Cyclic analogues of Thr6-bradykinin,N8-Lys-bradykinin and endo-Lys8a-vespulakinin 1

Syntheses are described of the endo-Lys^8a-vespulakinin 1 and of cyclo-Thr⁶- and cyclo-N^ε-Lys-bradykinin. The linear peptides covering the entire sequences of endo-Lys^8a-VSK-1 and Thr⁶-BK, and the decapeptide containing all residues constituting Lys-BK, with a Arg-Lys peptide bond involving the ε-amino function of lysine, were prepared by the solid-phase procedure based on Fmoc chemistry. Cyclization was carried out by the diphenylphosphorazide method. The amino-terminal octapeptide sequence of vespulakinin 1, Fmoc-Thr(tBu)-Ala-Thr(tBu)-Thr(tBu)-Arg(Pmc)-Arg(Pmc)-Arg(Pmc)-Gly-OH, and its N^α-Boc-[(Gal β)Thr³, (Gal β)Thr⁴]-analogue, were used to prepare N^α-(1–8 VSK 1)-cyclo-N^ε-kallidin and N^α-[(Gal β)Thr³, (Gal β)Thr⁴, 1–8 VSK 1]-cyclo-N^ε-kallidin. Peptides and glycopeptides were characterized by amino-acid analysis, optical rotation, analytical HPLC and FAB-MS. Consistent with previous findings, preliminary pharmacological experiments on smooth muscle preparations showed that the cyclic, or partially cyclic, analogues were significatively less potent than the linear ones. © Munksgaard 1995.     

Breath-by-breath analysis of oxygen uptake using the Datex Ultima

The Datex Capnomac Ultima monitor combines a sidestream rapidgas analyser with a spirometer. In theory the integral of simultaneousflow and oxygen concentration during inspiration is the inspiredand expired volume of oxygen. From the difference between thesetwo amounts, oxygen consumption (Vo₂ can be estimated. Vo₂ wasmeasured in patients under general anaesthesia and comparedwith that obtained simultaneously using a Datex Deltatrac metabolicmonitor. Two techniques to compensate for the delay in risetime of the oxygen sensor were evaluated. The first method steepenedthe oxygen curve exponentially, and the second used a linearstatistical correction. The linear correlation coefficientsfor Vo₂ between the Ultima and the Deltatrac were 0.87 and 0.78for the two methods. The 10th to 90th centile range for errorwas –67.4–59.8 ml min^–1 for the exponentialmethod and –53.2–56.1 ml min^–1 for the statisticalmethod. The Ultima may be used with moderate accuracy to measureoxygen uptake during anaes thesia.     

Can infant mortality be reduced by promoting breastfeeding? Evidence from Sao Paulo city

An ambitious breastfeeding promotion programme was launchedin Brazil in 1981 which included the use of mass media, healthpersonnel training and re-organization of health service routines.A comparison of two health surveys carried out in Greater SãoPaulo before (1981) and after (1987) the implementation of theprogramme showed an important increase in the median durationof breastfeeding from 84 to 146 days, respectively. The potentialimpact of the programme on infant mortality rates has been estimated,using the relative risks associated with breastfeeding obtainedin a case-control study in a similar urban population in southernBrazil. During this period the infant mortality rate in SãoPaulo fell by 49%. The observed change in feeding practicesmay have been responsible for a reduction of 12% of this 49%or, expressed another way, for one-quarter of the observed declinein infant mortality. The calculations suggest that the programmemay have led to reductions in deaths caused by diarrhoea of32%, in respiratory infections of 22% and in deaths due to otherinfections of 17%.     

Asystole with Syncope Secondary to Hyperventilation in Three Young Athletes

We describe three athletes who had syncope after (case 1) or during (cases 2, 3) hyperventilation. During the episode, ECG showed prolonged sinus arrest. Clinical data and noninvasive investigations were normal and the phenomenon was not reproducible. Electrophysiological study after autonomic blockade allowed a prolonged intrinsic heart rate in case 1, and abnormal corrected sinus node recovery time in cases 1 and 2. During follow-up, symptomatic sinus arrest provoked by deep inspiration occurred in case 3. These cases document prolonged asystole of unknown etiology, secondary to hyperventilation, and probably caused by different vagally-mediated mechanisms.     

The Effect of DDD Pacing on Ergospirometric Parameters and Neurohormonal Activity in Patients with Hypertrophic Obstructive Cardiomyopathy

This study examined the acute and long-term effects of DDD pacing on ergospirometric parameters and neurohormonal activity in patients with hypertrophic obstructive Cardiomyopathy (HOCM). We studied eight patients (five males), aged 56 ± 7 years, with HOCM refractory to drugs. In all patients a DDD pacemaker was implanted and programmed with an atrioventricular (AV) delay that insured full ventricular activation. The patients underwent echocardiographic examination and exercise stress testing before and 3 days, 3 months, and 12 months after pacemaker implantation. Oxygen consumption was measured at the anaerobic threshold (VO_2AT) and peak exercise (pVO₂). Atrial natriuretic peptide (ANP) and cyclic adenosine monophosphate (c-AMP) levels were measured concomitantly. Left ventricular outflow tract (LVOT) pressure gradient decreased significantly from 70 ± 18 to 25 ± 12 mmHg (P < 0.05) 3 days after pacing and remained unchanged at 3 and 12 months. pVO₂ and VO_2AT increased significantly, from 20.1 ± 3 to 23.4 ± 3 mL/kg/min and from 16 ± 3 to 17.8 ± 2 mL/kg/min, respectively (P < 0.05). This improvement continued up to 3 months, and then remained stable until the end of the 12-month follow-up period. ANP levels decreased at 3 days from 85.4 ± 5.7 to 75.4 ± 7.3 fmol/mL (P < 0.05), and remained unchanged over the 12 months. c-AMP levels did not change significantly after the onset of pacing. DDD pacing in patients with HOCM not only reduces the LVOT pressure gradient but also causes a significant early and long-term improvement in exercise capacity and neurohormonal profile.