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Biomedical subjects

A Carella

Publications and source records attributed to A Carella.

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

Metabolic changes in neuronal migration disorders: evaluation by combined MRI and proton MR spectroscopy.

PURPOSE: To assess the role of 1H-magnetic resonance spectroscopy (MRS) in detecting biochemical abnormalities in neuronal migration disorders (NMDs). METHODS: We performed 1H-MRS studies on 17 brain NMD areas [five polymicrogyria, eight subcortical heterotopia, and four cortical dysplasia on magnetic resonance imaging (MRI)]. The study group consisted of 15 patients, all but one affected by partial epileptic seizures. Spectra were acquired from volumes of interest localized on NMDs and contralateral sides and compared with those obtained on gray and white matter of 18 neurologic controls. RESULTS: NMD lesions were characterized by lower N-acetylaspartate to creatine (NAA/Cr) and choline to Cr (Cho/Cr) ratios than those of the white (p = 0.002 and p = 0.004) and gray matter (p = 0.03 and p = 0.06) of neurologic controls. In addition, the normal-appearing contralateral sides to the NMD lesions showed a significant decrease of Cho/Cr ratio when compared with those of white (p = 0.003) and gray matter (p = 0.05) of neurologic controls. No relation was found between NAA/Cr decrease, EEG abnormalities, and NMD sides, or between NAA/Cr ratios, duration of epilepsy, and frequency of seizures. Lactate signal was detected in the spectra of four patients who had an epileptic seizure a short time before MR examination. CONCLUSIONS: NAA/Cr decrease may be related more to structural and functional alteration of the NMD sides than to epileptic activity in these lesions. Low Cho/Cr may be related to a more extensive diffuse hypomyelination than suggested by the MRI findings. An activation of anerobic glycolysis during and after seizures could account for the presence of lactate. These data confirm that H-MRS is an advanced technique that may provide useful biochemical information in vivo on neurobiologic processes underlying NMDs.

Brain↗
PubMed1997

Autologous bone marrow transplantation for patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia following MDS. Chronic and Acute Leukemia Working Parties of the European Group for Blood and Marrow Transplantation.

Intensive chemotherapy followed by autologous bone marrow transplantation (ABMT) may provide an alternative therapy for young patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia following MDS (sAML) lacking a suitable donor. We report the results for 79 patients with MDS/sAML transplanted with autologous marrow in first complete remission (CR). Within the total group of 79, a cohort of 55 patients for whom the duration of first CR was known were compared with a matched control group of 110 patients with de novo AML. The 2-year survival, disease-free survival (DFS), and relapse rates for the 79 patients transplanted in first CR were 39%, 34%, and 64%, respectively. The relapse risk was greater than 55% for all stages and all disease categories. Patients younger than 40 years had a significantly (P = .04) better DFS (39%) than patients older than 40 years (25%). The DFS at 2 years was 28% for the cohort of 55 patients transplanted for MDS/sAML and 51% for those transplanted for de novo AML (P = .025). Relapse rates were 69% for patients with MDS/sAML and 40% for those with de novo AML (P = .007). ABMT for MDS or secondary leukemia results in a lower DFS when compared with similarly treated patients with de novo AML due to a higher relapse rate. The DFS of 28% for these patients suggests that autotransplantation may be a valuable therapy for this disease. The low treatment-related mortality rate of less than 10% supports the view that sufficient numbers of hematopoietic stem cells are present in patients with MDS to allow adequate repopulation after autologous stem-cell transplantation.

Acute Disease↗
PubMed1996

Autografting Ph-negative blood precursor cells in chronic myeloid leukaemia.

The study was devised to evaluate whether it was possible to collect Philadelphia-negative precursor cells in patients with chronic myeloid leukaemia. The approach was based on previous experience showing that complete remission (Ph-negative bone marrow cells) is rarely achieved after chemotherapy and is very short-lasting. We decided to explore whether it was possible to collect Ph-negative precursor cells in peripheral blood during the early phase of haemopoietic recovery. These data show that: the collection of Ph-negative precursor cells occurred in 12/16 (75%) patients mobilized within one year of diagnosis (group A) versus 12/33 (36%) in patients with a history of more than one year of disease (group B). Furthermore the numbers of Ph-negative precursor cells were significantly much higher at diagnosis. Ten patients mobilized at diagnosis were subsequently autografted with such Ph-negative precursor cells. Five of them remain Ph-negative from 4 to 12 months while the other five have percentages of Ph-positive cells in their marrow ranging from 20% to 70%. In this stage of the disease the procedure is safe and associated with a very good compliance. Occasional restoration of Ph-negative haemopoiesis could be observed up to 40 months after autograft, in patients of group B, but most of patients revert to Ph-positive haemopoiesis. in conclusion these data suggest that it is possible to restore Ph-negative haemopoiesis in 70% of patients mobilized at diagnosis. This percentage represent the highest one can obtain without allogeneic BMT, and this includes patients who never would have been cytogenetic responders to IFN-alpha. Whether and how long for Ph-negative status can be maintained is a matter for future observation and study.

