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Biomedical subjects

P Ballesteros

Publications and source records attributed to P Ballesteros.

At least 19 recordsLinked to original sources
PubMed1995

[Pseudomyxoma peritonei].

Pseudomyxoma peritonei is an infrequent clinical entity, characterized by peritoneal implantations organized in cyst of mucine or free peritoneal mucine. Most arise from cystadenoma or cystadenocarcinoma of the ovary and appendix, and fewer from other tumours and locations. It is more common in females, and it is usually diagnosed over the fifth decade. Three cases of pseudomyxoma peritonei are presented, two associated to appendicular carcinoma and one to carcinoma of the ovary, and the data published about this disease are reviewed.

Aged↗
PubMed1994

[Emergency hospital admission in medical services: causes, justification, social factors, and their differences in function of age].

BACKGROUND: Increasing attention has been given to the care to elderly patients in emergency departments (ED). Moreover, few data are available about final phase of the process, that is hospital admission from ED. This study was conducted to establish appropriateness, reasons and social factors related to hospital admission in medical services from ED and their age-related differences. METHODS: The Appropriateness Evaluation Protocol scale (AEP) was applied prospectively to 515 patients 15 years and older admitted to medical services through an ED. Patients who did not meet any AEP criteria were evaluated for other medical or social factors as conditions for their admission. RESULTS: The sample was composed by 303 elders (65 years and older, mean age = 77 +/- 6 years) and 212 adults (15-64 years old, mean age = 45 +/- 14). 271 elderly patients (89.4%) and 173 adults (81.6%) meet AEP criteria (p = 0.01). Hospitalary admission for diagnostic procedures is more frequent in younger than in older group (14.2% versus 6.9%, p = 0.01). No differences are detected in hospital admissions based upon strictly social factors: 7 (2.3%) in elderly group and 7 (3.3%) in younger one (p = 0.05). CONCLUSIONS: Urgent hospital admissions in medical services are justified more frequently in elderly patients. These patients are admitted for diagnostic procedures less frequently than younger group. No age-dependent difference in strictly social admissions is detected.

Age Factors↗
PubMed1994

Imidazol-1-ylalkanoic acids as extrinsic 1H NMR probes for the determination of intracellular pH, extracellular pH and cell volume.

The synthesis and biological evaluation of a novel series of extrinsic probes for intracellular pH (pHi), extracellular pH (pHo) and cell volume determination by 1H NMR is described. Imidazol-1-ylacetate, malonate, 3-glutarate and 2-succinate esters were synthesized by reaction of imidazole with alpha-bromo esters or with alpha, beta-unsaturated esters. The corresponding acids were prepared by hydrolysis. Rat erythrocytes were readily permeable to methyl imidazol-1-ylacetate, moderately permeable to diethyl 2-imidazol-1-ylsuccinate and impermeable to diethyl 3-imidazol-1-yl-glutarate esters. Imidazol-1-ylacetic acid was the only acid derivative which penetrated the erythrocyte interior when added directly to the incubation medium. Transport of the permeable compounds to the erythrocyte interior was non-saturable up to 200 mM added compound. Addition of methyl imidazol-1-ylacetate or diethyl 2-imidazol-1-ylsuccinate esters to erythrocyte suspensions, resulted in hydrolysis to imidazol-1-ylacetic acid and 2-imidazol-1-ylsuccinic acid mono-ethyl ester in the intracellular and extracellular spaces, respectively. pHi and pHo were determined from the different chemical shifts of the H-2 proton of the acid derivatives in the intracellular (H-2i) and extracellular (H-2o) compartments. In addition, the relative intracellular and extracellular volumes could be calculated from the areas of the intracellular and extracellular H-2 resonances.

Animals↗
PubMed1992

Alternating chemotherapy for small-cell lung cancer. A twelve-week schedule of six drugs.

