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Biomedical subjects

F García

Publications and source records attributed to F García.

At least 199 records · Page 11Linked to original sources
PubMedDate not supplied

A seroepidemiological study of human immunodeficiency virus infection in northeast Zaire.

To evaluate the incidence of human immunodeficiency virus type 2 infections in an endemic African area, we have studied 134 patients from Northeast Zaire. Sera were tested for HIV-1 and HIV-2 antibodies to asses cross-reactivity or a possible double infection. Sixty five (48.5%) serum samples were reactive for HIV-1 and six (4.5%) for HIV-2 using specific Western blots. The enzyme immunoassays used to detect HIV-2 showed cross-reactivity with HIV-1 in 17 samples (16.5%). Tests based upon synthetic peptides corresponding to specific from human immunodeficiency viruses confirm their ability to discriminate antibodies directed against both viruses in 42/47 samples (89.4%); in 5/47 (10.6%) this test could not distinguish double infection from cross-reactivity. We suggest that the high number of sexual partners may be responsible for HIV transmission in our study group.

AIDS Serodiagnosis↗
PubMedDate not supplied

[Somatostatin receptor scintigraphy. When would a SPECT study be performed?].

UNLABELLED: Somatostatin receptor scintigraphy has become an essential tool in the treatment planning of patients with carcinoid tumor (CaT) and pancreatic neuroendocrine tumors (PNET). However, the contribution of SPECT images in the diagnosis and staging of these tumors has not been well established. OBJECTIVE: 1) To find out if SPECT improves the sensitivity of planar imaging and adds any value to tumor diagnosis, and 2) To determine under which circumstances SPECT images must be obtained. MATERIAL AND METHODS: We have evaluated 49 patients, 26 females and 23 males, using both planar and SPECT 111In-DTPAOC images. The patients were classified into three groups according to their clinical indication: Group A: Indolent symptoms of CaT or PNET (n = 9); Group B: Known or functioning CaT or PNET tumors (n = 22); Group C: Post-surgical follow-up (n = 18). The total number of SPECT studies were 51 (37 abdomen, 13 thorax and 1 brain). In all cases SPECT was performed 24 hours after 111In-DTPAOC injection. Scintigraphic images were compared with surgical findings in 17 patients and with a synthesis of biochemical, clinical and CT findings in the other patients. RESULTS: 16 primary lesions were detected with planar images whereas SPECT detected 18. The two tumors detected only by SPECT were a bronchial CaT and an insulinoma located in the pancreatic tail. Planar and SPECT image sensitivities were 66.6% and 75% respectively. Twenty one patients developed metastatic disease. Sensitivities of planar and SPECT images for metastases were 76.1% and 90.4% respectively. Furthermore, SPECT helps planar images in the evaluation of six patients with uncertain images (lesions with low receptor density or with an uncertain scintigraphic localization). Therefore, in 15.6% of patients with primary or metastatic tumors, planar images were normal whereas SPECT was abnormal and SPECT provided an added value in 21.8% of the studies with abnormal planar images. CONCLUSIONS: We recommend the use of SPECT images in: 1) Patients with specific functional clinical syndrome or with a known CaT or PNET and normal planar images. 2) When planar images are abnormal only in primary tumor. 3) In order to confirm the absence of other metastases in patients with known liver metastases. 4) In order to enhance the detection of lesions with low receptor density and uncertain planar images and 5) In order to determine exactly the anatomic location of some lesions

Adult↗
PubMedDate not supplied

[Diabetes mellitus and pancreatic tumor].

A 68 year old Ecuadorian man was investigated for polyuria, polydipsia and weight loss of 3 kg during the previous two months. Insulin dependent diabetes mellitus was diagnosed 10 year before admission and treated with appropriate diet and insulin (35 U/d). 18 months before was diagnosed in El Ecuador of "multiple liver nodes non-suggestive of malignancy". Physical examination showed a large multinodular petrous hepatomegaly. There was no evidence of skin lesions. Results of laboratory studies included a basal plasma glucose level that ranged between 275-367 mg/dl (N=60-100), glycosylated haemoglobin of 8.9% (N<5) and a serum albumin of 2.8 gr./dl (N=3.4-4.8). At admission non-other laboratory alterations were detected. Computed tomography showed a mass on the head of the pancreas with loco-regional lymph nodes and liver metastases. Tumor markers were normal. Fine-needle aspiration cytology of the liver masses revealed the presence of liver metastases of a non-differentiated malignant tumor. A 111In-DTPAOC scintigraphy revealed the presence of somatostatin receptors in the liver metastases, also detecting the presence of multiple bone metastases in the axial and appendicular skeleton. Plasma glucagon level was 678 pg/ml (N<250). A diagnosis of metastatic glucagonoma was established and therapy with streptozocin, 5-FU, insulin and synthetic somatostatin analogs was initiated. Three months after the therapy initiation the patient was symptom free. Some weeks after the patient suffered from left hip pain, and a control 111In-DTPA scintigraphy showed progression of his bone metastases. In conclusion, glucagonoma must be suspected in all diabetic patients with metastatic liver, even in absence of necrotic migratory erythema. In these circumstances, plasmatic glucagon level and somatostatin receptors scintigraphy will be a useful tool for establishing the final diagnosis.

