Search PubMed⌕ Search

Biomedical subjects

C Leonard

Publications and source records attributed to C Leonard.

At least 55 records · Page 3Linked to original sources
PubMed1995

Are axillary recurrence and overall survival affected by axillary extranodal tumor extension in breast cancer? Implications for radiation therapy.

PURPOSE: To determine the overall survival and local recurrence significance of axillary lymph node extranodal tumor extension (ETE) and whether axillary/chest-wall irradiation influenced any of these outcomes. MATERIALS AND METHODS: The records of 81 breast cancer patients treated with radical or modified radical mastectomy at a single surgical practice were eligible for study. Thirty-four patients had ETE: 17 with focal ETE (< 10 x high-power field) and 17 with extensive ETE (> 10 x high-power field). RESULTS: With a median follow-up duration of 92 months, only two patients had an axillary recurrence (2%): one had focal ETE and one had no ETE. Neither of these patients received axillary radiation therapy. Overall survival and recurrence-free survival were significantly decreased with ETE in patients whether axillary radiation therapy had been administered or not. Analysis showed that the age of the patient correlated significantly with extensive ETE (P = .04) and that the number of positive lymph nodes (< or = three v > three) correlated significantly with ETE (whether focal or extensive) (P = .0001). A multivariate analysis of extranodal tumor extension and number of positive lymph nodes showed that ETE was associated with decreased survival (P = .05), although to a lesser degree than number of positive lymph nodes (P = .003). CONCLUSION: These results show that ETE is associated with decreased survival and increased recurrence rates regardless of the extent of the radiation therapy field. Also, ETE does not necessarily indicate a significantly increased incidence of axillary recurrence. Therefore, axillary irradiation based on this pathologic finding may not be indicated.

Age Factors↗
PubMed1995

Molecular mapping of 21 features associated with partial monosomy 21: involvement of the APP-SOD1 region.

We compared the phenotypes, karyotypes, and molecular data for six cases of partial monosomy 21. Regions of chromosome 21, the deletion of which corresponds to particular features of monosomy 21, were thereby defined. Five such regions were identified for 21 features. Ten of the features could be assigned to the region flanked by genes APP and SOD1: six facial features, transverse palmar crease, arthrogryposis-like symptoms, hypertonia, and contribution to mental retardation. This region, covering the interface of bands 21q21-21q22.1, is 4.7-6.4 Mb long and contains the gene encoding the glutamate receptor subunit GluR5 (GRIK1).

Adolescent↗
PubMed1995

Abnormal chromatin clumping in granulocytes in a case of Ph1-negative, BCR-ABL rearrangement positive, haematologically atypical chronic myeloid leukaemia (CML).

In the present study, we report the case of a patient displaying an abnormal chromatin clumping (ACC) syndrome, a rare disease which shares features with both myeloproliferative and myelodysplastic disorders. Although various non specific cytogenetic abnormalities have been observed in ACC, the presence of a Ph1 chromosome has not been reported. In our patient, despite a lack of Ph1, PCR analysis of blood and bone marrow samples revealed a BCR-ABL rearrangement. These results indicate that at least some cases of ACC syndrome could represent a form of Ph1-negative chronic myeloid leukaemia.

Aged↗
PubMed1994

Submicroscopic deletions of 17p13.3 in type 1 Lissencephaly.

DNA markers YNZ22.1 and YNH37.3 were studied by Southern blotting in 14 patients with typical (11 cases) and atypical (3 cases) type 1 Lissencephaly, all with normal high resolution karyotype. A submicroscopic deletion was found in 2 typical cases: one with Miller-Dieker Syndrome (MDS), the other with Isolated Lissencephaly Sequence (ILS). These results suggest a genetic continuum between MDS and ILS. The low frequency of such deletions, especially in ILS, will necessitate direct testing of the newly identified LIS 1 gene.

Cerebral Cortex↗
PubMed1993

Use of ultrasound to guide radiation boost planning following lumpectomy for carcinoma of the breast.

PURPOSE: To determine if sonographic localization of the breast lumpectomy site is feasible and useful in boost planning. METHODS AND MATERIALS: The operative beds following lumpectomy were localized by ultrasound in 22 patients (15-infiltrating ductal, 7-ductal carcinoma in situ; size: .4-2.0 cm). Twelve patients had two ultrasound examinations on different days for a total of 34 examinations. Twenty-one patients had their course of boost electron therapy planned using ultrasound to guide field placement. While the patient was in the treatment position, the surgical scar was placed at the machine's isocenter. With the electron cone in place, the ultrasound transducer was placed within the cone on top of the surgical scar. The biopsy site was localized and the light field maneuvered so that it's central axis would follow the axis of the transducer, transecting both the scar and biopsy site. RESULTS: The operative bed was highly visible in 26 ultrasound examinations, visible in 7, and subtly visible in 1. Every biopsy site showed some hypoechoic area but most appeared as the mixed hypoechoic pattern. Ultrasound appearances were mixed or mostly hypoechoic (28), anechoic with irregular walls (4), and echoic (hypoechoic compared to parenchyma) (2). In two cases the surgeon placed surgical clips in the operative bed, and in both cases several of these clips could be identified at the margins of the operative bed as hyperechoic foci with shadowing. The mean depth of the operative bed was 21 mm (range 17-36 mm). In 12 patients, two ultrasound examinations were performed on different days, and the mean depth difference between these scans was 2 mm with a range of 0-5 mm. Among patients with two scans we found that both the location and appearance of the operative bed was highly reproducible. CONCLUSION: Ultrasound can successfully be used to localize the biopsy site and facilitate boost field placement in patients treated with lumpectomy and radiation.

