RESUMEN
We describe a novel erythroid cell-specific cDNA (EKLF [erythroid Krüppel-like factor]) isolated by enriching for genes expressed in a mouse erythroleukemia cell line but not expressed in a mouse monocyte-macrophage cell line. The complete cDNA sequence is predicted to encode a protein of approximately 38,000 Da that contains a proline-rich amino domain and three TFIIIA-like zinc fingers within the carboxy domain. Additional sequence analyses reveal that the EKLF zinc fingers are most homologous to the Krüppel family of transcription factors and also allow us to predict potential DNA-binding target sites for the EKLF protein. On the basis of this prediction, we show that EKLF is able to bind the sequence CCA CAC CCT, an essential element of the beta-globin promoter. Its tissue distribution establishes that the EKLF transcript is expressed only in bone marrow and spleen, the two hematopoietic organs of the mouse, and analysis of murine cell lines indicates that EKLF expression is limited to erythroid and mast cell lines. Cotransfection assays establish that EKLF transcriptionally activates a target promoter that contains its DNA-binding site. The tissue expression pattern of EKLF, in conjunction with its function as a transcriptional activator, strongly suggests that the EKLF protein may be intimately involved in establishment and/or maintenance of the erythroid cell phenotype.
Asunto(s)
Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Represoras , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Northern Blotting , Línea Celular , Mapeo Cromosómico , Cricetinae , Proteínas de Unión al ADN/aislamiento & purificación , Células Híbridas , Factores de Transcripción de Tipo Kruppel , Leucemia Eritroblástica Aguda , Macrófagos , Ratones , Datos de Secuencia Molecular , Proteínas Nucleares/genética , Oligodesoxirribonucleótidos , Oligonucleótidos Antisentido , Reacción en Cadena de la Polimerasa , ARN/genética , ARN/aislamiento & purificación , Homología de Secuencia de Aminoácido , Especificidad por Sustrato , Factores de Transcripción/aislamiento & purificación , Células Tumorales Cultivadas , Dedos de Zinc/genética , Dedos de Zinc/fisiologíaRESUMEN
Recordings were made from single fibers of the rat chorda tympani nerve while the peripheral receptor fields were mapped using a stimulator developed to stimulate single fungiform papillae which in the rat contain a solitary taste bud. The results indicate that several fungiform papillae may supply input to a single fiber, and the most sensitive papilla of these provided, on the average, about one-half of the response of that fiber to stimulation of the entire tongue. The magnitude of the response to each concentration of stimulus and the shape of the concentration-response curves differ among papillae innervated by the same fiber. If one of the papillae supplying input to the fiber was stimulated individually with NaCl solution, application of this stimulus to the tongue surface surrounding the isolated papilla resulted in enhancement of the fiber response. If the papilla was stimulated with NaCl and potassium benzoate solution was applied to the surround, a depression of the response occurred. The excitatory input of the cationic stimuli and the depressing influence of the anionic stimuli interacted to determine the resultant steady-state impulse frequency of the single afferent fiber. A hypothetical model involving the summation of generator currents along the unmyelinated terminals of the single afferent neuron is presented as a speculative explanation of the integration of inputs from several receptors innervated by the same single fiber.
Asunto(s)
Nervio de la Cuerda del Tímpano/fisiología , Papilas Gustativas/inervación , Papilas Gustativas/fisiología , Lengua/inervación , Potenciales de Acción , Animales , Benzoatos/farmacología , Nervio de la Cuerda del Tímpano/anatomía & histología , Depresión Química , Femenino , Masculino , Fibras Nerviosas Mielínicas/fisiología , Neuronas Aferentes/fisiología , Ratas , Cloruro de Sodio/farmacología , Estimulación Química , Lengua/fisiologíaRESUMEN
Forty-six renal donors who responded to a questionnaire and two additional donors with nephrotic syndrome and renal insufficiency were studied. The mean age was 46 +/- 2.0 years (mean +/- SE). Duration of follow-up was 6 +/- 0.5 years. Serum creatinine levels increased from 1.0 +/- 0.03 mg/dl before donation to 1.2 +/- 0.04 mg/dl at follow-up. The incidence of proteinuria (more than 150 mg over 24 hours) was 39 percent. The serum creatinine level was 1.0 +/- 0.08 mg/dl and 1.2 +/- 0.06 mg/dl in the proteinuric and nonproteinuric groups, respectively. The incidence of hypertension was 31 percent with a serum creatinine level of 1.1 +/- 0.11 mg/dl and 1.2 +/- 0.07 mg/dl in the hypertensive and normotensive groups, respectively. One patient with nephrotic syndrome had proliferative glomerulonephritis. It is concluded that renal donation is associated with a minimal but statistically significant increment in serum creatinine levels. The incidence of mild hypertension and proteinuria is increased, but impact on renal function is minimal as assessed by serum creatinine determination.