Adult↗
PubMed1994

Autologous transplants for chronic myelogenous leukaemia: results from eight transplant groups.

Chronic myelogenous leukaemia (CML) can be cured by donor marrow transplant. Unfortunately, suitably HLA-matched related or unrelated donors are not available for the majority of patients. Transplant of stem cells derived from a patient's own marrow or peripheral blood (autologous transplant) avoids the need for an HLA-matched donor, is associated with a less complicated and shorter hospital course than donor transplantation, and has been successful in the treatment of other haematological malignancies. We report results of autologous transplants in 200 patients with CML at eight marrow transplant centres over seven years. This is the first multicentre analysis of autologous transplants for CML and reports on the largest number of patients studied to date. We show that autologous transplants provide a plateau in the survival curve not observed in conventional treatments. Autologous transplants are associated with a high engraftment rate, low mortality, and prompt return of both younger and older patients to normal activity levels. Our results suggest that autologous transplants provide an alternative to conventional treatment in the care of patients not eligible for donor transplant.

Adolescent↗
PubMed1994

Cerebral ischemia: magnetic resonance angiography and transcranial Doppler evaluation.

We examined 21 patients with ischemic cerebrovascular disease using magnetic resonance angiography and transcranial Doppler. In 17 patients (81%), the results obtained by the two methods were concordant. In our opinion, the associated use of transcranial Doppler and magnetic resonance angiography provides an accurate diagnostic evaluation of ischemic stroke patients, not only allowing the site of possible steno-occlusive disease of large and medium cerebral vessels to be identified, but also offering the possibility of obtaining dynamic information concerning the direction of blood flow in the presence of compensatory circulations at the level of Willis' circle.

Adult↗
PubMed1994

Biological characterization of stem cell present in mobilized peripheral blood of CML patients.

Peripheral blood stem cell grafts are now frequently used for autologous transplantation of patients with malignancies. In this report we address the question of whether true long-term repopulating pluripotent hematopoietic stem cells (PHSC) are mobilized into peripheral blood and whether stem cells isolated from CML patients are depleted of Philadelphia chromosome positive cells. The presence of stem cells in mobilized peripheral blood (MPB) was examined by staining the CD34+Lineage- (Lin-) population for the expression of the Thy-1 antigen. The extent and kinetics of mobilization of CD34+Thy-1+ Lin- cells into peripheral blood were studied. In our analysis the percentage of these cells was found to vary widely depending on the day of leukapheresis and the individual patient. Fluorescence activated cell sorting (FACS) was used to isolate Thy-1 subsets from MPB which were analyzed for activity in in vitro long term cultures and in two in vivo models in which SCID-hu mice were implanted with human fetal bone or thymus grafts. The long term culture assay shows that the cells which express Thy-1 are enriched for cobblestone area forming activity (CAFC), an assay which can be used as a measure of detecting PBSC's in vitro. This CD34+Thy-1+ Lin- cell population was capable of producing both B and myeloid cells, and maintaining CD34+Lin- cells in these long term cultures. Moreover, the CD34+Thy-1+Lin- cell subset possessed a higher ability to engraft and to produce multilineage hematopoietic lineages in the SCID-hu bone assay and T cells in the SCID-hu thymus assay.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, CD↗
PubMed1994

Enhanced MR in the acute phase of Wernicke encephalopathy.

MR in a patient with Wernicke encephalopathy showed enhancement in the mamillary bodies and inferior quadrigeminal plate. These findings pointed to the correct diagnosis, which can be difficult to make in patients who are not alcoholics.

Acute-Phase Reaction↗
PubMed1993

Neuro-Behçet: clinical features and MRI correlates.

