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Biomedical subjects

L Serra

Publications and source records attributed to L Serra.

At least 73 records · Page 4Linked to original sources
PubMed1991

The role of epidermal growth factor in the pathogenesis of peptic ulcer disease.

Duodenal biopsies obtained from seven normal subjects and six ulcerous patients were cultured in vitro for 30 min at 37 degrees C under various experimental conditions. Epidermal growth factor (EGF) and somatostatin released in the culture medium were determined by radioimmunoassay. Under basal conditions, EGF and somatostatin levels were significantly higher in normal subjects (11.49 +/- 3.07 ng/mg protein and 3.06 +/- 0.8 ng/mg protein, respectively) than in ulcerous patients (6.9 +/- 1.98 ng/mg protein and 1.75 +/- 1.23 ng/mg protein, respectively). However, when antibodies to somatostatin and vasoactive intestinal polypeptide (VIP) were added together to the culture media, in ulcerous patients, EGF levels also were lower as absolute values, but were higher as a percentage of variation than controls (p less than 0.05). The fall of EGF secretion from tissue cultures of ulcerous patients could be the consequence of endocrine cellular loss or damage, rather than the cause of ulceration. Moreover, the EGF-producing cells around the lesion in ulcerous patients seems to be hyperactive, and this hyperfunction of EGF-producing cells might contribute to the in vivo repair of tissue damage.

Adult↗
PubMed1990

Role of vasoactive intestinal polypeptide (VIP) and endogenous somatostatin on the secretion of epidermal growth factor (EGF): studies on duodenal tissue cultures.

Epidermal Growth Factor (EGF)-containing cells have been found in Brunner's glands in the same area where several regulatory peptides are released. The present study was aimed at testing the release and the regulation of EGF secretion from cultured duodenal biopsies obtained from healthy individuals by gastroscopy. The effects and the interaction of VIP and somatostatin on the hormone release were studied. Duodenal biopsies were cultured at 37 degrees C in Mc Coy's buffer, gassed with 95% O2 and 5% CO2. After 30 min, the culture medium was decanted for the measurement of the hormones by RIA. To measure the protein content, the tissue was then homogenized; EGF detected in the culture was 11.5 ng/mg protein. The addition of VIP in the medium increased EGF mean levels to 21.6 ng/mg protein (P less than 0.01). The biopsies thus obtained were cultured with anti-somatostatin antibodies to evaluate the influence of endogenous somatostatin on EGF secretion. The inclusion of anti-somatostatin antibodies increased the EGF levels to 41.2 ng/mg protein (P less than 0.01). The combined addition of anti-somatostatin antibodies and VIP in the culture caused a mean EGF increase significantly higher than the values obtained separately by VIP and somatostatin (P less than 0.01). In conclusion, we can suggest a triangular interaction model of EGF release, where the somatostatin seems to be the negative monitor of over-secreted VIP and EGF from the gut.

Adult↗
PubMed1990

Seroepidemiology of measles in Catalonia (Spain) 1985-1986.

A seroepidemiological study of measles immunological status was carried out among four different populations: schoolchildren of 6-7 years, 10-11 years and 13-14 years, and pregnant women of 18-45 years, in Catalonia, Spain; 1,213 children and 239 pregnant women were surveyed. The measurement of measles antibodies were made by indirect immunofluorescence, with antibody titres greater than or equal to 1:8 considered as positive. The prevalence of measles antibodies was 82.9% in the 6-7 year old group, 87.2% in the 10-11 year old group and 94.4% in the age group 13-14 years. Among pregnant women, the prevalence of antibodies was 96.2%. Two of the variables studied were associated with the prevalence of measles antibodies in schoolchildren: the disease antecedents and measles vaccination. In pregnant women aged 18-45 no variable had any statistically significant association with the prevalence of measles antibodies.

Adolescent↗
PubMed1988

Colonization of America by Drosophila subobscura: Experiment in natural populations that supports the adaptive role of chromosomal-inversion polymorphism.

North America and South America have recently been colonized by the Palearctic species Drosophila subobscura. This double colonization offers a rare opportunity for evolutionary studies. Correlations between chromosomal arrangement frequencies and latitude were calculated for the colonizing populations. Signs of these correlations are highly coincident with those found in the Old World. These results provide experimental support for the adaptive value of the chromosomal-inversion polymorphism; historical and other nonadaptive explanations are thus excluded or relegated to a secondary role.

