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Biomedical subjects

P Colombo

Publications and source records attributed to P Colombo.

At least 127 records · Page 7Linked to original sources
PubMed1993

Gastric retention of sucralfate gel and suspension in upper gastrointestinal diseases.

This study was designed to compare by scintigraphy the gastric retention of a new dosage form of sucralfate as gel (Gastrogel) with that of sucralfate suspension in 25 patients with upper gastrointestinal symptoms referred for routine endoscopy. After endoscopy 4 subgroups were defined: macroscopically normal mucosa (n = 7), antral gastritis and/or erosions (n = 6), gastric ulcer (n = 6) and duodenal ulcer (n = 6). Each patient received either sucralfate gel or sucralfate suspension in equivalent doses (5 ml containing 1 g sucralfate). Both formulations were labelled with 111 MBq 99mTc-DTPA before administration. The mean value of t1/2 in the total group was significantly longer when patients were taking sucralfate gel (61.6 min) compared to sucralfate suspension (33.8 min) (P < 0.001). The mean values of t1/2 were significantly longer for sucralfate gel compared to sucralfate suspension also among the subgroups (macroscopically normal P < 0.02, antral gastritis P < 0.05, gastric ulcer P < 0.02 and duodenal ulcer P < 0.05). After 2 and 3 hours, the percentage residual activity in the gastric area was significantly higher following administration of sucralfate gel compared to sucralfate suspension. This study has shown that, compared to sucralfate suspension, sucralfate gel persists longer in the stomach of patients with gastritis and peptic ulcer.

Adolescent↗
PubMed1992

Conservation of the organization of five tightly clustered genes over 600 million years of divergent evolution.

The organization of the mouse surfeit locus is unusual in that it contains six housekeeping genes (Surf-1-Surf-6), which are unrelated by sequence homology, in the tightest mammalian gene cluster thus far described. A maximum of only 73 base pairs separates any two of the four well-characterized genes, and two of the genes overlap at their 3' ends. The direction of transcription of each of the five surfeit genes, Surf-1-Surf-5, alternates with respect to that of its neighbor, suggesting cis-interaction or coregulation between the genes by mechanisms such as the sharing of regulatory elements and/or antisense regulation. The Surf-3 gene has been identified as encoding the ribosomal protein L7a (Rpl7a). We have used the high conservation of the Rpl7a gene to clone the chicken gene and surrounding genomic DNA. The tight clustering and juxtaposition of at least five of the surfeit genes (Surf-1-Surf-5) and their associated CpG-rich islands have been found to be conserved over the 600 million years of divergent evolution that separates birds and mammals. This strongly suggests that the surfeit locus represents a different form of gene cluster in which gene organization may play both a positive and negative regulatory role in gene expression possibly via cis-interactions between the closely spaced genes.

Amino Acid Sequence↗
PubMed1992

Functional elements of the ribosomal protein L7a (rpL7a) gene promoter region and their conservation between mammals and birds.

The transcriptional initiation sites of the chicken ribosomal protein L7a (rpL7a) gene have been determined and found to occur at three consecutive cytidine residues at the start of a polypyrimidine tract of 8 base pairs (bp). A comparative analysis of the 5' upstream regions of the mouse, human and chicken rpL7a genes identified two sequence elements (Box A and Box B) conserved over the 600 million years of divergent evolution that separate mammals and birds. Only Box A (nts - 56 to - 39) and Box B (nts - 25 to - 4) sequences were detected to bind nuclear factors from mouse nuclear extracts in an analysis of the mouse rpL7a 5' upstream sequence. Box A and Box B bind different nuclear factors and the factor binding to mouse Box A and mouse Box B sequences could be effectively competed by corresponding homologous sequences from the human and chicken rpL7a promoters. These results indicate that elements of the rpL7a promoter region are conserved between mammals and birds. An in vivo analysis of the mouse rpL7a 5' upstream sequence required for efficient transcription identified the 5' border of the minimal promoter region as lying between nts - 50 and - 56. Constructs containing 56 bp of 5' upstream DNA and the first 25 bp rpL7a exon were very efficiently transcribed indicating that sequences within the first intron are not required for gene expression. No sequence similarity was detected between the rpL7a promoter elements and described promoter elements of other eukaryotic ribosomal protein genes.