Asunto(s)
Trasplante de Riñón , Donantes de Tejidos , Adolescente , Adulto , Creatinina/sangre , Femenino , Humanos , Hipertensión/etiología , Masculino , Persona de Mediana Edad , Proteinuria/etiologíaRESUMEN
Taste buds were counted in two strains of mice which have been characterized in terms of their taste avoidance of the bitter-tasting substance, sucrose octaacetate (SOA). One strain (SWR/J) avoids SOA and is referred to as "taster' while the other strain (C57BL/6J) does not avoid SOA at the same concentration and is termed "non-taster'. The taster-strain contains a significantly greater number of taste buds in its vallate papillae than the non-tasters do. The relative number of taste buds which individual mice and humans possess probably contributes to the relative differences in their sensitivity and preference behaviors.
Asunto(s)
Sacarosa/análogos & derivados , Papilas Gustativas/fisiología , Gusto/fisiología , Animales , Ratones , Ratones Endogámicos C57BL , Especificidad de la Especie , Sacarosa/farmacología , Papilas Gustativas/efectos de los fármacosRESUMEN
The localization of the motor neurons to the tensor tympani (TT) muscle was studied using the method of retrograde transport of horseradish peroxidase (HRP). After intramuscular injections of HRP, specifically labeled neurons were found in the ventral, parvocellular portion of the trigeminal motor nucleus. These cells had a medial relation to the rootlets of the trigeminal nerve and, rostrally, to the lateral lemniscus. The results are compared to those of other investigators and a generalization is suggested for the localization of these neurons which allows for species variation. Other incidental findings are also discussed.
Asunto(s)
Músculos Faciales/inervación , Neuronas Motoras/fisiología , Nervio Trigémino/fisiología , Animales , Transporte Axonal , Vías Eferentes/fisiología , Cobayas , Peroxidasa de Rábano Silvestre , Ratas , Especificidad de la EspecieRESUMEN
The distribution of taste buds was examined in hamsters to reveal the sources of convergent neural activity on taste neurons of the medulla and pons. A total of 723 taste buds was found in adult animals. Fungiform papillae contained 130 taste buds (18%). A single vallate papilla had 168 taste buds (23%). There were 230 taste buds (32%) located on bilateral foliate papillae. The palate contained 100 taste buds (14%) divided among the soft palate (88, 12%) and the incisal papilla (12, 2%). On the epiglottis and adjacent region of the esophagus were found 70 taste buds (10%). About 10 taste buds each were located on the buccal wall (1.4%), while the remaining 5 taste buds were found on the sublingual organ. Conclusions about information processing in central neurons of the gustatory system must reflect knowledge of diverse receptor populations and their interactions.
Asunto(s)
Cricetinae/anatomía & histología , Mesocricetus/anatomía & histología , Papilas Gustativas/anatomía & histología , Animales , Mejilla/anatomía & histología , Epiglotis/anatomía & histología , Femenino , Masculino , Hueso Paladar/anatomía & histología , Lengua/anatomía & histologíaRESUMEN
Some variations in human taste sensitivity may be due to different numbers of taste buds among subjects. Taste pores were counted on the tongue tips of 16 people with videomicroscopy, and the subjects were divided into two groups (N = 8) by the rank order of their taste bud densities. The "higher" density group averaged 374 +/- 134 taste pores/cm2, while the "lower" density group averaged 135 +/- 43 tp/cm2. The higher density group had an average fungiform papilla density which was 1.8 times greater than the lower density group and an average of 1.5 times more taste pores/papilla. The subjects also rated the intensity for 4 suprathreshold concentrations of 5 taste stimuli placed on the same region of the tongue where taste pores were counted. The group with higher taste bud densities gave significantly higher average intensity ratings for sucrose (196%), NaCl (135%) and PROP (142%), but not for citric acid (118%) and quinine HCl (110%) than the lower density group. Thus, the subjects with higher fungiform taste bud densities also reported some tastes as more intense than subjects with fewer fungiform taste buds.
