Two cases of chlorinated hydrocarbon-associated myocardial ischemia

Chlorinated hydrocarbons are well known to produce ventricular arrhythmias because of myocardial sensitization to endogenous catecholamines, but cases of myocardial ischemia have not been described frequently. We report 2 cases of myocardial ischemia after exposure to chlorinated hydrocarbons. The first patient developed an asymptomatic myocardial infarction after inhalation of 1,1,1-trichloroethane at work. It is believed that 1,1,1-trichloroethane produced a coronary spasm that was sufficient to cause myocardial necrosis in the presence of coronary vessels already compromised by atherosclerosis. The second patient developed a reversible symptomatic myocardial ischemia of 4 h duration after chloral hydrate overdose. The evolution in both patients was favorable. Exposure to chlorinated hydrocarbons can be associated with myocardial ischemia particularly if the coronary circulation is already compromised.

Event-related potentials associated with judgment: comparison of S1- and S2-choice conditions in a contingent negative variation (CNV) paradigm

To elucidate the functional role of association cortex in judgment and decision-making about external stimuli, the scalp topography of contingent negative variation (CNV) recorded in 9 normal volunteers was compared in two settings; dichotomous S1- and S2-choice paradigms using right wrist extension or flexion movement upon S2 as the choice reaction task with an S1-S2 interstimulus interval of 2 s. Two main findings were obtained. First, early CNV in the S1-choice paradigm consisted of a frontal to frontopolar midline negative potential, most likely representing judgment more than orienting response, and a left-sided parietal positive potential, at least partially representing P3b, whereas in the S2-choice paradigm it consisted only of a smaller frontal negative potential shift, most likely representing merely an orienting response. This suggests that the prefrontal and left parietal association cortexes might be active in the judgment and decision-making process. Second, after S2, two positive peaks (334 and 545 ms after S2) were observed at the midline central to left parietal areas only in the S2-choice paradigm. In the S1-choice paradigm, one large negative peak (275 ms after S2) was observed. We postulate that the first peak of the S2-choice paradigm is related to decision making or judgment and that the second peak is related to the following cognitive process. We conclude that at least the prefrontal and parietal association cortexes generate transient potentials accompanying judgment, and possibly decision making.

[The role of MPO mRNA, IgH mRNA and CD3epsilon mRNA expressions in classification of acute leukemias]

OBJECTIVE

To compare the role of genotypic and immunophenotypic markers in classification of acute leukemia.

METHODS

Expression of myeloperoxidase (MPO), CD3epsilon chain and immunoglobulin heavy chain (IgH) gene in 69 cases of acute leukemia were studied by in situ hybridization with streptavidin-gold (ISH-SAG).

RESULTS AND CONCLUSION

MPO mRNA and CD3epsilon mRNA expressions were specific for early diagnosis of AML and T-ALL, respectively; and IgH mRNA expression did for early B cell leukemia. Combination of genotypic and immunophenotypic markers assured accurate lineage diagnosis of leukemias.

Prevalence of sleep-disordered breathing in diastolic heart failure

OBJECTIVE

Sleep-disordered breathing (SDB) is common in congestive heart failure. While isolated diastolic heart failure (DHF) accounts for up to a third of all cases of congestive heart failure, the prevalence of SDB in DHF is unknown. We aim to determine the prevalence and characteristics of SDB in a group of patients with symptomatic DHF.

METHODS

Twenty subjects with symptomatic DHF (New York Heart Association class II or III) and isolated diastolic dysfunction on echocardiography were assessed with lung function tests, modified sleep and health questionnaire, and overnight polysomnography. Significant SDB was defined as an apnea/hypopnea index (AHI) > 10.

RESULTS

Thirteen female and seven male subjects (mean age, 65+/-6.0 years; mean body mass index (BMI), 28+/-3.2) were evaluated, of whom 17 (85%) had a diagnosis of hypertension. Overall sleep quality was poor, with fragmentation and frequent arousals associated with respiratory events. Fifty-five percent of the patients had significant SDB, mainly obstructive apneas. BMI and the prevalence of hypertension were similar in patients with and without SDB. The deceleration time, an index of diastolic dysfunction, was more prolonged in the group with SDB (236+/-40 ms vs 282+/-31 ms; p<0.05). As a group, a lower minimum percentage arterial oxygen saturation during sleep, but not the AHI was associated with more severe degree of diastolic dysfunction on echocardiogram, including a lower ratio between the early peak transmittal flow velocity and the late peak atrial systolic velocity (rho=0.57; p<0.05) and a prolonged isovolumic relaxation time (rho=-0.54; p<0.05).

CONCLUSIONS

SDB is common in patients with DHF. Patients with DHF and SDB may be associated with worse diastolic dysfunction than those without SDB, although a causal relationship remains to be established.

Neuregulin-2, a new ligand of ErbB3/ErbB4-receptor tyrosine kinases

The neuregulins (NRGs) are a family of multipotent epidermal-growth-factor-like (EGF-like) factors that arise from splice variants of a single gene. They influence the growth, differentiation, survival and fate of several cell types. We have now discovered a set of new neuregulin-like growth factors, which we call neuregulin-2 (NRG-2): these are encoded by their own gene and exhibit a distinct expression pattern in adult brain and developing heart. Like NRG-1, the EGF-like domain of the new ligands binds to both the ErbB3- and ErbB4-receptor tyrosine kinases. However, NRG-2 stimulates different ErbB-receptor tyrosine-phosphorylation profiles from NRG-1. Our results indicate that NRG-1 and NRG-2 mediate distinct biological processes by acting at different sites in tissues and eliciting different biochemical responses in cells.

