Search PubMed⌕ Search

Biomedical subjects

A Cascino

Publications and source records attributed to A Cascino.

At least 37 records · Page 2Linked to original sources
PubMed1999

Effect of cisplatin and paclitaxel on plasma free tryptophan levels. An in vitro study.

UNLABELLED: Emesis is a common side effect of some antineoplastic drugs. Cisplatin (CP) induces a biphasic pattern of emesis referred to as acute (AE) and delayed (DE) emesis. The serotonergic system plays a major role in the pathogenesis of CP-induced AE, as suggested by the therapeutic efficacy of 5HT3 receptor antagonists. The pathogenesis of CP-induced DE are not clear. To date, there are no pharmacological agents which satisfactorily control DE. We hypothesize that increased availability of tryptophan (TRP) for the synthesis of brain serotonin (5-HT) could, at least in part, contribute to CP-induced DE. In fact, within 2-4 hrs of administration, CP is largely bound to albumin (ALB) with consequent possible displacement of TRP which circulates in plasma mostly (90% of total plasma TRP) bound to its natural carrier, ALB. To test this hypothesis, we studied in vitro the effect of increasing doses of cisplatin on F-TRP in plasma obtained from healthy volunteers. We also tested the effects of therapeutic amounts of paclitaxel, an antineoplastc agent which does not cause emesis. RESULTS: F-TRP concentrations increased in a dose-dependent manner following incubation with cisplatin, in contrast to paclitaxel (PTX). CONCLUSIONS: The preliminary data obtained suggest that CP, but not PTX, at therapeutic doses, increases plasma F-TRP concentrations. This increase has likely negligible relevance in CP-induced AE, which is induced by the 5-HT released by the enterochromaffin cell system, while it might play a role in the pathogenesis of CP-induced DE. In fact, CP binding to ALB is stable for 4-5 days following administration, thus suggesting long-term TRP displacement from ALB and enhanced brain 5-HT synthesis and release. Whether increased TRP availability for 5-HT synthesis might be the pathogenic mechanism for CP-induced DE in vivo, is currently being tested.

Cisplatin↗
PubMed1999

Plasma amino acid concentrations in patients with acute myelogenous leukemia.

Changes in plasma-free amino acid (PFAA) concentrations in the presence of solid tumors have been widely described. Conversely, the PFAA profile in patients with acute leukemias is less well defined. The aim of the present study was to clarify whether the PFAA profile is altered in patients with acute myeloid leukemia (AML), whether the profile differs from the PFAA profile of solid tumors, and whether it may predict outcome of AML. Fasting PFAA were measured in 40 untreated, normally nourished patients with AML (17 males, 23 females), ages 22-78 y, with white blood cell (WBC) counts ranging from 1.08 to 276.5 x 10(3)/cm2, and in 24 healthy volunteers. Plasma concentrations (mu mol/L, mean +/- SE) of glutamic acid (GLU), free tryptophan (FTRP), ornithine (ORN), and glycine (GLY) were significantly higher in AML (GLU: 90.2 +/- 6.1 versus 37 +/- 8; FTRP: 7.0 +/- 0.6 versus 4.8 +/- 0.3, P < 0.005; ORN: 108.7 +/- 5.8 versus 78 +/- 6, P < 0.001; GLY: 295.0 +/- 14.8 versus 239 +/- 9, P < 0.01), whereas serine (SER), methionine (MET), and taurine (TAU) were significantly lower in AML than in controls (SER: 109.0 +/- 5.8 versus 130 +/- 4, P < 0.03; MET: 25.5 +/- 1.3 versus 33 +/- 3, P < 0.03; TAU: 46.5 +/- 3.5 versus 81 +/- 2, P < 0.001), and tended to be even lower in patients who had not responded to chemotherapy or had relapsed within 18 mo of enrollment. Such changes were unrelated to age, sex, and WBC count. Changes in PFAA that occur in AML are only in part similar to those observed in solid tumors. The reduction of TAU appears to be a typical feature of AML and might be secondary to the deficiency of its precursors SER and MET. Further studies are under way aimed at clarifying whether PFAA might predict prognosis in AML, whether PFAA is normalized by remission induction, and if its correction may be of any benefit for patients with hematologic malignancies.