Journal Article↗
PubMed1988

The induction phase of neuromuscular block after suxamethonium and pancuronium: analysis of the time constant of single-twitch decay (tau T1).

The T1% (first unconditioned stimulus of train-of-four) decay was analysed in 55 patients paralysed with different doses of suxamethonium and pancuronium during minor elective ear and nose surgery. In patients given pancuronium, T1% decay is well described by a mono-exponential function: a semi-log plot of ln(T1%) versus time is in fact a straight line. Predicted values are quite comparable with mean and individual values recorded in patients. From these equations the time-constant of single-twitch decay, or tau T1, may be calculated easily: it is a good dynamic descriptor of the speed of onset of neuromuscular block. In patients paralysed with suxamethonium, the rapidly developing block makes it difficult to acquire a sufficient number of data for computation of regression lines: while T1% seems to decrease exponentially, as in the pancuronium groups, no definite conclusions are possible at present. The authors conclude that tau T1 may be a useful dynamic descriptor of neuromuscular block induced by non-depolarizing muscular blocking drugs. Two new concepts are introduced: (i) the time spent to overcome the 'margin of safety' of neuromuscular transmission, or T MOS; and (ii) the speed index, as a measure of the relative speed of the onset of block.

Action Potentials↗
PubMed1987

Analysis of microdifferentiation in a Spanish cellar population of Drosophila melanogaster.

Variation in Adh and alpha Gpdh-1 gene frequencies has been used to check for microdifferentiation in Spanish samples of Drosophila melanogaster inside and outside a wine cellar. Flies were collected after vintage and after overwintering respectively; within each period samples were taken on up to five consecutive days each month. Variation of gene frequencies of Adh and alpha Gpdh-1 can be considered random when samples collected each month are taken into account. When mean monthly frequencies are considered, alpha Gpdh-1 does not show any significant variation all over the year; yet, variation of the frequency of AdhS shows a cyclical pattern, its frequency being maximum at the end of the summer and minimum after overwintering. Due to the parallel change of the frequency of the inversion In(2L)t and the AdhS allele, no decision can be made whether the Adh locus itself or the inversion are responsible for the changes.

Alcohol Dehydrogenase↗
PubMed1986

Childhood non-Hodgkin's lymphoma and "leukemia-lymphoma syndrome": long-term results with the modified LSA2-L2 protocol.

From June 1976 to December 1984, 48 previously untreated children with non-Hodgkin's lymphoma (NHL) were treated according to the LSA2-L2 protocol, modified by inclusion of cranial irradiation for patients in stage III and stage IV disease. According to the staging system proposed by Wollner, 4 patients were in stage I, 8 in stage II, 11 in stage III, 8 in stage IVA (less than or equal to 25% blasts in the bone marrow), 15 in stage IVB (greater than 25% blasts in the bone marrow), and 2 in stage IV central nervous system disease. The complete remission rate was 95.8%. The relapse-free survival (RFS) rate of 46 complete responders was 76% after a median observation time of 47+ months. Only 1 of 35 high-risk responder patients developed CNS relapse after prophylactic treatment. Clinical stages were related to the RFS: 100% in stage I-II vs. 69% in stage III-IV. All 8 patients in stage IV were alive without evidence of disease with a median observation time of 59+ months. Fifteen patients in stage IVB who had leukemia-lymphoma syndrome attained 59% RFS with a median observation time of 39+ months. After a median observation time of 38+ months, 29 of 37 patients are off therapy. The results emphasize the value of both the histologic and immunologic features and the stage of disease in predicting the outcome of NHL in children. The LSA2-L2 regimen appears to be a very effective protocol for children with lymphoblastic lymphoma, although it may be less efficacious for patients with large bone marrow involvement.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1985

Intellectual function in long-term survivors of childhood acute lymphoblastic leukemia.