Protein tyrosine kinase inhibitors decrease lipopolysaccharide-induced proinflammatory cytokine production in mixed glia, microglia-enriched or astrocyte-enriched cultures

Proinflammatory cytokines, tumor necrosis factor-alpha (TNF alpha), interleukin-1 (IL-1), and interleukin-6 (IL-6), produced by glial cells have been implicated in the neuropathogenesis of various diseases. However, the signal transduction pathway(s) for the production of these cytokines in glial cells are not well understood. This study examined the effects of two potent protein tyrosine kinase inhibitors, genistein and tyrphostin A25, on lipopolysaccharide (LPS)-induced production of TNF alpha, IL-1 alpha, and IL-6 in mouse primary mixed glia, microglia- or astrocyte-enriched cultures. LPS dose-dependently increased the production of TNF alpha, IL-1 alpha, and IL-6 from the mixed glia cultures. Genistein or tyrphostin A25 significantly inhibited the LPS-induced production of these cytokines. The LPS-induced TNF alpha, IL-1 alpha, and IL-6 production in microglia- or astrocyte-enriched cultures were also inhibited by tyrphostin A25. These results demonstrate that protein tyrosine kinases are involved in the signaling events of the LPS-induced production of TNF alpha, IL-1 alpha, or IL-6 in microglia or astrocytes, which may provide insights into therapeutic interventions in the pathway for cytokine production in the brain.

[Transfer and expression of rh-SCF gene in human hematopoietic stem/progenitor cells]

OBJECTIVE

To explore the transfer and expression of recombinant human stem cell factor (rh-SCF) gene in human hematopoietic stem/progenitor cell.

METHODS

pLXSN-SCF, a recombinant retrovirus vector of soluble human SCF gene, was constructed by recombinant gene technique. The recombinant plasmid was introduced into virus packaging cells psi2 and PA317 by lipofectin-mediated DNA transfection, and PA317/SCF, the recombinant virus producing cell, was obtained by G418 screening [the virus potency was (2.4-8.5) x 10(5) CFU/ml]. Then, human hematopoietic stem/progenitor cells were transfected with PA317/SCF. The transfer and expression of human SCF gene were assayed by PCR, APAAP immunohistochemical staining and chemoluminance-direct ELISA.

RESULTS AND CONCLUSION

retrovirus-mediated rh-SCF gene was successfully transferred and expressed in human hematopoietic stem/progenitor cells.

Non-promoting effects of iron from beef in the rat colon carcinogenesis model

Significant alarm has existed among the general public in the past few years that eating red meat may cause human colon cancer. Iron in beef has been hypothesized as one of the factors in the etiology of this cancer. The present study was designed to test the hypothesis that dietary iron solely from beef would enhance colon tumorigenesis induced in rats. Tumors were induced in Sprague-Dawley rats with 1,2-dimethylhydrazine (20 mg/kg body weight for 10 weeks). Seventy male weanling rats were randomized to two dietary treatment groups with two iron sources (very lean beef vs. iron citrate) as the factor. The rats were allowed free access to the respective diet and deionized water for 27 weeks. At termination of the study, the rats were examined for location, size and type of colon or extracolonic lesions. No significant differences were found in total incidence and number of colon tumors between the beef (51.7%, 0.8 tumors/rat) and casein (62.1%, 0.9 tumors/rat) diets, although the serum iron levels of rats fed the beef diet were higher than for those fed the casein diet. The results demonstrate that, when lean beef is used as an iron source, the risk for colon carcinogenesis is not increased.

Ferrous iron uptake but not transfer is down-regulated in Caco-2 cells grown in high iron serum-free medium

Caco-2 cells in culture provide an attractive model for the study of human iron absorption. Because iron status has a marked effect on human iron absorption, we devised serum-free growth conditions that allow manipulation of Caco-2 cell iron stores while maintaining growth. Caco-2 cells were cultured in serum-free media containing 0-20 micromol/L added iron. Intracellular ferritin, measured by radioimmunoassay, increased 100-fold with the addition of 20 micromol/L iron to the serum-free growth medium. Iron uptake and transfer across Caco-2 cell monolayers were measured from balanced salt solutions of ferrous and ferric forms of iron. Uptake from ferrous, but not ferric, iron was inversely related to cell ferritin concentration and culture medium iron concentration. Kinetic analysis of uptake data from solutions of ferrous and ferric iron revealed saturable and nonsaturable components for ferrous iron, but only a nonsaturable component for ferric iron. Uptake by the nonsaturable pathway was not affected by cell ferritin concentration for either form of iron. Maximal uptake from a ferrous iron solution via the saturable pathway was nearly 100% greater in cells cultured under low compared with high iron conditions. Iron transfer across Caco-2 monolayers was not proportional to iron uptake, but was related to monolayer permeability. Iron uptake by Caco-2 cells was a reliable indicator of relative iron availability. We observed no difference in iron transfer that was related to the iron status of the cell monolayer. The lack of this effect suggests that this model may be inadequate for studies of iron transfer.

Characterization of the functional properties of env genes from long-term survivors of human immunodeficiency virus type 1 infection

A small number of persons infected with human immunodeficiency virus type 1 (HIV-1) remain clinically and immunologically healthy for more than a decade after infection. Recent reports suggest that these individuals may be infected with an attenuated strain of HIV-1; however, a common genetic basis for viral attenuation has not been found in all cases. In the present study, we examined the functional properties of the HIV-1 env genes from six long-term survivors. env clones were generated by PCR amplification of proviral env sequences, followed by cloning of the amplified regions into expression vectors. Eight to ten clones from each subject were screened by transient transfection for expression of the envelope precursor glycoprotein, gp160. Those clones expressing gp160 were then cotransfected with an HIV-1 luciferase reporter vector, pNL4-3Env(-)LUC(+) and evaluated for their ability to mediate infection of phytohemagglutinin-activated peripheral blood mononuclear cells in single-cycle infectivity assays. Clones expressing gp160 were identified for all six long-term survivors, indicating the presence of proviral env genes with intact open reading frames. For two subjects, D and DH, the encoded envelope glycoproteins yielded high levels of luciferase activity when pseudotyped onto HIV-1 virions and tested in single-cycle infectivity assays. In contrast, envelope glycoproteins cloned from four other long-term survivors were poorly processed and failed to mediate infection. Sequencing of the gp120/41 cleavage site and conserved gp41 cysteine residues of these clones did not reveal any obvious mutations to explain the functional defects. The functional activity of env clones from long-term survivors D and DH was comparable to that seen with several primary HIV-1 env genes cloned from individuals with disease progression and AIDS. These results suggest that the long-term survival of subjects D and DH is not associated with overt functional defects in env; however, functional abnormalities in env may contribute to maintaining a long-term asymptomatic state in the other four cases we studied.

