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L Colombo

Publications and source records attributed to L Colombo.

At least 19 recordsLinked to original sources
PubMed1992

Cloning and sequencing of European sea bass (Dicentrarchus labrax L.) growth hormone cDNA using polymerase chain reaction and degenerate oligonucleotides.

To clone and sequence the cDNA of the growth hormone of European sea bass (Dicentrarchus labrax L.) (sbGH), total pituitary RNA was reverse transcribed and amplified using polymerase chain reaction (PCR). Degenerate oligonucleotides, designed by comparing available GH cDNA sequences from related teleost species, were used as primers to amplify the 5' end and the core region of sbGH cDNA, while the 3' end was amplified according to the Rapid Amplification of cDNA ends (RACE) method. SbGH cDNA contains an open reading frame encoding a preprotein of 204 amino acids. The deduced amino acid sequence shows a putative signal peptide of 17 amino acids, suggesting that the mature hormone consists of 187 amino acids. Sequence comparison indicates a high degree of conservation of GH cDNAs within the Percoidei infraorder. Our procedure based on degenerate oligonucleotides and PCR provides a straightforward approach to clone GH cDNAs from other related bony fishes.

Amino Acid Sequence↗
PubMed1992

Indomethacin-induced enteropathy: effect of the drug regimen on intestinal permeability in rats.

To set up and characterize reproducible, long-standing small intestinal inflammation in rats, animals were given three different oral regimens of indomethacin (Ind): a bolus of 10 mg/kg in water and three daily doses of 2, 4, and 8 mg/kg Ind in (a) the drinking water or (b) the standard diet. The effect of Ind on the small intestine was monitored by measuring intestinal permeability (IP). The three-day regimen seemed more suitable than a bolus dose to induce long-standing inflammatory modifications in the rat small intestine and Ind administered in the drinking water gave more consistent modifications of IP and more reproducible results than Ind in food. IP seemed a suitable tool for detecting these inflammatory changes in the small-intestinal physiology. This model could be used to assess the effect of new drugs on inflammation.

Administration, Oral↗
PubMed1992

[Changes in lipid status during pravastatin treatment].

Reduced cholesterolemia lowers the risk of ischemic cardiopathy, especially if LDL cholesterol levels are reduced. Today this effect can be achieved using drugs following the discovery of a new class of molecules: statins are specific inhibitors of HMG-CoA-reductase, a key enzyme in cholesterol biosynthesis. These molecules act by modifying the intracellular quota of cholesterol, especially at a hepatocytic level, thus enabling an enhanced expression of those genes responsible for forming receptors for membrane LDL with an increased number of receptors. This leads to a modulation of receptor activity which interferes with LDL uptake, promoting more rapid clearance. The aim of this study was to confirm the efficacy and tolerability of pravastatin when used for long periods in patients with high cholesterol levels, and to compare its activity to that of gemfibrozil.

Cholesterol↗
PubMed1992

[Asymptomatic aortic dissection associated with a mitral prosthetic leak: a clinical case report].

A case of aortic dissection ("DeBakey type III") in an asymptomatic 78-year-old woman is described. The patient underwent a mitral valve replacement (bioprosthesis Sorin) in June 1990 for severe mitral stenosis; in October 1990 she was admitted to our hospital for severe dyspnea and cardiac failure with good response to medical treatment. The routine echo color Doppler examination showed only a hint of paraprosthetic leak, which required further investigation by transesophageal echocardiography. This approach revealed the presence of a regurgitant jet extending from the prosthetic mitral valve toward the atrial septum. The examination of the thoracic aorta revealed the presence of a dissection flap; the color Doppler technique showed a bidirectional flow through the site of communication between the two lumina. The extension of the dissection from the aortic arch to the origin of the renal branches was confirmed by computerized axial tomography. We emphasize the importance of the transesophageal approach in elderly patients with aortic dissection, often asymptomatic.

Aged↗
PubMed1991

[Changes in morning platelet aggregation in patients with peripheral obliterating arteriopathy after evening administration of picotamide].

