CENTRAL CARDIOVASCULAR EFFECTS OF DIHYDROPYRIDINES IN SPONTANEOUSLY HYPERTENSIVE RATS

Summary— Intracerebroventricular (i.c.v.) injections of dihydropyridine derivatives calcium channel agonist (BAY K8644) and antagonists (nifedipine, nicardipine, PN 200–110) induced opposite long-lasting changes in blood pressure (BP) in pentobarbital anesthetized spontaneously hypertensive rats (SMR). I.c.v. nifedipine (NIF), nicardipine (NIC), and PN 200–110 decreased mean blood pressure dose-dependently and stereoselec-tively, (+) NIC and (+) PN being 8 and 3 times more potent than their (-) isomers, respectively. The decrease in BP was due to a withdrawal of the sympathetic tone, since NIF- and NIC-induced falls in BP were suppressed after either hexamethonium (HXM), 6 OHDA or bilateral adrenalectomy. I.c.v. BAY K8644 increased BP dose-dependently. The i.c.v. BAY K8644-induced hypertensive effect was inhibited: a), by NIF and (+) PN but not by (-) PN, therefore probably occurring at central DHP sites; b), by HXM and reserpine, thus probably mediated by an increase in sympathetic tone; c), by i.c.v. methylatropine (MA) while i.v. MA and i.c.v. HXM had no inhibitory effect, thus probably involving central muscarinic sites. In SHR, NIC did not after the K+-evoked ACh release but suppressed the BAY K8644-induced increase in ACh release. In anesthetized normotensive control rats (WKY), neither i.c.v. NIF, NIC or BAY K8644 changed BP, nor did the latter after ACh release. Moreover, in conscious WKY, i.c.v. nicardipine increased BP and HR while, in conscious SHR it decreased BP without any change in HR. These data suggest that central DHP sites may be involved in the cholinergic transmission and may participate in genetic hypertension via sympathetic tone.     

Peptic proteolysis of esterified β-casein and β-lactoglobulin

Moderate esterification induces slight secondary structure changes in two major milk proteins, β-lactoglobulin and β-casein. Esterification of β-lactoglobulin prompts its tertiary structure‘melting′, opening it to peptic cleavage. Twenty-two new cleavage sites were characterised in β-lactoglobulin and five in β-casein. Some of them are due to esterification-improved peptide bond accessibility, some to the bias of pepsin specificity by glutamate and aspartate esters. The resulting fragmentation yields original and partially amphiphilic peptide populations.     

EVALUATION IN YOUNG CHILDREN OF THE URABE AM 9 STRAIN OF LIVE ATTENUATED MUMPS VACCINE IN COMPARISON WITH THE JERYL LYNN STRAIN

ABSTRACT. Urabe Am 9, a new strain of mumps vaccine, originally developed in Japan, was evaluated in children 14 to 20 months of age in a comparative trial with the Jeryl Lynn strain. Both vaccines performed well. The antibody responses were measured using a neutralization test and a haemolysis-in-gel test. The seroconversion rates at six weeks, as detected with either one or both tests, were 55/58 (94.8%) after the Urabe Am 9 and 58/60 (96.7%) after the Jeryl Lynn vaccine. Only mild infrequent adverse reactions were observed. It is concluded that both strains of live attenuated mumps vaccine are immunogenic and well-tolerated in this age group.     

COMPARISON OF THE URABE AM 9-SCHWARZ AND JERYL LYNN-MORATEN COMBINATIONS OF MUMPS-MEASLES VACCINES IN YOUNG CHILDREN

ABSTRACT. Two mumps-measles vaccine combinations were evaluated for their reactogenicity and immunogenicity in children aged 14 to 20 months. The Urabe Am 9-Schwarz combination vaccine was given to 108 double seronegative children. The seroconversion rate at six weeks after vaccination was 99.1% for measles (haemagglutination-inhibition test) and 92.6% for mumps (neutralization and haemolysis-in-gel tests). The Jeryl Lynn-Moraten vaccine was administered to 85 double seronegative children; the seroconversion rates were 95.3% for measles and 83.5% for mumps. The reported post-vaccination signs and symptoms resembled those seen after monovalent measles vaccine but were more accentuated. Fever over 37.5C° was reported in 66.7% and unusual restlessness and irritability in 68.5% of the Urabe Am 9-Schwarz double seronegative vaccinees compared to 55.3% ( p <0.05) and 54.1 % ( p <0.05), respectively, in the recipients of the Jeryl Lynn-Moraten vaccine. These relatively high reaction rates probably reflect the close observation of the children by their parents during the study. Nevertheless, the tendency towards increased reaction rate and, possibly, reduced immunogenicity of bivalent mumps-measles vaccines as compared to the corresponding single vaccines should be taken into account in the planning of large scale vaccination of young children.