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Biomedical subjects

F Gomez

Publications and source records attributed to F Gomez.

At least 73 records · Page 4Linked to original sources
PubMed1996

[Internet network and cancer].

Internet is a tool allowing a wide distribution of information. Initially reserved to the field of scientific research, it develops currently in many sectors of the socio-economic life and saved the area of the health. Each day appear new services allowing the access to the information on the diagnostic and treatment of different pathologies. Patients and physicians share their knowledge and their information, through newsgroups and electronic mail. This paper presents the Internet and cancer resources to allow clinicians and researchers a rapid access to the relevant information.

Computer Communication Networks↗
PubMed1995

[Endocrinological aspects of hypophyseal tumors].

Local expansion of pituitary tumors causes nonspecific symptoms, including hormone insufficiency, that may exist for years before diagnosis. Although they are more specific, symptoms of pituitary hormone oversecretion may also remain unrecognized and give rise to difficult diagnostic problems. Gonadotropic tumors do not elicit specific endocrine symptoms, whether they secrete complete gonadotropins or their biologically inactive free subunits. Hyperprolactinemia is not due to tumor secretion in the majority of cases, including some with a tumor in the pituitary (compressive hyperprolactinemia). When acromegaly is suspected, the unequivocal proof of excess growth hormone secretion is not easy to obtain, due to intermittent growth hormone secretion, both in normals and in acromegalics. The large variety of tests available for the etiological diagnosis of hypercorticism indicates the diagnostic difficulties that can be encountered. Corticotrope pituitary adenomas may be minute, and ectopic corticotropin secretion may remain occult. But on the other hand, the quality of the diagnostic tools available improves constantly. This includes new hormone measurements, such as insulin-like growth factor 1 and its binding proteins, dynamic tests, selective pituitary blood drawing by inferior petrosal sinus catheterism, pituitary nuclear magnetic resonance imaging and somatostatin-analogue scintiscan. In addition to the improving techniques of transphenoidal neurosurgery and pituitary radiotherapy, medical management of pituitary tumors remains a distinct possibility. Tumor hormone secretion can be controlled in some cases by drugs such as dopaminergic agents, somatostatin analogues and gonadoliberin analogues, which may also exert an antitumoral mass effect. Within the next few years we will be confronted with an increasing number of incidentally discovered pituitary tumors, due to the frequent use of high-resolution intracranial imaging.

Acromegaly↗
PubMed1995

Ischemic stroke in young adults. Experience in 329 patients enrolled in the Iowa Registry of stroke in young adults.

OBJECTIVES: To describe the likely causes of ischemic stroke in a population of young adults and to report the influence of strict algorithms on the diagnosis of the likely cause of stroke in this cohort. DESIGN: Between July 1, 1977, and January 1, 1993, we registered 329 young adults with ischemic stroke in our registry. Diagnostic studies were selected on a case-by-case basis. Presumed causes of stroke were determined using clinical information and the results of diagnostic tests. In each case, a second causative diagnosis was made using the criteria developed for a large clinical trial. SETTING: Patients referred to the Division of Cerebrovascular Diseases in the Department of Neurology at the University of Iowa Hospitals and Clinics, Iowa City, by physicians in Iowa and adjacent states. PATIENTS: Three hundred twenty-nine young adults (182 men and 147 women) aged 15 to 45 years with ischemic stroke; 102 persons, 48 men and 54 women, were aged 30 years or younger. RESULTS: Cerebral arteriography was performed in 227 cases, and the findings were abnormal in 146. Transthoracic echocardiography revealed abnormalities in 82 of 221 patients examined. We identified approximately 60 different disorders that were presumed to be the cause of stroke. There were no major changes in the frequency of subtype diagnoses between the first 144 patients and the subsequent 185. Use of strict diagnostic criteria increased the number of cases of stroke of undetermined etiology (from 45 to 113), and the number attributed to large artery atherosclerosis declined from 71 to 32. CONCLUSIONS: The causes of ischemic stroke in young adults are numerous. Because treatment options in this group are influenced by a presumed cause, an evaluation on a case-by-case basis is warranted. Our experience suggests that a likely cause will be detected in most cases and that a regimented battery of tests may not be required. If strict diagnostic criteria are used, the diagnosis of stroke of undetermined etiology considerably increases. While such strict criteria are important in clinical trials that test new interventions, the value of the application of such methodologies to an unusual population, such as stroke in young adults, needs clarification. In particular, the usefulness of categorizing a stroke as undetermined when two or more possible causes are identified needs to be explored.