21 off-therapy ALL patients treated with chemotherapy plus cranial irradiation were assessed using the Wechsler Intelligence Scale for Children and compared with a group of 15 off-therapy solid tumor children treated with chemotherapy and extracranial irradiation. Children with leukemia achieved lower IQ scores than children with solid tumors. The ALL group was divided in two subgroups, by onset of disease and beginning of treatment: before (13 subjects) and after (8 subjects) 5 years of age. The results indicate that the disturbance of intellectual functioning is produced in ALL children irradiated after 5 years of age. In order to check on a possible delayed intellectual deterioration, all ALL children were also tested twice, with one year interval between the two tests. On the second assessment the scores for each subject were essentially the same as before. Further studies on a large number of long term survivors are being carried out in order to find out whether the deficit is transient or permanent.

Age Factors↗
PubMed1984

Transient optic neuropathy secondary to MOPP chemotherapy in Hodgkin's disease: report of a case.

The authors describe a case of optic neuropathy in a child undergoing MOPP chemotherapy for Hodgkin's disease stage IIISA. Visual acuity improved after substitution of the aforementioned regimen with ABVD chemotherapy, and reached 1 during maintenance therapy with vinblastine. Various neurologic deficits have been ascribed to vincristine, a well-known neurotoxin. This case of optic neuropathy is supposed to be a rare example of involvement of the 2nd cranial nerve due to vinca alkaloids. The absence of neurotoxicity of vinblastine in this case is emphasized.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1983

Interactions between neoplastic cells with different metastasizing capacity and platelet function.

We have examined the effects on platelet function of two sublines (M4 and M9) derived from spontaneous lung nodules of a benzopyrene-induced murine fibrosarcoma (m FS6). The subline M4 was more metastatic and the subline M9 less metastatic than the primary tumour. Only the more malignant cells were able to induce irreversible aggregation of human platelets; this effect was concentration-dependent and was associated with the release of serotonin by platelets. Both aggregation and release were inhibited by preincubation of platelets with ASA, not by preincubation of the cells. The supernatants of cell suspensions had no aggregating activity. However, the neoplastic cells in culture media released an activity directly stimulating platelet aggregation and potentiating the platelet response to ADP; again, this activity was higher for the more malignant cells and the effects were inhibited by preincubation of platelets with ASA. These results suggest a role for platelets in the development of tumour metastases.

Adenosine Diphosphate↗
PubMed1982

[In vitro effect of culture fluids from neoplastic tissues on platelet aggregation. I. Human tumors of the gastrointestinal tract].

The effects on platelet function of culture media from 7 human tumours of the gastroenteric tract have been studied on platelet rich plasma obtained from 28 apparently normal subjects. Platelet aggregation was investigated according to Born's method. Some of the culture media showed an aggregating activity on platelets, while others did not; after dialysis, however, also the last ones aggregated platelets. Furthermore all the media both before and after dialysis were able to increase the platelet response to low doses of ADP (3 microM), and these effects were inhibited by Aspirin (0,1 mM). These results suggest that the tumours investigated release stimulating activities on platelet function and that these interactions can be inhibited pharmacologically.

Adenosine Diphosphate↗
PubMed1982

[In vitro effect of culture fluids from neoplastic tissues on platelet aggregation. II. Experimental tumors].

We have investigated the effects on platelet function of culture media from 2 sublines of a benzopyrene-induced murine sarcoma (mFS6). Platelet aggregation was investigated according to Born's method. The cell line with greater "in vivo" invasiveness showed higher aggregating activity and higher increase on ADP-induced aggregation; these effects were inhibited by the preincubation of platelets with Aspirin (0,1 mM). These results suggest the role of platelets in metastasis formation; the possibility to inhibit pharmacologically the interactions between platelets and tumour cells could have important implications from both speculative and practical viewpoints.

Adenosine Diphosphate↗
PubMed1982

Neuroblastoma in a pair of identical twins.

Hereditary neuroblastoma in a pair of identical twins is reported. In one of the twins the tumor occurred in fetal life and caused death of the twin before birth; in the other one, the tumor occurred at two months of life as IV-S neuroblastoma in the liver with primary tumor undetected. The unusual clinical course of the latter case is described: twice there was tumor regression, but in spite of treatment, fatal uncontrolled growth occurred. The family history, characterized by neoplasms of dissimilar cell types but without additional cases of neuroblastoma, is also detailed.

Adrenal Gland Neoplasms↗