Borocaptate sodium: a potential boron delivery compound for boron neutron capture therapy evaluated in dogs with spontaneous intracranial tumors. Borocaptate sodium (Na2B12H11SH) is a boron-carrying compound under consideration for use in boron neutron capture therapy. The biodistribution of boron from borocaptate sodium administration will partly determine boron neutron capture therapy efficacy and normal tissue radiation tolerance. The biodistribution of boron was determined in 30 dogs with spontaneous intracranial tumors at 2, 6, or 12 hr after intravenous borocaptate sodium infusion. Blood and tissue boron concentrations were measured using inductively coupled plasma atomic emission spectroscopy. Mean tumor boron concentration (mean +/- standard error) was 35.9 +/- 4.6 (n = 15), 22.5 +/- 6.0 (n = 9), and 7.0 +/- 1.1 micrograms of boron per g (n = 6) at 2, 6, and 12 hr, respectively, after borocaptate sodium infusion. Peritumor boron concentrations were elevated above that of normal brain in half of the dogs. Normal brain boron concentration (mean +/- standard error) was 4.0 +/- 0.5, 2.0 +/- 0.4, and 2.0 +/- 0.3 micrograms of boron per g at 2, 6, and 12 hr after infusion, respectively. Some cranial and systemic tissues, and blood, had high boron concentration relative to tumor tissue. Geometric dose sparing should partly offset these relatively high normal tissue and blood concentrations. Borocaptate sodium biodistribution is favorable because tumor boron concentrations of recommended magnitude for boron neutron capture therapy were obtained and there was a high tumor-to-normal brain boron concentration ratio.


The alternative sigma factor katF (rpoS) regulates Salmonella virulence. Nutrient limitation is a critical signal in Salmonella virulence gene regulation. The katF (rpoS) gene mediates the expression of the Salmonella spv plasmid virulence genes during bacterial starvation. A katF Salmonella mutant has increased susceptibility to nutrient deprivation, oxidative stress, acid stress, and DNA damage, conditions which are relevant to the intraphagosomal environment of host macrophages. Moreover, the katF mutant has significantly reduced virulence in mice. katF encodes an alternative sigma factor of RNA polymerase which coordinately regulates Salmonella virulence.


Involvement of cytochrome P450 in host-plant utilization by Sonoran Desert Drosophila. The four Drosophila species endemic to the Sonoran Desert (Drosophila mettleri, Drosophila mojavensis, Drosophila nigrospiracula, and Drosophila pachea) utilize necrotic cactus tissue or soil soaked by rot exudate as breeding substrates. Each Drosophila species uses a different cactus species as its primary host. D. pachea is limited to senita cactus by a biochemical dependency on unusual sterols available only in that cactus. For the other Drosophila species, no such chemical dependencies exist to explain the relationships with their primary host plants. Each cactus species has a different array of allelochemicals that have detrimental effects on non-resident fly species. We have hypothesized that the desert fly-cactus associations are due, in part, to differences between the fly species in their allelochemical detoxication enzymes, the cytochrome P450 system. To test whether P450s are involved in the detoxication of cactus allelochemicals, several experiments were done. (i) The effect of a specific P450 inhibitor, piperonyl butoxide, on larval survival through eclosion on each cactus substrate was investigated. (ii) In vitro metabolism of cactus alkaloids was determined for each Drosophila species. The effects of specific inducers and inhibitors were included in these experiments. (iii) The basal and induced content of cytochrome P450 in each species was determined. The results support the hypothesis that P450 enzymes are involved in host-plant utilization by these Sonoran Desert Drosophila species.


High-level expression of a heterologous protein in the milk of transgenic swine using the cDNA encoding human protein C. Transgenic pigs were generated that produced human protein C in their milk at up to 1 g/liter. The gene construct was a fusion gene consisting of the cDNA for human protein C inserted into the first exon of the mouse whey acidic protein gene. These results demonstrate that the mouse whey acidic protein gene contains regulatory elements that can direct cDNA expression at high levels in the pig mammary gland. Recombinant human protein C that was produced at about 380 micrograms/ml per hr in transgenic pig milk possessed anticoagulant activity that was equivalent to that of protein C derived from human plasma. These studies provide evidence that gamma-carboxylation can occur at high levels in the mammary gland of a pig.


Human immunodeficiency virus gp120 binding C'C" ridge of CD4 domain 1 is also involved in interaction with class II major histocompatibility complex molecules. Using site-directed mutagenesis informed by high-resolution CD4 structural data, we have investigated the role of residues of the C'C'' ridge region of human CD4 on class II major histocompatibility complex (MHC) binding. This C'C'' ridge is homologous to the CDR2 loop of an immunoglobulin variable domain and is known to contain the binding site for human immunodeficiency virus (HIV) coat glycoprotein gp120. Here we report that this region is also involved in interaction with class II MHC. Exposed positively charged residues Lys-35, Lys-46, and Arg-59 and the exposed hydrophobic residue Phe-43 contribute significantly to class II MHC binding. Moreover, mutations in the buried residues Trp-62 and Ser-49, which support the top and bottom of the C'C'' ridge, respectively, disrupt class II MHC interaction. The HIV binding region appears to involve a restricted area of the larger class II MHC binding site on CD4. Strategies of drug design aimed at interrupting CD4-HIV interaction will need to consider the extensive overlap between class II MHC and HIV gp120 binding surfaces in this region of CD4.


Major histocompatibility complex class I-restricted T cells are required for resistance to Mycobacterium tuberculosis infection. Mice with a targeted disruption in the beta 2-microglobulin (beta 2m) gene, which lack major histocompatibility complex class I molecules and consequently fail to develop functional CD8 T cells, provided a useful model for assessing the role of class I-restricted T cells in resistance to infection with virulent Mycobacterium tuberculosis. Of mutant beta 2m-/-mice infected with virulent 10(6) M. tuberculosis, 70% were dead or moribund after 6 weeks, while all control mice expressing the beta 2m gene remained alive for > 20 weeks. Granuloma formation occurred in mutant and control mice, but far greater numbers of tubercle bacilli were present in the lungs of mutant mice than in controls, and caseating necrosis was seen only in beta 2m-/-lungs. In contrast, no differences were seen in the course of infection of mutant and control mice with an avirulent vaccine strain, bacille Calmette-Guérin (BCG). Immunization with BCG vaccine prolonged survival of beta 2m-/-mice after challenge with M. tuberculosis for 4 weeks but did not protect them from death. These data indicate that functional CD8 T cells, and possibly T cells bearing gamma delta antigen receptor, are a necessary component of a protective immune response to M. tuberculosis in mice.


Adhesion and incorporation of lacZ-transduced endothelial cells into the intact capillary wall in the rat. Use of the capillary bed of skeletal muscle as an in vivo recipient site to transplant autologous endothelial cells that have undergone gene transfer ex vivo has considerable potential as a technique of somatic gene therapy. Here we document a previously unrecognized capacity of endothelial cells to adhere and incorporate spontaneously into confluent endothelial cell monolayers in vitro and in vivo. This spontaneous adhesion and incorporation of endothelial cells enabled us to seed lacZ-transduced endothelial cells into the wall of skeletal muscle capillaries of the hindlimb of the rat. Certain transduced endothelial cells became incorporated within the capillary wall, whereas others remained within the capillary lumen where they formed focal, electron-dense, contacts with host endothelium. lacZ expression in the capillary bed was documented for up to 1 month after transplantation. Use of the intact capillary bed of skeletal muscle as an in vivo recipient site for transduced, autologous endothelial cells holds promise as a strategy for somatic gene therapy to treat various genetic and acquired human diseases.


Spectral enhancement of proteins: biological incorporation and fluorescence characterization of 5-hydroxytryptophan in bacteriophage lambda cI repressor. We have used a tryptophan-requiring Escherichia coli auxotroph to replace the three tryptophan residues of lambda cI repressor with 5-hydroxy-L-tryptophan (5-OHTrp). By using a nonleaky promoter, we have achieved > 95% replacement of tryptophan in the repressor. We show that the absorbance and fluorescence properties of 5-OHTrp-lambda cI are clearly distinct from lambda cI repressor and that the fluorescence of 5-OHTrp-lambda cI repressor can be observed selectively in the presence of exogenous tryptophan. We also show that the 5-OHTrp-lambda cI repressor functional properties, as assessed by measurement of binding constants for self-association and for association to operator DNA, and structural properties, as assessed by fluorescence, are indistinguishable from the native repressor. Based on these results, we anticipate that the availability of spectrally enhanced proteins will significantly enhance the utility of both fluorescence and phosphorescence spectroscopies to study protein structure and function in complex interacting systems.


Wild-type p53 binds to the TATA-binding protein and represses transcription. p53 activates transcription of genes with a p53 response element, and it can repress genes lacking the element. Here we demonstrate that wild-type but not mutant p53 inhibits transcription in a HeLa nuclear extract from minimal promoters. Wild-type but not mutant p53 binds to human TATA-binding protein (TBP). p53 does not bind to yeast TBP, and it cannot inhibit transcription in a HeLa extract where yeast TBP substitutes for human TBP. These results suggest a model in which p53 binds to TBP and interferes with transcriptional initiation.


Site-specific RNA cleavage generates the 3' end of a poxvirus late mRNA. The cowpox virus late mRNAs encoding the major protein of the A-type inclusions have 3' ends corresponding to a single site in the DNA template. The DNA sequence of the Alu I-Xba I fragment at this position encodes an RNA cis-acting signal, designated the AX element, which directs this RNA 3' end formation. In cells infected with vaccinia virus the AX element functions independently of either the nature of the promoter element or the RNA polymerase responsible for generating the primary RNA. At late times during virus replication, vaccinia virus induces or activates a site-specific endoribonuclease that cleaves primary RNAs within the AX element. The 3' end produced by RNA cleavage is then polyadenylylated to form the 3' end of the mature mRNA. Therefore, the poxviruses employ at least two mechanisms of RNA 3' end formation during the viral replication cycle. One mechanism, which is operative at early times in viral replication, involves the termination of transcription [Rohrmann, G., Yuen, L. & Moss, B. (1986) Cell 46, 1029-1035]. A second mechanism, which is operative at late times during viral replication, involves the site-specific cleavage of primary RNAs.