Adolescent↗
PubMed1995

Identification of macroprolactin in a patient with asymptomatic hyperprolactinemia as a stable PRL-IgG complex.

We characterize the molecular form of PRL in a female patient with asymptomatic, idiopathic hyperprolactinemia. Size exclusion chromatography revealed that PRL was present exclusively in the form of macroprolactin (> 200 kD mol wt). By immunoaffinity purification, Western blot analysis, and binding studies the molecule was identified as a PRL-IgG complex of extremely high stability. Sequence analysis revealed no mutations in the protein coding region of the hPRL gene using hPRL cDNA amplified from the patient's peripheral blood lymphocytes. In spite of full bioactivity in vitro, as determined by Nb2 bioassay, the complex apparently lacks bioactivity in vivo. Its high molecular weight may reduce its access to target organs in the periphery as well as centrally.

Adult↗
PubMed1995

Ruptured aneurysms of the internal iliac artery. Report of two cases.

Solitary internal iliac artery aneurysms are very rare. Their localisation deep in the pelvis makes diagnosis difficult. Therefore they are not detected until they reach a significant size and produce symptoms. These symptoms are due to compression on the adjacent structures or their rupture. Duplex scan, computerized tomography, and arteriography are the most useful diagnostic procedures. The correct surgical therapy consists of the ligature of the internal iliac artery and endoaneurysmorraphy with obliteration of the tributary branches. We report herein two cases of aneurysms of the internal iliac artery that made their clinical debut with signs of rupture.

Aged↗
PubMed1994

Impaired function of macrophage Fc gamma receptors and bacterial infection in alcoholic cirrhosis.

BACKGROUND: Bacterial infection is a frequent and often fatal complication in patients with cirrhosis. Macrophages play an important part in the host defense against infection because their Fc gamma receptors recognize antibody-coated bacteria. METHODS: We prospectively studied macrophage Fc gamma-receptor function in vivo and in vitro in 49 patients with alcoholic cirrhosis, 10 alcoholics without cirrhosis, and 20 normal volunteers. RESULTS: The clearance of IgG-sensitized autologous red cells was decreased in 37 of the 49 patients with cirrhosis but in none of the subjects without cirrhosis. In the 49 patients clearance was inhibited by a mean (+/- SE) of 47 +/- 3 percent at 1 hour and 53 +/- 3 percent at 1 1/2 hours, as compared with the clearance in the normal controls (P < 0.001). The impairment of macrophage Fc gamma-receptor-dependent clearance correlated with the degree of liver insufficiency but not with age, sex, nutritional status, HLA haplotype, or the presence of circulating immune complexes. The clearance of unsensitized and heat-altered autologous erythrocytes was normal. In vitro recognition of IgG-sensitized red cells by monocytes from the patients was not significantly decreased. During a two-year follow-up period, 11 patients had severe bacterial infections, and in 4 they were fatal. The mean clearance of IgG-sensitized red cells in these 11 patients (half-time, 126.2 +/- 22 hours) was significantly impaired, as compared with that in the 38 patients without severe infection (half-time, 32.2 +/- 18 hours, P < 0.001). CONCLUSIONS: The function of macrophage Fc gamma receptors is impaired in patients with alcoholic cirrhosis, and this impairment probably contributes to the high incidence of bacterial infections among such patients.

Antigen-Antibody Complex↗
PubMed1994

Prognosis of young adults with ischemic stroke. A long-term follow-up study assessing recurrent vascular events and functional outcome in the Iowa Registry of Stroke in Young Adults.

