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21.
A. C. Steere R. L. Grodzicki J. E. Craft M. Shrestha A. N. Kornblatt S. E. Malawista 《The Yale journal of biology and medicine》1984,57(4):557-560
Since the summer of 1982, we have cultured patient specimens for Lyme disease spirochetes. Of 118 patients cultured, four specimens yielded spirochetes: two from blood, one from a skin biopsy specimen of erythema chronicum migrans (ECM), and one from cerebrospinal fluid. All four isolates appeared identical when examined with a monoclonal antibody. However, attempts to recover the spirochete from synovium or synovial fluid were unsuccessful. In addition, the organism could not be visualized in skin or synovial biopsy specimens using the avidin-biotin peroxidase complex detection system. Thus, the current yield in culturing spirochetes from patients is quite low, and it is not yet known whether the organism is still alive later in the disease when arthritis is present. 相似文献
22.
L. R. Guy Valadon Mohamed Osman Rosemary S. Mummery Simone Jerebzoff-Quintin S. Jerebzoff 《Physiologia plantarum》1982,56(2):199-203
An action spectrum for carotenogenesis in V. agaricinum has maxima at 395, 433, 660 and 737 nm. In a previous study it had been shown that a light-minus-dark difference spectrum of a crude extract from V. agaricinum had maxima at 390 and 420 nm, and furthermore a red, far-red interaction suggesting phytochrome involvement has been proposed. All these data suggest that there may be at least two photoreceptor systems operating in the photoinduction process here; one for the near-ultraviolet (UV-A)-mediated carotenogenesis, presumably a novel pigment, and the other for the red, far-red region, most likely phytochrome. 相似文献
23.
Paul F. Hamlyn Rosemary E. Bradshaw Fiona M. Mellon Claro M. Santiago Jane M. Wilson John F. Peberdy 《Enzyme and microbial technology》1981,3(4):321-325
Several commercial polysaccharases have been compared for their ability to liberate protoplasts from fungi. These enzymes were found to contain side activities capable of hydrolysing fungal cell walls. Protoplasts have been commonly isolated from fungi using enzyme systems prepared by workers in their own laboratories. However, these procedures are time consuming and considerable variation may be found between different batches of enzyme. The present study shows that high yields of protoplasts can be prepared from a variety of fungi using relatively cheap commercial enzymes. The yields obtained were normally as good as or better than those previously produced. 相似文献
24.
Henry Taylor Jane Teas Thomas Richie Charles Southwick Ram Shrestha 《Primates; journal of primatology》1978,19(2):343-351
In 1,506 hours of field observations on free-ranging rhesus monkeys in Kathmandu Valley, Nepal, in 1974 and 1975 18 cases
of favorable social interactions between adult males and infants were observed. Eleven of these were brief encounters of play
or grooming; seven were more extended cases of male care. One of the latter was a complete adoption of a neonatal orphan by
a dominant male. This adoption was possessive and restrictive and it resulted in the death of the infant by starvation within
three days. A similar adoption involving the same male occurred in 1976 and it also resulted in the death of the infant. Most
of the favorable male-infant interactions occurred during the winter and spring when the infants were 6 to 12 months of age.
These favorable social interactions involved eight males in six different troops, out of a total of about 48 males in 12 troops
in our study population of approximately 600 monkeys. These observations are discussed in light of current sociobiological
theories. 相似文献
25.
Cystine accumulation in cystinotic fibroblasts from free and protein-linked cystine but not cysteine 总被引:5,自引:2,他引:3 下载免费PDF全文
The accumulation of cystine in cystinotic fibroblasts from free and protein-linked cystine has been investigated. Cystine is not accumulated from cysteine but is readily accumulated from cystine. The accumulation from free cystine does not occur as a result of pinocytosis or from the degradation of a rapidly metabolized protein pool. Further studies of the degradation of disulphide-containing proteins by these cells may aid understanding of the mechanisms of proteolysis. 相似文献
26.
Dictyostelium discoideum (Dd) 1-H vegetative amoebae exposed to cAMP differentiate into mature stalk cells within 48 h [6]. It was of interest to monitor the patterns of glycoprotein synthesis in the amoebae during the first 5 h of exposure to cAMP and phosphate buffer (PB) controls. Following the exposure period the amoebae were labeled with
-[6-3H]fucose. It was determined by both silver grain counts of autoradiographs and scintillation spectroscopy that within minutes cAMP effects an inhibition of [3H]fucose incorporation. However, by 5 h of exposure both experimentals and controls lose a major amount of their labeling capacity based upon the initial PB control value. Vegetative amoebae exposed to cAMP mimics the sparse labeling found in prestalk cells. Prestalk cells synthesize cellulose as a result of cAMP-induced gluconeogenesis and consequently glycoprotein synthesis is reduced. Cellular interactions promoted by cAMP appears to initiate prestalk cell differentiation during the pre-aggregation phase of development. This event is accompanied by a loss in the ability of the aggregating cells to synthesize glycoprotein. 相似文献
27.
The cephalic, middle and posterior regions of the testes in Garra gotyla are identical in structure and function. The spermatogenetic activity starts in the month of October reaching its peak in April and May. Spawning takes place in June and July followed by a brief resting period. Spermiation appears to be intermittent. Six stages of spermatogenesis have been described. New crop of germ cells appears to arise from the resting spermatogonia. Both the interstitial and the lobule boundary cells were observed. The gonosomatic index shows correlatation between the rise in water temperature and the volume of the testes. 相似文献
28.
Histology and annual cyclic changes in the testicular activity of S. plagiostomus have been described. The reproductive cycle has been divided into eight phases. The weight and volume of the testes and GSI show correlation with each other, and increase twice in a year (September and March), indicating the existence of two spawning periods. A distinct dormant period during winter intervenes the spawning peaks. Although the testes contain mature spermatozoa during winter, spermiation remains halted until last week of February. On the return of favourable environmental conditions in March, spermiation begins again and complete depletion takes place. 相似文献
29.
30.
Synopsis A quantitative analysis has been made of the glycoproteins present in the goblet cells of the epidermis, gill filaments and gill lamellae of three species of teleost fish. The glycoproteins have been identified by a combination of techniques, including the use of the enzyme sialidase followed by Alcian Blue staining, at pH 2.6 or I. o, in combination with periodic acid-Schiff. The selected fish were representative of species living in marine, freshwater and estuarine environments.The range of glycoproteins identified in these fish was similar to that found in mammalian tissue in that both neutral and acid glycoproteins were present, the latter included both sialomucins sensitive and resistant to sialidase, and sulphomucin. A single goblet cell contained either neutral or acid glycoproteins alone or in combination. Only the epidermis of the plaice and rainbow trout contained uniform cell populations producing acid glycoproteins, the former sulphomucin and the latter mainly sialomucin. At each site in the flounder and in the gill epithelia of the plaice and rainbow trout, the goblet cell population was mixed, with cells producing each type of glycoprotein. The number of goblet cells producing each type of glycoprotein varied at each tissue site. 相似文献