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Biomedical subjects

S McKenzie

Publications and source records attributed to S McKenzie.

At least 109 records · Page 6Linked to original sources

An holistic approach to recovery from an overuse injury in a games player.

The management of a chronic injury to an international squash player is described. By good physiotherapeutic management and the involvement of an interdisciplinary team it was possible to make gains in the non-playing period. The rehabilitation period included physiological assessment on the basis of which a training programme was devised with target goals set throughout the period. Mental rehearsal of skills was included at all stages. As a result, the player's confidence was maintained and fitness levels improved. The long term prognosis has been good. The model could be applied to any sports injury.

Athletic Injuries↗

Lymphoblastic lymphoma in adults.

Fifty-one patients with lymphoblastic lymphoma (LBL) treated with one of five successive intensive chemotherapy protocols for acute lymphoblastic leukemia (ALL) since 1971 were reviewed. The patients were divided into leukemic and nonleukemic groups, and their clinical and laboratory parameters compared. The projected 5-year survival rate for all patients treated with the L10/17 protocols was 45% for both leukemic and nonleukemic LBL. The response to treatment was compared with that of 111 patients with ALL and was nearly identical. Poor prognostic factors were age beyond 30, WBC greater than 50,000/microL, failure to achieve a complete response (CR), and a late CR during induction. Leukemia at presentation, T cell surface markers, and the presence of a mediastinal mass did not adversely affect survival. The use of intensive chemotherapy protocols has proven to be a significant advance in the treatment of LBL.

Adolescent↗

Hairy cell leukemia. Durability of response to splenectomy in 26 patients and treatment of relapse with androgens in six patients.

Twenty-three of 26 patients with hairy cell leukemia evaluable for response to splenectomy had significant improvement in anemia, thrombocytopenia, and/or neutropenia. Eight of the 23 had a recurrence of cytopenia after a median response duration of 4 to 5 months (range, 1-22). The remaining 15 patients did not have a recurrence of cytopenia at 20 months median follow-up (range, 1-76). Six patients with postsplenectomy cytopenia were given androgenic steroids. Two of the six had an improvement in anemia and thrombocytopenia, and a third patient had an improvement in neutropenia. It was concluded that, although most patients with hairy cell leukemia have initial improvement in cytopenia with splenectomy, a significant number of them either fail to respond or have recurrent cytopenia after initial response to splenectomy. A trial of androgenic steroids is a reasonable therapeutic option in these patients. Alternative therapies are reviewed and recommendations made.

Adult↗

The effect of smoking on perception of muscle tension.

It has been suggested that smoking may reduce affect in high-arousal situations by blocking peripheral physiological cues. The effects of smoking on perception of one type of physiological response, muscle activity, was evaluated in two studies. In study 1 male and female smokers were exposed to four conditions: high and low arousal crossed with smoking or deprivation. Results showed that smokers produce less muscle activity during high- than low-arousal situations, and that smoking reduced sensitivity to muscle activity in females, but enhanced it in males. These perception differences were not related to arousal as assessed by heart rate, which was elevated in all high-arousal situations. When compared to nonsmokers, smokers in a deprived state generate more muscle activity during the perception task, but showed no differences in sensitivity. These results represent the initial demonstration that smoking can alter the perception of physiological processes. Study 2 was designed to determine whether the effects of smoking were specific to muscle tension or indicative of a more generalized perceptual change. Perception of muscle tension and decibel levels were compared in smoking or deprived female smokers who were in the high-arousal situation. Results for muscle-tension perception in high-arousal situations were similar to those in study 1, but smoking did not alter perception of auditory stimuli.

Adolescent↗

Analysis of T-cell differentiation antigens in acute lymphatic leukemia using monoclonal antibodies.

Leukemic cells in 134 patients with ALL were analyzed by a panel of mouse monoclonal antibodies. Two antibodies are reactive with all peripheral blood T cells but define different surface antigens (Leu-1 and Leu-4). Two other antibodies react with antigens that are restricted to suppressor/cytotoxic T cells (Leu-2) and to helper T cells (Leu-3). We also used antibodies to the receptor for sheep red blood cells (SRBC) (Leu-5) and to a human "TL-like" antigen that is found on most thymocytes but not in peripheral T cells (Leu-6). An antibody to the human p29.34 "Ia-like" molecule was also tested. Of the 134 ALL patients, 17 had a predominance of SRBC-rosetting (Leu-5+) lymphoblasts ("T" ALL), expressing different surface phenotypes defined by this panel of monoclonal antibodies. These phenotypes were not readily classifiable according to a scheme of sequential stages of normal differentiation proposed. Moreover, the lymphoblasts in 8 of 113 patients not expressing conventional B- to T-cell markers ("null" ALL) reacted with the monoclonal anti-T-cell antibodies. This study suggests that the classification of lymphoblasts in ALL based on the reactivities observed with this panel of mouse monoclonal antibodies is not easily reconciled with current models of normal T-cell differentiation. However, it should be emphasized that the precise sequence of antigenic expression by cells undergoing thymic differentiation is still not fully known, and further phenotypic analysis of ALL cells might contribute to an improved understanding of this malignancy.