Expression of the Tyro4/Mek4/Cek4 gene specifically marks a subset of embryonic motor neurons and their muscle targets

Tyro4 is a member of the eph family of receptor protein-tyrosine kinases. We present sequence analysis that identifies Tyro4 as the rat homolog of mouse Mek4 and chick Cek4. We also present expression studies that demonstrate an evolutionarily conserved pattern of expression for Tyro4, Mek4, and Cek4. Most strikingly, we find this receptor to be specifically expressed, in all three species, in a subset of motor neurons in the medial motor column and in a subset of axial, but not limb, muscles. Mek4 has previously been ascribed a role in guiding retinal axons to their targets in the optic tectum. Our results extend the purported role of Mek4 in axon guidance to include motor neurons of the medial motor column.

Neuregulin receptors, erbB3 and erbB4, are localized at neuromuscular synapses

Neuregulin (NRG) is concentrated at synaptic sites and stimulates expression of acetylcholine receptor (AChR) genes in muscle cells grown in cell culture. These results raise the possibility that NRG is a synaptic signal that activates AChR gene expression in synaptic nuclei. Stimulation of NRG receptors, erbB3 and erbB4 initiates oligomerization between these receptors or between these receptors and other members of the epidermal growth factor (EGF) receptor family, resulting in stimulation of their associated tyrosine kinase activities. To determine which erbBs might mediate synapse-specific gene expression, we used antibodies against each erbB to study their expression in rodent skeletal muscle by immunohistochemistry. We show that erbB2, erbB3 and erbB4 are concentrated at synaptic sites in adult skeletal muscle. ErbB3 and erbB4 remain concentrated at synaptic sites following denervation, indicating that erbB3 and erbB4 are expressed in the postsynaptic membrane. In addition, we show that expression of NRG and erbBs, like AChR gene expression, increases at synaptic sites during postnatal development. The localization of erbB3 and erbB4 at synaptic sites is consistent with the idea that a NRG-stimulated signaling pathway is important for synapse-specific gene expression.

Aberrant neural and cardiac development in mice lacking the ErbB4 neuregulin receptor

Various in vitro studies have suggested that ErbB4 (HER4) is a receptor for the neuregulins, a family of closely related proteins implicated as regulators of neural and muscle development, and of the differentiation and oncogenic transformation of mammary epithelia. Here we demonstrate that ErbB4 is an essential in vivo regulator of both cardiac muscle differentiation and axon guidance in the central nervous system (CNS). Mice lacking ErbB4 die during mid-embryogenesis from the aborted development of myocardial trabeculae in the heart ventricle. They also display striking alterations in innervation of the hindbrain in the CNS that are consistent with the restricted expression of the ErbB4 gene in rhombomeres 3 and 5. Similarities in the cardiac phenotype of ErbB4 and neuregulin gene mutants suggest that ErbB4 functions as a neuregulin receptor in the heart; however, differences in the hindbrain phenotypes of these mutants are consistent with the action of a new ErbB4 ligand in the CNS.

[Effect of interferon on filtering blebs after trabeculectomy in rabbit eyes]

A study on the suppressive effect of interferon on the formation of filtering surgical scar was carried out. Trabeculectomy was performed on 6 rabbit eyes. 100,000 Units of interferon were subconjunctivally injected at the filtering bleb during the operation and on the 3rd and 7th post-operative day. The filtering blebs, filtering function and the scanning electron microscopic examinations of the surgical areas of the walls of the globes were observed. The results show that interferon can reduce the scar, improve filtering function and can be tried clinically.

The anticoagulation factor protein S and its relative, Gas6, are ligands for the Tyro 3/Axl family of receptor tyrosine kinases

We report the identification of ligands for Tyro 3 (alternatively called Sky, rse, brt, or tif) and Axl (alternatively, Ark or UFO), members of a previously orphan family of receptor-like tyrosine kinases. These ligands correspond to protein S, a protease regulator that is a potent anticoagulant, and Gas6, a protein related to protein S but lacking any known function. Our results are reminiscent of recent findings that the procoagulant thrombin, a protease that drives clot formation by cleaving fibrinogen to form fibrin, also binds and activates intracellular signaling via a G protein-coupled cell surface receptor. Proteases and protease regulators that also activate specific cell surface receptors may serve to integrate coagulation with associated cellular responses required for tissue repair and growth, as well as to coordinate protease cascades and associated cellular responses in other systems, such as those involved in growth and remodeling of the nervous system.

Intracranial haemorrhage during exercise testing

We describe the occurrence of an intraparenchymal (thalamic) haemorrhage during a stress test in a hypertensive 52-year-old man who had suffered from myocardial infarction 3 months earlier. Common causes of spontaneous haemorrhage, such as arteriovenous malformation, aneurysms, neoplasm, bleeding disorders or vasculitis were excluded. This single neurological complication was observed from among 8000 exercise tests performed in our Institute from 1987 to 1993.

