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Biomedical subjects

R M Slater

Publications and source records attributed to R M Slater.

69 records · Page 4Linked to original sources
PubMed1985

Phenotypic and karyotypic properties of hyperdiploid acute lymphoblastic leukaemia of childhood.

The DNA/cell content was measured by flow cytometry in samples obtained from 98 unselected children with acute lymphocytic leukaemia (ALL) at diagnosis. The frequency of anomalies in modal DNA content was compared to that encountered in acute childhood non-lymphocytic leukaemia (ANLL) and disseminated non-Hodgkin's lymphoma (NHL). In ALL the most frequent (35%) aberration in DNA content was an increase by 20% relative to the modal value of normal white blood cells. This subcategory, referred to as hyperdiploid ALL (HD-ALL), was characterized by a close association with the expression of the c-ALL surface marker (20/20 patients) and characteristic numerical chromosome changes, including tri- or tetrasomy of chromosome 21. Moreover, patients with hyperdiploid ALL had a much lower peripheral leucocyte count (P = 0.001) than those with diploid disease and a varying proportion of their leukaemic cells existed in the peripheral blood as morphologically normal lymphocytes expressing the c-ALL antigen. Within the standard risk category, patients with HD-ALL had a longer disease-free survival than those with diploid disease (P = 0.058). It is concluded that routine analysis by flow cytometry can conveniently and consistently detect ALL patients with hyperdiploid chromosome numbers. Hyperdiploid ALL constitutes a fairly large subtype of childhood ALL with specific biological and karyotypic properties, possibly associated with favourable prognosis.

Bone Marrow↗
PubMed1983

Chromosome studies on acute nonlymphocytic leukaemia in children.

Cytogenetic studies have been carried out on 17 children with acute nonlymphocytic leukaemia (ANLL). Of the 16 patients analysed at diagnosis, 11 had acquired clonal chromosome abnormalities. Four out of seven cases with acute myeloid leukaemia (M2) had 8;21 translocations, two of which were variants. Comparisons with other data on ANLL confirmed the association between the 8;21 translocation and the younger age groups. There are indications that the Netherlands may be a high incidence area for this translocation. Differences in the type of chromosome anomalies between childhood and adult ANLL were evident suggesting that different aetiologic factors may be involved.

Adolescent↗
PubMed1982

Cytogenetic studies on four cases of non-endemic Burkitt lymphoma.

Cytogenetic studies carried out on four children with non-endemic Burkitt lymphoma showed: 1) Two with the typical translocation t(8;14)(q24;q23); 2) one with a variant t(2;8)(p11;q24); and 3) one with apparently normal chromosomes 8 and 14. Additional chromosomal variation was present in all four patients. Two were shown to have a duplication of part of the long arm of chromosome 1 (1q23 leads to 1q32 and 1q23 leads to 1q42). Epstein Barr virus studies on two patients showed that one was positive and the other negative. A comparison of these results with other non-endemic cases in the literature has been made revealing a wider range of chromosomal variation than has been hitherto reported for endemic cases. The finding that chromosome 8 is also involved in the variant translocations in Burkitt lymphoma suggests that its changes may contribute more to the tumour development than the than the 14q+.

Bone Marrow↗
PubMed1982

Chromosome number 11 and Wilms' tumor.

Cytogenetic studies have been carried out on cells derived from two Wilms' tumors in vitro. Both tumors had a diploid chromosome range. One tumor was shown to have a definite stemline; 46,XY,4p+,del(9)(q22),11p-q,11p+, and the other range of variation chiefly involving chromosomes No. 11, 4, 7, and 2; most changes in chromosome No. 11 took the form of deletions of the short arm. High resolution chromosome analysis of peripheral blood lymphocytes of the two patients revealed apparently normal karyotypes. These findings suggest that changes in the short arm of chromosome No. 11 are important in the development of Wilms' tumor in normal individuals. This association is reinforced by the fact that patients with spontaneous aniridia with a 1 in 3 risk of Wilms' tumor have been reported as having a specific 11p13 deletion.

Blood Cells↗
PubMed1981

SOD-A and chromosome 21. Conflicting findings in a familial translocation (9p24;21q214).

