Osteoclasts contain macrophage and megakaryocyte antigens

The origin and mechanism of formation of the osteoclast remains controversial. Although it is known to be derived from a circulating mononuclear percursor, the identity of this cell is unknown. Using a panel of monoclonal antibodies raised against macrophage and other marrow-derived cells, we determined the immunocytochemical staining of human osteoclasts in both fetal bone metaphyseal imprints and frozen sections. Osteoclasts and marrow mononuclear cells were stained by three broad spectrum antimacrophage antibodies, EBM-11, Y182a and BM2. T310, an antibody which stains macrophages and T helper cells, and C17, an antimegakaryocyte antibody, also stained osteoclasts. EBM-11, Y182a and BM2 also stained megakaryocytes in bone imprints as well as normal bone marrow smears. The presence of macrophage-associated antigens in osteoclasts, megakaryocytes and bone marrow mononuclear cells indicates that they are phenotypically similar to macrophages.

MRI simulator for instruction in pulse-sequence selection

An ordinary desk-top microcomputer was programmed to simulate MR images for specified spin-echo pulse sequences. Model pixel maps of proton density and T1 and T2 relaxation times were made from published estimated values for regions of the human head, neck, and spine. Images were generated and displayed from the model maps and user-specified pulse-sequence parameters in less than 30 sec/image. Models for various pathologic conditions, including calcification, subacute hemorrhage, porencephaly, lipoma, and multiple sclerosis, were superimposed on the images of normal anatomy to create unknown cases. Simulated images can easily demonstrate the effect of pulse-sequence selection on the contrast of normal structures and pathologic conditions. Use of simulated images is an excellent technique for gaining experience in pulse-sequence selection. Low-cost microcomputers can provide adequate image detail and reasonable image display time of synthetic MR images for teaching purposes.

Cortisol kinetics and fluid distribution in brook trout (Salvelinus fontinalis)

Cortisol kinetics were examined in brook trout (Salvelinus fontinalis) to assess possible relationships with body fluid distribution during acclimation to sea water (SW). The disappearance curve of [3H]cortisol in plasma, after a bolus injection, was analysed by compartmental analysis using a three-pool mammillary model. The results indicated that only approximately 10% of the total exchangeable cortisol was located in the plasma pool. Over 75% of the total cortisol was associated with a large slowly exchanging pool and the remaining cortisol was located in a second extravascular tissue pool which was in rapid exchange with the plasma pool. Two days after transfer of trout from fresh water to SW, when plasma chloride concentration was at a new steady state, body weight, intracellular fluid volume, haematocrit and inulin clearance rate were lowered but plasma, blood and extracellular volumes were unaltered. Cortisol plasma clearance rate was unaltered but plasma cortisol concentration, cortisol secretion rate, total cortisol pool size and interpool transport rates were increased. These results are consistent with an acute role for cortisol in SW adaptation of brook trout. The fraction of the total cortisol cleared was smaller and the average time that cortisol spent in the tissue pools was slightly longer in trout after transfer to SW, possibly reflecting altered fluid dynamics. The fractional disappearance rate was larger at higher plasma cortisol concentrations in the SW trout. This relationship is compatible with the hypothesis that cortisol protein binding protects cortisol from metabolism.

Use of physician-hired nurses. A survey

The results of a survey conducted on the practice of using physician-hired nurses in hospitals are reported. Nursing administrators need information on the nursing services that are being provided in direct association with the medical practice of physicians, particularly when those services influence the quality and cost-effectiveness of patient care. The information can be used to plan more effective approaches to the delivery of nursing health care services.

A unique approach to performance standards for clinicians in a CMHC

Performance standards were developed for clinicians of a large comprehensive mental health center. Clinicians were required to provide a minimum average of 20 hours of face-to-face service per week. Credit values, ranging from .5 to 3.0, were assigned for each hour of service provided based on the difficulty of the service to deliver and the amount of paperwork required. Total credits were considered as an extra accomplishment and utilized as a criterion for determining merit increases. The results indicated an increase in the utilization of family and group therapy as well as a more equitable system for evaluating widely differing services.