Nitroglycerin-induced penile erection and yawning in male rats: mechanism of action in the brain

The effect of the central administration of nitroglycerin, a potent organic nitrate vasodilator, on penile erection and yawning was studied in male rats. When given intracerebroventricularly (ICV), nitroglycerin (33-99 micrograms) induced the above responses dose-dependently. The minimal effective dose was 33 micrograms, which was active in 60% of the rats. Nitroglycerin (1.65-6.6 micrograms) induced penile erection and yawning also when injected in the paraventricular nucleus of the hypothalamus. Nitroglycerin responses were prevented by methylene blue (200-400 micrograms ICV), by d(CH2)5Tyr(Me)2-Orn8-vasotocin (0.5-1 micrograms ICV) but not hemoglobin (100-200 micrograms ICV). In contrast methylene blue (10-20 micrograms), d(CH2)5Tyr(Me)2-Orn8-vasotocin (0.05-0.1 microgram) and hemoglobin (10-20 micrograms) were ineffective when injected in the paraventricular nucleus. Systemic haloperidol (0.5-1 mg/kg IP) was also ineffective. The results suggest that nitroglycerin induces penile erection and yawning by activating brain oxytocinergic transmission through the formation of nitric oxide in the paraventricular nucleus of the hypothalamus.

Naturally occurring variation in bristle number and DNA polymorphisms at the scabrous locus of Drosophila melanogaster

The association between quantitative genetic variation in bristle number and molecular variation at a candidate neurogenic locus, scabrous, was examined in Drosophila melanogaster. Approximately 32 percent of the genetic variation in abdominal bristle number (21 percent for sternopleural bristle number) among 47 second chromosomes from a natural population was correlated with DNA sequence polymorphisms at this locus. Several polymorphic sites associated with large phenotypic effects occurred at intermediate frequency. Quantitative genetic variation in natural populations caused by alleles that have large effects at a few loci and that segregate at intermediate frequencies conflicts with the classical infinitesimal model of the genetic basis of quantitative variation.

Structure, expression, and activity of Tyro 3, a neural adhesion-related receptor tyrosine kinase

We have isolated mouse cDNA clones encoding Tyro 3, a receptor protein-tyrosine kinase (PTK) of the mammalin central nervous system (CNS). Expression of the Tyro 3 gene is strongly up-regulated in neurons of the mouse neocortex, cerebellum, and hippocampus after the day of birth, during periods of active synaptogenesis, and high expression is maintained in the adult CNS. The sequence of Tyro 3 cDNAs predicts a glycoprotein receptor with similarity to neural cell recognition and adhesion molecules--the extracellular (ligand binding) region of this receptor is composed of two immunoglobulin-related domains followed by two fibronectin type III repeats. Immunoblot and immunoprecipitation analyses with anti-Tyro 3 antibodies indicate that the 125 kD Tyro 3 protein is abundantly expressed in CNS synaptosomes, and immunohistochemical analysis of cultured hippocampal cells demonstrates that Tyro 3 is a product of neurons. Rat-2 fibroblasts stably transfected with a Tyro 3 expression construct acquire the ability to grow in soft agar, suggesting that Tyro 3 is potentially oncogenic.

Genetic applications of transposable elements in eukaryotes

Transposable elements have many potential applications in genetic research, including insertional mutagenesis, gene mapping, gene cloning, gene transfer within and between species, and identification of genes expressed in specific tissues at a particular time. All these genetic approaches are important in the study of molecular biology and evolution. As the number of known transposable element families increases and their properties are further documented, their utility as genetic research tools will become greater. The purpose of this article is to discuss the salient properties of transposable elements in eukaryotes and their applications to genetic research.

Structure and expression of the Tyro 10 receptor tyrosine kinase

We have isolated cDNA clones encoding Tyro 10, a novel receptor protein-tyrosine kinase (PTK) whose catalytic domain exhibits significant similarity to the Trk family of neurotrophin receptors (Lai & Lemke, 1991). We find that the Tyro 10 gene is widely expressed, both within and outside the nervous system, and in both developing and mature neural tissue. The primary structure of Tyro 10, deduced from cDNA sequence, defines a new sub-family of receptor PTKs. Although the Tyro 10 kinase domain is more closely related to the equivalent domains of Trk, TrkB and TrkC than to the catalytic domains of other receptor PTKs, it is less closely related to these Trk domains than they are to each other. More significantly, the Tyro 10 extracellular (ligand binding) domain is not structurally related to the extracellular domains of the Trk receptors, but instead bears homology to cell surface mediators of protein-protein interactions, including blood coagulation Factors V and VIII, and the neuronal recognition protein A5. These appear to be structural features of a distinct receptor PTK sub-family, in that they are also found in the recently-described discoidin domain receptor (DDR).

The human TYRO3 gene and pseudogene are located in chromosome 15q14-q25

Partial cDNAs of the human TYRO3 gene, encoding a putative receptor tyrosine kinase, and its processed pseudogene (TYRO3P) were cloned from human teratocarcinoma cell, bone marrow and melanocyte cDNA libraries. The tyrosine kinase homologous domains of TYRO3 and TYRO3P were sequenced and compared with each other and with the mouse TYRO3 gene. Abundant levels of the 4.2-kb TYRO3 mRNA were detected in human brain, and lower levels in other human tissues. TYRO3 and TYRO3P were both assigned to human chromosome 15q14-q25 by analysis of DNAs from somatic cell hybrids.

