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Biomedical subjects

G Calabrese

Publications and source records attributed to G Calabrese.

At least 109 records · Page 6Linked to original sources
PubMed1993

Detection of minimal residual disease by polymerase chain reaction in patients with different hematologic diseases treated by bone marrow transplantation.

Thirteen male patients affected by different hematologic diseases who underwent bone marrow transplantation (BMT) with female donors were investigated by cytogenetic analysis and polymerase chain reaction (PCR) amplification of a DNA sequence specific for the Y chromosome. In six of these patients, PCR showed the presence of the Y chromosome-related sequence; in only three of these did cytogenetic analysis confirm the presence of mixed chimerism. In the remaining three patients, the results of the PCR were confirmed by in situ hybridization on cell nuclei with a probe for the alpha-satellite of the Y chromosome. We compare results obtained with the two methods and discuss the meaning of the minimal residual disease detected by PCR in patients submitted to BMT.

Adolescent↗
PubMed1993

Caudate nucleus abnormalities in obsessive-compulsive disorder: measurements of MRI signal intensity.

A previous magnetic resonance imaging (MRI) study from our group reported increased size of the right caudate nucleus in obsessive-compulsive patients compared with control subjects. To test the hypothesis of a structural abnormality underlying such volume alteration, MRI signal intensity (SI), as an index of T1 relaxation values, was measured in the caudate nucleus of the same sampling data. Results showed higher SI values in the left caudate nucleus compared with the right in the patient group, whereas no asymmetry was found in the control group.

Adult↗
PubMed1993

New reinfusate composition in high UF haemodiafiltration: electrolyte solution combined with bicarbonate.

When high-permeability membranes are employed, high UF should be used in order to obtain optimal uraemic toxin removal and to avoid backfiltration. A high UF requires the infusion of an electrolyte solution including Ca2+ and Mg2+ which cannot be associated with bicarbonate in prepackaged solutions because of the risk of precipitation; therefore acetate or lactate are used as buffers. This study evaluated whether bicarbonate can be infused together with an electrolyte solution in high UF HDF, and if so, the clinical advantages that could be obtained by substituting acetate with bicarbonate in the reinfusate. In 12 patients on postdilutional high UF (121 +/- 10 ml/min) HDF (Qb 400, Qd 500 ml/min, dialysate containing Na, 141 +/- 2; K, 2.5; Ca, 3.5; Mg, 0.7; Cl, 111 +/- 2; acetate, 3; bicarbonate, 34 mEq/l; TMP 400 mmHg), an acid bag (Na, 128; K, 4; Ca, 7; Mg, 2; Cl, 141; acetate, 8 mEq/l), and a basic bag (Na, 150; HCO3, 80; Cl, 70 mEq/l), each containing 2 litres, were simultaneously infused through a Y connection. The final composition of reinfusate at the drip-chamber, combined with the above dialysate, allowed a negative intradialytic mass balance for Na, K, Mg and a positive one for Ca, acetate, to maintain prepostdialytic plasma values of these ions as well as bicarbonate close to normal limits. Furthermore, in five high-risk patients, clinical data were evaluated on high UF HDF, infusing a solution containing either acetate or bicarbonate, and an improvement of vascular stability was observed with the bicarbonate reinfusate.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetates↗
PubMed1993

H-Gly-His psi (NHCO)Lys-OH, partially modified retro-inverso analogue of the growth factor glycyl-L-histidyl-L-lysine with enhanced enzymatic stability.

A partially retro-inverso analogue of the natural growth factor GHK was synthesized, in which the -CONH- bond between histidine and lysine was modified as -NHCO-. This modification is not expected to perturb the spatial distribution of the side-chains, and therefore the binding processes, compared to the native peptide. In the synthesis of the analogue two possible systems for deblocking of N pi-Bom group of histidine have been applied and compared. An alternative method is also described for the incorporation of malonyllysine into the peptide chain. When evaluated with respect to resistance toward degradation by human plasma in vitro, the new peptide analogue showed approximately a ten-fold increase in stability versus the parent peptide.

Amino Acid Sequence↗
PubMed1992

Complex translocation involving Ph chromosome in a patient with typical chronic myelogenous leukemia.

We report a cytogenetic study of a patient with chronic myelogenous leukemia (CML) who, while displaying a Philadelphia (Ph) chromosome, resulting from a standard t(9;22) at diagnosis, during the chronic phase (CP) showed disappearance of the Ph and occurrence of new chromosome changes, including a marker probably arising from a translocation involving chromosome 17 and the Ph. In situ hybridization confirmed the cytogenetic appearance and demonstrated that the breakpoint on the Ph marker occurred below the BCR-ABL fusion gene.

Chromosome Deletion↗
PubMed1992

Leukemic evolution in three patients with myelodysplastic syndrome and unusual chromosome changes.