Asunto(s)
Papilas Gustativas/anatomía & histología , Umbral Gustativo/fisiología , Gusto/fisiología , Nivel de Alerta/fisiología , Humanos , Lengua/inervaciónRESUMEN
Substitution of deuterium oxide (D2O) as the solvent in taste stimuli elicits neural responses which differ from ordinary water (H2O). Previous reports have shown that D2O is toxic to many animals and rats avoid drinking it when offered H2O simultaneously. In the current study, summated responses were recorded from the chorda tympani nerves of rats after NaCl, KCl, sucrose and quinine were applied to the tongue in solutions of either D2O or H2O. Both solvents were used as the adapting or rinse solution in separate series. On tongues adapted to H2O, D2O elicited mean responses which were equivalent to 29% of the response to 0.1 M NaCl. The threshold concentration of D2O in H2O was between 25% and 50%. Solutes in D2O yielded responses which were greater than corresponding solutions of H2O when adapting rinse was H2O. Adaptation to D2O diminished the responses to D2O solutions of NaCl, KCl and sucrose but not quinine. This observation suggests that some portion of the augmented response to stimuli in D2O is due to the solvent itself. The taste of water has been examined by both electrophysiological methods and by behavior, but none of the mechanisms espoused for its effect seem adequate to explain the response to D2O. Water structure at the interface between molecular components of the cell membrane and the bulk phase of the surrounding medium is considered as a locus for disparity in the taste responses to D2O and H2O in the rat.
Asunto(s)
Deuterio , Gusto/fisiología , Agua , Animales , Nervio de la Cuerda del Tímpano/fisiología , Deuterio/metabolismo , Masculino , Ratas , Agua/metabolismoRESUMEN
Taste worlds of humans vary because of taste blindness to phenylthiocarbamide (PTC) and its chemical relative, 6-n-propylthiouracil (PROP). We review early PTC studies and apply modern statistical analyses to show that a higher frequency of women tasted PTC crystals, and were tasters (threshold classification). In our laboratory, scaling of PROP bitterness led to the identification of a subset of tasters (supertasters) who rate PROP as intensely bitter. Supertasters also perceive stronger tastes from a variety of bitter and sweet substances, and perceive more burn from oral irritants (alcohol and capsaicin). The density of taste receptors on the anterior tongue (fungiform papillae, taste buds) correlate significantly with perceived bitterness of PROP and support the supertaster concept. Psychophysical data from studies in our laboratory also show a sex effect; women are supertasters more frequently. The anatomical data also support the sex difference; women have more fungiform papillae and more taste buds. Future investigations of PTC/PROP tasting and food behaviors should include scaling to identify supertasters and separate sex effects.
Asunto(s)
Feniltiourea , Propiltiouracilo , Gusto/fisiología , Femenino , Humanos , Masculino , Psicofísica , Factores Sexuales , Papilas Gustativas/anatomía & histología , Papilas Gustativas/fisiología , Umbral Gustativo/fisiologíaRESUMEN
The chorda tympani nerve (CT) innervates the fungiform papillae on the tip of the tongue and has been considered an important nerve for the sense of taste. The CT also contains the parasympathetic supply to the submaxillary and sublingual salivary glands. Therefore, changes in taste or feeding behavior following bilateral sections of CT are caused by both degeneration of fungiform papillae and the inevitable partial desalivation of the rat. In the present experiments we compared the effects of bilateral chorda tympani nerve sections with extirpation of submaxillary and sublingual glands on daily home cage eating and drinking patterns in the rat. Before and after surgery we analyzed the daily eating and drinking patterns, including such measures as intake, bout number, bout length, interbout interval and rate of consumption during bouts. The results of desalivation and bilateral CT sections were indistinguishable. The most profound change was that eating bout duration was increased following surgery. Since food intake did not increase, the results indicate a marked loss in eating efficiency over the daily ingestion periods. Although the eating patterns of desalivated and chorda tympani sectioned rats are quite similar, the evidence is not compelling that they have the same physiological basis. A second experiment was designed to test the hypothesis that the atypical eating patterns observed following bilateral sectioning of CT were the direct result of partial desalivation resulting from the denervation of the salivary glands. In this experiment a unilateral section was made of one CT and it was shown that the eating behavior was not affected. Then the contralateral submaxillary and sublingual salivary glands were removed. This resulted in a six-fold increase in feeding bout length. In all cases a unilateral CT section combined with extirpation of the contralateral salivary glands resulted in rats whose eating behavior was indistinguishable from the earlier data following either the bilateral CT sections or bilateral desalivations. The conclusion is drawn that the eating irregularities noted following bilateral CT sections result from this partial desalivation. CT sections were verified by taste bud counts in the fungiform papillae and histological examinations were made of salivary glands in rats receiving CT sections.
