Rapid identification of Actinomycetaceae and related bacteria. (9/4345)

Identification of new isolates belonging to the family Actinomycetaceae requires extensive numbers of biochemical tests, supplemented with gas-liquid chromatography determination of fermentation end products and, often, analysis of cell wall composition. This paper describes the results of the testing of 162 strains of Actinomycetaceae and related taxa for 20 different enzymatic activities including phosphatases, esterases, aminopeptidases, and glycosidases. The results of all tests were read after 4 h of incubation. The results obtained in the study provide significant new information on the biochemical properties of these groups of bacteria. An identification scheme based upon 13 selected tests, which allow the identification of these groups of bacteria within 4 h, is proposed.  (+info)

Identification of Rickettsia rickettsii in formalin-fixed, paraffin-embedded tissues by immunofluorescence. (10/4345)

With slight modification of a trypsin digestion technique, Rickettsia rickettsii were demonstrated specifically by immunofluorescence staining in Formalin-fixed, paraffin-embedded tissue sections from a human, rhesus monkey, and guinea pig with Rocky Mountain spotted fever and in infected membranes from a chicken embryo. Tissues were cut at 4 micron and, using geltain as a tissue adhesive, were hydrated in a routine manner. Sections were then digested in refrigerated 0.1% trypsin for 16 h, washed, and stained specifically for R. rickettsii by direct or indirect immunofluorescence. Rickettsial organisms were localized in affected vessels of the mammalian species and within the yolk sac epithelium of the chicken embryo. Specificity was confirmed by adsorbing antibody conjugates with R. rickettsii organisms. Trypsin digestion probably decreased tissue proteins which interfered with immunochemical attachment of antibody to the rickettsiae. The technique is valuable in that a diagnosis of Rocky Mountain spotted fever can be confirmed from Formalin-fixed tissues processed in a routine manner.  (+info)

Evidence for an adenovirus type 2-coded early glycoprotein. (11/4345)

We have identified an adenovirus type 2 (Ad2)-induced early glycopolypeptide with an apparent molecular weight of 20,000 to 21,000 (20/21K), as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The 20/21K polypeptide could be labeled in vivo with [(3)H]glucosamine. [(35)S]methionine- and [(3)H]-glucosamine-labeled 20/21K polypeptides bound to concanavalin A-Sepharose columns and were eluted with 0.2 M methyl-alpha-d-mannoside. The pulse-labeled polypeptide appeared as a sharp band with an apparent molecular weight of 21K, but after a chase it converted to multiple bands with an average molecular weight of 20K. This variability in electrophoretic mobility is consistent with glycosylation or deglycosylation of the 20/21K polypeptide. Analysis of the pulse and pulse-chase-labeled forms by using partial proteolysis indicated that the polypeptides were highly related chemically, but not identical. Most of the 20/21K polypeptide is localized in the cytoplasm fraction of infected cells lysed by Nonidet P-40. The 20/21K polypeptide and a 44K polypeptide, labeled with [(35)S]methionine or [(3)H]glucosamine in Ad2-infected human cells, were precipitated by a rat antiserum against an Ad2-transformed rat cell line (T2C4), but not by antisera against three other Ad2-transformed rat cell lines, or by serum from nonimmune rats. The partial proteolysis patterns of the 20/21K and the 44K polypeptides were indistinguishable, indicating that the two polypeptides are highly related, and suggesting that the 44K polypeptide might be a dimer of the 20/21K polypeptide. The 20/21K polypeptide was also induced in Ad2-early infected monkey and hamster cells. These results imply that the 20/21K polypeptide is synthesized in Ad2-infected human, monkey, and hamster cells, and in one but not all Ad2-transformed rat cells. Thus, the 20/21K polypeptide is probably viral coded rather than cell coded and viral induced.  (+info)

Altered pharmacokinetics of a novel anticancer drug, UCN-01, caused by specific high affinity binding to alpha1-acid glycoprotein in humans. (12/4345)

The large species difference in the pharmacokinetics/pharmacodynamics of 7-hydroxystaurosporine (UCN-01) can be partially explained by the high affinity binding of UCN-01 to human alpha1-acid glycoprotein (AGP) (Fuse et al, Cancer Res., 58: 3248-3253, 1998). To confirm whether its binding to human AGP actually changes the in vivo pharmacokinetics, we have studied the alteration in its pharmacokinetics after simultaneous administration of human AGP to rats: (a) the protein binding of UCN-01 was evaluated by chasing its dissociation from proteins using dextran-coated charcoal. The UCN-01 remaining 0.1 h after adding dextran-coated charcoal to human plasma or AGP was approximately 80%, although the values for other specimens, except monkey plasma (approximately 20%), were <1%, indicating that the dissociation from human AGP was specifically slower than from other proteins; and (b) the pharmacokinetics of UCN-01 simultaneously administered with human AGP has been determined. The plasma concentrations after i.v. administration of UCN-O1 with equimolar human AGP were much higher than those after administration of UCN-01 alone. The steady-state distribution volume and the systemic clearance were reduced to about 1/100 and 1/200, respectively. Human AGP thus reduced the distribution and elimination of UCN-01 substantially. On the other hand, dog AGP, which has a low binding affinity for UCN-01, did not change the pharmacokinetics of UCN-01 so much. Furthermore, human AGP markedly reduced the hepatic extraction ratio of UCN-01 from 0.510 to 0.0326. Also, human AGP (10 microM) completely inhibited the initial uptake of UCN-01 (1 microM) into isolated rat hepatocytes, whereas the uptake of UCN-01 was unchanged in the presence of human serum albumin (10 microM). In conclusion, the high degree of binding of UCN-01 to human AGP causes a reduction in the distribution and clearance, resulting in high plasma concentrations in humans.  (+info)