This paper highlights the fundamental role of MRI in the diagnosis of Neuro-Behçet disease. We present 4 cases examined between 1990 and 1991. Treatment in all the cases seems to have improved the patients' prognoses.

Acenocoumarol↗
PubMed1993

Magnetic resonance angiography monitoring of streptokinase in occlusion of the middle cerebral artery.

A 77 year old woman was hospitalized one hour after the onset of right hemiplegia and aphasia. Magnetic resonance imaging (MRI) examination was negative and MRA indicated occlusion of the left middle cerebral artery. Treatment with streptokinase was instituted (a 60 minute intravenous infusion of 1.5 MU of streptokinase in 100 ml of saline solution). Two hours after infusion, the patient's motor function clearly improved. An MRA examination performed six hours later showed partial recanalization of the obstructed vessel. Our report demonstrates the potential usefulness of MRA monitoring during thrombolytic therapy.

Aged↗
PubMed1993

Autologous bone marrow transplantation for pediatric Hodgkin's disease: a case-matched comparison with adult patients by the European Bone Marrow Transplant Group Lymphoma Registry.

PURPOSE: We analyzed the outcome of autologous bone marrow transplantation (ABMT) in pediatric and adult patients with Hodgkin's disease (HD) by means of a case-controlled study. PATIENTS AND METHODS: Eighty-one pediatric HD patients who had undergone ABMT and who had been reported to the European Bone Marrow Transplant Group (EBMTG) Lymphoma Registry were compared with a case-matched group of 81 adult patients who had undergone the same procedure. The case-matching was performed following selection of the main prognostic factors for progression-free survival (PFS) by multivariate analysis. RESULTS: The PFS rate was not significantly different between the groups (39% for the pediatric group v 48% for the adult group). The overall relapse/progression rates for the groups were 52% and 40%, respectively. This was not a statistically significant difference and the sites of relapse were similar. There was no significant difference in the incidence or causes of procedure-related morbidity or mortality of the two groups. CONCLUSION: This study suggests that patients with pediatric HD have the same outcome at ABMT as their adult counterparts; however, long-term complications will need to be carefully monitored.

Adolescent↗
PubMed1991

Interactions of magnesium and chloride ions on tone and contractility of vascular muscle.

Replacement of extracellular chloride ions ([Cl-]o) by other anions, on contractility and the effects of extracellular magnesium ions ([Mg2+]o) on spontaneous mechanical activity, as well as on agonist-induced responses of rat aorta and portal vein, were studied. Replacement of [Cl-]o with acetate (Ac-) or isethionate (Ise-) ions resulted in an increase and decrease, respectively, of the spontaneous mechanical activity frequency in portal vein; the amplitudes of the spontaneous mechanical activity were attenuated by Ac- and Ise- substitution. Withdrawal of [Mg2+]o in Cl(-)-containing media resulted in elevation of tension development in rat aortas, whereas a similar maneuver in media with Ac- or Ise-, substituted for [Cl-]o, resulted in abrogation of this tension development. Use of disulfonic stilbene anion-channel blockers, DIDS (4,4'-diisothiocyano-2,2'-stilbene disulfonate, 400-600 microM) and SITS (4,4'-acetamido-4'-isothiocyano-2,2'-stilbene disulfonic acid, 400-600 microM), failed to influence either spontaneous mechanical activity or basal tone of rat portal portal vein or aortas. Incubation of DIDS or SITS in Mg(2+)-free media also failed to influence mechanical responses to withdrawal of [Mg2+]o. Use of the Cl- cation transport inhibitor bumetanide (30-80 microM) also failed to alter spontaneous mechanical activity or basal tone in either the presence or absence of [Mg2+]o. Ac- and Ise- substitution attenuated norepinephrine- and K(+)-induced contractile responses in portal vein and aorta, Caffeine-induced contractions of aortas were potentiated by withdrawal of [Mg2+]o in Cl(-)-containing media but inhibited in Ac(-)- or Ise(-)-substituted solutions. In the presence of [Mg2+]o, substitution of foreign anions resulted in alterations in the agonist contractile dose-response curves; EC50s were increased whereas maximum tensions were depressed. Withdrawal of [Mg2+]o amplified these effects. Substitution of Ac- or Ise- for [Cl-]o in the presence or absence of [Mg2+]o depressed contractions induced by Ca acetate in aortas and portal vein. These results suggest that: (1) Cl- plays an important role in regulating spontaneous mechanical activity, basal tone, and contractility in rat aorta and portal vein; and (2) Cl- probably physiologically mediates some of the effects and actions of [Mg2+]o on intracellular release of and influx of Ca2+ in these smooth muscles.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1991

Autologous bone marrow transplantation for acute myeloblastic leukemia in Europe: further evidence of the role of marrow purging by mafosfamide. European Co-operative Group for Bone Marrow Transplantation (EBMT).