Adolescent↗

Treatment of acute nonlymphocytic leukemia in adults: response to 2,2-anhydro-1-B-D-arabinofuranosyl-5-fluorocytosine and thioguanine on the L-12 protocol.

Fifty-one adult patients with acute nonlymphocytic leukemia (excluding acute promyelocytic leukemia) were treated on the L-12 protocol. The L-12 differed from the preceding L-6 in that 2,2-anhydro-1-B-D-arabinofuranosyl-5-fluorocytosine (AAFC), replaced arabinosylcytosine (ara-C) together with 6-thioguanine (TG) for remission induction. Achievement of remission was followed by an extended 14-week multi-drug consolidation program. With this more intense regimen, an overall complete remission rate of 49% and a median remission duration of 23.7 months were achieved; these results were not significantly better than the 57% complete remission rate and 8.6 months median remission duration obtained with the L-6 regimen. Four year disease-free survival was 22% on the L-12 compared with 16% on the L-6 protocol. No relationship between prognosis and FAB classification was found on either the L-6 or the L-12 protocol.

Adolescent↗

The acute monocytic leukemias: multidisciplinary studies in 45 patients.

The clinical and laboratory features of 37 patients with variants of acute monocytic leukemia are described. Three of these 37 patients who had extensive extramedullary leukemic tissue infiltration are examples of true histiocytic "lymphomas." Three additional patients with undifferentiated leukemias, one patient with refractory anemia with excess of blasts, one patient with chronic myelomonocytic leukemia, one patient with B-lymphocyte diffuse "histiocytic" lymphoma and one patient with "null" cell, terminal deoxynucleotidyl transferase-positive lymphoblastic lymphoma had bone marrow cells with monocytic features. Another patient had dual populations of lymphoid and monocytoid leukemic cells. The true monocytic leukemias, acute monocytic leukemia (AMOL) and acute myelomonocytic leukemia (AMMOL), are closely related to acute myelocytic leukemia (AML) morphologically and by their response to chemotherapy. like AML, the leukemic cells from the AMMOL and AMOL patients form leukemic clusters in semisolid media. Cytochemical staining of leukemic cells for nonspecific esterases, presence of Fc receptor on the cell surface, phagocytic ability, low TdT activity, presence of surface "ruffles" and "ridges" on scanning EM, elevations of serum lysozyme, and clinical manifestations of leukemic tissue infiltration are features which accompanied monocytic differentiation in these cases.

Adolescent↗

Heterogeneity of cell lineages in L3 leukemias.

Five cases of adult leukemia with L3 morphology in bone marrow were studied for the presence of immunologic, metabolic, and enzymatic markers. Among the five patients, there were four males and female. Median age was 66 with a range of 16-80 yr. Median survival was only 5 mo. Serum lactate dehydrogenase (LDH) levels, 3H-thymidine labeling indices, and DNA/RNA content of the L3 lymphoblasts were markedly elevated. B-cell markers were found in three cases, two exhibiting surface membrane IgM-lambda, and one IgG-K. Terminal deoxynucleotidyl transferase (TdT) enzymatic activity was consistently low in this group. In one case, the L3 lymphoblasts displayed only surface Fc receptors demonstrated by the binding of aggregated IgG. TdT activity was found to be significantly increased. In another instance, the lymphoblasts formed spontaneous rosettes with sheep erythrocytes and exhibited paranuclear staining with acid phosphatase. TdT activity was found to be low. Although most of the L3 leukemias are neoplasias of B lymphocytes, other lineages may also express this morphology.

Adult↗

Morphological classification, response to therapy, and survival in 263 adult patients with acute nonlymphoblastic leukemia.

