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Biomedical subjects

F Gomez

Publications and source records attributed to F Gomez.

At least 19 recordsLinked to original sources
PubMed1998

[Social representations of male sterilization. Vasectomy as viewed by professional counselors at the Men's Clinic in Bogotá,Colombia]

Vasectomy service providers at the Clínica del Hombre (Men's Clinic) in Bogotá, Colombia, construct their representations concerning male sterilization on the basis of biomedical discourse, their interaction with clinic users, and their own life experiences. During provision of such services, the counselors are the health professionals who have the closest contact with these clients of the clinic. Counselors are in charge of exploring their motivations in requesting the service, in addition to providing information allowing them to take a calm, sound decision. They also directly filter demand based on their experience, knowledge, and skills, in permanent negotiation between institutional criteria (number of children and gap between them, client's age, steadiness of couple's relationship, and conviction concerning the decision), and their perception and assessment of the client. An analysis of the counselors' representations of decision-making as pertaining to vasectomy indicates that it is a relatively simple and harmless procedure as well as a liberating option in terms of family planning.

Journal Article↗
PubMed1998

Time to relapse has prognostic value in patients with aggressive lymphoma enrolled onto the Parma trial.

PURPOSE: The purpose of this study was to investigate the prognostic value of time to relapse in 188 adult patients with intermediate- or high-grade non-Hodgkin's lymphoma (NHL) included on the Parma trial at the time of their first relapse. PATIENTS AND METHODS: The median follow-up of these patients is 102 months after registration onto the Parma study. Time to relapse was calculated from initial diagnosis, and a cutoff of 12 months was used to separate 77 patients defined as early relapse from 111 patients defined as late relapse. RESULTS: Patients with early and late relapses had significantly different overall response rates to salvage therapy with two courses of dexamethasone, high-dose cytarabine, and cisplatin (DHAP; 40% v 69%; P=.00007) and different 8-year survival rates (13% v 29%; P=.00001). Features at relapse with a negative prognostic value in univariate analysis were higher than normal lactic dehydrogenase (LDH) levels, tumor size greater than 5 cm, Ann Arbor stages III to IV, and Karnofsky score less than 80%. Therefore, multivariate analyses were performed. Time to relapse (P=.001) and LDH levels at relapse (P=.003) had independent prognostic value, whereas tumor size did not reach statistical significance in the logistic model that predicted overall response after two courses of DHAP. The study of prognostic factors for overall survival (OS) and progression-free survival (PFS) confirmed the prognostic value of time to relapse (P < .0001 for OS and P=.005 for PFS) independent of response or treatment after two courses of DHAP. CONCLUSION: Time to relapse may be used to stratify patients at time of first relapse of intermediate to high-grade non-Hodgkin's lymphoma.

Adult↗
PubMed1998

Subcutaneous interleukin-2, interferon alfa-2a, and continuous infusion of fluorouracil in metastatic renal cell carcinoma: a multicenter phase II trial. Groupe Français d'Immunothérapie.

PURPOSE: A phase II trial was designed to determine the efficacy and the tolerance of interleukin-2 (IL-2), interferon alfa-2a (IFNalpha), and fluorouracil (5-FU) in patients with metastatic renal cell carcinoma. PATIENTS AND METHODS: One hundred eleven patients were included. Patients received subcutaneous IL-2 9 x 10(6) IU daily for 6 days and IFNalpha 6 x 10(6) IU on days 1, 3, and 5 every other week for 8 weeks. 5-FU was administered through a continuous infusion at 600 mg/m2 for 5 consecutive days for 1 week every 4 weeks. RESULTS: The response rate was 1.8% (95% confidence interval [CI], 0% to 4.3%) with only two partial responses (PRs). Toxicity was moderate with 3.6% grade 4 events and two deaths related to treatment. CONCLUSION: This regimen of IL-2, IFNalpha, and 5-FU in patients with metastatic renal cell carcinoma was ineffective. The results raise the question of the dose and schedule of subcutaneous cytokines that must be used in metastatic renal carcinoma.

Adult↗
PubMed1998

Traumatic pseudoaneurysm of the axillary artery following anterior dislocation of the shoulder. Case report.