Expression of yeast hexokinase in pancreatic beta cells of transgenic mice reduces blood glucose, enhances insulin secretion, and decreases diabetes. It has been proposed that endogenous hexokinases of the pancreatic beta cell control the rate of glucose-stimulated insulin secretion and that genetic defects that reduce beta-cell hexokinase activity may lead to diabetes. To test these hypotheses, we have produced transgenic mice that have a 2-fold increase in hexokinase activity specific to the pancreatic beta cell. This increase was sufficient to significantly augment glucose-stimulated insulin secretion of isolated pancreatic islets, increase serum insulin levels in vivo, and lower the blood glucose levels of transgenic mice by 20-50% below control levels. Elevation of hexokinase activity also significantly reduced blood glucose levels of diabetic mice. These results confirm the role of beta-cell hexokinase activity in the regulation of insulin secretion and glucose homeostasis. They also provide strong support for the proposal that reductions in beta-cell hexokinase activity can produce diabetes.


Exogenous advanced glycosylation end products induce complex vascular dysfunction in normal animals: a model for diabetic and aging complications. Advanced glycosylation end products (AGEs) have been implicated in many of the complications of diabetes and normal aging. Markedly elevated vascular tissue and circulating AGEs were linked recently to the accelerated vasculopathy of end-stage diabetic renal disease. To determine the pathogenic role of AGEs in vivo, AGE-modified albumin was administered to healthy nondiabetic rats and rabbits alone or in combination with the AGE-crosslink inhibitor aminoguanidine. Within 2-4 weeks of AGE treatment, the AGE content of aortic tissue samples rose to six times the amount found in controls (P < 0.001). Cotreatment with aminoguanidine limited tissue AGE accumulation to levels two times that of control. AGE administration was associated with a significant increase in vascular permeability, as assessed by 125I label tracer methods. This alteration was absent in animals that received aminoguanidine in addition to AGE. Significant mononuclear cell migratory activity was observed in subendothelial and periarteriolar spaces in various tissues from AGE-treated rats compared to normal cellularity noted in tissues from animals treated with aminoguanidine. Blood pressure studies of AGE-treated rats and rabbits revealed markedly defective vasodilatory responses to acetylcholine and nitroglycerin compared to controls (P < 0.001), consistent with marked NO. inactivation; aminoguanidine treatment significantly prevented this defect. These in vivo data demonstrate directly that AGEs, independent of metabolic or genetic factors, can induce complex vascular alterations resembling those seen in diabetes or aging. AGE administration represents an animal model system for the study of diabetic and aging complications as well as for assessing the efficacy of newly emerging therapies aimed at inhibiting advanced glycosylation.


Distinct promoters direct neuronal and nonneuronal expression of rat aromatic L-amino acid decarboxylase. Aromatic L-amino acid decarboxylase (AADC, EC 4.1.1.28) catalyzes the decarboxylation of L-dopa to dopamine in catecholamine cells and 5-hydroxytryptophan to serotonin in serotonin-producing neurons. This enzyme is also expressed in relatively large quantities in nonneuronal tissues such as liver and kidney, where its function is unknown. Neuronal and nonneuronal tissues express AADC mRNAs with distinct 5' untranslated regions. To understand how this is accomplished at the genomic level, we have isolated rat genomic DNA encoding AADC. The organization of the AADC gene suggests that there are two separate promoters specific for the transcription of neuronal and nonneuronal forms of the AADC message. A small exon containing 68 bases of the neuronal-specific 5' end is located approximately 9.5 kilobases upstream of the translation start site, which is contained in the third exon. Approximately 7 kilobases upstream from the neuron-specific promoter is another small exon containing 71 bases of the 5' end of the nonneuronal AADC message. These data suggest that transcription initiating at distinct promoters, followed by alternative splicing, is responsible for the expression of the neuronal and nonneuronal forms of the AADC message.


Translocation of a folded protein across the outer membrane in Escherichia coli. A mutation in the Escherichia coli dsbA gene (coding for a periplasmic disulfide oxidoreductase) reduces the rate of disulfide bond formation in the enzyme pullulanase and also reduces the rate at which the enzyme is secreted to the cell surface, as measured by protease accessibility. The enzyme did not become protease accessible when disulfide bond formation was completely prevented in the mutant strain by carboxymethylation. These results indicate that a disulfide bond may be required for, and certainly does not impede, the translocation of pullulanase across the outer membrane. Since it is unlikely that a disulfide bond could be formed and then reduced again in the periplasm, these results would appear to strengthen the argument that pullulanase polypeptides fold into or close to their final conformation before they are transported across the outer membrane. It is suggested that this might be a feature common to all proteins that are secreted by other Gram-negative bacteria by a pullulanase-like pathway.


The Saccharomyces cerevisiae ARG4 initiator of meiotic gene conversion and its associated double-strand DNA breaks can be inhibited by transcriptional interference. In the yeast Saccharomyces cerevisiae, as in other eukaryotes, some regions of the genome have a much higher level of meiotic gene conversion than others. Previous deletion analysis indicated that the sequence necessary for the high level of gene conversion within the ARG4 region defined an initiation site located between positions -316 and -37 [relative to the first base pair (+1) of the ARG4 coding sequence] of the ARG4 promoter. To test whether this sequence is sufficient to promote gene conversion in a novel chromosomal context, we inverted on the chromosome various DNA fragments including the implicated region and the ARG4 coding sequence. Surprisingly, these inversions resulted in the loss of the normal recombination properties and double-strand-break formation associated with this process. By Northern analysis, we found that a transcript traverses the ARG4 initiation site in these inversion mutants but not in the wild type. When transcription through this region was prevented by a transcription terminator, the activity of the initiation site and the formation of double-strand breaks were restored. From these results and from complementary deletion analysis in the normal ARG4 orientation, we conclude that the activity of the ARG4 initiation site requires protection from transcriptional interference.


Chi sequence protects against RecBCD degradation of DNA in vivo. RecBCD is a multifunctional enzyme involved in DNA degradation and homologous recombination. It also produces an endonucleolytic cleavage near properly oriented chi sites (5'-GCTGGTGG-3'). Plasmids are not known to be affected by either RecBCD enzyme or the presence of a chi site. We report here that plasmids that replicate by a rolling circle mechanism accumulate large amounts of high molecular weight linear multimers (HMW), either if they contain a chi site or if RecBCD is absent. An in vivo inducible system for rolling circle replication was constructed to study RecBCD and its interactions with chi. Results show that (i) HMW accumulation is chi orientation dependent, and (ii) a succession of chi sites prevents degradation of HMW by RecBCD enzyme. These results demonstrate chi activity in plasmids. The rolling circle mechanism produces a sigma structure during plasmid replication; we propose that the double-stranded DNA tail of this sigma form allows RecBCD entry; the tail is degraded unless it is protected by a chi site. By analogy, a principal role of chi in the survival of lambda red-gam- mutants in wild-type strains may be to protect rolling circle concatemers (in late replication) from degradation by RecBCD.


Organization of the human skeletal myosin heavy chain gene cluster. Myosin is an important structural and enzymatic component of skeletal muscle. Multiple myosin isoforms are encoded by a multigene family and are expressed in different developmental stages and fiber types. In humans and mice, skeletal myosin heavy chain (MYH) genes are clustered on a single chromosome (17p and 11, respectively). Since the structural organization of the gene cluster may affect its expression as well as shed light on MYH genetic alterations, a physical map of the human MYH gene cluster was constructed. Nine yeast artificial chromosomes containing MYH genes were isolated and used to construct a contiguous set (contig) of overlapping yeast artificial chromosomes. This contig encompasses a genetic marker mapped to 17p13.1. Six MYH genes were located within a 500-kilobase segment of human DNA. The order of the genes within this cluster does not correspond to the developmental pattern of expression of individual members.


Interleukin 7 receptor functions by recruiting the tyrosine kinase p59fyn through a segment of its cytoplasmic tail. Engagement of the cell surface receptor for interleukin 7 (IL-7R) provokes protein tyrosine phosphorylation, although the receptor lacks a kinase catalytic domain in its cytoplasmic tail. The molecular basis of this response is not known. Here we report that the IL-7R functions by recruiting p59fyn, an intracellular tyrosine kinase of the src family. Treatment of pre-B cells with IL-7 causes an enhancement of the catalytic activity of p59fyn, but not of the related kinase p62yes. IL-7-dependent stimulation of the enzyme phosphatidylinositol 3-kinase, a tyrosine kinase substrate, provides further evidence suggestive of p59fyn activation. We demonstrate that p59fyn forms part of a protein complex with the IL-7R. A chimeric receptor comprising the CD8 extracellular domain and the IL-7R cytoplasmic tail (CD8/IL-7R) recruits tyrosine kinase activity in transfected myeloma cells, and p59fyn can be detected in association with it by immunoprecipitation and immunoblotting. Conversely, p59fyn immunoprecipitates contain the phosphorylated CD8/IL-7R. We have identified a segment of the IL-7R cytoplasmic tail which mediates p59fyn recruitment: a truncated CD8/IL-7R containing only this segment recruits tyrosine kinase activity, associates with p59fyn, and activates phosphatidylinositol 3-kinase. Interestingly, this segment contains no tyrosine residues, although it is the phosphotyrosine-binding src homology domains of p59fyn and phosphatidylinositol 3-kinase which mediate their association with many growth factor receptors. Thus our results suggest that an unusual interaction links IL-7R to these two important signaling pathways.


Sequence-structure matching in globular proteins: application to supersecondary and tertiary structure determination. A methodology designed to address the inverse globular protein-folding problem (the identification of which sequences are compatible with a given three-dimensional structure) is described. By using a library of protein finger-prints, defined by the side chain interaction pattern, it is possible to match each structure to its own sequence in an exhaustive data base search. It is shown that this is a permissive requirement for the validation of the methodology. To pass the more rigorous test of identifying proteins that are not close sequence homologs, but that have similar structure, the method has been extended to include insertions and deletions in the sequence, which is compared to the fingerprint. This allows for the identification of sequences having little or no sequence homology to the fingerprint. Examples include plastocyanin/azurin/pseudoazurin, the globin family, different families of proteases and cytochromes, including cytochromes c' and b-562, actinidin/papain, and lysozyme/alpha-lactalbumin. Turning to supersecondary structure prediction, we find that alpha/beta/alpha fragments possess sufficient specificity to identify their own and related sequences. By threading a beta-hairpin through a sequence, it is possible to predict the location of such hairpins and turns with remarkable fidelity. Thus, the method greatly extends existing techniques for the prediction of both global structural homology and local supersecondary structure.


