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Biomedical subjects

A Greco

Publications and source records attributed to A Greco.

At least 127 records · Page 7Linked to original sources
PubMed1990

Gadodiamide injection: nonionic gadolinium chelate for MR imaging of the brain and spine--phase II-III clinical trial.

Seventy-three patients with clinically suspected central nervous system abnormalities (44 intracranial, 29 medullospinal) were studied with magnetic resonance (MR) imaging before and after administration of nonionic gadodiamide injection. MR imaging showed intracranial lesions in 37 patients. Eight patients had spinal tumors, and 21 had disk disease. Structural abnormalities were shown in 37 of 44 head studies and in all 29 spine studies. Lesions enhancement was seen in 31 head studies and 28 spine studies, and distinction of lesion(s) from associated edema was possible in 10 head studies and in one study of intrinsic cord tumor. Administration of gadodiamide injection provided improved definition of lesion borders in 19 of 44 head studies and 26 of 29 spine studies. The use of the contrast agent changed the diagnosis that was based on the unenhanced images in nine head studies and 13 spine studies. Early postcontrast, T1-weighted spin-echo images of postoperative spines were adequate in distinguishing epidural scar (enhancing) from herniated disk (nonenhancing). The contrast agent was well tolerated, and no drug-related adverse events occurred.

Adolescent↗
PubMed1990

Development of an interfacility transport program for critically ill cardiovascular patients.

The expanding use of newer coronary artery intervention modalities in the treatment of critically ill cardiac patients has produced a profound change in the manner in which acute care is rendered to these patients. To meet the needs of community hospitals and to improve the safety of interfacility transport to tertiary care centers, a transport program was developed at The Hospital of the Good Samaritan, Los Angeles, California. Rapid transport by helicopter, fixed-wing aircraft or specialized ground ambulance services has been used to improve patient transit time and safety of transfer between the community hospital and tertiary care facility. Experience at The Hospital of the Good Samaritan (1,012 consecutive patients) compares favorably with other programs and proves to be safe and beneficial.

Coronary Disease↗
PubMed1990

Enalapril in the treatment of hypertension associated with renal failure: results from a multicenter study.

Forty-eight hypertensive patients affected by various levels of renal failure entered this open, non controlled study, lasting 12 weeks. Patients were divided into two groups according to baseline creatinine clearance: Group I (29 patients): creatinine clearance greater than or equal to 25 ml/min but less than 45 ml/min; Group II (19 patients): creatinine clearance greater than or equal to 10 ml/min but less than 25 ml/min. Patients in Group I started with enalapril 5 mg q.d. and patients in Group II with enalapril 2.5 mg q.d. Enalapril could be titrated up to 20 mg/day. At the end of the study in both groups of patients blood pressure normalization was reached in a high percentage of patients without any significant change in renal function parameters. Plasma potassium showed a significant increase during the study but no patient discontinued treatment due to hyperkaliemia. In conclusion this study shows antihypertensive therapy with enalapril during chronic renal insufficiency to be effective at low dosage (5-10 mg) in lowering blood pressure and to have a good safety profile.

Adult↗
PubMed1990

[Importance of CA-50 detection in malignant gynecologic tumors].

The role of Tumor Associated Antigens in the diagnosis of neoplasia is now actively investigated. The CA-50 antigen is known to be elevated in different types of gynecological neoplasia. In this study the CA-50 levels have been measured in 70 patients with ovarian, endometrial or cervical cancer. The data obtained show that the CA-50 levels, although elevated above normal in a high percentage of the patients studied, cannot be considered diagnostic for the presence of neoplasia.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1990

Treatment of cancer anorexia with megestrol acetate: impact on quality of life.

The quality of life of patients with advanced cancer depends to a large degree on the presence of disease or treatment-related symptoms. Anorexia is frequent in cancer patients, but has received less attention than other symptoms such as pain or nausea. Yet, anorexia is important because it reduces caloric intake and leads to malnutrition. Further, lack of appetite can disrupt basic activities of daily living, such as eating, and may also interfere with family and social interactions. To test the efficacy of drugs that reverse anorexia, we need accurate and reliable parameters to quantitate this symptom. The effects of anorexia and its reversal on the patients' clinical progress, food intake, nutritional status, and quality of life need to be evaluated. Our ongoing studies demonstrate that megestrol acetate can reverse cancer anorexia and that appetite changes strongly correlate with changes in weight, food intake, and quality of life scores.

Anorexia↗
PubMed1990

The role of magnetic resonance imaging in an oncology centre.

Magnetic resonance (MR) imaging represents the growth area in radiology at present and for well into the 1990s. It has already established itself as the major emerging technique in neuroradiology. Its apparent risk-free application, noninvasiveness and patient comfort provide wide acceptability. This technique may play an important role in the evaluation of cancer patients. Experience with nearly 2,000 patients over a 32-month period demonstrates MR imaging to allow both a more accurate definition of tumor outline and tumor staging, thanks to its high soft-tissue contrast and multiplanar acquisitions. Moreover, MR imaging proves a valuable procedure for radiation treatment planning. Even though it is beyond realistic expectations to seek complete tissue characterization, MR imaging is likely to be increasingly demanded. With the use of specific paramagnetic contrast agents, this technique will eventually replace computer tomography (CT) in both staging and follow-up of several types of cancer.