Biopsy↗
PubMed1993

An estimate of the prevalence of enzootic abortion of ewes in Scotland.

The prevalence of enzootic abortion of ewes in Scotland was estimated over a period of five years. Between 1987 and 1991, 30.7 per cent of all flocks with breeding ewes in Scotland submitted ovine abortion material, and of these flocks 28 per cent showed evidence of the infection, giving a prevalence of 8.6 per cent. Regional differences were observed in both the submission rate and the prevalence.

Abortion, Veterinary↗
PubMed1990

Biclonal chromosome evolution of chronic myelomonocytic leukemia in a child.

A monosomy 7 was first detected in a 6-month-old boy with a chronic myelomonocytic leukemia. After etoposide treatment, relapse occurred after 29 months, with transformation of the disease into an acute myeloblastic leukemia. After bone marrow transplantations, two abnormal clones were found in marrow cells: 45,XY,-7,del(12)(p11p12)(66%), and 45,XY,-7,t(3;12)(q26;p12)(33%). Several karyotypic studies performed until the terminal phase exhibited the persistence of these two clones in the same proportion, although both independently acquired additional and often similar anomalies. The clone with t(3;12) acquired der(7),der(11),der(17),der(8),der(10),-5,-20, and the clone with del(12p), del(5q),der(4),der(8),der(10),der(17),-5,-20. The anomalies in 12p12 appear to represent an important although secondary event of the neoplastic process. The other anomalies may correspond to either those of a secondary acute nonlymphocytic leukemia, since they occurred after treatment by etoposide and alkylating agents, or to the natural evolution of myelomonocytic leukemia.

Bone Marrow↗
PubMed1990

Brain and plasma quinolinic acid in profound insulin-induced hypoglycemia.

Profound insulin-induced hypoglycemia is associated with early-onset neuronal damage that resembles excitotoxic lesions and is attenuated in severity by antagonists of N-methyl-D-aspartate receptors. Hypoglycemia increases L-tryptophan concentrations in brain and could increase the concentration of the L-tryptophan metabolite quinolinic acid (QUIN), an agonist of N-methyl-D-aspartate receptors and an excitotoxin in brain. Therefore, we investigated the effects of 40 min of profound hypoglycemia (isoelectric EEG) and 1-2 h of normoglycemic recovery on the concentrations of QUIN in brain tissue, brain extracellular fluid, and plasma in male Wistar rats. Plasma QUIN increased 6.5-fold by the time of isoelectricity (2 h after insulin administration). Regional brain QUIN concentrations increased two- to threefold during hypoglycemia and increased a further two- to threefold during recovery. However, no change in extracellular fluid QUIN concentrations in hippocampus occurred during hypoglycemia or recovery as measured using in vivo microdialysis. Therefore, the increases in brain tissue QUIN concentrations may reflect elevations of QUIN in the intracellular space or be secondary to the increases in QUIN in the vascular compartment in brain per se. L-Tryptophan concentrations increased more than twofold during recovery only. Serotonin decreased greater than 50% throughout the brain during hypoglycemia, while 5-hydroxyindoleacetic acid concentrations increased more than twofold during hypoglycemia and recovery. In striatum, dopamine was decreased 75% during hypoglycemia but returned to control values during recovery, while striatal 3,4-dihydroxyphenylacetic acid and homovanillic acid were increased more than twofold during both hypoglycemia and recovery.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Slot blot method for the quantification of DNA sequences and mapping of chromosome rearrangements: application to chromosome 21.

As an alternative to the methods of gene dosage based on either RFLP studies or Southern blots using specific and reference probes, we designed a "slot blot" method for the evaluation of the copy number of unique chromosome 21 sequences. Varying amounts of denatured DNA from a normal control, a trisomy 21 patient, and the subject to be analyzed were loaded on the same membrane. Successive hybridizations with reference probes and chromosome 21 probes were then carried out. Intensities of the signals on autoradiograms were quantified by densitometric scanning. Graphic and statistical analysis of the linear regressions between reference and chromosome 21 probe signals were performed, and the conclusion that the DNA from the studied subject had two or three copies for a given chromosome 21 sequence was assessed by statistical comparison of the slopes. As a test for the validation of this method, 10 coded blood DNAs from five normal controls and from five trisomy 21 patients were analyzed, by using two reference (COL1A1 and COL1A2) and two chromosome 21 (D21S11 and D21S17) probes. Among the 10 DNAs analyzed, it was possible to diagnose, with 100% accuracy, normal controls and trisomic 21 individuals. Application of this methodology to the mapping of partial chromosome 21 rearrangements is presented.