Acute Disease↗
PubMed1999

Histological analysis and ancient DNA amplification of human bone remains found in caius iulius polybius house in pompeii.

Thirteen skeletons found in the Caius Iulius Polybius house, which has been the object of intensive study since its discovery in Pompeii 250 years ago, have provided an opportunity to study either bone diagenesis by histological investigation or ancient DNA by polymerase chain reaction analysis. DNA analysis was done by amplifying both X- and Y-chromosomes amelogenin loci and Y-specific alphoid repeat locus. The von Willebrand factor (vWF) microsatellite locus on chromosome 12 was also analyzed for personal identification in two individuals showing alleles with 10/11 and 12/12 TCTA repeats, respectively. Technical problems were the scarcity of DNA content from osteocytes, DNA molecule fragmentation, microbial contamination which change bone structure, contaminating human DNA which results from mishandling, and frequent presence of Taq DNA polymerase inhibiting molecules like polyphenols and heavy metals. The results suggest that the remains contain endogenous human DNA that can be amplified and analyzed. The amplifiability of DNA corresponds to the bone preservation and dynamics of the burial conditions subsequent to the 79 A.D. eruption.

Alleles↗
PubMed1998

Ancient DNA in human bone remains from Pompeii archaeological site.

aDNA extraction and amplification procedures have been optimized for Pompeian human bone remains whose diagenesis has been determined by histological analysis. Single copy genes amplification (X and Y amelogenin loci and Y specific alphoid repeat sequences) have been performed and compared with anthropometric data on sexing.

Amelogenin↗
PubMed1998

Effects of oral 5-hydroxy-tryptophan on energy intake and macronutrient selection in non-insulin dependent diabetic patients.

OBJECTIVE: In obese patients, brain serotonergic stimulation via orally administered 5-hydroxy-tryptophan (5-HTP), the precursor of serotonin, causes decreased carbohydrate intake and weight loss. Since diabetes mellitus is associated with depressed brain serotonin, hyperphagia and carbohydrate craving, we hypothesized that in diabetic patients, orally administered 5-HTP stimulates brain serotonergic activity and thus normalizes eating behaviour. To test this hypothesis, we investigated whether in diabetic patients: 1) predicted brain serotonin concentrations are depressed as a result of decreased availability of the precursor, tryptophan; and 2) oral 5-HTP is effective in reducing energy and carbohydrate intake. SUBJECTS AND METHODS: 25 overweight non-insulin dependent diabetic outpatients were enrolled in a double-blind, placebo-controlled study, and randomized to receive either 5-HTP (750 mg/d) or placebo for two consecutive weeks, during which no dietary restriction was prescribed. Energy intake and eating behaviour, as expressed by macronutrient selection, were evaluated using a daily diet diary. Plasma amino acid concentrations and body weight, as well as serum glucose, insulin and glycosylated haemoglobin were assessed. RESULTS: 20 patients (nine from the 5-HTP group and 11 from the Placebo group) completed the study. Brain tryptophan availability in diabetic patients was significantly reduced when compared to a group of healthy controls. Patients receiving 5-HTP significantly decreased their daily energy intake, by reducing carbohydrate and fat intake, and reduced their body weight. CONCLUSIONS: These data confirm the role of the serotonergic system in reducing energy intake, by predominantly inhibiting carbohydrate intake, and suggest that 5-HTP may be safely utilized to improve the compliance to dietary prescriptions in non-insulin dependent diabetes mellitus.

5-Hydroxytryptophan↗
PubMed1998

Antisense oligonucleotides and myotonin gene expression in C2 mouse cells.

