RESUMEN
Intense pulsed light systems are currently in widespread use in clinical applications. Verification of spectral content and associated pulse waveforms is, however, not featured in product support and calibration. A measurement system was developed to determine the spectral output of such sources within a series of discrete wavelength intervals. Such a system utilised a series of 11 broadband optical filters with centre wavelengths within the range 450-950 nm in circuit with silicon photodiodes as optical detectors. Signals were captured using a low cost 8-channel 16-bit universal serial bus data capture module interfaced to a laptop computer. This allowed the pulse profile of selected filter components to be separately captured and analysed. Calibration of individual filter channels was undertaken using a Bentham dmc150 spectroradiometer and reference tungsten light source. Initial measurements undertaken of the intense pulsed light output of a Lumenis One system using the system are described.
Asunto(s)
Óptica y Fotónica/instrumentación , Fototerapia/instrumentación , Análisis Espectral/instrumentación , Calibración , Diseño de Equipo , Filtración/instrumentación , Procesamiento de Señales Asistido por ComputadorRESUMEN
Seven hundred fifteen crossbred (primarily British) calves purchased in southern Oklahoma and northern Texas auction barns were received at the Willard Sparks Beef Research Center, Stillwater, OK, and used to study effects of duration (days) of vitamin E feeding during a 42-d receiving period on animal performance, health, and serum cholesterol and vitamin E concentrations. Upon arrival, calves were blocked by load (seven loads), sorted by BW (light, n = 4 pens per load; and heavy, n = 4 pens per load), and assigned randomly to one of four dietary treatments (n = 2 pens per load; 14 pens per treatment). Experimental diets were formulated to provide 2,000 IU.calf(-1).d(-1) of supplemental vitamin E (dl-alpha-tocopherol acetate) for 0 (CON), 7 (E7), 14 (E14), or 28 (E28) d. Vitamin E was delivered in a pelleted supplement that was added to the basal diet in decreasing concentrations as DMI increased (2.0 kg of DMI = 6%; 4.0 kg of DMI = 4%; and 6.0 kg of DMI = 2%). Serum samples were collected on d 0, 14, 28, and 42 for determination of cholesterol, alpha-tocopherol (d 0, 28, and 42), and antibody (IgG) concentrations. Duration of vitamin E supplementation did not affect ADG (0.98 kg/d; P = 0.56) or G:F (0.189; P = 0.87). Serum cholesterol concentrations decreased (day effect; P < 0.001) for all treatments from d 0 (average = 127 mg/100 mL) to 14 (average = 62 mg/100 mL). Serum alpha-tocopherol decreased (day effect; P < 0.001) from d 0 (5.2 microg/mL) to 28 (1.8 microg/mL); however, on d 28, a greater (P < 0.001) serum alpha-tocopherol concentration was observed for E28 (3.4 microg/mL) calves than for CON (1.1 microg/mL), E7 (1.2 microg/mL), or E14 (1.5 microg/mL) calves. Respiratory disease was diagnosed in 64.6% of calves in this study. Medical costs were less (P = 0.08) for calves fed vitamin E for 28 d (4.88 dollars/calf) than for calves fed the control diet (6.29 dollars/calf). Carcass characteristics were not affected (P = 0.19 to 0.88) by dietary treatments. Supplemental vitamin E formulated for 2,000 IU.calf(-1).d(-1) had little influence on performance and overall health status of calves under our experimental conditions; however, the increased serum concentrations of alpha-tocopherol when vitamin E was fed for 28 d suggests that any potential effects of vitamin E on health status might be time-dependent.