Novel and known protein tyrosine kinases and their abnormal expression in human melanoma

We have used the polymerase chain reaction and Northern blotting to identify protein tyrosine kinases that may play an important role in the process of melanoma initiation and progression. Degenerate primers from the conserved catalytic domain of tyrosine kinase genes were used to amplify and clone partial cDNA sequences from a human melanoma cell line (DX3-LT5.1) and normal human melanocytes. When the melanoma reaction products were sequenced, 13 distinct clones were found, of which one is novel to date and has provisionally been named MEK (for melanocytic kinase). Of the remaining 12 known kinases, only two, ERB-B2 and IGF1-R, have previously been reported in pigment cells. Reaction products from melanocytes included only eight of these 13 sequences. To test for quantitative differences in tyrosine kinase expression between normal and malignant cells, a panel of eight melanoma lines and normal melanocytes was analyzed by Northern blotting. Two tyrosine kinases (JTK-14/TIE and TYRO-9) were detected in some melanomas but were not found in normal melanocytes, whereas others, including MEK, appeared to be overexpressed in some malignant lines. A minority of kinases showed either no change or a reduction in the level of mRNA. Expression of tyrosine kinases varied independently, and individual lines contained various combinations of these enzymes. Our findings are consistent with an increased overall expression of these putative growth factor receptors during melanoma development.

Activin induces cell death in hepatocytes in vivo and in vitro

While studying endocrine responses to activin in female rats, we discovered that activin caused a marked reduction in liver mass. The regressed livers exhibited no gross signs of necrosis or infarction, but histopathological evaluation revealed extensive cell death in the centrilobular regions. The dying cells appeared to fragment into structures resembling apoptotic bodies. Liver mass and histological appearance were restored after cessation of activin infusion, indicating that on an organ level, this effect was reversible. To determine whether the effects observed in vivo were caused by direct actions on the liver, we then tested activin on isolated hepatocytes in serum-free medium. Under these conditions, activin caused many hepatocytes to undergo fragmentation, which was accompanied by a loss of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-reducing activity, an index of viability. We compared the effects of activin with those of transforming growth factor-beta because activin is structurally related to transforming growth factor-beta and because transforming growth factor-beta has been shown previously to induce cell death in hepatocytes. Both proteins caused cell death of comparable magnitude, as defined by the extent of loss of MTT-reducing activity, but transforming growth factor-beta was active at one tenth of the effective activin concentrations. A neutralizing monoclonal antibody to transforming growth factor-beta blocked the response to transforming growth factor-beta but had no effect on the response to activin. Conversely, follistatin, an activin-binding protein, blocked the response to activin but not to transforming growth factor-beta. Inhibin, which antagonizes the effects of activin in many systems, had little effect on the response to activin. Activin and transforming growth factor-beta differed in their onset of action; exposure to transforming growth factor-beta for only 1 hr induced a maximal response, whereas maximal response to activin required its continuous presence for 24 hr. These results show a novel effect of activin on cell death in hepatocytes in vivo and in vitro, suggesting that activin may have a previously unrecognized role in regulating hepatic function.

Mapping and characterization of P-element-induced mutations at quantitative trait loci in Drosophila melanogaster

X chromosomes derived from crosses of inbred P and M Drosophila melanogaster strains that had extreme effects on abdominal and/or sternopleural bristle number in males, were further analyzed to determine their effects in females and to map the loci at which the mutations occurred. Seven lines that had on average 3.9 fewer sternopleural bristles than wildtype in males had average homozygous sternopleural bristle effects of -2.2. The bristle effects were partially recessive, with an average degree of dominance of -0.60. Physical mapping of the sternopleural bristle effects of these lines placed them all at approximately 24.7 cM. These mutations are apparently allelic on the basis of a complementation test, and deficiency mapping indicates they occur within chromosomal bands 8A4; 8C6. In situ hybridization analysis of the sites of P element insertions of these lines suggests that mutations probably resulted from excision of P elements at 8C on the original inbred P strain chromosome. Two additional lines, NDC(19) and DP(146), had reduced numbers of sternopleural and abdominal bristles. NDC(19) males had 9.7 fewer abdominal and 8.6 fewer sternopleural bristles than wildtype. The corresponding homozygous abdominal and sternopleural bristle number effects were -5.8 and -3.8, respectively; with the abdominal bristle effect completely recessive and the sternopleural bristle effect nearly additive. DP(146) males had 6.2 fewer abdominal and 4.1 fewer sternopleural bristles than wildtype, with homozygous abdominal bristle effects of -4.3 and sternopleural bristle effects of -2.0. Abdominal bristle effects of this line were partially recessive whereas the sternopleural bristle effects were additive. Physical mapping showed effects on both bristle traits segregated jointly in these two lines, with the NDC(19) mutation closely linked to y and the DP(146) mutation 0.17 cM from it. Complementation tests and deficiency mapping also indicate the mutations in lines NDC(19) and DP(146) are at closely linked but separate loci within chromosomal bands 1B2; 1B4-6 and 1B4-6; 1B10 respectively, with some epistatic effects. In situ hybridization analysis of sites of P element insertion suggest that the NDC(19) mutation, which may be a scute allele, was probably caused by a P element insertion in the 1B region; the DP(146) mutation is also associated with an insertion at 1B.

[The effect of nifedipine in hypertensive cardiopathy. An echocardiographic and electrocardiographic study]

To assess whether antihypertensive therapy by nifedipine can reverse left ventricular (LV) hypertrophy, 15 hypertensive patients, mean age 47 years, were serially studied during 12 months of treatment with nifedipine in slow release (40-60 mg/day), by recordings of blood pressure (BP), ECG and echocardiogram. Blood pressure decreased from 161 +/- 6/104 +/- 3 mmHg to 131 +/- 3/89 +/- 1 mmHg, p < 0.001, and this fall first became statistically significant at 1 month. From the hemodynamic view point, BP decreased for a reduction in total peripheral resistance. The Sokolow-Lyon voltage decreased significantly after 6 months (from 33.5 +/- 2.7 to 28.1 +/- 2.1 mm, p < 0.01) without further changes in the subsequent months. Left ventricular mass, by echocardiography, decreased after 6 months (from 189 +/- 15 to 176 +/- 13 g/m2, p < 0.05) and further after 12 months (169 +/- 13 g/m2, p < 0.001). The reduction in LV mass was secondary to the decrease in wall thickness, particularly in posterior wall thickness. No significant changes were observed in LV fractional shortening throughout the study. Thus, nifedipine was an effective antihypertensive agent and reverted LV hypertrophy secondary to arterial hypertension without impairment of LV systolic function.