Patterns of spatiotemporal organization in an "ambiquitous" enzyme model. Many enzymes in pathways such as glycolysis associate reversibly with cellular substructures. The spatiotemporal behavior of a "limit-cycle" oscillation model is studied under the condition that the "ambiquitous" oscillophor, phosphofructokinase, is partitioned between "bulk-phase" and "bound" forms in a heterogeneous system. Computer simulation demonstrates the occurrence of sustained, wave-like spatiotemporal patterns of chemical concentration in the bulk medium. Kinetic dissimilarity among the localized populations of bound enzyme leads to a "polarity" effect in the wave phenomenon. It is suggested that a key physiological role of the limit-cycle regime is to engender a rapid, site-to-site, signal-transmission modality in large eukaryotic (e.g., mammalian) cells.


Repair of DNA damaged by UV light and ionizing radiation by cell-free extracts prepared from Schizosaccharomyces pombe. A whole cell extract prepared from Schizosaccharomyces pombe was shown to be active in an assay for repair of plasmid DNA damaged by either ultraviolet (UV) light or gamma-radiation. The assay allows for analysis of repair synthesis at single-strand nicks generated by gamma-rays and analysis of the incision step and repair synthesis in UV-light-damaged DNA. Repair synthesis of DNA damaged by either UV light or gamma-rays was shown to depend on the presence of ATP in the reaction mixture. However, incision at pyrimidine dimers did not require the addition of exogenous ATP. These studies showed that plasmid DNA containing a single pyrimidine dimer or one single-strand nick is a suitable substrate in this assay system. S. pombe is a genetically well-defined eukaryotic organism and many radiation-sensitive mutant derivatives have already been described, making this a powerful system in which to study DNA excision repair.


Empty and peptide-containing conformers of class I major histocompatibility complex molecules expressed in Drosophila melanogaster cells. Transfected Drosophila melanogaster cells can express large quantities of class I major histocompatibility complex molecules. Such molecules lack endogenous peptides because the Drosophila cells are devoid of proteins necessary for intracellular peptide loading. The empty molecules are efficiently expressed on the cell surface and can acquire extracellular peptides. The conformation and stability of empty murine class I molecules are determined by the source of beta 2-microglobulin. All beta 2-microglobulin-induced conformers of empty heavy chains seem to be unified in a common rigid conformation on peptide binding.


Genomic structure of the human caldesmon gene. The high molecular weight caldesmon (h-CaD) is predominantly expressed in smooth muscles, whereas the low molecular weight caldesmon (l-CaD) is widely distributed in nonmuscle tissues and cells. The changes in CaD isoform expression are closely correlated with the phenotypic modulation of smooth muscle cells. During a search for isoform diversity of human CaDs, l-CaD cDNAs were cloned from HeLa S3 cells. HeLa l-CaD I is composed of 558 amino acids, whereas 26 amino acids (residues 202-227 for HeLa l-CaD I) are deleted in HeLa l-CaD II. The short amino-terminal sequence of HeLa l-CaDs is different from that of fibroblast (WI-38) l-CaD II and human aorta h-CaD. We have also identified WI-38 l-CaD I, which contains a 26-amino acid insertion relative to WI-38 l-CaD II. To reveal the molecular events of the expressional regulation of the CaD isoforms, the genomic structure of the human CaD gene was determined. The human CaD gene is composed of 14 exons and was mapped to a single locus, 7q33-q34. The 26-amino acid insertion is encoded in exon 4 and is specifically spliced in the mRNAs for both h-CaD and l-CaDs I. Exon 3 is the exon that encodes the central repeating domain specific to h-CaD (residues 208-436) together with the common domain in all CaD (residues 73-207 for h-CaD and WI-38 l-CaDs, and residues 68-201 for HeLa l-CaDs). The regulation of h- and l-CaD expression is thought to depend on selection of the two 5' splice sites within exon 3. Thus, the change in expression between l-CaD and h-CaD might be caused by this splicing pathway.


Helix-loop-helix transcription factors E12 and E47 are not essential for skeletal or cardiac myogenesis, erythropoiesis, chondrogenesis, or neurogenesis. E12 and E47 are two non-tissue-specific helix-loop-helix (HLH) transcription factors encoded by the E2A gene. Previous studies suggested that they are involved in regulation of differentiation in many tissue types including muscle, blood, and nerve through direct heterodimer interactions with tissue-specific HLH proteins. To gain further genetic insight into the functions of E12 and E47 during cell differentiation, we mutated both copies of the E2A gene in mouse embryonic stem (ES) cells and then tested the effect on differentiation in vitro. We find that the ES cells lacking functional E12 and E47 are capable of differentiating into both skeletal and cardiac muscle, erythrocytes, neurons, and cartilage that the same extent as wild-type cells. These results indicate that the E2A gene is not essential for differentiation of these cell types and suggest that redundant genes may control these developmental pathways.


Costs of deception: cheaters are punished in rhesus monkeys (Macaca mulatta). From a functional perspective, deception can evolve in animal populations but should be constrained by the costs associated with detection. It then follows that withholding information should be more prevalent as a form of deception than active falsification of information because of the relative difficulties associated with detecting cheaters. Empirical studies of deception have focused on the benefits of cheating but have provided no data on the costs associated with being detected as a cheater. I present results from field experiments on rhesus monkeys (Macaca mulatta) which show that individuals discovering food announce their discoveries by calling on 45% of all trials. Discoverers who failed to call, but were detected with food by other group members, received significantly more aggression than vocal discoverers. Moreover, silent female discoverers ate significantly less food than vocal females. This demonstrates that there are significant costs to withholding information. Such costs may constrain the frequency with which deception occurs in this and other populations.


Intermolecular interactions between the A and B subunits of heat-labile enterotoxin from Escherichia coli promote holotoxin assembly and stability in vivo. Cholera toxin and the related heat-labile enterotoxin (LT) produced by Escherichia coli consist of a holotoxin of one A subunit and five B subunits (AB5). Here we investigate the domains of the A subunit (EtxA) of E. coli LT which influence the events of B-subunit (EtxB) oligomerization and the formation of a stable AB5 holotoxin complex. We show that the C-terminal 14 amino acids of the A subunit comprise two functional domains that differentially affect oligomerization and holotoxin stability. Deletion of the last 14 amino acids (-14) from the A subunit resulted in a molecule that was significantly impaired in its capacity to promote the assembly of a mutant B subunit, EtxB191.5. In contrast, deletion of the last four amino acids (-4) from the A subunit gave a molecule that retained such a capacity. This suggests that C-terminal residues within the -14 to -4 region of the A subunit are important for promoting the oligomerization of EtxB. In addition, we demonstrate that the truncated A subunit lacking the last 4 amino acids was unable to form a stable AB5 holotoxin complex even though it promoted B-subunit oligomerization. This suggests that the last 4 residues of the A subunit function as an "anchoring" sequence responsible for maintaining the stability of A/B subunit interaction during holotoxin assembly. These data represent an important example of how intermolecular interactions between polypeptides in vivo can modulate the folding and assembly of a macromolecular complex.


Cloning and expression of a cDNA encoding the transporter of taurine and beta-alanine in mouse brain. A taurine/beta-alanine transporter was cloned from a mouse brain cDNA library by screening with a partial cDNA probe of the glycine transporter at low stringency. The deduced amino acid sequence predicts 590 amino acids with typical characteristics of the sodium-dependent neurotransmitter transporters such as sequence homology and membrane topography. However, the calculated isoelectric point of the taurine/beta-alanine transporter is more acidic (pI = 5.98) than those (pI > 8.0) of other cloned neurotransmitter transporters. Xenopus oocytes injected with cRNA of the cloned transporter expressed uptake activities with Km = 4.5 microM for taurine and Km = 56 microM for beta-alanine. Northern hybridization showed a single transcript of 7.5 kilobases that was highly enriched in kidney and distributed evenly in various parts of the brain. In situ hybridization showed the mRNA of the taurine/beta-alanine transporter to be localized in the corpus callosum, striatum, and anterior commisure. Specific localization of the taurine/beta-alanine transporter in mouse brain suggests a potential function for taurine and beta-alanine as neurotransmitters.


High expression of human beta S- and alpha-globins in transgenic mice: hemoglobin composition and hematological consequences. A line of transgenic mice (alpha H beta S-11; where alpha H is human alpha-globin) was created in which the human beta S and human alpha 2 globin genes, each linked to the beta-globin locus control region, were cointegrated into the mouse genome. On a normal genetic background, the transgenic mice produced 36% human beta S-globin chains with an alpha H/beta S ratio of 1.3. Higher levels of beta S were achieved by breeding the transgenic mice with mutant mice carrying a mouse beta major-globin gene deletion. Mice heterozygous for the beta major deletion (alpha H beta S[beta MD]; MD, mouse deletion) had 54% beta S with an alpha H/beta S ratio of 1.0; mice homozygous for the beta major deletion (alpha H beta S[beta MDD]) had 72.5% beta S and an alpha H/beta S ratio of 0.73. Because mouse alpha chains inhibit hemoglobin (Hb) S polymerization, we bred the mice to heterozygosity for a mouse alpha-globin deletion. These mice (alpha H beta S[alpha MD beta MDD]) had an increased alpha H/beta S ratio of 0.89 but expressed 65% beta S. Expression of the human genes cured the thalassemic phenotype associated with the murine beta major deletion. Transgenic alpha H beta S[beta MDD] mice had normal hematocrit and Hb and somewhat elevated reticulocytes (6% vs. 3% for control), whereas the mice carrying the alpha-globin deletion (alpha H beta S[alpha MD beta MDD]) had a normal hematocrit and Hb and more elevated reticulocytes (10.3 +/- 7.6% vs. 3.4 +/- 1.0%). Expression of the transgene restored a normal distribution of erythrocyte densities when compared to thalassemic mice; however, the average mean corpuscular Hb concentration of alpha H beta S[beta MDD] mice increased to 35.7 g/dl (vs. control 33.7 g/dl) whereas that of alpha H beta S[alpha MD beta MDD] mice was further elevated to 36.3 g/dl. The intrinsic oxygen affinity was increased in transgenic mouse erythrocytes at 280 milliosmolal, and the PO2 at midsaturation of alpha H beta S[alpha MD beta MDD] erythrocytes was higher than that of alpha H beta S[beta MDD] cells (37.4 +/- 2 vs. 33.5 +/- 1 mmHg). The higher values of the mean corpuscular Hb concentration and intrinsic PO2 at midsaturation, which favor in vivo sickling, may explain the slightly more severe hematological picture in alpha H beta S[alpha MD beta MDD] mice. We conclude that the transgenic mouse with high Hb S expression does not exhibit adult anemia but does have abnormal hematological features: increased erythrocyte density, high oxygen affinity, and reticulocytosis with increased stress reticulocytes.