Vascular complications are rare in cases of simple anterior dislocation of the shoulder but the axillary artery or its branches may be damaged. Very few cases are found in the literature reporting false aneurysms of axillary artery secondary to blunt trauma to the shoulder. A case of pseudoaneurysm of the axillary artery in a 75-year-old woman is reported. Diagnosis was suspected because large pectoral haematoma with haemodynamic instability appeared a few hours later after manual reduction of the dislocation. The pseudoaneurysm was confirmed with selective angiography of the axillary artery. Arteriography should be performed whenever vascular injury is suspected. Delayed recognition of these lesions may lead to permanent neurologic deficits despite adequate vascular repair of the axillary artery. A coordinated vascular and orthopaedic approach and prompt surgical treatment may assure full upper limb function. Although endovascular treatment of these lesions could seem attractive, we prefer to use open surgical techniques because they allow us to treat frequent concomitant injuries and perform decompression of the axillar fossa because of the large haematoma.

Accidental Falls↗
PubMed1997

Arginine vasopressin (AVP) depletion in neurons of the suprachiasmatic nuclei affects the AVP content of the paraventricular neurons and stimulates adrenocorticotrophic hormone release.

Arginine vasopressin (AVP) produced in the hypothalamic suprachiasmatic nuclei (SCN) plays a role in establishing neuroendocrine rhythms and, in particular, in regulating the corticotrope axis rhythm. It has recently been shown that AVP from SCN inhibits corticosteroid release. In order to investigate the influence of suprachiasmatic AVP on the different peptidergic systems through the hypothalamus, SCN neurons containing AVP were functionally lesioned by using toxins associated with a cytotoxic monoclonal antibody (MAb) raised against AVP. Six days later, the AVP contents and AVP mRNA were measured in different hypothalamic and extrahypothalamic sites. Adrenocorticotrophic hormone (ACTH) concentration was also measured in plasma. Microinjection of the AVP-MAb/toxin mixture into SCN brought about a significant decrease in the AVP expression in SCN. This is demonstrated by the decrease in the AVP immunoreactive content (24%, P < 0.01) and the decrease of AVP hybridized mRNA (33%, P < 0.01). This points to the efficiency of the microinjection in decreasing the production of AVP in the injection area. Modifications of the AVP contents in the two subdivisions of the hypothalamic paraventricular nucleus (PVN) were also observed. AVP contents decreased in the parvocellular subdivision (pPVN); this is coherent with the AVP depletion in SCN since pPVN is the major site of the SCN hypothalamic efferences. AVP content and AVP mRNA increased in the magnocellular subdivision (mPVN); this also confirms the difference in AVP synthesis regulation according to the PVN subdivisions. The microinjection did not modify AVP expression in supraoptic nuclei or oxytocin (OT) immunoreactive content in the main hypothalamic OT containing sites. Plasma ACTH values were double (P < 0.02) the values measured under non-specific IgG treatment 10 hr after lights on. This probably resulted from the stimulation of the hypothalamo-pituitary-adrenal system since corticotrophin-releasing hormone (CRH) mRNA increased simultaneously by 24% (P < 0.05) in the PVN and the immunoreactive CRH content of the median eminence significantly decreased (26%, P < 0.05). Overall, our data confirm that AVP produced in the SCN inhibits the CRH-adrenocorticotrope axis in normal conditions, probably because of SCN projections of AVP neurons on the PVN.

Adrenocorticotropic Hormone↗
PubMed1997

In vivo and in vitro effects of somatostatin and insulin on glucagon release in a human glucagonoma.

Inhibition of pancreatic glucagon secretion has been reported to be mediated by glucose, insulin and somatostatin. As no human pancreatic alpha-cell lines are available to study in vitro the relative importance of insulin and glucose in the control of pancreatic glucagon release, we investigated a patient presenting with a malignant glucagonoma who underwent surgical resection of the tumour. Functional somatostatin receptors were present as octreotide administration decreased basal glucagon and insulin secretion by 52 and 74%, respectively. The removed tumour was immunohistochemically positive for glucagon, chromogranin A and pancreatic polypeptide but negative for insulin, gastrin and somatostatin. The glucagonoma cells were also isolated and cultured in vitro. Incubation experiments revealed that change from high (10 mM) to low (1 mM) glucose concentration was unable to stimulate glucagon secretion. A dose-dependent inhibition of glucagon release by insulin was however, observed at low glucose concentration. These findings demonstrate that insulin could inhibit glucagon secretion in vitro in the absence of elevated glucose concentrations. These data suggest, as observed in vivo and in vitro in several animal studies, that glucopenia-induced glucagon secretion in humans is not mediated by a direct effect of low glucose on alpha-cells but possibly by a reduction of insulin-mediated alpha-cell suppression and/or an indirect neuronal stimulation of glucagon release.

Chromogranin A↗
PubMed1997

Insulinoma associated with a case of multiple endocrine neoplasia type I: Functional somatostatin receptors and abnormal glucose-induced insulin secretion.

