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Biomedical subjects

A Diaz

Publications and source records attributed to A Diaz.

At least 37 records · Page 2Linked to original sources
PubMed2001

Comparison of peripheral arterial reconstruction in diabetic and non-diabetic patients: a prospective clinic-based study.

UNLABELLED: To assess the efficacy and safety of lower extremity arterial reconstruction in diabetic and non-diabetic subjects during a 3-year period. A prospective clinic-based study between 1994-1999 in Area 7, Madrid, with a population of 569307 and an estimated diabetic population of 37932 (15505 men and 22427 women). The level of arterial reconstruction and associated risk factors were ascertained. RESULTS: A total of 588 peripheral revascularization surgical procedures were performed in 481 patients. The diabetic patients (n=174, 36.2%) underwent 222 surgical procedures (including 48 follow-on operations, 21.6%), and 307 non-diabetic subjects underwent 366 surgical procedures (59 follow-on operations, 16.1%). The numbers of surgical procedures per 100000 people at risk and year were 18.8 and 1.8 for non-diabetic men and women, respectively, and 145.1 and 29.0 for men and women with diabetes mellitus (7.7- and 16.2-fold, respectively). Age at reconstruction surgery was 2 and 5 years earlier in non-diabetic than in diabetic men and women, respectively. Diabetic patients had a higher neuropathy score (P<0.05) and were less frequently smokers (P<0.05) than non-diabetic subjects. Diabetic subjects more frequently had distal reconstruction while proximal arterial reconstruction was more often performed in non-diabetic subjects. Between 64.6 and 80.4% of people with diabetes and 82.3 and 88.9% of non-diabetic subjects had no complications during their in-hospital stay. Distal amputation simultaneous to arterial reconstruction was the most frequent morbidity of people with diabetes during the study (P<0.05). Despite a graft occlusion rate after femoropopliteal revascularization significantly higher than in non-diabetic people (P<0.05), diabetic people more often required lower extremity amputations (LEAs) for the same level of bypass (P<0.01). Cumulative limb salvage rates were lower in diabetic patients than in non-diabetic subjects at femoropopliteal (49.2 vs. 89.7%; P<0.001), femorodistal (73.5 vs. 95.2%; P<0.01), and distal reverse (77.9 vs. 87.3%; P<0.05) arterial reconstruction, at the end of the third year, but similar after aorto-iliac reconstruction (93.1 vs. 97.5%). A higher neuropathy score and the presence of foot ulcers were associated to significantly lower limb salvage in diabetic patients (P<0.05), but not in non-diabetic people. Survival rates after 3 years were similar between diabetic and non-diabetic populations after aorto-iliac (93.1 vs. 97.5%), femoropopliteal (97.2 vs. 90.3%), and distal reverse (93.2 vs. 98.1%) revascularization, and slightly lower in diabetic compared to non-diabetic patients after femorodistal revascularization (82.1 vs. 96.3%; P<0.05). CONCLUSION: Although limb salvage after arterial reconstruction is lower in diabetic than in non-diabetic subjects, particularly in those with a higher neuropathy score, this surgical approach can be applied in both diabetic and non-diabetic subjects with otherwise similar outcome.

Aged↗
PubMed2001

Brain copper, iron, magnesium, zinc, calcium, sulfur and phosphorus storage in Wilson's disease.

PROJECT: Wilson's disease (WD) is an inherited disorder of copper metabolism characterised by juvenile liver cirrhosis and by neurological symptoms. Copper levels in brain in WD have been reported to be 10 to 15 fold normal values, depending on the different brain regions. Being very few data on copper distribution in central nervous system in WD available, it seemed of interest to study the concentration of copper and of other trace elements (Zn, P, Mg, Ca, Fe and S) in the brain of a patient died for WD. PROCEDURE: a 56 year old woman affected by WD was admitted to our hospital with signs of hepatic failure and died few days later. At autopsy, a brain slice extending from the left to the right hemisphere was divided in 28 samples. On each sample Copper, Iron, Magnesium, Phosphorus, Sulphur, Zinc and Calcium were determined by Induced Coupled Plasma Atomic Emission Spectroscopy. RESULTS: the mean concentration of copper, ranging from 88 to 158 microg/g of dry tissue in all the brain specimens was higher than literature reference values, while that of the other tested elements was considerably lower. CONCLUSIONS: 1) In the brain of WD patient examined the status of trace elements was extensively altered. Further studies are necessary to correlate the concentration of trace elements with pathological lesions and with clinical pictures. 2) The elements considered in our study showed an uneven distribution in different brain areas.

