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Biomedical subjects

G Costa

Publications and source records attributed to G Costa.

At least 127 records · Page 7Linked to original sources
PubMed1996

Occupation and ischemic heart disease in the European Community: a comparative study of occupations at potential high risk.

Four longitudinal studies of mortality and morbidity by occupation based on individual record linkage of information and two cross-sectional studies of mortality were compared in order to identify occupations at high risk of ischemic heart disease. In more than one country an increased risk of ischemic heart disease was found in drivers of buses, taxies, and lorries, in bakers, in naval officers and fishermen, in hotel and restaurant workers, in senior police, customs, and other uniformed men, in barbers and hairdressers, in warehouse and wholesale staff, as well as in laboratory assistants and in radio and telegraph operators. Occupations found at high risk in Denmark were also found at high risk in Great Britain and Italy. These occupations may be at genuine high risk. None of these groups work day-work only and several of the groups have psychologically demanding work but unsatisfactory decision authority. Identification of occupations at high risk may help to develop focused preventive strategies.

Adolescent↗
PubMed1996

Is there a causal connection between bile acids and colorectal cancer?

Bile acid composition was assessed in 50 patients with colorectal cancer as compared to that in a control group of 50 subjects. The two groups were age- and sex-matched. The overall bile acid values were similar in both groups, while the relative concentrations of primary and secondary bile acids were different, a significant increase in the patients with colorectal cancer being observed. This finding thus seems to confirm the existence of a link between colorectal cancer and cholelithiasis. Both conditions share common risk factors, such as alterations in cholesterol metabolism and bile acid composition.

Adult↗
PubMed1996

Meiotic segregation and recombination of the intergenic spacer of the ribosomal DNA in the ectomycorrhizal basidiomycete Laccaria bicolor.

The aim of this study was to clarify the inheritance of the nuclear ribosomal DNA (rDNA) in the ectomycorrhizal basidiomycete Laccaria bicolor S238N in order to resolve inter- and within-strain relationships in forest ecosystems. PCR amplification of the intergenic spacer (IGS) was carried out in the dikaryotic mycelium and its haploid progeny. In the dikaryotic mycelium, multiple amplification products were produced for the 25s/5s (IGS1) and 5s/17s (IGS2) intergenic spacers. The 4.5- and 4.0-kb fragments of IGS2 (haplotypes alpha and beta, respectively) were observed to occur in a 1:1 ratio within the haploid progeny as a result of divergent IGS haplotypes in the two separate nuclei. Recombinant monokaryons having both types of IGS2 occurred at a low frequency (6.5%; 60 kb per centimorgan) during meiosis. Haplotypes alpha and beta of IGS1 cross-hybridized forming heteroduplexes during the PCR temperature cycle. The two IGS1 haplotypes differed only by the repeat number of a TA2C3 motif and co-segregated with the IGS2 haplotypes. Heteroduplex formation and IGS polymorphism provide information that is helpful in distinguishing between introduced exotic L. bicolor S238N and indigenous populations of Laccaria spp. in forest ecosystems.

Agaricales↗
PubMed1996

The impact of shift and night work on health.

Shift work, in particular night work, can have a negative impact on health and well-being of workers as it can cause: (a) disturbances of the normal circadian rhythms of the psychophysiological functions, beginning with the sleep/wake cycle; (b) interferences with work performance and efficiency over the 24 hour span, with consequent errors and accidents; (c) difficulties in maintaining the usual relationships both at family and social level, with consequent negative influences on marital relations, care of children and social contacts; (d) deterioration of health that can be manifested in disturbances of sleeping and eating habits and, in the long run, in more severe disorders that deal prevalently with the gastrointestinal (colitis, gastroduodenitis and peptic ulcer), neuro-psychic (chronic fatigue, anxiety, depression) and, probably, cardiovascular (hypertension, ischemic heart diseases) functions. Besides, shift and night work may have more specific adverse effects on women's health both in relation to their particular hormonal and reproductive function, and their family roles. It has been estimated that about 20% of all workers have to leave shift work in a very short time because of serious disturbances; those remaining in shift work show different levels of (mal)adaptation and (in)tolerance, that can become more or less manifest in different times, and with different intensity. In fact, the effects of such stress condition can vary widely among the shift workers in relation to many 'intervening variables' concerning both individual factors (e.g. age, personality traits, physiological characteristics), as well as working situations (e.g. work loads, shift schedules) and social conditions (e.g. number and age of children, housing, commuting).

