Showing papers by "University of Cagliari published in 1989"

A case-control study of gastric cancer and diet in Italy.

Abstract: A case-control study was conducted in high- and low-risk areas of Italy to evaluate reasons for the striking geographic variation in gastric cancer (GC) mortality within the country. Personal interviews with 1,016 histologically confirmed GC cases and 1,159 population controls of similar age and sex revealed that the patients were more often of lower social class and resident in rural areas and more frequently reported a familial history of gastric (but not other) cancer. After adjusting for these effects, case-control differences were found for several dietary variables, assessed by asking about the usual frequency of consumption of 146 food items and beverages. A significant trend of increasing GC risk was found with increasing consumption of traditional soups, meat, salted/dried fish and a combination of cold cuts and seasoned cheeses. The habit of adding salt and the preference for salty foods were associated with elevated GC risk, while more frequently storing foods in the refrigerator, the availability of a freezer and use of frozen foods lowered risk. Reduced GC risk were associated with increasing intake of raw vegetables, fresh fruit and citrus fruits. Lowered risk was also related to consumption of spices, olive oil and garlic. Neither cigarette smoking nor alcoholic beverage drinking were significantly related to GC risk. The case-control differences tended to be consistent across geographic areas, despite marked regional variations in intake levels of certain foods. The high-risk areas tended to show higher consumption of food associated with elevated risk (traditional soups, cold cuts) and lower consumption of foods associated with reduced risks (raw vegetables, citrus fruits, garlic). Our findings indicate that dietary factors contribute to the regional variation of stomach cancer occurrence in Italy, and offer clues for further etiologic and prevention research.

SCH 23390 blocks drug-conditioned place-preference and place-aversion: anhedonia (lack of reward) or apathy (lack of motivation) after dopamine-receptor blockade?

Abstract: The influence of the D1 antagonist SCH 23390 on the motivational properties of rewarding (morphine, nicotine and diazepam) and aversive (naloxone, phencyclidine and picrotoxin) drugs was studied in the rat in a two-compartment place-conditioning paradigm, which included a pre-conditioning test for spontaneous place-preference. The specific D1 dopamine-receptor antagonist SCH 23390 (0.05 mg/kg SC), paired with both compartments or, separately, with the preferred or with the non-preferred compartment, failed to affect the spontaneous unconditioned preference of the animal. Pairing of morphine (1.0 mg/kg SC), nicotine (0.6 mg/kg SC) or diazepam (1.0 mg/kg IP) with the less preferred compartment induced significant preference for that compartment. Pairing of SCH 23390 (0.05 mg/kg SC) with both compartments completely blocked the place-preference induced by morphine, nicotine and diazepam. Naloxone (0.8 mg/kg SC), phencyclidine (2.5 mg/kg SC) or picrotoxin (2.0 mg/kg IP) paired with the preferred compartment elicited place-aversion. Pairing of SCH 23390 (0.05 mg/kg SC) with both compartments abolished also the place-aversion induced by naloxone, phencyclidine and picrotoxin. The results indicate that blockade of dopamine transmission blocks the motivational properties of rewarding as well as aversive stimuli. It is suggested that neuroleptics rather than simply blocking the rewarding impact of positive reinforcers (anhedonia, lack of pleasure) exert a more general influence on conditioned behaviour by blocking the affective impact of negative as well as positive reinforcers (apathy, lack of motivation).

More on smoking habits and Graves' ophthalmopathy.

Abstract: Since a relationship between cigarette smoking and the occurrence of Graves' ophthalmopathy has been recently postulated, we reviewed the smoking habits of 1730 women, including subjects without thyroid disease, with nontoxic goiter (NTG), toxic nodular goiter or toxic adenoma (TNG), Hashimoto's thyroiditis (HT), Graves' disease without ophthalmopathy (GD) or with ophthalmopathy (GO) The prevalence of smokers in NTG, TNG and HT was about 30%, not different from that of controls Smokers were 479% in GD and 642% in GO groups The latter figures were highly different from those of the other groups and also from each other The percentage of heavy smokers was higher in patients with more severe ophthalmopathy No clear explanation for this phenomenon can be offered The absence of a high prevalence of smokers among patients with non-toxic goiter, nonautoimmune hyperthyroidism and Hashimoto's thyroiditis, limits the impact that smoking might have had in the pathogenesis of goiter, hyperthyroidism and autoimmune phenomena of GD and GO

5HT3 receptor antagonists block morphine- and nicotine- but not amphetamine-induced reward.

Abstract: The effect of two potent and specific antagonists of 5HT3 receptors, ICS 205-930 and MDL 72222, on the reinforcing properties of amphetamine, morphine and nicotine was studied in rats. Durg-induced reinforcement was assessed by measuring drug-conditioned place preference. ICS 205-930 and MDL 72222 dose-dependently reduced the place preference induced by morphine (1.0 mg/kg SC). At doses of 0.030 mg/kg SC the two antagonists completely blocked morphine-induced place preference while doses of 0.015 mg/kg SC significantly reduced it. ICS 205-930 and MDL 72222 at doses of 0.030 mg/kg SC also prevented the place preference induced by nicotine (0.6 mg/kg SC). In contrast, ICS 205-930 and MDL 72222 up to doses of 0.030 mg/kg SC failed to modify the place preference elicited by amphetamine (1.0 mg/kg SC). The results indicate that 5HT3 receptors are specifically involved in the reinforcing properties of morphine and nicotine.