We have treated sixty-two patients (21 with limited disease, 41 with extensive disease), on an outpatient-basis schedule of six drugs administered weekly for twelve weeks. Cyclophosphamide, 400 mg/m2, adriamycin, 20 mg/m2 and vincristine, 2 mg, full dose, were administered during weeks 1, 5 and 9; cisplatin, 50 mg/m2 and etoposide, 100 mg/m2 during weeks 2, 6 and 10; adriamycin and vincristine at the same doses during weeks 3, 7 and 11; methotrexate 30 mg/m2, during weeks 4, 8 and 12. After the first 28 patients vincristine was replaced by teniposide (VM-26) due to neurotoxicity. The overall response rate was 64.5% (complete remission 13 p., partial remission 27 p.). Toxicity grade 3-4, mainly nausea and vomiting or neutropenia, was recorded in 17 patients. Alopecia grade 1-2 was universal. One toxic death occurred from sepsis. The overall survival was 8 months (range 1-40), (95% CL: 53-77%); 8 months in limited disease (range 1-40), and 7 months in extensive disease (range 1-23). Time to treatment failure was 6 months (7 limited disease, 5 extensive disease). In conclusion, the results of this alternating schedule are poorer than those attained with standard, high-dose treatments, mainly in limited disease, but could be a less toxic option for patients with extensive disease.

Adult↗
PubMed1992

[Myopathy and zidovudine].

BACKGROUND: The aim of this study was to evaluate the frequency of appearance of myopathy in a group of patients treated with zidovudine. METHODS: A prospective study of 37 patients with positive serology for HIV treated over 180 days with zidovudine was carried out with evaluation of the clinical history, physical examination and analytical data. RESULTS: The initial mean value of creatine kinase of 76.4 U/l and 83.3 U/l following 6 months of treatment was not statistically significant. Of the 37 patients, 2 (5.4%) showed no variations in CK values, while in 4 (10.8%) there was a decrease and in 30 (81%) an increase. There was an elevation in 11 of the 15 patients (73%) who received doses equal to or lower than 90 g, 11 out of 13 (84.6%) of those who received between 90 and 145 g and 8 out of 8 (100%) of those having received doses higher than 145 g. This increase was minimum in 27 cases (92%) and important with final values of pathologic CK in 3 (8%). Two patients (5.4%) developed clinical manifestations. CONCLUSIONS: Not only the frequency and range of creatine kinase elevation but also the appearance of clinical manifestations in this study are lower than those found in the literature, probably because of the relation with the use of lower doses of zidovudine. These results do not demonstrate any relation with sex, age, risk group for the immunodeficiency status.

Acquired Immunodeficiency Syndrome↗
PubMed1992

[Spontaneous pneumothorax and Pneumocystis carinii pneumonia. Something more than a casual association?].

The association of spontaneous pneumothorax and Pneumocystis pneumonia is not frequent. The medical literature reports a ratio between 0 and 5.7%. In 18 patients admitted in our hospital, in the last two years, and diagnosed of AIDS and Pneumocystis pneumonia, we observed two cases of pneumothorax spontaneous. They represent the 11%. In one of them spontaneous pneumothorax was the first manifestation and in the other a complication of the illness. It was not possible to isolate an agent different from Pneumocystis carinii. Considering the lack of predisposition factors and the previous clinical history, we think that Pneumocystis carinii is by itself the agent responsible of this complication. In view of this possibility, spontaneous pneumothorax in a patient who belongs to an AIDS' risk group will alert the clinician to the possibility of infection with Pneumocystis carinii.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Pyruvate decarboxylating action of L-cycloserine. The significance of this in understanding its metabolic inhibitory action.