High expression of human beta S- and alpha-globins in transgenic mice: erythrocyte abnormalities, organ damage, and the effect of hypoxia. A line of transgenic mice with two cointegrated transgenes, the human beta S- and alpha 2-globin genes, linked to the beta-globin locus control region was produced and bred with mice carrying a deletion of the mouse beta major-globin gene. In transgenic mice homozygous for the beta major deletion (alpha H beta S[beta MDD]; where alpha H is human alpha-globin and MD is mouse deletion), 72.5 +/- 2.4% (mean +/- SD) of the beta-chains are beta S and the ratio of alpha H- to beta S-globin was 0.73. Introduction of a heterozygous mouse alpha-globin deletion into mice homozygous for the beta major deletion (alpha H beta S[alpha MD beta MDD]) resulted in 65.1 +/- 8.5% beta S and a human alpha/beta ratio of 0.89 +/- 0.2. Sickling occurs in 95% of erythrocytes from alpha H beta S[beta MDD] mice after slow deoxygenation. Transmission electron microscopy revealed polymer fiber formation but not fascicles of fiber. Increased organ weight was noted in lung, spleen, and kidney of transgenic mice vs. controls that may be due to hypertrophy or increased blood volume in the lungs and/or increased tissue water content. The hemoglobin content of lung, spleen, and kidney was also elevated in transgenic animals due to trapped hemoglobin and/or increased blood volume. When transgenic and control mice were examined by magnetic resonance imaging at 9.4 tesla, some transgenic animals had enlarged kidneys with prolonged relaxation time, consistent with increased organ weight and water content. The glomerular filtration rate was elevated in transgenic animals, which is characteristic of young sickle cell patients. Furthermore, exposure to hypoxia resulted in significantly decreased hematocrit, increased erythrocyte density, and induced a urine-concentrating defect. We conclude that the transgenic mouse line reported here has chronic organ damage and further hematological and organ dysfunction can be induced by hypoxia.


Genomic structure of DNA encoding the lymphocyte homing receptor CD44 reveals at least 12 alternatively spliced exons. The CD44 molecule is known to display extensive size heterogeneity, which has been attributed both to alternative splicing and to differential glycosylation within the extracellular domain. Although the presence of several alternative exons has been partly inferred from cDNA sequencing, the precise intron-exon organization of the CD44 gene has not been described to date to our knowledge. In the present study we describe the structure of the human CD44 gene, which contains at least 19 exons spanning some 50 kilobases of DNA. We have identified 10 alternatively spliced exons within the extracellular domain, including 1 exon that has not been previously reported. In addition to the inclusion or exclusion of whole exons, more diversity is generated through the utilization of internal splice donor and acceptor sites within 2 of the individual exons. The variation previously reported for the cytoplasmic domain is shown to result from the alternative splicing of 2 exons. The genomic structure of CD44 reveals a remarkable degree of complexity, and we confirm the role of alternative splicing as the basis of the structural and functional diversity seen in the CD44 molecule.


Correlation analysis of amino acid usage in protein classes. We present a comparative study of residue usage correlations of various organism protein sets of diverse phylogenetic species and of open reading frames of several large human viral genomes. Our correlation analysis reveals three major tendencies: (i) charge compensation reflected by the high correlation of basic with acidic residues; (ii) the positive correlations of functionally and structurally similar amino acids including many pairs of hydrophobic amino acids, all pairs of aromatic amino acids, the anionic pair (glutamate and aspartate), but not the cationic pair (lysine and arginine), moderately the hydroxyl pair (serine and threonine), the small amino acids (glycine and alanine), and many (but not all) of those having high values in the Dayhoff substitutability matrix (characteristics such as amino acid polarity or codon usage agreement, except for the wobble position, do not necessarily imply significant positive correlations); (iii) a widespread negative correlation of the aggregate strong codon group amino acids (Ala, Gly, Pro) versus the weak codon group amino acids (Lys, Ile, Tyr, Asn, Phe). Discussion and speculations relate amino acid usage correlations to protein function/structure, cellular localization, proximity in amino acid biosynthetic pathways, amino acid relative abundances, tRNA and aminoacyl synthetase availabilities, and evolutionary processes.


Ovariectomy selectively reduces the concentration of transforming growth factor beta in rat bone: implications for estrogen deficiency-associated bone loss. Previous work showed that production of transforming growth factor beta (TGF-beta) by osteoblast-like rat UMR 106 cells was increased by 17 beta-estradiol at physiological concentrations. To determine whether ovariectomy alters the concentration of TGF-beta in rat long bones, female Sprague-Dawley rats were either sham-operated (n = 19) or ovariectomized (n = 19), pair-fed a semisynthetic diet for 6 weeks, and sacrificed. Tibial and femoral diaphyses were removed and extracted by demineralization. Ovariectomy lowered serum estrogen; did not alter body weight, serum magnesium, or serum 1,25-dihydroxyvitamin D; and produced only modest differences in serum calcium and phosphate concentrations. Hydroxyproline was higher and extractable protein was lower in bones from ovariectomized rats than in bones from sham-operated rats; calcium content did not differ between the two groups of animals. Ovariectomy lowered the concentration of TGF-beta in bone but did not change the concentration of insulin-like growth factors I or II compared with values in bone from control animals. The reduction of bone TGF-beta was evident 6 weeks after surgery but not at 3 weeks. Treatment of ovariectomized rats with estrogen eliminated the TGF-beta deficit. To determine whether 17 beta-estradiol increased TGF-beta production by normal bone cells, mouse osteoblasts were treated for 2 days with 17 beta-estradiol. The production of TGF-beta was increased almost 2-fold by 1 nM 17 beta-estradiol, and short-term treatment stimulated the intracellular accumulation of TGF-beta 1 mRNA. We conclude that ovariectomy reduces deposition of TGF-beta in rat bone and that diminished skeletal TGF-beta could play a role in the pathogenesis of bone loss, fractures, and microfractures that occur in estrogen-deficient states. Our results support the possibility that estrogen and bone TGF-beta may be necessary for normal maintenance of the skeleton in female rats.


Approach to a retrovirus vaccine: immunization of mice against Friend virus disease with a replication-defective Friend murine leukemia virus. In an initial attempt to test the ability of replication-defective retroviruses to immunize against immunologically related pathogenic viruses, we have worked with the erythroleukemogenic Friend retrovirus complex (FV), which consists of a replication-competent helper component, Friend murine leukemia virus (FMuLV), and a related defective pathogenic component, spleen focus-forming virus (SFFV). An 81-base-pair deletion was introduced into the p15E-encoding region of the env gene of an otherwise replication-competent molecular clone of the FMuLV provirus. After transfection of this clone into cells that package the viral RNA in MuLV coats, infectious virus was released into the culture medium. Mouse fibroblasts infected with this virus, here called delta FMuLV, expressed the truncated viral env gene products in their cytoplasm but not on cell surfaces, and culture fluids from these cells did not transmit the infection to fresh mouse fibroblasts. In preliminary experiments, immunization of mice of H-2-congenic BALB/c strains with delta FMuLV conferred levels of immunity to FV disease ranging from weak to relatively strong. Immunized mice developed anti-FV IgM and IgG antibodies and cytotoxic T cells. Mice observed for 15 weeks after the first of two immunizations showed no detectable pathology, but delta FMuLV DNA was detectable in livers of some immunized mice for at least 3-6 weeks. These results suggest that our approach to development of retrovirus vaccines may be a useful one.


An opportunist to keep at bay. Pseudomonas in ITU. Pseudomonas is a common cause of infection in ITU. To minimise incidence of this opportunistic infection, it is essential that nursing care is based on research, rather than ritual.


Lasting relief from a distressing condition. Surgical intervention in hidradenitis suppurativa. Hidradenitis suppurativa is a painful skin condition which affects the skin glands. The condition can be successfully treated with surgery, but requires skillful and sensitive pre- and post-operative nursing care.


A strategy to regain control: helplessness and depressive illness in women. The feelings of helplessness which accompany depression in many women have known psychological, physiological and sociological causes. By including patients in the decision-making process, nurses can help them begin to take control over their lives.


How much do they know? A study into patients' knowledge of drugs. If patients are to make informed decisions about the treatment they receive, they need adequate information about their treatment. This study looks at renal patients' knowledge of the drugs they are prescribed to manage their condition.


An adequate recourse to protection? Using a multidisciplinary approach to resolve elderly abuse. Abuse of elderly, dependent people by their carers is a problem that many in the legal and healthcare professions would prefer to ignore. It is essential, however, that this problem is highlighted and cases are referred to a multidisciplinary case conference so the individual's protection and security can be assured.


How much should we tell them? Patient education for people with diabetes. Patient education assumes that by giving people with diabetes information about their condition, they will take steps to prevent potential complications. Not all clients, however, are willing to follow advice or are prepared to make short-term sacrifices for long-term gains. Informing clients about the potential for complications, however, enables them to share responsibility for the outcome.


A challenge we can all achieve. Total quality management in healthcare. The healthcare system is becoming increasingly concerned with initiatives to ensure and improve the quality of its services. Quality assurance, prevalent in much of nursing, can be overly bureaucratic; total quality management focuses the entire organisation on achieving quality.


Early removal advances discharge home. Comparison of midnight and early morning catheter removal following prostatectomy. Resumption of normal voiding is necessary before prostatectomy patients can be discharged from hospital. This study assesses the effect upon this of the timing of catheter removal.


A seasonal depression. Management of seasonal affective disorder. 1. SAD is a mood disorder characterised by recurring cyclic periods of autumn/winter dysthymia alternating with late spring/summer euthymia or hypomania. 2. It is now thought that SAD sufferers may be deficient in certain brain chemicals, and it is likely that the interactions of a number of neurotransmitters are responsible for the disorder. 3. In the UK, 72% of SAD sufferers report an increase in sleep from around seven hours in the summer to nine in winter. 4. Phototherapy has been proved an effective treatment for SAD, and lamps for phototherapy are becoming increasingly available.


