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Biomedical subjects

P Barbero

Publications and source records attributed to P Barbero.

At least 37 records · Page 2Linked to original sources
PubMed1998

Pro-neurotensin/neuromedin N expression and processing in human colon cancer cell lines.

The regulatory peptide neurotensin NT has been proposed to exert an autocrine trophic effect on human colon cancers. In the present study, pro-neurotensin/neuromedin N (proNT/NN) expression and processing were investigated in 13 human colon cancer cell lines using a combination of radioimmunoassay and HPLC techniques. All 13 cell lines displayed low to moderate levels of proNT/NN ranging from 10 to 250 fmol/mg protein. However, only 6 (HCT8, LoVo, HT29, C119A, LS174T, and coloDM320) processed the precursor. Three of the latter (HCT8, LS174T, and coloDM320) were analysed in detail with regard to proNT/NN processing pattern and were found to produce NT and large precursor fragments ending with the NT or NN sequence. They had no detectable level of NN. Such a processing pattern resembles that generated by the prohormone convertase PC5. Northern and Western blot analysis of prohormone convertase expression in the 3 cell lines revealed that they were devoid of PC1 and PC2, whereas they all expressed PC5. These data indicate that proNT/NN is a good marker of human colon cancer cell lines while NT is found in only about half of the cell lines. They also suggest that, in addition to NT, several proNT/NN-derived products, possibly generated by PC5, might exert an autocrine positive effect on human colon cancer growth.

Aspartic Acid Endopeptidases↗
PubMed1996

Evidence that PC2 is the endogenous pro-neurotensin convertase in rMTC 6-23 cells and that PC1- and PC2-transfected PC12 cells differentially process pro-neurotensin.

The neuropeptide precursor proneurotensin/neuromedin N (pro-NT/NN) is mainly expressed and differentially processed in the brain and in the small intestine. We showed previously that rMTC 6-23 cells process pro-NT/NN with a pattern similar to brain tissue and increase pro-NT/NN expression in response to dexamethasone, and that PC12 cells also produce pro-NT/NN but are virtually unable to process it. In addition, PC12 cells were reported to be devoid of the prohormone convertases PC1 and PC2. The present study was designed to identify the proprotein convertase(s) (PC) involved in pro-NT/NN processing in rMTC 6-23 cells and to compare PC1- and PC2-transfected PC12 cells for their ability to process pro-NT/NN. rMTC 6-23 cells were devoid of PC1, PC4, and PC5 but expressed furin and PC2. Stable expression of antisense PC2 RNA in rMTC 6-23 cells led to a 90% decrease in PC2 protein levels that correlated with a > 80% reduction of pro-NT/NN processing. PC2 expression was stimulated by dexamethasone in a time- and concentration-dependent manner. Stable PC12/PC2 transfectants processed pro-NT/NN with a pattern similar to that observed in the brain and in rMTC 6-23 cells. In contrast, stable PC12/PC1 transfectants reproduced the pro-NT/NN processing pattern seen in the gut. We conclude that (i) PC2 is the major pro-NT/NN convertase in rMTC 6-23 cells; (ii) its expression is coregulated with that of pro-NT/NN in this cell line; and (iii) PC2 and PC1 differentially process pro-NT/NN with brain and intestinal phenotype, respectively.

Animals↗
PubMed1996

Histological changes in edentulous oral mucosa under implant-supported overdentures.

The microscopic characteristics of the mucosa covering the alveolar ridge that supports a complete denture have long been studied. In this paper, any histological changes in mucosa loaded by a denture before and after a denture has been anchored by implant onto the bone were followed. The results suggest that mechanical loads improve trophism of mucosa, and that fixing a denture to implants leads to a more uniform distribution of loads.

Aged↗
PubMed1996

[The dental assessment of the patient waiting for a liver transplant].

Until the last several years liver transplantation was considered an experimental treatment procedure. Nowadays virtually any disease process, that is in terminal stage, is treatable with transplantation. The introduction of cyclosporine in 1980 and the recent use of OKT3 monoclonal antibody now allows a 5-year survival rate of 60-70%. The causes of early death of patients who survive after surgery are infective complications, multiorgan failure and acute rejection of the allograft. In the literature and in our experience, bacterial sepsis is the most common cause of deaths occurring during the first postoperative months while most deaths after one year are generally related to chronic rejection of the allograft. The risk of infection is also increased by the over-immunosuppression of these patients always treated with a high dose of immunosuppressive agents when evidence of acute graft rejection is found. Regarding these problems, patients being prepared for liver transplantation should be evaluated for their dental health. The medical indications of 80 transplant recipients and the current status of liver transplantation are reviewed in this article. We describe the dental status of these patients that should receive indicated dental care before surgery. Most patients (90%) were affected by chronic active hepatitis while the number of primitive cirrhosis was significantly lower. Very poor dental hygiene was found in 85% of patients while 45% were affected by advanced periodontal disease and 12% by a chronic gingivitis. Dental caries were observed in 67% while in 20% of cases endodontic periapical lesions were found and only 2% of these resulted as radicular cysts. Indicated dental care consisted in 87% of cases in dental hygiene instructions, in 85% in scaling and root planing, in 63% in conservative restorations and in 40% in endodontic treatments. Dental treatment guidelines before transplantation are described with particular attention to prevent risk of infection using antibiotic prophylaxis for invasive dental procedures. Dentists, after surgery must be also prepared to deal with excessive bleeding related to a severe liver disfunction; for this purpose an appropriate protocol is also described. The monitoring of oral and general health conditions and the achievement of specific protocols of prophylaxis are helpful in the prevention of complications and are fundamental to obtain the best results with liver transplantation improving the quality of life of these patients.