Asunto(s)
Alimentación Animal , Antioxidantes/uso terapéutico , Bovinos/metabolismo , Estrés Fisiológico , Vitamina E/uso terapéutico , Crianza de Animales Domésticos , Animales , Enfermedades de los Bovinos/etiología , Estado de Salud , Masculino , Enfermedades Respiratorias/etiología , Transportes , alfa-Tocoferol/sangreRESUMEN
The TRPC3 channel, an intensively studied member of the widely expressed transient receptor potential (TRP) family, is a Ca(2+)-conducting channel activated in response to phospholipase C-coupled receptors. Despite scrutiny, the receptor-induced mechanism to activate TRPC3 channels remains unclear. Evidence indicates TRPC3 channels interact directly with intracellular inositol 1,4,5-trisphosphate receptors (InsP(3)Rs) and that channel activation is mediated through coupling to InsP(3)Rs. TRPC3 channels were expressed in DT40 chicken B lymphocytes in which all three InsP(3)R genes were deleted (DT40InsP(3)R-k/o). Endogenous B-cell receptors (BCR) coupled through Syk kinase to phospholipase C-gamma (PLC-gamma) activated the expressed TRPC3 channels in both DT40w/t and DT40InsP(3)R-k/o cells. The diacylglycerol (DAG) analogue 1-oleoyl-2-acetyl-sn-glycerol (OAG) also activated TRPC3 channels independently of InsP(3)Rs. BCR-induced TRPC3 activation was blocked by the PLC enzymic inhibitor, U-73122, and also blocked by wortmannin-induced PLC substrate depletion. Neither U-73122 nor wortmannin modified either OAG-induced TRPC3 activation or store-operated channel activation in DT40 cells. Cotransfection of cells with both G protein-coupled M5 muscarinic receptors and TRPC3 channels resulted in successful M5 coupling to open TRPC3 channels mediated by PLC-beta. We conclude that TRPC3 channels are activated independently of InsP(3)Rs through DAG production resulting from receptor-mediated activation of either PLC-gamma or PLC-beta.
Asunto(s)
Canales de Calcio/genética , Canales Iónicos/biosíntesis , Receptores Citoplasmáticos y Nucleares/genética , Androstadienos/farmacología , Animales , Animales Modificados Genéticamente , Linfocitos B/metabolismo , Calcio/metabolismo , Canales de Calcio/fisiología , Línea Celular , Células Cultivadas , Pollos , ADN Complementario/metabolismo , Inhibidores Enzimáticos/farmacología , Precursores Enzimáticos/metabolismo , Estrenos/farmacología , Receptores de Inositol 1,4,5-Trifosfato , Péptidos y Proteínas de Señalización Intracelular , Isoenzimas/metabolismo , Ratones , Mutación , Fosfolipasa C gamma , Plásmidos/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Pirrolidinonas/farmacología , Receptores de Antígenos de Linfocitos B/metabolismo , Receptores Citoplasmáticos y Nucleares/fisiología , Quinasa Syk , Canales Catiónicos TRPC , Factores de Tiempo , Transfección , Fosfolipasas de Tipo C/metabolismo , WortmaninaRESUMEN
Research was conducted to determine the effects of supplemental dietary vitamin D3 on DMI, carcass traits, Warner Bratzler shear (WBS) force, calpastatin activity, plasma minerals, pH (0, 3, 12, and 24 h after slaughter), water-holding capacity (WHC), and sensory characteristics of three muscles. Pre-slaughter vitamin D3 treatments included no supplemental vitamin D3, 6 x 106 IU (MIU) of vitamin D3 for 4 d, or 6 MIU of vitamin D3 for 6 d. Cattle were slaughtered and carcasses were chilled for 48 h before removal of steaks from the longissimus, gluteus medius, and biceps femoris muscles. Steaks were aged at 2 degrees C for 7, 14, or 21 d before cooking to a final internal temperature of 70 degrees C for WBS and sensory panel analysis. Dry matter intake was lower for steers supplemented with vitamin D3 for 4 or 6 d. Live and carcass weights were lower (P < 0.05) in steers supplemented with vitamin D3. Supplementing 6 MIU/6 d of vitamin D3 decreased (P < 0.05) WBS values of gluteus steaks (pooled over aging times). Longissimus steaks from steers supplemented with vitamin D3 for 6 d had lower (P < 0.05) WBS force values than these steaks from control steers or steers fed vitamin D3 for 4 d at 7 d postmortem. Biceps femoris steaks from steers receiving vitamin D3 for 4 d had higher WBS values than steaks from control steers at 14 and 21 d postmortem. Feeding vitamin D3 at 6 MIU for 6 d decreased (P < 0.05) the percentage of steaks that had WBS values > or = 3.86 kg for all steaks. Feeding vitamin D3 had no effect on palatability traits evaluated by trained panelists. Blood Ca concentrations were greater (P < 0.05) when vitamin D3 was fed and with increased vitamin D3 feeding time. Feeding vitamin D3 for 6 d (vs 4 d) delayed pH decline for all muscle types after 0, 3, and 12 h postmortem. Water-holding capacity was increased (P > 0.02) after 0 h, 24 h, and 21 d postmortem when vitamin D3 was fed and was greater at 0 and 24 h if vitamin D3 was fed for 6 d rather than 4 d. These data suggest that supplementing 6 MIU of vitamin D3 will decrease DMI and improve beef tenderness through increased blood plasma Ca concentrations and WHC.