We present evidence which demonstrates that L-cycloserine, structural analog of L-alanine, which is known to be an effective aminotransferase inhibitor, is also a potent inhibitor of cellular pyruvate metabolism. This effect was found to be related to its almost instantaneous action in decreasing pyruvate concentrations in a dose-dependent manner. 1H nuclear magnetic resonance studies clearly demonstrate that the irreversible removal of pyruvate induced by L-cycloserine is caused by the decarboxylating action of the latter. Pyruvate disappearance induced by L-cycloserine can be stoichiometrically accounted for as acetate. The process does not involve any chemically detected transformation of L-cycloserine. These observations lead to two main considerations regarding the known action of L-cycloserine. First, its inhibitory effect on gluconeogenesis from lactate could be explained only on the basis of its ability to reduce pyruvate availability with no apparent need for transaminase inhibition. Second, its ability as a transaminase inhibitor should be reconsidered in view of its potent decarboxylating action on pyruvate and probably other oxoacids.

Animals↗
PubMed1983

Synthesis and transport applications of 3-aminobicyclo[3.2.1] octane-3-carboxylic acids.

The isomeric 3-aminobicyclo[3.2.1]octane-3-carboxylic acids were synthesized and compared with the widely used (1R,2S,4S)-2-aminobicyclo[2.2.1]heptane-2-carboxylic acid as to specificity to the Na+-independent membrane transport system L of the Ehrlich ascites tumor cell and of the rat hepatoma cell line HTC. The presence of an additional methylene group in the ring system leads to an optically symmetrical amino acid, with the advantages that the product is devoid of isomeric contamination. Hence, optical resolution is not necessary to secure a homogeneous test substrate for discrimination of amino acid transport systems. Through its inhibitory action on the cellular uptake of known system-specific amino acids, the bicyclo[3.2.1]octane amino acid proved more reactive than the bicycloheptane analogue with the Na+-independent amino acid transport system of the test cells and not perceptibly reactive with the accompanying Na+-dependent systems. Recent evidence of the presence of a second component of Na+-independent amino acid transport, beyond system L, increases the importance of securing a variety of possibly discriminatory model substrates.

Amino Acids↗
PubMed1983

Psychological evaluation of intensive care nurses.

To understand the possible psychological repercussions of working in an ICU, we report on 18 nurses in our unit, who took the Minnesota Multiphasic Personality Inventory (MMPI), the Rorschach test, and two prints from the Phillipson test. Each nurse took these tests during her 1st month of work and again at 12 months; 9 repeated the tests once more 24 months after entering the ICU. The results demonstrated the absence of clinical evidence in all cases. Findings of the Rorschach indicate that the larger part of the group use defense mechanisms to confront the numerous harmful stimuli and the high level of anxiety. In spite of this, the Phillipson test shows approximately one-half of them to manage depressive situations correctly and formulate solutions and mechanisms of reparation.

Adaptation, Psychological↗
PubMed1981

Effect of diphenylhydantoin, granatane-3-spiro-5'-hydantoin and leptazol on mouse brain glutamate dehydrogenase, urea and ammonia levels in brain.

The effect of diphenylhydantoin (DPH), granatane-3-spiro-5'-hydantoin and leptazol has been checked on both GDH activity and ammonia and urea levels in brain. Concentrations of 90 mg/kg of leptazol decreased, significantly, the ammonium and urea levels in brain with respect to normal control. DPH and G-3SH had no effect on these metabolites against normal control. The association of DPH and leptazol decreased both urea and ammonium levels in brain but the association of G-3SH and leptazol decreased, significantly, urea levels but not ammonium's. DPH, leptazol at 90 mg/kg concentration and the association of DPH or G-3SH with leptazol had no significant effect on GDH activity while G-3SH increased the enzyme activity when it was measured in the direction of glutamate degradation. DPH, G-3SH and both concentrations of leptazol decreased the GDH activity when it was checked in the direction of glutamate synthesis. The association of DPH and leptazol did not produce any effects, while the association of G-3SH-leptazol increased the enzyme activity. DPH and G-3SH and leptazol at 110 mg/kg concentration decreased the relation of GDH activity between the biosynthetic and degradative sense. The association of G-3SH-leptazol increased this relation while leptazol and its association with DPH did not affect it.

Ammonia↗