BACKGROUND AND PURPOSE: Information about the long-term prognosis of young adults with ischemic stroke is limited. Therefore, we performed a follow-up assessment of 296 patients with ischemic stroke who are enrolled in the Iowa Registry of Stroke in Young Adults. We studied young adults (age, 15 to 45 years) who were referred to a tertiary medical center for management of ischemic stroke between July 1, 1977, and January 1, 1992. METHODS: Follow-up assessments were performed by means of questionnaires, examinations, telephone interviews, review of medical records, and reports from personal physicians. Data about risk factors, coincident medical diseases, etiology of stroke, treatment, recurrent stroke, other vascular events, and deaths were collected. Outcomes were rated with the Glasgow Outcome Scale, Barthel Index, National Institutes of Health stroke scale, and the Mini-Mental State Examination. Quality of life was assessed with the SF-36 Health Status questionnaire. RESULTS: Follow-up information about the status of 10 patients was limited except that they were alive. Twenty-one patients (7%) died as the result of their initial stroke, and another 40 patients (14%) died during a mean follow-up of 6.0 years. None of the patients aged 25 years or younger at the time of stroke died during follow-up. Mortality was significantly higher among patients who had a stroke secondary to large-vessel stroke and it was significantly lower in patients with stroke of unknown etiology than in patients with stroke of other causes (relative risk [RR], 1.7; 95% confidence limits [CL], 1.0 to 2.7; and RR, 0.1; CL, 0 to 0.6; respectively). Recurrent strokes occurred in 23 patients (9%) and were fatal in 9. Another 37 patients were treated by a cardiologist during follow-up; 3 had had a myocardial infarct. Fourteen additional patients needed major vascular surgery. Outcomes with the Glasgow Outcome Scale and Barthel Index were generally favorable. Still, only 49% of patients were still alive, were not disabled, had not suffered from recurrent vascular events, or had not undergone major vascular surgery. Only 42% of survivors had returned to work. A majority of survivors reported emotional, social, or physical residuals that lessened the quality of life. CONCLUSIONS: The risks of recurrent vascular events in young adults who have had ischemic stroke are considerable. In addition, a majority of survivors will have residual emotional, social, or physical impairments that hamper employment or lower the quality of life. Further research on the quality of life for young adults who survive stroke is needed.

Adolescent↗
PubMed1993

Oestrogen receptor, progesterone receptor, pS2, ERD5, HSP27 and cathepsin D in invasive ductal breast carcinomas.

Hormonal receptors and markers for prognostic evaluation were detected immunohistochemically in 196 infiltrating ductal breast carcinomas. Immunohistochemical detection of progesterone and oestrogen receptor is a method giving results generally concordant with those of the binding assay. However, immunohistochemical detection seems better. It allows the detection of hormonal receptors on small carcinomas, it is not modified by the endogenous hormones, and it has a slightly better correlation with prognosis and with the response to hormone therapy. Immunohistochemical detection of progesterone receptor has a prognostic value, sorting a negative subgroup with a poor prognosis from the oestrogen receptor positive tumours. These results can be obtained without quantitative immunohistological methods. ERD5, pS2, HSP27 and cathepsin D are associated with oestrogen receptor positivity. pS2 and HSP27 are interesting markers. They characterize a subgroup of oestrogen receptor negative tumours with a good prognosis. Moreover, pS2 is a marker of response to hormone therapy. ERD5 and cathepsin D do not appear to be of value as markers of prognosis.

Adult↗
PubMed1993

Modulation of macrophage Fc gamma receptors by rGM-CSF.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a hematopoietic growth factor being used increasingly to support white blood cell counts in hematologic disorders. Since the survival of IgG-sensitized cells following blood transfusions and the clearance of immune complexes are important in these disorders, we investigated the effect of GM-CSF on the Fc gamma receptors largely responsible for this immune clearance. Human monocytes were cultured in buffer or 100 U/mL of recombinant GM-CSF (rGM-CSF) for 48 hours. Flow cytometry was used to evaluate changes in the expression of the three Fc gamma receptors. Fc gamma RII was the only Fc gamma receptor significantly increased by rGM-CSF. This increase in Fc gamma RII surface protein was correlated with an increase in macrophage binding of erythrocytes sensitized with IgG. In addition, an increase in monocyte binding of IgG-sensitized RBCs was observed in RBCs sensitized with murine IgG2b antibody, which preferentially binds to Fc gamma RII. rGM-CSF also increased the monocyte Fc gamma RII-dependent low-affinity binding site for trimeric IgG. Furthermore, rGM-CSF was observed to increase the expression of monocyte Fc gamma RII mRNA, including that for Fc gamma RIIA. Thus, these studies demonstrate that GM-CSF increases monocyte Fc gamma RII expression and function and suggests that a similar process may be present in vivo. This effect may be either beneficial (increased clearance of immune complexes) and/or detrimental (increased transfusion requirements) in select patients.