Brain↗
PubMed2001

Determination of the odor threshold concentrations of iodinated trihalomethanes in drinking water.

Iodinated trihalomethanes (ITHMs) have been usually considered the disinfection byproducts suspected of causing medicinal odor episodes in treated water around the world. The odor threshold concentration (OTC) of mixed ITHMs (bromochloroiodo-, bromodiiodo-, chlorodiiodo-, dibromoiodo-, and dichloroiodomethane) which were previously synthesized -- because commercial standards are not available-- were determined by using two sensory techniques: flavor profile analysis (FPA), performed by an experienced panel trained in identifying odors and tastes in water; and gas chromatography coupled with olfactometry (GCO). FPA results gave a theoretical OTCs range from 0.1 to 8.9 microg/L and ITHMs were described as sweet, solvent, and medicinal products. The lowest experimental value (OTC(exp)) obtained from the six ITHMs, 0.03 microg/L, corresponded to iodoform.

Chromatography, Gas↗
PubMed2001

Assessment of in vivo complement activation on the Echinococcus granulosus hydatid cyst wall.

The larval stage of the parasite Echinococcus granulosus causes hydatid disease. The hydatid cyst is potentially capable of activating host complement, since it is a large, persistent, carbohydrate-rich structure, coated with host immunoglobulins, and localized in the host's internal organs. Nonetheless, in vitro studies have suggested that the cyst surface, the hydatid cyst wall (HCW), is a poor complement activator. In this study, we assessed the occurrence of in vivo complement activation on the hydatid cyst by measuring the levels of two complement activation products, C3d and complexes bearing a C9 activation neoepitope (TCC/MAC), in extracts from HCW of human origin. Low amounts of C3d and TCC/MAC were found in HCW in comparison with their levels in normal human plasma and activated human sera, suggesting that in vivo complement activation on HCW is efficiently down-regulated. This regulation may contribute to limit host inflammation which has been observed to correlate with parasite degeneration and death.

Animals↗
PubMed2001

Inadequate drug advice in the pharmacies of Guatemala and Mexico: the scale of the problem and explanatory factors.

A study of urban pharmacies in Guatemala and in Chiapas, southern Mexico, was undertaken to analyse the scale of the inadequate drug advice provided, and to identify the contributing factors. The estimate of the scale of the problem was based on the results of 969 approaches to 191 pharmacies by 'magic clients' (i.e. researchers pretending to be looking for treatment for relatives who had one of three 'tracer' diseases), interviews with 4469 pharmacy users as they left the same 191 pharmacies, and a comparison of the quality of advice offered by public and private pharmacies in Guatemala (based on exit interviews with 150 users). The contributing factors were explored using a provider survey (interviews with 166 pharmacy supervisors and 371 drug vendors), an in-depth study analysing large-chain and independent Mexican pharmacies, and a review of the national drug policies in both countries. Although only about 11% of all drug treatments were recommended in pharmacies (the rest being prescribed by physicians or recommended by kin-groups), this still represents large numbers of treatments. Overall, 501 individuals who visited the 191 study pharmacies over 2 days of observation received drugs recommended by pharmacy staff. Much of the pharmacy advice was revealed to be poor: > 80% of the treatments recommended to the 'magic clients' for diarrhoeal disease or acute respiratory infection included unnecessary or dangerous drugs. Few of those who worked in the pharmacies based their advice on careful case histories. Drug advice in pharmacies was much more likely to be of poor quality than that from physicians or even kin-groups. The factors behind this poor advice were identified as a lack of knowledge about standard treatments and legal regulations, incompetence among pharmacy staff, commercial pressures (particularly in the large-chain pharmacies of Mexico), and a failure to implement the existing regulations covering the drug market and its retail practices. It is recommended that: (1) pharmacy owners and drug vendors be made more aware that the selling of drugs should involve provision of healthcare (as well as reasonable profit-making); (2) existing drug-related legislation be reinforced (through consensus-building rather than coercion); and (3) mass training of pharmacy supervisors and drug vendors, in the standard treatment of common diseases, be undertaken. This process will be challenging and slow.

Clinical Competence↗
PubMed2001

PROP1 gene screening in patients with multiple pituitary hormone deficiency reveals two sites of hypermutability and a high incidence of corticotroph deficiency.

