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Biomedical subjects

A Costa

Publications and source records attributed to A Costa.

586 records · Page 33Linked to original sources
PubMedDate not supplied

Biological prospectives to define prognosis and treatment strategies in liver metastases from colorectal cancer.

Liver metastases arise in about a third of patients with colorectal cancer. Although important clinical results have been obtained by surgical treatment in patients with limited liver involvement, other intra-arterial or systemic therapies do not provide important long term clinical benefits in patients with unresectable liver metastases. Better knowledge of the biology of liver metastases could imply a more appropriate use of the available therapeutic approaches and a retrospective definition the biologic subgroups of patients who benefit from them. Phenotypic and molecular aspects of tumor cells have been investigated and have proven to be important determinants of clinical outcome in patients with different human tumor types. Liver metastases from colorectal cancer have been scarcely studied, but cell proliferation has been shown to be a discriminant of freedom from progression and even more of long-term clinical outcome in subsets in patients treated with radical surgery. Moreover, in patients with resectable liver metastases, DNA and entity of DNA abnormalities are significantly associated with patient survival. A few recent reports have indicated a potential prognostic relevance of abnormal activation or expression of the p53 tumor suppressor gene, bel-2 protein and ras oncogene. In conclusion, prognostic biologic factors are acquiring an important role as indicators of clinical outcome in patients with liver metastases. However, all information is derived from retrospective analyses heterogeneous for patient population and biomarkers analyzed. Therefore, the comparison among results from different studies is difficult, and prospective studies are needed to develop a prognostic classification which integrates biologic and pathologic factors.

Cell Division↗
PubMedDate not supplied

[Sepsis in the very low-birth-weight newborn infant].

Sepsis is a common pathology during the neonatal period. Low-birth weight is the most important isolated risk factor. With the purpose of determining the prevalence of nosocomial infection in newborns of very low birth weight (VLBW), finding the microbial flora and the mortality of these patients, the authors retrospectively analysed the clinical processes of the hospitalized VLBW in the Neonatal Intensive Care Unit (NICU) in S. João Hospital in 1993 and 1994. Of the 1091 newborns admitted to the hospital in these two years, 112 were VLBW (10%). Of these, 48 had sepsis-31 (28%) confirmed sepsis and 17 (15%) probable sepsis. The agents most commonly found were Staphylococcus epidermidis (44%) and Klebsiella pneumoniae (21%). Thirteen patients (27%) died, with infection as the cause of death in nine (19%). Our results confirm the importance of nosocomial neonatal infection, which should involve the strict observance of the asepsis norms and a proper policy of antibiotics.

Anti-Bacterial Agents↗
PubMedDate not supplied

Effect of sodium butyrate on human breast cancer cell lines.

We have investigated the effects exerted by sodium butyrate (NaBu) on the growth and cell cycle perturbations of four human breast cancer cell lines (MCF7, T47D, MDA-MB231 and BT20) with different steroid receptor profiles. Moreover, since one of the supposed mechanisms of action for NaBu activity involves the induction of apoptosis, we have studied the effects of NaBu on DNA fragmentation by agarose gel electrophoresis and flow cytometry. In all investigated cell lines, NaBu exerted a time- and dose-dependent inhibition of growth and caused a maximum inhibitory effect (85% to 90%) at the concentration of 2.5 mM. The inhibition was already evident after 3 days of treatment. The antiproliferative effect of NaBu was associated with a persistent block of cells in the G2M phase. The block was associated with apoptosis only in oestrogen-receptor positive cell lines. The inhibiting effect of NaBu in hormone-dependent and independent cell lines and its ability to induce apoptosis through a cell cycle perturbation in hormone-dependent cell lines may have important implications in the treatment of human tumours including breast cancer.

Antineoplastic Agents↗
PubMedDate not supplied

The effects of physical exercise at high altitude on adrenocortical function in humans.

The combined effects of sustained physical activity and hypoxia on adrenocortical function were investigated in 14 healthy volunteers, 8 males and 6 females (mean age 40.9 +/- 3.3 years), during a scientific expedition in the Himalayas. Plasma cortisol levels were measured in all subjects in basal conditions and after the administration of 1 mg dexamethasone (DXM) p.o. The study was performed before and after 15 days of intense trekking (Leh, altitude 3700 m). While on both occasions subjects retained their cortisol circadian fluctuations, basal and post-DXM cortisol levels at high altitude were significantly higher (p < 0.005 and p < 0.0005) than before climbing. Cortisol suppression was noted in all cases at low altitude, whereas 4 out of the 14 subjects did not show reduced hormone levels after 15 days of trekking. Moreover, nonsuppressor subjects had significantly higher (p < 0.05) baseline cortisol levels than suppressors. Basal and post-DXM hormone levels were found to be unrelated to age and sex of subjects. The present data further suggest that sustained physical activity at altitude activates adrenocortical function in normal individuals; however, in 30% of subjects DXM-induced cortisol suppression does not occur. To explain the latter observation, the concomitant role of hypoxia (and/or other environmental changes) and the subjective perception of physical stressors should be taken into account.

Adrenal Cortex↗
PubMedDate not supplied

Diphenylhydantoin-induced hepatitis: a case report.

This case report is of a 25-year old man with severe diphenylhydantoin-induced hepatitis, fever, rash and generalized lymphadenopathy. Hepatic histology and lymphocyte transformation tests strongly supported the diagnosis. He made an uneventful recovery with supportive therapy.

Adult↗
PubMedDate not supplied

Cluster headache and periodic affective illness: common chronobiological features.

Many of the seasonal changes occurring in animals appear to be associated with photoperiodic modifications, and particularly with the duration of the phases of exposure to light and dark. The integration of these processes is made possible by the normal functioning of biological oscillators or synchronizers, presumably located at the hypothalamic level. Cluster headache (CH), seasonal affective disorder (SAD) and bipolar mood disorders are conditions bearing numerous analogies, particularly as regards the temporal pattern of disturbances, the nature of predisposing or precipitating factors, the peculiar relationship with sleep, the neuroendocrine findings, and the clinical response to current treatments. The secretion of melatonin, which is influenced by the light/dark cycle, displays a bimodal pattern, which is likely to be dictated by the activity of distinct synchronizers for light and dark. Changes in the secretory pattern of this neurohormone have also been documented in both CH and SAD. The possibility of normalizing the secretory rhythm of melatonin by means of phototherapy in SAD, and the therapeutic use of the hormone to prevent the recurrence of active phases in CH, represent further interesting similarities between these two disorders. Melatonin, acting as a unique neuroendocrine transductor of photic inputs, may therefore be viewed as a marker of dyschronic disease to be used in patients suffering from CH and affective illness, for both diagnostic purposes and to assess the response to pharmacological and non pharmacological treatments.

Antidepressive Agents↗