Animals↗
PubMed1992

Inhibition by mepacrine and amylase secretion from intact and permeabilized rat pancreatic acini.

In intact rat pancreatic acini, the phospholipase A2 inhibitor mepacrine did not affect basal amylase release but dose-dependently inhibited the carbachol (IC50 65 microM) and CCK-8 (IC50 210 microM)-stimulated amylase release. In permeabilized acini, mepacrine shifted the dose-response curve for calcium to the right by a factor 2 and inhibited the release of amylase stimulated by GTPrS. From these results we conclude that carbachol, CCK-8 and GTPrS probably activate a phospholipase A2 closely coupled to exocytosis.

Amylases↗
PubMed1992

Granulocyte Fc gamma receptor recognition of cell bound and aggregated IgG: effect of gamma-interferon.

Granulocyte Fc gamma receptors are important components in the recognition of IgG-coated cells and immune complexes. Two proteins have been identified on resting human granulocytes which function as Fc gamma receptors, Fc gamma RII (CD32) and Fc gamma RIII (CD16). A third protein, Fc gamma RI (CD64), is not constitutively expressed on resting granulocytes, but can be induced by activation with gamma-interferon. We examined the role of these three Fc gamma receptors on human granulocytes in the binding of both IgG-sensitized erythrocytes and soluble oligomeric IgG. In these studies we employed anti-Fc gamma receptor antibodies which complete for the Fc gamma RII and Fc gamma RIII ligand binding sites. Preincubation of granulocytes with saturating concentrations of high-affinity anti-Fc gamma RII monoclonal antibody did not alter the recognition of IgG sensitized human cells by granulocytes. Furthermore, ligand binding studies demonstrated that anti-Fc gamma RII antibody altered neither the number nor the affinity of granulocyte binding sites for human trimeric IgG. In contrast, Fab anti-Fc gamma RIII inhibited the binding of both IgG (anti-D) sensitized human RBCs and IgG sensitized sheep RBCs. Similarly, a reduction in the expression of Fc gamma RIII by treatment with phosphatidyl-inositol specific phospholipase C reduced PMN recognition of IgG-sensitized cells. Also, anti-Fc gamma RIII decreased the number of granulocyte binding sites for human IgG trimer without a change in receptor affinity. Fc gamma RI, which was induced by gamma-IFN, increased granulocyte recognition of both IgG sensitized RBCs and IgG trimer. These data suggest that Fc gamma RIII is the primary Fc gamma receptor on granulocytes which recognizes IgG sensitized RBCs and low molecular weight complexes of IgG. With gamma-interferon activated granulocytes, Fc gamma RI appears to enhance this recognition process.

Antibodies, Monoclonal↗
PubMed1992

Follicle-stimulating hormone bioactivity in idiopathic normogonadotropic oligoasthenozoospermia: double-blind trial with gonadotropin-releasing hormone.

OBJECTIVE: To identify, among patients with idiopathic normogonadotropic oligoasthenozoospermia, those with low bioactive follicle-stimulating hormone (FSH), possibly because of inadequate gonadotropin-releasing hormone (GnRH) pulsatility, whose bioactive FSH and sperm could be improved by GnRH treatment. DESIGN: Randomized, double-blind, placebo-controlled trial with intranasal (IN) GnRH, followed by open GnRH treatment. SETTING: Outpatient endocrinology clinic. PATIENTS: Twenty-eight infertile men with idiopathic normogonadotropic oligoasthenozoospermia. INTERVENTIONS: Gonadotropin-releasing hormone or placebo was self-administered IN every 2 hours. MAIN OUTCOME MEASURES: Serum immunoreactive and bioactive FSH and semen analyses. RESULTS: Ten men showed a low basal FSH bioactive/immunoreactive ratio, which increased in 5 of them under GnRH without parallel sperm modification. Sperm improvements were observed in 10 patients with no parallel evolution of FSH bioactive/immunoreactive ratio. Unpredicted by sperm changes, three pregnancies developed on placebo and 5 on GnRH. CONCLUSIONS: Low bioactive FSH was not the cause of idiopathic normogonadotropic oligoasthenozoospermia in our patients and could not predict response to GnRH. Pulsatile GnRH did not improve sperm beyond random fluctuations.