Journal Article↗
PubMed1996

Effect of 2,6-diisopropylphenol on the delayed hippocampal cell loss following transient forebrain ischemia in the gerbil.

We examined the protective activity of 2,6-diisopropylphenol on mortality and delayed hippocampal cell death induced by transient cerebral ischemia in the gerbil. Forebrain ischemia was produced by bilaterally occluding the common carotid arteries for 10 minutes; then the blood supply to the brain was restored. The number of survivors was counted for 8 days, and the histopathological damage in the CA1 region of the hippocampus was scored according to the semiquantitative scale of Rudolphi and Colleagues. When intraperitoneally injected immediately after the ischemic attack, 2,6-diisopropylphenol (25, 50, 100 mg kg-1) produced no significant reduction in the rate of mortality in comparison with its vehicle. However, the survivors that had received the compound at the dose of 50 and 100 mg kg-1 elicited a significant increase in the number of viable pyramidal cells in the CA1 hippocampal region. Moreover, we obtained similar results by injecting the compound 30 minutes after the release of the carotid artery occlusion. These results suggest that 2,6-diisopropylphenol, although it does not show any capability of improving the rate of survival, it elicits protective properties against the transient forebrain ischemia-induced delayed hippocampal neuronal death.

Animals↗
PubMed1996

Local regulation of oviductal blood flow.

1. Blood flow to the oviduct is implicated in the genesis and maintenance of oviductal fluid, in this way contributing to the creation of an adequate medium for ovum/embryo physiology. Therefore, factors controlling the tone of the vessels supplying the oviduct would be expected to affect its luminal environment. In addition, cyclic changes in oviductal blood flow have been suggested to have mechanical functions in the transport of the ovum/embryo. 2. The vascular supply to the oviduct has a prominent adrenergic vasomotor control. A dense adrenergic innervation, together with the presence of a predominant population of alpha(1)-adrenoceptors, provides a contractile regulatory mechanism of oviductal blood flow. No evidence is available on the presence of beta-adrenoceptors. The scanty cholinergic innervation of mammalian oviduct is mainly confined to the vessels, where acetylcholine (ACh) has a vasodilatory effect by releasing endothelium-derived relaxing factors. 3. The presence of nerves containing neuropeptides has been shown in the oviduct. Specifically, a high density of neuropeptide Y- and vasointestinal peptide-containing nerve fibers has been found in relation to blood vessels, but their role in the neutral control of the oviduct blood flow remains to be established. To date, it is not known whether or not oviductal blood vessels receive perivascular nitrergic nerves. 4. Relaxing and contracting factors derived from endothelium also seem to have a modulatory role on oviductal vascular tone. Neurotransmitters or autacoids, such as ACh and histamine, acting on endothelial receptors, release nitric oxide (NO), which relaxes oviductal arteries through guanylyl cyclase activation and accumulation of cyclic GMP. In addition, the release of an endothelium-derived hyperpolarizing factor (EDHF), distinct from NO, by ACh has been shown in oviductal arteries. It acts through the opening of low-conductance Ca(2+)-activated K+ channels leading to hyperpolarization and relaxation. Furthermore, potent and long-lasting contractions induced by the endothelium-derived contractile factor, endothelin (ET), points to its role in the long-term regulation of oviductal vascular tone. 5. A particularly high density of 5-hydroxytryptamine (5-HT) and histamine, present in mast cells clustered in the vicinity of blood vessels, has been described in the oviduct. It is known that histamine elicits a relaxation of oviductal arteries that is partially endothelium-dependent and mediated by the activation of H1-receptors. The implication of histamine in both the increase in blood flow and edema around ovulation, as well as the existence of a functional antagonism between histamine and 5-HT in the regulation of oviductal blood flow, await further investigation. 6. Other factors, such as relaxing and contracting cyclooxygenase-derived products, may also participate in the modulation of blood flow to the oviduct. 7. An overall endocrine regulation of the oviductal vascular supply exists, acting by both direct effects on smooth muscle and modulation of neural and autocrine factors. This control enables cyclic changes in blood flow to the oviduct that are tightly coupled to the reproductive functions of the tube.

