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11.
The cholinergic agonist carbachol was injected into the pontine Pb area where PGO bursting cells have been recorded. When microinjections were localized to the ventrolateral aspect of the caudal Pb nucleus near aggregates of ChAT immunolabeled cholinergic neurons, carbachol produced an immediate onset of state-independent PGO waves in the ipsilateral LGB. These state-independent PGO waves persisted for 3-4 days. After the first 24 hrs PGO wave activity increasingly became associated with REM sleep and with REM transitional SP sleep as both of these PGO-related states increased in amount to 3-4 times baseline levels. The increase in amount of PGO-related states peaked on days 2-4 following one carbachol injection and persisted for 10-12 days. These results suggest a two stage process: stage one, PGO enhancement, is the direct consequence of the membrane activation of cholinoceptive PGO burst neurons by carbachol; stage two, REM enhancement, is the consequence of metabolic activation of endogenous cholinergic neurons. This experimental preparation is a useful model for the study of the electrophysiology and functional significance of PGO wave and REM sleep generation. 相似文献
12.
Jesper L. Aamand Audrey H. Hobson Catherine M. Buckley Steen T. Jørgensen Borge Diderichsen David J. McConnell 《Molecular & general genetics : MGG》1994,245(5):556-564
An extracellular Pseudomonas cepacia lipase, LipA, is inactive when expressed in the absence of the product of the limA gene. Evidence has been presented that LimA is a molecular chaperone. The lipA and limA genes have been cloned in separate and independently inducible expression systems in Escherichia coli. These systems were used to test the molecular chaperone hypothesis by investigating whether LimA could activate presynthesized prelipase and whether presynthesized LimA could activate newly synthesized prelipase. The results show that LimA cannot activate presynthesized prelipase and that presynthesized LimA can activate only a limited number of de novo synthesized prelipase molecules. Co-immunoprecipitation of prelipase/lipase with LimA generated a 1:1 complex of prelipase/lipase and LimA. The results suggest that a 1:1 complex of LipA and LimA is required for prelipase processing and secretion of active lipase. 相似文献
13.
Litman GW; Rast JP; Shamblott MJ; Haire RN; Hulst M; Roess W; Litman RT; Hinds- Frey KR; Zilch A; Amemiya CT 《Molecular biology and evolution》1993,10(1):60-72
Immunoglobulins are encoded by a large multigene system that undergoes
somatic rearrangement and additional genetic change during the development
of immunoglobulin-producing cells. Inducible antibody and antibody-like
responses are found in all vertebrates. However, immunoglobulin possessing
disulfide-bonded heavy and light chains and domain-type organization has
been described only in representatives of the jawed vertebrates. High
degrees of nucleotide and predicted amino acid sequence identity are
evident when the segmental elements that constitute the immunoglobulin gene
loci in phylogenetically divergent vertebrates are compared. However, the
organization of gene loci and the manner in which the independent elements
recombine (and diversify) vary markedly among different taxa. One striking
pattern of gene organization is the "cluster type" that appears to be
restricted to the chondrichthyes (cartilaginous fishes) and limits
segmental rearrangement to closely linked elements. This type of gene
organization is associated with both heavy- and light-chain gene loci. In
some cases, the clusters are "joined" or "partially joined" in the germ
line, in effect predetermining or partially predetermining, respectively,
the encoded specificities (the assumption being that these are expressed)
of the individual loci. By relating the sequences of transcribed gene
products to their respective germ-line genes, it is evident that, in some
cases, joined-type genes are expressed. This raises a question about the
existence and/or nature of allelic exclusion in these species. The
extensive variation in gene organization found throughout the vertebrate
species may relate directly to the role of intersegmental
(V<==>D<==>J) distances in the commitment of the individual
antibody-producing cell to a particular genetic specificity. Thus, the
evolution of this locus, perhaps more so than that of others, may reflect
the interrelationships between genetic organization and function.
相似文献
14.
The possibility thatChlamydia trachomatis contains peptidoglycan was examined by three methods. Preincubation of chlamydia with enzymes known to cleave peptidoglycan had no adverse effect on the subsequent development. Immunofluorescence studies with antistreptococcal peptidoglycan antisera failed to show any cross reactions with chlamydial antigens. The antichlamydial activity of anti-cell-wall antimicrobials was examined; lactams proved the most active, and cycloserine and bacitracin also showed antichlamydial activity. Alaphosphin, phosphomycin, and vancomycin showed no antichlamydial activity at the concentrations tested. 相似文献
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19.
G. E. Hobson 《The Biochemical journal》1964,92(2):324-332
20.
Jason D. Roh Nicholas Houstis Andy Yu Bliss Chang Ashish Yeri Haobo Li Ryan Hobson Carolin Lerchenmüller Ana Vujic Vinita Chaudhari Federico Damilano Colin Platt Daniel Zlotoff Richard T. Lee Ravi Shah Michael Jerosch‐Herold Anthony Rosenzweig 《Aging cell》2020,19(6)
Heart failure with preserved ejection fraction (HFpEF) is the most common type of HF in older adults. Although no pharmacological therapy has yet improved survival in HFpEF, exercise training (ExT) has emerged as the most effective intervention to improving functional outcomes in this age‐related disease. The molecular mechanisms by which ExT induces its beneficial effects in HFpEF, however, remain largely unknown. Given the strong association between aging and HFpEF, we hypothesized that ExT might reverse cardiac aging phenotypes that contribute to HFpEF pathophysiology and additionally provide a platform for novel mechanistic and therapeutic discovery. Here, we show that aged (24–30 months) C57BL/6 male mice recapitulate many of the hallmark features of HFpEF, including preserved left ventricular ejection fraction, subclinical systolic dysfunction, diastolic dysfunction, impaired cardiac reserves, exercise intolerance, and pathologic cardiac hypertrophy. Similar to older humans, ExT in old mice improved exercise capacity, diastolic function, and contractile reserves, while reducing pulmonary congestion. Interestingly, RNAseq of explanted hearts showed that ExT did not significantly modulate biological pathways targeted by conventional HF medications. However, it reversed multiple age‐related pathways, including the global downregulation of cell cycle pathways seen in aged hearts, which was associated with increased capillary density, but no effects on cardiac mass or fibrosis. Taken together, these data demonstrate that the aged C57BL/6 male mouse is a valuable model for studying the role of aging biology in HFpEF pathophysiology, and provide a molecular framework for how ExT potentially reverses cardiac aging phenotypes in HFpEF. 相似文献