Aged↗
PubMedDate not supplied

[Carcinoid tumor and bone metastases: diagnosis by somatostatin receptor scintigraphy].

OBJECTIVE: The aim of this study has been to retrospectively assess the usefulness of 111In-DTPAOC scintigraphy in the detection of bone metastases (BM) in patients diagnosed of carcinoid tumour (CaT). MATERIALS AND METHODS: Between June 1995 and April 2003 78 111In-DTPAOC studies were consecutively performed in 58 patients, 31 females and 27 males, 28 to 73 years old, with a histological diagnosis of CaT. Moreover, whole body bone scans (BS) using 99mTc-MDP were performed in 13 of these patients. The patients were classified into three groups: Group A: Initial CaT staging (n = 23); Group B: CaT staging after surgery (n = 14); and Group C: Post-treatment CaT re-staging (n = 29). In this last group, 6 patients of group A and 2 patients of group B were included. In only 2 patients the diagnoses of bone metastases were established before the 111In-DTPAOC scan. RESULTS: Twenty six (44.8 %9 of the 58 patients with CaT had metastatic disease: 15 patients with hepatic metastases, associated with BM in 4 of them, 10 patients with hepatic and extra-hepatic metastases, abdominal and/or thoracic, associated with BM in 4 and in one patient, the BMs were the only metastases detected. The global incidence of BM in patients diagnosed with CaT was 15.5 % (9/58), whereas the incidence of BM in patients with metastasic disease was 34.6 % (9/26). Significant differences (p = 0.0035) were found on the incidence of BM in patients with or without hepatic metastases. In 4 patients, BMs were detected during the initial staging (group A), whereas in 5 patients, BMs were detected during the post-treatment re-staging (group C). During diagnosis, 4 of the 9 patients with BM had bone pain. BM were multiples in 8 patients, affecting axial skeleton in 4 and axial and appendicular skeleton in 4. One patient had a diffuse infiltration of bone marrow. BS was positive in 8 of the 9 patients with BM. In these 8 patients with abnormal BS, 111In-DTPAOC scintigraphy provides similar information to the BS in one patient, shows a greater number of bone lesions in 3, whereas BS was superior in 5 patients. Four of the patients with BM died between 6 and 47 months after diagnosis (mean: 29.7 months). CONCLUSIONS: BMs are preferably located on axial skeleton, can be asymptomatic and are associated with hepatic metastases. Although the 111In-DTPAOC scintigraphy is able to detect some BM earlier than BS, the information provided by both studies is complementary. In patients with CaT, any invasive therapy on the hepatic metastases make it necessary to exclude extrahepatic metastases, including bone ones, and the somatostatin receptor scintigraphy is the diagnostic method of choice.

Adult↗
PubMedDate not supplied

[Renal damage in vesicoureteral reflux associated to duplex pyeloureteral system].

UNLABELLED: Duplex pyeloureteral system (DPS) is common and it can be associated to others anomalies, as vesicoureteral reflux (VUR) in the lower moiety and ureterocele in the upper moiety. The VUR in a DPS can be primary or secondary. Assessment of parenchymal uptake is important. OBJECTIVE: To determine the presence of renal damage (RD) in children with a complete refluxing DS in relationship with clinical presentation and type of VUR. PATIENTS AND METHODS: Retrospectively we evaluated 56 children; 39 girls and 17 boys with an average age of 3.58 years old, with VUR into complete DPS (61 renal units [RU] with DS, 45 of them with primary VUR). Forty-four out of 56 children were evaluated due to urinary tract infection. RESULTS: Twenty-eight out of 61 RU (46 %) had RD. Twenty-one out of 45 RU with primary VUR (46.7 %) had RD and 7 out of 16 RU with secondary VUR had RD (ns). 72.7 % of children with antenatal diagnosis had RD versus 40.8 % of those studied after urinary tract infection (p = 0.04). CONCLUSION: RD is frequent in VUR into complete DPS; 46 % in our experience. There is no significant difference between primary and secondary VUR. RD was more frequent in the group of children with antenatal diagnosis. Renal scintigraphy provides an accurate assessment of the functional renal parenchyma, supporting the therapeutical decision.

Child↗
PubMedDate not supplied

Development of a new cyclosporine formulation based on poly(caprolactone) microspheres.

The present study describes the development of a new cyclosporine formulation based on polycaprolactone (PCL) microspheres (MS) prepared by the solvent evaporation method. Ternary phase diagrams were used to identify the domains where MS were formed. The application of central composite designs established the influence of several technological (stirring speed) and formulation factors (polymer and surfactant amounts, and organic solvent volume) on the size of PCL MS. Cyclosporine-loaded MS of a size around 2.5 microm were prepared and characterized. The stability of the systems, either alone or loaded with cyclosporine, stored at 8 degrees C and room temperature (RT) was assessed as well. Freeze-drying was evaluated as an alternative method to achieve long-term stability. The experimental design showed that the stirring speed and the organic phase volume were the only parameters significantly affecting the MS size. Experimental conditions selected to obtain CyA-loaded MS of 2.5 microm resulted in a high entrapment percentage (98.4 +/- 0.66%) with the drug dissolved or molecularly dispersed within the dense polymeric matrix of MS. After 12 months of storage at 8 degrees C and RT, PCL MS remained physically stable, although the crystallinity of the polymer increased by 35% upon storage at both temperatures. Freeze-drying studies revealed that MS could be successfully lyophilized in the absence of cryoprotectants without significant changes of the drug entrapment; however, the presence of at least 5% cryoprotectant was essential to keep the initial particle size. Therefore, a stable MS-based CyA formulation was easily prepared and characterized. This formulation offer the possibility of CyA administration through different routes.