Asunto(s)
Peso Corporal/efectos de los fármacos , Bovinos/fisiología , Colecalciferol/administración & dosificación , Ingestión de Energía/efectos de los fármacos , Carne/normas , Músculo Esquelético/metabolismo , Animales , Calcio/sangre , Proteínas de Unión al Calcio/metabolismo , Bovinos/anatomía & histología , Colecalciferol/farmacología , Inhibidores de Cisteína Proteinasa/metabolismo , Relación Dosis-Respuesta a Droga , Manipulación de Alimentos , Masculino , Carne/análisis , Músculo Esquelético/efectos de los fármacos , Cambios Post Mortem , Distribución Aleatoria , Gusto , Factores de TiempoRESUMEN
A 59-year-old man presented with a psoriasiform dermatitis with associated bullae and destructive nail dystrophy of the hands and feet. He had lost 10 kg weight over 6 months and a mass in the neck was noted. He was provisionally diagnosed with Bazex syndrome (acrokeratosis paraneoplastica) and subsequent investigations revealed a squamous cell carcinoma in the right piriform fossa. His skin lesions were treated with oral psoralen and ultraviolet A phototherapy and this cleared the cutaneous changes, but the nail changes have persisted at 18 months follow up.
Asunto(s)
Carcinoma de Células Escamosas/terapia , Ficusina/uso terapéutico , Neoplasias de Cabeza y Cuello/terapia , Terapia PUVA/métodos , Síndromes Paraneoplásicos/terapia , Fármacos Fotosensibilizantes/uso terapéutico , Acrodermatitis/patología , Acrodermatitis/terapia , Administración Oral , Biopsia , Carcinoma de Células Escamosas/complicaciones , Carcinoma de Células Escamosas/patología , Neoplasias de Cabeza y Cuello/complicaciones , Neoplasias de Cabeza y Cuello/patología , Humanos , Queratosis/patología , Queratosis/terapia , Masculino , Persona de Mediana Edad , Síndromes Paraneoplásicos/complicaciones , Síndromes Paraneoplásicos/patologíaRESUMEN
The objectives of these experiments were to determine 1) the effectiveness of supplemental vitamin D3 (VITD) on altering plasma and muscle calcium levels, 2) whether VITD supplementation improves Warner-Bratzler shear force (WBS) values of steaks from feedlot beef steers, and 3) the tenderness response curve of longissimus steaks from steers supplemented with VITD. In Exp. 1, 20 crossbred steers were assigned randomly to one of four treatment diets consisting of either 0, 2.5, 5.0, or 7.5 x 106 IU of VITD per day for 10 d. Blood samples were obtained daily during this supplementation period and 5 d thereafter (d 11 to 15). Between d 6 and 13, a linear increase (P < .01) in ionized plasma calcium concentrations was observed in steers supplemented with VITD. Compared to unsupplemented steers, serum calcium concentrations of the steers receiving 7.5 x 106 IU of VITD per day were increased 8 to 48%. In Exp. 2, longissimus samples from crossbred steers (n = 118) that were supplemented with either 0 or 5 x 106 IU of VITD per day for 7 d were obtained and aged for 7, 14, or 21 d. Following the initial 7-d postmortem aging period, VITD supplementation lowered (P < .01) WBS (.58 kg) and increased sensory tenderness rating (.6 units) compared to cuts originating from unsupplemented steers. In Exp. 3, 44 steers were supplemented with either 0 or 7.5 x 106 IU of VITD per day for 10 d immediately prior to slaughter. Results indicated that plasma and longissimus calcium concentration were higher (P < .05) for steers that received supplemental VITD. Compared with unsupplemented cuts, VITD supplementation improved WBS of cuts aged for either 7 or 14 d (P = .02 and P = .07, respectively). Sensory panelists rated samples from VITD supplemented steers as more tender than their unsupplemented counterparts. Activation of calpain proteases could be responsible for the observed tenderization due to the supplementation of VITD.