Asunto(s)
Nervio de la Cuerda del Tímpano/fisiología , Conducta de Ingestión de Líquido/fisiología , Conducta Alimentaria/fisiología , Lateralidad Funcional/fisiología , Glándula Sublingual/fisiología , Glándula Submandibular/fisiología , Papilas Gustativas/fisiología , Animales , Femenino , Masculino , Sistema Nervioso Parasimpático/fisiología , Ratas , Ratas Endogámicas , Salivación , Glándula Sublingual/inervación , Glándula Submandibular/inervación , Gusto/fisiologíaRESUMEN
The effects of bilateral deafferentation of the greater superficial petrosal (GSP) and the chorda tympani (CT) nerves on the ingestion of sucrose solutions were studied in rats. The rats received five daily sequential 30 second exposures for each sucrose concentration, and the average number of licks per exposure was calculated. Sucrose concentrations of 0.01, 0.03, 0.10, 0.32, and 1.00 M were presented in ascending order across days, both before and after bilateral sectioning of both the CT and the GSP nerves, the CT alone, the GSP alone, or a sham surgery. Prior to surgery, mean lick rate increased with increasing concentrations of sucrose. Following surgery, the rats with combined GSP and CT nerve sections showed a significant decrease in mean rate of licking to the sucrose solutions. The rats with GSP sections showed a similar decrease in mean lick rate to the sucrose solutions. Animals with sections of the CT nerve and sham-operated animals showed no significant reduction in mean lick rate to the sucrose solutions. These results indicate that the GSP nerve is important to the rat in reinforcing high lick rates to sucrose.
Asunto(s)
Nervio de la Cuerda del Tímpano/fisiología , Nervios Craneales/fisiología , Gusto , Animales , Masculino , Hueso Paladar/inervación , Ratas , Ratas Endogámicas , Valores de Referencia , Sacarosa , Lengua/inervaciónRESUMEN
A canine model was used to investigate the efferent laryngeal responses to stimulation by topically applied acid and pepsin. Five adult mongrel dogs were studied. Electromyographic recordings from the thyroarytenoid muscle were measured with hooked-wire electrodes as an acid solution (normal saline/hydrochloric acid at pH 6.0, 5.0, 4.0, 3.0, 2.5, 2.0, 1.5, and 1.0) was sequentially instilled into the larynx. Laryngospasm (tonic, sustained contraction of the thyroarytenoid muscle) occurred in all animals at pH 2.5 to 2.0 or less. Control substances such as neutral pH isotonic saline, hypotonic saline, hypertonic saline, water, and pepsin alone failed to produce laryngospasm. Next, solutions containing both acid (in the same pH range) and pepsin were tested. The laryngeal responses were similar to those of acid alone. The superior laryngeal nerves were sectioned bilaterally and the above experiments repeated. None of the test solutions produced laryngospasm; however, when capsaicin (1%) was instilled into the subglottis, laryngospasm occurred. Thus, chemoreceptors in the subglottis (supplied by the recurrent laryngeal nerves) appear to be responsive to capsaicin stimulation but not to acid stimulation. The data suggest that pH-sensitive chemoreceptors in the canine larynx cause laryngospasm (when the pH of the test solution is 2.5 or less) and that these acid receptors are supplied by the superior laryngeal nerves.