Effects of iron supplementation and discontinuation on serum copper, zinc, calcium, and magnesium levels in women

The purpose of this study was: 1) to establish the prevalence of depleted iron stores, iron deficiency, and low serum levels for copper, zinc, calcium, and magnesium in a healthy female population; and 2) to examine the effects of iron supplementation and discontinuation on the serum levels of the above minerals. One hundred eleven healthy women between the ages of 18 and 40 yr reported for fasted morning blood sampling for iron, copper, zinc, calcium, and magnesium status. Forty-five subjects were either iron-deficient as defined by a hemoglobin level below 120 g.l-1 (four subjects) or iron deplete as defined by a serum ferritin value below 20 micrograms.l-1 (43 subjects). Two subjects fit both criteria. This subgroup continued with the study and were prescribed a normal therapeutic iron dose (320 mg elemental iron per day, taken as two Slow-Fe tablets.d-1 for a period of 12 wk). The subjects then discontinued the iron supplementation for a further 12 wk. The response of the various blood minerals was monitored at 6-wk intervals. Twenty-five subjects completed the full 24-wk treatment. The main conclusions to be made from this study were that: 1) For this sample population of women, iron depletion was quite common (39%), although low hemoglobin values (< 120 g.l-1) were only seen in 3.6%. No subjects fell below the criteria for low serum copper levels (< 13.3 mumol.l-1) nor low serum magnesium levels (< 0.6 mmol.l-1). Seven subjects (6.5%) fell below the criteria for low serum zinc levels (< 11.5 mumol.l-1) while two subjects (1.8%) were below the criteria for low serum calcium levels (< 2.20 mmol.l-1). 2) Therapeutic oral iron supplementation was successful in raising mean serum ferritin values from 15.9 micrograms.l-1 to 36.5 micrograms.l-1 but was not associated with decrements in serum copper or calcium levels. 3) The treatment did not significantly effect serum zinc and magnesium levels during the supplementation period, but a downward trend continued through the discontinuation phase so that at 18 and 24 wk serum zinc and magnesium levels were significantly lower than baseline. 4) Oral contraceptive use was associated with elevated serum copper and ferritin values and lowered serum magnesium levels.

Haemodialysis as a model for studying endogenous plasma DNA: oligonucleosome-like structure and clearance

The rate of clearance of extracellular plasma DNA in man has important implications for pathogenetic mechanisms in systemic lupus erythematosus (SLE), as well as for certain other clinical states. Present knowledge of this parameter is derived exclusively from studies of injected, naked DNA in animals. Recent information indicates that the physiologic form of plasma DNA in SLE is that of oligonucleosome-like molecules rather than of naked DNA and consists of multimeric complexes of DNA bound to histone, probably arising from an apoptotic process. In order to study the rate at which these oligonucleosome-like complexes are removed from plasma and to do so in man rather than experimental animals, we exploited the observation that during haemodialysis large amounts of DNA are released, apparently within the dialysis coil, into the patient's plasma. Since this release appears to cease promptly with termination of the procedure, it offered the potential for estimating the rate of removal of such DNA from human plasma. Moreover, if that DNA, as postulated, were shown to possess an oligonucleosome-like structure resembling that found endogenously in human SLE, the relevance of such information to the human disease state would be further enhanced. The present results support the conclusion that DNA released into plasma during haemodialysis possesses such an oligonucleosome-like structure. The plasma half-life of that DNA in man was found not to exceed 4 min. The highly dynamic state thus implied for extracellular endogenous plasma DNA in man has important implications for pathogenetic mechanisms dependent on dsDNA in SLE. Moreover, individuals undergoing chronic haemodialysis, who are thereby exposed to a very large cumulative amount of such DNA, might serve as models for studying its long-term sequelae.

[The effect of nifedipine on arterial pressure and exercise tolerance in hypertensive patients]

The aim of this research was to assess whether the antihypertensive therapy with nifedipine, a dihydropyridine calcium-antagonist, is able to control hypertension not only at rest but also during exercise. So, 20 male hypertensive patients, mean age 48 years, were evaluated by symptom limited bicycle exercise (10 W/min) before and after 6 and 12 months of therapy with nifedipine in a slow releasing form (40-60 mg/day). Exercise tolerance significantly increased after 12 months of antihypertensive therapy with nifedipine (from 146 +/- 5 to 153 +/- 4 W, p < 0.05). Systolic and diastolic blood pressure decreased after 6 and 12 months both at rest (from 160 +/- 6/109 +/- 9 mmHg to 132 +/- 3/91 +/- 3 and 135 +/- 4/93 +/- 1 mmHg, respectively, both p < 0.001) and during exercise (at end exercise: from 238 +/- 7/121 +/- 5 mmHg to 216 +/- 6/106 +/- 3 and 213 +/- 6/107 +/- 3 mmHg, respectively, both p < 0.001). No significant changes in heart rate were observed during antihypertensive therapy both at rest and during exercise test. In conclusion, long-term antihypertensive therapy with nifedipine was effective in the control of hypertension both at rest and during physical stress. Moreover, an improvement in effort tolerance was observed in hypertensive patients.

The role of the pericardium in conditioning the effects of physical training

More work needs to be done on the extent to which the pericardium can modulate the cardiovascular response to exercise and the mechanisms whereby this modulation is brought about. Studies are needed to differentiate the effects of the pericardium on the cardiovascular exercise response, comparing trained with untrained subjects. Evidence is accumulating that exercise training in patients with heart failure improves not only the performance of exercising muscles, but also has some beneficial effects on central hemodynamics. The extent to which these beneficial effects can be attributed to conditioning the pericardium remains speculative.