Asunto(s)
Alimentación Animal , Bovinos/anatomía & histología , Colecalciferol/administración & dosificación , Suplementos Dietéticos , Carne/normas , Músculo Esquelético/anatomía & histología , Animales , Calcio/sangre , Calcio/metabolismo , Calpaína/metabolismo , Bovinos/metabolismo , Masculino , Músculo Esquelético/metabolismo , Estrés MecánicoRESUMEN
Six-month-old infants were recruited at 21 centres in the UK and Ireland and randomly assigned to receive matching iron-fortified (12.3 mg/l iron) or non-fortified (1.4 mg/l iron) formula for 9 months. Infants already receiving cow's milk continued this feed. Haematological indices and iron status were evaluated at age 6 months, 9-10 months and 15 months. Four hundred and six infants entered and 302 completed the study. There were no differences between the groups for increases in weight, head circumference or length. Significant differences between the groups were observed at 15 months for haemoglobin, serum ferritin, serum iron and total iron binding capacity. Haemoglobin levels were < 110 g/l in 33% of infants fed cow's milk compared with 13% and 11% in those receiving non-iron-fortified and iron-fortified formula respectively. The corresponding figures for serum ferritin < 10 microg/l were 43%, 22% and 6%. Follow-on formula provides an acceptable vehicle for preventing iron deficiency in this vulnerable group.
Asunto(s)
Anemia Ferropénica/prevención & control , Ferritinas/sangre , Alimentos Fortificados , Hierro/administración & dosificación , Leche , Anemia Ferropénica/dietoterapia , Anemia Ferropénica/fisiopatología , Animales , Recuento de Eritrocitos , Femenino , Humanos , Técnicas para Inmunoenzimas , Lactante , Alimentos Infantiles , Irlanda , Hierro/sangre , Masculino , Resultado del Tratamiento , Reino UnidoAsunto(s)
Medicina Basada en la Evidencia/tendencias , Trastornos Psicofisiológicos/terapia , Medicina Psicosomática/tendencias , Predicción , Humanos , Guías de Práctica Clínica como Asunto , Trastornos Psicofisiológicos/psicología , Garantía de la Calidad de Atención de Salud , Resultado del TratamientoRESUMEN
Dental students are encouraged to undertake elective study overseas to increase their clinical experience with diseases that are uncommon in the UK. India has a high incidence of oral cancer and precancer and is an ideal destination for students interested in the study of malignant oral disease. This article reports the findings of a student on elective study to India.
Asunto(s)
Carcinoma de Células Escamosas/epidemiología , Neoplasias de la Boca/epidemiología , Lesiones Precancerosas/epidemiología , Areca , Carcinoma de Células Escamosas/etiología , Educación en Odontología , Humanos , Incidencia , India/epidemiología , Mucosa Bucal/patología , Neoplasias de la Boca/etiología , Plantas Medicinales , Plantas Tóxicas , Lesiones Precancerosas/etiología , Prevalencia , Tabaco sin Humo/efectos adversosRESUMEN
The intracellular Ca2+ pump blocker, thapsigargin, induces emptying of Ca2+ pools and entry of DDT1MF-2 smooth muscle cells into a quiescent G(0)-like growth state. Although thapsigargin blocks pumps essentially irreversibly, high serum (20%) induces appearance of new pump protein, return of functional pools, and reentry of cells into the cell cycle (Waldron, R. T., Short, A. D., Meadows, J.J., Ghosh, T. K., and Gill, D. L. (1994) J. Biol. Chem. 269, 11927-11933). Through analysis of the effects of defined serum components and growth supplements, we reveal here that the factors in serum responsible for inducing recovery of Ca2+ pools and growth in thapsigargin-arrested DDT1MF-2 cells are exactly mimicked by the three essential fatty acids, arachidonic, linoleic, and alpha-linolenic acids. The EC50 values for arachidonic and linoleic acids on growth induction of thapsigargin-arrested cells were the same, approximately 5 microM. Nonessential fatty acids, including myristic, palmitic, stearic, oleic, and arachidic acids, were without any effect. Although not proven to be the active component of serum, levels of arachidonic and linoleic acids in serum were sufficient to explain serum-induced growth recovery. Significantly, arachidonic or linoleic acids induced complete recovery of bradykinin-sensitive Ca2+ pools within 6 h of treatment of thapsigargin-arrested cells. Protein synthesis inhibitors (cycloheximide or puromycin) completely blocked the appearance of serum-induced or arachidonic acid-induced agonist-sensitive pools. The sensitivity and fatty acid specificity of Ca2+ pool recovery in thapsigargin-arrested cells were almost identical to that for growth recovery. No pool or growth recovery was observed with 5,8,11,14-eicosatetraynoic acid, the nonmetabolizable analogue of arachidonic acid, suggesting that conversion to eicosanoids underlies the pool and growth recovery induced by essential fatty acids. The results provide not only further information on the link between Ca2+ pools and cell growth but also evidence for a potentially important signaling pathway involved in inducing transition from a stationary to a proliferative growth state.
