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Biomedical subjects

M Candito

Publications and source records attributed to M Candito.

At least 19 recordsLinked to original sources

[Thrombophilic factors in divers with undeserved decompression sickness].

UNLABELLED: In divers with a vascular disease in decompression sickness, who have not committed any technical error, thrombophilic risk factors were sought. Six cases of confirmed divers, without diving technical error, were investigated. Thrombophilic screening included proteins C, S, antithrombin III, and factor VIII assays, and circulating antibodies, Factor V Leiden, and mutation G20210A mutation in Factor II gene research. Total plasma homocysteine (Hcy), an atherosclerosis factor, even when slightly increased, nutitional factors: folate and vitamins B12 and B6, the cofactors of its metabolism, and inversely correlated with Hcy values, were assayed, and subjects were genotyped for mutation C677T in the MTHFR gene. RESULTS: In five divers, Hcy values were moderately increased, and in all the six, folate and/or B12 values were decreased. Three of them showed a genotype TT (mutation C677T), two, the genotype CT, and the sixth, an heterozygous Factor V Leiden. In these divers, a predisposition for vascular diseases, was detected, which was partially curable.

Adult↗

[Homocysteinemia and thrombophilic factors in unexplained decompression sickness].

INTRODUCTION: Decompression sickness with cerebral ischemic lesions occurs even in divers who have not committed any technical error. This study sought to determine whether an acquired or inborn thrombophilic factor might be involved. METHODS: 44 divers with ischemic medullar lesions (36 men, 8 women, mean age 39.9+/-4.7 yr) were compared with 44 controls (34 men, 10 women, mean age 38.2+/-5.1 yr). Coagulation screening included proteins S, C, and thrombin III and Factor VIII assays and circulating antibodies, Factor V Leiden, and mutation G20210A in Factor II gene research. Total plasma homocysteine (Hcy), an atherosclerosis factor (assayed by FPIA), folate and vitamin B12, (by microbiology), the cofactors of its metabolism, were assayed, and subjects were genotyped for mutation C677T on the MTHFR gene. RESULTS: Coagulation screening--protein C, protein S, or antithrombin III deficit or mutation G20210A--was negative in all divers. 3/44 divers were heterozygous for Factor V Leiden, 1/44 had IgG antiphospholipid antibodies (9p.cent). While not found in controls, these percentages were not greater than those reported in the general population. 3/44 divers had elevated Factor VIII levels, but repeat assays on Day 2 were much lower. 11/44 divers had a moderate increase in Hcy value (20p.cent): in 7 divers, Hcy values were>15 micromol/L, and in 4 others>12, vs. 2.3p.cent of the controls; 2/11 had normal vitamin levels and 11 divers had folate or vitamin B12 deficiency or both, vs 2.3p.cent controls with a vitamin B12 deficit (percentage significantly different). 7/26 divers were homozygous for the C677T mutation, i.e. 27p.cent vs 12p.cent of 98 healthy controls (laboratory technicians). CONCLUSIONS: A high percentage of unexplained diving accident victims had moderate HHC, a folate or vitamin B12 deficiency or both, that are easy to detect, plus a genetic predisposition to HHC or to coagulation abnormality. Easy-to-perform homocysteine, vitamin B12, and folate assays might prove helpful for primary prevention of diving accidents.

Adult↗

Levocarnitine administration in multiple sclerosis patients with immunosuppressive therapy-induced fatigue.

Nutritional factors and comedications are among the postulated causes of fatigue, a highly prevalent symptom in the multiple sclerosis (MS) population, with serious impact on patients' quality of life. Deficiency of carnitine may play a role by reducing energy production through fatty acid oxidation and numerous MS therapies can induce fatigue syndrome. The aim of this prospective open-labelled study was to collect and study serum carnitine levels in MS patients with and without disease-modifying treatment-induced fatigue syndrome. We investigated whether restoration of the carnitine pool might improve treatment-induced fatigue in MS patients. In our study, there was no statistical difference in fatigue frequency between treated and untreated patients (P=0.5). Matched to age, gender and treatments, carnitine levels were lower for MS treated patients compared to untreated MS patients (P <0.05) or controls (P <0.001). Consecutive patients with low plasma carnitine levels who experienced fatigue were substituted. Treatment consisted of oral levocarnitine, 3-6 g daily. All patients achieved normal plasma carnitine levels. For 63% of patients treated with immunosuppressive or immunomodulatory therapies, oral levocarnitine adjunction decreased fatigue intensity, especially in patients treated with cyclophosphamide and interferon beta.