Fifty-nine European teams have reported 919 autografts for the consolidation of acute myelocytic leukemia (AML) up to December 31, 1989. The distribution for autologous bone marrow transplantation (ABMT) was 671 in first complete remission (CR1) and 196 in CR2. Pretransplantation regimes were: total-body irradiation (TBI), 456; busulfan plus cyclophosphamide (BU-CY) 174; marrow purging with mafosfamide, 269 (corresponding to 26% of all patients in CR1 and 41% in CR2). Patients autografted in CR1 with no high risk factor (standard risk) had a leukemia-free survival (LFS) and relapse rate at 7 years of 48 +/- 2 and 41 +/- 3%, respectively. Of all the prognostic factors studied, only secondary leukemia was correlated with a poorer LFS (19 +/- 9% at 1 year) and a higher relapse rate (76 +/- 11%) (p less than 0.0001). For patients autografted in CR2, the LFS and relapse rate were 34 +/- 4 and 54 +/- 5%. With the restriction of a shorter follow-up, the results achieved with the BU-CY combinations (LFS and relapse rate at 3 years, CR1 47 +/- 6 and 45 +/- 7%; CR2, 37 +/- 9 and 50 +/- 10%) did not differ from those with TBI or other chemotherapy combinations. LFS and relapse rates were correlated with several pretransplant intervals: in CR1, patients reaching CR more rapidly (less than or equal to 40 days) had a better LFS (53 +/- 3 versus 42 +/- 3%; p = 0.03) and a lower relapse rate (46 +/- 3 versus 57 +/- 3%; p = 0.03). In patients autografted less than 3 months, 3-6 months and more than 6 months after CR, the LFS was 26 +/- 5, 49 +/- 3, and 55 +/- 4%, respectively, and the relapse rates 63 +/- 5, 38 +/- 3, and 36 +/- 4% (p less than 0.0001 for both). In CR2, patients autografted more than 18 months after the initial diagnosis had a better LFS (42 +/- 5 versus 24 +/- 5%; p less than 0.001) and a lower relapse rate (45 +/- 6 versus 65 +/- 6%; p less than 0.001). For those autografted less than 3 months, 3-6 months and more than 6 months after CR, the probability of LFS was 30 +/- 5, 30 +/- 7, and 50 +/- 9% (p = 0.06), respectively and the relapse rates 63 +/- 6, 50 +/- 8, and 36 +/- 8% (p = 0.01).(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1991

[Lymph nodes of the neck. Diagnosis using magnetic resonance with gradient-echo technique].

As for the pathologic conditions of neck lymph nodes, the clinician needs to know if the involved node is reactive, phlogistic, or neoplastic in nature. If accurate tumor staging is required, imaging techniques play a fundamental role. Our study was aimed at assessing the actual role of MR imaging in the evaluation of neck lymph node involvement. The study was performed using an MR Max Plus by General Electrics operating with an 0.5 T superconductive magnet. We employed gradient-echo (GE) pulse sequences with TR 500, TE 15 ms and 90 degrees flip angle for T1-weighted images, and with TR 500, TE 30 ms and 25-30 degrees flip angles for T2-weighted images; for Pd-T2-weighted images, TR was 520, TE 30 ms, and flip angles were 40-45 degrees. The results were correlated with histopathologic findings obtained at biopsy. The advantages of GE sequences were: 1) whole neck imaging--thus saving time, and reducing radiation dose and contrast media; 2) optimal anatomical and topographic evaluation of the lesion; 3) imaging of the longitudinal diameter of the node; 4) higher sensitivity for lymph node tissue modifications; 5) imaging of necrosis, hemorrhage, and/or fibrosis. GE sequences were especially useful for accurate tumor staging, in the follow-up, and to verify response to therapy. However, even though MR imaging has proven to have high sensitivity, its specificity was similar to that of contrast-enhanced CT. Further studies with the use of paramagnetic contrast media are needed to solve these problems.

Diagnosis, Differential↗