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21.
A 5-month-old male infant presented with weak cry, decreased body movements, tightness of whole body since birth, and one episode of generalized seizure on day 4 of life. He was born at term by elective caesarian section performed for breech presentation. The child had failure to thrive, contractures at elbow and knee joints, hypertonia, microcephaly, small mouth, retrognathia, and camptodactyly. There was global developmental delay. Abdominal examination revealed umbilical and bilateral inguinal hernia. Visual evoked response and brainstem evoked response audiometry were abnormal. Nerve conduction velocity was normal. Magnetic resonance imaging of brain revealed paucity of white matter in bilateral cerebral hemispheres with cerebellar and brain stem atrophy. The differential diagnoses considered in the index patient were distal arthrogryposis (DA) syndrome, cerebroculofacioskeletal syndrome, and Pena Shokier syndrome. The index patient most likely represents a variant of DA: Sheldon Hall syndrome. 相似文献
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Role of amino acids, betaine and choline in vitamin B12 biosynthesis by strains of Propionibacterium
This paper reports the role of amino acids, betaine and choline on vitamin B12 biosynthesis in Propionibacterium shermanii 566, P. shermanii and Propionibacterium arl AKU 1251. l-Glutamic acid supplemented at the 0.05% (w/v) level in whey permeate stimulated vitamin B12 production in the three organisms, whereas the influence of other amino acids differed in the three strains. A uniform increase in product formation in Propionibacterium cultures with increasing doses of betaine and choline was recorded, but with variable relative effectiveness. However, no significant difference at the 0.50 and 0.75% (w/v) levels of these two compounds was observed. The addition of betaine at 0.5% (w/v) concentration was considered optimal for maximum fermentation efficiency in the cultures. An increase of 2.8–25.7% and 5.1–40.8% in vitamin B12 yield as compared to the control was observed by supplementing whey permeate medium with l-glutamic acid and betaine, respectively, at their optimum values in the organisms studied. 相似文献
24.
C.S. Gohlwar R.P. Sethi S.S. Marwaha V.K. Seghal J.F. Kennedy 《Enzyme and microbial technology》1984,6(7):312-316
This article examines the potential of lactose from whey permeate as a substrate for gibberellic acid production. In addition, the paper reports the derivation of mathematical models which simulate the various fermentation conditions to predict precise values. Of the five Fusarium moniliforme isolates screened for their ability to synthesize the gibberellic acid, F. moniliforme-1 proved to be the best strain (670 mg gibberellic acid/l) when fermentation was carried out at 28°C for 12 days. The product started to accumulate at the end of maximum growth phase (day 9) and continued until the curve reached a plateau (day 12). From the observed data and expected values, a temperature range of 27–30°C, pH range of 3.5–5.5 and an inoculum level of 10–12.5% (v/v) were considered optimal for attaining the highest product yield. However, nitrogen sources supplemented in whey permeate medium suppressed the ability of the culture under study to synthesize metabolite and utilize lactose. 相似文献
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Robson Sartorello Alexandre Budu Piero Bagnaresi Carlos AH Fernandes Paloma M. Sato Vânia B. Bueno Marcos RM Fontes Pedro L. Oliveira Gabriela O. Paiva‐Silva Simone V. Alves Luis ES Netto Luiz H. Catalani Celia RS Garcia 《Cell biology international》2010,34(8):859-865
The cellular traffic of haem during the development of the human malaria parasite Plasmodium falciparum, through the stages R (ring), T (trophozoite) and S (schizonts), was investigated within RBC (red blood cells). When Plasmodium cultures were incubated with a fluorescent haem analogue, ZnPPIX (Zn protoporphyrin IX) the probe was seen at the cytoplasm (R stage), and the vesicle‐like structure distribution pattern was more evident at T and S stages. The temporal sequence of ZnPPIX uptake byP. falciparum‐infected erythrocytes shows that at R and S stages, a time‐increase acquisition of the porphyrin reaches the maximum fluorescence distribution after 60 min; in contrast, at the T stage, the maximum occurs after 120 min of ZnPPIX uptake. The difference in time‐increase acquisition of the porphyrin is in agreement with a maximum activity of haem uptake at the T stage. To gain insights into haem metabolism, recombinant PfHO (P. falciparum haem oxygenase) was expressed, and the conversion of haem into BV (biliverdin) was detected. These findings point out that, in addition to haemozoin formation, the malaria parasite P. falciparum has evolved two distinct mechanisms for dealing with haem toxicity, namely, the uptake of haem into a cellular compartment where haemozoin is formed and HO activity. However, the low Plasmodium HO activity detected reveals that the enzyme appears to be a very inefficient way to scavenge the haem compared with the Plasmodium ability to uptake the haem analogue ZnPPIX and delivering it to the food vacuole. 相似文献
27.
P. MARTIN SANDER F.L.S. MICHAEL B. LEITE THOMAS MÖRS WINFRIED SANTEL WIGHART von KOENIGSWALD 《Zoological Journal of the Linnean Society》1994,110(2):141-179
Morphology and schmelzmuster of rootless cheek teeth of 25 extant rodent genera were studied in relation to jaw movement. A differentiation between leading and trailing edges is observed regularly in enamel thickness and schmelzmuster. Similarities between antagonists are interpreted as 'functional symmetries'. Differences in the enamel thickness, the schmelzmuster and orientation of cutting edges are controlled by functional and phylogenetic constraints. The heterogenous sample allows discrimination between these two constraints. The most obvious functional constraint leads to the almost regular occurrence of radial enamel on the push sides of cutting edges. The degree of functional symmetry seems to be determined by phylogenetic limitations. 相似文献
28.
The effects of nitrogen source NO3− or NH4+ on nitrogen metabolism during the first 2 weeks of germination of the rice seedling (Oryza sativa L., var. IR22) grown in nutrient solution containing 40 μg/ml N were studied. Total, soluble protein, and free amino N levels were higher in the NH4+-grown seedling, particularly during the 1st week of germination. Asparagine accounted for most of the difference in free amino acid level, in both the root and the shoot. Nitrate and nitrite reductase activities were present mainly in the shoot and were higher in the NO3−-grown seedling, whereas the activity of glutamate dehydrogenase and glutamine synthetase in the root tended to be lower than that of the NH4+-grown seedling during the 1st week of germination. Glycolate oxidase and catalase activities were present mainly in the shoot. Maximum activity of the above five enzymes occurred 7 to 10 days after germination. Differences in the zymograms of nitrate reductase, glutamate dehydrogenase, and catalase were mainly between shoot and root and not from N source. Nitrite reductase bands were observed only in plants grown in plants grown in NO3−. 相似文献
29.
Block of outward current in cardiac purkinje fibers by injection of quaternary ammonium ions 总被引:6,自引:5,他引:1
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We have studied the effects of iontophoretic injection of the quaternary ammonium compounds tetraethylammonium (TEA) and tetrabutylammonium (TBA) in cardiac purkinje fibers. We find that TBA(+) is a more effective blocker than TEA(+), but injection of either compound reduces the time-dependent outward plateau currents, transient outward current (I(to)), and the delayed rectifier (I(x)). Our findings provide evidence that these outward cardiac currents are carried by channels that in some respects are pharmacologically similar to squid axon potassium channels. We demonstrate that this procedure is a new tool that can be useful in the analysis of membrane currents in the heart. 相似文献
30.
IB Masters MM Eastburn PW Francis R Wootton PV Zimmerman RS Ware AB Chang 《Respiratory research》2005,6(1):16