Acetylcarnitine↗

[Clinical relevance of homocysteine monitoring in the diabetic patient].

Accelerated atherosclerosis is common in diabetes mellitus, although its extent is not always related to its strong association with classical cardiovascular risk factors. Diabetic patients, especially with type 2 diabetes, are prone to cardiovascular disease which is the leading cause of death in this population. Recent clinical studies among general population have shown that an even mild increase of homocysteinemia play an important role in the progression of atherosclerosis, either in coronary or peripheral arteries. An increasing amount of in vitro data is providing evidence that excess of homocysteine has a toxic effect on the arterial wall. This aminoacid thus appears to be not only a risk marker but also an emerging cardiovascular risk factor. The measurement of plasma homocysteine contributes to the identification, among the diabetic population, of patients at high cardio-vascular risk, with the aim of improving their global management. Moreover the addition of group B vitamins provides an easy and low-cost treatment to lower hyperhomocysteinemia.

Diabetes Complications↗

[Acute polyradiculoneuritis and dysautonomia: contribution of assaying catecholamines and their methoxylated metabolites].

Guillain-Barré syndrome is an acute demyelinating polyradiculoneuritis usually evolving with rapid, functional recovery. In severely paralysed patients, cranial nerve palsy and autonomic nervous system dysfunctions are common. Lesions of the spinal roots predominate but segmentary demyelination of peripheral nervous system reflects various clinical subtypes. Twelve patients (42,8 p. cent) had clinical dysautonomia. Ten had an increase of urinary methoxylated metabolites. Patients exempt of dysautonomia had normal biological parameters. The elevated level of urinary methoxylated metabolites is statistically correlated to clinical dysautonomia and can be used as a biological marker to monitoring demyelinating polyradiculoneuritis.

Autonomic Nervous System Diseases↗

Effects of strength exercise and training on the natural killer cell counts in elderly humans.

BACKGROUND: To investigate the effects of strength exercise and training on the natural killer cell counts in elderly humans. METHODS: The study examined strength exercise-induced changes in the number of NK cells and changes in stress hormones in 16 sedentary elderly subjects before and after a 8-week strength training intervention. Blood samples were obtained before, immediately and 6 hours after a standardized strength test. Blood samples were also obtained from ten sedentary young subjects, under the same conditions and from ten resting elderly subjects serving as time controls. RESULTS: Prior to training, older adults immediately decreased (from 165.4+/-19.5 microL to 110.6+/-14.3 microL; mean+/-SEM) their NK cell count in response to the standardized strength test, whereas young controls increased their count (from 157.6+/-28.8 microL(-1) to 241.4+/-39.8 microL(-1)). After strength training, the same old subjects slightly increased (from 159+/-19.8 microL(-1) to 166.6+/-19.7 microL(-1)) their NK cell counts in response to the standardized strength test. In elderly subjects, no increase in stress hormone was observed following the strength test either before or after the strength training programme. CONCLUSIONS: The results suggest that in sedentary older adults, unlike young subjects, strength exercises can induce a transient decrease in NK cell count which can be cancelled by a short-term strength conditioning. Therefore, caution should be taken regarding immunocompetence of older adults when initiating a rehabilitation programme based on strength.

Adult↗

Plasma total homocysteine and other thiols analyzed by capillary electrophoresis/laser-induced fluorescence detection: comparison with two other methods.

We present a new analytical method for thiol quantification in plasma, based on the use of capillary electrophoresis (CE) and laser-induced fluorescence (LIF) to analyze 6-iodoacetamidofluorescein derivatives. Quantitative results of homocysteine, glutathione, cysteinylglycine, and cystationine are presented. A comparison of the quantitation of homocysteine in plasma, using high performance liquid chromatography/fluorescence detection and fluorescence polarization immunoassay is proposed. The results indicate that these techniques for plasma total homocysteine (tHcy) determination can be used interchangeably. The major advantage of CE-LIF is that it can quantitate the thiols in one run while keeping the price of consumables reasonable.

