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A somatic mutation within a microsatellite polyA tract in the coding region of the type II transforming growth factor (TGF)-beta receptor gene was reported to occur in human atherosclerotic and restenotic lesions. This mutation occurs frequently in colorectal cancer with the replication error repair phenotype and results in loss of sensitivity to the growth inhibitory effects of TGF-beta in cells from the tumors. The mutation was proposed to account for the clonal expansion of vascular smooth muscle cells observed in atherosclerotic plaques, through loss of the growth inhibitory effect of TGF-beta. The frequency of the mutation and the extent of clonal expansion of the mutated cells have major implications for the mechanism of atherogenesis and therapeutic strategies. We analyzed a set of 22 coronary arterial and 9 aortic samples containing early to advanced atherosclerotic lesions for the mutation in the type II TGF-beta receptor polyA tract. Only 1 coronary arterial sample from an advanced lesion showed detectable amounts of the mutation, present at a low level (8% of the DNA sample). The data imply that the mutation occurs only at low frequency and is not a major mechanistic contributor to the development of atherosclerosis.

The V kappa10 family of murine light chain Ig genes is composed of three members, two of which (V kappa 10A and V kappa 10B) are well used. V kappa 10C, the third member of this family, is not detected in any expressed Abs. Our previous work showed that V kappa 10C is structurally functional and can recombine, but mRNA levels in spleen were extremely low relative to those of V kappa 10A and V kappa 10B. Furthermore, while the V kappa 10C promoter was efficient in B cells, it was shown to work inefficiently in pre-B cell lines. Here, we extend our analysis of the V kappa 10 family and examine V kappa 10 gene accessibility, their representation in V kappa cDNA phage libraries, and the frequency and nature of rearrangements during different stages of B cell development. We demonstrate that V kappa 10C is under-represented in V kappa cDNA libraries, but that the frequency of its sterile transcripts in pre-B cells surpasses both V kappa 10A and V kappa 10B, indicating that the gene is as accessible as V kappa 10A and V kappa 10B to the recombination machinery. We also demonstrate that V kappa 10C recombines at a frequency equal to that of V kappa 10A in pre-B cells and has a normal nonproductive to productive recombination ratio. As B cells develop, however, both the frequency of V kappa 10C rearrangements and the presence of productive rearrangements decline, indicating that these cells are in some fashion being eliminated.

We describe a monoclonal antibody, mAb 90.12, which recognizes a novel activation induced lymphocyte surface antigen. Flow cytometric analysis of normal tissues shows the antigen to be expressed on higher percentages of B lymphocytes in the bone marrow than in the spleen and the lymph node. Similarly, the 90.12 antigen is expressed on higher percentages of thymocytes than peripheral T cells. MAb 90. 12 immunoprecipitates three proteins with a molecular weight of 12-18 kDa which are not linked to the membrane by phosphotidylinositol. Expression of the 90.12 antigen is increased on activated B cells and the extent of upregulation varies with the stimulus. Lipopolysaccharide (LPS) stimulation results in expression on most B cells, while expression is upregulated on only a subset of B cells stimulated with anti-immunoglobulin M (IgM), interleukin(IL)4 and IL5. Finally, we show that 90.12 antigen expression is also increased on apoptotic cells.

The regulation of protein synthesis is critical to diverse cellular processes and plays a pivotal role in regulating gene expression during embryogenesis. The cap-binding protein eIF4E is a translational factor whose activity appears to be both ubiquitous and central to the regulation of protein synthesis in all cell-types. As a cell-cycle regulator, mesoderm inducer and proto-oncogene, the amount and activity of the translational factor eIF4E must be under strict control, but the range of its expression and its concentration as a function of position and time in the developing embryo are unknown. Consequently, we have initiated studies to elucidate the expression of the eIF4E gene and its role in the regulating embryonic development. We have cloned a zebrafish gene encoding eIF4E, zeIF4E, and measured its developmental expression. Unexpectedly, we found that the zeIF4E gene produces two alternatively spliced transcripts that potentially encode different forms of the initiation factor. Molecular analyses and in situ hybridization reveal a potential role for eIF4E in regulating protein synthesis during vertebrate oogenesis, gastrulation, and erythropoiesis. The dynamic and asymmetric expression of eIF4E during zebrafish embryogenesis reveals that this ostensibly general translation factor may act as a tissue-specific translational enhancer.