Animals↗
PubMed1992

The silent corticotropinoma: is clinical diagnosis possible?

Up to now, the diagnosis of silent corticotroph cell pituitary adenomas has been made only on histopathological basis. In this paper we describe 6 women affected with pituitary adenomas, without evident clinical features of hypercortisolism, in whom retrospective data suggested the possibility of clinically diagnosing silent corticotropinomas in vivo. In all patients basal ACTH and cortisol levels were normal, and the low-dose dexamethasone test constantly suppressed serum cortisol and urinary 17-hydroxycorticosteroid levels. The CRH and/or lysine-vasopressin tests, performed in five patients, always induced exaggerated ACTH/cortisol rises. In three cases the response to the opiate agonist loperamide was assessed and no inhibition of ACTH/cortisol levels was found. All patients underwent pituitary surgery. In five cases evidence of corticotropinoma was obtained by immunohistochemistry or immunofluorescence studies; moreover, in one adenoma ACTH was secreted into the culture medium, and in another one CRH and arginine-vasopressin induced a marked intracellular [Ca++] rise. Electron microscopy study of the adenoma, removed from three patients, showed the presence of adenomatous corticotroph cells. Finally, in another woman no hormonal abnormalities were initially observed and she was operated for a "nonfunctioning" pituitary adenoma, but four years later an overt Cushing's disease appeared, suggesting that a silent corticotropinoma subsequently became functional, although the formation of a different adenoma cannot be excluded. In conclusion, the occurrence of ACTH/cortisol hyperresponsiveness to CRH and/or lysine-vasopressin and the lack of suppression of ACTH/cortisol secretion to opioid agonists in patients with apparently "nonfunctioning" pituitary tumors might allow the in vivo recognition of silent corticotropinomas.

17-Hydroxycorticosteroids↗
PubMed1992

Prevalence of hepatitis C infection in a hemodialysis unit.

To define the prevalence of NANB hepatitis, anti-HCV antibodies were determined in 51 patients on renal replacement therapy, in 7 transplanted patients and 17 staff members of the hemodialysis unit. Anti-HCV antibodies were evaluated using immunoenzymatic methods (Ortho HCV ELISA Test System, 1st and 2nd generation). Among hemodialysis patients, seroconversion was respectively documented in 17.6% (9/51) and 52.9% (27/51); none of the transplanted patients were positive with the 1st generation test, while 3/7 were positive with the 2nd. No statistically significant difference was found in the prevalence antibodies between transfused and nontransfused patients. ALT levels were statistically greater in patients with anti-HCV antibodies (X2 2nd generation = 8.83; p less than 0.01). Our results suggest: (1) that hemodialysis represents a risk factor; (2) the validity of substitute markers and (3) more sensitivity of the 2nd than 1st generation test.

Adult↗
PubMed1992

[A case of multiple deformities: upper harelip, tubercles of the auricle, anus in vulva].

The case presented of a newborn with multiple deformities: preauricular tubercles, left auricular roof deformity, labicachisis of the right upper lip, dermoid-type swelling on the left eye, deep labial fold at the left commissure and "forked" anus in vulva. Though the combination does not exactly match any syndrome, it has various points in common with Goldenhar's syndrome, of which it might be a phenotype variant. The single cause of the malformations might be an early (microvascular) disturbance of the primary segments in growth areas surrounding the cephalic and caudal segments, first of the medullary plate and subsequently of the primary medullary canal.

Anal Canal↗
PubMed1992

Risk factors for mortality from lower respiratory infections in nursing home patients.

