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Biomedical subjects

A Lopez

Publications and source records attributed to A Lopez.

378 records · Page 21Linked to original sources
PubMedDate not supplied

[Determination of blood alcohol among aviation personnel: proposed operative protocol].

The problems of the use/abuse of alcohol need a special attention by the Public Authorities, based on the scientific evidences related to the subject. We would like to define in the present paper the procedures for alcohol testing (and drug testing) in the sailors, following the international aviation authorities (ICAO, JAR-OPS-1, FAA) recommendations. A Working Group was established to study both the scientific and the legal aspects of the problems related to alcohol testing in Italy. Experts from the Università "La Sapienza" and from Alitalia studied the alcohol testing issues abroad to set out criteria, guidelines and procedures for random testing in Italy.

Aerospace Medicine↗
PubMedDate not supplied

Calcitonin reserve and the differentiated response to calcitonin in osteoporosis.

The authors followed up the effect of calcium and calcitonin administration on phosphorus-calcium balance and on calcium retention, in correlation with the level of endogenous calcitonin, in 20 patients of perimenopause age (40-50 years), with radiologically confirmed osteoporosis. Calcium retention after loading with calcium gluconate (180 mg in i.v. injections) was determined before and after administration of salmon calcitonin (100 IV in i.m. injections). Two types of responses were noted. In a group of patients calcitonin administration determined a rise of calcium retention at the same time with the improvement of other biochemical parameters as well as a normal calcitonin response. The presence of high levels of circulating calcitonin 24h after loading with exogenous calcitonin demonstrated a slower inactivation rate of the hormone in these patients. The other group showed no positive response to calcitonin. The proposed test is a criterion for the selection of the patients with osteoporosis in view of chronic calcitonin treatment.

Adult↗
PubMedDate not supplied

[Semi-automated quantification of MRI high signals observed in multiple sclerosis].

MR T2 Weighted sequences on the brain demonstrate disseminated "high signal zones" (HSZ) in patients with Multiple Sclerosis; these morphological alterations are corresponding to the plaques. From the very beginnings of MR in 1981, everybody recognizes the main importance of this fact. MR appears as the most sensible exploration in patients with M.S. But the signal alteration is not specific; the clinical considerations and the evolution are requested. The aim of this work is to give a reference tool for evolutive evaluation of the disease. A work station with a specially developed software are presented. The HSZ thresholding is partially automatic. The edition of a cerebral mapping is developed. These results are discussed.

Humans↗
PubMedDate not supplied

[Oculomotor paralysis of endocrine origin. The value of x-ray scanning].

The X-ray scanning symptoms of dysthyroidal ophtalmopathy are so typical that they are enough to make the diagnosis in most of cases. Their determination through the FEMEN system increases the sensitivity of the method. The investigation of 60 cases of oculomotor palsies with a FEMEN score greater than 10 confirms that they are certainly or probably subsequent to an endocrinopathy in 93% ot the cases.

Adult↗
PubMedDate not supplied

19F nuclear magnetic resonance analysis of the carbamate reaction of alpha-fluoro-beta-alanine (FBAL), the major catabolite of fluoropyrimidines. Application to FBAL carbamate determination in body fluids of patients treated with 5'-deoxy-5-fluorouridine.

alpha-Fluoro-beta-alanine (FBAL), the major catabolite of the antineoplastic fluoropyrimidines, is an amino acid which is in equilibrium with its carbamate derivative in weakly alkaline aqueous solutions containing carbonate. In both water and control biological fluids (urine, plasma) spiked with FBAL (and sodium bicarbonate, in some cases), 19F NMR was used: (i) to determine the pH range over which FBAL carbamate is present (pH greater than or equal to 7), the maximum concentration formed occurring around pH 9, (ii) to show that the amino group of FBAL interacts very slowly with a non-protein plasma component to form a compound X, unstable in acid medium. The presumed structure of X is RCONHCH2CHFCOOH, with R different from an alkyl group but still unidentified. The behavior of FBAL in urine and plasma of rats treated with FBAL or 5'-deoxy-5-fluorouridine (5'-dFUrd), a prodrug of 5-fluorouracil, and from patients treated with 5'-dFUrd was investigated. FBAL carbamate was not present in acid medium and was therefore absent in acidic human urine. However, it was found in alkaline rat urine. FBAL carbamate was found in plasma along with the compound X. The 19F NMR spectra of FBAL and derivatives are complex since alpha-fluoro-beta-ureido-propionic acid, the precursor of FBAL in the catabolic pathway of antineoplastic fluoropyrimidines, produces a signal overlapping that of FBAL carbamate, and very close to that of compound X.(ABSTRACT TRUNCATED AT 250 WORDS)

Alanine↗
PubMedDate not supplied

Calcitonin secretion in rats with inflammation mediated osteopenia.