Relatively little is known about the molecular mechanisms of tumor promotion/progression in mammary carcinogenesis. Increased protein kinase C (PKC) activity is known to promote tumor formation in several tissues; however, its role in mammary carcinogenesis is not yet known. To determine if individual PKCs may selectively regulate properties of mammary tumor cells, we compared PKC isozyme levels in mammary tumor cell lines with low, moderate and high metastatic potential. All three cell lines expressed alpha, delta, epsilon and zeta PKCs; however, PKC delta levels were relatively increased in the highly metastatic cells. To determine if increased PKC delta could contribute to promotion/progression, we overexpressed PKC delta in the low and moderately metastatic cell lines. PKC delta overexpression had no significant effect on growth of adherent cells, but significantly increased anchorage-independent growth. Conversely, expressing the regulatory domain of PKC delta (RD delta), a putative PKC delta inhibitory fragment, inhibited anchorage-independent growth. The efficacy of RD delta as a PKC delta inhibitor was demonstrated by showing that RD delta selectively interfered with PKC delta subcellular location and significantly interfered with phosphorylation of the PKC cytoskeletal substrate, adducin. PKC-dependent phosphorylation of cytoskeletal substrate proteins, such as adducin, provides a mechanistic link between increased PKC delta activity and phenotypic changes in cytoskeletal-dependent processes such as migration and attachment, two processes that are relevant to metastatic potential. The reciprocal growth effects of expressing PKC delta and RD delta as gain and loss of function constructs, respectively, provide strong evidence that PKC delta regulates processes important for anchorage-independent growth in these mammary tumor cells.

Internal ribosome entry sites (IRESs) allow ribosomal access to messenger RNA without a requirement for cap recognition and subsequent scanning to an initiator AUG. Hence, IRESs have been adapted into dicistronic vectors for the expression of more than one gene from a single mRNA. Dicistronic vectors have been used for many applications in mammalian tissue culture and transgenesis. However, whether the IRESs from mammalian viruses function without temporal or spatial restrictions in nonmammalian organisms like zebra fish (Danio rerio) is unknown. Therefore, we have examined the expression capabilities of the encephalomyocarditis virus (EMCV) IRES during zebrafish embryogenesis. We determined that the EMCV IRES was sufficient to permit detectable expression of several second cistron reporters during zebrafish embryogenesis, including luciferase and green fluorescent protein. This suggests that our dicistronic vectors are suitable for general use in any vertebrate system, from fish to humans.

The S100 proteins comprise a large sub-family of the EF-hand calcium-binding proteins. Here we describe a novel monoclonal antibody recognizing a B cell surface antigen. This monoclonal antibody immunoprecipitates three proteins in the 12-18 kDa range and the smallest of these proteins has a striking homology at its amino-terminus to human MRP8, a myeloid specific member of the S100 family. Similarly to MRP8 in myeloid cells, this antigen is expressed in the cytoplasm of B cells and is secreted by LPS-induced activated B cells. This surface antigen is not B cell specific. Since MRP8 is not expressed by lymphoid cells, however, this antibody appears to recognize a new member of the S100 family., (Copyright 1999 Academic Press.)

Metastasis requires cytoskeletal remodeling for migration, adhesion, and extravasation of metastatic cells. Although protein kinase C (PKC) is involved in tumor promotion/progression and cytoskeletal remodeling, its role in metastasis has not been defined. PKCdelta levels are increased in highly metastatic 13762NF mammary tumor cells (MTLn3) compared with less metastatic, parental cell lines. To determine whether the increase in endogenous PKCdelta is functionally related to their increased metastatic potential, we prepared MTLn3 cells that express the inhibitory regulatory domain fragment of PKCdelta (RDdelta) under the control of a tetracycline-inducible promoter. RDdelta expression attenuated endogenous PKCdelta activity, as demonstrated by decreased phosphorylation of the PKCdelta substrate adducin in migrating cells. Thus, in MT cells, RDdelta appears to primarily influence cytoskeleton-dependent processes rather than cell cycle progression. To determine whether RDdelta expression influenced metastatic potential in vivo, MTLn3/RDdelta cells were either grown in the mammary fat pad or injected into the tail vein of syngeneic rats, and effects of doxycycline-induced RDdelta expression on pulmonary metastases were studied. Consistent with the in vitro data, induction of RDdelta significantly reduced the number of lung metastases without affecting growth of the primary tumor. These results suggest that interfering with endogenous PKCdelta activity by expressing the inhibitory RDdelta fragment inhibits cytoskeleton-regulated processes important for MTLn3 cell metastasis.

