Forms over substance? -- A response to Viafora

Medicine, Health Care and Philosophy -     

Photodecomposition of DDA

The photodecomposition of aqueous solutions of 2,2-bis (p-chlorophenyl) acetic acid (DDA) was slow in sunlight and rapid in the laboratory, producingp,p-dichlorobenzophenone (DCB),p-chlorobenzaldehyde,P-chlorophenol, and several unidentified polar products.p,p-Di-chlorobenzilic acid, andp,p-dichlorobenzhydrol gave rise to the same photoproducts, while bis-(p-chlorophenyl) methane (DDM) and chlorobenzilate were converted only to DCB. DCB andp-chlorobenzaldehyde proved to be resistant to photodegradation but gradually producedP-chlorobenzoic acid which, in turn, formedp-hydroxybenzoic and benzoic acids, probably the last environmentally detectable links in the long chain of DDT degradation to CO₂ and water.High pressure liquid chromatography (HPLC) proved to be ideal for separating and quantitating the parent compounds and their photoproducts directly from the aqueous photolysates or from methanol solutions of the isolates and standards.Contribution to Regional Project W-45, Environmental Distribution, Transformation, and Toxicological Implications of Pesticide Residues. University of Arizona Agricultural Experiment Station journal series No. 2931.     

CAS information services for medicinal chemists

In summary, the medicinal chemist has four new ways to access the information contained in the CAS database: CAS ONLINE, the only structure search system based on the entire CAS Registry database, and three printed services, CA SELECTS, BIOSIS/CAS SELECTS, and CAS Customer-Defined Information Services, which provide abstracts on specialized topics of interest.     

Hypospadias trends in two US surveillance systems

OBJECTIVE: Hypospadias is a common congenital anomaly, the cause of which is unknown. Unexplained increases in the rates of hypospadias occurred in five European countries in the 1970s and 1980s. We examined data from two birth defects surveillance systems in the United States for evidence of similar trends. METHODOLOGY: The Metropolitan Atlanta Congenital Defects Program (MACDP) provided birth prevalence rates from 1968 to 1993. The nationwide Birth Defects Monitoring Program (BDMP) provided rates from 1970 to 1993. MACDP data are population-based and could be categorized by the severity of the hypospadias. BDMP data allowed analysis of rate trends for the four census regions of the United States. RESULTS: Data from both surveillance systems showed an approximate doubling of hypospadias rates in the 1970s and 1980s. MACDP data showed that the rate of severe cases increased while the ratio of mild to severe cases decreased. BDMP data showed that hypospadias rates increased markedly in all four regions of the United States. CONCLUSIONS: The observed increases are unlikely to be attributable to increased sensitivity of the surveillance systems or the identification of more mild cases by physicians over time, because either trend would have increased rather than decreased the ratio of mild to severe cases. If real, these trends represent the largest number of cases and the first report of an increase in hypospadias rates outside of Europe. Additional investigation of a possible increase in hypospadias rates is warranted.     

Immune responses against SARS-coronavirus nucleocapsid protein induced by DNA vaccine

The nucleocapsid （N） protein of SARS-coronavirus （SARS-CoV） is the key protein for the formation of the helical nucleocapsid during virion assembly. This protein is believed to be more conserved than other proteins of the virus, such as spike and membrane glycoprotein. In this study, the N protein of SARS-CoV was expressed in Escherichia coli DHSalpha and identified with pooled sera from patients in the convalescence phase of SARS. A plasmid pCI-N, encoding the full-length N gene of SARS-CoV, was constructed. Expression of the N protein was observed in COS1 cells following transfection with pCI-N. The immune responses induced by intramuscular immunization with pCI-N were evaluated in a murine model. Serum anti-N immunoglobutins and splenocytes proliferative responses against N protein were observed in immunized BALB/c mice. The major immunoglobulin G subclass recognizing N protein was immunoglobulin G2a, and stimulated splenocytes secreted high levels of gamma interferon and IL-2 in response to N protein. More importantly, the immunized mice produced strong delayed-type hypersensitivity （DTH） and CD^8＋ CTL responses to N protein.