Bone Neoplasms↗
PubMed1989

Immunohistochemical localization of secretogranin II in the rat cerebellum.

Secretogranin II (chromogranin C) is a peptide related to chromogranin A and secretogranin I (chromogranin B) which is secreted by a regulated pathway from both neurons and endocrine cells. In the present study we have determined by light microscopic immunocytochemistry its distribution in the cerebellum and in adjacent brain stem regions. Secretogranin II was found to be widely distributed throughout the gray matter of these regions. Highly immunoreactive structures in the cerebellar cortex included the majority of climbing fibers, a large number of mossy fibers, sparse varicose fibers in the molecular layer and a subpopulation of neuronal perikarya in the granule cell layer. The location and shape of these neurons are very similar to those of a novel type of cerebellar neurons which has been recently described. A moderate level of immunoreactivity was observed on fibers travelling among Purkinje cells and parallel to the pial surface in the Purkinje cell layer. A variable, but in general low, degree of immunoreactivity was also detectable in the perikarya of Purkinje cells. In the deep cerebellar nuclei a loose network of secretogranin II-positive fibers was visible. Neurons of the nuclei, however, were non-immunoreactive. A dense network of highly immunoreactive fibers was found throughout the brain stem regions adjacent to the cerebellum. Our results indicate that secretogranin II has in the cerebellum and adjacent regions a distribution more widespread than that of known regulatory peptides and suggest that the peptide-mediated signaling in the cerebellum plays a role more important that has been acknowledged so far.

Animals↗
PubMed1989

Chromosomal localization of human genes required for G1 progression in mammalian cells.

Specific probes derived from the human genes that complement the mutations of two independent temperature-sensitive (ts) mutants of the BHK-21 hamster cell line were used to determine the chromosomal locations of the loci in the human genome. The ts11 gene, which complements a mutation that blocks progression through the G1 phase of the cell cycle and which has now been identified as the structural gene for asparagine synthetase, is a member of a small gene/pseudogene family with four members. In a rodent-human somatic cell hybrid panel, the ts11 genomic locus from which the genomic probe derives segregates with human chromosome region 7cen----7q35, proximal to the TCR beta locus. In situ hybridization maps this locus more precisely to the q21-31 region of chromosome 7. Two other members of the gene family detected by the ts11 probe segregate concordantly with chromosome region 8pter----8q24 and chromosome region 21pter----21q22. Similar experiments using the same rodent-human hybrid panel conducted with a probe identifying the tsBN51 gene, which also encodes a function necessary for G1 progression, mapped this locus to human chromosome 8, proximal to the large amplification unit encompassing the c-myc gene of Colo320 cells. Chromosomal in situ hybridization of the tsBN51 probe confirmed the localization of this gene to chromosome 8, with the most likely location of the gene being 8q21.

Animals↗
PubMed1989

Staging of carcinoma of the uterine cervix: MRI-surgical correlation.

Forty-six patients with carcinoma of the uterine cervix were examined with spin-echo magnetic resonance imaging (MRI) using a superconducting magnet operating at a field strength of 0.5 T. All subjects later underwent lymphadenectomy and, when appropriate, radical hysterectomy. Surgical-pathologic correlation was carried out in order to assess the accuracy of the imaging modality in the staging of the disease. In the detection of nodal involvement, the accuracy of MR was 76%. The accuracy in determination of tumour size approached 100%. In the assessment of parametrial and vaginal involvement, the accuracy was 85% and 100% respectively.

Adenocarcinoma↗
PubMed1989

Magnetic resonance imaging in head and neck cancer.

The scans of 120 patients with proven head and neck cancer who underwent magnetic resonance imaging (MRI) at Mt. Vernon hospital were reviewed and, where possible, compared with their clinical, computed tomography (CT) and histological findings. MRI was generally superior to both clinical examination and CT in the detection of cervical lymphadenopathy and in the assessment of primary tumour extent, particularly in the tongue base, nasopharynx and parotid gland. Small intracranial tumour extensions were more readily detected by MRI than CT. MRI was no better than CT in distinguishing between malignant and inflamed tissues and was generally inferior to CT in spatial resolution, patient acceptance and examination cost.

Head and Neck Neoplasms↗
PubMed1989

Organization and expression of the cell cycle gene, ts11, that encodes asparagine synthetase.