Rotaviruses are the leading cause and coronaviruses are the major contributors of acute gastroenteritis in the young of various mammalian and avian species. Despite numerous trials and decades of research, vaccines have limited efficacy particularly for calves. As an alternative method of controlling infection, we have investigated broad spectrum antiviral agents that are not discriminatory among various viruses. This report involves testing a variety of adsorbent agents including charcoal, clay, and clay minerals to adsorb rotavirus and coronavirus in vitro. Results revealed that all the adsorbent agents had good to excellent capability of adsorbing rotavirus and excellent capability of adsorbing coronavirus. Percent adsorptions ranged from 78.74% to 99.89% for rotavirus and 99.99% for coronavirus; while sand (negative control) was < 0.01%. A high affinity binding was present as determined by a low percent desorption (0.06-3.09%). However, the adsorbent bound virus complex retained, and may have actually enhanced, infectivity.

Crude theaflavin was extracted from black tea and then fractionated by HPLC into five components (initial peaks (IP), TF1, TF2A, TF2B, and TF3). The crude extract and the various fractions of theaflavin were collected and tested, individually and in combination, for antirotaviral activity. The mean effective concentration (EC50) was calculated and compared. Activity varied from the most active being the uncharacterized theaflavin-like initial peaks (IP) with an EC50 of 0.125 microgram/ml to the least active being theaflavin-3 monogallate (TF2A) with an EC50 of 251.39 micrograms/ ml. The combination of TF1 + TF2A + TF2B + TF3 was more active than the sum of the activities of these four fractions individually, indicating synergism among the peaks. Only the crude extract was assayed for activity against coronavirus; the EC50 was 34.7 micrograms/ml.

Production in US aquaculture is limited by the few FDA-approved drugs available for use. The problem is compounded by the high costs and long time frames associated with extending the approved label of an existing drug to treat additional fish species. An FDA approved crop grouping plan could significantly reduce the costs associated with extending or expanding the label of a currently approved drug to other species. Before FDA could sanction such a plan, they require scientific data with which to make an informed decision. Under a crop grouping plan, a surrogate fish species would represent a single group of fish for the purposes of gaining drug approvals. The concept, if practical, would conserve substantial public resources expended to gain drug approvals and yet give regulators assurance that the extended label use provides necessary regulatory safeguards to protect human food safety and the environment. A crop grouping plan should include development of a data base that is sufficiently sensitive to discriminate differences of one group from another and yet would be able to identify potential similarities between like-species for grouping. The proposed crop grouping action plan should include data sets for fish grouped by temperature preference, activity level, and phylogenetic classification. Initially, two representative species would be identified for testing as surrogates for candidate groups; rainbow trout representing a coldwater, active, and conservative phylogenetic group, and channel catfish representing a warmwater, relatively sedentary and more phylogenetically advanced group. Additional species representing more primitive (sturgeon) and more advanced (striped bass and walleye) groups would be added. A waterborne (benzocaine) and an orally administered drug (sarafloxacin) would initially be tested among the major species groups. The integrity of the group will be tested by comparing the variability of response between major species against variability within cohort species identified for inclusion within each specific group.

The purpose of this study was to compare needle detection using a commercially available vibrating needle system that is used with color Doppler sonography and conventional real-time needle guidance during ultrasonographically guided intervention. Twenty-four paired (48 total) sonographically guided needle placements were performed in 22 patients for fine needle biopsy. Two patients underwent two additional needle placements at later times and, therefore, underwent a total of four needle passes each. Twenty-four of the needles were placed utilizing conventional real-time ultrasonographic guidance, and 24 were guided using a commercially available vibrating needle system. The Color Mark System was compared with standard technique for needle visualization and graded according to ease of needle visualization (improved, no change, or more difficult visualization). This was done for both needle tip and needle shaft visualization. Visualization was graded in both superficial (less than 3 cm deep) and deep structures. Overall needle tip and shaft visualization improved in 14 of 24 cases in superficial tissues and in three of 24 cases in superficial and deep tissues with the Color Mark System. The vibrating needle system also was judged to be somewhat cumbersome when used with a 22 gauge needle, as its weight tended to bend the needle shaft. The needle vibrating system may enhance needle visualization in superficial structures, but with the present design it is of limited use in deep tissues.