Correlations of purinergic, cholinergic and adrenergic functions in rabbit corporal cavernosal tissue. Erection involves cholinergic, adrenergic as well as non-cholinergic non-adrenergic nerves. Endothelial-derived relaxation factor plays an important role in mediating smooth muscle relaxation, which is crucial in initiating and maintaining erection. We previously showed that adenosine 5'-triphosphate (ATP) can induce significant relaxation in rabbit corporal cavernosal tissue. The present study presents effects of different neurotransmitters and the role of endothelium in controlling the contractile/relaxant status of rabbit cavernosal tissue. These studies utilized isolated tissue strips prepared from the corpus cavernosum of sexually mature male New Zealand white rabbits. The results can be summarized as follows: (1) field stimulation caused relaxations with rebound contractions in most strips; (2) bethanechol (250 microM), isoproterenol (20 microM) and ATP (1 mM) all induced relaxations, though the relaxation induced by bethanechol was poorly sustained; (3) removal of the endothelium by rubbing decreased the relaxation to field stimulation and virtually eliminated the relaxation induced by bethanechol, but had no effect on the relaxation responses to isoproterenol and ATP; (4) methoxamine (200 microM) stimulated a sustained contraction of corporal cavernosal tissue, an effect unaltered by rubbing the strips; (5) low dose epinephrine induced relaxation, whereas higher concentrations contracted the tissue, and (6) beta-adrenergic inhibition with propranolol (20 microM) was significantly more effective than mascarinic blockade with atropine (20 microM) in eliminating relaxation caused by field stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)


Effect of the potassium channel opener EMD 56431 on globally ischemic rat hearts. The effect of the ATP-sensitive potassium channel opener EMD 56431 on coronary vasodilation and cardioprotection in isolated rat hearts was investigated. EMD 56431 caused a significant increase in pre-ischemic coronary flow. Time to contracture and reperfusion function were significantly increased at 3, 10 and 30 microM concentrations. LDH release was significantly reduced at 10 and 30 microM concentrations. 1 microM glyburide completely abolished the protective effects found with 10 microM EMD 56431. When given during reperfusion only, 10 microM EMD 56431 showed no cardioprotection. Thus, EMD 56431 appeared to reduce the severity of ischemia/reperfusion injury. The vasorelaxant versus cardioprotective effects for EMD 56431 are similar to other potassium channel openers, such as cromakalim.


Carbonic anhydrase inhibition by flurbiprofen and related agents. Flurbiprofen, a nonsteroidal anti-inflammatory drug (NSAID), reduces bone resorption in periodontal disease. This therapeutic effect has been attributed to inhibition of prostaglandin synthesis. In view of the importance of carbonic anhydrase (CA) in bone resorption, we examined the CA-inhibitory properties of flurbiprofen using bovine and human CA II and compared them with those of acetazolamide and two other NSAIDs, ibuprofen and indomethacin. Flurbiprofen inhibited both human and bovine erythrocyte CA II but to a much lesser degree than acetazolamide. Ibuprofen and indomethacin were much less active in inhibiting CA II than flurbiprofen.


Comparison of sorbinil and ponalrestat (Statil) diminution of proteinuria in the BB rat. Diabetic nephropathy leading to kidney failure is a major complication of type I (insulin-dependent) diabetes mellitus and is associated with progressive proteinuria. In the present 6-month study, effects of two structurally dissimilar aldose reductase inhibitors (sorbinil and ponalrestat or Statil) were examined on prevention of proteinuria in insulin-dependent spontaneously diabetic BB rats and compared with age-matched BB resistant controls. Prior to aldose reductase inhibitor treatment, all diabetic BB rats exhibited hyperglycemia (> 300 mg/dl), glycosuria (> 2,000 mg/dl) and 24-hour urinary protein excretion ranging from 5.01 to 11.23 mg/day. After daily administration of ponalrestat (20 mg/kg) for 3 months, 24-hour urinary protein excretion was 11.53 +/- 1.76 mg/day in ponalrestat-treated rats, despite persistence of hyperglycemia (444 +/- 31 mg/dl) and glycosuria (> 2,000 mg/dl); by contrast, urinary protein excretion was 17.76 +/- 2.59 mg/day in the control group of untreated BB diabetic rats. Ponalrestat initially protected against excretion of an array of urinary proteins having molecular weights between 30,000 and 100,000 daltons. These effects sustained throughout the 4th month of treatment, tended to change toward valves in control rats by the 5th month. At the end of 6 months, ponalrestat-treated diabetic rats excreted 18.73 +/- 3.20 mg/day of protein, similar to valves in untreated BB diabetic rats; both demonstrated a 4-fold increase in urinary protein excretion when compared to age-matched BB resistant controls. Proteinuria was attributed to an increase in albumin and an array of proteins having molecular weights between 30,000 and 100,000 daltons.(ABSTRACT TRUNCATED AT 250 WORDS)


Inhibitory effect of beta-alanyl-L-histidinato zinc on bone resorption in tissue culture. The inhibitory effect of beta-alanyl-L-histidinato zinc (AHZ) on bone resorption in tissue culture was investigated. Calvaria were removed from weanling rats (3-week-old male) and cultured for periods up to 48 h in Dulbecco's modified Eagle medium (high glucose, 4.5%) supplemented with antibiotics and bovine serum albumin. The experimental cultures contained 10(-7) to 10(-4) mol/l AHZ. The bone-resorbing factors, parathyroid hormone (1-34) (PTH; 10(-7) mol/l), prostaglandin E2 (10(-5) mol/l), interleukin-1 alpha (IL1 alpha; 50 U/ml), and lipopolysaccharide (10 micrograms/ml), caused a significant decrease in bone calcium content. The decreases in bone calcium content induced by bone-resorbing factors were completely inhibited by the coexistence of AHZ (10(-6) to 10(-4) mol/l). Also, AHZ (10(-5) mol/l) completely inhibited the PTH (10(-7) mol/l) or IL1 alpha (50 U/ml)-induced increase in medium glucose consumption and lactic acid production by bone tissue. Furthermore, AHZ (10(-5) mol/l) fairly blocked both PTH (10(-7) mol/l)-increased acid phosphatase and decreased alkaline phosphatase activities of bone tissue. The inhibitory effect of AHZ (10(-5) mol/l) on PTH (10(-7) mol/l)-stimulated bone resorption was clearly prevented by the presence of 10(-4) mol/l dipicolinate, a chelator of zinc. However, zinc sulfate (10(-7) to 10(-4) mol/l) did not inhibit the PTH (10(-7) mol/l)-stimulated bone resorption in tissue culture. These findings indicate that AHZ had a direct inhibitory effect on bone resorption in vitro, and the AHZ effect was found in the chemical form of zinc-chelated dipeptide.


Methylated cap structures in eukaryotic RNAs: structure, synthesis and functions. There are more than twenty capped small nuclear RNAs characterized in eukaryotic cells. All the capped RNAs appear to be involved in the processing of other nuclear premessenger or preribosomal RNAs. These RNAs contain either trimethylguanosine (TMG) cap structure or methylated gamma phosphate (Mppp) cap structure. The TMG capped RNAs are capped with M7G during transcription by RNA polymerase II and trimethylated further post-transcriptionally. The Mppp-capped RNAs are transcribed by RNA polymerase III and also capped post-transcriptionally. The cap structures improve the stability of the RNAs and in some cases TMG cap is required for transport of the ribonucleoproteins from cytoplasm to the nucleus. Where tested, the cap structures were not essential for their function in processing other RNAs.


Membrane structure, toxins and phospholipase A2 activity. The phospholipid-hydrolyzing enzyme phospholipase A2 (PLA2) (EC 3.1.1.4) exists in several forms which can be located in the cytosol or on cellular membranes. We review briefly cellular regulatory mechanisms involving covalent modification by protein kinase C and the action of Ca2+, cytokines, G proteins and other cellular proteins. The major focus is the role of phospholipid structure on PLA2 activity, including (1) the mechanism of PLA2 action on synthetic phospholipid bilayers, (2) perturbation of synthetic and cellular membranes with lipophilic agents and membrane-interactive peptides and (3) the ability of these agents to activate endogenous PLA2 activity, with emphasis on the venom and plant toxins melittin, cardiotoxin and Pyrularia thionein.


Rational use of antiepileptic drug levels. Antiepileptic drug (AED) levels are obtained frequently in clinical practice, but their complex relation to seizures or drug toxicity often makes interpretation of the results difficult. Research studies have not always taken into account clinical, as well as pharmacokinetic and pharmacodynamic, factors which may influence the drug level-effect relationship. AED levels should be drawn at an appropriate time in relation to drug ingestion and clinical symptoms. Systematic investigations in selected patients, during which several levels are obtained, may be more rewarding than routine measurements in a large clinic population.


Role of the RNA-dependent protein kinase in the regulated expression of genes in transfected cells. The RNA-dependent P1/eIF-2 alpha protein kinase is a highly specific protein-serine/threonine kinase that catalyzes the phosphorylation of the alpha subunit of protein synthesis initiation factor eIF-2. The kinase plays a central role in translational control. The activity of the kinase is regulated by a variety of naturally occurring effector RNAs which bind to the regulatory domain of the enzyme. Certain RNAs are able to activate the eIF-2 alpha kinase activity inherent within protein P1, a process which involves an autophosphorylation of protein P1, whereas other RNAs are able to antagonize the activation process. Translational repression mediated by the kinase may also be disrupted by RNA binding proteins that sequester activator double-stranded RNAs and by site-directed mutants and homologs of the eIF-2 alpha translation factor substrate. The P1/eIF-2 alpha protein kinase is an important regulator of the translation of plasmid-derived mRNAs in transfected eukaryotic cells.


The disclosure of the diagnosis of cancer. In summary, the consensus today is that full disclosure of the diagnosis of cancer to competent individuals (including children) is morally, ethically, legally, and therapeutically the appropriate policy. Unfortunately, this task is one that most physicians still find awkward, in part because of the continued de-emphasis of "soft" clinical skills in the medical education. Thus, doctors have little opportunity to address their own beliefs and emotions. By being cognizant of clinician unease and using well-described communication skills, however, disclosure can be satisfactorily accomplished. As American health care becomes increasingly ambulatory in nature, primary care physicians will have even more need to hone this skill.


The pathologist's role in the diagnosis of cancer. This brief overview of the activities of the pathologist for cancer patients has shown the primary care physician not only what is involved for the office patient, but also procedures that are out of the scope of office practice. It is intended that this review lead to better patient care through communication and cooperation.


Diagnostic imaging in cancer.