Base Sequence↗
PubMed1989

Genetic aspects of artificial insemination with donor semen: the French CECOS Federation guidelines.

The genetic problems raised by assisted reproduction using donor gametes (AID) are numerous and often complex. They concern the legitimacy and the appropriate forms of genetic screening for both gamete donors and recipients; the identification of genetic indications justifying the use of this method of reproduction; and ascertainment of the state of health of the conceptus at birth. The experience and guidelines of the French CECOS Federation, which comprises 20 AID treatment centers, are described. The discussion emphasizes the need for an international exchange of view on this subject.

Eugenics↗
PubMed1988

Retrograde changes in transglutaminase activity after peripheral nerve injuries.

It has been previously demonstrated that transglutaminase activity in rat superior cervical ganglion is rapidly and transiently increased minutes after nerve injury. The present series of experiments sought to determine: (1) whether or not similar changes are expressed by other peripheral neuronal systems, and (2) if injury-induced changes in the enzyme activity can be detected along the injured nerve, and if so do they occur in axons or in non-neuronal cells. In the nodose ganglion transglutaminase activity increased (approximately 40%) 48 h after the vagus nerve was crushed 25 mm from the ganglion. In the vagus nerve the activity was transiently increased (approximately 100%) within 1 h, followed by a second increase (approximately 140%) after 3 h. This occurred only in the proximal nerve stump close to the injury site and not in the section of nerve closer to the ganglion. Comparable enzyme activity was found in unoperated vagus nerve and in distal stumps of previously ligated vagus nerves. In dorsal root ganglia no changes were found for up to 24 h after the sciatic nerve was crushed 40 mm from the ganglion. In the facial nucleus a transient increase was observed after the facial nerve was crushed about 14 mm distally with a peak (approximately 300) at 3 days and a decline within 14 days. A second lesion of the facial nerve made 12 days following a conditioning lesion led to a rebound of enzyme activity in the facial nucleus.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Eleven new cases of del(9p) and features from 80 cases.

We report 11 cases of del(9p) and review 69 previously published ones. Of the 80 cases, 39 have a del(9p) as the sole anomaly. The symptoms are typical and diagnosis should be suspected at birth. The sex ratio does not appear to be unbalanced. A cardiac murmur is often present but surgery is rarely necessary. Mean IQ is 48. The number of reported cases with an associated trisomy has previously been underestimated. Death in infancy, owing mainly to gross visceral malformations, occurs more often in cases of del(9p) with another unbalanced chromosome segment (16/41) than in cases of del(9p) as the sole anomaly (1/39).

Abnormalities, Multiple↗
PubMed1987

Proposal for a scoring of the quality of the banding of chromosomes.

We propose an objective scoring of the quality of the banding of mitoses based on the number of bands (B), the length (L), and the width (W) of chromosome 7 in metaphase as used in the formula [LnB square root L/W]2. When no figure shows the quality of mitoses from which a breakpoint is described, this scoring could give information about it. It could be applied in cytogenetic cancer studies as well as for preparations with high resolution banding.

Bone Marrow Cells↗
PubMed1987

Characterization of the blast cell population in two neonates with Down's syndrome and transient myeloproliferative disorder.

The phenotype and in vitro growth properties of blood and marrow blast cells detected in two neonates with Down's syndrome and a transient leukaemic picture are presented. In both patients, blast cells at diagnosis were heterogeneous and expressed predominantly megakaryocyte and erythroid markers identified by membrane fluorescence using monoclonal antibodies or ultrastructural detection of platelet peroxidase and ferritin. An additional trisomy involving chromosome 22 was detected in blast cells from one patient. Blood and marrow cells colony-assays performed at diagnosis revealed precursors with an abnormal differentiation capacity similar to those found in acute myelogenous leukaemia colony assays. However, an unusual feature was the persistence of high numbers of precursor cells (namely erythroid) following a normal differentiation pathway. Phenotypically and cytogenetically abnormal cells spontaneously disappeared by week 4-6, but overt relapse occurred in one patient 20 months later. These results bring strong arguments in favour of the neoplastic nature of the transient leukaemic picture observed in some neonates with Down's syndrome. Furthermore, we suggest that this disorder can be individualized as a separate entity with specific phenotypic and biological properties.

Bone Marrow↗
PubMed1986

Multiple intestinal atresia and amyoplasia congenita in four unrelated infants: a new association.

Four unrelated infants with multiple segments of nonduodenal intestinal atresia and amyoplasia congenita are described. The extreme rarity of each of these conditions as a single entity indicates that their concurrent incidence in four separate unrelated patients is of significance with respect to pathogenesis. The nature of the relationship between the two conditions is unknown.

Arthrogryposis↗