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Biomedical subjects

A Merlo

Publications and source records attributed to A Merlo.

At least 55 records · Page 3Linked to original sources
PubMed1996

Molecular detection of primary bladder cancer by microsatellite analysis.

Microsatellite DNA markers have been widely used as a tool for the detection of loss of heterozygosity and genomic instability in primary tumors. In a blinded study, urine samples from 25 patients with suspicious bladder lesions that had been identified cystoscopically were analyzed by this molecular method and by conventional cytology. Microsatellite changes matching those in the tumor were detected in the urine sediment of 19 of the 20 patients (95 percent) who were diagnosed with bladder cancer, whereas urine cytology detected cancer cells in 9 of 18 (50 percent) of the samples. These results suggest that microsatellite analysis, which in principle can be performed at about one-third the cost of cytology, may be a useful addition to current screening methods for detecting bladder cancer.

Adult↗
PubMed1996

Multidrug chemotherapy in the treatment of non-elderly patients with hormone-refractory prostatic carcinoma. A phase II study. North-Eastern Italian Oncology Group (GOCCNE).

OBJECTIVE: The effectiveness of a chemotherapy regimen including cisplatin, epirubicin, and estramustine phosphate was evaluated in a series of young patients with prostate cancer. METHODS: 28 patients with a histological diagnosis of prostatic carcinoma, age < 70 years, performance status (PS) < 2, hormone-refractory status, life expectancy > 3 months, were treated with cisplatin 60 mg/m2 i.v. and epirubicin 60 mg/m2 i.v. every 3 weeks for six cycles. Estramustine phosphate was administered at a dosage of 10 mg/kg p.o. in two divided daily doses during intravenous chemotherapy and until progression thereafter. The response was assessed after three cycles of chemotherapy, evaluating again the disease parameters. In case of partial remission or stable disease, treatment was continued for three additional cycles. The median age was 61.5 years, the median PS was 70. RESULTS: 11 partial remissions, 13 patients with stable disease, and 4 progressions were noted. The response rate (only partial remissions) was 39% (95% confidence limits 21-57%). The median duration of the partial remissions) was 11 (range 6-25) months. A subjective improvement of symptoms was observed in 17 of 19 patients. Toxicity was acceptable with no deaths. The median overall survival was 15 months. CONCLUSIONS: The combination studied had activity in young prostate cancer patients, and our results suggest that this subset of patients needs specifically devised chemotherapy regimens.

Antibiotics, Antineoplastic↗
PubMed1996

[Effect of magnetic fields on skin wound healing. Experimental study].

Although there are many publications on the usefulness of magneto-therapy, discrepancies exist about the utility of electromagnetic fields in skin wound healing. The objective of this work was to study the effect of electromagnetic fields on wound healing in rats. Thirty six male Wistar rats were used; a rectangular lesion was made in the back of each animal (4.2 cm x 2.3 cm). They were divided into 3 groups: group C (control) with sham treatment; group C50, treated with continuous electromagnetic fields of 5 mT (50 Gauss) and group P200, treated with pulsed electromagnetic fields of 20 mT (200 G). The treatments were of 30 minutes a day during 21 days. The corporal weights (Table 1) and the wound longitudinal and transversal maximal axis (Figures 1, 2) were weekly recorded and the data was evaluated by analysis of variance. On day 14, the P200 group showed the maximal longitudinal axis which was smaller than that of group C (p < 0.01). On day 21 in both treated groups the maximal longitudinal axis was smaller than that of group C (p < 0.01); besides the axis was smaller in the P200 group than in the C50 group (p < 0.05). No statistical differences were observed in the remaining data. The results showed a facilitating effect of electromagnetic fields on wound healing in rats. Pulsed electromagnetic fields seem to have a precocious and larger healing effect than continuous electromagnetic fields.