Alterations of the gene encoding the pituitary transcription factor PROP1 were associated with congenital forms of multiple pituitary hormone deficiencies in several families. Among 23 patients with multiple pituitary hormone deficiencies screened for a PROP1 gene abnormality, nine belonging to eight unrelated families had homozygous PROP1 gene defects. All mutations were located in exon 2 and affected only two different sites: a homozygous AG deletion at codons 99/100/101 (n = 5); homozygous point mutations affecting codon 73: R73C (n = 2) or R73H (n = 1), and a R73C/R99X double-heterozygous mutation (n = 1). R73H and R99X were never described. All patients were born to unaffected parents, and consanguinity was documented in two patients. They had complete GH, LH-FSH, and TSH deficiencies and normal basal levels of PRL. Delayed ACTH deficiency was diagnosed in four of nine patients. At magnetic resonance imaging the anterior pituitary was hypoplastic in seven patients and hyperplastic in two. This study found two novel mutations (R73H and R99X) and underlines the high incidence of PROP1 gene alterations in patients with multiple pituitary hormone deficiencies. A corticotroph deficiency was frequently observed in association with GH, TSH, and gonadotropin deficiencies and should be carefully sought during follow-up.

Adolescent↗
PubMed2001

Combined pituitary hormone deficiency due to the F135C human Pit-1 (pituitary-specific factor 1) gene mutation: functional and structural correlates.

The pituitary-specific transcription factor Pit-1 (pituitary-specific factor 1) is known to play a key role in the differentiation of PRL-, GH-, and TSH-secreting cells, and in the regulation of expression of the corresponding genes. In recent years, 12 distinct mutations of the Pit-1 gene have been shown to be responsible for a phenotype of multiple congenital pituitary hormone deficiency involving PRL, GH, and TSH. We had previously identified, in four siblings with GH, PRL, and TSH deficiencies, a mutation (F135C) resulting in a single amino acid change within the POU-specific binding domain of the Pit-1 molecule. In the present report, we have explored the functional effect of the F135C mutation. In vitro activity tests performed by transfection in human HeLa cells showed decreased transactivation capacity on the PRL, GH, and Pit-1 genes. The DNA binding experiments performed by gel shift showed that the F135C mutation generated a protein capable of binding to DNA response elements. To analyze how the F135C mutation might affect functionality of the transcription factor despite a normal DNA binding, we used a structure modelization approach and also analyzed two other Pit-1 mutant proteins (F135A and F135Y). The loss of functionality in these two mutants was similar to that of F135C. This finding was in keeping with our molecular modeling studies. According to structural data derived from the crystallographic analysis of the DNA/Pit-1 POU domain complex, the conformation of the first helix of the F135C-mutated POU-specific domain could be perturbed to such an extent that any interaction with other transcription cofactors might be definitively prevented.

Amino Acid Sequence↗
PubMed2001

Longitudinal study of fatty acids in plasma and erythrocyte phospholipids during pregnancy.

AIM: To assess the modifications of the main fatty acids (FA) in plasma and red blood cells during pregnancy. METHODS: A longitudinal study of 36 normal pregnant women was carried out with 3 cut-off points: first trimester, second trimester and third trimester. 14 FA in plasma and erythrocyte phospholipids were measured using capillary gas chromatography. Measurements were expressed in percentages and in absolute values. RESULTS: In plasma there was a significant increase in the proportion of saturated FA and a decrease in the proportion of long chain polyunsaturated fatty acids (PUFA) both in the omega 6 (omega 6) and omega 3 (omega 3) series. On the other hand, in erythrocyte phospholipids there was a decrease in the proportion of eicosapentaenoic acid and an increase in that of docosahexaenoic acid. In the omega 6 series, dihomo-gamma-linolenic acid increased, whereas the omega 6 docosapentaenoic acid decreased. CONCLUSION: There was a significant decrease in the proportion of omega 3 PUFA in plasma from the first to the third trimester. Thus, it is suggested that the omega 3 PUFA intake during pregnancy should be increased in the last trimester.

8,11,14-Eicosatrienoic Acid↗
PubMed2001

[Burkitt lymphoma of the cavernous sinus. Apropos of a case].

Cavernous sinus lymphoma is a rare occurrence. We report a case of a 37-year-old woman who was admitted for an oculo-motor paresis and retro-orbital pain. CT scan and MRI disclosed a cavernous sinus tumor. A surgical biopsy was performed through a pterional approach and the histological diagnosis was a solitary primary Burkitt's lymphoma. Aggressive chemotherapy led to a complete and asymptomatic remission after a follow-up of 9 years. The mechanism of the primary localization in the cavernous sinus is discussed.

Adult↗
PubMed2000

Recent advances in the diagnosis and treatment of precocious puberty.