Diagnostic imaging in cancer. Screening chest radiographs do not reduce mortality from lung cancer. Should an incidental noncalcified pulmonary parenchymal nodule be discovered, chest CT will demonstrate one third of such patients to, in fact, have the multiple nodules of metastatic disease. CT is very helpful to guide fine needle aspiration biopsy of lung lesions and to assist in evaluation for resectability. MR can be helpful in special circumstances, including the definition of the extent of paravertebral, superior sulcus, and diaphragmatic lesions. Endorectal ultrasound is not sensitive enough to function as a screening tool for prostate cancer but is used routinely to guide biopsies. CT and MR are rarely helpful in staging this disease. Given the highly characteristic trait of bone metastasis in prostate cancer, a bone scan is mandatory in all patients. Double contrast barium enema can be used as an adjunct or alternative to sigmoidoscopy for colorectal cancer screening, in the preoperative evaluation of patients, and in postoperative surveillance. CT and MR can detect macroscopic adenopathy and liver metastases; CT is generally the preferred study. Screening mammography can have a major impact in reducing breast cancer mortality. It is recommended that a baseline study be obtained at age 35. Annual or biannual examinations should commence at age 40. Any palpable lesion, whether or not it is demonstrated mammographically, must be subjected to biopsy. Ultrasound is the most useful initial imaging study for evaluating pelvic masses. MR will, on occasion, identify the origin of a mass not determinable from ultrasound scan. MR is particularly valuable to identify parametrial spread (inoperability) of cervical cancer, and has been underused for this purpose. Surgery remains the mainstay for the staging of ovarian and endometrial cancer, although CT can be helpful to identify macroscopic relapse, ascites, or liver metastases. Bone scan and liver CT remain the standard procedures for detecting metastases in these respective organ systems. MR can be invaluable in the imaging of epidural metastasis and spinal cord compression in patients with vertebral metastatic disease. Contrast-enhanced MR is more sensitive than contrast-enhanced CT for detecting brain metastases, but the latter remains a useful tool. Chest CT can improve the detection of pulmonary metastases when this is of crucial importance.


Paraneoplastic syndromes for the primary care physician. To summarize, we have reviewed the major endocrine, hematologic, neurologic, dermatologic, and miscellaneous paraneoplastic syndromes. These entities are of great importance to the primary care physician because, when recognized, they can permit early diagnosis of the neoplasm. Further, treatment can afford palliation of symptoms. We can expect more definite identification of the causes of the paraneoplastic syndromes in the future because more of the substances that are released by tumors will be identified and analyzed. We need to watch with anticipation for the development of specific treatments for the paraneoplastic syndromes as the causes are identified.


Metastasis of unknown origin.

Metastasis of unknown origin. Evaluation of the patient with metastasis of unknown origin should be structured to quickly identify treatable tumors or the need for palliation while avoiding prolonged hospital stays and testing that will result in neither improved treatment nor better prognosis. The evaluation should be symptom-directed and pathologically oriented. It is the responsibility of the family physician in caring for a patient with MUO to ensure that communication is facilitated between surgeon, oncologist, pathologist, and patient. The physical examination should include thyroid, breasts, pelvic, and rectal examinations. General lab analyses should include fecal occult blood testing, complete blood count, urinalysis, serum calcium, and liver function studies. Men should have assays for prostate-specific antigen and serum prostatic acid phosphatase. Women should undergo mammography and pelvic ultrasound. Undifferentiated carcinoma is likely to originate from either small cell bronchogenic, lymphoma, or germ cell, and thus, serum should be assayed for HCG and AFP. Further radiologic studies, in the absence of specific symptoms, should be limited to chest radiographs and abdominal CT. Contrast studies should be included only if there is organ dysfunction. Biopsy of the malignant tissue should be done early, and studies should include histochemistry, immunohistology, and electron microscopy. Tissues from female patients should be studied for estrogen and progesterone receptors. When a biopsy is planned, advance communication between the family physician or surgeon and the pathologist greatly increases the chance of identifying a primary site. It is important that the surgeon obtain sufficient material to enable study, not only by standard histologic techniques, but also by electron microscopy, special stains, estrogen receptor activity, hormonal markers, and tumor markers. Treatment of patients for whom a primary tumor remains undiscovered must include toxic therapies only for those with good functional status who are likely to respond. Therapy must be pursued for palliation of symptoms when they develop. As physicians, we must control the urge to do something at those times when doing nothing is more appropriate. We must provide continuous support for both the patient and family, protecting to the best of our ability their quality of life. A physician should never convey the impression that it is "not cost-effective" to look for the source of a patient's malignancy. It can be emphasized that further search for a primary tumor carries both medical risk and expense, yet is unlikely to locate the primary tumor or improve the response to therapy or the quality of life.(ABSTRACT TRUNCATED AT 400 WORDS)


Cancer drug therapy.

Cancer drug therapy. The chemotherapeutic treatment of cancer has evolved into a major treatment modality. Better results than ever before are being recorded with the integration of this approach into the early and total management of cancer. Although complex and toxic, these drugs and their combinations are contributing in new ways to the treatment of more and more patients. More than 50% of those people afflicted with cancer in 1991 became long-term survivors. Most of these survivors are destined to be followed on a long-term basis by their family doctor.


Cancer survivors.

Cancer survivors. Cancer survivorship is becoming a newly defined entity. Cancer therapies can produce many late physical effects by adversely affecting every organ system. Psychosocial issues that have been studied include: psychiatric, self-concept, school performance, and behavioral adjustment, employment and insurance discrimination, and marital status. Quality-of-life assessments in adult survivors is comparable to controls but is diminished for children with disease or treatments that affect the CNS. The greatest fear for cancer survivors is the 10 to 20 times greater risk of SMN as compared with persons with no history of cancer. Infertility and sexual dysfunction are real concerns for survivors that usually go unexpressed. Some cancers have a familial predisposition; however, treatments do not appear to increase the risk of birth defects or childhood cancers in the offspring. Lower socioeconomic status adversely affects cancer survival because of lost opportunities for cancer screening, other diseases, and untreated cancer. The primary care physician can competently care for cancer survivors and should emphasize health promotion and risk prevention behaviors, topics especially applicable for this patient population.


Pain management in advanced cancer.

Pain management in advanced cancer. This article presents a primary care approach to pain management in patients with advanced cancer. Assessment of "total" pain is reviewed along with interdisciplinary care. Pharmacologic and nonpharmacologic therapies are outlined, with emphasis on the correct use of narcotics and adjuvant analgesics.


Hospice care.

Hospice care. Hospice care is a philosophy and system of care for the terminally ill patient that accepts death in an affirmative way and provides palliative care and emotional support to dying patients and their families. The primary care physician needs to better understand the hospice concepts, the reasons for and growth of hospice care, and the depth of resources that can assist in equality management of the terminally ill.


Ethical issues in the care of cancer patients. Nearly all the topics considered by medical ethics generally present themselves to those caring for cancer patients. Although most attention may be given to questions of resource allocation and limiting treatment, other issues are of equal importance. Providing respect and compassion for patients may be even more important. The day-to-day treatment of the patient that recognizes the practical autonomy of the patient and legitimizes the patient's involvement in deciding about his or her own care may do more to preserve the integrity of the patient as a person than anything else that happens to someone who accepts the cancer diagnosis. The physician who can accept the patient's judgment and participation and who can help the patient find positive meaning in what can be a personally and socially devastating disease experience has enacted a highly laudatory ethical standard of patient care.


The family with a member who has cancer. Optimal medical care for persons with chronic illnesses such as cancer cannot be provided unless the physician adopts a family-oriented approach to patient care. Such an approach requires little additional time or effort but profoundly affects the ability of patient and family to cope with cancer. Physicians should routinely gather data about the family system of their patients with cancer and make use of that data in understanding the unique issues the patient will face in adapting to their illness. The physician's goal should be to anticipate how the illness will affect the family at its current stage of the life cycle and recognize how the patient's family is currently affecting the patient's experience of the illness. The maintenance of clear, open communication among patient, family, and physician is critical to successful adaptation.


Leukemias and lymphomas in children.

Leukemias and lymphomas in children. Leukemias and lymphomas, the most common type of neoplasms in children, represent a heterogenous group of diseases that display a wide spectrum of clinical, morphologic, immunologic, cytogenetic, and molecular features. Modern treatment is curative for most children with lymphoid neoplasms; however, new approaches to therapy of acute nonlymphoblastic leukemias are necessary if current results are to be improved. This article focuses on the clinical and biologic characteristics, and the modalities of treatment of this group of diverse diseases.


Pathological lesions following an experimental intoxication with aflatoxin B1 in broiler chickens. A follow-up of chickens dosed orally over 21 days with 0.2 and 3 micrograms of aflatoxin B1 (AFB1) g-1 of bodyweight daily and their subsequent recovery 10 days after withdrawal of contaminated food was conducted. Vacuolation of liver cells during the initial days of the intoxication and cellular depletion in the follicle medulla of the bursa of Fabricius were the lesions which appeared first and persisted during the recovery phase in both groups of intoxicated animals. The intensity of these lesions and their persistence was related to the dose of aflatoxin ingested. A significant reduction in the bodyweight and absolute weights of liver, bursa of Fabricius spleen and thyroid was observed in the higher dose group.


Tannic acid intoxication in sheep and mice. Acute tannic acid intoxication was studied in mice and sheep. In mice, following oral administration of 2.0 to 4.6 g of tannic acid kg-1 bodyweight, periacinar coagulative and haemorrhagic necrosis occurred in the liver. In sheep, following oral (8 g kg-1 bodyweight) administration of tannic acid, liver necrosis was not observed either histologically or detected biochemically, although transmission electron microscopy showed focal hepatocellular necrosis, steatosis and acicular crystal cleft formation. In sheep given tannic acid intraperitoneally (0.1 g kg-1 bodyweight), liver necrosis occurred and plasma sodium and glucose levels significantly (P < 0.05) decreased while packed cell volume and plasma aspartate aminotransferase, alkaline phosphatase, creatinine and bilirubin significantly (P < 0.01) rose. The results for blood-gas and acid-base determinations, blood haemoglobin and oxygenation showed significant increases in arterial blood methaemoglobin concentration (P < 0.05) and decreases in blood pH (P < 0.01) and oxyhaemoglobin concentration (P < 0.05) in sheep by 32 hours after oral dosing with 8 g of tannic acid kg-1 bodyweight. In sheep given tannic acid intraperitoneally, methaemoglobinaemia was not detected, but metabolic acidosis with a compensatory respiratory alkalosis occurred. Thus, it would appear that although tannic acid is hepatotoxic when given orally to mice or intraperitoneally to sheep, it does not produce renal or significant hepatic injury in sheep when given orally, but rather causes metabolic acidosis and methaemoglobinaemia.


