Strengths-based case management. A role in addressing denial in substance abuse treatment.

A strengths-based approach to case management is being used as an intervention to assist persons with substance abuse problems to access needed resources. The same strengths-based practice activities that support resource acquisition are also effective in addressing the denial that can interfere with substance abuse treatment. Both benefits, resource acquisition and a constructive approach to denial, have shown promise for enhancing client participation in treatment and subsequent outcome from that treatment.

Common expression of the multidrug resistance marker P-glycoprotein in B-cell chronic lymphocytic leukaemia and correlation with in vitro drug resistance.

The expression of P-glycoprotein (Pgp), which is associated with multidrug resistance (MDR), was investigated in 20 B-cell chronic lymphocytic leukaemia (B-CLL) patients by flow cytometry using two Pgp-specific monoclonal antibodies (mAb), MRK-16 which recognizes an extracellular epitope, and JSB-1 which recognizes an intracellular epitope. Sixteen (80%) patients were positive with MRK-16 whereas all patients were positive with JSB-1. The proportion of Pgp-positive lymphocytes from each patient sample varied from 2-94% for MRK-16 and 20-93% for JSB-1. There was no correlation between the level of positivity and disease stage or treatment history. In vitro drug resistance to vincristine (VCR) and doxorubicin (DOX) was determined by the colorimetric MTT assay. All patients were resistant to one or both drugs being consistent with the expression of Pgp. There was no correlation between the level of resistance and disease stage or drug treatment. We investigated the expression of Pgp in the normal counterpart of the B-CLL cells, CD5+CD19+ B-lymphocytes. A minor subpopulation (3%) of CD5+CD19+ lymphocytes isolated from normal controls expressed Pgp suggesting that these cells may be the potential precursors to the B-CLL cell. We conclude that Pgp expression and drug resistance are inherent characteristics of the B-CLL lymphocyte.

The rumen microbiology of seaweed digestion in Orkney sheep.

The microbial populations of the rumens of seaweed-fed and pasture-fed Orkney sheep were examined. The populations in the pasture-fed sheep were similar to those of other domestic ruminants fed on land plants, but those of the seaweed-fed animals showed major differences in the dominant species. Total ciliate populations were quantitatively similar, but in the seaweed-fed animals Dasytricha ruminantium was one of the most dominant species. No phycomycete fungi or cellulolytic bacteria were found in the seaweed-fed animals, and the bacterial population was dominated by Streptococcus bovis, Selenomonas ruminantium, Butyrivibrio fibrisolvens and lactate-utilizing species. Electron microscopy revealed that spirochaetes and an unidentified filamentous bacterium were probably of major significance in seaweed digestion. The ability of bacterial strains from both groups of animals to metabolize plant and algal constituents was examined.

Soluble and immobilized anti-Ig antibodies in the regulation of LPS-induced lymphoblasts.

Anti-immunoglobulin (anti-Ig) causes suppression of secretion of immunoglobulin by LPS-activated pig B lymphoblasts. The cellular level at which anti-Ig influences immunoglobulin secretion has been investigated, using soluble anti-Ig which enters B cells, and anti-Ig immobilized onto acrylamide bead or plastic surfaces which can act only at the B-cell surface. Suppression of secretion only occurred with soluble anti-Ig, indicating that the intracellular processing of antibody after its complexing on the cell surface was necessary for suppression to occur. Immobilized anti-Ig acted as effectively as soluble antibody in activation of resting B cells into mitosis, showing that the activating signal of anti-Ig is received at the cell surface. Electron microscopy has shown that the block to secretion after soluble anti-Ig resulted from the accumulation of smooth membrane-bounded intracellular vesicles which, by immunofluorescence, contained immunoglobulin. The formation of vesicles was intimately associated with the intracellular localization of 125I-labelled anti-Ig which was used to follow cellular processing of anti-Ig.

The uptake and utilization of Entodinium caudatum, bacteria, free amino acids and glucose by the rumen ciliate Entodinium bursa.