In the last two decades, the diagnosis and treatment of precocious puberty has undergone important changes. The use of supersensitive assays to determine gonadotropins and gonadal hormones has increased the sensitivity and decreased the number of blood samples required to assess the diagnosis. The introduction of gonadotropin-releasing hormone (GnRH) agonists produced a revolution in the diagnosis and treatment of this disorder. Recently, the use of long acting GnRH agonists improved the adherence of patients to medical treatment and decreased the need for uncomfortable repeated doses. The medications in the treatment of the GnRH independent causes of precocious puberty, and the important revelations in the pathophysiology of these disorders, have advanced our knowledge and management of the affected children.

Adolescent↗
PubMed2000

EPR characterization of mono(thiosemicarbazones) copper(II) complexes. Note II.

Copper(II) complexes with thiosemicarbazones have been shown to be more active in cell destruction, in the inhibition of DNA synthesis than the uncomplexed ligand. Several derivatives of thiosemicarbazones and their iron and copper complexes have been studied for their cytotoxicity and inhibiting activity against DNA synthesis. In the present work complexes formed in H2O-DMSO solution between copper(II) and the acetophenone thiosemicarbazone (ATSC) and the o-aminobenzaldehyde thiosemicarbazone (o-NH2TSC) have been studied. EPR studies have been performed at different pH values and metal-to-ligand ratios. The spectra have been recorded at both room (298 K) and low temperatures (120 K). A possible relationship between structure and activity is attempted on the basis of the EPR data.

Antineoplastic Agents↗
PubMed2000

The independent and combined effects of physical and sexual abuse on health. Results Of a national survey

Background: Although physical and sexual abuse have been linked to health risk behaviors as well as mental health problems, it is unclear whether those young women who have experienced both physical and sexual abuse are at greatest risk. To examine the independent associations between physical, sexual, and/or both types of abuse and health status, mental health, and health risk behaviors among a national school-aged sample of girls. We hypothesized that the magnitude of risk would be highest for those reporting both types of abuse compared to those reporting neither or one type of abuse. Methods: In 1997, 3,015 girls in grades 5 through 12 participated in the Commonwealth Fund Adolescent Health Survey and responded to both questions inquiring about physical and sexual abuse. This sample was derives from a nationally representative cross-section of 265 public, private, and parochial schools with an oversampling of 32 urban schools to obtain ethnic diversity. Data were analyzed using chi-square and binary or multinomial logistic regression stratified by type of abuse (none, physical abuse, sexual abuse, or both). Results: About 8% (n = 246) of girls reported a past history of only physical abuse, 5% (n = 140) reported only sexual abuse, and 5% (n = 160) reported experiencing both physical and sexual abuse. Logistic regression controlling for demographic characteristics (grade level, ethnicity, family structure, and socioeconomic status) found those who reported both types of abuse as compared to those who did not report any abuse were significantly more likely to experience moderate-to-severe depressive symptoms (OR = 5.1), moderate to high life stress (OR = 3.3), history of bingeing and purging behavior (OR = 4.4), regular smoking (OR = 5.9) regular drinking (3.8), illicit drug use in the past 30 days (RR = 3.5) and fair to poor health status (OR = 1.9). In contrast, lowered adjusted odds ratios (1.8-2. 5) were seen for those reporting one type of abuse as compared to no abuse across most health outcomes.Conclusions: Those experiencing any type of abuse are at risk; however, those adolescent females who report both physical and sexual victimization are at much greater risk.

Journal Article↗
PubMed2000

Postmortem neuropathological features secondary to boron neutron capture therapy for glioblastoma multiforme.

This postmortem study of 12 patients with glioblastoma multiforme (GBM) treated with boron neutron capture therapy (BNCT) employing an epithermal neutron beam and p-boronophenylalanine describes the neuropathological findings in patients receiving a relatively high radiation dose to the tumor, but a relatively low radiation dose to the normal brain. In addition to a standardized neuropathology panel of sections, we used individual treatment dosimetry maps to select sections along the projected maximum radiation beam pathway. We found that the normal neuroparenchyma exposed to the highest radiation dose exhibited a single instance of radiation-induced focal venular fibrinoid necrosis and a single instance of multifocal demyelination. Semiquantitative analysis of pretreatment neurosurgical and postmortem tumor samples revealed only two radiation ascribed histopathological findings to be particular to therapy, fibrinoid necrosis and vascular hyalinization. In this relatively small series of cases we found an unexpectedly high frequency of cases (3 of 12) with neurodegenerative histopathology (Lewy bodies, neurofibrillary tangles, and neuritic senile plaques), which appeared, by distribution, to be independent of the radiation beam. Two of these patients were over 70 yr of age. One was only 41. Our findings suggest an acceptable radiation-induced level of neurotoxicity at the lower doses employed, but raise the possibility of unexpected boron neurodegenerative toxicity.