Chromatography, High Pressure Liquid↗

Structure of the SLC7A7 gene and mutational analysis of patients affected by lysinuric protein intolerance.

Lysinuric protein intolerance (LPI) is a rare autosomal recessive defect of cationic amino acid transport caused by mutations in the SLC7A7 gene. We report the genomic structure of the gene and the results of the mutational analysis in Italian, Tunisian, and Japanese patients. The SLC7A7 gene consists of 10 exons; sequences of all of the exon-intron boundaries are reported here. All of the mutant alleles were characterized and eight novel mutations were detected, including two missense mutations, 242A-->C (M1L) and 1399C-->A (S386R); a nonsense mutation 967G-->A (W242X); two splice mutations IVS3 +1G-->A and IVS6 +1G-->T; a single-base insertion, 786insT; and two 4-bp deletions, 455delCTCT and 1425delTTCT. In addition, a previously reported mutation, 1625insATCA, was found in one patient. It is noteworthy that 242A-->C causes the change of Met1 to Leu, a rare mutational event previously found in a few inherited conditions. We failed to establish a genotype/phenotype correlation. In fact, both intrafamilial and interfamilial phenotypic variability were observed in homozygotes for the same mutation. The DNA-based tests are now easily accessible for molecular diagnosis, genetic counseling, and prenatal diagnosis of LPI.

Amino Acid Metabolism, Inborn Errors↗

Effects of a short-term strength training programme on lymphocyte subsets at rest in elderly humans.

The effects of a short-term strength training programme on resting lymphocyte subsets and stress hormone concentrations were analysed in 32 elderly sedentary subjects. Out of these 32 subjects, 8 women and 8 men [mean age 70.1 (SEM 1.0) years] were randomly assigned to a 8-week strength training programme which consisted of three sets of eight repetitions at 80% of one repetition maximum, for leg press, bilateral leg extension and seated chest press, 3 days a week. The remaining 8 women and 8 men [mean age 70.5 (SEM 0.9) years] served as controls. Absolute counts of lymphocyte subsets (CD20+, CD3+, CD3+CD4+, CD3+CD8+, CD3-CD56+CD16+) were measured with a new technique combining fluorescent microspheres and flow cytometry. In the trained subjects, substantial increases in strength took place in one repetition maximum during the 8-week training period for leg press [from means of 20.7 (SEM 1.0) to 23.6 (SEM 1.0) N x kg(-1) LBM (lean body mass)], chest press [from means of 5.4 (SEM 0.3) to 6.2 (SEM 0.3) N x kg(-1) LBM] and bilateral leg extension [from means of 6.3 (SEM 0.2) to 7.4 (SEM 0.3) N x kg(-1) LBM] movements. Baseline cortisol concentration (P < 0.01), CD20+ cell count (P < 0.05), CD3+ cell count (P < 0.05), and CD4+ cell count (P < 0.01) decreased in both groups secondary to circannual variations between winter and summer. No significant effect of strength training on resting adrenaline, noradrenaline and cortisol concentrations or distributions of lymphocyte subsets at rest was observed. The main finding of this study was to demonstrate that 8-week is too short a duration for a strength training programme to modify counts of lymphocyte subsets at rest in elderly sedentary adults.

Aged↗

Fasting, postprandial, and post-methionine-load homocysteinaemia and methylenetetrahydrofolate reductase polymorphism in vascular disease.

Hyperhomocysteinaemia is an independent risk factor for cardiovascular disease. The C677T mutation of the methylenetetrahydrofolate reductase (MTHFR) is a common genetic cause of increased homocysteine (HCY) levels. Post-methionine-load HCY concentrations allow identification of certain cases of hyperhomocysteinaemia not demonstrated by fasting levels. This study investigated the relationship between MTHFR polymorphism and (1) fasting HCY levels (77 patients); (2) post-methionine HCY levels (54 patients); and (3) postprandial HCY concentrations (36 patients) in cardiovascular disease. As expected, mean fasting HCY value was higher in the +/+ patients. Moreover, patients who were homozygous for the mutation exhibited significantly increased mean post-methionine-load HCY; in contrast, literature results are conflicting. Mean postprandial HCY, which is not known to be increased in controls, was also increased in the (+/+) patients, although the difference did not reach statistical significance, probably owing to the small size of the sample. MTFHR polymorphism is known to be aggravated by a drop in circulating folate. Additional risk factors may be more prevalent in patients with cardiovascular disease.