Asunto(s)
Laringismo/fisiopatología , Animales , Células Quimiorreceptoras , Modelos Animales de Enfermedad , Perros , Electromiografía , Concentración de Iones de Hidrógeno , Nervios Laríngeos/fisiología , MasculinoRESUMEN
The highly complex polysaccharide extracted from the New Zealand red alga Pachymenia lusoria (Grev.) J. Ag. has been characterised and certain structural features defined. A reductive hydrolysis procedure was used for constituent sugar and linkage analyses, with trideuteriomethylation being employed to enable the location of natural methyl ether groups to be determined. A reductive partial-hydrolysis procedure allowed agarobiosyl constituent residues to be identified. The analytical results are consistent with the polymer having a linear backbone of 3-linked D-galactopyranosyl alternating with 4-linked D- or L-galactopyranosyl residues. The 3-linked residues are nearly all 2-sulfated, with 1 in 3 also being 6-O-methylated and 1 in 5 also bearing a 4,6-pyruvic acetal residue. About one-third of the polymer is comprised of blocks of agarobiosyl repeat units that are 2-sulfated on the beta-D-galactopyranosyl and one-third 2-O-methylated on the 3,6-anhydro-L-galactosyl constituents. Of the remaining 4-linked residues, half are 2-O-methyl-D-galactopyranosyl residues and half are galactopyranosyl residues, of which approximately half are in the L configuration.
Asunto(s)
Polisacáridos/química , Algas Marinas/química , Espectroscopía de Resonancia Magnética , Estructura Molecular , Polisacáridos/aislamiento & purificaciónRESUMEN
While the communication of empathy is thought to be a curative factor in psychotherapy, current conceptualizations usually focus on empathy as only an attitude or state of mind of the therapist. A five-stage model of therapeutic empathic communication is presented. The model is applied to analyzing the therapeutic impact of empathic communication in dynamic psychotherapy. Its usefulness is demonstrated in a case example.
Asunto(s)
Empatía , Modelos Psicológicos , Psicoterapia/métodos , Adulto , Señales (Psicología) , Femenino , Humanos , Relaciones Profesional-PacienteRESUMEN
The growth of the taste system in the hamster is considered in comparison to the postnatal development of other organ systems and the entire animal. No taste buds are present in vallate or foliate papillae of the hamster at birth, but they attain both the appearance and numbers of adult taste buds within 5 weeks of age. The most rapid increase in the number of taste buds occurs within the first 10 days of life, and this proliferation anticipates the weaning of hamsters which occurs by about three weeks of age. Foliate taste buds reach a maximal number within two months, but vallate taste buds continue to increase in number through 4 months of age. Taste bud proliferation and development occur earlier and more rapidly than in other organ systems. This early development of taste buds may protect the weanling hamster against accidental poisoning by noxious plants, and it may also reinforce the food intake which is required for normal growth.
Asunto(s)
Cricetinae/crecimiento & desarrollo , Mesocricetus/crecimiento & desarrollo , Papilas Gustativas/crecimiento & desarrollo , Animales , Animales Recién Nacidos , Femenino , Nervio Glosofaríngeo/crecimiento & desarrollo , Masculino , Microscopía Electrónica , Ratas , Gusto/fisiologíaAsunto(s)
Medicina Tradicional China , Enfermedades Otorrinolaringológicas/patología , Lengua/patología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Constitución Corporal , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Enfermedades Otorrinolaringológicas/diagnóstico , Encuestas y CuestionariosRESUMEN
Some of the subjective variability attributed to taste experience could be related to wide variations of taste bud density. Studies of taste perception show a direct relationship between sensation and the number of receptors. Taste bud densities are quantified in this study using light microscopy to reconstruct two regions of 18 human cadaver tongues. Specimens came from male and female cadavers representing three age groups: young adults, middle-aged adults, and older adults. The results show a range of more than 100-fold in taste bud density that is evenly distributed among age groups and sexes. The disparity is not attributable to the state of health of the adults prior to death, and it is corroborated in the literature. Differences in taste bud density that extend across age groups probably confound some inferences about the effects of aging on taste sensitivity that are derived from cross-sectional studies of human populations. It is not clear from the data whether or not human taste bud density in individuals and in populations is stable or changing with time.