Platelets are involved in the progressive pathogenesis of atherosclerosis. It has been shown that there is usually an increase in platelet aggregation between 6 and 9 a.m.; in the present study. in 10 patients suffering from chronic occlusive arterial disease, the impedancemetric method was used to evaluate, in whole blood, platelet aggregation induced by ADP and collagen the day prior to and the day following the evening administration of 300 mg picotamide. Analysis of the data obtained shows, in accordance with the findings of other authors, in increase of platelet aggregation from 6 a.m. to 9 a.m. This increase is suppressed by the evening administration of the anti-aggregant.

Aged↗
PubMed1991

Antibiotic GE2270 a: a novel inhibitor of bacterial protein synthesis. II. Structure elucidation.

GE2270 A, produced by Planobispora rosea ATCC 53773, inhibits Gram-positive bacteria and anaerobes by acting on the bacterial protein synthesis. The structure has been determined by physico-chemical methods applied to the intact molecule and to the main hydrolysis products. Characterization by UV, IR, NMR (double quantum filter COSY), acid-base ionization, elemental analysis and FAB-MS indicated that GE2270 A is a highly modified peptide having MW 1,289 and formula C56H55N15O10S6, and a weak basic function, and that it belongs to the thiazolyl peptide group of antibiotics. Acid hydrolysis yielded a main product (MW 634), responsible for the chromophoric absorption, and a number of hydrolyzed products of lower MW. 13C NMR inverse techniques and MS studies (EI, positive ion chemical ionization, and collision induced dissociation FAB-MS-MS experiments) on GE2270 A, the chromophoric compound, and the other hydrolysis products led to the complete identification of the various amino acid residues and their sequence. Two out of the six chiral centers have been determined. The structure is thought to originate from modification of a chain of 14 amino acids in a process which creates 6 thiazole rings and one pyridine. The modification process also closes the linear polypeptide to form a cyclic part with an attached side-chain. GE2270 A plausibly has a similar biosynthetic origin to that of other thiazolyl peptide antibiotics such as nosiheptide and micrococcin.

Actinomycetales↗
PubMed1990

Therapeutic possibilities of 131I-MIBG in metastatic carcinoid tumors--preliminary report.

The poor results of traditional therapy in advanced carcinoid tumors and the well-proven uptake of 131I-MIBG shown by some of these tumors induced us to attempt a radiometabolic approach. We selected for the treatment 5 patients (3 men and 2 women) who showed progression of disease, a fairly good uptake of 131I-MIBG with severe related symptoms, and a poor response to traditional therapy. A cumulative radioactivity of 5.5-29.6 GBq was given. Acute side effects after 131I-MIBG administration or late radiation-induced damages were not observed. Symptoms increased during the first 2-4 weeks in 2 patients: in one of these relief was achieved with drugs. Results concerning objective remission of the disease were unsatisfactory. In contrast, definite improvement of symptoms was shown in 2 of 5 patients, resulting in a better quality of life.

3-Iodobenzylguanidine↗
PubMed1990

Sertoli and Leydig cell numbers and gonadotropin receptors in rat testis from birth to puberty.

In testes of rats from 2 to 60 days of age, we examined the number of Sertoli cells (SC) and Leydig cells (LC) as well as the binding of radioiodinated gonadotropins to frozen sections and homogenates. The number of SC per testis increased only during the first 2 postnatal weeks, whereas that of LC was stable up to days 7-10 and increased thereafter. The uptake of 125I-labelled human follicle-stimulating hormone (125I-FSH) to frozen sections was confined to sex cords or seminiferous tubules, while that of 125I-labelled human choriogonadotropin (125I-hCG) matched the distribution of LC in the interstitium. High affinity receptors for FSH and hCG were found in homogenates at all stages studied. The number of FSH receptors per testis increased steadily, whereas that of hCG receptors was low until days 7-10 and rose afterwards. Thus, SC in rat testis appear to proliferate in the presence of fetal LC during the first 2 postnatal weeks and to differentiate concomitantly with the emergence of the adult LC generation after day 10. The complement of FSH receptors in SC remains constant as they proliferate and increases after day 21 as they differentiate. The hCG receptor number is relatively fixed in each LC generation, being higher in adult compared to fetal LC.

Aging↗
PubMed1990

Effects of word- and sentence-level contexts upon word recognition.