Adolescent↗

Whole blood serotonin content, tryptophan concentrations, and impulsivity in anorexia nervosa.

BACKGROUND: We hypothesized that anorectics with or without bulimic features would differ on impulsivity and indices of central serotoninergic function (high impulsivity being correlated with reduced serotoninergic function). METHODS: For all patients impulsivity rating scales and questionnaires detailing severity of eating disorder were assessed, and whole blood serotonin concentration (5-HT), free and total tryptophan (TT) concentrations, and large neutral amino acids (LNAA) were assayed. RESULTS: Nineteen patients with anorexia nervosa were included, 10 presented associated bulimic features and nine did not. Twelve healthy matched controls were also included. Our hypothesis was not verified. However, tryptophan concentration and the ratio of tryptophan concentration to LNAA allow us to separate controls from anorectics, whereas 5-HT concentration does not. Two significant and positive correlations were found: between impulsivity and anxiety in the total anorectic population, and between anxiety and serotonin in the impulsive group. CONCLUSIONS: All measured peripheral biologic indices except 5-HT concentration may be of interest in this pathology. Impulsivity and anxiety seem to be two personality components involved in anorexia nervosa. This study lead us to the necessity of redefining impulsivity in anorexia nervosa.

Adolescent↗

[Blood levels of homocysteine in patients under 55 years of age with acute coronary insufficiency].

OBJECTIVES: High blood levels of homocysteine have been recently described as a risk factor for thromboembolic events and early development of atherosclerosis. The aim of this work was to study homocysteine blood levels in patients under 55 years of age with acute coronary artery disease. PATIENTS AND METHODS: The study included 110 patients (98 men, 12 women) with poorly controlled angina pectoris (n = 35) or in the acute phase of myocardial infarction (n = 65). Homocysteine was assayed by liquid chromatography in all patients on the day of the acute episode and 24 hours later. Homocysteine levels were also determined in 40 controls under 55 years of age with no history of coronary artery disease. RESULTS: Blood level of homocysteine was 10.6 +/- 6.2 mumol/l in the patients and 7.7 +/- 2.5 mumol/l in the controls (p < 0.01). The difference was greater in the 30-40 year age rang with 14.4 +/- 2 mumol/l in patients versus 6.4 +/- 1.5 mumol/l in controls (p < 0.001). The assays were reproducible at 24 hours (difference less than 10%). The levels were significantly higher in patients with several diseased arteries than those with single-artery disease. The difference between patients and controls was especially remarkable for non-smokers and those with high cholesterol levels. CONCLUSION: Hyperhomocysteinemia would be a factor favoring early development of coronary atherosclerosis.

Acute Disease↗

[Cerebral vascular complication of hyperhomocysteinemia. Controlling thromboembolic complications with folates].

BACKGROUND: Young patients who experience cardiovascular events may have raised levels of homocysteine. There may be several causes for this hyperhomocysteinemia. CASE REPORT: Cerebrovascular disease occurred in a 40-year-old female smoker with hyperhomocysteinemia. This patient subsequently had several episodes of thromboembolism involving the brain and lower limb arteries. Prothrombin concentration was difficult to control with antivitamin K anticoagulants. Investigations to identify a genetic cause of hyperhomocysteinemia revealed that she was homozygous for the C677T mutation on the methylenetetrahydrofolate reductase gene. There was no G1691A mutation of the factor V gene, a risk factor for familial thrombosis. Supplementation with folic acid successfully halted episodes of thromboembolism (follow-up 2 years) and prothrombin levels stabilized under treatment. DISCUSSION: The C677T mutation, which is common in the general population (15.7%), cannot explain the effect of folate supplementation alone. Other mutations affecting homocysteine metabolism could have a potentializing effect on vascular events.

Adult↗

Total plasma homocysteine determination by liquid chromatography before and after methionine loading. Results in cerebrovascular disease.