During the 1992 and 1993 breeding seasons, epidemics of diarrhea among calves approximately 3 months old in a cow/calf operation were reported. Rotavirus was determined to be the probable cause, but because rotavirus typically affects younger calves, further investigations were conducted to determine the characteristics of the virus. Virus isolated from the feces of 1 affected calf was found to be antigenically distinct from the vaccine strain used. The primary water source was a slough, and rapid spread of infection may have been a result of fecal contamination of the slough. In both years, the epidemic began shortly after migrating cattle egrets arrived in the district.

The purpose of this study was to assess the potential application of color Doppler sonography in thyroid imaging. Thyroid nodules and other thyroid pathology detected by color Doppler ultrasound and nuclear scintigraphy were compared in 115 patients. The majority of "cold" nodules demonstrated a peripheral rim of color flow and no internal color flow with color Doppler sonography. A large number of "hot" nodules demonstrated internal color flow. Color Doppler sonography was helpful in delineating nodules in otherwise inhomogeneous glands. We determined that color Doppler cannot reliably distinguish benign from malignant thyroid nodules; fine-needle aspiration biopsy remains the most accurate method in differentiating benign and malignant lesions. We suggest that color Doppler sonography plays only a limited role in the evaluation of nodular thyroid disease at this time. The color Doppler appearance of other thyroid disorders (including toxic multinodular goiter, Graves' disease, and thyroiditis) is discussed.

The effect of alkylglycerol supplementation on protein kinase C (PKC)-mediated signaling events has been studied in fibroblasts from Zellweger patients (SF 3271 cells). Western blotting analysis established that Zellweger fibroblasts express PKC alpha, epsilon, and zeta. Incubation with bradykinin induced a rapid transient translocation of PKC alpha and a more sustained translocation of PKC epsilon to the particulate fraction; translocation of PKC zeta was unaffected. Bradykinin-induced translocation and activation of PKC alpha, but not translocation of PKC epsilon, was blocked in SF 3271 cells which had been incubated with 1-O-hexadecylglycerol (1-O-HDG; 20 micrograms/ml) for 24 h and then incubated in the absence of 1-O-HDG and serum for a further 24 h. Supplementation with 1-O-HDG increased the mass of ether-linked phospholipid. Bradykinin initiated a transient increase in cytosolic Ca2+ concentration in both control and 1-O-HDG supplemented cells, indicating that the initial receptor linked events were not affected by 1-O-HDG supplementation. Bradykinin also caused a rapid activation of phospholipase D (PLD), measured by phosphatidylbutanol accumulation, and mitogen-activated protein kinase (MAPK) determined by myelin basic protein phosphorylation of Mono Q fractions. Both events were blocked by preincubation of the cells with 12-O-tetradecanoylphorbol-13-acetate for 24 h to deplete PKC protein. 1-O-HDG supplementation prevented the bradykinin-induced activation of PLD, but had no effect on the stimulation of MAPK activity. These results establish that modulation of the ether lipid composition of membranes can alter PKC isozyme translocation and indicate that a PKC isozyme other than PKC alpha, most likely PKC epsilon, is involved in MAPK activation.

Lysophosphatidic acid (LPA) was shown to be a powerful inhibitor of gap-junctional communication between cultured rat liver WB cells, as determined by the transfer of Lucifer Yellow, with 50% inhibition obtained at about 0.3 microM LPA. Inhibition of communication was rapid (5 min) and was maintained for at least 80 min. After incubation for 3 h with LPA, communication competence was partially restored and dye transfer was refractory to further addition of LPA. Communication in LPA-refractory cells retained sensitivity to inhibition by phorbol ester and by epidermal growth factor (EGF). LPA-induced inhibition was associated with phosphorylation of connexin-43 protein, as detected by slower migration of the protein detected on Western blots, which could be eliminated by incubation of samples with alkaline phosphatase. A close correspondence was observed between the time- and dose-dependency of LPA effects on communication and the induction of mitogen-activated protein kinase (MAP kinase). Activation of both the 42 kDa and 44 kDa subspecies were confirmed by mobility shifts on Western blots using an anti-(MAP kinase R1) (erk 1-III) antibody and by fractionation on Mono Q columns. Cells pretreated with phorbol ester for 24 h were insensitive to phorbol ester inhibition of communication or activation of MAP kinase, but retained their sensitivity to LPA. The results indicate that LPA initiates the activation of protein kinase cascades in WB cells that are probably independent of protein kinase C and identifies connexin-43 as one substrate for the activated kinases.