Asunto(s)
Ácido Araquidónico/farmacología , Calcio/metabolismo , Músculo Liso/metabolismo , Animales , Ácido Araquidónico/metabolismo , División Celular , Células Cultivadas , Cricetinae , Medios de CultivoRESUMEN
RCTs are the gold standard for the evaluation of mental health care [WHO Scientific Group on Treatment of Psychiatric Disorders, 1991]. All RCTs in the Journal of Psychosomatic Research to date (October 1993) were identified. A profile of the geographical origin, content, interventions under investigation, and methodological quality (as measured by reporting of randomization) of every trial is described. The prevalence of trials from Europe in the Journal is increasing. The frequency of trials regarding the psychotherapies in this journal is also increasing whilst that of drug trials is constant. High quality reporting of randomization is rare. This pilot study generates many disturbing questions regarding the content and quality of RCTs within psychosomatic medicine that urgently need to be answered. Trials in this journal may well not be representative of all RCTs relevant to psychosomatic medicine. If all such trials are to be made accessible to those interested in evidence-based practice, however, much methodical searching must be undertaken, and this study can then be repeated and the questions answered with more authority.
Asunto(s)
Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Humanos , MEDLINE , Medicina Psicosomática/estadística & datos numéricos , Proyectos de Investigación/estadística & datos numéricosRESUMEN
The purpose of this investigation was twofold: (a) to compare most and least economical runners on use of attentional strategies and (b) to determine whether the least economical runners within the subject sample could improve running economy (RE) with the use of an active associative (relaxation) attentional strategy. Subjects (N = 36) completed an initial assessment of attentional style and RE; then the 12 least economical runners ran in each of three laboratory sessions using control, passive associative, and active associative attentional strategies. Results showed that the most economical and least economical runners did not differ in associative style use. The most economical runners, however, reported less dissociation use and more use of relaxation than did the least economical runners. No significant physiological or psychological changes were associated with any of the three attentional strategy conditions. The findings are related to possible differences in how most and least economical runners use associative strategies.
Asunto(s)
Atención , Carrera/psicología , Adolescente , Adulto , Aprendizaje por Asociación , Femenino , Humanos , Masculino , Consumo de Oxígeno , Terapia por Relajación , Carrera/fisiologíaRESUMEN
Beta-hydroxy-beta-methyl butyrate (HMB), a compound formed during catabolism of leucine, was fed to 256 crossbred steers as 0 or .03% of diet dry matter. Effects on performance, carcass characteristics, and tissue composition were measured. Groups of 32 steers per diet were slaughtered after 105, 119, 133, and 147 d on feed. The HMB was fed to each group only during the final 82 d they were fed. Averaged across slaughter date, animal performance was not altered by HMB; however, an interaction between HMB and time on feed was detected. Feeding HMB increased (P < .01) daily gain of steers slaughtered at 105 d but decreased (P < .01) daily gain of steers slaughtered at 147 d. Steers fed HMB had numerically higher marbling scores that resulted in a trend toward higher carcass quality grades. Steers receiving HMB tended to have less (P < .08) s.c. fat and fewer steers with yield grades of 4 or greater (1.6 vs 4.7%). Supplementation of HMB to feedlot steers tended to increase (P < .07) the ratio of intramuscular fat to subcutaneous fat. Steers fed HMB had higher (P < .001) blood plasma concentrations of HMB (3.06 vs 1.70 mg/L) and lower (P < .03) blood plasma concentrations of cholesterol (108.4 vs 118.7 mg/dL). Feeding HMB tended to increase (P < .10) lipid content of the longissimus muscles of those steers slaughtered at 105 d.