Adrenergic Fibers↗
PubMed1996

Ultrasonic parameters of bone in young normals: effect of age and sex.

This study was carried out in order to investigate the early effects of ageing on both broadband ultrasound attenuation and speed of sound through the os calcis. A total of 217 normal subjects, subdivided into 113 fertile women (age range 18-51 years, mean +/- 1 SD=29.4 +/- 8.4 years) and 104 age-matched men (age range 20-49 years, mean +/- 29.3 +/- 7.1 years), were investigated. Mean broadband ultrasound attenuation values in men (127.3 +/- 12.8 dB MHz-1) were significantly higher than those found in women (118.3 +/- 17.2, P < 0.001), whereas no significant differences were found as far as mean speed of sound values was concerned. Both broadband ultrasound attenuation (r = -0.196, P < 0.046) and speed of sound (r = -0.226, P < 0.02) values were inversely related to age in men; only a decrease of speed of sound values with age was noted in women (r = -0.400, P < 0.001). Finally, there was a very high significant correlation between broadband ultrasound attenuation and speed of sound values in men (r = 0.458, P < 0.001), but this was lacking in women. Admitting that the measurement of broadband ultrasound attenuation is influenced not only by bone density but also by trabecular quantity, spacing and orientation, our results seem to indicate that, even during adulthood, and well before the deleterious effects of oestrogen lack become apparent, structural properties of skeletal tissue in female subjects are disadvantageous with respect to those found in male subjects. Furthermore, while there is a progressive and balanced involvement of both the elastic (as reflected by speed of sound) and the structural properties of skeletal tissue of men, an uncoupling between the two is typical of women.

Adolescent↗
PubMed1996

The long-term outcome of hepaticojejunostomy in the treatment of benign bile duct strictures.

OBJECTIVE: The authors review the treatment and outcome of patients with benign bile duct strictures who underwent biliary enteric repair. SUMMARY BACKGROUND DATA: The authors conducted a retrospective review of all clinical records of patients referred for treatment of benign bile duct strictures caused by surgery, trauma, or common bile duct lithiasis or choledochal cyst. The authors performed univariate and multivariate analyses of clinical and pathologic factors in relation to patient outcome and survivals. METHODS: Eighty-four patients with documented benign bile duct strictures underwent hepaticojejunostomy, choledochojejunostomy, and intrahepatic cholangiojejunostomy during a 15-year period (January 1975 to December 1989). Morbidity, mortality, and patient survival rates were measured. RESULTS: Early and late outcomes correlated neither with demographic and clinical features at presentation nor with etiologic or pathologic characteristics of the stricture. Best results correlated with high biliary enteric anastomoses and degree of common bile duct dilatation independently of bile duct stricture location. CONCLUSIONS: High biliary enteric anastomosis provides a safe, durable, and highly effective solution to the problem of benign strictures of the bile duct. Transanastomotic tube stenting is unnecessary. Endoscopic and percutaneous transhepatic dilatation seems more appropriate for the treatment of patients in poor condition and those with anastomotic strictures.

Adult↗
PubMed1996

Characterization of nitric oxide synthase activity in sheep urinary tract: functional implications.

1. To define further the role of nitric oxide (NO) in urinary tract function, we have measured the presence of nitric oxide synthase (NOS) activity, and its relationship with functional NO-mediated responses to electrical field stimulation (EFS) in the urethra, the detrusor and the ureter from sheep. NOS activity was assayed by the conversion of L-[14C]-arginine to L-[14C]-citrulline. Endogenous production of citrulline was confirmed by thin layer chromatography. 2. NOS enzymatic activity was detected in the cytosolic fraction from tissue homogenates with the following regional distribution (pmol citrulline mg-1 protein min-1): urethra (33 +/- 3.3), detrusor (13.1 +/- 1.1) and ureter (1.5 +/- 0.2). No activity was detected in the particulate fraction of any region. 3. NOS activity was dependent on Ca(2+)-calmodulin and required exogenously added NADPH and tetrahydrobyoptein (BH4) for maximal activity. Exclusion of calmodulin from the incubation mixture did not modify NOS activity, but it was significantly reduced in the presence of the calmodulin antagonist, calmidazolium, suggesting the presence of enough endogenous calmodulin to sustain the observed NOS activity. 4. NOS activity was inhibited to a greater extent by NG-nitro-L-arginine (L-NOARG) and its methyl ester (L-NAME) than by NG-monomethyl-L-arginine (L-NMMA), while 7-nitroindazole (7-NI) was a weak inhibitor and L-cannavine had no effect. 5. Citrulline formation could be inhibited by superoxide dismutase in an oxyhaemoglobin-sensitive manner, suggesting feedback inhibition of NOS by NO. 6. EFS induced prominent NO-mediated relaxations in the urethra while minor or no responses were observed in the detrusor and the ureter, respectively. Urethral relaxations to EFS were inhibited by NOS inhibitors with the rank order of potency: L-NOARG = L-NAME > 7-NI > L-NMMA. 7. In conclusion, we have demonstrated the presence of NO-synthesizing enzymatic activity in the sheep urinary tract which shows similar characteristics to the constitutive NOS isoform found in brain. We suggest that the enzymatic activity measured in the urethral muscle layer may account for the NO-mediated urethral relaxation during micturition whereas regulation of detrusor and ureteral motor function by NOS containing nerves is less likely.