BACKGROUND: Little is known about the factors that predict whether nursing home residents with lower respiratory infection (LRI) will do well or poorly, although this information is critically important when making treatment decisions. METHODS: Using nursing home and hospital medical records, we performed a case-control study to identify risk factors for death from LRI among residents of a 110-bed, midwestern community nursing home. Three experienced geriatricians aided in the development of an operational definition of an LRI. In a 3 1/2-year period, we identified 26 cases in which the patients died from LRI and 66 control episodes in which the patients recovered from LRI. RESULTS: Compared with those who survived, those who died were 14 times more likely to be totally dependent with respect to activities of daily living (ADL) than the group of patients least ALD-dependent (odds ratio [OR] = 14; 95% confidence interval [95% CI] = 2.85 to 68.87). After adjusting for ADL, mortality was significantly decreased when a broad-spectrum oral antibiotic (trimethoprim-sulfamethoxazole, cefaclor, amoxicillin-clavulanate, or ciprofloxacin) was used as the initial therapy (OR = .14; 95% CI = .02 to .81). CONCLUSIONS: Better functional status and initial therapy with broad-spectrum oral antibiotics were strong predictors of surviving an LRI in this population of nursing home patients. The antibiotic effect may be a treatment effect or the consequence of underlying factors leading physicians to select particular antibiotics; however, it appears possible to identify low-risk persons who do not require the aggressive treatment and hospitalization that is often recommended for these patients. An approach to the treatment of nursing home LRI is suggested.

Activities of Daily Living↗
PubMed1992

Bone marrow harvest for marrow transplantation: effect of multiple small (2 ml) or large (20 ml) aspirates.

The aim of this study was to evaluate the yield of nucleated cells and CFU-GM and the T cell composition in bone marrow harvested by means of multiple small (2 ml) or large (20 ml) aspirations. Eleven marrow donors were studied: each donated 1000 ml of bone marrow in two aliquots of 500 ml for an HLA identical sibling transplant. In six cases the first 500 ml were harvested by means of multiple 2 ml aspirations (A) and the second 500 ml by means of 20 ml aspirations (B). In five cases the opposite was done: 20 ml aspirates first (C) and 2 ml afterwards (D). From each 500 ml aliquot a sample was taken for enumeration of nucleated cells and CD3+ lymphocytes and for CFU-GM growth. Small volume aspirations (groups A and D) yielded more nucleated cells (p = 0.02), more CFU-GM (p = 0.03) and fewer CD3+ cells (p = 0.1) when compared with large volume aspirations (groups B and C). This study shows that marrow harvesting by means of multiple small volume aspirations minimizes the dilution with peripheral blood and results in greater numbers of cells and hemopoietic progenitors.

Adult↗
PubMed1991

The organization and expression of the human L7a ribosomal protein gene.

The genomic structure and sequence of the human ribosomal protein L7a (rpL7a) and its transcriptional start sites have been determined. The gene contains eight exons and seven introns spread over 3179 bp. The human rpL7a gene is similar to other mammalian ribosomal protein genes in containing a short first exon, a short 5' untranslated leader and its transcriptional start sites at C residues embedded in a polypyrimidine tract. The 25 bp polypyrimidine tract containing the two human rpL7a start sites is the longest polypyrimide tract so far observed for a mammalian ribosomal protein gene.

Base Sequence↗
PubMed1991

Smouldering hepatitis B virus replication in patients with chronic liver disease and hepatitis delta virus superinfection.