Adult↗
PubMed1989

[Hemorrhagic cyst of the mandible. A case presentation].

Haemorrhagic mandibular cysts are quite rare and generally considered sequelae of an earlier trauma causing an overflow of blood into the bone, though a number of pathogenic theories have been put forward. Since few of these cysts involve subjective symptoms, most are discovered accidentally during radiography, while a sure diagnosis is only likely to be obtained during surgery on the discovery of a nonepithelialized cavity. The paper presents a typical case of haemorrhagic mandibular cyst which was treated by opening the cavity and scraping its walls in order to cause bleeding that would promote the growth of new bone tissue.

Adult↗
PubMed1984

[Radioimmunological assay of alpha-fetoprotein in maternal serum and intrauterine fetal growth retardation].

Maternal plasma alpha-fetoprotein (AFP) was measured in fifteen women during first-mid-third-trimester of pregnancy. In three of these pregnacies by means ultrasound was relevable a condition of intrauterine growth retardation (IUGR). AFP was assayed by a double-antibody radioimmunoassay and values were compared with the median value of the normal range for the particular week of pregnancy. Plasma AFP levels were significantly higher in one subject with IUGR than in other patients.

Female↗
PubMed1982

[Radioimmunologic and radioreceptor analysis of human chorionic gonadotropin for the diagnosis and control of ectopic pregnancy].

The authors report here their studies on the use of a radioreceptor assay study of HCG for the diagnosis and management of ectopic pregnancy. Seven blood samples were collected before, during and three days after the surgical intervention; their HCG content was assayed with a radioreceptor method and the results were compared with those of radioimmunological method. The radioreceptor assay, with a sensitivity of 200 mUI/ml, has provided 85% reliability in detecting pregnancy, the radioimmunoassay the 100%. A case of ectopic resorbing pregnancy showed a HCG content of 25 mUI/ml (RIA) and a RRA negative; the low concentration of hcg caused the negativity of RRA, the sensibility of which is too low in this case. A deeper analysis of the technical results shows some possible sources of error.

Chorionic Gonadotropin↗
PubMed1978

10p- syndrome associated with multiple chromosomal abnormalities.

A karyotype with six de novo autosomal abnormalities in chromosomes 2,4,9,10,12, and 13 was identified in a 7-year-old boy with mental retardation and other minor malformations. The G- and C-banding techniques revealed an equilibrated translocation between autosomes 2 and 4 and between autosomes 9 and 13. One chromosome 10 has lost genetic material from its short arms, probably because of an interstitial deletion. An unidentified chromosomal fragment has become inserted in the long arms of an autosome 12. The G bands demonstrate that genetic material inserted in the autosome 12 is not the genetic material deleted from the autosome 10. The propositus presents clinical features similar to the reported cases with 10p- syndrome. Nevertheless it is not possible to establish the influence of the genetic material inserted in autosome 12 on the propositus' phenotype.

Child↗
PubMedDate not supplied

[Alternating hemiplegia in young babies].

INTRODUCTION. This paper review the state of the art of alternating hemiplegia of childhood. This entity is a rare neurologic disorder of infancy characterize by transient hemiplegic spells shifting from one side to another, and occasionally affecting to both hemispheres at the same time. Usually start before 18 months, many cases exhibit neonatal symptoms related with the disorder. Early symptomatology include abnormal ocular movements, mainly nystagmus, and tonic or dystonic attacks generally beginning before 6 months of age. These symptoms are frequently misdiagnosis as epilepsy. Typical hemiplegic fits which disappeared when infant felt asleep appeared by 12 months of age. Diagnosis is on clinical basis after excluding any other causes of fluctuating and transitory hemiplegic attacks. Complementary investigations, such as electroencephalograms, TAC, MRI, angiographic MRI, CFS are strictly normal. Cerebral SPECT show controversial abnormalities in some studies. We perform SPECT study in a alert 12 months old girl during an interictal period resulting in a non significant asymmetry, with lesser perfusion in left frontal basal and anterior temporal gyrus. Nevertheless, we observed an striking hyperperfusion in middle occipital area. Treatment is symptomatic with flunarizine. Our patient experience a dramatic decrease in frequency, duration and severity of hemiplegic attacks.

Brain↗