This study surveyed registered diplomates of the American Board of Sexology on neglected areas in sex research. Three rounds of questionnaires were completed by the diplomates as they identified and narrowed the most neglected sexual research questions. Results indicate that among three of the four specialty groups, marital sexual behavior was ranked as the most neglected sex research subject in the literature. In reviewing the individual research questions under each subject, more outcome studies on the treatment of various sexual disorders and dysfunctions were identified and ranked consistently higher than any questions under another subject area. The single exception was among sex educators, where individual research questions concerning sex education received the highest priority. These findings may suggest the need for new directions in sex research.

A variety of fatty acids including the cis-polyunsaturated very-long-chain fatty acids (VLCFA) (> 22 carbon atoms) common in retina, spermatozoa, and brain were examined for their ability to activate protein kinase C (PKC) purified from rat brain. Arachidonic [20:4(n-6)], eicosapentaenoic [20:5(n-3)], and docosahexaenoic [22:6(n-3)] acids as well as the VLCFA dotriacontatetraenoic [32:4(n-6)] and tetratriacontahexaenoic [34:6(n-3)] were equally capable of activating PKC in vitro with maximal activity being between 25 and 50 microM. The phorbol ester 12-O-tetradecanoylphorbol 13-acetate further enhanced the in vitro activation of PKC when added to the protein kinase assay system with the fatty acids. The fully saturated arachidic acid (20:0) was inactive in both assay systems. The potential significance of the in vitro activation of PKC by the VLCFA is discussed.

The directional properties of hydrogen bonds play a major role in determining the specificity of intermolecular interactions. An energy function which takes explicit account of these properties has been developed for use in the determination of energetically favorable ligand binding sites on molecules of known structure by the GRID method (Goodford, P.J.J. Med. Chem. 1985, 28, 849. Boobbyer, D.N.A.; Goodford, P.J.; McWhinnie, P.M.; Wade, R.C.J. Med. Chem. 1989, 32, 1083). In this method, the interaction energy between a target molecule and a small chemical group (a probe), which may be part of a larger ligand, was calculated using an energy function consisting of Lennard-Jones, electrostatic, and hydrogen bond terms. The latter term was a function of the length of the hydrogen bond, its orientation at the hydrogen-bonding atoms, and their chemical nature. We now describe hydrogen bond energy functions which take account of the spatial distribution of the hydrogen bonds made by probes with the ability to form two hydrogen bonds. These functions were designed so as to model the experimentally observed angular dependence of the hydrogen bonds. We also describe the procedure to locate the position and orientation of the probe at which the interaction energy is optimized. The use of this procedure is demonstrated by examples of biological and pharmacological interest which show that it can produce results that are consistent with other theoretical approaches and with experimental observations.

The fatty acid composition of erythrocyte total lipids taken from a group of term infants 10 weeks after being fed a commercial infant formula with a high ratio of linoleic acid (18:2n-6) (LA) to alpha-linolenic acid (18:3n-3) (ALA) (19:1; LA, 14%; ALA, 0.7%; group A, n = 10) was compared with the fatty acid composition of erythrocytes from infants fed formulas that contained LA/ALA ratios reduced by either increasing ALA (4:1; LA, 13%; ALA, 3.3%; group B, n = 11) or decreasing LA (3:1; LA, 3.5%; ALA, 1.1%; group C, n = 8). Results were compared with those in an age-controlled group (n = 9) of breast-fed infants. Decreasing the LA/ALA ratio increased n-3 C20 and C22 fatty acid incorporation (formula B = 8.98% +/- 0.65%; formula C = 9.30% +/- 0.95%) relative to formula A (5.97% +/- 0.76%; p less than 0.05). Although docosahexaenoic acid (22:6n-3) (DHA) incorporation was highest in infants fed formulas B and C (4.78% +/- 0.45% and 4.48% +/- 0.49%, respectively) relative to formula A (3.47% +/- 0.46%; p less than 0.05), it did not reach levels found in breast-fed infants (6.55% +/- 1.23%; p less than 0.05). In addition, levels of arachidonic acid (20:4n-6) (AA) were lower in all formula-fed groups (p less than 0.05) relative to those in breast-fed infants. Based on some equations, it is predicted that AA levels in tissues of infants fed lower LA/ALA ratios would be reduced even further. Because both AA and DHA are probably essential for normal neural development of the infant, formulas with LA/ALA ratios below 4:1 are likely to result in fatty acid profiles notably different from those of breast-fed infants.