Asunto(s)
Composición Corporal/efectos de los fármacos , Bovinos/crecimiento & desarrollo , Carne/normas , Valeratos/farmacología , Tejido Adiposo/efectos de los fármacos , Animales , Bovinos/sangre , Colesterol/sangre , Ingestión de Alimentos/efectos de los fármacos , Cetoácidos/sangre , Masculino , Músculo Esquelético/química , Músculo Esquelético/efectos de los fármacos , Distribución Aleatoria , Valeratos/sangre , Aumento de Peso/efectos de los fármacosRESUMEN
The cystic fibrosis gene product, CFTR, and the multidrug resistance P-glycoprotein (encoded by the MDR1 gene) are structurally related proteins and both are associated with epithelial chloride channel activities. We have compared their cell-specific expression in the rat by in situ hybridization. In all tissues examined the two genes were found to have complementary patterns of expression, demonstrating exquisite regulation in both cell-specific and temporal fashions. Additionally, a switch in expression from one gene to the other was observed in certain tissues. For example, expression in the intestine switches from CFTR to MDR1 as the cells migrate across the crypt-villus boundary. A switch from CFTR to MDR1 expression was also observed in the uterine epithelium upon pregnancy. These data suggest that CFTR and P-glycoprotein serve analogous roles in epithelial cells and provide additional evidence that P-glycoprotein has a physiological role in regulating epithelial cell volume. The patterns of expression suggest that the regulation of these two genes is coordinately controlled.
Asunto(s)
Fibrosis Quística/genética , Resistencia a Medicamentos/genética , Regulación de la Expresión Génica , Glicoproteínas de Membrana/genética , Proteínas de la Membrana/genética , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP , Animales , Secuencia de Bases , Canales de Cloruro , Regulador de Conductancia de Transmembrana de Fibrosis Quística , Desarrollo Embrionario y Fetal/genética , Epitelio/metabolismo , Femenino , Hibridación in Situ , Mucosa Intestinal/metabolismo , Masculino , Proteínas de la Membrana/metabolismo , Datos de Secuencia Molecular , Placenta/metabolismo , Embarazo , Sondas ARN , Ratas , Ratas Wistar , Testículo/metabolismo , Útero/metabolismoRESUMEN
The iron and nutritional status of 22 clinically well and normal toddlers, aged from one to four years inclusive was determined. Mean energy intake was normal. Protein, fibre and ascorbic acid intakes were high. Total iron intake was low in 73%, and available iron was low in 96%. The percentage availability of the total iron intake was 6.98 +/- 1.2, which is below the 10% assumption of iron availability based on consumption of the recommended daily allowances. Mean haemoglobin was with in the normal range. Low normal serum ferritin suggested poor iron stores. Anthropometric measurements were normal. Although the toddlers; intake of most dietary parameters was normal, the finding of poor iron intake and stores is of concern given recent reports of the role of iron in weight gain and psychomotor development.