The authors describe three patients with myelodysplastic syndrome without a history of exposure to chemical agents and who showed many chromosome rearrangements not previously reported in this hematologic disorder, and a rapid outcome of the disease. The authors discuss the significance of the chromosome changes, suggesting, in agreement with others, that patients with complex rearrangements have a poor prognosis.

Acute Disease↗
PubMed1992

31Phosphorus magnetic resonance spectroscopy of the temporal lobes in schizophrenia.

Eleven schizophrenic patients and nine normal controls were studied using in vivo 31Phosphorous magnetic resonance spectroscopy (31P MRS) to test the hypothesis of metabolic asymmetry in the temporal lobes in schizophrenia. The controls did not demonstrate any asymmetry of phosphorous metabolite ratios, percentage of phosphorous metabolites, or pH. In the schizophrenics, however, phosphocreatine/beta-adenosine triphosphate (PCr/beta-ATP) and phosphocreatine/inorganic phosphate (PCr/Pi) effects appeared to primarily reflect higher ratios on the right side, while the percentage of beta-ATP appeared to primarily reflect higher relative concentrations in the left temporal lobe. Moreover, significant negative correlations were noted between total Brief Psychiatric Rating Scale scores and PCr/beta-ATP in both the right and left temporal lobes. These results support the hypothesis of an asymmetric distribution of 31P metabolites in the temporal lobe of schizophrenic patients, and also show an association between temporal lobe phosphorous metabolism and the severity of psychiatric symptomatology.

Adenosine Triphosphate↗
PubMed1992

Proton magnetic resonance spectroscopy of human brain: applications to normal white matter, chronic infarction, and MRI white matter signal hyperintensities.

A modified ISIS method, for image-selected localized proton magnetic resonance spectroscopy (1H MRS), was used to determine the ratios and T2 relaxation times of proton metabolites in normal subjects and in patients with chronic infarction and MRI white matter signal hyperintensities (WMSH). First, in patients with cerebral infarctions, increased concentrations of lactate were found in the majority of patients, and N-acetyl aspartate (NAA) was reduced to a significantly greater extent than choline (Cho) or creatine (Cre). For TE = 270 ms, the raw ratios of Cho/NAA, Cre/NAA, and Lac/NAA were significantly (P less than 0.05) increased from 0.23 +/- 0.02 (mean +/- SE), 0.20 +/- 0.01, and 0.05 +/- 0.01, respectively in the normal group to 0.39 +/- 0.08, 0.37 +/- 0.05, and 0.48 +/- 0.15 in the stroke group. Also, the T2 relaxation time of creatine was significantly (P = 0.007) increased from 136 ms in normal white matter to 171 ms in cerebral infarcts. Second, in patients with WMSH, no significant change of the proton metabolite concentrations could be detected with the exception of the choline which was significantly (P = 0.003) altered. The Cho/NAA ratio, after T2 and excitation profile correction, increased from 0.47 +/- 0.02 in the normal group to 0.64 +/- 0.05 in the WMSH group. Third, in normal white matter, the concentration of N-acetyl aspartate, choline, and lactate was estimated to 11.5, 2.0, and 0.6 mM, respectively, by assuming a total creatine concentration of 10 mM.

Aged↗
PubMed1992

Change in glucose metabolism after long-term treatment with deflazacort and betamethasone.

We have compared the long-term effects of different corticosteroids on glucose metabolism by carrying out a 75 g oral glucose tolerance test in 27 subjects before and after the administration of deflazacort or betamethasone for two months in random balanced sequence. Fasting plasma glucose and insulin concentrations were significantly higher after betamethasone, whereas deflazacort increased only fasting plasma insulin. After oral glucose there were significant increases in blood glucose and insulin after betamethasone compared with deflazacort. These results suggest that the degree of glucose intolerance and insulin resistance depends on the steroid used and on the dose given, although long-term treatment with deflazacort has a smaller effect on glucose metabolism than betamethasone.

Administration, Oral↗
PubMed1992

Cytogenetic survey of 80 patients with acute nonlymphocytic leukemia.

The authors report a cytogenetic survey of 80 patients with acute nonlymphocytic leukemia. The prognostic value of chromosome aberrations has been evaluated with three methods. The first one showed that patients with NN or AN bone marrow cellularity have a significantly better prognosis than those with AA cellularity; the second method confirmed the relatively good prognosis for patients with t(8;21) and abnormal 16 and a poor one for those with rearrangements of chromosomes 5 and/or 7. The authors also noted, surprisingly, that patients with hyperdiploidy had a significantly poorer prognosis than those with hypodiploidy and especially pseudodiploidy. The third method showed that patients with very complex karyotypes and a worse outcome than those with simple changes. Finally, they discuss the prognostic value of unusual and/or undeciphered chromosome changes detected in 18 patients, with a mean survival of 9.6 months, showing that these changes have a negative prognostic significance.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Effect of photic stimulation on human visual cortex lactate and phosphates using 1H and 31P magnetic resonance spectroscopy.

