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121.
The obstructive sleep apnea syndrome is a disorder of sleep and breathing that is being recognized with increasing frequency. The pathophysiologic consequences range from mild sleepiness to life-threatening cardiovascular and respiratory decompensation. The primary forms of treatment are directed at modifying the upper airway with either an operation or continuous positive airway pressure. Aside from tracheostomy, which is virtually always successful, other forms of treatment have met with varying results. Ancillary therapy, including oxygen, weight loss and drugs, is often helpful but seldom curative. Follow-up sleep studies are necessary to evaluate the effectiveness of treatment. Selecting therapy for a patient with obstructive sleep apnea requires a comprehensive evaluation including polysomnography, special examinations of the upper airway and assessing the cardiopulmonary status. Therapy is based on the severity of disease and must be tailored to each patient. 相似文献
122.
We characterized a mutant T -cell lymphoma line selected for the inability to express the Thy-1 glycoprotein. This cell line is a member of the D complementation class of Thy-1– somatic cell mutants, and it lacks detectable cell-surface Thy-1.1 glycoprotein and detectable cytoplasmic Thy-1 mRNA. Southern blot analysis using a number of probes isolated from the clonedThy-1.2 gene demonstrated that, in the mutant, one copy of theThy-1 gene is absent from the genome and the other has undergone rearrangement. This rearrangement results from a deletion of the 5 portion of the gene removing the first two alternate exons and promoters and a portion of the second intron. The deletion breakpoint within the mutantThy-1 gene was localized to within 400 nucleotides by Southern blot analysis. The breakpoint is near two classes of mouse repetitive elements-a mouse B1-family repetitive element and a simple repetitive sequence-suggesting a mechanism of rearrangement leading to the mutation. Southern blot analysis demonstrated that two closely linked molecular markers on chromosome 9 are unaltered, demonstrating that the deletion in this mutant cell line is subchromosomal. 相似文献
123.
Summary Production of trace levels of carbon monoxide was consistently observed in the off-gas of a laboratory anaerobic digester fed Waste Activated Sludge. Inocula from this digester was enriched for acetate and methanol utilizing methanogenic populations. These enriched inocula were then monitored in batch assays for carbon monoxide and hydrogen production. Results demonstrated that carbon monoxide is produced during methanogenesis on both substrates. Subsequent utilization of CO was observed to occur after methane production was essentially complete for the assays conducted with methanol. Carbon monoxide evolution during methanogenesis on acetate displayed a markedly different trend from that observed from methanol. 相似文献
124.
Robert S. Corruccini 《International journal of primatology》1987,8(2):99-114
Dental characteristics figure large in primate taxonomy because teeth fossilize commonly and reflect dietary adaptations.
The mammalian dentinoenamel junction (DEJ) plays a crucial role throughout odontogenesis in determining the ultimate crown
configuration, being the interface between the papilla and the dental cap. The final configuration of the dentin surface reflects
the epithelium more closely than does the enamel surface of the crown. Enamel deposition occurs relatively late in calcification,
often causing many changes from the pattern residing in the DEJ; the genetic determination of the two surfaces also differs.
Comparative study of the DEJ (and its differences from the enamel crown) is a potential adjunct to dentition-based taxonomy
and may help to resolve certain cusp homologies and morphogenetic order of appearance. Primate teeth were stripped of enamel
after measurement, mapping, and anatomical observations on the original crown. The dentin surfaces thus revealed differ from
the enamel surfaces in several respects and shed new light on such dental problem areas as the origin of the hypocone, the
affinities of lorisoids and callitrichids, the monophyly of the anthropoid grade, and human affinities. 相似文献
125.
An external 3.8-MeV proton beam was employed to induce X-rays in 100-mg pellets of human follicular fluids and in 4–8 mg pellets of spermatozoa. The elements Cl, K, Ca, Fe, Cu, Zn, and Br were quantitatively determined in follicular fluids, whereas the elements, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, and Zn were determined in the spermatozoa. Both samples had high interelement Spearman correlation coefficients. Correlations of elements in the samples were observed with several clinical parameters. The multielemental analysis of spermatozoa can be used to approximate quantities of trace elements inserted into the egg ooplasm at the time of fertilization. These elemental quantities appear to be in the femtogram (10?15) range. 相似文献
126.
Big Moose Basin: simulation of response to acidic deposition 总被引:2,自引:1,他引:1
George F. Davis John J. Whipple Steven A. Gherini Carl W. Chen Robert A. Goldstein Arland H. Johannes Peter W.H Chan Ronald K. Munson 《Biogeochemistry》1987,3(1-3):141-161
The ILWAS model has been enhanced for application to multiple-lake hydrologic basins. This version of the model has been applied to the Big Moose basin, which includes Big Moose Lake and its tributary streams, lakes, and watersheds. The basin, as defined, includes an area of 96 km2, with over 20 lakes and ponds, and 70 km of streams. Hydrologic and chemical calibrations have been made using data from seven sampling stations. When total atmospheric sulfur loading to the basin is halved, the model predicts, after four years of simulation, a decreasing sulfate concentration and to a lesser extent a rising alkalinity at Big Moose Lake outlet. At the end of four years, the results show an increase in pH of 0.1 to 0.5 pH units depending upon season. 相似文献
127.