Animals↗
PubMed1995

Multiple mechanisms of p16INK4A inactivation in non-small cell lung cancer cell lines.

p16INK4A, a specific inhibitor of cyclin-dependent kinase (cdk)4 and cdk6, is a candidate tumor suppressor in malignancies with wild-type retinoblastoma (Rb). Loss of p16INK4A frees these cdks from inhibition, permitting constitutive phosphorylation of Rb and inactivation of its growth suppressive properties. Consistent with this model, Rb-positive non-small cell lung cancers (NSCLCs) have little or no detectable p16INK4A protein, whereas Rb-negative lung cancers have abundant p16INK4A. However, only some NSCLCs have homozygous deletions or nonsense mutations in a remaining p16INK4A allele, suggesting that other mechanisms must account for absent or low levels of p16INK4A protein. Here, we analyzed 9 Rb-positive NSCLC cell lines for the controls governing p16INK4A activity. Four lines had homozygous deletions of p16INK4A (SK-LU-1, SK-MES-1, A-427, and SW900), and three had a point mutation in a single allele. First, in H520 cells, the previously reported deletion at codon 45 results in a frameshift that produces no detectable protein. Second, in Calu-3 cells, a His to Tyr substitution at codon 83 produced a variant with a shortened half-life that was unable to form complexes with cdk4 or cdk6. Third, in H661 cells, the previously reported point mutation in the second intron splice donor site resulted in a smaller p16INK4A protein. Although this variant formed complexes with cdk4 and cdk6, it had a profoundly reduced half-life, producing low steady-state levels of p16INK4A and abundant levels of free cdks. Finally, Calu-1 and Calu-6 cells transcribed no detectable mRNA encoding authentic p16INK4A. These cell lines displayed methylation of the CpG island surrounding the first exon of p16INK4A and expressed abundant levels of a nontranslated mRNA containing an alternative first exon (E1 beta), as did all other cell lines in which the p16INK4A locus was not deleted. These data indicate that Rb-positive NSCLC cells have evolved a variety of pathways to suppress p16INK4A expression. Reintroduction of p16INK4A into these cell lines by retroviral transfer resulted in a reduced growth rate, increased abundance of hypophosphorylated Rb, accumulation of cells in G1, and a less transformed morphology in Rb-positive, but not Rb-negative cells, suggesting that loss of p16INK4A is essential for maintenance of the transformed phenotype.

Carcinoma, Non-Small-Cell Lung↗
PubMed1995

Inactivation of the CDKN2/p16/MTS1 gene is frequently associated with aberrant DNA methylation in all common human cancers.

The tumor suppressor gene CDKN2/p16/MTS1, located on chromosome 9p21, is frequently inactivated in many human cancers through homozygous deletion. Recently, we have reported another pathway of inactivation that involves loss of transcription associated with de novo methylation of a 5' CpG island of CDKN2/p16 in lung cancers, gliomas, and head and neck squamous cell carcinomas. We now show that this aberrant CpG island methylation also occurs frequently in cell lines of breast cancer (33%), prostate cancer (60%), renal cancer (23%), and colon cancer (92%) and is associated with loss of transcription. Primary tumors of the breast (31%) and colon (40%) also displayed de novo methylation of this CpG island. This alteration of p16 in colon cancer was particularly striking, since inactivation does not occur through homozygous deletion in this tumor type. Our data show that in tumors, de novo methylation of the 5' CpG island is a frequent mode of inactivation of CDKN2/p16 and also firmly demonstrate that CDKN2/p16 is one of the most frequently altered genes in human neoplasia.

Carrier Proteins↗
PubMed1995

A novel p16INK4A transcript.

p16INK4A and p15INK4B were initially identified as potent inhibitors of activated cyclin/cyclin-dependent kinase complexes. These genes were colocalized to chromosome 9p21, and p16 was subsequently found to be mutated in familial melanoma and deleted in a wide variety of sporadic cancers. We recently found that de novo methylation of a 5' CpG island led to transcriptional block of full-length p16 in many neoplasms. However, the presence of a truncated p16 transcript in methylated cell lines led us to investigate the presence of an alternative promoter or initiation site. We have now identified an abundant alternative p16 transcript in both methylated and unmethylated cell lines generated from a novel sequence (exon 1 beta) potentially involved in the complex regulation of these critical cell cycle genes.