In the present experiments, we investigated the facilitatory effects of auditorily presented prime words in neutral sentence contexts upon visually presented target words. It is shown that when the target task is a lexical decision, facilitation is obtained when the relationship between the prime and the target is one of synonymy (and low association strength). When instead the target is an antonym (again of low association strength), there is no priming effect; lexical decision is facilitated only when the prime word is presented in isolation. In further experiments, it is shown that primes in sentence contexts can produce facilitation of antonyms if they are strongly associated, or in the absence of association if the target must be named. The results are explained in terms of an integration process, which checks for the coherence between an upcoming word and the highest available level of representation of the context, but which affects only responses in the lexical decision task.

Attention↗
PubMed1990

[Evaluation of the efficacy and safety of pravastatin in primary hypercholesterolemia].

Hypercholesterolemia can be a risk factor which engenders coronary heart disease. Today, it seems certain that lowering the cholesterolemia reduces this risk, especially if this reduction is referred to the cholesterol which is linked to the low density lipoprotein, called LDL. It has been demonstrated that the principle way to remove the LDL is by getting it into the hepatocyte through a specific membrane receptor, the research, therefore, has been developed with the aim of pharmacologically modifying the quota of intercellular cholesterol and consequently, in the modulation of the receptivity function by the interference of the LDL uptake, assisting a faster clearance. We can identify a new class of pharmacological drugs, that are the specific inhibitors of the HMGCoA reductase, fundamental enzime in the biosynthesis of cholesterol. This group of inhibitors has recently been enriched by the addition of a new molecule pravastatin. Our task has been to confirm the effectiveness and tolerability of pravastatin, administered for a prolonged period to patients with high levels of cholesterolemia; we have compared it with gemfibrozil, a well-known medicine which has hypocholesterolemic effects. In conclusion, our work, whilst emphasising the expediency of ipolipidic treatment, has undoubtedly proved, that 40 mg of pravastatin in a single evening dose, shows a high degree of efficiency, without side effects. Due to these factors, we can also say that pravastatin prevents, or really induces the regression, of atheroscherotic disease.

Anticholesteremic Agents↗
PubMed1990

[Brodie's syndrome].

The authors, after having completed a wide bibliographic research on this subject, examine the etiopathogenesis of Brodie's syndrome, and distinguish a congenital from an acquired form. The different therapeutic possibilities, orthodontic or surgical, have been examined and discussed.

Adolescent↗
PubMed1989

[Immunoregulation of tumor growth in a murine model].

Different spleen and tumor cell factors modifying tumoral and metastatic growth were studied. Spleen cell culture supernatants (SCS) from small and large tumor-bearing mice enhanced tumor growth. After tumor surgery, tumor enhancement was only mediated by supernatants from large tumor resected mice. Tumor facilitation and angiogenic response were mediated by the same supernatants; different fractions for these two activities were characterized. T and non-T cells, depending on tumor burden, were responsible for the enhancing activity; but angiogenesis depended only on T cells. While augmentation of metastatic spread was produced by tumor antigens (soluble tumor extracts, tumor-cell supernatants, formolized tumor cells), primary tumor development was not modified by tumor-cell supernatants. Increased incidence of metastases was also mediated by SCS from tumor resected mice which had previously been inoculated with tumor antigens. Immune status of tumor-resected mice was evaluated by delayed-type hypersensitivity reaction. Tumor cell membranes enriched with cholesterol-hemisuccinate were able to increase anti-tumor immune response.

Adenocarcinoma↗
PubMed1979

In vitro binding of radioiodinated rat follicle-stimulating hormone to the testis of the mallard duck, Anas platyrhynchos l.

The binding of 125I-labelled rat FSH to homogenates and frozen sections of mallard duck testis was investigated. The equilibrium association constant (Ka) in the homogenates (8.5 x 10(9) M-1) was similar to those reported in other avian and mammalian species. Autoradiography suggested that the binding sites for the labelled hormone were localized in the tubular compartment.

Animals↗
PubMed1978

[Acupuncture in the treatment of neuralgic syndromes of the facial region. Methodological studies and evaluation of the clinical results].

The A. present their experiences in the therapy of 274 facial neuralgias treated by acupuncture at the department of Oral Surgery of the University of Turin Medical School, between September 1973 and June 1976. The problems of a precise diagnosis and a research on the methods of treatment and statistical evaluation of the clinical results are presented with particular interest to the relation between acupuncture treatment and drug therapy.

Acupuncture Therapy↗