template. After the polymerase had copied the 3'-end of the genome, it would detach at any one of the several intergenic sequences and reattach to the sequence immediately downstream of the leader sequence at the 5'-end of genome RNA. Base pairing between the 3'-end of the nascent subgenome-length negative strands, which would be complementary to the intergenic sequence at the end of the leader sequence at the 5'-end of genome, would serve to align the nascent negative strand to the genome and permit the completion of synthesis, i.e., discontinuous extension of the 3'-end of the negative strand. Thus, subgenome-length negative strands would arise by discontinuous synthesis, but of negative strands, not of positive strands as proposed originally by the leader-primed transcription model.


Asunto(s)
Coronavirus/genética , Coronavirus/fisiología , Genoma Viral , ARN Mensajero/biosíntesis , ARN Viral/biosíntesis , Transcripción Genética , Replicación Viral , Animales , Secuencia de Bases , Cartilla de ADN , Ratones , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , ARN Mensajero/aislamiento & purificación , ARN Viral/aislamiento & purificación
14.
Adv Exp Med Biol ; 440: 221-6, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9782284

RESUMEN

Mutants of the A59 strain of mouse hepatitis virus (MHV) were studied to determine the effects of temperature shift on negative and positive strand RNA synthesis. Mutant LA 9 was originally reported to have a selective temperature sensitive defect in negative strand synthesis. We found that this mutant continued to synthesize negative strands for at least one hour after temperature shift. LA 6 was found to possess a temperature sensitive defect in negative strand synthesis. Following temperature shift, negative strand synthesis rapidly declined. The effect of temperature shift on negative strand synthesis by LA 6 was similar to the effect of cycloheximide treatment of the parental A59 virus. Temperature shift of Alb 16 infected cells did not stop negative strand synthesis but did prevent a corresponding rise in the rate of positive strand synthesis. Therefore, we suggest that Alb 16 is a conversion mutant because it cannot convert newly synthesized negative strands into templates for positive strand synthesis at the nonpermissive temperature.


Asunto(s)
Virus de la Hepatitis Murina/genética , ARN Viral/biosíntesis , Animales , Ratones , Mutación , Temperatura
15.
Adv Exp Med Biol ; 440: 215-9, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9782283

RESUMEN

Coronaviruses contain an unusually long (27-32,000 ribonucleotide) positive sense RNA genome that is polyadenylated at the 3' end and capped at the 5' end. In addition to the genome, infected cells contain subgenomic mRNAs that form a 3' co-terminal nested set with the genome. In addition to their common 3' ends, the genome and the subgenomic mRNAs contain an identical 5' leader sequence. The transcription mechanism that coronaviruses use to produce subgenomic mRNA is not known and has been the subject of speculation since sequencing of the subgenomic mRNAs showed they must arise by discontinuous transcription. The current model called leader-primed transcription has subgenomic mRNAs transcribed directly from genome-length negative strands. It was based on the failure to find in coronavirus infected cells subgenome-length negative strands or replication intermediates containing subgenome-length negative strands. Clearly, these structures exist in infected cells and are transcriptionally active. We proposed a new model for coronavirus transcription which we called 3' discontinuous extension of negative strands. This model predicts that subgenome-length negative strands would be derived directly by transcription using the genome RNA as a template. The subgenome-length templates would contain the common 5' leader sequence and serve as templates for the production of subgenomic mRNAs. Our findings include showing that: 1. Replication intermediates (RIs) containing subgenome-length RNA exist in infected cells and are separable from RIs with genome-length templates. The RFs with subgenome-length templates are not derived by RNase treatment of RIs with genome-length templates. 2. The subgenome-length negative strands are formed early in infection when RIs are accumulating and the rate of viral RNA synthesis is increasing exponentially. 3. Subgenome-length negative strands contain at their 3' ends a complementary copy of the 72 nucleotide leader RNA that is found in the genome only at their 5' end. 4. RIs with subgenomic templates serve immediately as templates for transcription of subgenomic mRNAs. Because subgenomic mRNAs are not replicated, i.e., copied into negative strands that in turn are used as templates for subgenomic mRNA synthesis, we propose that the subgenome-length negative strands must arise directly by transcription of the genome and acquire their common 3' anti-leader sequence after polymerase jumping from the intergenic regions to the leader sequence at the 5' end of the genome. This would make negative strand synthesis discontinuous and subgenomic mRNA synthesis continuous, which is the opposite of what was proposed in the leader primed model.


Asunto(s)
Coronavirus/genética , Modelos Genéticos , Transcripción Genética , Animales , ARN Viral/biosíntesis
16.
Adv Exp Med Biol ; 440: 735-41, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9782352