Administration, Intranasal↗
PubMed1992

Interleukin-1 alpha as a factor in occlusive vascular disease.

The purpose of this study was to examine the recognized ability of interleukin-1 alpha (IL-1 alpha) to alter the functional properties of endothelial cells and to induce replication of smooth muscle and fibroblasts. Such changes could potentially link IL-1 alpha pathogenetically to the myointimal proliferation of vascular sclerosis. Using a peroxidase-immunoperoxidase immunohistochemical method, saphenous veins and internal mammary arteries were examined for the presence of IL-1 alpha before their implantation as aortocoronary bypass grafts. Occluded saphenous vein grafts requiring replacement because of recurrent angina pectoris also were similarly examined. Interleukin-1 alpha, deposited as a scarlet immunoprecipitate, was seen on the luminal surface, in the subintima, and on the spindle cells and infiltrating macrophages in the media of 13 phlebosclerotic veins before surgical insertion. The remaining 30 unchanged veins did not contain IL-1 alpha. Similarly, IL-1 alpha was not identified in any of the 43 sampled internal mammary arteries that were all considered structurally intact. All the 55 bypass grafts, which were examined by biopsy during revascularization and demonstrated diverse histopathologic abnormalities consisting of reduced luminal patency, myointimal proliferation, mononuclear cell infiltration, mural collagenization, and luminal-mural hemorrhage, also contained widely distributed IL-1 alpha. The observation that IL-1 alpha was absent in all of the internal mammary arteries concomitant with maintenance of normal microanatomic structure may help explain, in part, their recognized resistance to reduction in luminal patency and their improved clinical survival when used as coronary artery bypass grafts. Alternatively, the consistent presence of IL-1 alpha in all vessels with sclerotic histopathologic changes suggests that this cytokine may be an important in situ indicator of and a potential participant in vascular injury. Interleukin-1 alpha may be a pathogenetic factor in the complex processes leading to vascular occlusion.

Adult↗
PubMed1992

Effects of anti-transferrin receptor antibodies on the growth of neoplastic cells.

One approach to creating a state of iron deprivation in tumors is to expose them to monoclonal antibodies against the transferrin receptor (ATRAs). This paper reviews the recent history of studies with ATRAs. Both multivalent (IgM or IgA) and bivalent (IgG) ATRAs exhibit anti-tumor activity in vitro and in vivo, but IgG ATRAs appear to be most effective when used with an iron chelator such as deferoxamine or when used in pairs. Much more information is needed in order to understand: (1) how ATRAs work by themselves and in conjunction with chelators; (2) why ATRAs differ from one another in terms of their inhibitory potency; (3) whether ATRAs can be used successfully in conjunction with other anti-tumor agents, and (4) why tumors exhibit marked differences in their sensitivity to the effects of ATRAs. The toxicity of iron deprivation arising from ATRA treatment alone seems modest, but only further experimental work in vivo and in phase-1 clinical trials can determine whether the most recent observations can be converted into truly useful therapeutic tools.

Animals↗
PubMed1992

Comparative study of in situ hybridization and immunohistochemical techniques for the detection of human papillomavirus in lesions of the uterine cervix.

Among the techniques currently used for the detection of human papillomavirus (HPV) in genital lesions, only two correlate HPV with the histopathological findings of the lesion: immunohistochemistry and in situ hybridization. Consequently, we were prompted to carry out a comparative study on both techniques to check their utility and efficacy as routine diagnostic methods. 52 biopsy specimens of uterine cervix diagnosed histopathologically as condylomas and cervical intraepithelial neoplasia+koilocytosis were studied by immunohistochemical and in situ hybridization techniques using a polyclonal antibody against the common antigen of the HPV capsid and three biotinylated DNA probes specific to HPV types 6/11, 16/18 and 31/35/51. Immunohistochemistry detected 21 positive cases (40.38%), whereas in situ hybridization detected 40 positive cases (76.92%); of the latter, 30 were positive for HPV types 6/11, 3 for HPV types 16/18 and 11 for HPV types 31/35/51. The results suggest that in situ hybridization is a more sensitive technique than immunohistochemistry. However, we recommend the use of both techniques in the case of potentially malignant lesions since better prognostic information can be obtained from joint analysis of both results.

Adolescent↗