Elevated homocysteine (HCY) levels in tissues and blood are associated with premature occlusive diseases. A number of techniques have been developed to assay HCY, including high-performance liquid chromatography (HPLC) with fluorimetric or electrochemical detection, and radioenzymatic methods. The present study evaluated the adaptation of a liquid chromatographic, ion-exchange technique with postcolumn derivatization using ninhydrin. Fasting and moreover post-methionine load total plasma HCY were assayed in 50 patients three months after a stroke and in 20 age-matched controls. Ion-exchange liquid chromatography was performed on an amino acid analyzer using a modified procedure to improve methionine and HCY separation. HCY values in the fasting state were moderately but significantly increased (P<0.05) in the patients compared to the controls: 10.5+/-3.4 versus 9.3+/-2.3 micromol/l. The difference between the two groups was amplified in post-load HCY results, which were significantly increased (P<0.05) in the patients: 41.6+/-17.8 versus 29.2+/-5.5 micromol/l in controls. The relationship between cerebrovascular disease and impaired HCY metabolism has previously been emphasized by other investigators. Our findings suggest that certain inherited and/or acquired HCY disorders observed in the fasting state (14%) and especially in post-methionine load conditions (32%) may occur during acute disease, and that total plasma HCY can be determined by ion-exchange chromatography even after oral methionine loading.

Adult↗

Urinary excretion of methylated catecholamine metabolites in a child with neuroblastoma maturing into ganglioneuroma.

Neuroblastomas are malignant tumors derived embryonically from the neural crest. Biological diagnosis relies on assay of urinary excretion of homovanillic acid (HVA), vanillylmandelic acid (VMA), and dopamine (DA). Spontaneous regression of these neoplasms has been reported by numerous investigators. The authors report the case of a child with neuroblastoma that illustrates the relationship between catecholamine metabolites and tumor maturation. At 1 month of age, this infant presented an adrenal neuroblastoma with multiple metastases (stage IV); the initial histological diagnosis based on examination of cutaneous metastases was neuroblastoma. At the age of 6 months, after chemotherapy, the primary tumor was resected; hepatic metastases were discovered at laparotomy. The histological diagnosis for all lesions was highly differentiated, mature ganglioneuroma-like tissue. The main biochemical abnormality at the time of diagnosis was an elevation in normetanephrine (NMN). HVA was only slightly increased but rose progressively during chemotherapy; it dropped back to normal levels after the sixth course. This case illustrates the potential benefits of separate assays of urinary methylated catecholamine metabolites for biochemical diagnosis and therapeutic management of neuroblastoma in addition to assays of HVA, VMA, and DA. Case findings suggest existence of a transformation process with maturation of the tumor involving enzymatic regulation and expression of MAO.

Adrenal Gland Neoplasms↗

Homocysteine response to methionine challenge in four obligate heterozygotes for homocystinuria and relationship with cystathionine beta-synthase mutations.

Fasting and post-methionine load plasma total homocysteine concentrations were investigated in the parents of two homocystinuric patients. Three genetic mutations in the cystathionine beta-synthase gene were found. In the patient of family 1, a frequent Caucasian mutation. T833C, was found on one allele, while the mutation on the other allele has not yet been defined. In the patient of family 2, a mutation C569T, recently described by Sperandeo and colleagues, was found on one allele, while a novel mutation, G346A, was characterized on the other allele. The frequent gene mutation T833C was detected in a heterozygous mother who, surprisingly, exhibited strictly normal fasting and post-methionine load homocysteinaemia. In contrast, in the other family, we found a novel mutation (G346A) in the mother located near Lys 119, the putative binding site of phosphopyridoxal phosphate. This mother exhibited increased fasting and post-methionine load homocysteinaemia. These observations could explain the conflicting results reported for vascular pathologies in parents of homocystinuric patients and direct the search for genetic mutations in these vascular pathologies.

Adolescent↗

Increased urinary catecholamines in a hypertensive child with renal artery stenosis.

We report a hypertensive child with renal artery stenosis who exhibited increased urinary excretion of norepinephrine (NE) and normetanephrine (NMN), while vanillylmandelic acid (VMA) excretion was within the normal range. The NMN values prompted us to investigate the patient for pheochromocytoma; for this purpose, NE was determined by plasma catecholamine assays in venous samples obtained by catheterization. The moderately increased NE levels could not be localized to any particular sampling site. Arteriography demonstrated right renal artery abnormalities. Following right nephrectomy with preservation of the right adrenal gland, arterial blood pressure returned to normal. The cause of increased NMN excretion without a concomitant rise in VMA during hypertension is discussed.

Angiography↗