1008 



Koff, Raymond S., George F. Grady, Thomas C. Chalmers, James W. Mosley, Betsy 

 Lee Swartz , and the Boston Inter-Hospital Liver Group. 1967. 



Viral hepatitis in a group of Boston hospitals. III. Importance of exposure 

 to shellfish in a nonepidemic period. New England J. Med. 276(13): 703-710. 



During a period of declining incidence of hepatitis, 270 adult patients with 

 viral hepatitis and an equal number of matched control patients were inter- 

 viewed. The 70 patients with hepatitis after transfusion and 15 who admitted 

 narcotic addiction had no other potential exposures more frequently than their 

 controls. The remaining 185 patients had often been exposed to jaundiced 

 persons or patients known to have hepatitis, compared to controls, but a 

 number of less obvious potential exposures occurred so frequently in patients 

 with hepatitis, compared to controls, that these were thought to be 

 significant sources of nonepidemic hepatitis. These included contact with 

 acutely ill but not jaundiced young children, ingestion of raw clams and 

 oysters, out-of-state travel, and tissue penetrations by physicians. 

 Ingestion of steamed clams was also significantly more common in the hepatitis 

 group, suggesting a causal relation between ingestion of cooked shellfish and 

 hepatitis. Ingestion of raw shellfish and steamed clams seemed to be as 

 common a source of infection as contact with jaundiced persons. Raw shellfish 

 consumption was reported by 34 patients with hepatitis, and only by 10 

 controls, among 185 of each group; raw clams were reported by 25 patients, 

 only 8 controls; raw oysters by 12 patients, only 3 controls; steamed clams by 

 13 patients, only 2 controls. Results were statistically significant at 

 P=0.05 or better. Eating of fried clams was reported by 24 hepatitis patients 

 and 30 controls; the difference was not statistically significant. This last 

 result was explained by the fact that fried clams are often Spisula, which 

 comes from offshore waters, less polluted, and that in addition such clams 

 may be sterilized by cooking. Steamed clams are usually My a, and it is 

 common to consider them done when valves gape, which does not necessarily 

 allow time for sterilization. Clams eaten raw are usually Mercenaria 

 mercenaria. - J.L.M. 



1009 



Kohn, Alan J. 1964. 



Mollusks. Science 145: 518-519. 



At the symposium on Mollusca held at the Zoological Society of London, 

 4-5 March. 1964, A. Ansell described seasonal biochemical changes in Venus 

 meraenaria and noted that successful reproduction in British waters occurred 

 only at Southampton. Suitable water temperatures for spawning, above 18 °C, 

 occur at Southampton. The seawater is warmed by industrial cooling systems. 

 - W.J.B. 



1010 



Kominz, D. R. , F. Saad, and K. Laki. 1957. 



Vertebrate and invertebrate tropomyosins. Nature 179(4552): 206-207. 



Tropomyosins, proteins found widely in vertebrate and invertebrate muscles, 

 all have sedimentation constants falling along the same line and extrapolating 

 to an S 2 g,w(c=0) of about 3.0. Lysine-arginine distribution and total anionic 

 charge of a given tropomyosin can be correlated with the phylum to which the 

 animal belongs. An apparent exception to these regularities was found when 

 squid tropomyosin was compared with tropomyosin found to be abundant in 

 smooth-muscle adductor of Venus. The clam had a low net charge and inversion 

 of its lysine and arginine values. Ammonium sulphate fractionation of clam 

 tropomyosin yielded a main fraction (about 80%) precipitating between 28 and 

 40% saturation, called tropomyosin A, and a second fraction precipitating 

 between 45 and 65% saturation, called tropomyosin B. Tropomyosin B had the 

 same lysine and arginine values as squid tropomyosin, and approximately the 

 same charge. This apparently was the first time that 2 tropomyosins had been 

 isolated from a single muscle. Abundance of tropomyosin A, and the small 

 amount of myosin that can be isolated from clam muscle, suggest that 

 tropomyosin A is part of the contractile system in clam adductor muscle. 

 Detailed accounts were to be published later. - J.L.M. 



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