Search PubMed⌕ Search

Biomedical subjects

C Diaz

Publications and source records attributed to C Diaz.

At least 91 records · Page 5Linked to original sources
PubMed1995

[Peritoneal dialysis in cases of associated pathology].

There are two aspects to considerations of the value of peritoneal dialysis (PD) in the treatment of renal insufficiency with associated pathology. The first involves the effects of the treatment on the symptoms or evolution of the pathology. Examples include the improvement of dyspnea due to cardiac insufficiency (CI) and of cirrhotic ascites (CA). However, there is also an undefined risk of reactivation lupus. The second facet is the increased risk of peritoneal infection, particularly for patients who are HIV + or who are immunosuppressed due to lupus or myeloma. In certain types of case (lupus with intractable vascular thrombosis, intolerance of ultrafiltration in cases of CI, AC or generalised amyloidosis) PD has particular advantages. Nevertheless, there has been no appropriate prospective study to demonstrate or otherwise the advantages in terms of survival. The use of PD remains therefore a matter of choice for individual patients and experienced health care team.

HIV Infections↗
PubMed1995

[Effect of protein and carbohydrate preloads on food and energy intakes in preschool children with different nutritional status].

Three preloads: high in simple carbohydrates (fruit juice), high in complex carbohydrates (banana) and high in protein (chicken meat), were tested in two groups of preschool children (56), aged 2 to 4 years from both genders. One group had a normal weight for height and the other high weight for height. The preload were given thirty minutes before lunch. The lunches consisted in a legume dish, apple and a milk dessert. Children were stimulated but not forced to eat and the amount of foods consumed was determined by differential weighing. The results showed that overweight children had a lower consumption at lunch that normal children when the high carbohydrate preloads were tested. High simple carbohydrate preload, 338,2 +/- 87.0 vs 350,9 +/- 75.9, high complex carbohydrate preload, 336.2 +/- 109.6 vs 375.4 +/- 89.4. High protein preload had not effect on the lunch consumption in the two groups of children studied. When an analysis by age of children were made, dividing the normal and overweight children in two groups, 24 to 36 months and 36 to 48 months, it was demonstrated that differences in lunch consumption between the normal and overweight children was derived essentailly from the results obtained in children of 24 to 36 months, high simple carbohydrate preload 282.3 +/- 88.9 g vs. 318.5 +/- 80.0 g and in the high complex carbohydrate preload, 262.6 +/- 98.9 g vs 364.5 +/- 116.3 g. When energy intake derived from food consumption was analyzed, the same tendency described for food consumption was demonstrated. The results presented show a different response of overweight children to the high carbohydrate preloads consumed before lunch, specially in children aged 24 to 36 months. This findings are important since they give an experimental information that can be utilized to find metabolic answers in relation to the onset of obesity in the childhood and to establish dietary recommendations in order to alleviate the risk of obesity in children.

Analysis of Variance↗
PubMed1994

Blood culture in the first 6 months of life for the diagnosis of vertically transmitted human immunodeficiency virus infection. The Women and Infants Transmission Study Group.

Serial blood cultures over the first 6 months of life in 310 infants with vertical exposure to human immunodeficiency virus (HIV) in the Women and Infants Transmission Study were analyzed to determine their value for early diagnosis of HIV infection. Cultures were done at 0-7 days and 1, 2, 4, and 6 months of age: 55 infants were infected. Blood culture sensitivity in infected children was 24% (7/29) during the first week of life and 85%, 91%, 82%, and 88%, respectively, at 1, 2, 4, and 6 months. The sensitivity, specificity, and positive and negative predictive values of a single culture between 1 and 6 months of age were, respectively, 86.9%, 99.6%, 97.9%, and 97.5%. Two negative cultures between 1 and 6 months of age defined an uninfected infant with a specificity of 99.2%-100.0%. Blood culture done between 1 and 6 months of age in children of HIV-positive mothers is a sensitive and specific test for HIV infection, with high positive and negative predictive values.