Calorimetry, Differential Scanning↗
PubMedDate not supplied

Human male infertility: chromosome anomalies, meiotic disorders, abnormal spermatozoa and recurrent abortion.

Human male infertility is often related to chromosome abnormalities. In chromosomally normal infertile males, the rates of chromosome 21 and sex chromosome disomy in spermatozoa are increased. Higher incidences of trisomy 21 (seldom of paternal origin) and sex chromosome aneuploidy are also found. XXY and XYY patients produce increased numbers of XY, XX and YY spermatozoa, indicating an increased risk of production of XXY, XYY and XXX individuals. Since XXYs can reproduce using intracytoplasmic sperm injection (ICSI), this could explain the slight increase of sex chromosome anomalies in ICSI series. Carriers of structural reorganizations produce unbalanced spermatozoa, and risk having children with duplications and/or deficiencies. In some cases, this risk is considerably lower or higher than average. These patients also show increased diploidy, and a higher risk of producing diandric triploids. Meiotic disorders are frequent in infertile males, and increase with severe oligoasthenozoospemia (OA) and/or high follicle stimulating hormone (FSH) concentrations. These patients produce spermatozoa with autosomal and sex chromosome disomies, and diploid spermatozoa. Their contribution to recurrent abortion depends on the production of trisomies, monosomies and of triploids. The most frequent sperm chromosome anomaly in infertile males is diploidy, originated by either meiotic mutations or by a compromised testicular environment.

Abortion, Habitual↗
PubMedDate not supplied

[Treatment of bone metastatic pain with Sm153-EDTMP. Evaluation of the analgesic response and the existence of differences according to the primary tumor and the metastatic pattern].

AIMS: To evaluate the response to Sm153-EDTMP treatment in patients with metastatic bone pain and the existence of differences in the response according to the scintigraphic pattern (99mTc-MDP) and the primary tumor. MATERIAL AND METHODS: We have evaluated the response to Sm153-EDTMP treatment in 32 patients (17 male and 15 female) who received 38 doses (1 mCi/kg). The primary tumor was prostate cancer in 15 patients, breast in 13, lung in 2, intestinal carcinoid in one and unknown in one. Two types of response were considered: a) effective and b) non-effective. Patients were classified into 3 groups according to the metastatic pattern: 1) Superscan (SS), 2) Generalized metastases (GM) and 3) Regional metastases (RM). RESULTS: There was effective response in 24 doses (63.15%) and non-effective in 14 (36.84%). The mean duration of the response was 12.08 weeks. Patients with GM pattern showed 16 effective responses (76.19%) and 5 non-effective (23.8%). In SS pattern there were 6 effective responses (60%) and 4 non-effective (40%) and 2 effective (28.57%) and 5 non-effective (71.53%) in RM pattern. These differences did not reach statistical significance (p > 0.05). We did not find differences in the response between prostate cancer (12 effective and 6 non-effective) and breast cancer (10 effective and 6 non-effective) (p = 0.79968). CONCLUSIONS: Sm153-EDTMP treatment is efficacious in patients with metastatic bone pain with effective response in 63.15% of the treatments. The response percentage was lower in patients with RM pattern but the differences did not reach statistical significance. There were no differences in the response between prostate and breast cancer patients.

Adult↗
PubMedDate not supplied

Effects of L-741,741, a selective dopamine receptor antagonist, on anxiety tested in the elevated plus-maze in mice.

Dopamine systems are involved in modulation of anxiety. Although the action of D1/5, D2 and D3 receptor antagonists on anxiety has been documented in different animal models, little is known about the influence of D4 dopamine antagonists. The aim of this study was to examine the effects of L-741,741 (0.75, 1.5 and 3 mg/kg i.p.), a selective D4 dopamine receptor antagonist, on anxiety tested in the elevated plus-maze. Forty-eight albino adult male mice of the OF.1 strain were used. Animals were randomly allocated to one control group receiving physiological saline and dymethyl-sulphoxide (DMSO) (10%) and three experimental groups receiving L-741,741 injections. Tests were performed 30 min after injections for a duration of 5 min. A number of classical parameters were collected: i) open arm duration; ii) closed arm duration; iii) central platform duration; iv) open arm frequency; v) closed arm frequency; vi) central platform frequency; and vii) number of rearings. L-741,741 did not produce any significant behavioral changes under present test conditions, suggesting that the dopamine D4 receptor might not be involved in the modulation of anxiety-related behaviors in the plus-maze.

Animals↗