Protein kinase C purified from the brains of rats killed by decapitation contained isozymes -alpha, beta and -gamma, whereas brain from animals killed by CO2-anoxia contained only the -alpha and -beta forms. Immunoblotting experiments established that exposure to CO2 resulted in a selective loss of protein kinase C-gamma protein.

The effects of 12-O-tetradecanoylphorbol 13-acetate (TPA) on the metabolism of ester- and ether derivatives of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were studied in HeLa and HEL-37 cells. TPA stimulated the incorporation of [3H]choline into diacyl-, alkylacyl- and alkenylacy/PC in HeLa cells, but inhibited the incorporation of [3H]ethanolamine into the corresponding derivatives of PE. TPA also stimulated the incorporation of [3H]ethanolamine into lysoPE and the release of labelled ethanolamine and phosphoethanolamine from HeLa cells prelabelled with [3H]ethanolamine. All responses to TPA were abolished in HeLa cells preincubated with the phorbol ester and which were deficient in protein kinase C. In HEL-37 cells TPA stimulated label incorporation into both ester- and ether-forms of PE. The marked effects of TPA on ether-lipid metabolism raises the possibility that hydrolysis products of this class of lipid are important in transmembrane signalling pathways.

The effects and interaction of the anatomical displacements in the human knee are a prerequisite to an accurate assessment and communication of the kinematic data. For the kinematic information to be used to improve diagnosis and treatment, and for better prosthetic design and installation, there must be clear, concise, and universal definitions of the displacements. In general, the displacements are defined as three translations and three rotations. In this paper, anatomic landmarks on the femur and on the tibia are used to define the locations and orientations of the six displacement axes; i.e. three translational and three rotational displacement axes. The most commonly accepted kinematic representation of the knee joint, in the literature, is a special geometry three-cylindric open chain in which the axes of the cylindric joints are defined according to the rotational displacement axes. The sequentially adjacent joint axes are assumed to not only intersect but to intersect at right-angles. The open chain permits a total of six degrees of freedom between a Cartesian reference frame attached to the femur and a Cartesian reference frame attached to the tibia. In this paper, the three rotational axes are shown to be skewed and off-set from each other, therefore, a three-cylindric open chain with skewed joint axes is proposed to measure the six displacements between the two reference frames. The authors believe that the proposed open chain is the most general to date and provides a more realistic representation of the displacements in the knee. To illustrate the significance of the reference frames on the interpretation of measured data, the anterior/posterior drawer is plotted against per cent gait cycle for three existing open chains and the proposed open chain.

Lactating Holstein cattle were treated twice at an interval of 14 days with methoxychlor (Marlate 50 insecticide) as a 0, .25, or .50% dermal spray, with 2 quarts of spray mix applied to each animal. Residues of methoxychlor in whole milk were highest on the 1st or 2nd day after treatment and, when expressed as part per million equivalent in milk fat, were as high as 2.0 and 3.0 ppm in samples from the low and high dosage sprays. Residues in milk dropped rapidly after residues were at most only slightly above the sensitivity limit (.005 ppm in whole milk) of the analytical method. Applicative specifications for Marlate 50 insecticide use on lactating dairy cattle might result in violative methoxychlor residues in milk during the first 1 to 3 days after treatment.

Human platelets contained proteins which cross-reacted with antisera specific for brain protein kinase C-alpha and -beta. When platelets were incubated with 12-O-tetradecanoylphorbol-13-acetate there was a rapid accumulation of protein kinase C-alpha in the particulate fraction associated with a loss of this subspecies from the soluble fraction. No particulate accumulation or soluble loss of protein kinase C-beta could be detected when platelets were incubated with the phorbol ester.