RESUMEN

Murine coronavirus MHV-A59 normally infects only murine cells in vitro and causes transmissible infection only in mice. In the 17 C1 1 line of murine cells, the receptor for MHV-A59 is MHVR, a biliary glycoprotein in the carcinoembryonic antigen (CEA) family of glycoproteins. We found that virus released from the 600th passage of 17 C1 1 cells persistently infected with MHV-A59 (MHV/pi600) replicated in hamster (BHK-21) cells. The virus was passaged and plaque-purified in BHK-21 cells, yielding the MHV/BHK strain. Because murine cells persistently infected with MHV-A59 express a markedly reduced level of MHVR (Sawicki, et al., 1995), we tested whether virus with altered receptor interactions was selected in the persistently infected culture. Infection of 17 C1 1 cells by MHV-A59 can be blocked by treating the cells with anti-MHVR MAb-CC1, while infection by MHV/BHK was only partially blocked by MAb-CC1. MHV/BHK virus was also more resistant than wild-type MHV-A59 to neutralization by purified, recombinant, soluble MHVR glycoprotein (sMHVR). Cells in the persistently infected culture may also express reduced levels of and have altered interactions with some of the Bgp-related glycoproteins that can serve as alternative receptors for MHV-A59. Unlike the parental MHV-A59 which only infects murine cells, MHV/BHK virus was able to infect cell lines derived from mice, hamsters, rats, cats, cows, monkeys and humans. However, MHV/BHK was not able to infect all mammalian species, because a pig (ST) cell line and a dog cell line (MDCK I) were not susceptible to infection. MHV/pi600 and MHV/BHK replicated in murine cells more slowly than MHV-A59 and formed smaller plaques. Thus, in the persistently infected murine cells which expressed a markedly reduced level of MHVR, virus variants were selected that have altered interactions with MHVR and an extended host range. In vivo, in mice infected with coronavirus, virus variants with altered receptor recognition and extended host range might be selected in tissues that have low levels of receptors. Depending upon the tissue in which such a virus variant was selected, it might be shed from the infected animal or eaten by a predator, thus presenting a possible means for initiating the transition of a variant virus into a new host as a model for an emerging virus disease.


Asunto(s)
Virus de la Hepatitis Murina/fisiología , Latencia del Virus , Animales , Gatos , Línea Celular , Cricetinae , Perros , Variación Genética , Ratones , Virus de la Hepatitis Murina/patogenicidad , Ratas , Selección Genética
17.
Adolescence ; 23(89): 83-8, 1988.
Artículo en Inglés | MEDLINE | ID: mdl-3381690

RESUMEN

Crisis intervention techniques in a community-based setting, including factors of immediacy of response, location, prior identification and flexibility of service, are examined. Using a community-based program which has received and dealt with 231 crisis situations over a 2-year period as a model, this study shows crisis intervention techniques to be viable and valuable in the identification of problems in the family and individual. Families which request service due to a crisis must be dealt with differently from those who seek service through traditional channels. Preventive intervention is employed to reduce the onset of more serious personality disturbance and family decomposition. Using Caplan's phases of crisis as a guide, most families dealt with in the model program showed signs of reduced conflict and a greater willingness to seek more traditional types of services.


Asunto(s)
Intervención en la Crisis (Psiquiatría) , Atención a la Salud , Objetivos , Humanos , Aceptación de la Atención de Salud , Factores de Tiempo
18.
Arq. bras. med. vet. zootec. (Online) ; 70(2): 535-544, mar.-abr. 2018. tab, graf, ilus
Artículo en Portugués | LILACS, VETINDEX | ID: biblio-910700

RESUMEN

A produção de biomassa de aveia voltada à elaboração de silagem de qualidade é dependente de elementos climáticos e nitrogênio sem ocorrência de acamamento. O objetivo do presente estudo é a definição da dose ideal do regulador de crescimento que possibilite, no máximo, 5% de acamamento de plantas de aveia, bem como a identificação das variáveis potenciais para composição do modelo de regressão linear múltipla com simulação da produtividade de biomassa à elaboração de silagem nas condições de uso do regulador, em reduzida, alta e muito alta fertilização com nitrogênio. O estudo foi conduzido em 2013, 2014 e 2015, em delineamento de blocos ao acaso, com quatro repetições em esquema fatorial 4x3, para doses de regulador (0, 200, 400 e 600mL ha-1) e doses de nitrogênio (30, 90 e 150kg ha-1), respectivamente. A dose de 495mL ha-1 de regulador se mostra eficiente na redução do acamamento de plantas de aveia em condição de reduzida, alta e muito alta fertilização com nitrogênio. A soma térmica, a precipitação, a radiação, a dose de regulador e o nitrogênio qualificam a composição do modelo de regressão linear múltipla, tornando eficiente a simulação da produtividade de biomassa da aveia para silagem ao longo do ciclo.(AU)


The production of oat biomass focused on the development of quality silage is dependent on climatic elements and nitrogen without lodging occurrence. The objective of the study is to define the optimal dose of growth regulator that allows a maximum of 5% oat plant lodging and identify potential variables for composition of multiple linear regression model with productivity simulation of biomass to the preparation of silage in the conditions of low, high and very high fertilization with nitrogen. The study was conducted in 2013, 2014, and 2015 in the randomized block design with four replications in a factorial 4x3, for regulator doses (0, 200, 400 and 600ml ha-1) and nitrogen doses (30, 90 and 150kg ha-1), respectively. The dose of 495mL ha-1 regulator is efficient in reducing the oat plant lodging in condition reduced, high, and very high fertilization with nitrogen. Thermal time, precipitation, radiation, regulator dose and nitrogen dose qualify the composition of the multiple linear regression model, making efficient the biomass oat productivity simulation for silage over the cycle.(AU)


Asunto(s)
Avena/química , Avena/crecimiento & desarrollo , Biomasa , Modelos Lineales , Nitrógeno , Ensilaje
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