Adult↗
PubMed2000

Autoradiographic evidence of delta-opioid receptor downregulation after prenatal stress in offspring rat brain.

In order to visualize neuroanatomical alterations in specific brain regions, light microscopy autoradiography was carried out on offsprings (postnatal day 10) from female rats stressed in different periods of gestation and controls. Group 1 was subjected to restraint stress from day 2 to 6; group 2, from day 7 to 11; group 3, from day 12 to 16; group 4 from day 2 to 16. Group 2 showed decreases in delta-opioid receptor density in different hypothalamic regions. The decrease in delta-opioid receptor density was less marked in groups 1 and 3 whereas there was no modification in group 4. Present data suggest that the prenatal stress induces a downregulation of delta-receptors in different hypothalamic regions.

Animals↗
PubMed2000

[Dermoid cyst of the lateral ventricle associated with ethmoidal dermal sinus. Report of a case].

We report a case of a ventricular dermoid cyst associated with a dermal sinus connected with the ethmoidal cells in a patient who developed rapid symptoms of raised intracranial pressure. Computed tomography showed a cystic mass in the right lateral ventricle with a hydrolipidic image in the left frontal horn of the ventricle and associated hydrocephalus. Magnetic resonance imaging showed a heterogeneous T1 hyperintense mass with a fistulous tract communicating with the ethmoid cells. A cerebrospinal fluid ventriculo-peritoneal shunt was initially established, which required further revision. A right sided transventricular approach was undertaken in a second stage, allowing resection of a dermoid cyst. Obliteration of the dermal sinus tract was obtained using pericranial duraplasty. Clinical and imaging features are discussed. The need for total resection including the tumor capsule and occlusion of the fistula are emphasized if recurrence and infection are to be prevented.

Adult↗
PubMed2000

Pretreatment prostate-specific antigen and Gleason score predict the risk of extracapsular extension and the risk of failure following radiotherapy in patients with clinically localized prostate cancer.

The purpose of this study is to evaluate the use of a relatively simple equation for predicting the risk of extracapsular extension (ECE) based on the pretreatment prostate-specific antigen (PSA) and Gleason score (GS) in patients with clinically localized prostate cancer. Three hundred and seventy-four patients who underwent radical prostatectomy between 1988 and 1994 and 521 men undergoing definitive radiotherapy during a similar time period were eligible for this analysis. Surgically treated patients were considered eligible if the pathological stage, preoperative PSA, and GS were available. Among these patients, the median preoperative PSA was 8.1 ng/mL (range, 0 to 195 ng/mL), and the median preoperative GS was 6 (range, 2 to 10). The empirically derived equation tested was (1.5 x PSA + [GS - 3] x 10). For this equation, the range of calculated risk was limited to 0% to 100%. Using the empirically derived equation, patients with a low calculated risk (CR) of < or = 33% had an average calculated risk (ACR) of 21.9% and an observed incidence (OI) of ECE was 17.8%. Patients with a moderate CR of 34% to 66% had an ACR of 46.3%, and an OI of ECE was 46.7%. Patients with a CR of 67% to 100% had an ACR of 83.7% and an OI of ECE of 66.7%. Of the 21 patients who had a PSA < or = 4 and a GS < or = 4, only 1 patient (4.8%) was found to have ECE. Men with an estimated risk of ECE of <33%, 33% to 67%, and >67% had a 4-year risk of biochemical failure following radiotherapy of 29%, 56%, and 78% (P < .00001). This empirically derived data appears to be reasonably accurate at estimating the incidence of ECE in patients with at low or intermediate risk before surgery. The risk of biochemical failure following radiotherapy also correlated the risk of ECE. Future staging systems for prostate cancer should use similar approach for defining risk groups.

Biopsy↗
PubMed2000

[Pituitary development and pathology of transcription factors].

Over the last 10 years, important data on pituitary development have been reported using spontaneous or experimental models of gene inactivation. The development pathways of the anterior pituitary lobe include organogenesis resulting in Rathke pouch formation and cell differentiation. Pituitary development is controlled by sequential series of specific signaling molecules and specific transcription factors. In humans, inactivation of Pit-1, Prop-1, Rpx and Ptx2 genes is responsible for pituitary combined deficiency. In this paper, updated data on the embryology of the pituitary gland and the clinical phenotypes of inactivation of pituitary transcription factors are reported.

Animals↗