Serum malondialdehyde-like material (MDA-LM) in acute myocardial infarction.

Serum malondialdehyde-like material (MDA-LM), as an index of lipid peroxidation, and the serum enzymes CK, CK-MB, LDH, LDH1 and, alpha-HBDH were evaluated in a group of 26 patients with acute myocardial infarction (AMI), seven with angina pectoris (AP), and in a normal control group of 94 subjects. MDA-LM values were within the normal range in AP patients, while in AMI patients a significant increase in serum MDA-LM was observed in the days following the acute event, reaching a maximum 6-8 days later, when 90% of the patients had values higher than the upper normal limit (mean +/- 2SD) of the control group. A significant correlation was found between the integrated concentration-time MDA-LM curve and the integrated serum enzymes activity curves reached during the nine days after the acute event. The "in vivo" relevance of the increased serum MDA-LM in the post-infarct period is unknown at the present, but as lipid peroxides are known to harm cellular structures and to inhibit prostacyclin synthesis, it may be of interest with regard to the long term secondary effects in AMI patients.     

Case studies in working memory: a case for single cases?

Patterns of cognitive deficit in single neuropsychological cases are common sources of evidence for theories of normal cognition. In particular, the working memory model has benefited from data obtained from a number of contrasting patients, in some cases resulting in modifications of the working memory model. In this paper, patterns of data from short-term memory patients and anarthric patients are compared with patterns of data from normal subjects. The patterns of patient data that were unlike those patterns typically found for groups of normal subjects, could be incorporated within a modified version of the articulatory loop component of the working memory model. However a small number of individual normal subjects also did not show the pattern that is reported on the basis of average performance of groups of normal subjects. This causes some difficulty in interpreting those data from such 'aberrant normal' patterns, and those data from single patients with functional cognitive deficits. The implications of these findings for the interpretation of neuropsychological data are discussed in the context of the working memory model, but with the intention of making a general point pertaining to the development of functional models of cognition. It is argued that single case studies should continue to provide a useful source of evidence, providing that care is exercised in considering the implications of such data for models of normal cognition.     

Seasonality and human in vitro fertilization outcome.

Seasonal changes in spontaneous fecundity have been observed in several human populations, but it is not clear whether the same applies to human in vitro fertilization-embryo transfer (IVF) procedures. In the present study, 2067 patients undergoing their first IVF attempt between the years 1998 and 2003 were grouped into four 'seasons' (December-February, March-May, June-August, September-November) according to the day on which they were administered human chorionic gonadotropin. Several parameters known to affect IVF outcome (including ovarian response to gonadotropins, sperm and oocyte quality, fertilization rate, embryo quality, pregnancy and implantation rates) were considered and potential changes among the four seasonal periods were analyzed. Moreover, some confounding variables (sperm quality, age, duration of infertility, indications for IVF) were controlled for. Overall, pregnancy rate per oocyte pick-up and per embryo transfer of 32.5% and 35.8%, respectively, as well as implantation rate of 18.9%, were recorded. None of the observed IVF-related parameters showed any significant change clearly related to a specific seasonal period, their fluctuations throughout the year being randomly determined. Ovarian responsiveness to gonadotropins, quality of gametes and embryos, and fertilization and implantation processes were apparently not significantly affected by seasonality. It is concluded that the results of a good-quality IVF program in humans are not significantly affected by the season of the year in which the IVF attempt is accomplished; therefore, season is not a relevant factor to be considered when planning an IVF treatment.     

Transmitter histochemistry of the rat olfactory bulb. I. Immunohistochemical localization of monoamine synthesizing enzymes. Support for intrabulbar, periglomerular dopamine neurons.

The rat olfactory bulb was studied at the light and electron microscopic level with the indirect immunofluorescence technique and the unlabelled antibody enzyme method (PAP-technique), respectively. Antibodies to all 4 enzymes in the catecholamine synthesis were used. In the principal bulb the first two enzymes, tyrosine hydroxylase (TH) and DOPA decarboxylase (DDC), but not dopamine-beta-hydroxylase (DBH), were present in a proportion of periglomerular cell bodies and dendrites indicating that these neurons synthesize dopamine (DA). This amine may therefore be released as a transmitter substance at some of the intraglomerular dendrodendritic synapses which periglomerular cells form with the mitral cells. There is evidence to suggest that some periglomerular cells use GABA as their transmitter. Thus, a morphologically and physiologically homogenous population of neurons can be subdivided on the basis of transmitter histochemical criteria. There was an impression of more DDC-positive than TH-positive fibers in the glomeruli. Such presumably DDC-positive, but TH-negative processes may represent 5-hydroxytryptamine (5-HT) nerve terminals. DBH-positive fibers were seen in the granular, external plexiform, and very rarely, in the glomerular layers, probably representing noradrenaline (NA) nerve terminals ascending from the lower brain stem. Weakly fluorescent DDC-positive fibers may represent nerve terminals of ascending 5-HT neurons. No phenylethanolamine-N-methyltransferase (PNMT)-positive neurons were observed.     

New derivatives of pyrrolo and pyrido[2,1-b] quinazoline as antiulcer agents

A series of 3-benzylidene-1,2,3,9-tetrahydro-9-oxopyrrolo-[2,1-b] quinazolinecarboxylic acids and 6-benzylidene-6,7,8,9-tetrahydro-11-oxo-11H-pyrido[2,1-b] quinazolinecarboxylic acid was synthesized and evaluated for their antiulcer activity by the test of inhibition of restraint ulcers in the rat, and for gastric antisecretory activity using the technique of Shay. Some compounds appear potentially useful for therapeutic application.     

Lack of effect of cimetidine on the renin-angiotensin-aldosterone system in man

Summary It is widely accepted that angiotensin II, ACTH and potassium are the major factors controlling the release of aldosterone. Conflicting results have been reported about the role of serotonin, dopamine and histamine. To evaluate the possible involvement of H₂-histaminergic receptors, the effect of intravenous injection of 400 mg cimetidine on the renin-angiotensin-aldosterone system has been evaluated in 10 healthy volunteers. The administration of cimetidine did not induce a significant change in plasma aldosterone level or in its major controlling factors.