Immune responses to dietary antigens in gluten-sensitive enteropathy of Irish setters. This study examined whether increased intestinal permeability in Irish setters with gluten-sensitive enteropathy was associated with altered immune responses to ingested antigens, and whether a humoral immune response to gluten is involved in the pathogenesis of the condition. Affected setters reared on a wheat-containing diet were compared with littermates reared on a cereal-free diet and age-matched control setters. Measurement of serum immunoglobulins revealed increased serum IgA concentrations in affected dogs. Antibody responses to a variety of dietary antigens were measured by ELISA. Antibody levels to ovalbumin, collagen I and II and soya were not significantly different from normal dogs. Anti-gliadin antibody concentrations were lower in affected dogs than controls, and correlated with immune complex formation as assessed by C1q binding. The study suggested a modified immune response in dogs with increased intestinal permeability, although there was no major systemic antibody response to dietary antigens.


Reactivity of lichen lectins with blood typed canine erythrocytes. Extracts from 69 species of lichens were tested for their ability to agglutinate untreated and enzyme-modified erythrocytes from a panel of blood typed dogs. Forty-three lichen species reacted positively with either untreated or enzyme-modified cells. Many extracts exhibited differential agglutination among red cells tested. The patterns of differential agglutination observed with the lichen extracts did not correspond to known canine blood groups present on the test red cell panel.


The effect of copper and heliotrope on the composition of bile in sheep. The effects of interrupting the enterohepatic circulation (EHC) of bile salts for seven hours and of feeding copper and heliotrope alone and combined for 13 weeks, on bile flow and excretion of copper, zinc, iron and alpha-mannosidase were studied in sheep. Interruption of EHC reduced bile flow rate and increased the concentration of copper, zinc, iron and bile acids while alpha-mannosidase's activity remained stable. Changes in concentration were related to changes in bile volume for copper and zinc only. Total output per hour was not changed. Biliary concentration of copper correlated with alpha-mannosidase's activity in control sheep and those given copper or heliotrope, supporting the hypothesis that lysosomes are involved in biliary secretion of copper in sheep. Increasing the intake of copper increased the rate of excretion of copper in bile. Copper output was lower when heliotrope was fed alone.


Does a single bout of exercise cause adaptation of amino acid metabolism in pigs? Amino acid responses to exercise stress in well-trained racehorses and human athletes are well characterised, but the knowledge of amino acid metabolism during and after exercise in inactive animal species is limited. To study this, plasma amino acid concentrations were measured in previously unexercised pigs which performed two exercise tests on a treadmill with an interval of one week. In general, the changes in amino acids were more pronounced after the second than after the first exercise bout. Alanine, glutamine, phenylalanine and tyrosine were elevated for one hour only after the latter exercise. Twenty-four hours after the second exercise isoleucine, leucine, phenylalanine, tyrosine and valine were increased, but only isoleucine was increased after the first test. These differences between the two tests might be explained by adaptation of the amino acid metabolism after a single exercise bout and suggest that domestic pigs are well suited to study the early effects of exercise.


Glucose tolerance and insulin secretion in spontaneously hyperthyroid cats. Glucose tolerance and insulin secretion after administration of a glucose load were determined in 11 clinically normal cats and 15 cats with spontaneous hyperthyroidism. In six hyperthyroid cats, a glucose tolerance test was repeated after treatment with radioactive iodine (131I). All cats had similar baseline glucose concentrations. However, the cats with hyperthyroidism had a significantly decreased glucose clearance, which was worse after treatment. Hyperthyroidism also caused a marked increase in basal and glucose-stimulated insulin secretion, which was not improved with treatment. It is concluded that hyperthyroidism in cats may lead to long-lasting alterations of glucose tolerance and insulin secretion which may not be reversed by treatment.


Vaccination against experimental staphylococcal mastitis in dairy heifers. Vaccination-challenge experiments were carried out with dairy heifers using new, killed cell-toxoid-adjuvant Staphylococcus aureus vaccines. The organisms in the vaccines were cultured under conditions which simulated in vivo growth and induced expression of a pseudocapsule. Dextran sulphate which promotes synthesis of IgG2 antibody was included in the vaccines as the primary adjuvant. Vaccinated heifers developed very high levels of both IgG1 and IgG2 anti-pseudocapsule antibody in serum, however, titres of neutralising antibody against toxoided haemolysins were generally low. Vaccinated and unvaccinated control heifers were challenged by intramammary infusion of three virulent strains of S aureus in four experiments. Vaccinated heifers were more resistant to clinical mastitis following challenge than were controls, and the vaccinates had significantly greater milk production than controls following challenge. The most promising vaccine had dextran sulphate combined with mineral oil as the adjuvant injected intramuscularly.


Functional significance of the morphology and micromechanics of collagen fibres in relation to partial rupture of the superficial digital flexor tendon in racehorses. The high incidence of partial rupture of the superficial digital flexor tendor in the equine athlete represents a major cause for concern in the racing industry. Frequently, the lesion is localised to the central core of the tendon. This study tested the hypothesis that the site specific structural failure results from differences in the collagen fibre morphology and associated micromechanics between central and peripheral regions of the tendon. Bundles of collagen fibres were dissected from central and peripheral sites in the mid-metacarpal region of the tendon. Crimp morphology was quantified by polarised light microscopy and mechanical characteristics determined using a fibre tensometer. In older horses, centrally located fibres showed significantly lower values for crimp angle, crimp length and toe limit strain than seen peripherally. There were no significant differences in these features between corresponding sites in the younger horses. No significant difference between sites was found in elastic modulus in either group. These data indicate a non-uniform functional stress distribution which may result from ageing or be related to the exercise history as a feature of accumulated damage. These observations may explain the location of central core lesions seen on clinical examination.


Inhalation of water during electrical stunning in chickens. Twenty live hens were subjected to electrical stunning using a waterbath containing a solution of technetium99 (99Tc), and 12 hen carcases were injected intratracheally with different doses of the same solution. The respiratory tract was dissected from the carcases and samples were assessed for the presence of radioactivity. Thirty-five per cent of the electrically stunned birds had 99Tc in their tracheas and 15 per cent had 99Tc in the lungs. From the dose response study it was estimated that the birds with radioactivity in their lungs had inhaled between 0.5 and 1 ml of water. In commercial slaughterlines this may be a hazard to meat hygiene.


Interactions between Teladorsagia circumcincta and Trichostrongylus vitrinus infections in young lambs. Groups containing six lambs that previously had been infected five times each week for four, eight or 12 weeks, either with 1000 Trichostrongylus vitrinus third stage larvae (L3) or 1000 T vitrinus L3 and 2500 L3 Teladorsagia (previously Ostertagia) circumcincta were challenged, along with six worm-free control lambs, with 3000 75Se-labelled T vitrinus L3. The lambs were killed 10 days after challenge. Those given a dual infection for four and eight weeks had significantly lower total T vitrinus numbers than monospecifically infected lambs. Significantly fewer radiolabelled larvae were recovered from the dual infected group killed after four weeks exposure to infection than from lambs infected monospecifically. The negative interaction between these two nematode species appears to be physiologically mediated and may be an important factor in accounting for differences in their seasonal prevalence.


Evidence of multiple anthelmintic resistance in a strain of Teladorsagia circumcincta (Ostertagia circumcincta) isolated from goats in Scotland. The efficacy of ivermectin, fenbendazole and levamisole was determined in lambs individually infected with 5000 third stage larvae of Teladorsagia (Ostertagia) species isolated from a herd of goats with a history of benzimidazole resistance and where the efficacy of ivermectin had also suffered an apparent decline. Efficacies, calculated using geometric means, for groups where treatments were directed against adult worms were 90.3 per cent (ivermectin), 43.4 per cent (fenbendazole) and 100 per cent (levamisole). The efficacy of ivermectin against immature stages was 83.2 per cent. Ivermectin was highly effective (99.9 per cent) against a known susceptible ovine strain of Teladorsagia.


Stress factors influencing plasma cortisol levels and adrenal weights in Chinese water deer (Hydropotes inermis). Stress responses were compared in Chinese water deer (Hydropotes inermis) exposed to different handling, management and disease factors by measuring plasma cortisol and adrenal gland weight. Healthy free-ranging deer shot as part of a management programme served as baseline controls; they had lower cortisol levels than either diseased deer or free-ranging deer that were either netted and manually restrained or anaesthetised by dart. Although darting appeared subjectively to be much less stressful to the deer than manual restraint, there was no significant difference in cortisol levels between the two groups. Hand-reared deer that were manually restrained in a similar manner to the free-ranging deer did not react behaviourally any less violently but showed significantly lower plasma cortisol levels. Adrenal glands of deer with various, mostly chronic, disease conditions weighed significantly more than those of healthy deer.


Sequential in vivo measurements of body composition of calves exposed to natural infection with gastrointestinal nematodes. Sequential in vivo measurements of total body water, exchangeable sodium and exchangeable potassium, made by radioisotopic dilution techniques, were used to determine changes in body composition in calves exposed to natural infections with gastrointestinal nematodes during their first grazing season. Two groups of calves were studied, one of which received a sustained release anthelmintic bolus at turn out. Over the grazing season the bolus-treated calves showed a significantly improved pattern of bodyweight gain, compared with the untreated control calves. There were also significant increases in both total body water and exchangeable potassium, as a percentage of the bodyweight, in the bolus calves compared with the controls. These findings indicated that body protein as a percentage of bodyweight was increased in the bolus animals. The bolus-treated calves also had significantly lower serum pepsinogen concentrations, faecal egg counts and worm burdens.


Antigenic differences between the life cycle stages of Cooperia oncophora. The antigenic differences among the life cycle stages of Cooperia oncophora were studied by SDS-gel electrophoresis and Western blotting. Sodium dodecylsulphate polyacrylamide gel electrophoresis of the different life cycle stages of C oncophora revealed a complex protein pattern with a decreasing number of protein bands towards the adult stages. Several bands of the fourth stage larvae were in common with both the third stage and the adult nematode. Western blotting with sera from C oncophora monoinfected calves showed that the antigens of the fourth stage larvae were recognised predominantly and the presence of stage specific antigens in all stages. Strong cross reactivity was demonstrated when serum from Ostertagia ostertagi infected calves was used.