Asunto(s)
Fenómenos Fisiológicos Nutricionales Infantiles , Fenómenos Fisiológicos Nutricionales del Lactante , Hierro/sangre , Preescolar , Dieta , Humanos , Lactante , Irlanda , Deficiencias de Hierro , Estado Nutricional , Valor Nutritivo , Distribución Aleatoria , Encuestas y CuestionariosRESUMEN
Thirty-six patients with primary biliary cirrhosis (PBC) receiving calcium and calciferol supplements (100,000 IU monthly by im injection) were investigated for their calcium, vitamin D, PTH, and osteocalcin status. The corrected plasma calcium concentrations in PBC patients were significantly greater than those in normal subjects. While the mean serum 25-hydroxycholecalciferol and 1,25-dihydroxyvitamin D concentrations in these patients were similar to those in normal subjects, the mean serum PTH concentration was significantly greater, and it was supranormal in 11 patients. Three patients had elevated corrected calcium concentrations; 1 of them had a concomitant increase in ionized calcium and a supranormal PTH level, and another had a high normal PTH. Ionized calcium concentrations were normal in the rest. Serum osteocalcin concentrations were significantly lower in the patients compared with those in normal subjects. These results indicate that PTH concentrations are frequently elevated in PBC patients despite adequate vitamin D supplementation and normal or even supranormal plasma calcium concentrations. Nonsuppression of PTH concentrations and autonomy of PTH secretion suggest that vitamin D deficiency and secondary hyperparathyroidism in such patients probably occur much earlier in the natural history of this disease than is currently realized. Persistent nonsuppressible hypersecretion of PTH probably contributes to the bone disease of primary biliary cirrhosis. The low osteocalcin concentrations probably reflect diminished osteoblastic activity, which may also contribute to osteopenia in these patients.
Asunto(s)
Proteínas de Unión al Calcio/sangre , Ergocalciferoles/uso terapéutico , Hiperparatiroidismo/etiología , Cirrosis Hepática Biliar/complicaciones , Adulto , Anciano , Calcifediol/sangre , Calcitriol/sangre , Calcio/sangre , Calcio/uso terapéutico , Femenino , Humanos , Hiperparatiroidismo/sangre , Cirrosis Hepática Biliar/sangre , Cirrosis Hepática Biliar/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Osteocalcina , Hormona Paratiroidea/sangreRESUMEN
Cucumber seedlings infected with cucumber mosaic virus (CMV) contain a virus-induced RNA-dependent RNA polymerase (RNA replicase) in both soluble and particulate fractions of plant extracts; no such activity is found in uninfected plants. The extensive purification and characterization of the soluble RNA replicase has been described (R. Kumarasamy and R. H. Symons, 1979, Virology 96, 622-632) while the characterization of the particulate enzyme is reported here. The particulate RNA replicase was solubilized-by incubation in 150 mM MgS04 at 37 degrees for 5 min; both magnesium and sulfate ions were required for maximum release. Only 5-7% of the protein of the particulate fraction was released under these conditions either in the presence or absence of a variety of salts. The solubilized enzyme was purified about 60-fold by a three-step procedure to a specific activity similar to that of the 10,000-fold purified soluble enzyme. CMV RNA and poly(C)-copying activities copurified through the three steps. Purification was followed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate of the in vitro 3H-labeled proteins. The most prominent virus-induced components were two proteins of Mr 100,000 and 110,000 which correspond in size to two virus-induced proteins in the extensively purified soluble RNA replicase. The Mr 110,000 protein comigrated with the full length in vitro translation product of CMV RNA 2 while the Mr 100,000 was detectably larger than the full length in vitro translation product of CMV RNA 1.
RESUMEN
Fluorescence spectroscopy and electron microscopic techniques have been employed to investigate a class of glial cells that is characterized by the presence in their cytoplasm of large fluorescing inclusions that stain with paraldehyde-fuchsin or chrome-hematoxyline-alum. In the periventricular nucleus the cells have been identified as a population of astrocytes whose inclusions emit an orange-red fluorescence. In the arcuate nucleus there are, in addition to an overwhelming majority of such astrocytes, also some microglial cells with similar characteristics. The ability of the latter to emit any kind of fluorescence has not yet been established. The fluorescence maximum of these astrocytic inclusions was found to be at 640 nm when excited at 405 nm. The data obtained suggest that the fluorescence observed is due to the presence of porphyrins in the astrocytic inclusions. In the majority of our electron microscopic pictures the inclusions lack a bounding membrane. By contrast, neuronal lipofuscin has an outer membrane. In cryostat sections, the lipofuscin emits a yellow fluorescence when excited at 400-410 nm.