A balanced maternal chromosome translocation (9p24;21q214) resulted in two offspring with unbalanced karyotypes. One of these, a girl trisomic for both segment 9pter to 9p24 and segment 21pter to 21q214, was found to have a SOD-A activity not significantly different from those found in a group of five cases with trisomy 21. However, clinical evaluation of this girl revealed no symptoms of the Down syndrome. These findings suggest that, providing the gene dosage theory is correct, the gene for SOD-A is probably localized on chromosome 21 proximal to, or in, band q21.

Child↗
PubMed1981

Transport of dieldrin between air and water.

The transfer rate of dieldrin from water to air has been measured in a wind tunnel yielding transfer velocities in the range 2.6 x 10(-5) to 1.5 x 10(-4) cm s-1. The transfer rate from air to water was measured with a wetted-wall column and gave transfer velocities in the range 9 x 10(-3) to 5 x 10(-2) cm s-1. An analysis of the data showed that processes in the liquid phase offered no larger resistance to the transfer of dieldrin between air and water than processes in the gas phase. The results are considered in relation to the transfer of dieldrin between the atmosphere and the ocean surface layer.

Air Movements↗
PubMed1981

Partial trisomy 3q due to a de novo translocation t(X;3) (p21;q12).

A patient with several cogenital malformations, principally in the face, cardiovascular system and genitalia, was found to have the karyotype 46,X,der(X),t,X;3)(Xqter leads to p21::3q12 leads to 3qter). A comparison of the clinical and cytogenetical findings with smaller cases in the literature led to the conclusion that a partial trisomy 3q is the most likely cause for the symptoms in this patient.

Abnormalities, Multiple↗
PubMedDate not supplied

Effects of alfentanil and lidocaine on the hemodynamic responses to laryngoscopy and tracheal intubation.

This study was undertaken to determine whether lidocaine and/or alfentanil can effectively abolish or attenuate the increase in mean arterial pressure (MAP), heart rate (HR), and rate pressure product (RPP) associated with rapid sequence induction of anesthesia. Sixty patients were randomly divided into four groups. Group 1 received saline 10 ml, group 2 received lidocaine 2 mg/kg, group 3 received alfentanil 15 micrograms/kg, and group 4 received alfentanil 30 micrograms/kg. All patients were induced with sodium thiopental 4 mg/kg and succinylcholine 1.5 mg/kg to facilitate tracheal intubation. The study drug was given after sodium thiopental was administered, and the investigator was blinded to it. Blood pressure (BP) and HR were recorded at the following times: before induction; after induction but before laryngoscopy and intubation; and 1, 3, and 5 minutes after intubation. Alfentanil 15 and 30 micrograms/kg given in rapid sequence fashion with thiopental and succinylcholine effectively blunted the hemodynamic responses to laryngoscopy and tracheal intubation. Lidocaine 2 mg/kg and saline were found to be ineffective in blunting these same responses.

Adult↗
PubMedDate not supplied

The effect of respiratory alkalosis on oxygen consumption in anesthetized patients.

STUDY OBJECTIVE: To investigate whether hyperventilation significantly altered oxygen consumption in anesthetized and paralyzed patients undergoing surgery. DESIGN: Open crossover trial with 1 hour of hyperventilation preceded and followed by 1 hour of normoventilation. SETTING: University medical center. PATIENTS: Eight patients (five men and three women) undergoing lengthy orthopedic surgery with general anesthesia and muscle paralysis. INTERVENTIONS: After baseline normoventilation for 1 hour (Period 1), the anesthetized patients were hyperventilated to an arterial carbon dioxide tension (PaCO2) of 20 to 25 mmHg for 1 hour (Period 2). Patients then experienced another hour of normoventilation (Period 3). MEASUREMENTS AND MAIN RESULTS: Hemodynamic variables, electrocardiography, temperature, end-tidal partial pressure of CO2 (PETCO2), oxygen consumption (VO2), carbon dioxide production, and minute ventilation were continuously followed throughout the study, and arterial blood gases were drawn at the beginning and end of each study period. During the period of hyperventilation, pH was significantly higher and P.ETCO2 and PaCO2 significantly lower compared with the periods of normoventilation. VO2 was significantly increased during hyperventilation compared with the periods of normoventilation. Hemodynamic variables and temperature were similar in the three study periods. CONCLUSIONS: In anesthetized paralyzed patients, there is an increase in whole-body VO2 with hypocapnic alkalosis.

Adult↗