Blood↗
PubMed1994

Posttransfusion and community-acquired hepatitis C in childhood.

Following a longitudinal study of chronic non-A, non-B hepatitis in Italy and Spain, we evaluated the epidemiologic and clinical features of chronic hepatitis C in 77 consecutively observed children (35 male; mean age, 4 years) without underlying systemic diseases. All subjects were positive for antibody to hepatitis C virus in serum by second-generation tests. Forty-six patients had received blood transfusions in the perinatal period; 12 had a mother with antibodies to HCV in serum (five of these mothers were drug users or partners of a drug user); seven had a history of putative percutaneous exposure; and 12 had not been exposed to any risk factors for viral hepatitis. At presentation, only 22% were symptomatic, mean alanine-aminotransferase levels were three times the upper normal value, and liver histology showed active disease in only nine of 28 cases (32%). During a mean observation period of 6 years, only 11 of 57 patients (19%) complained of symptoms and 11 of 40 cases (27%) had histologic features of active hepatitis. Two patients had severe hepatitis with associated cirrhosis. However, only six of 57 cases (10%) achieved sustained biochemical remission. The clinical features and the outcome were similar in both the posttransfusion and the community-acquired cases. These results indicate that transfusions in the perinatal period are the single most important cause of hepatitis C in otherwise healthy children. Community-acquired cases represent an heterogeneous epidemiologic group in which maternal transmission, whether perinatal or postnatal, could be relevant.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1993

Effectiveness and costs of digoxin treatment for atrial fibrillation and flutter.

Clinical outcomes and costs associated with the use of digoxin in atrial fibrillation and flutter were evaluated in a prospective, observational study at 18 academic medical centers in the United States. Data were collected on 115 patients (aged > 18 years) with atrial fibrillation or flutter who were treated with digoxin for rapid ventricular rate (> or = 120 beats/min). The median time to ventricular rate control (i.e., resting ventricular rate < 100 beats/min, decrease in ventricular rate of > 20%, or sinus rhythm) was 11.6 hours from the first dose of digoxin for all evaluable patients (n = 105) and 9.5 hours for those only receiving digoxin (n = 64). Before ventricular rate control, the mean +/- SD dose of digoxin administered was 0.80 +/- 0.74 mg, and a mean of 1.4 +/- 1.8 serum digoxin concentrations were ordered per patient. Concomitant beta-blocker or calcium antagonist therapy was instituted in 47 patients (41%); in 19 of these, combination therapy was initiated within 2 hours. Adenosine was administered to 13 patients (11%). Patients spent a median of 4 days (range 1 to 25) in the hospital; 28% spent time in a coronary/intensive care unit and 79% in a telemetry bed. Loss of control (i.e., resting ventricular rate returned to > 120 beats/min) occurred at least once in 50% of patients and was associated with a longer hospital stay (p < 0.05). Based on 1991 data, the estimated mean hospital bed cost for patients with atrial fibrillation or flutter was $3,169 +/- $3,174.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Rostrocaudal changes in neuronal cell size in human lateral vestibular nucleus.

A cytoarchitectonic and morphometric study of the human lateral vestibular nucleus (LVN) is presented. In sagittal sections, the LVN appears as a triangular cell group rostrally located near the motor trigeminal nucleus and caudally near the vestibular root. The estimated volume is 13.49 mm3 with a neuronal population of 25,046 cells and 1855 neurons/mm3 in density. The average neuronal cross-sectional area changes from a minimum caudally (380.02 +/- 7.23 microns 2) to a maximum rostrally (825.16 +/- 25.10 microns 2). Four types of neurons can be observed: small (< 200 microns 2), medium (200-500 microns 2), large (500-100 microns 2) and giant or Deiter's cells (> 1000 microns 2). The small and medium cells constitute 62%, large cells 26% and the giant cells only 12% of the neuronal population.