Base Sequence↗
PubMed1995

Frequency of homozygous deletion at p16/CDKN2 in primary human tumours.

Many tumour types have been reported to have deletion of 9p21 (refs 1-6). A candidate target suppressor gene, p16 (p16INK4a/MTS-1/CDKN2), was recently identified within the commonly deleted region in tumour cell lines. An increasing and sometimes conflicting body of data has accumulated regarding the frequency of homozygous deletion and the importance of p16 in primary tumours. We tested 545 primary tumours by microsatellite analysis with existing and newly cloned markers around the p16 locus. We have now found that small homozygous deletions represent the predominant mechanism of inactivation at 9p21 in bladder tumours and are present in other tumour types, including breast and prostate cancer. Moreover, fine mapping of these deletions implicates a 170 kb minimal region that includes p16 and excludes p15.

Blotting, Southern↗
PubMed1995

5' CpG island methylation is associated with transcriptional silencing of the tumour suppressor p16/CDKN2/MTS1 in human cancers.

Loss of heterozygosity on chromosome 9p21 is one of the most frequent genetic alterations identified in human cancer. The rate of point mutations of p16, a candidate suppressor gene of this area, is low in most primary tumours with allelic loss of 9p21. Monosomic cell lines with structurally unaltered p16 show methylation of the 5' CpG island of p16. This distinct methylation pattern was associated with a complete transcriptional block that was reversible upon treatment with 5-deoxyazacytidine. Moreover, de novo methylation of the 5' CpG island of p16 was also found in approximately 20% of different primary neoplasms, but not in normal tissues, potentially representing a common pathway of tumour suppressor gene inactivation in human cancers.

5-Methylcytosine↗
PubMed1994

[Tumor-immune system interaction in renal cell carcinoma and melanomas. Cytokine transcription in tumors at the time of surgical resection].

Tumor infiltrating lymphocytes (TIL) of many tumors express surface activation markers. An antigen driven stimulation of T-lymphocytes is expected to induce not only cell membrane activation molecules but also a unique pattern of cytokine gene transcripts. These cytokines are relevant modulators and potent effectors of immune responses, and therefore play a crucial role in tumor-immune system interaction. The gene transcription of interleukin(IL)-2, IL-4, IL-7, IL-10 and interferon(IFN)-gamma of lymphocyte infiltrated, freshly excised tumor specimens from 10 renal cell carcinomas and 6 melanomas were investigated by reverse polymerase chain reaction (PCR) technique. Autologous, peripheral mononuclear cells (PBMC) and healthy tissue of the affected organs served as controls. In all samples the transcription of the beta-actin gene as a methodological control turned out to be positive. In contrast, no cytokine gene transcription was detected in healthy tissue specimens and PBMC. IL-2 transcripts were detectable in no melanomas but in half of the renal tumor samples. IL-10 never transcribed in melanomas but was positive in 7 out of 10 renal cell carcinomas. In only 2 respectively 1 of the resected tissue probes was transcription of IL-4 and IFN-gamma detected. IL-7 was positive in 1 melanoma and in 6 urological neoplasias. The most impressive fact is the frequent transcription of the inhibiting factor IL-10 in renal cell carcinomas (7/10). This pattern of cytokine gene transcription may explain functional deficits of TIL.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Homozygous deletion on chromosome 9p and loss of heterozygosity on 9q, 6p, and 6q in primary human small cell lung cancer.