Motor cortical encoding of serial order in a context-recall task. (13/4345)

The neural encoding of serial order was studied in the motor cortex of monkeys performing a context-recall memory scanning task. Up to five visual stimuli were presented successively on a circle (list presentation phase), and then one of them (test stimulus) changed color; the monkeys had to make a single motor response toward the stimulus that immediately followed the test stimulus in the list. Correct performance in this task depends on memorization of the serial order of the stimuli during their presentation. It was found that changes in neural activity during the list presentation phase reflected the serial order of the stimuli; the effect on cell activity of the serial order of stimuli during their presentation was at least as strong as the effect of motor direction on cell activity during the execution of the motor response. This establishes the serial order of stimuli in a motor task as an important determinant of motor cortical activity during stimulus presentation and in the absence of changes in peripheral motor events, in contrast to the commonly held view of the motor cortex as just an "upper motor neuron."  (+info)

Prenatal nicotine increases pulmonary alpha7 nicotinic receptor expression and alters fetal lung development in monkeys. (14/4345)

It is well established that maternal smoking during pregnancy is a leading preventable cause of low birth weight and prematurity. Less appreciated is that maternal smoking during pregnancy is also associated with alterations in pulmonary function at birth and greater incidence of respiratory illnesses after birth. To determine if this is the direct result of nicotine interacting with nicotinic cholinergic receptors (nAChRs) during lung development, rhesus monkeys were treated with 1 mg/kg/day of nicotine from days 26 to 134 of pregnancy. Nicotine administration caused lung hypoplasia and reduced surface complexity of developing alveoli. Immunohistochemistry and in situ alpha-bungarotoxin (alphaBGT) binding showed that alpha7 nAChRs are present in the developing lung in airway epithelial cells, cells surrounding large airways and blood vessels, alveolar type II cells, free alveolar macrophages, and pulmonary neuroendocrine cells (PNEC). As detected both by immunohistochemistry and by alphaBGT binding, nicotine administration markedly increased alpha7 receptor subunit expression and binding in the fetal lung. Correlating with areas of increased alpha7 expression, collagen expression surrounding large airways and vessels was significantly increased. Nicotine also significantly increased numbers of type II cells and neuroendocrine cells in neuroepithelial bodies. These findings demonstrate that nicotine can alter fetal monkey lung development by crossing the placenta to interact directly with nicotinic receptors on non-neuronal cells in the developing lung, and that similar effects likely occur in human infants whose mothers smoke during pregnancy.  (+info)

Stimulated changes in localized cerebral energy consumption under anesthesia. (15/4345)

Focal changes in the cerebral metabolic rate of glucose utilization (CMRglc) are small (10-40%) during sensory activation in awake humans, as well as in awake rodents and primates (20-50%). They are significantly larger (50-250%) in sensory activation studies of anesthetized rats and cats. Our data, in agreement with literature values, show that in the resting anesthetized state values of CMRglc are lower than in the resting nonanesthetized state whereas the final state values, reached upon activation, are similar for the anesthetized and nonanesthetized animals. The lower resting anesthetized state values of CMRglc explain why the increments upon activation from anesthesia are larger than when starting from the nonanesthetized conditions. Recent 13C NMR measurements in our laboratory have established a quantitative relationship between the energetics of glucose oxidation, CMRglc (oxidative), and the flux of the glutamate/gamma-aminobutyric acid/glutamine neurotransmitter cycle, Vcycle. In both the resting awake value of CMRglc(oxidative), and its increment upon stimulation, a large majority (approximately 80%) of the brain energy consumption is devoted to Vcycle. In the differencing methods of functional imaging, it is assumed that the incremental change in the measured signal represents the modular activity that supports the functional response. However, the same amount of activity must be present during the response to stimulation, irrespective of the initial basal state of the cortex. Thus, whereas the incremental signals of DeltaCMRglc can localize neurotransmitter activity, the magnitude of such activity during the response is represented by the total localized CMRglc, not the increment.  (+info)

Synapses involving auditory nerve fibers in primate cochlea. (16/4345)

The anatomical mechanisms for processing auditory signals are extremely complex and incompletely understood, despite major advances already made with the use of electron microscopy. A major enigma, for example, is the presence in the mammalian cochlea of a double hair cell receptor system. A renewed attempt to discover evidence of synaptic coupling between the two systems in the primate cochlea, postulated from physiological studies, has failed. However, in the outer spiral bundle the narrow and rigid clefts seen between pairs of presumptive afferent fibers suggest the possibility of dendro-dendritic interaction confined to the outer hair cell system. The clustering of afferent processes within folds of supporting cells subjacent to outer hair cells is in contrast to the lack of such close associations in the inner hair cell region. The difference reinforces the suggestion of functional interaction of some sort between the outer hair cell afferent nerve processes.  (+info)