Animals↗
PubMed1996

[The role of identification of the recurrent laryngeal nerve in thyroid surgery].

Recurrent laryngeal nerve paralysis in the most serious complication of thyroid surgery. Five-hundred and sixty eight-consecutive operations for benign disease of the thyroid were retrospectively analyzed. Bilateral identification of the inferior laryngeal nerve was performed in 447 cases, whereas in 121 patients the identification was unilateral. The rate of primary postoperative vocal cord paralysis was 3.7% and permanent palsy rate was 0.8%. Present results compared with those of Literature confirm that recurrent nerve paralysis is a less frequent complication when the nerve is routinely identified and correctly prepared.

Female↗
PubMed1995

Cancer mortality by educational level in Italy.

Social differences in health concern both ethics and science. From a public health point-of-view, one must assess actual differences and then try to find explanations. This was made possible for the first time for cancer in Italy via nationwide record-linkage between the 1981 census and the national death index. Over the subsequent six months after census, the study-base included 31,000 deaths for cancer and 18 million person-years at risk. Rate ratio (RR) were estimated through a Poisson regression model adjusted by age and geographic area of residence. Educational level was used as social level indicator. Profound social differences were evident for buccal cavity (RR = 3.10 for lowest cf highest educational level), esophagus (RR = 3.00), stomach (RR = 3.43), and larynx (RR = 3.30) among men, and for stomach (RR = 2.25) and uterus (RR = 1.76) among women. Colon (RR = 0.62) and pancreas cancers (RR = 0.65) presented an inverse relationship among men, as did colon (RR = 0.37), breast (RR = 0.56), ovary (RR = 0.45), and melanoma (RR = 0.62) among women. In conclusion, the Italian population at the beginning of the 1980s had large social differences in the risk of dying from cancer, confirming the patterns commonly found in such other countries as Great Britain, France, and New Zealand. Some dissimilarities, useful for hypothesis generation on the mechanisms of inequality, were evident, such as the generally highest social differences found among northern Italian men and among southern Italian women.

Adult↗
PubMed1995

Endothelium-dependent relaxation to acetylcholine in bovine oviductal arteries: mediation by nitric oxide and changes in apamin-sensitive K+ conductance.