Hepatitis B virus deoxyribonucleic acid (HBV-DNA) was studied by Southern blot analysis in liver biopsy specimens from 75 HBsAg-positive patients with chronic liver disease living in southern Italy. Twenty-seven of the patients were hepatitis delta virus (HDV) superinfected. Intrahepatic HBV-DNA was detected in 54 (72%) patients, 32 (59%) of them with replicative forms. The presence of replicative forms was directly related to liver HBcAg and inversely related to liver HDAg, as shown by multivariate analysis. However, 14 patients with intrahepatic HBV-DNA non-replicative pattern and about half of HDV-infected patients were liver HBcAg and/or serum HBV-DNA positive, mostly in low amounts. Histological inflammatory activity was strongly related to liver HBcAg expression regardless of HDV superinfection, as confirmed by multivariate analysis. Our results confirm previous studies about the concordance between intrahepatic HBV-DNA replicative pattern and liver HBcAg expression and about inhibition by HDV of high-level HBV replication. However, they suggest that low-level HBV replication may have an important role in causing liver damage also among HDV-infected patients, in a population where the spreading of HBV and HDV is a naturally occurring event.

Adolescent↗
PubMed1991

[Evaluation of the analgesic activity of a new ketoprofen-sucralfate combination].

The Authors reported a therapeutic antalgic trial carried out on 50 patients, affected with head-ache, tooth-ache, menstrual pain, muscular and rheumatic pains. They were treated with tablets with ketoprofen covered by sucralfate compared with ASA tamponed tablets for 6 days. Results show that the therapeutic activity of the two drugs is substantially the same, but ketoprofen with sucralfate gastroprotection reports a very good tolerability.

Adolescent↗
PubMed1991

[Hernias of the abdominal wall in old age].

Following a review of the literature on the topic, the authors examined all patients admitted to the Institute of Surgical Pathology 1st at the University of Pavia between 1-1-1974 and 31-12-1988 affected by hernias of the abdominal wall or surgical laparoceles, paying special attention to those patients aged over 65. Attention was focused on concomitant diseases, the acuteness of the basic pathology and possible recurrence. From the results obtained it was concluded that the associated pathology and the acute state of the basic diseases condition the successful outcome of the operation more than age itself. For this reason, it is important that patients affected by these pathologies are operated as soon as possible in order to carry out an elective operation which reduces postoperative complications and reduces the risk of recurrence.

Acute Disease↗
PubMed1990

1,2-Dichloropropane (DCP) toxicity is correlated with DCP-induced glutathione (GSH) depletion and is modulated by factors affecting intracellular GSH.

Acute 1,2-dichloropropane (DCP) poisoning in humans is relatively frequent in Italy, where DCP is widely diffused as a constituent of commercial solvents and dry cleaners. In this study we have investigated the effects of DCP on intracellular glutathione (GSH) content in main target tissues of male Wistar rats, i.e. liver, kidney and blood, in order to establish if a correlation between DCP-induced GSH depletion and tissue damage exists. Administration of DCP (2 ml/kg body weight orally) caused a dramatic loss of tissue GSH occurring 24 h after DCP intoxication, followed by a slow restoration approaching physiological levels after 96 h. GSH depletion was associated with a marked increase in serum GOT, GPT, 5'-nucleotidase, gamma-glutamyl transpeptidase, alkaline phosphatase, urea and creatinine, and a significant degree of hemolysis. When animals were pretreated with a GSH depleting agent, buthionine-sulfoximine (BSO) (0.5 g/kg body weight) i.p. 4 h before DCP intoxication, an increase of overall mortality was found, significantly different from the group of animals treated with DCP alone. On the contrary, the administration of a GSH precursor, N-acetylcysteine (NAC) i.p. (250 mg/kg body weight) 2 and 16 h after DCCP intoxication prevented the dramatic loss of cellular GSH and reduced the extent of injury in target tissues, as demonstrated by laboratory indices. Furthermore, statistical analysis of the data revealed a correlation between: (1) depletion of liver GSH and increase in serum GOT, GPT, 5'-nucleotidase, (2) depletion of kidney GSH and increase in serum urea and creatinine and (3) depletion of blood GSH and the occurrence of hemolysis.(ABSTRACT TRUNCATED AT 250 WORDS)

5'-Nucleotidase↗