By describing the behavior of myotonin mRNA levels, from the quiescent to the differentiated state in C2 mouse myoblasts, we produced evidence bearing on the role of myotonin gene product in the control of cell growth and differentiation. To study the role of myotonin in myotonic dystrophy (DM) pathogenesis, we developed a suitable cellular model where myotonin gene expression was modulated by phosphorothioate antisense oligonucleotides in C2 cultured cells. Furthermore, an isoform of the gene product, similar to that described in humans and not yet described in the mouse, was found.

Animals↗
PubMed1997

Plasma tryptophan levels and anorexia in liver cirrhosis.

OBJECTIVE: Increased brain tryptophan (TRP) availability for serotonin synthesis may play a role in the pathogenesis of anorexia. Since in chronic liver failure, increased plasma and cerebrospinal fluid TRP concentrations are characteristically reported, we hypothesize that also in liver cirrhosis increased brain TRP availability may constitute the pathogenic mechanism of anorexia. To test this hypothesis, the association between anorexia and plasma TRP was investigated. METHODS: Anorexia and plasma amino acid concentrations were evaluated in 16 patients with liver cirrhosis and compared with those obtained in 13 healthy volunteers. RESULTS: According to a questionnaire, 11 cirrhotic patients were considered as anorectic. In these patients, brain TRP availability was significantly higher than in nonanorectic patients and controls. DISCUSSION: Increased brain TRP availability is also associated with anorexia in liver cirrhosis, and supports the hypothesis that increased serotonergic activity may constitute the common pathogenic mechanism for anorexia associated with different diseases.

Adult↗
PubMed1997

[Energy metabolism in cancer patients].

The presence of cachexia as defined by a series of clinical symptoms, such as anorexia, weight loss, muscular atrophy, tissue wasting, altered organ function, is frequently observed in cancer and makes a decisive contribution to morbidity and mortality. The onset of neoplastic cachexia is characterized by two events: the presence of primary or secondary anorexia and alterations of the host's intermediate metabolism. Among the most frequent metabolic alterations described in cancer patients is an absolute or relative increase in basal energy consumption with lack of adaptation to fasting. The causes of increased energy consumption in cancer patients are still not clear. Numerous studies on glucose, fat and protein metabolism induced by cancer have significantly contributed to our understanding of the phenomenon. The main alterations of the glucose metabolism are increased glucose turnover and reduced peripheral utilization, both of which probably depend on the presence of the tumour, as shown by their normalization after treatment. Increased gluconeogenesis, from lactate and from gluconeogenetic AA, is the main factor responsible for increased glucose turnover. The main alterations of the fat metabolism are increased mobilization of lipids from adipose tissues, reduced use of exogenous triglycerides and increased oxidation of free fatty acids that cannot be suppressed by glucose. The main alterations of protein metabolism are increased protein turnover with reduced synthesis and increased degradation of muscular proteins and increased hepatic protein synthesis. Knowledge of the pathogenesis of neoplastic cachexia represents a valuable aid for its effective prevention and treatment.

English Abstract↗
PubMed1997

CTG repeat number in the nonaffected allele of myotonic dystrophy patients is not critical for disease expression.

To investigate whether unusual allele segregation might explain the dominant negative effect of the expanded allele for myotonic dystrophy on myotonin protein kinase mRNA metabolism, which is suggested to cause the disease, we determined the number of CTG repeats at the DM locus in the nonaffected alleles of 64 DM (dystrophia myotonia) patients. The relative distribution was then compared with the distributions obtained from alleles of the normal parents and normal siblings of DM patients. Comparison was also made with the allele distribution of normal subjects from the same geographic area. It appears that the CTG repeat number of the nonaffected allele in DM patients is not critical for the expression of the disease.

Alleles↗
PubMed1996

Myotonic dystrophy: antisense oligonucleotide inhibition of DMPK gene expression in vitro.