Ensuring quality of care in a comprehensive mental health center

A six-phase process is currently being utilized by a large comprehensive mental health center to ensure delivery of the highest quality of care to its patients. In the first phase, during the admission process, each patient's assets and liabilities are determined. The second phase involves a disposition team that reviews and assigns each case. The third phase involves both the clinician and patient in developing a treatment plan. The fourth phase is a periodic review of each patient's file by the clinician's supervisor. The fifth phase involves a peer review of randomly selected files. The final phase is a retrospective review of randomly selected patients who are no longer receiving services, comparing the current assets and liabilities with those on the initial assessment to determine if progress did occur and was sustained.

Use of terminal deoxynucleotidyl transferase in the diagnosis of leukemia

Terminal deoxynucleotidyl transferase (TdT) was determined by immunofluorescence in 30 patients with leukemia. In acute lymphocytic leukemia the proportion of cells positive for TdT was 19 to 77 percent during relapse (12 cases) and less than one percent during remission (three cases). In seven cases of myeloproliferative disease and two cases of lymphoma, the TdT was less than one percent. In one case of generalized lymphoblastic lymphoma and five cases of chronic myelocytic leukemia with "lymphoblastic" crisis, the cells positive for TdT were moderately increased. The presence of TdT in blast cells appears to have diagnostic, therapeutic, and prognostic significance.

Assessment of a pilot child playground injury prevention project in New York State

Following a child playground equipment injury prevention project conducted in New York State in 1977, there was a 42 per cent reduction in playground equipment hazards, and a 22.4 per cent reduction in playground related injuries treated in the two largest hospitals of one of the program sites. Knowledge about unsafe playground practices and equipment hazards improved after the workshops for playground personnel. This approach to injury prevention deserves further study.

The use of leukocyte acid phosphatase in the diagnosis of malignant disease. Case report and review of literature

Tartrate resistant acid phosphatase (TRAP) has been demonstrated during relapse in the cells in the cerebral spinal fluid (CSF) in a patient with the clinical features of acute T cell lymphocytic leukemia which suggests this isozyme may be a marker for malignant transformation of some types of lymphocytes. The presence of TRAP may be helpful in establishing the diagnosis of a lymphocytic malignancy since normal lymphocytes appear to have tartrate sensitive acid phosphatase. The presence of TRAP can no longer be considered specific for hairy cell leukemia, since children with acute lymphocytic leukemia are being found with this isozyme in their malignant blasts. The presence of TRAP does not appear to be specific for T or B cell lines of malignant lymphocytes since it has been described in cells with either type of cell markers. The presence of TRAP seems most useful in differentiating lymphocytic malignancies from monocytic and histiocytic malignancies and from benign lymphocytoses when the cells of the peripheral blood and marrow may have similar morphologic features with routine staining.

The relationship between some measures of synaptic ultrastructure as a function of distance from the soma on lamprey reticulospinal neurons

Synaptic junctions located on the dendrites of lamprey (Petromyzon marinus) reticulospinal neurons labelled with intracellularly-injected horseradish peroxidase were studied. The normal ultrastructure of the synaptic junctions was defined and several quantitative measures made from each junction in order to test the hypothesis that distally-located synapses are ultrastructurally different from those located at proximal dendritic sites. A total of 820 contacts from one neuron and 279 from a second neuron ranging from 20 to 340 microns from the soma were quantified. The vast majority of the presynaptic endings contained round, clear-cored vesicles and formed an asymmetrical membrane differentiation with the postsynaptic dendrite. A small fraction of the population contained flattened or pleomorphic vesicles and these synapses were equally distributed with respect to distance from the soma. Many of the terminals contained a few large dark- and clear-cored vesicles. Four quantitative measures of each synaptic contact were made. These included vesicle number, length of differentiated membrane, vesicle area and terminal area. Four ratios relating the different quantitative measures were also calculated. Each ratio or measurement from the synaptic junctions was plotted as a function of distance from the soma to determine if differences existed at any distance. It was found that synaptic junctions are uniformly similar and that distal junctions did not differ significantly (P greater than 0.05) from those at proximal dendritic sites. It is concluded that if distal synapses do compensate for their remote location they do this is some other way, possibly by increasing the number of synaptic contacts made by each presynaptic axon.