The human ts11 gene was isolated on the basis of its ability to complement the mutation of the BHK cell cycle ts11 mutant, which is blocked in G1 at the nonpermissive temperature. This gene has now been identified as the structural gene for asparagine synthetase (AS) on the bases of sequence homology and the ability of exogenous asparagine to bypass the ts11 block. The ts11 (AS) mRNA has a size of about 2 kilobases and is induced in mid-G1 phase in human, mouse, and hamster cell lines. We have studied the organization and regulation of expression of the ts11 gene. The human ts11 gene consists of 13 exons (the first two noncoding) interspersed in a region of about 21 kilobases of DNA. Transient expression assays using the bacterial chloramphenicol acetyltransferase reporter gene identified two separate promoters: one (ts11 P1) contained in a 280-base-pair region upstream of the first exon and the other (ts11 P2) contained in the first intron. ts11 P1 produced about sixfold more chloramphenicol acetyltransferase activity than did ts11 P2 and had features of the promoters of housekeeping genes: high G + C content, multiple transcription start sites, absence of a TATA box, and presence of putative Sp1 binding sites. ts11 P2 contained a TATA sequence and other elements characteristic of a promoter, but so far we have no evidence of its physiological utilization. The ts11 gene was overexpressed in ts11 cells exposed to the nonpermissive temperature. Addition of asparagine to the culture medium led to a drastic decrease in mRNA levels and prevented G1 induction in serum-stimulated cells, which indicated that expression of the AS gene is regulated by a mechanism of end product inhibition.

Asparagine↗
PubMed1989

'Benign thoracic pain' syndrome: role of magnetic resonance imaging in the detection and localization of thoracic disc disease.

The syndrome of 'benign thoracic pain' is seen in young women who have pain and tenderness in the mid-thoracic spine radiating around the chest and aggravated by spinal movement. Ten consecutive patients with this syndrome and 15 controls were evaluated with magnetic resonance imaging (MRI). This showed thoracic intervertebral disc dehydration with no associated prolapse in 90% of the patients and 13% of the controls. We postulate that the clinical features are due to impaired shock absorption of these degenerate discs rather than direct compression of surrounding structures. MRI is non-invasive and does not use ionizing radiation; it allows direct visualization of the entire thoracic spine and cord, and accurate detection of early disc degeneration. Thus, it is the imaging modality of choice for defining the subtle intervertebral disc abnormalities that characterize the 'benign thoracic pain' syndrome.

Adult↗
PubMed1988

Analysis of RAS oncogene mutations in human lymphoid malignancies.

We investigated the frequency of mutations activating RAS oncogenes in human lymphoid malignancies, including B- and T-cell-derived acute lymphoblastic leukemia, chronic lymphocytic leukemia, and non-Hodgkin lymphoma. By the polymerase chain reaction/oligonucleotide hybridization method, DNA from 178 cases was analyzed for activating mutations involving codons 12 and 61 of the HRAS, KRAS and NRAS genes and codon 13 of the NRAS gene. Mutations involving codons 12 or 13 of the NRAS gene were detected in 6 of 33 cases of acute lymphoblastic leukemia (6/33, 18%), whereas no mutations were found in non-Hodgkin lymphoma or chronic lymphocytic leukemia. Direct nucleotide sequence analysis of polymerase chain reaction products showed that the mutations involved a G----A transition in five of the six cases of acute lymphocytic leukemia. In four cases the mutations seemed to occur in only a fraction of the neoplastic cells, and one case displayed two distinct NRAS mutations, most likely present in two distinct cell populations. These results indicate the following: (i) RAS oncogenes are not found in all types of human malignancies, (ii) significant differences in the frequency of RAS mutations can be found among subtypes of neoplasms derived from the same tissue, (iii) in lymphoid neoplasms the NRAS mutation correlates with the most undifferentiated acute lymphocytic leukemia phenotype, and (iv) NRAS mutations present in only a fraction of malignant cells may result from either the selective loss or the acquisition of mutated alleles during tumor development.

Animals↗
PubMed1988

Randomized phase II evaluation of iproplatin (CHIP) and carboplatin (CBDCA) in lung cancer. A Southeastern Cancer Study Group trial.

Cisplatin-containing regimens have shown activity in both small and non-small cell lung cancer. We therefore conducted a randomized Phase II trial of the new platinum congeners iproplatin and carboplatin in bronchogenic carcinoma. The overall response rate in chemotherapy-naive non-small cell patients with iproplatin was 3/48 (6%; 95% confidence interval 2-18%) and with carboplatin 6/50 (12%; 95% confidence interval 5-25%). The response rates in previously treated small cell patients were 0/16 and 1/18, respectively. Overall, neither agent has pronounced activity in bronchogenic carcinoma.

Adult↗
PubMed1988

Cyclosporin neurotoxicity in cardiac transplant recipients.

Cyclosporin toxicity may produce a wide range of neurological disorders. We report three patients whose neurological problems developed while taking cyclosporin following cardiac transplantation, but resolved rapidly when the drug was discontinued. In two cases, MRI revealed abnormalities which disappeared with clinical recovery. Blood cyclosporin concentrations were not markedly increased, and it is possible that the neurotoxic effects of cyclosporin are mediated by metabolites, through an effect on the blood-brain barrier.

Adolescent↗