Adult↗
PubMed1993

Cell-type specific expression of three rice genes GOS2, GOS5 and GOS9.

The cell-type-specific expression of three rice genes, GOS2, GOS5 and GOS9, was studied by mRNA in situ hybridization. Previous northern blot analysis revealed that these genes were constitutive, green tissue-specific and root-specific, respectively. In this study, GOS2 transcripts were observed in all leaf cell types. In roots, a temporal and spatial expression pattern was noticed. Higher mRNA levels were observed in lateral roots, especially in parenchymal cells of the vascular cylinder. Expression of GOS5 was mainly found in chloroplast-containing cells. For GOS9, significant levels of signal were observed in root and leaf sections.

Gene Expression Regulation↗
PubMed1993

Neck dissection with or without postoperative radiotherapy in supraglottic carcinomas.

A retrospective review of 302 previously untreated patients with primary supraglottic carcinoma was undertaken to ascertain the efficacy of postoperative radiotherapy. The 302 patients underwent a total of 383 functional neck dissections and 45 classic radical neck dissections. Pathological examination revealed nodal involvement in 117 patients (39%). In the histologically N0 group, the incidence of contralateral neck recurrence when a unilateral neck dissection and postoperative radiotherapy were carried out was 8%, rising 21% when no postoperative radiation was given. There was no difference in the ipsilateral recurrence rate in the N0 group, radiated patients (3%) and nonradiated patients (2%). Similar figures were found in the N1 group. Bilateral functional neck dissection in histologically N0, N1, and N2 necks had similar recurrence rates with or without radiotherapy. Distant metastasis appeared in 10% of N0 patients and in 35% of N3 patients. Patients who received postoperative radiotherapy showed a significantly higher rate of distant metastasis (21%) than patients who did not (8%). The number of involved lymph nodes had no relevance both in neck recurrence and distant metastasis.

Carcinoma↗
PubMed1992

Thymosin alpha 1 is a native peptide in several tissues.

Failure to detect thymosin alpha 1 (T alpha 1) in tissue extracts prepared by procedures that prevent proteolytic activity has hitherto supported the suggestion that T alpha 1 is not a natural peptide, but the product of uncontrolled proteolysis of prothymosin alpha (ProT alpha), a polypeptide that includes T alpha 1 at its NH2 terminus. In this work, purification by isoelectric focusing of a product with the same isoelectric point as synthetic T alpha 1, and its further characterization, demonstrated that T alpha 1 is present as a native peptide in calf thymus and in several lymphoid and non-lymphoid rat tissues. T alpha 1 shows abnormal chromatographic behaviour which appears to be due to association with other components in tissue extracts. In all the tissues studied, T alpha 1 was present in higher concentration than ProT alpha (80-183 and 44-123 micrograms per gram of tissue, respectively). The ProT alpha/T alpha 1 ratio did not change when no measures were taken to prevent proteolysis during tissue homogenization.

Animals↗
PubMed1992

Analysis of the tissue distribution and inheritance of heteroplasmic mitochondrial DNA point mutation by denaturing gradient gel electrophoresis in MERRF syndrome.

MERRF (Myoclonic Epilepsy and Ragged-Red Fibres) syndrome is one of the maternally inherited diseases for which a mitochondrial DNA (mtDNA) point mutation has recently been identified. The mutation is always heteroplasmic, that is normal and mutant mtDNA coexist within the same individual. We studied mtDNA heteroplasmy in two families with MERRF syndrome, using a denaturing gradient gel electrophoresis technique that avoids the errors in the evaluation of wild/mutant mtDNA ratios caused by restriction enzyme cutting in the situation of amplification of a heteroplasmic DNA. In two patients, the proportion of muscle mutant mtDNA was in agreement with the severity of muscle mitochondrial proliferation, energy defect and fibre type I predominance. In nine patients from three generations of one family, mutant mtDNA proportion in leukocytes was in relative agreement with the clinical severity of the disease. Transmission of mutant mtDNA through these three generations did not show any tendency toward homoplasmy. Homogeneity of the mutant mtDNA proportion among different tissues from one patient was demonstrated in brain, liver, muscle and heart but a possibility of divergence of the mutant mtDNA proportion during mitosis was documented in cultured skin fibroblasts.