Preparation and use of a monoclonal antibody to detect Chlamydia psittaci antigen in paraffin-embedded tissue sections. A murine monoclonal antibody prepared against an ovine abortion isolate of Chlamydia psittaci (A22/Teramo) revealed specific binding to a 57 kDa chlamydial antigen in immunoblotting studies. The monoclonal antibody was able to detect intracytoplasmic chlamydial inclusions and scattered elementary bodies in infected McCoy cell culture, and on formalin-fixed paraffin-embedded tissue sections both from experimentally infected mice and from fetal membranes of cases of ovine enzootic abortion.


Changes in some biochemical indicators of bone turnover after ultraviolet irradiation of dairy cows. The effect of ultraviolet irradiation on some biochemical indicators of bone turnover in dairy cows was determined. The irradiation was performed using a stationary system for two months and comprised a regimen of 10 days irradiation followed by 10 days rest. After ultraviolet irradiation, significant differences in the activities of serum alkaline phosphatase (P < 0.001) and bone alkaline phosphatase isoenzyme (P < 0.05) and concentration of osteocalcin (P < 0.01) were demonstrated. The results suggest that supplementary ultraviolet irradiation during winter could be used as a simple but reliable method of preventing the development of generalised metabolic bone disorders in dairy cows.


Occurrence of retrovirus-like particles in various cellular and intercellular compartments of the venom glands from Bothrops jararacussu. Retrovirus-like particles were detected in venom glands from Bothrops jararacussu during electron microscopy. Type C-like particles were found inter- and intracellularly in gland and vessel lumina and scattered in the connective tissue. They were about 100 nm in diameter, with an electron dense core and bilaminar external membrane. Shapes suggestive of a budding process from the plasma membrane were also observed. Less frequently, type A-like particles, about 80 nm diameter with an electronlucent core, appeared in association with the membranes of the endoplasmic reticulum of the secretory cells.


[Drug-induced hyperprolactinemia and galactorrhea]. A 21 year old female treated for recurring gastric troubles with dopamine-antagonists (domperidone, metoclopramide) developed a clinically manifest hyperprolactinemia (3055 microU/l; normal value < 650 microU/l) with galactorrhea only two days after a new two day course of metoclopramide. The drug was withdrawn and within days mastodynia and galactorrhea subsided. A control of plasmatic prolactin two weeks later yielded a normal value (358 microU/l). After administration of metoclopramide or domperidone hyperprolactinemia is regularly observed and galactorrhea has been described earlier. It is unclear why this patient inspite of repeated administration of one dopamine antagonist remained asymptomatic whereas the other after a short time and only a few doses led to galactorrhea. It is conceivable that differences in passage into the cerebrospinal fluid or the better penetration of the blood-brain barrier favored the development of galactorrhea under metoclopramide. This case served to discuss the pathophysiologic background of drug-induced hyperprolactinemia.


[Evaluation of the antihypertensive efficacy of isradipine SRO as assessed by ambulatory blood pressure determination]. The calcium channel blocker isradipine has become recently available in a form with delayed release (isradipine SRO). The anti-hypertensive efficacy and tolerance of this preparation at a single daily dose of 5 mg was studied in 40 patients with uncomplicated essential hypertension over a period of 6 weeks. Blood pressure during office visits decreased under Isradipine SRO from 164/105 +/- 16/7 to 144/93 +/- 12/7 mmHg (mean +/- 1 standard deviation p < 0.001). Using ambulatory blood pressure recording we could show that antihypertensive efficacy of the new galenic form persisted over 24 hours. During the day the blood pressure dropped from 150/95 +/- 13/7 to 141/91 +/- 13/7 mmHg (p < 0.001), during the night from 131/85 +/- 13/3 to 121/81 +/- 15/9 mmHg (p < 0.001). Heart-rate was not changed by treatment and the drug was well tolerated. Isradipine SRO at a single dose is thus well suited for antihypertensive treatment.


[Sympathy, desire and physical attraction in the student-patient relationship. Encounter with Mrs. Kelley during my internship]. During an internship in pneumology the author made the acquaintance of Mrs. Kelley, a young and likeable patient. While taking the history he experienced the development of a subtle erotic tension between them. When her husband and children joined them Mrs. Kelley preferred to be examined physically and sent her family out of the room. This situation made the student insecure and he could no longer approach this patient like other patients. This article contains reflections on the incident which helped the author to cope with that particular incident and comparable situations. He also developed proposals to include this aspect in the medical curriculum.


[Psychophysical load of students in the first year of community secondary schools]. The material comprised 179 first-grade pupils (92 girls and 87 boys) of private high-schools in several big cities. The psychophysical load of pupils was evaluated using a standard questionnaire containing 77 questions. These questions were arranged in groups allowing for estimation of psychophysical load related to school lessons, extracurricular activities, daily timetable, pupil's situation in the class and family, and his psychic feeling. The results were treated statistically; moreover, they were compared with the results of earlier studies on 518 first-grade pupils (346 girls and 172 boys) of public high-schools in the same cities. The results lead to the following conclusions: In both private and public high-schools the psychophysical load of girls exceeded that of boys. Likewise, the objectively existing load-causing situations and subjective feelings of the troublesomeness of these situations were a greater nuisance to girls. Psychophysical loads of these girls and boys were somewhat slighter in private than in public high-schools. This decrease in psychophysical load of girls and boys attending private high-schools is associated with smaller loads related to school lessons and to the pupil's situation in the family and class, as well as is due to his better psychic feeling. Loads related to extracurricular activities were similar for girls and boys, irrespective of the kind of high-school. Loads associated with school timetable were in private schools similar for girls and boys, whereas in public schools they were somewhat higher for girls.


[Quality, accreditation and certification in free-market economy. Part II. Quality, accreditation and certification in light of European standards]. Process of accreditation and certification on the ground of series of European standards EN 45000 was discussed. Purpose of establishing, subject and field of application of these standards were presented. Current legal situation in Poland in the domain of accreditation and certification was described.


[Residues of organochlorine insecticides in foods in the years 1986-1990]. During 1986-1990 4625 samples of food commodities were examined for residues of organochlorine (OC) insecticides in 10 provinces in Poland. This monitoring included analysis of total DDT (DDT+DDE+DDD), alpha, beta and gamma-HCH, HCB and Methoxychlor (DMDT) in milk and milk products, fruits, vegetables, vegetable oils and baby foods. The median values for DDT in milk and milk products varied from undetectable to 0.23 mg/kg on fat basis, and the draft national tolerance (1.0 mg/kg) was exceeded in 2-5% of samples in 1986 only. In fruits and vegetables the median concentrations of the total DDT usually were below the limit of determination. Generally, during the five years period the downward tendency in DDT complex concentration was observed, but not in case of the total HCH. The residues of OC insecticides in baby foods were generally very low due to establishing of special "low-pesticide" areas for growing raw materials for these products.


[Quality, accreditation and certification in free-market economy. Part I. Quality and quality assurance systems according to international standards]. The problems concerning the quality and quality assurance systems were discussed on the base of the International Standards series ISO 9000. The structure, scope and the field of application of these Standards were described. The special attention has been drawn to the models of quality assurance specified in ISO 9001, ISO 9002 and ISO 9003. The role of the International Standards series ISO 9000, as a useful tool to harmonize the international trade in free-market economy was stressed. It was emphasized that the application of quality management and quality assurance systems according to ISO 9000 is compatible with the implementation of Hazard Analysis Critical Control Point (HACCP) system in the food industry.


[Changes in nitrate levels and nitrates in carrot roots during storage in an earthen clamp]. The aim of this study was the determine the nitrate and nitrite contents in edible parts of 5 varieties of carrot, before clamping and after uncovering, in fresh carrot and dry matter. The colorimetric methods of Griess with modified by Romminger and Straus were used. Dry matter was determined with a drier. Statistical significance of differences in the levels of the studied compounds was calculated by a two-ways analysis of variance. In the studied carrot before clamping average 406.6 mg KNO3/kg and 4.1 mg NaNO2/kg of fresh product was found. These amounts considerably admissible values. After 6-month storage a statistically significant decrease in nitrate levels of Karlena, Perfekcja and Amager was found, in dry matter, whereas a statistically significant increase in Koral variety, while no statistically significant difference in the nitrate level did not changes, was found in Bercoro variety. As concerns nitrites a statistically significant decrease was stated in all carrot varieties.


[Influence of meat storage at +2 degrees C I - 18 degrees C on the activity of OTC residues]. The examinations were carried out on meat of rabbits which had been being given therapeutical doses OTC (3 x 30 mg/kg i.m.). Rabbits were slaughtered after 4 hours since the last injection. The highest residues of OTC were found in kidneys, lower in liver and the lowest in muscles. The activity of OTC residues was observed in the kidneys, liver and muscles for 21 days stored at +2 degrees C and for 90 days at -18 degrees C. During the storage residues of OTC decreased more dynamically in kidneys and liver than in muscle tissue.


[Nutritional value of daily diets prepared in several regions of the country. Part VI. Value of retinol, beta-carotene and vitamin E]. Determinations of retinol, beta-carotene and vitamin E were carried out in daily diets of manual and mental workers with medium incomes. The diets were prepared on the basis of the analysis of the Central Statistical Office in 1986 under laboratory conditions in five regions of Poland (Warszawa, Lublin, Olsztyn, Poznań, Wrocław). It was found that these diets contained respectively: vitamin A (retinol and beta-carotene) 844 and 859 micrograms, retinol 466 and 496 micrograms, beta-carotene 2267 and 2167 micrograms and vitamin E 4.82 and 5.12 mg per day. In relation to the realization of daily recommended dietary allowances by these diets, for vitamin A were met respectively 102 and 104% and for vitamin E 58 and 61%. There were considerable differences in the content of beta-carotene and vitamin E between diets prepared in all five regions of Poland.


[Some elements of methods used for nourishing school children in the town of Poznan after development of market economy]. Studies were aimed at evaluation of nutrition of primary school pupils, 11-14 years of age. It was shown that the daily food rations fail to comply with the recommended nutritional standards for nearly all nutrients, and do not meet the norms of sufficient nutrition. analysis of the food consumption structure testified to very high differentiation of nutrition in the investigated group; this is doubtless related to the family's income levels. The results point to the need for food supplementation at schools.


[Gliadin determination in gluten-free products by the ELISA method]. Immunoenzymatic method with rabbit antibodies against gliadin and antibodies conjugates with peroxidase for gliadin determination in gluten-free food using polypropylene and polystyrene was successfully used. Results of gliadin determination indicate that content of gliadin in investigated samples was low--about 0.1%.