A sporadic case of multiple endocrine neoplasia type I with coexisting insulinoma and hyperparathyroidism was investigated in vivo and in vitro. The insulinoma was localized by somatostatin receptor scintigraphy and these receptors were functionally active. Octreotide administration decreased the basal insulin and glucagon secretion by 90 and 46%, respectively. Immunocytochemistry of the insulinoma tissue was positive for insulin, chromogranin A and neuropeptide Y. The insulinoma cells were also isolated and cultured in vitro. Incubation experiments revealed that a low glucose concentration (1 mmol/l) was sufficient to increase cytosolic free calcium and to produce a maximal glucose-induced insulin release. Northern blot analysis of RNA obtained from the tumor showed a high abundance of the low Km glucose transporter GLUT1 but no transcript for the high Km glucose transporter GLUT2. The abnormal distribution of glucose transporters probably relates to the abnormal glucose sensing of insulinoma cells, and explains their sustained insulin secretion at low glucose concentrations. Whether these abnormalities share a pathogenetic link with the presence of functionally active somatostatin receptors remains to be elucidated.

Actins↗
PubMed1996

Fawn-hooded rats show enhanced active behaviour in the forced swimming test, with no evidence for pituitary-adrenal axis hyperactivity.

Fawn-hooded (FH) rats have been reported to have high basal corticosterone levels that can be normalized by antidepressant administration. In the present work, some behavioural and endocrine aspects were compared in FH and Sprague-Dawley (SD) rats. No interstrain differences in basal corticosterone levels or response to acute tail-cut stress were observed either in the morning or in the evening. Relative adrenal weight was lower in FH than SD, and relative thymus weight was, accordingly, higher in FH than SD rats. FH rats were hyperactive in the holeboard and showed behaviour similar to that of SD in the plus-maze. In contrast, FH rats showed greater levels of active behaviour (struggling) and lower levels of immobility than SD rats in the forced swimming test (FST). After desipramine (DMI) administration the differences between the two strains in the FST were more marked than in vehicle-treated animals. These results indicate that FH rats show no signs of pituitary-adrenal (PA) hyperactivity or depression-like behaviour, and therefore they are not an appropriate animal model of depression.

Adrenal Glands↗
PubMed1996

Normogonadotropic primary amenorrhea in a growth hormone-deficient woman with ectopic posterior pituitary: gonadotropin pulsatility and follicle-stimulating hormone bioactivity.

We studied the gonadotropic function in a 25-year-old woman suffering from congenital GH deficiency, complaining of primary amenorrhea and wishing to become pregnant. She disclosed a hypoplasic anterior pituitary within a small sella turcica and an ectopic posterior pituitary lobe located below the median eminence. Immunoreactive LH and FSH plasma levels were normal, basal and in response to a GnRH iv bolus but estradiol was low. LH pulse frequency was elevated and FSH bioactivity was low in a granulosa cell aromatase bioassay. Pulsatile administration of iv GnRH at a slower, normal pace, failed to induce ovulation or to increase FSH bioactivity, with or without concomitant GH replacement. However treatment with exogenous im gonadotropins, when preceeded by GH replacement, succeeded in inducing mature oocytes and pregnancy. We concluded that the hypogonadism observed in this patient was due to rapid GnRH pulsatility and poor biological activity of endogenous FSH.

Adult↗
PubMed1996

Neuropeptide Y secretion from a human insulinoma.

Neuropeptide Y (NPY) is a 36 aminoacid peptide known to inhibit glucose-stimulated insulin secretion. NPY has been shown to be synthesized and secreted by rat islets of Langerhans. More recently, we described the presence on NPY within human islets of Langerhans and in several pancreatic endocrine tumors. In this report, we describe the case of a patient presenting with an insulinoma who underwent the surgical resection of the tumor and was studied in vivo and in vitro for NPY production. Using a highly specific and sensitive two-site amplified enzyme-linked immunosorbent assay, we detected high plasma NPY levels in the patient prior to the surgical resection of the tumor which returned to normal after surgery. NPY was secreted from the tumor when kept in primary cell culture. Furthermore, immunohistochemistry of the insulinoma revealed the presence of NPY and its C-flanking peptide together with insulin, chromogranin and neuron specific enolase. It is concluded that elevated circulating NPY levels observed in this patient with an insulinoma reflected in vivo secretion by the tumor and it is hypothesized that NPY could potentially be used as an endocrine marker in patients with suspected insulinoma.

Aged↗
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↗