Carroll D. Arnett Joanna S. Fowler Robert R. MacGregor David J. Schlyer Alfred P. Wolf Bengt Långström Christer Halldin 《Journal of neurochemistry》1987,49(2):522-527
The distribution of carbon-11-labeled L-deprenyl, an irreversible inhibitor of monoamine oxidase type B (MAO-B), was determined in the baboon brain by positron emission tomography. The irreversible blood-to-brain transfer constant (influx constant, Ki) was measured using a complete metabolite-corrected arterial plasma concentration curve. This influx constant was used as a measure of functional enzyme activity for sequential determinations of MAO-B recovery following a single high dose of unlabeled l -deprenyl. The half-life for turnover of MAO-B was thus determined to be 30 days. Using appropriate irreversible inhibitors, this procedure should be generally useful for determining enzyme turnover rates in any organ in vivo and can be applied to some human studies as well. 相似文献
128.
Amino Acid Sequences of Neuropeptides in the Sinus Gland of the Land Crab Cardisoma carnifex: A Novel Neuropeptide Proteolysis Site 总被引:1,自引:0,他引:1
Robert W. Newcomb 《Journal of neurochemistry》1987,49(2):574-583
The sinus gland is a major neurosecretory structure in Crustacea. Five peptides, labeled C, D, E, F, and I, isolated from the sinus gland of the land crab have been hypothesized to arise from the incomplete proteolysis at two internal sites on a single biosynthetic intermediate peptide "H", based on amino acid composition additivities and pulse-chase radiolabeling studies. The presence of only a single major precursor for the sinus gland peptides implies that peptide H may be synthesized on a common precursor with crustacean hyperglycemic hormone forms, "J" and "L," and a peptide, "K," similar to peptides with molt inhibiting activity. Here I report amino acid sequences of these peptides. The amino terminal sequence of the parent peptide, H, (and the homologous fragments) proved refractory to Edman degradation. Data from amino acid analysis and carboxypeptidase digestion of the naturally occurring fragments and of fragments produced by endopeptidase digestion were used together with Edman degradation to obtain the sequences. Amino acid analysis of fragments of the naturally occurring "overlap" peptides (those produced by internal cleavage at one site on H) was used to obtain the sequences across the cleavage sites. The amino acid sequence of the land crab peptide H is Arg-Ser-Ala-Asp-Gly-Phe-Gly-Arg-Met-Glu-Ser-Leu-Leu-Thr-Ser-Leu-Arg-Gly- Ser-Ala-Glu- Ser-Pro-Ala-Ala-Leu-Gly-Glu-Ala-Ser-Ala-Ala-His-Pro-Leu-Glu. In vivo cleavage at one site involves excision of arginine from the sequence Leu-Arg-Gly, whereas cleavage at the other site involves excision of serine from the sequence Glu-Ser-Leu. Proteolysis at the latter sequence has not been previously reported in intact secretory granules. The aspartate at position 4 is possibly covalently modified. 相似文献
129.
Molecular Forms of Acetylcholinesterase and Butyrylcholinesterase in Human Plasma and Cerebrospinal Fluid 总被引:1,自引:0,他引:1
John R. Atack Elaine K. Perry James R. Bonham Robert H. Perry 《Journal of neurochemistry》1987,48(6):1845-1850
The measurement of cholinesterase activities in either plasma or cerebrospinal fluid (CSF) may ultimately prove to be relevant in the diagnosis of neurological and neuropsychiatric disorders. However, studies to date have examined only total enzyme activities. Therefore in the present study we have examined the distribution of the individual molecular forms of both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in plasma and CSF using sucrose density gradient centrifugation. Although the total activities of AChE were of the same order of magnitude in plasma and CSF, there was a considerable difference (120-500-fold) between total BChE activity in the CSF and the BChE-rich plasma. The analysis of the individual molecular forms revealed that the predominant molecular species of AChE and BChE in the CSF--both lumbar and ventricular--was the G4 form. The G4 form also constituted the majority of the plasma BChE activity and, on average, over half (56%) of the plasma AChE activity. The significance of the AChE and BChE molecular form compositions of both plasma and CSF and their possible relationship to pathological states are discussed. 相似文献
130.
Initial (Fo), maximum (Fm) and steady-state (Fs) levels of modulated chlorophyll fluorescence were measured in intact avocado leaves (Persea americana Mill.) during state 1-state 2 transitions using a combination of modulated and non-modulated lights with synchronized detection. Under normal temperature conditions (20°C), transition from state 2 to state 1 was associated with a substantial increase (about 20%) in Fm and Fo whereas the Fm/Fo ratio remained constant, reflecting increased absorption cross-section of PS II. On the contrary, at moderately elevated temperature (35°C), these fluorescence changes were very limited, indicating marked inhibition of the state regulation. The fraction of light distributed to PS II () was calculated from the Fo, Fm and Fs levels for both types of leaves. In control leaves, varied from 48% (in state 2) to values as high as 58% (in state 1). In contrast, mild heat treatment resulted in values close to 50% in both states, indicating the inability of heated leaves to reach extreme state 1. The results suggested that avocado leaves under moderately elevated temperature conditions are blocked in a state close to state 2. This effect was shown to occur in a non-injurious temperature range (as shown by the preservation of the (photoacoustically monitored) oxygen evolution activity) and to be rapidly reversed upon lowering of the temperature. Thermally induced development of state 2 (independent on the light spectral quality) could possibly be a protective mechanism to avoid photodamage of the heat-labile PS II by high light intensities which usually accompany heat stress in the field. 相似文献