Depression among elderly people. A psychosocial study of urban and rural populations.

Abstract: A total of 317 elderly subjects randomly selected among people living in the community in 1 urban and 2 rural areas were studied by means of a semistructured clinical interview, the Social Adjustment Scale, and the Beck Depression Inventory. An emerging trend was demonstrated towards a higher rate of prevalence of depression among females and urban residents. Widowhood, absence of a confidant, poor education and financial difficulties (only among urban elderly people) were significantly correlated with rates of depression. Physical impairments and diseases were also associated with depression, independently of whether subjects lived alone. The findings are discussed using a psychosocial frame of reference.

Suppression by gamma-hydroxybutyric acid of ethanol withdrawal syndrome in rats.

Abstract: The ability of gamma-hydroxybutyric acid to suppress ethanol withdrawal syndrome was tested in male rats rendered physically dependent on ethanol by several intragastric administrations of ethanol (9-15 g/kg daily for 7 days). Gamma-hydroxybutyrate (0.25, 0.50 and 1.00 g/kg i.p.), administered 8 hr after the last ethanol dose, produced a dose-dependent inhibition of withdrawal signs such as tremors and audiogenically-induced seizures; the highest dose tested suppressed all ethanol withdrawal symptoms.

Prenatal diagnosis of β‐thalassaemia in Mediterranean populations by dot blot analysis with DNA amplification and allele specific oligonucleotide probes

Abstract: In this study, we describe a simple strategy to detect β-thalassaemia mutations in prospective parents and to make prenatal diagnosis in pregnancies at risk in the Mediterranean population. Screening of prospective parents is carried out by dot blot analysis on enzymatically amplified DNA with a set of oligonucleotide probes complementary to the most common mutations in this population. Prenatal diagnosis is accomplished by the same procedure on enzymatically amplified amniocyte or trophoblast DNA. The main advantages of this procedure are the simplicity, sensitivity (0.05 μg of DNA), and rapidity (12–24 h). Further simplification is obtained by amplification of the DNA from crude amniotic cell lysate. The very low amount of fetal material necessary for this analysis eliminates the need to culture amniotic fluid cells and may decrease the fetal loss rate associated with trophoblast sampling. The number of specific DNA sequences obtained by the amplification procedure allowed us to use non-radioactive labelled oligonucleotide probes, which have several advantages compared to radioactive probes.

Calcium-dependent, tetrodotoxin-sensitive stimulation of cortical serotonin release after a tryptophan load.

Abstract: The effect of intraperitoneal administration of tryptophan (50, 100, or 200 mg/kg) on extracellular concentrations of tryptophan, serotonin (5-hydroxytryptamine, 5-HT), and 5-hydroxyindoleacetic acid (5-HIAA) was studied in the cortex of freely moving rats by transcerebral dialysis. Rats were implanted with dialysis probes in the frontal cortex, and experiments were performed 24 h later. Tryptophan, 5-HT, and 5-HIAA were quantified in 20-min samples of dialysate by HPLC with electrochemical detection after separation on reverse-phase columns. Tryptophan administration resulted in a significant increase of tryptophan, 5-HT, and 5-HIAA levels in dialysates. The maximal increase of 5-HT and 5-HIAA output was approximately 150% over basal values. Perfusion with Ringer's solution containing tetrodotoxin (1 microM) reduced 5-HT output by 90% and prevented the increase of 5-HT and 5-HIAA content after 100 mg/kg of tryptophan. Similar results were obtained after perfusion with Ringer's solution without Ca2+. The results indicate that a tryptophan load stimulates the physiological release of 5-HT.

The prevention of thalassemia in Sardinia.

Abstract: In this paper we review the characteristics and effectiveness of a program aimed at preventing homozygous beta-thalassemia in the Sardinian population. The target population for screening were couples at marriage, conception or early pregnancy. Awareness of the problem and the involvement of the population were achieved via the mass media or by personal approaches through lectures or discussions. Parents' Associations were consulted and have made themselves available to prospective couples in several critical areas. Education on thalassemias was introduced into the school curriculum. Counseling was based on private interviews at which the several options available were discussed with the individual carrier or the couples. Prenatal diagnosis was chosen by the large majority of couples counseled. The introduction of 1st trimester diagnosis resulted in a striking increase of the acceptance rate from 93.2 to 99.1%. Prenatal diagnosis was carried out initially by fetal blood analysis and thereafter by trophoblast or amniocyte DNA analysis. Direct detection of the mutation by oligonucleotide hybridization on agarose gel separated DNA fragments or by dot-blot analysis with allelic specific oligonucleotide probes on enzymatically amplified DNA was used. This program resulted in a decline in thalassemia major births of 90%. The reasons for residual cases were mostly lack of information and, less frequently, misdiagnoses or refusal of fetal diagnosis.