Antisense phosphorothioate oligonucleotides, targeted against the first codon starting region of DMPK mRNA, were successfully used in K562 and HepG2 cells to decrease DMPK expression. The most effective antisense oligo, MIO1, when added to K562 cells, shows a 75% reduction of the DMPK gene expression 6 hours after addition. The same molecule, when encapsulated in liposomes, delays myotonin mRNA decrease at 24 hours after cell treatment. This considerable success with such inhibition in vitro could be utilised to generate a cell model to study myotonic dystrophy (DM) chemio-physiological alterations.

Base Sequence↗
PubMed1996

Cancer anorexia: new pathogenic and therapeutic insights.

During tumor growth, anorexia and reduced food intake markedly contribute to the development of malnutrition, thus worsening overall patients' survival. A better understanding of the pathophysiology of eating behavior may lead to new and more effective therapies, aiming at counteracting the detrimental effects of anorexia and reduced food intake on nutritional status and survival in cancer patients. Brain tryptophan and serotonin concentrations seem to play a pivotal role in the regulation of eating behavior. Increased brain serotonin activity is indeed associated with a reduction of food intake. It has been recently hypothesized that increased availability of tryptophan to the brain and the consequent increased serotonin activity may represent the pathogenic mechanism for cancer-associated anorexia. According to this hypothesis, the modulation of brain serotonin activity may result in an improvement of anorexia. Reducing brain tryptophan availability represents a possible mechanism to restore brain serotonin activity to normal. There is evidence that the oral administration of neutral amino acids competing with tryptophan for brain entry results in a significant improvement of cancer anorexia. The same treatment may also be effective in improving secondary anorexia, which is associated with other chronic illnesses, including renal and liver failure, sepsis, and so forth, sharing a similar pathogenic mechanism.

Animals↗
PubMed1995

Bacteriophage T4 gene 28.

The complete nucleotide sequence of bacteriophage T4D gene 28 has been determined. Gene 28 product is a structural component of the viral baseplate for which an enzymatic activity has also been proposed.

Amino Acid Sequence↗
PubMed1992

Eating behavior and adherence to dietary prescriptions in obese adult subjects treated with 5-hydroxytryptophan.

Previous observations have shown that oral administration of 5-hydroxytryptophan (5-HTP) without dietary prescriptions causes anorexia, decreased food intake, and weight loss in obese subjects. To confirm these data over a longer period of observation and to verify whether adherence to dietary restriction could be improved by 5-HTP, 20 obese patients were randomly assigned to receive either 5-HTP (900 mg/d) or a placebo. The study was double-blinded and was for two consecutive 6-wk periods. No diet was prescribed during the first period, a 5040-kJ/d diet was recommended for the second. Significant weight loss was observed in 5-HTP-treated patients during both periods. A reduction in carbohydrate intake and a consistent presence of early satiety were also found. These findings together with the good tolerance observed suggest that 5-HTP may be safely used to treat obesity.

5-Hydroxytryptophan↗
PubMed1991

Two bacteriophage T4 base plate genes (25 and 26) and the DNA repair gene uvsY belong to spatially and temporally overlapping transcription units.

The bacteriophage T4 DNA recombination-repair gene uvsY located at or near an origin of DNA replication and adjacent to the late base plate genes 25 and 26. Our present results reveal a complex transcription pattern in the region encompassing these genes. Most significantly, uvsY and two ORFs, downstream of it, all of which are transcribed from a middle promoter before the onset of DNA replication, are also part of a larger late transcription unit which includes the base plate genes 25 and 26. The late genes 25 and 26 are transcribed not only late, but also early from one or several early promoters further upstream. Translation, however, is inhibited by secondary structures which sequester the ribosome binding site in the early transcript. We discuss possible advantages of these transcriptional patterns for T4 DNA recombination, replication, and repair. The predicted and in vivo-expressed 23.9-kDa product of gene 26 is smaller than the reported size of gene 26 protein isolated from base plates, suggesting that nascent gp26 might be processed to a larger protein during assembly.

Base Sequence↗