The authors followed up the occurrence of inflammation-mediated osteopenia (IMO) in young and adult rats weighing 50 g and 150 g, respectively. The calcemia, the amount of bone calcium and the calcitonin content of the thyroid gland were determined. Calcium loss from bones was similar in both groups, irrespective of age. However, in the young animals a significant rise of calcitonin content of the thyroid gland was found (11.08 ng/ml as compared with 3.81 ng/ml in the controls). In adult animals with IMO the level of calcitonin in the thyroid gland showed no change as compared with the controls. Calcitonin reactive hypersecretion in the young animals was not able to prevent the development of IMO, characterized by an important loss of bone calcium.

Aging↗
PubMedDate not supplied

Liver transplantation with a twenty-four hour delay and an initial low dose of cyclosporine.

BACKGROUND/AIMS: Cyclosporine A based immunosuppression protocols have improved the results of liver transplantation. However, there is no general agreement concerning the most appropriate initial dose of cyclosporine or the precise moment we should start its administration. MATERIALS AND METHODS: Two cyclosporine A administration procedures in liver transplantation were analyzed by means of a prospective study using 91 consecutive patients and dividing them into two groups: Group A: 50 consecutive transplants in which cyclosporine was started since the surgery at 4 mg/kg/day, and Group B: the following 41 consecutive transplants in which cyclosporine was started 24 hours after transplantation at 2 mg/kg/day. RESULTS: Cyclosporine levels were higher in Group A in the first month (without significant differences). There were differences in the need for hemodialysis (14% vs 0%, p < 0.01), in the length of time (h) on mechanical ventilation (147.5 +/- 36 vs 48.7 +/- 15.7, p < 0.05) and in the time (d) spent in intensive care (10.5 +/- 1.6 vs 6.5 +/- 0.8, p < 0.05). There were no differences in the incidence of acute rejection, arterial blood pressure, septic and neurological complications, or in the actuarial survival rate for patients and grafts at 36 months. CONCLUSIONS: Delayed administration of cyclosporine simplifies the treatment of patients in the first 24 hours, it has several beneficial features and does not appear to be associated with a high acute rejection rate. On the basis of these results, our group has adopted delayed and low-dosage cyclosporine procedure.

Creatinine↗
PubMedDate not supplied

Enhancement of radiation response of prostatic carcinoma by lonidamine.

Potential application of lonidamine (LND) to enhance radiation toxicity in prostate cancer was investigated using human prostate cancer cell lines and a rat tumor model (Dunning MAT LyLu). LND alone was cytotoxic with 50% inhibition concentration (IC50) between 0.5 and 0.8 mM. Preincubation with LND increased clonogenic toxicity of radiation. The sensitizer enhancement ratio was 1.8 to 2.2, depending on the cell line tested and it was consistent with inhibition of repair from potentially lethal damage. LND had limited effect in vivo on the Dunning model, consistent with its in vitro effect on the same cell line. LND did not alter the primary growth of the tumor. Fractionated irradiation caused a 40% decrease in tumor growth. LND injection (50 mg/kg) before fractionation did not cause any further decrease in tumor growth. Radiation dose fractionation and the combination treatment significantly reduced tumor metastasis in lungs.

Animals↗
PubMedDate not supplied

Risk factors for coronary artery disease and levels of lipoprotein(a) and fat-soluble antioxidant vitamins in Asian Indians of USA.

High rates of coronary artery disease have been reported in the Asian Indians who have migrated to other countries. Although many coronary artery disease risk factors (diabetes, high serum cholesterol, lipoprotein[a], and smoking) have been suggested, studies of coronary artery disease risk factors in Asian Indians living in USA are only a few. We investigated coronary artery disease risk factors in 110 Asian Indian physicians living in USA by questionnaire and measurement of their serum lipids and fat-soluble antioxidant vitamins. Differences in risk factors between genders, vegetarian diets and diabetic status were also studied. We found that lipoprotein(a) (mean=20 mg/dl), low density lipoprotein cholesterol, and diabetes (prevalence of 7.5%) are more important risk factors for coronary artery disease, but not smoking, when compared to other Americans. Higher levels of low density lipoprotein cholesterol, retinol, alpha-tocopherol, cryptoxanthin and lycopene, and lower levels of high density lipoprotein cholesterol were found in the males than in females. Comparable levels of lipoprotein(a) were found for males and females. Vegetarians, compared to non-vegetarians, had similar levels of lipids and fat-soluble antioxidants. Lower levels of retinol, lutein/zeaxanthin and lycopene were found in the diabetics compared to non-diabetics. These findings suggest that (1) the control of low density/high density lipoprotein cholesterol levels could be important in prevention of coronary artery disease in Indian males, (2) the vegetarian diets of Asian Indians do not favourably influence the serum lipid and antioxidant levels, and (3) increased serum levels of antioxidants may be beneficial for diabetics. Furthermore, for the first time, we show that serum levels of lutein/zeaxanthin and lycopene are significantly lower in the diabetics.

Adult↗