Punctuated equilibrium and the fossil record     

Schopf TJ  Hoffman A 《Science (New York, N.Y.)》1983,219(4584):439-440

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Naturally acquired antibodies to sporozoites do not prevent malaria: vaccine development implications   总被引：12，自引：0，他引：12  

S L Hoffman  C N Oster  C V Plowe  G R Woollett  J C Beier  J D Chulay  R A Wirtz  M R Hollingdale  M Mugambi 《Science (New York, N.Y.)》1987,237(4815):639-642

The first human vaccines against the malaria parasite have been designed to elicit antibodies to the circumsporozoite protein of Plasmodium falciparum. However, it is not known whether any level of naturally acquired antibodies to the circumsporozoite protein can predict resistance to Plasmodium falciparum malaria. In this study, 83 adults in a malaria-endemic region of Kenya were tested for circumsporozoite antibodies and then treated for malaria. They were monitored for the development of new malaria infections for 98 days. Antibody levels, as determined by four assays in vitro, were indistinguishable between the 60 individuals who did and the 23 who did not develop parasitemia during follow-up, and there was no apparent relation between day of onset of parasitemia and level of antibodies to circumsporozoite protein. Unless immunization with sporozoite vaccines induces antibodies that are quantitatively or qualitatively superior to the circumsporozoite antibodies in these adults, it is unlikely that such antibodies will prevent infection in areas with as intense malaria transmission as western Kenya.  相似文献   

Uronic Acid of Chondroitin Sulfate B     

Hoffman P  Linker A  Meyer K 《Science (New York, N.Y.)》1956,124(3234):1252-1253

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Genetic restriction of energy conservation in Schizophyllum   总被引：2，自引：0，他引：2  

R M Hoffman  J R Raper 《Science (New York, N.Y.)》1971,171(969):418-419

A genetically determined malfunction of energy conservation reduces assimilation of substrate to half or less its normal level while leaving oxidative processes apparently unchanged. This metabolic defect, which differs in many ways from any previously described, is related to the function of the B incompatibility factor and occurs both in the common A heterokaryon (A = B not equal)-in which two compatible, wild B factors interact-and in mutant-B homokaryons.  相似文献   

Campus demonstrations     

Hoffman LG 《Science (New York, N.Y.)》1968,161(3836):8

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Infectious disease. Research (genomics) is crucial to attacking malaria     

Hoffman SL 《Science (New York, N.Y.)》2000,290(5496):1509

Solving the enormous problem of malaria worldwide will require a balance between investments in research and control. In this point-counterpoint, two scientists describe the rationales for these very different strategies. Steve Hoffman believes that genomics research is the best investment in the future if we have the vision of malaria eradication. Chris Curtis presents an opposing viewpoint, that low-tech control approaches are the practical ones under current conditions.  相似文献   

Visual recognition     

Hoffman JE 《Science (New York, N.Y.)》1994,263(5154):1780-1781

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Hyperkalemic periodic paralysis and the adult muscle sodium channel alpha-subunit gene   总被引：22，自引：0，他引：22  

B Fontaine  T S Khurana  E P Hoffman  G A Bruns  J L Haines  J A Trofatter  M P Hanson  J Rich  H McFarlane  D M Yasek 《Science (New York, N.Y.)》1990,250(4983):1000-1002

Hyperkalemic periodic paralysis (HYPP) is an autosomal dominant disorder characterized by episodes of muscle weakness due to depolarization of the muscle cell membrane associated with elevated serum potassium. Electrophysiological studies have implicated the adult muscle sodium channel. Here, portions of the adult muscle sodium channel alpha-subunit gene were cloned and mapped near the human growth hormone locus (GH1) on chromosome 17. In a large pedigree displaying HYPP with myotonia, these two loci showed tight linkage to the genetic defect with no recombinants detected. Thus, it is likely that the sodium channel alpha-subunit gene contains the HYPP mutation.  相似文献   

The fall, recovery, orbit, and composition of the Tagish Lake meteorite: a new type of carbonaceous chondrite     

Brown PG  Hildebrand AR  Zolensky ME  Grady M  Clayton RN  Mayeda TK  Tagliaferri E  Spalding R  MacRae ND  Hoffman EL  Mittlefehldt DW  Wacker JF  Bird JA  Campbell MD  Carpenter R  Gingerich H  Glatiotis M  Greiner E  Mazur MJ  McCausland PJ  Plotkin H  Rubak Mazur T 《Science (New York, N.Y.)》2000,290(5490):320-325

The preatmospheric mass of the Tagish Lake meteoroid was about 200,000 kilograms. Its calculated orbit indicates affinity to the Apollo asteroids with a semimajor axis in the middle of the asteroid belt, consistent with a linkage to low-albedo C, D, and P type asteroids. The mineralogy, oxygen isotope, and bulk chemical composition of recovered samples of the Tagish Lake meteorite are intermediate between CM and CI meteorites. These data suggest that the Tagish Lake meteorite may be one of the most primitive solar system materials yet studied.  相似文献   

Effects of aerosolized albuterol on physiologic responses to exercise in standardbreds.     

M R Mazan  A M Hoffman 《American journal of veterinary research》2001,62(11):1812-1817

OBJECTIVE: To examine the effects of an aerosolized beta2-adrenoreceptor agonist, albuterol, on performance during a standardized incremental exercise test in clinically normal horses. ANIMALS: 8 Standardbred pacing mares. PROCEDURE: Clinically normal horses, as judged by use of physical examination, hematologic findings, serum biochemical analysis, and airway endoscopy, were randomly assigned to 2 groups and were given 900 microg of albuterol via a metered-dose inhaler 30 minutes before beginning a standardized incremental exercise test in a crossover design with a 7-day minimum washout. Further examination included measurement of baseline lung mechanics, response to histamine bronchoprovocation, and bronchoalveolar lavage. RESULTS: No significant differences (albuterol vs placebo) were seen for any incremental exercise test variables (ie, maximum oxygen consumption, maximum carbon dioxide consumption, respiratory quotient, treadmill speed at heart rate of 200 beats/min, or number of steps completed during an incremental exercise protocol). Mast cell percentage was significantly (r = -0.84) associated with the concentration of aerosolized histamine that evoked a 100% increase in total respiratory system resistance. No other direct correlations between bronchoalveolar lavage fluid cell types and any indices of exercise capacity or airway reactivity were found. CONCLUSIONS AND CLINICAL RELEVANCE: Although no horse had exercise intolerance, 4 horses had airway hyperreactivity with bronchoalveolar lavage fluid mastocytosis; these horses may have been subclinically affected with inflammatory airway disease. In our study, albuterol did not enhance performance in 8 clinically normal racing-fit Standardbreds.  相似文献