We analyzed the pattern of allelic loss in 33 primary human small cell lung cancers (SCLCs) using highly informative microsatellite markers on chromosomes 2p, 3p, 5q, 6, 9, 13q, and 17p. Nineteen of these tumors (58%) displayed loss of heterozygosity on chromosome 9. Fourteen SCLCs demonstrated loss of heterozygosity for all informative markers on both chromosomal arms; two tumors demonstrated partial loss on chromosome 9p. In one tumor, a multiplex polymerase chain reaction assay disclosed a homozygous deletion at 9p21-22 including the markers IFN-alpha, D9S126, and D9S171. Two SCLCs retained all informative markers on 9p but showed allelic loss of the entire 9q arm, while one case had a partial loss of proximal 9q extending into all of 9p. Analysis of other chromosomal arms showed loss of heterozygosity on 3p (93%), 5q (75%), 6p (46%), 6q (47%), 13q (75%), and 17p (93%). It was necessary to test multiple markers at several loci because of the frequent expression of microsatellite instability that confounded our mapping efforts in SCLCs with replication errors. This study demonstrates the frequent loss of a suppressor gene locus on chromosome 9p21-22 and identifies novel suppressor loci on 6p, 6q, and 9q in primary SCLC.

Adult↗
PubMed1994

Frequent microsatellite instability in primary small cell lung cancer.

Alterations in microsatellite sequences characterize hereditary nonpolyposis colorectal cancer. This microsatellite instability is due in some kindreds to a germline mutation of the mismatch repair gene hMSH2 on chromosome 2p. Although microsatellite alterations have been reported in other hereditary nonpolyposis colorectal cancer-associated tumors including endometrial and gastric cancers, such changes were not detected in most other major neoplasms. We found that 15 of 33 (45%) primary small cell lung cancers, tumors not found in the hereditary nonpolyposis colorectal cancer syndrome, displayed alterations of microsatellite loci which consisted of deletions or expansions of (CA)n dinucleotide repeats. In 8 of these 15 neoplasms, microsatellite instability was detected in more than 10% of all tested alleles. However, small cell lung cancers that revealed instability contained widespread allelic loss and had a uniformly poor prognosis. These results expand considerably the known spectrum of tumors with microsatellite instability.

Adult↗
PubMed1994

[The results of percutaneous diskectomy. The course of pain, work capacity and therapy failure].

In a prospective study extending from November 1989 to December 1992 percutaneous discectomy was carried out in 50 patients (26 men, 24 women, mean age 41 [19-73] years). The aim of the study was to ascertain the efficacy of this new mode of treatment, and its indications. The patients selected for the procedure had chronic, therapy-resistant lumboradicular pain syndrome of at least six weeks' duration; imaging procedure had to show a "bulging disc" and neurological deficits had to be no more than minor. During the subsequent follow up period of 22 +/- 9.6 months 35 of the 50 patients did not require any further surgery; 24 of them (69%) resumed full work while seven (20%) regained partial (50%) working capacity. However, the operation proved ineffective in four of these 35 patients (11%). Fourteen of the 50 patients (28%) had persistent pain and required revision by open classical discectomy; seven of them resumed full work and one regained 50% working capacity. The most frequent findings at this revision were stenosis of the subarticular recess in combination with persistent forward bulging of the longitudinal ligament and anulus fibrosus (n = 7), calcification of the posterior longitudinal ligament (n = 1) and an intervertebral disc sequestrum which gave a false negative results on discography (n = 2). In another case there was a genuine recurrence 35 months after a successful percutaneous procedure; this was treated successfully by open operation. When performed at the level L5/S1, the procedure gave unsatisfactory results in five out of six cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Frequent loss of chromosome 9 in human primary non-small cell lung cancer.

We analyzed the pattern of allelic loss on chromosome 9 in 40 primary human non-small cell lung cancers including 16 squamous cell, 18 adeno-, and 6 large cell carcinomas. Using 24 polymorphic microsatellite markers spanning chromosome 9, we found that 27 of 40 (67.5%) of these neoplasms displayed loss of heterozygosity (LOH) on chromosome 9. Most tumors showed LOH for all informative markers on both chromosomal arms, whereas five tumors demonstrated partial LOH on chromosome 9. In four of these tumors, allelic loss was limited to the 9p arm, whereas in the remaining specimen, LOH extended from 9p21-22 to terminal 9q. These five tumors delineate a minimal area of loss at 9p21-22, which includes a previously defined tumor suppressor gene locus. We have identified a distinct region of loss on chromosome 9p commonly involved in non-small cell lung cancer tumorigenesis.

