Low Density Lipoprotein Receptor Activity in Human Leukemic Cells—Relation to Chromosome Aberrations

ABSTRACT. Lindquist R, Vitols S, Gahrton G, Öst Å, Peterson C. (Division of Clinical Hematology and Oncology, Department of Internal Medicine, Huddinge Hospital and Karolinska Institute, Huddinge, Department of Medical Cell Genetics, Medical Nobel Institute, Department of Pharmacology, Karolinska Institute, and Department of Pathology, Karolinska Hospital, Stockholm, Sweden.) Low density lipoprotein receptor activity in human leukemic cells—Relation to chromosome aberrations. Chromosome analysis and low density lipoprotein (LDL) receptor activity of leukemic cells from 38 patients with acute non-lymphocytic leukemia were correlated. Clonal chromosome aberrations were found in 22 patients, and an extra chromosome 8 was found in 7 of them. LDL receptor activity was significantly higher in patients with an extra chromosome 8 than in patients with other abnormalities or a normal karyotype. Chromosome 8 may harbor genes of importance for the expression of the LDL receptor.     

Chromosome 2p linkage analysis in hereditary non-polyposis colon cancer

Abstract Hereditary non-polyposis colon cancer (HNPCC) comprises 2-6% of the total colorectal cancer burden. Two families are described that show linkage between the HNPCC susceptibility gene and the markers D2S123 and D2S119 on chromosome 2p, producing multipoint lod scores of 3.62 and 3.83, respectively, in the largest pedigree. In our third family the multipoint lod scores for D2S123 and D2S119, -2.97 and -3.12, excluded localization of a susceptibility gene in this region indicating that there is at least one more gene that causes predisposition to HNPCC. The exclusion was based on at least one genotype for an individual who had multiple primary colon and extracolonic tumours and could not be considered to have had common forms of cancer. Our results therefore encourage further gene mapping to pursue the localization of additional HNPCC genes. These findings confirm the presence of the susceptibility gene for HNPCC, COCAl, on chromosome 2p. They allow the immediate identification of a subset of HNPCC families, and provide the means for presymptomatic testing of family members if sufficient number of members are available for study.     

INFLUENCE OF APROTININ (TRASYLOL) ON THE ACTION OF SUXAMETHONIUM

Aprotinin concentrations such as occur in vivo after intravenousinjection of 100,000 KIU, inhibit ChE activity by about 5–16per cent. The degree of inhibition is greatest between 6 and20 minutes post-injection and is negligible after 30 minutes.When the ChE baseline activity is normal, 5–16 per centinhibition does not lead to a prolongation of the action ofsuxamethonium. A prolongation of the apnoeic period in connectionwith an administration of aprotinin is only possible if theChE activity is close to the critical level and is lowered byaprotinin to a range in which the breakdown of suxamethoniumis delayed. There is no reason to dispense with aprotinin inoperations in which suxamethonium has been given or must begiven. Aprotinin could lead to a lowering below the criticalthreshold only in those patients who have a pathologically depressedChE activity level and therefore are already predisposed toprolonged apnoea after suxamethonium.     

Stress fractures after surgery for osteosarcoma: scintigraphic assessment

To determine how often stress fractures occur in patients who have undergone surgery for osteosarcoma of a lower limb and to characterize such lesions, 156 bone scans obtained in 43 such patients were reviewed for bone stress. Of 43 patients who had undergone amputation or limb-preserving procedures, 42 (98%) had abnormalities on scintiscans attributable to bone stress; 31 had focal or mixed focal and diffuse lesions. Bones most commonly involved were those of the contralateral leg, pelvis, ipsilateral leg, and arms. Focal and mixed lesions seemed to be associated with increased work load on the limb involved. Findings indicated that the more active the patient, the more severe the bone stress. Because of their distribution, appearance, and intensity of tracer uptake, most stress-related lesions were readily distinguishable from bony metastases on scintiscans. Questionable lesions should be evaluated further with other imaging methods.     

