Predictive Value of Various Types of Ventricular Response to Programmed Ventricular Stimulation: Relation to Holter Monitoring

The study was performed to determine the predictive value of programmed stimulation for identification of pts with ventricular arrhythmias: 75 patients were studied by means of 24-hour ambulatory ECG (24 ECG) and programmed right (in some patients also left) ventricle stimulation at sinus and two or three pacing rates using two (standard) and three extrastimuli or burst stimulation (extensive protocol). Lown classes 0.1–3 and 4a–4h were observed in 24 ECG in 35, 14, and 26 patients, respectively. In programmed stimulation 1–6 repetitive ventricular responses (RVR) were found in 56 pts, nonsustained ventricular tachycardia in 11 and sustained ventricular tachycardia in 21 pts. High incidence of induced VT was found in pts with complex ventricular arrhythmia in 24 ECG, 81% of this group, in all but six pts only standard protocol was used. The 1–6 RVR were observed in almost 40% of pts without any arrhythmia. Conclusion; Only VT induction is a useful index for high risk patients.     

REDUCED DOPAMINERGIC INHIBITION OF THYROTROPHIN RELEASE IN STATES OF PHYSIOLOGICAL HYPERPROLACTINAEMIA

We have tested the hypothesis that physiological puerperal hyperprolactinaemia may be secondary to reduced hypothalamic dopaminergic inhibition of prolactin (PRL) release. Nine post-partum females with physiological hyperprolactinaemia (aged 19–40 years; mean basal PRL±SE, 2099±257 mU/l, range 1002–3762 mU/l) were studied and results compared with fourteen normoprolactinaemic females (basal PRL<400 mU/l; aged 18–36 years). Puerperal hyperprolactinaemic females showed a reduced TSH response to dopamine (DA) receptor blockade with metoclopramide (10 mg i.v.) compared with normal females over a 60-min period following drug administration (total incremental TSH change, mean ±SE, mU/l; 0.5±0.3 v. 3.1±1.0, P<0.005). This finding of reduced dopaminergic inhibition of TSH release in females with physiological puerperal hyperprolactinaemia supports the view that an overall reduction in hypothalamic dopaminergic tone may contribute towards hyperprolactinaemia in post-partum women.     

PREPARATION AND CONFORMATIONAL STUDY OF CLUPEINE FRAGMENTS*

Fragments of clupeines YI, YII, and Z of divergent chain length and different amino acid composition were prepared by digestion with thermolysin and a mixture of carboxypeptidases A and B, and their conformational preferences examined as a function of pH, added salts, presence of a helix-supporting solvent, and temperature. All these highly basic oligopeptides adopt an essentially unordered conformation in aqueous solution. 2-Chloroethanol supports in various amounts the onset of the right-handed α-helical form in the carboxypeptidase fragments.     

BIOLOGICAL SIMILARITIES AND DIFFERENCES BETWEEN RATS GENETICALLY DIFFERENT IN ALCOHOL PREFERENCE

This paper is an inventory of some behavioural, biochemicaland pharmacological similarities and differences between twoinbred strains of Wistar rats differing in voluntary consumptionof ethanol, namely: UChA and UChB with low and high preferencesrespectively for ethanol under conditions involving free choicebetween a 10% (v/v) ethanol solution and distilled water. Thefollowing strain differences were observed: ethanol consumption(UChA<UChB); total water consumption (UChA<UChB); solidfood consumption (UChA>UChB); rate of recovery of ethanollabel in expired CO₂ (UChA<UChB); oxidation of ethanol toacetaldehyde by brain homogenates (UChA>UChB); acetaldehydedisposal by brain homogenates (UChA<UChB); ethanol (90 mmol/kg,i.p.) sleeping-time (UChA<UChB); chronic and acute toleranceto ethanol (UChA developed it, whereas UChB did not); lethaldoses of ethanol (UChA>UChB); recovery rate of the labelof gluconate in expired CO₂ (UChA<UChB); recovery rate ofthe label of fructose in expired CO₂ (UChA<UChB); blood-glucoselevel after glucose (1g/kg, i.p.) load (UChA<UChB). No straindifferences were observed in the rate of recovery in expiredCO₂ of the label of the following substrates: acetate, pyruvate,butyrate, citrate, ribose, glycerol, sorbitol, glucose and galactose.     

Unusual Placement of a Pacemaker Pocket

Because of infection and extensive radiation injury to the skin of the chest wall, a dual chamber pacemaker was implanted deep to the clavicle. The wound has been stable and comfortable for 1 year and pacemaker programming has been unimpaired.