Washed suspensions of Entodinium bursa were incubated anaerobically with Entodinium caudatum, ten species of bacteria and a yeast. The rate of uptake and digestion of these micro-organisms was investigated. Protozoa grown in vivo did not engulf Proteus mirabilis or Klebsiella aerogenes but rapidly took up Bacillus megaterium. Selenomonas ruminantium, Torulopsis glabrata and Streptococcus bovis, although only the last was digested with release of soluble material into the medium. Protozoa grown in vitro engulfed each of the bacteria tested, taking up Megasphaera elsdenii and Proteus mirabilis most rapidly. Individual bacterial species and mixed rumen bacteria were engulfed more rapidly (up to 20 times) by protozoa grown in vivo than those grown in vitro, although the latter digested over 80% of the B. megaterium, Escherichia coli and P. mirabilis taken up. Labelled Ent. caudatum was extensively digested after engulfment by Ent. bursa. Some of the digestion products were released into the medium but individual amino acids were transferred as such from Ent. caudatum protein to Ent. bursa protein. Engulfed bacteria and polysaccharide granules were transferred intact from one protozoon to the other. Free amino acids were also taken up intact from the medium into protozoal protein but there was little biosynthesis of amino acids from glucose. When available for engulfment Ent. caudatum was quantitatively a much more valuable source of amino acids for protein synthesis by Ent. bursa than free amino acids or bacteria.

Ultrastructural studies of the free zoospore of the rumen phycomycete Neocallimastix frontalis.

The structure of the free zoospores of Neocallimastix frontalis has been examined by electron microscopy of thin-sectioned and negatively stained preparations. There are up to 15 flagella arranged in two rows. The free end of each flagellum is narrow and its tip does not contain microtubules. The flagella and the cell body are coated with distinct surface layers composed of regular arrays of particles and fibrils, respectively. The cell body contains a variety of inclusions. Near to the flagellar pole there are numerous membrane-bound electron-dense globules about 0.2 to 0.7 mum in diameter, between which are microtubules, particles and small vesicles. In the region of the centrally placed nucleus are arrays of helices of ribosome-like particles. These particles also occur in the form of globular aggregates, each partially enclosed within a membrane. The remainder of the cytoplasm is filled with material resembling glycogen. The zoospores stain positively for glycogen and contain ribonuclease-sensitive particulate material which is stained by toluidine blue. Scanning electron microscopy shows that the zoospores attach to the substrate by the flagellar pole.

Studies in the electron microscope of the adoral zone of membranelles of the rumen ciliate entodinium caudatum using the technique of negative staining.

The structure of the organelles situated beneath the kinetosomes in the adoral zone of membranelles of the rumen ciliate Entodinium caudatum have been investigated in the electron microscope using the technique of negative staining. Each kinetosome was joined to a sub-kinetosomal plate and these plates were joined together in rows which in turn were more loosely linked to form a sheet. The structure or these plates is described and their relationship to similar structures in other protozoa is discussed. The nature of the argentophilic structures observed in the light microscope at the anterior end of Entodinium caudatum has also been investigated in the electron microscope.

Electron microscopy of the rumen ciliate Entodinium caudatum, with special reference to the engulfment of bacteria and other particulate matter.

A study in the electron microscope of thin sections of the rumen ciliate Entodinium caudatum was undertaken in an attempt to elucidate the mode of engulfment of particulate matter. This protozoon engulfed bacteria, polystyrene latex particles and olive oil into membrane-lined vesicles in the protozoal endoplasm. Particles of palladium black were also taken up into the endoplasm, but due to the toxic nature of this material it was not possible to demonstrate vesicle formation with certainty. The initial uptake of bacteria may be into large sacs containing many organisms which were subsequently taken into the endoplasm in vesicles that contained only one bacterium each. The evidence obtained in this investigation has been used to distinguish between two different mechanisms for the digestion of bacteria and utilization of the amino acids from the bacterial protein for the synthesis of protozoal protein.