Apomorphine stimulation of male copulatory behavior is prevented by the oxytocin antagonist d(CH2)5 Tyr(Me)-Orn8-vasotocin in rats.

Abstract: The effect of the intracerebroventricular (ICV) injection of the oxytocin antagonist d(CH2)5Tyr(Me)-Orn8-vasotocin on the stimulation of copulatory behavior induced by the dopamine (DA) agonist apomorphine was studied in male rats. Apomorphine (80 micrograms/kg SC) given 5 min before mating tests decreased intromission frequency and ejaculation latency in experienced male rats. Such effects were abolished and reversed by pretreatment with 50 and 1000 ng of the oxytocin antagonist given ICV 5 min before apomorphine. The peptide per se markedly increased intromission and ejaculation latency and abolished ejaculation in control rats. The results suggest that brain oxytocin is implicated in the expression of sexual behavior, and apomorphine might improve male copulatory behavior by releasing oxytocin in brain.

Kinetics of multimonomer emulsion polymerization. The pseudo-homopolymerization approach

Abstract: By generalizing the Smith–Ewart theory, a system of polymer particle population balances is developed for describing the kinetics of emulsion polymerization processes involving any number of monomer species. Each population is characterized by the number of active radicals of each type present inside each particle, and described through a size distribution function. An approximation procedure is proposed for reducing the original system to that typical of homopolymerization processes, thus characterizing each population-only through the overall number of radicals, without any significant loss of accuracy. The reliability of such “pseudo-homopolymerization approach” is tested by comparison with polymer composition vs. monomer conversion experimental data for the ternary system acrylonitrile–styrene–methyl methacrylate.

Comparison between the results of an automatic and a visual scoring of sleep EEG recordings.

Abstract: In this paper, results from the visual scoring of nocturnal polygraphic recordings, carried out by nine different groups of readers from different Italian sleep laboratories, are analyzed; inter-and intragroup variability is shown and statistically discussed. Data are then compared with the results of an automatic scoring of the same recordings, carried out by the Medilog Sleep Stager. The validity of this automatic method of scoring is discussed. Finally, an epoch by epoch analysis is described, with the aim of achieving a more detailed evaluation of the intergroup variability.

Cell deletion by apoptosis during regression of renal hyperplasia.

Abstract: Regression of renal hyperplasia after withdrawal of the mitogenic stimulus induced by a single injection of lead nitrate was studied in male Wistar rats. Lead nitrate administration (10 mumol/100 g body weight) resulted in a ninefold increase in the incorporation of labeled thymidine into renal DNA and in an enhancement in the mitotic index; these changes were accompanied by an increase in the organ weight and DNA content that reached a maximum at 2 days. Regression of the renal hyperplasia was observed as early as 3 days after treatment and was completed within 2 weeks. Although lytic necrosis was not responsible for cell loss, the elimination of the excess renal cells took the form of apoptosis. This distinctive mode of cell death, which has been implicated in the involution of hyperplasia in other tissues and organs, was characterized by the occurrence of intracellular and extracellular membrane-bounded eosinophilic globules that often contained nuclear fragments. It affected mainly cells of the proximal tubules, and it was not detected once the kidney had regressed to its original mass. These results support the hypothesis that apoptosis is involved in the regulation of organ size.

Oxygen-binding properties of cephalopod blood with special reference to environmental temperatures and ecological distribution

Abstract: The oxygen-binding properties of the blood of the cephalopods Todarodes sagittatus, Loligo vulgaris, Architeuthis monachus, and Octopus vulgaris were studied in relation to temperature and pH. The data obtained at pH 7.4 were compared with previously reported data on nine species of cephalopod over the actual range of temperatures at which the animals live in an attempt to define the role of temperature as an effector in the process, and to demonstrate the extent to which temperature influences the ecological range of the various species. For most cephalopods we found Bohr and Haldane factors of lower than −1.0, a result that implies that the Bohr shift does not facilitate the unloading of O2, but may improve the loading of O2 with increased ventilation. The functional significance of the Bohr and Haldane effects appears, thus, to involve stabilization of pH by the isohydric transport of CO2. Our results further demonstrated a significant decrease in oxygen affinity with temperature for all cephalopods studied. This relationship was more pronounced for the cephalopods from colder waters than for those from the tropics. Furthermore, a significant increase in cooperativity with decreasing affinity for oxygen was found when we compared these oxygen-binding parameters at pH 7.4 and at the temperatures of the natural habitats of the various cephalopods. The respective relationships between the Hill coefficient (n50) and the oxygen tension at half-saturation (P50) allowed us to separate the cephalopods into three distinct groups: 1) the Sepia species; 2) all the squids except Architeuthis; and 3) all the Octopus species, plus Architeuthis and Nautilus, this third group being the most sluggish group examined. Furthermore, the most sluggish species, those in group 3, have the highest reported functional buffer capacities, 7–19 mM CO2 · pH−1 · mM O2−1, while the more active species have functional buffer capacities in the range of 4–7 mM CO2 · pH−1 · mM O2−1. The relationship between P50 and n50 optimizes the utilization of O2 over the entire range of P50 reported.