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2 methods are described for the preparation of an oxygen functionalized vinylcopper reagent. Reactions of this reagent with cyclic and acyclic enones give products of 1,4 addition. The labile methoxyisopropyl group was used as an alcohol protecting group for ease of formation and removal. The influence of reaction conditions such as solvents and temperature on the mode of addition and yield is discussed. (S)-1-Iodo-trans-1-octen-3-ol (16a) was prepared from (S)-1-octyn-3-ol (17). The optically pure iodovinylcarbinol was converted to the cuprate 2 and 1,4 addition to the hydroxy-protected cyclopentenone 14c afforded (-)-PGE1 (18b).

The suppressive action of corticosteroids in man was determined by analysing the difference in the integrals of diurnal variation of serum Cortisol from control persons and from patients receiving a single dose of fluocortolone or prednisolone. Linear log dose response curves were obtained.

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In 5 patients with implanted cardiac pacemakers, an extra “heart sound” or pacemaker sound could be heard and recorded over the precordium. This sound, which occurred with each pacemaker impulse, had a clicking or snapping quality and was louder during expiration. Phonocardiograms and high speed oscillograms showed the latency of the pacemaker sound to be 3.5 msec after the pacemaker impulse. The pacemaker sound was also present in 1 patient with intermittent normal sinus rhythm; each pacemaker impulse was followed by the extra sound, even when some of the impulses fell in the absolute refractory period of the patient's own cardiac cycle. It is concluded that intercostal muscle contractions cause the extra sound.

Summary The arrhythmogenic effects of mechanical stimulation of isolated heart were investigated in the absence and presence of acetylstrophanthidin (AS). Brief mechanical shocks were applied to the anterior ventricular surface of Langendorff perfused rabbit hearts at known times in the cardiac cycle. Single premature ventricular contractions were consistently produced except when the mechanical stimuli were applied in the refractory period. In the absence of AS a refractory period was seen, but vulnerability to mechanical stimuli was not observed. During perfusion with AS (0.5 mg/L), mechanical stimuli applied in a vulnerable period induced countershock-reversible ventricular fibrillation in ten of fifteen hearts at a total mean AS dose of 0.4 mg. The other five hearts displayed major ventricular arrhythmias at a comparable AS dose. Control hearts, without mechanical stimuli, developed irreversible ventricular fibrillation at a total mean AS dose of 2.8 mg. Periods of refractoriness and vulnerability to mechanical stimuli were comparable to those for electrical stimuli, both in the absence and presence of AS. Some factors influencing mechanical stimulation are considered and some suggestions are advanced concerning avoidance of mechanically induced arrhythmias in humans.

The defensive secretion of the “daddy longlegs” Leiobunum vittatum was analyzed and found to contain the acyclic ketones 4-methylheptan-3-one and E-4,6-dimethyl-6-octen-3-one as its major organic components. Although 4-methylheptan-3-one has been found previously as an alarm substance in certain ant genera, the second component, whose structure is confirmed by synthesis, is new.

Normale ACTH-Spiegel liegen nach den Untersuchungen einer Reihe von Autoren zwischen 3 und 6 μE/ml Plasma. Wollte man ein rein chemisches Bestimmungsverfahren fur ACTH-Spiegel im Plasma entwickeln, so muste man in der Lage sein, 3–6 mal 10-11 g ACTH-Peptid aus 1 ml Plasma zu isolieren und nachzuweisen. Es sieht zur Zeit nicht so aus, als ob es gelingen konnte, diese analytische Aufgabe zu bewaltigen. Die Struktur der im Blut zirkulierenden ACTH-Aktivitat ist namlich obendrein noch nicht gesichert. Ob das ACTH im Blut ebenso wie das aus der Hypophyse extrahierte ACTH aus 39 Aminosauren besteht, ist insofern fraglich, als bekanntlich schon erheblich kurzere Peptide die volle biologische Wirkung zeigen. Zur Erfassung von ACTH-Spiegeln im Plasma sind wir daher noch immer auf biologische Bestimmungsmethoden angewiesen.

The spatial distribution of negatively charged Zn dopant atoms in GaAs has been investigated by cross-sectional scanning tunneling microscopy. At high densities, the dopant atoms exhibit clear clustering behavior, suggesting the existence of an effective attractive interaction in addition to the screened Coulomb repulsion between two dopants. By analyzing the data through Monte Carlo simulations, we have extracted the intrinsic screening length at different dopant densities and attributed the origin of the effective attraction to strong many-body effects in the dopant-dopant repulsion. {copyright} {ital 1999} {ital The American Physical Society }

The pathogenesis of gluten-sensitive enteropathy is as yet unknown. According to one theory gluten may act as a lectin with toxic properties for the intestinal cells. We can now confirm this theory by laser nephelometric measurements and demonstrate the oligomannosyl specificity of this lectin-like protein gluten. Furthermore, we demonstrate the highly more intensive binding capacity of gluten for the glycoproteins of the immature crypt cells of the intestinal brush border compared to those from the mature villous zone. It is discussed that gluten-sensitive enteropathy is caused by a genetically determined defect-glycosylation of intestinal glycoproteins with the synthesis of more mannosylated glycoproteins.

Reaction of carboxaldehyde 1 with acetone cyanohydrin gives carboxylic acid 2. Reaction of 1 with acetone cyanohydrin in methanol affords the methyl ester 3. The structural assignment for 2 is supported by 13C nmr data and by the decarboxylation of deuterated 2 to give 4b. The internal oxidation-reduction upon going from 1 to 2 is explained in terms of a mechanism whereby 1 is converted into its cyanohydrin 5 and then to acyl cyanide 6. Acyl cyanide 6 then reacts with either water or methanol to give 2 or 3.

The defensive secretions of 4 species of opilionids were analyzed.Leiobunum ventricosum andHadrobunus maculosus produce 4-methylheptan-3-one, whileL. calcar produces E-4,6-dimethyl-6-octen-3-one.L. longipes produces E-4,6-dimethyl-6-nonen-3-one, a new natural product.

Alexander Mikhailovich Butlerov's classic paper of 1861 has not been fully appreciated by western historians of science primarily because it seems to lie outside the mainstream of contemporary thou...