Aged↗
PubMed1993

Cytokine gene transcription in renal cell carcinoma.

Cytokines are powerful modulators of immune responses, the local production of which could be relevant to the interaction between tumour and immune system. This study investigated the transcription of genes encoding interleukin (IL) 2, IL-4, IL-10 and interferon (IFN) gamma in lymphocyte-infiltrated renal cell carcinoma biopsies from ten patients using the reverse polymerase chain reaction technique. Autologous peripheral blood mononuclear cells and healthy renal parenchyma tissue were tested in parallel. The beta-actin gene, used as a positive control, was transcribed in all samples. In contrast, transcription of cytokine genes was confined to tumour biopsies: IL-2 gene transcripts were detectable in five biopsies and IL-10 transcripts in seven. IL-4 and IFN-gamma gene transcripts were detectable in one biopsy each. In two patients no cytokine gene transcription could be identified. These data underline that heterogeneous patterns of cytokine gene transcription can be observed in renal cell carcinoma biopsies. Although transcription of an immunostimulatory lymphokine such as IL-2 was observed in 50 per cent of biopsies, the most frequently transcribed cytokine gene coded for an inhibitory factor, IL-10.

Aged↗
PubMed1993

Autotraction versus passive traction: an open controlled study in lumbar disc herniation.

Autotraction (AT) is a treatment for low-back pain syndrome of benign etiology that uses a specially designed traction table divided into two movable sections. While lying on the table, the pelvis secured, the patient controls the traction forces by grasping and pulling the bars at the head of the table. There are controls for the therapist to apply, through movable sections of the table, rotation and bending forces to help restore mobility to the lumbar spine without inducing pain. The present study is based upon a randomized treatment trial comparing conventional passive traction (PT) to AT. The following outcome indicators were used: (1) subjective response concerning overall improvement, (2) pain intensity (visual analog scale, 0-100), (3) qualitative pain severity (McGill Pain Questionnaire, short-form, 0-45), and (4) pain related disability (Oswestry Low Back Pain Disability Score, 0-100). The favorable response to AT was 75% (30 of the 40 patients) versus the 22% (6 of 27 patients) to PT (p < 0.001). After 3 months, 19 of the 30 responders to AT (63%) reported continued improvement. In these patients, pain ratings remained stable and the disability scores decreased to 0 to 23% of the pretreatment value (median and mean respectively, p < 0.001).

Adult↗
PubMed1993

Cytokine gene expression in primary brain tumours, metastases and meningiomas suggests specific transcription patterns.

To obtain an insight into the network of cytokine gene transcription in the brain tumour microenvironment, we investigated the expression of genes encoding for interleukin (IL)-1 alpha, IL-1 beta, IL-2, IL-4, IL-5, IL-6, IL-10, interferon (IFN)-gamma, granulocyte-macrophage colony-stimulating factor, tumour necrosis factor (TNF)-alpha and transforming growth factor (TGF)-beta 1, -beta 2 and -beta 3 in freshly excised brain tumour samples and autologous peripheral blood mononuclear cells. Tissue specimens from 15 primary brain tumours, three brain metastases, five meningiomas, autologous peripheral blood mononuclear cells (PBMC) and three brain tumour cell lines were tested by reverse polymerase chain reaction. Despite the presence of T-lymphocytes, cytokine gene transcripts typically detectable upon T cell receptor triggering could not be observed in central nervous system tumours of diverse histology. In primary brain neoplasms, transcription of genes encoding for the inhibitory cytokines TGF-beta and IL-10 was detectable in more than 50% of samples. IL-6 transcripts could only be detected in malignant gliomas. In brain metastases, virtually no cytokine gene transcripts could be observed. Surprisingly, TGF-beta transcripts were also detected in all meningiomas. Thus, transcription of genes encoding for inhibitory factors appears to prevail in primary brain neoplasms.

Adolescent↗