[What have we learned from large trials?]

Clinical trials, during myocardial infarction, showed the importance of thrombolytic therapy on coronary patency, to improve left ventricular function, to reduce early and late mortality. Since the efficacy of thrombolytic therapy is now well established, most clinical trials were made to compare the efficacy of SK, rt-PA and APSAC and to evaluate concomitant drugs. Recanalization and coronary patency, reocclusion and incidence of side effects, left ventricle function's improvement and lowered mortality have been used to assess drugs' activity. At the moment the efficacy of three thrombolytic drugs seems to be the same. So the drug's choice is related not to drug's efficacy but to side effects of the drugs. Concomitant intravenous heparin therapy is now under study; utility of this therapy is shown by its theoretical assumptions and by clinical trials results. Large clinical trials are working to extend our knowledge, improving the patients' management in our every day clinical practice. Furthermore, large trials do not replace but go together with studies performed on few patients, whose results often give advance notice of those of large ones.

[A new anti-ischemic drug for the treatment of stable effort angina pectoris: nicorandil. Comparison with placebo and isosorbide-5-mononitrate]

The aim of this study was to investigate antianginal and antiischemic activity and tolerance of a new nitrate derivative, nicorandil (N). This research has been carried out in 18 patients, aged 47-70 years, suffering from stable effort angina with fixed ischemic threshold. The study started with 10 days of washout, during which the patients exercised twice on bicycle to verify the reproducibility of the test. Then, they took N or isosorbide-5-mononitrate (ISM) for 14 days according to a double blinded cross-over balanced study. Between the 2 periods patients took placebo (PL) for 14 days. In the first day and in the last day of each period, 2 hours after the last drug intake, patients performed a stress test on bicycle. Like ISM, N significantly increased, versus PL, 1 mm of ST depression time (ischemic threshold) in the first and in the last day, without differences between the 2 drugs and between the days. Moreover, ST depression was significantly lower at maximal common work (MCW) versus PL. The rate-pressure product was not different from PL after N and ISM at maximal common work, but is was increased at the ischemic threshold. In conclusion, like ISM, N has shown antiischemic activity in patients suffering from stable angina pectoris on effort with fixed ischemic threshold. After 14 days of treatment there was no evidence of tolerance. The activity of N seems essentially due to an increase of coronary blood flow to ischemic zones.

[Transdermal nitroglycerin in stable effort angina. I. Therapeutic effect and duration of the action of a single dose. Comparison with placebo and isosorbide dinitrate]

To assess the efficacy of 2 doses of a transdermal system for nitroglycerin, 10 and 20 mg (NTTS 10 and NTTS 20) and isosorbide dinitrate 40 mg (ISD 40) on exercise tolerance test, a double-blind within patients placebo (PL) controlled study was performed: 12 male patients, aged 47-71 years, with stable effort angina, with fixed ischemic threshold, received, according to a 4 x 4 latin square design, NTTS 10, NTTS 20, ISD 40 and PL, at 7.00 am on 4 consecutive days. Bicycle exercise tests were performed 4 and 12 hours post-dosing, after which the systems were removed. NTTS 10 and 20 and ISD 40 increased significantly ischemic threshold, anginal threshold and decreased maximal ST depression at the fourth hour. Only NTTS 10 and NTTS 20 showed antiischemic activity after 12 hours. During exercise, at the fourth and twelfth hour, there was no significant difference in rate-pressure product between placebo and NTTS 10 and 20 and ISD 40. Therefore the antiischemic activity of these drugs was not related to a decrease of myocardial oxygen consumption. In conclusion, in comparison with PL, NTTS 10, 20 and ISD 40 had antiischemic and antianginal activity at the fourth hour, while at the twelfth hour this activity was observed only after NTTS 10 and 20, without differences between the 2 doses.

[Transdermal nitroglycerin in stable effort angina. II. Administration of continuous high doses and alternate high-low doses. Absence of tolerance]

Aim of this study was to evaluate the efficacy of 2 different schedules of nitroglycerin (N), given by means of transdermal therapeutic system (TTS): continuous (20 mg patch at 8.00 am and at 8.00 pm NTTS/c) and high/low doses therapy (20 mg patch at 8.00 am and 10 mg at 8.00 pm NTTS/a), respectively. Eighteen volunteers, gave informed, written consent; male patients, aged 57 +/- 2 years, with stable effort angina pectoris, were randomly given, in double-blind condition, NTTS/c, NTTS/a or placebo (PL), each for 1 week period, according to a 3 x 3 latin square design. Bicycle exercise tests were performed on the first and on the last day of each period of the study, 12 hours after the last patch. NTTS/c and NTTS/a increased ischemic threshold and decreased the ischemic depression ST at maximal common work, compared to placebo, without differences between tests performed at 1 and 7 day. In conclusion, NTTS/a showed antiischemic activity after 7 days, so no tolerance was observed in those patients.

Assessment of Package Integrity Using a Spray Cabinet Technique

A novel spray cabinet technique was developed to determine the microbial integrity of aseptically filled juice packages as an alternative to immersion techniques. The spray cabinet was constructed to include two pumps and 32 nozzles to achieve complete coverage over all surfaces of the test packages. A cell culture of Lactobacillus cellobiosus was sprayed onto the packages during testing. Standard pinhole orifices were used to determine the efficiency of the spray cabinet technique, 10-μm holes and 5-μm holes were detectable after 15 and 30 min of spraying, respectively. Aseptically filled juice packages were subjected to an abusive handling procedure designed to create package defects in order to compare package integrity by the spray cabinet technique and an immersion method. The spray cabinet technique provided better detectability than the immersion method.