Previous animal and human studies showed that photic stimulation (PS) increased cerebral blood flow and glucose uptake much more than oxygen consumption, suggesting selective activation of anaerobic glycolysis. In the present studies, image-guided 1H and 31P magnetic resonance spectroscopy (MRS) was used to monitor the changes in lactate and high-energy phosphate concentrations produced by PS of visual cortex in six normal volunteers. PS initially produced a significant rise (to 250% of control, p less than 0.01) in visual cortex lactate during the first 6.4 min of PS, followed by a significant decline (p = 0.01) as PS continued. The PCr/Pi ratios decreased significantly from control values during the first 12.8 min of PS (p less than 0.05), and the pH was slightly increased. The positive P100 deflection of the visual evoked potential recorded between 100 and 172 ms after the strobe was significantly decreased from control at 12.8 min of PS (p less than 0.05). The finding that PS caused decreased PCr/Pi is consistent with the view that increased brain activity stimulated ATPase, causing a rise in ADP that shifted the creatine kinase reaction in the direction of ATP synthesis. The rise in lactate together with an increase in pH suggest that intracellular alkalosis, caused by the shift of creatine kinase, selectively stimulated glycolysis.

Adenosine Diphosphate↗
PubMed1992

Alterations in brain phosphorus metabolite concentrations associated with areas of high signal intensity in white matter at MR imaging.

Areas of high signal intensity in white matter are identified on brain magnetic resonance (MR) imaging studies in 25%-50% of elderly subjects. The authors used phosphorus-31 MR spectroscopy to characterize the metabolic status of hemispheric white matter brain volumes in 30 elderly subjects with white matter areas of high signal intensity at MR imaging. Compared with white matter volumes with no or minimal areas of high intensity, white matter volumes with extensive areas of high intensity evidenced a 26% decrease in the adenosine triphosphate (ATP)/inorganic phosphate (Pi) ratio (P = .03) and a 21% decrease in the ATP concentration (P = .05), with the Pi level unchanged. A pilot P-31 spectroscopic imaging study in a subject with a large, coalescing white matter area of high signal intensity demonstrated large reductions in metabolite concentrations in the high-signal-intensity area. These results suggest that extensive white matter areas of high signal intensity indicate a process that affects white matter cellular energy metabolism.

Adenosine Triphosphate↗
PubMed1992

Use of premixed insulin among the elderly. Reduction of errors in patient preparation of mixtures.

OBJECTIVE: To evaluate the accuracy of elderly patients in their mixing of regular and intermediate insulins, to assess the safety and efficacy of premixed insulins compared with extemporarily mixed insulins, and to determine patients' preferences. RESEARCH DESIGN AND METHODS: We conducted a crossover multicenter study of 5 mo duration. Premixed insulins and patient-mixed, human biosynthetic (rDNA) insulins were used among 64 insulin-treated patients with NIDDM. After a 4-wk run-in period, eligible patients were randomly assigned to treatment 1 (extemporarily mixed insulins) or treatment 2 (premixed insulins) for 8 wk. After that period, the two treatments were crossed for an additional 8-wk period. A blood glucose profile was recorded monthly and HbA1c was measured at the beginning and at the end of each treatment period. An in vitro skills test was performed to assess the accuracy and reproducibility of the patient preparation of insulin doses, and a questionnaire was used to determine their personal preferences for premixed versus extemporarily mixed insulin. RESULTS: In our study, the quality of the metabolic control was the same whether patients used self-mixed or premixed insulin. The differences in blood glucose profiles and HbA1c were negligible between type and periods of treatment. The overall number of hypoglycemic episodes increased during the trial in both groups, but the difference between treatments was not significant. The in vitro skills test, however, indicated that the accuracy in the preparation of insulin doses was significantly higher when patients aspirated from one vial compared with preparation from two vials (P < 0.001). The CVs were 3.7% when drawing up a single dose and 5.0% when preparing a mixture, but the ranges were rather elevated (0.1-20.7 and 0.6-35.8%, respectively). Forty-two patients described the preparation of their daily insulin dose as very easy and 21 described it as easy when using premixed insulins versus 11 and 43, respectively, when using extemporarily mixed insulins (P < 0.001). CONCLUSIONS: While the quality of the metabolic control was the same whether patients used self-mixed or premixed insulin, the in vitro skills test indicated that insulin preparation by elderly patients is highly inaccurate. In some patients, a modification of the contents of the insulin is likely to occur in a few days. The use of premixed insulins should lessen the errors that occur in mixing insulins and from the contamination of the second insulin vial. Draw-up errors could partially account for the lack of improvement of glucose control during the period when patients received premixed insulins. A longer observation period probably is needed to assess appreciable changes in the quality of diabetes control.

Aged↗