ORGANIC INTERMEDIATES FROM SWITZERLAND tor dyestuffs pharmaceuticals agrochemicals perfumes photochemicals
0"
: (CH3)3
2-tert. Butylcyclohexanol 2-tert. Butylcyclohexanol 4-Amino-1 -benzylpiperidine 4-Amino-1 -benzylpiperidine
NH 2
2,4,6-Trimethylaniline Mesidine
groups was to use affinity chromatography procedures in which enzyme substrates—such as the bacterial substance pepstatin—were used to bind the proteolytic enzymes that normally would destroy the renin. Finally, purity of the enzyme, with a molecular weight of about 40,000, was established with polyacrylamide disk gel electrophoresis. "Complete purification now will enable researchers to devise a method for measuring renin directly in the blood of patients with hypertension," Slater says. Until now, doctors have been able to measure renin only indirectly, as one of its precursors, with a radioimmunoassay. Moreover, the pure enzyme now can be subjected to biochemical tests that will enable scientists to develop drugs capable of completely inhibiting renin activity. Next step for the Boston and Nashville groups is to purify enough renin to be used in further biological testing and for determining its amino acid sequence. Also involved in the Massachusetts General Hospital phase of the renin purification were Dr. Victor Dzau and Robert Cohn. At Vanderbilt, the research was carried out by Dr. Hideyoshi Yokosawa, Dr. Tadashi Inagami, and Dr. Erwin Haas. •
CH 3
2,4,6-Trimethylaniline Mesidine NO. COOH
J&
(NH2) COOH
5-Nitroisophthalic acid 5-Aminoisophthalic acid NH2
4c, a,a,a -Trifluoro-m-toluidine,99% 3-Aminobenzotrifluoride COOH
ci
4-Chlorobenzoic acid Isosorbide dinitrate, ISDN mixtures with lactose, etc. For catalog,samples.technical data pleasecontact: US-Agents: Riches-Nelson, Inc., 254 Mill Street, Greenwich, Conn. 06830 Phone: 203-869-3088 Samples for commercial trade only Agents in other countries: Please inquire
SSF DOTTIKON Swiss Explosives Works Ltd. CH-5605 Dottikon/Switzerland Phone 057/4 05 55 • Telex 52 694 fasex ch
Use of nuclear pacemakers declining
laLV'L'ki Poly thiols Polymercaptans -R-(SH)n Dimercapto diethyl ether 0(CH2CH2-SH)2 Dithiolterephthalic Acid 0 0 HS—C-
_C—SH
Glycol Dimercaptoacetate HS—CH2C00CH2 HS—CHJCOOCHJ
Even though they still are doing a good job in patients with erratic heartbeats, nuclear pacemakers seem to be on the way out. So said Dr. Victor Parsonnet of Beth Israel Medical Center in Newark, N.J., at the Dallas meeting of the American Heart Association. In the past five years, only about 5000 nuclear pacemakers (containing plutonium-238) have been installed worldwide, while in the U.S. alone about 300,000 Americans are wearing pacemakers, predominantly of the nonnuclear lithiumpowered type, Parsonnet says. The decline in use of the once popular plutonium pacemakers, he proposes, stems from their high cost (from $7000 to $8000, compared to $1800 to $2500 for the lithium pacemakers), original licensing restrictions, and unfounded concerns about radioactive hazards involving the patient and the public at large. Older patients with irregular heartbeat patterns now are usually fitted with the lithium devices, which have a life span of as much as 15 years, Parsonnet says. On the other hand, younger heart patients probably will continue to be fitted with the nuclear pacemakers, with their expected life span of 30 to 40 years, he predicts. In spite of the general decline in use, Parsonnet says that his own studies of 117 patients who received the plutonium pacemakers at Beth Israel showed that the devices perform very well. Only 20 patients required a second implant because of electrical or mechanical defects. No unit has yet failed, he notes. •
Glycol Dimercaptopropionate [Ethylene bis (b-mercaptopropionate) HS—CH2CH2C00CH2 HS—CH2CH2C00CH2 Pentaerythritol Tetra (3-Mercaptopropionate) C(CH 2 00CCH 2 CH 2 -SH) 4 Pentaerythritol Tetrathioglycolate C(CH200CCH2—SH)4 Trimethylolethane Tri (3-Mercaptopropionate) CH3C(CH200CCH2CH2—SH)3 Trimethylolethane Trithioglycolate CH3C(CH200CCH2—SH)3 Trimethylolpropane Tri (3-Mercaptopropionate) CH3CH2C(CH200CCH2CH2-SH)3 Trimethylolpropane Trithioglycolate CH3CH2C(CH200CCH2—SH)3 Of interest as: 1. Curing or cross-linking agents for polymeric systems, especially epoxy resins. 2. Intermediates for stabilizers. 3. Intermediates for anti-oxidants. 4. Chain transfer or polymerization modifier. SAMPLES AVAILABLE ON REQUEST
C H e m e n c s , irvc. 90 Tokeneke Road, Darien, CT. 06820 Phone: 203-655-8741 Cable: EVANSCHEM / TWX: 710-457-3356
Dec. 4, 1978C&EN
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