1. Mechanisms underlying the relaxant response to acetylcholine (ACh) were examined in bovine oviductal arteries (o.d. 300-500 microns and i.d. 150-300 microns) in vitro. Vascular rings were treated with indomethacin (10 microM) to prevent the effects of prostaglandins. 2. ACh elicited a concentration-related relaxation in ring segments precontracted with noradrenaline (NA), which was abolished by endothelium denudation. 3. The ACh-induced relaxation was attenuated but not abolished by NG-nitro-L-arginine (L-NOARG, 1 microM-1 mM), an inhibitor of nitric oxide (NO) formation. The inhibition caused by L-NOARG (10 microM) was reversed by addition of excess of L-arginine but not D-arginine (1 mM). 4. In high K+ (40-60 mM)-contracted rings, ACh was a much less effective vasodilator and its relaxant response was completely abolished by L-NOARG (100 microM). 5. In NA (10 microM)-contracted rings, ACh induced sustained and concentration-dependent increases in cyclic GMP, which were reduced below basal values by L-NOARG (100 microM), while potent relaxation persisted. Similar increases in cyclic GMP were evoked by ACh in high K+ (50 mM)-treated arteries and under these conditions, both cyclic GMP accumulation and relaxation were L-NOARG-sensitive. 6. S-nitroso-L-cysteine (NC), a proposed endogenous precursor of endothelial NO, also induced cyclic GMP accumulation in NA-contracted oviductal arteries. 7. Methylene blue (MB, 10 microM), a proposed inhibitor of soluble guanylate cyclase, inhibited both endothelium-dependent relaxation to ACh and endothelium-independent response to exogenous NO, whereas relaxation to NC remained unaffected. 8. The L-NOARG-resistant response to ACh was not affected by either ouabain (0.5 mM), glibenclamide (3 microM), tetraethylammonium (TEA, 1 mM) or charybdotoxin (50 nM), but was selectively blocked by apamin (0.1-1 microM). However, apamin did not inhibit either relaxation to ACh in high K(+)-contracted rings or endothelium-independent relaxation to either NO or NC. 9. Apamin and MB inhibited ACh-induced relaxation in an additive fashion, suggesting the involvement of two separate modulating mechanisms. 10. These results suggest that ACh relaxes bovine oviductal arteries by the release of two distinct endothelial factors: a NO-like substance derived from L-arginine, which induces cyclic GMP accumulation in smooth muscle, and another non-prostanoid factor acting by hyperpolarization mechanisms through alterations in apamin-sensitive K+ conductance.

Acetylcholine↗
PubMed1995

Glutathione in the upper respiratory tract.

Glutathione (GSH), a major extracellular antioxidant, has been found in high concentrations in the epithelial lining fluid of the lower respiratory tract. The GSH concentrations in nasal fluid, in normal and pathologic conditions, were investigated and found to be very low. A GSH aerosol (600 mg daily for 10 days) increased GSH levels in the nasal mucosa and induced a statistically significant improvement in nasal obstruction, rhinorrhea, and ear fullness. Thus, GSH administered by aerosol could be a means of defending the epithelial respiratory cells against a toxic oxidant.

Adolescent↗
PubMed1995

[Indirect morbidity indicators and social differences in the ISTAT quarterly workforce survey].

Information on the health condition job related of the population are often collected in specific studies, usually limited over time and concerned with a small part of the general population. Looking at official statistics, sources such as national health surveys (in Europe and in North America) are rich on health data, but often offer little information on job-conditions, and job history. On the other hand, one also can find official sources, mainly concerned with labour and job related topics, in which information related to the health status of the people interviewed are routinely collected. These are the Labour Force Surveys, carried out in the most of developed countries. In the Italian Labour Force Survey (RTFL) the Italian Statistical Institute (ISTAT) quarterly collects information on health-related sick absence, part-time job and unemployment. Data from RTFL of two Italian regions (Lombardy: 1985, '86, '89 and Veneto: 1985, '86) show differentials by age and job-position that are consistent with expectation, encouraging an extensive use of this source for surveillance purposes at the national and regional level.

Absenteeism↗
PubMed1995

[Cholelithiasis and diabetes].

The occurrence rate of diabetes was analyzed in 3370 consecutive patients admitted and surgically treated for biliary lithiasis at the I Department of Surgery-University of Rome "La Sapienza"-between 1959 and 1993. The incidence of such association was found to be overlapping with that of normal population. The natural history and the outcome of patients surgically treated for biliary lithiasis do not seem to be burdened by a concurrent diabetes. Diabetes was in turn found to be correlated with a more frequent presence of stones in the biliary tract. Possible causes of this correlation are discussed. The need in these patients of a more accurate diagnostic approach and specific therapeutic solutions is stressed.

Adult↗
PubMed1995

[Mirizzi syndrome. Diagnostic and therapeutic considerations on 27 cases].

Mirizzi's syndrome is characterized by compression and/or stenosis of the common bile duct as a consequence of a stone impaction in the cystic duct or in the gallbladder neck. Clinical outcome, diagnostic pathway and operative management in 27 patients are presented. Ultrasound is referred as the first screening method, while E.R.C.P. and/or percutaneous transhepatic cholangiography allow to confirm the diagnosis. Surgical approach is considered to be of choice and technical expedients are suggested to prevent intraoperative damage and to repair defects of the common bile duct.

Adult↗