Adolescent↗
PubMed1992

N-cadherin and N-CAM in myoblast fusion: compared localisation and effect of blockade by peptides and antibodies.

The expression and distribution of two cell adhesion molecules, N-cadherin and N-CAM, at the surface of cultured leg muscle cells from 11-day-old chicken embryos were studied and compared. N-cadherin, which was expressed by fusing myoblasts, was down-regulated on old myotubes while N-CAM was still present. Both molecules, as viewed by confocal microscopy, appeared to have coaccumulated at the areas of contact between fusing myoblasts. However, immunogold electron microscopy did not reveal significant colocalization of N-cadherin and N-CAM, and their segregation after antibody-induced patching suggested the absence of direct interactions between N-cadherin and N-CAM. The role of the Ca2+ dependent cell adhesion molecule N-cadherin in myogenesis was investigated. Myoblast fusion was inhibited (1) with a synthetic peptide containing the H-A-V sequence and (2) with a monoclonal anti-N-cadherin antibody, demonstrating that N-cadherin-mediated cell adhesion is required for myoblast fusion. Under the same conditions no effect of anti-N-CAM antibodies was observed. Taken together these observations suggest that N-cadherin, acting independently from N-CAM, is a major cell adhesion molecule involved in embryonic myoblast fusion in vitro.

Amino Acid Sequence↗
PubMed1992

Relationship between milk expected progeny differences of polled Hereford sires and actual milk production of their crossbred daughters.

One hundred sixteen spring-calving Polled Hereford x Angus cows were milked using milking machines after receiving 20 IU of oxytocin. Sires of the cows had been divergently selected on yearling weight (YW) and total maternal (MAT) EPD to form four groups: high YW, high MAT EPD; high YW, low MAT EPD; low YW, high MAT EPD; and low YW, low MAT EPD. Average milk production after 12-h calf separation was 3.7 +/- 1.3 kg. Actual milk production of cows was regressed on their sires' milk EPD, where the milk EPD estimates the additive maternal genetic contribution of a sire to the weaning weight of his daughters' calves. The regression of actual 12-h milk production on sire milk EPD was .038 +/- .014 kg/kg, and the correlation was .26 (P less than .006), close to its expected value, based on the accuracy of the prediction, heritability of the trait, and the relationship between sire and daughter. Extension of results of a single milking to an entire lactation is difficult, but over the range of sire milk EPD sampled (-10 to 16 kg), the range in daughters' milk production predicted from the regression analysis was 27% of the mean actual milk production, corresponding to an increase of about 1% more milk per kilogram of milk EPD.

Animals↗
PubMed1992

An improved polymerase chain reaction assay to detect Trypanosoma cruzi in blood.

Amplification by the polymerase chain reaction of Trypanosoma cruzi satellite DNA was used to enhance sensitivity in the detection of the parasite in blood, with the ultimate goal of improving diagnosis of the chronic phase of Chagas' disease. Two contiguous oligonucleotides were synthesized corresponding to the most conserved region of the 195-basepair repeated sequence and used as primers for the amplification reaction. Nineteen femtograms of parasite DNA that was amplified in the presence of 15 micrograms of human or mouse DNA produced a visible band upon electrophoresis in agarose gels and staining with ethidium bromide. In reconstitution experiments, one parasite in 10 ml of blood could be unambiguously determined when the DNA was isolated from nuclei after the blood was treated with NP40 and centrifuged. Polymerase chain reaction assays were carried out to detect T. cruzi in chronically infected mice. Most mice were parasite-positive when organs or tissues were tested, but all were negative when total blood was tested.

Animals↗