An extended family of protein-tyrosine kinase genes differentially expressed in the vertebrate nervous system

We have used PCR to identify 13 novel protein-tyrosine kinase genes (tyro-1 to -13), six of which (tyro-1 to -6) are preferentially expressed in the developing vertebrate nervous system. The tyro-2 and tyro-9 genes encode kinase domains that exhibit strong amino acid sequence similarity to the equivalent regions of the receptors for EGF and FGF, respectively, and may encode novel receptors for these or related polypeptide ligands. The tyro-1 to -6 genes are all expressed during central nervous system neurogenesis and exhibit distinct and highly regionalized patterns of expression in the adult brain. Together with recent studies in invertebrates, these data are consistent with the hypothesis that protein-tyrosine kinases play a central role in neural development.

Bone-inducing activity of mature BMP-2b produced from a hybrid BMP-2a/2b precursor

The human osteoinductive proteins BMP-2a and BMP-2b have been cloned and expressed in mammalian cells. In order to improve expression levels we examined the role of the proregion in assembly and export. Use of the BMP-2a proregion combined with the mature region of BMP-2b leads to dramatically improved expression of mature BMP-2b. Mature BMP-2b has been purified to near homogeneity from the BMP-2a/2b hybrid, and its structural properties and biological activity determined. Recombinant mature BMP-2b homodimer elicits bone formation in vivo.

[Effects of indenolol on left ventricular mass in patients with essential arterial hypertension]

This study evaluated the effect of long-term antihypertensive therapy with indenolol, a beta blocking agent with beta 2 stimulating activity, its antihypertensive hemodynamic mechanism and its effect on hypertensive left ventricular (LV) hypertrophy. Fourteen hypertensive patients, mean age of 48 years, were serially studied during 12- month therapy with indenolol (60-120 mg daily), by recording blood pressure, electrocardiogram and echocardiogram. Blood pressure, heart rate and cardiac output significantly decreased after 1 months of therapy, LV posterior wall thickness decreased after 6 months, interventricular septum thickness and LV mass decreased after 12 months. LV fractional shortening did not change throughout the study. Blood pressure normalized (less than or equal to 140/90 mmHg) in 50% of the patients; LV mass normalized in 40% of the patients. In conclusion, indenolol was an effective antihypertensive agent, also in the long-term treatment. Its antihypertensive hemodynamic effect seems to be due mainly to a reduction in cardiac output. Indenolol caused a regression of LV hypertensive hypertrophy without impairment of LV systolic function.

[A case of left internal capsular infarction with auditory hallucination and peculiar amnesia and dysgraphia]

A 46-year-old businessman suddenly became to behave curiously on the morning, September 1, 1988. He forgot how to go through an automatic ticket gate, which he used every day. In his company, he also forgot how to open the cash box, and he wrote a meaningless report for his business. From the night on that day, he had experienced auditory hallucination in which whispering words of some criticism to his performance for a few days. On the next day, he was admitted to a psychiatric hospital because he was suggested to have schizophrenia. By day 6 after the onset, his curious symptoms completely disappeared. However, slight verbal memory disturbance and cognitive dysfunction still remained. Because the brain CT on day 6 showed a small localized subcortical infarction in the left hemisphere he was transferred to our clinic on day 20 to elucidate the relation between the abnormal behavior and the infarction. His blood pressure was 116/64 mmHg and pulse was regular 63/min. He was clear and did not have any neurological deficit. He kept his episodic memory regarding the events at the onset and could almost recall them precisely. Results of standard blood tests, electrocardiogram, ultrasound cardiogram, electroencephalogram as well as cerebral angiography were normal. Computed tomography and magnetic resonance imaging showed an infarcted lesion in the genu of the left caudate nucleus, adjacent to the anterior part of the thalamus.(ABSTRACT TRUNCATED AT 250 WORDS)

Propionyl carnitine in stable effort angina

The aim of this study was to investigate the anti-ischemic activity of propionyl carnitine (PC) in 18 informed, volunteer male patients, aged 37-70, suffering from a typical stable effort angina. The study design was randomized, balanced, crossover, and double blinded. The study lasted 75 days. In the first 15 days of washout the patients performed two maximal symptom-limited bicycle tests to verify the repeatability of the parameters examined. Then one group received PC for 30 days 500 mg three times a day, and the other group received placebo (PL) three times a day. At the end of 30 days the groups exchanged treatments. At the end of each period, 2 hours after the last oral administration, the patients performed a maximal symptom-limited bicycle exercise test with increased loads of 10 watts/min. No significant differences were observed between the two tests performed during the wash-out period, for a 1 mm ST-segment depression time, for the time to the end of exercise, and for the rate x pressure product at the same experimental time. The oral administration of PC in coronary patients increased both the 1 mm ST-segment depression time and the time to the end of exercise. Furthermore, the drug reduced the ischemic depression of ST at maximal common work and at maximal work. After PC, the rate x pressure product was not significantly different in relation to placebo at submaximal and maximal exercise. Thus PC seems to have an antiischemiclike effect, probably related to its metabolic activity.

Ofloxacin treatment of nongonococcal urethritis. A multi-center study in Asia

Ofloxacin, a new quinolone antibacterial agent, is active in vitro against gonococcal and nongonococcal urogenital pathogens. Chlamydia trachomatis infection is the most common cause of nongonococcal urethritis. In a multicenter study in seven Asian countries, 105 mal patients with chlamydial urethritis and 46 male patients with nongonococcal and nonchlamydial urethritis were treated with oral ofloxacin at a dosage of 200 mg twice daily for 5 to 10 days. The evaluation performed at day 5 and/or day 10 after treatment revealed good results in 58.2% and 96.8% of the chlamydial urethritis group, and 73.1% and 79.4% of the nongonococcal, nonchlamydial urethritis group, respectively. No severe side effects were observed. Ten-day treatment with ofloxacin showed good clinical efficacy on nongonococcal urethritis.