Bone marrow smears of 263 protocol patients with acute nonlymphoblastic leukemia (ANLL) and related disorders treated between 1970 and 1978 at MSKCC were reviewed blindly by two pairs of hematomorphologists and classified according to the FAB system. It was found necessary to add one category (MO) for acute undifferentiated leukemia and to define more precise quantitative criteria for the categories M1-M6 based on bone marrow differential counts. Using this modified FAB classification, agreement between the two observer groups based on morphology alone was 69%. Cytochemical stains were essential in establishing the diagnosis in 9%, led to a change of diagnosis by one observer team in 14%, and helped to confirm the diagnosis in 32% of cases. Complete remission rates, remission duration, and survival were not significantly different among diagnostic categories. Myelodysplastic syndromes (MDS: M6, RAEB, CMML; CR rate 48%) and ANLL without differentiation (M0, M1, M5a; CR rate 50%) appeared to do less well than ANLL with partial differentiation (M2, M3, M4, M5b; CR rate 59%) on all three protocols studied. Auer rods were present in 53% of all cases with 63% in the myeloid categories (M1-M4). Auer rods were found to be the single most important prognostic parameter in this study, with a complete remission (CR) rate of 68% in the Auer-rod-positive and of 40% in the Auer-rod-negative group (p < 0.0001). Survival was significantly longer for patients exhibiting Auer rods (p < 0.0002). Median survival for the total group was 13.5 mo and median remission duration for responders was 11.5 mo in the Auer-rod-positive group compared to 6.2 mo median survival and 9.2 mo median remission duration for the Auer-rod-negative group.

Acute Disease↗

A clinical comparison of beclomethasone dipropionate delivered by pressurised aerosol and as a powder from a rotahaler.

14 children with severe asthma were studied for 2 months in a double-blind cross-over trial to compare the efficacy of beclomethasone dipropionate delivered as an aerosol and as a powder from a rotahaler. Inhalation via the aerosol was satisfactory in 13 patients, each of whom used the rotahaler correctly. Younger children preferred to use the rotahaler. Comparison of daily symptoms, twice daily peak expiratory flow rate (PEFR), and use of salbutamol during the 2 months of the trial showed that control of asthma was equally good, irrespective of the device used to deliver active beclomethasone.

Adolescent↗

The coexistence of acute myeloblastic leukemia and diffuse histiocytic lymphoma in the same patient as demonstrated by multiparameter analysis.

Measurement of cellular DNA content by flow cytometry demonstrated presence of two distinct aneuploid neoplasms in a patient who developed acute myeloblastic leukemia (AML) 4 mo after diagnosis of a diffuse histiocytic lymphoma (DHL). A lymph node aspirate contained peroxidase-negative, "null," hyperdiploid (2.6C) DHL cells, while the bone marrow (BM) contained 84% primitive peroxidase-positive tetraploid AML cells (4.0C). Minor populations of hyperdiploid HDL and normal diploid cells could be detected by flow-cytometry in the BM, and all three populations were also seen in the peripheral blood.

Adult↗

A comparison of oral choline theophyllinate and beclomethasone in severe perennial asthma in children.

Fourteen children with perennial asthma previously treated with beclomethasone dipropionate were studied for four months in a crossover trial to compare the efficacy of choline theophyllinate and beclomethasone dipropionate aerosol in the control of their symptoms. Assessments were made using twice daily peak flow measurements, together with daily records of symptom scores and use of extra salbutamol. Beclomethasone and oral choline theophyllinate together improved control of asthma in comparison with beclomethasone alone. Reduction of the dose of beclomethasone from 400 microgram/day caused worsening of asthma. Oral choline theophyllinate did not prevent this deterioration and therefore cannot replace beclomethasone for the long-term treatment of such asthmatic patients.

Administration, Oral↗

Serum theophylline levels in asthmatic children after oral administration of a slow-release aminophylline preparation (Phyllocontin Continus tablets).

Twenty-seven asthmatic children aged 3--14 years who were considered to need continuous treatment were studied. Fifteen received a low dose of slow-release aminophylline and fifteen a high dose. There was a wide range of serum theophylline levels between individuals for similar doses. Fourteen of twenty children who had five or more levels measured throughout the day had differences between maximum and minimum levels of greater than 4 microgram/ml. The peak levels occurred between 2 and 6 hours after the dose. Only four children had levels exceeding 20 microgram/ml and none was symptomatic. We suggest a dose of 14 mg/kg/dose twice daily which should be reviewed after peak serum theophylline levels are measured.

Adolescent↗

Prophylactic heparin therapy in acute promyelocytic leukemia.

Twenty-four patients with acute promyelocytic leukemia were reviewed. Group I, treated between July 1970 and September 1973, received arabinosylcytosine and 6-thioguanine, and there was one complete remission, with 4/7 dying during induction with intracerebral hemorrhages, and 2/7 dying within one month. Group II, treated between May 1974 and March 1975, received daunomycin and arabinosylcytosine without heparin and 2/8 went into remission, with 6/8 dying during induction, 5 with intracerebral hemorrhages. Group III, treated between March 1975 and November 1976, received the identical chemotherapy as group II but with the addition of prophylactic heparin and there were 7/9 complete remissions, with 2/9 dying with intracerebral hemorrhages. In Group III there was an increased incidence of remission induction when compared to Group II (p less than .05) or when compared to Groups I and II combined (p less than .05). There was also a decreased incidence of fatal hemorrhage in Group III. This suggests that prophylactic heparin is useful during remission induction in acute promyelocytic leukemia.

Adolescent↗