Activation of protein kinase C results in the displacement of its myristoylated, alanine-rich substrate from punctate structures in macrophage filopodia

The myristoylated, alanine-rich C kinase substrate (MARCKS) is a prominent substrate for protein kinase C (PKC) in a variety of cells, and has been implicated in diverse cellular processes including neurosecretion, fibroblast mitogenesis, and macrophage activation. In macrophages that have spread on the substratum, MARCKS has a punctate distribution at the cell-substratum interface of pseudopodia and filopodia. At these points, MARCKS co-localizes with vinculin and talin. Activation of PKC with phorbol esters results in the rapid disappearance of punctate staining of MARCKS, but not vinculin or talin, and is accompanied by cell spreading and loss of filopodia. The morphological changes and disappearance of punctate staining follow a time-course that closely approximates both the PKC-dependent phosphorylation of MARCKS, and its phosphorylation-dependent release from the plasma membrane. Our results suggest a role for PKC-dependent phosphorylation of MARCKS in the regulation of the membrane cytoskeleton.     

Immunophenotyping in the diagnosis and classification of acute lymphoblastic leukemia

The identification of ALL immunophenotypes with distinctive clinical features and prognostic significance indicates the importance of these studies in the evaluation of ALL patients for both clinical and research purposes. For differential diagnosis, the expression of pan-B-cell or pan-T-cell lymphoid antigens and the absence of myeloid/monocyte antigens represent the most useful markers for distinguishing ALL from AML. However, the increasing appreciation of large numbers of patients with clinically significant mixed lymphoid-myeloid phenotypes suggests that rigid classification of acute leukemias into exclusive lymphoid and myeloid categories may be somewhat artificial. In adult ALL, patients with My+ phenotypes (B+sIg-T-My+ and B-sIg-T-My+) have a lower incidence of complete remission and shorter survival times than do patients with My- marker profiles. Preliminary studies in childhood ALL also suggest a correlation between myeloid antigen expression and poor prognostic factors. In addition, children with sIg+ "B-cell," cIg+ "pre-B-cell," and T-cell ALL phenotypes have shorter disease-free survival times than do patients with more common "early pre-B" (B+cIg-sIg-T-) marker profiles. Application of immunologic markers in concert with cytogenetic and gene rearrangement studies has led to the identification of novel subgroups of leukemia with distinct clinical characteristics. Future studies incorporating a multiparameter diagnostic approach including immunophenotyping, gene rearrangement studies, and karyotypic analyses should further our understanding of the heterogeneity of acute leukemias, guide the development of new therapeutic strategies, and provide for more clinically relevant classification of these disorders.     

Outcomes of Total Hip Arthroplasty in Spastic Patients

Patients with spasticity and hip arthritis can present challenges to treatment. This investigation evaluated the effectiveness and safety of THA in patients with upper motor neuron disease. Twenty-seven consecutive patients with history of cerebral palsy (CP) or acquired spasticity (AS) underwent 30 THAs for treatment of hip arthritis. They were followed for an average 2.5 years (range 2.1–12.1). Patients with CP were more likely to require hip adductor release and hip flexor lengthening at the time of THA. Statistically significant improvements were made in Harris Hip Scores, pain scores, range of motion, ambulatory status, and the use ambulatory-assistive devices. There were no dislocations in this group. Patients with spasticity can benefit from THA in terms of pain relief and improved mobility with relatively low complications.     

Pulmonary function in alcoholics

Twenty-three chronic alcoholics were investigated by means of pulmonary function studies. All 23 patients had respiratory symptoms. Clinically, 21 (91 per cent) of 23 patients were diagnosed as having chronic bronchitis, and 14 patients (60 per cent) had dyspnea. The maximal mid-expiratory flow and single breath diffusing capacity for carbon monoxide (SBDCO) were abnormal in 16 (70 per cent) and 14 (61 per cent) patients, respectively. Twenty-two of 23 patients had one or more abnormal function. The total lung capacity, residual volume, vital capacity, 1 second forced expiratory volume and SBDCO progressively declined with increasing alcohol consumption. An attempt was made to separate the pulmonary effects of alcohol from (1) the effects of previous pulmonary infections, (2) the effects of cigarette smoking, and (3) the effects of cirrhosis of the liver. The data suggest that either alcohol itself through some unknown mechanism may be a causative agent in producing lung disease or that alcohol makes a higher percentage of the population susceptible to the harmful effects of cigarette smoking.     

Manual dexterity as a correlate of dependency in the elderly

Physical and mental correlates of dependent living were determined in 128 Catholic sisters (nuns), aged 75 to 94 years, who had similar social support systems and lifestyles. The primary a priori hypothesis was that poor manual dexterity would correlate strongly with living in the nursing home. Stepwise discriminant analysis indicated that manual dexterity explained 51% of the variance in the sisters' residential living site (ie, nursing home, retirement home, or living in community). The discriminant analysis equation using manual dexterity predicted living site correctly for 63% of the sisters in the nursing home with a specificity of 99%, a positive predictive value of 96% and negative predictive value of 84%. The addition of age and mental status to the equation improved the prediction only slightly.