Relationships between the metabolism of high-density and very-low-density lipoproteins in man: studies of apolipoprotein kinetics and adipose tissue lipoprotein lipase activity

Abstract. In order to gain further insight into the relationship between high-density lipoprotein (HDL) metabolism and plasma triglyceride transport, measurements were made of HDL cholesterol concentration, apoprotein (apo) AI and AII metabolism, very-low-density lipoprotein (VLDL) apo B metabolism, and heparin-elutable adipose tissue lipoprotein lipase (LPL) activity in seventeen subjects with a wide range of plasma triglyceride concentrations (0.8–25 mmol/l).
The fractional catabolic rate (FCR) of VLDL apo B was directly related to LPL activity ( r =+ 0.80), providing evidence that the activity of the enzyme in adipose tissue is a determinant of the rate of lipolysis of VLDL in man. HDL cholesterol concentration was a positive function of both VLDL apo B FCR ( r =+ 0.74) and LPL activity, a finding consistent with previous evidence for the origin of a proportion of HDL cholesterol from 'surface remnants' liberated during VLDL catabolism. The FCRs of both apo AI and apo AII were inversely related to VLDL apo B FCR (AI, r = - 0.52; AII, r = - 0.69) and to LPL activity. The synthetic rate of apo AII, but not that of apo AI, was positively correlated with VLDL apo B synthesis ( r =+ 0.71). Thus, the metabolism of the major proteins of HDL in man appears to be closely associated with VLDL metabolism.     

INFLUENCE OF TEACHING ON THE TRIAGE OF MULTIPLE INJURY PATIENTS

SUMMARY Attempts to improve the standard of early trauma management through the training and instruction of medical personnel have had variable results. Knowledge of trauma care is inadequate among all grades of medical and paramedical staff, and not much improvement has been made by the availability of instruction courses in trauma management. Staff most likely to attend such courses are seemingly already more proficient than staff who choose not to. To achieve maximum benefit from future courses, therefore, we believe attendance should be compulsory for all personnel involved in acute trauma care.     

The COBE Spectra cell separator is more effective than the Haemonetics MCS-3P cell separator for peripheral blood progenitor cell harvest after mobilization with cyclophosphamide and filgrastim

BACKGROUND: Peripheral blood is rapidly replacing bone marrow as a source of hematopoietic progenitor cells for autologous transplantation. The advantages of peripheral blood progenitor cell transplantation are enhanced by the ability to collect sufficient progenitor cells to ensure rapid neutrophil and platelet recovery in a single procedure on some cell separators. STUDY DESIGN AND METHODS: A prospective randomized study was undertaken to compare peripheral blood progenitor cell yields from two cell separators (MCS-3P, Haemonetics and Spectra, COBE). Fifteen consecutive patients were mobilized with cyclophosphamide 2 g per m2 (Day 0) and filgrastim 10 micrograms per kg (Days 1–11). Consecutive collections (Day 10, Day 11) were performed with each machine once: patients were randomly assigned to either machine for the initial collection. RESULTS: Collection time was longer on the MCS-3P (p = 0.001), and the volume processed was greater with the Spectra (p < 0.0001). Despite similar nucleated cell yield (p = 0.62), the yield of CD34+ cells (p = 0.001) and colony-forming units- granulocytic-monocytic (p = 0.0001) was significantly higher with the Spectra. The yield of nucleated cells per unit of blood volume processed was higher for the MCS-3P (p = 0.0007), while the CD34+ cell yield (p = 1) and colony-forming units-granulocytic-monocytic yield (p = 1) per unit of blood volume processed were similar for the two machines. The collection of CD34+ cells at levels > 2 × 10(6) per kg (p = 0.063), 5 × 10(6) per kg (p = 0.031), and colony-forming units- granulocytic-monocytic > 1 × 10(5) per kg (p = 0.25) after a single collection was superior for the Spectra. CONCLUSION: The yield of progenitor cells after collection on the Spectra was superior to that achieved with the MCS-3P, because of the larger volume of blood processed per procedure. This would permit more patients to undergo only one collection.     

Alterations in gait resulting from deliberate changes of arm-swing amplitude and phase

Objective. The purpose of the study was to reach a better understanding of the influence of arm movement in human gait.

Design. The experiment involved the adoption of different arm-swing patterns by normal subjects who walked in a gait laboratory.

Background. The reciprocal swinging of the arms in walking plays an important role in gait, but the details require further research. More insight into the role of the arm-swing in gait could be obtained by adopting different arm-swing patterns while walking at different speeds.

Method. Thirteen normal subjects were therefore requested to walk adopting different arm-swing patterns which included, one or both arms strapped to the body, full reciprocal excursion of both arms, pace walking and swinging the arms in parallel. From measurements made at different speeds of walking, regressions were calculated which made it possible to compare basal gait characteristics of the different arm patterns.

Results. Maximum velocity decreased in all cases. In the test conditions where the arms were strapped, the subjects increased velocity by increasing stride frequency more than stride length. In the other conditions the reverse was the case.

Conclusion. The experiments show that the gait pattern is very much influenced by changes in arm-swing but the effects are related to the pattern of arm-swing and the speed of walking.