Impaired synergistic activation of stress-activated protein kinase SAPK/JNK in mouse embryonic stem cells lacking SEK1/MKK4: different contribution of SEK2/MKK7 isoforms to the synergistic activation

Stress-activated protein kinase/c-Jun NH(2)-terminal kinase (SAPK/JNK), which is a member of the mitogen-activated protein kinase (MAPK) family, plays an important role in a stress-induced signaling cascade. SAPK/JNK activation requires the phosphorylation of Thr and Tyr residues in its Thr-Pro-Tyr motif, and SEK1 (MKK4) and MKK7 (SEK2) have been identified as the upstream MAPK kinases. Here we examined the activation and phosphorylation sites of SAPK/JNK and differentiated the contribution of SEK1 and MKK7alpha1, -gamma1, and -gamma2 isoforms to the MAPK activation. In SEK1-deficient mouse embryonic stem cells, stress-induced SAPK/JNK activation was markedly impaired, and this defect was accompanied with a decreased level of the Tyr phosphorylation. Analysis in HeLa cells co-transfected with the two MAPK kinases revealed that the Thr and Tyr of SAPK/JNK were independently phosphorylated in response to heat shock by MKK7gamma1 and SEK1, respectively. However, MKK7alpha1 failed to phosphorylate the Thr of SAPK/JNK unless its Tyr residue was phosphorylated by SEK1. In contrast, MKK7gamma2 had the ability to phosphorylate both Thr and Tyr residues. In all cases, the dual phosphorylation of the Thr and Tyr residues was essentially required for the full activation of SAPK/JNK. These data provide the first evidence that synergistic activation of SAPK/JNK requires both phosphorylation at the Thr and Tyr residues in living cells and that the preference for the Thr and Tyr phosphorylation was different among the members of MAPK kinases.

Cloning of androgen-inducible gene 1 (AIG1) from human dermal papilla cells

Cultured human dermal papilla cells are useful for studying the androgen-dependent growth of hair follicles. We cloned the human homolog of FAR-17a, a gene identified from the hamster flank organ as one of the androgen inducible genes, by degenerative PCR and human dermal papilla cDNA library screening. We isolated a novel cDNA clone, designated as AIG1 (Androgen-inducible Gene 1), whose expression was found to be inducible by androgen. AIG1 cDNA consists of 1,398 nucleotides in length, which encodes a protein of 238 amino acids (27 kDa). The deduced protein sequence showed 35% overall homology with FAR-17a. RT-PCR of human dermal papilla cDNA revealed two mRNA transcripts, which differed by 156 nucleotides. This results in an in-frame deletion of 52 amino acids. A computer analysis of hydropathy indicated five hydrophobic domains are present in the large protein sequence, while four hydrophobic portions are in the smaller protein sequence. In a Northern blot analysis, the major 1.5 kb and minor 1.2 kb bands of AIG1 mRNA were detected. AIG1 mRNA was expressed at a relatively high level in the heart, ovary, testis, liver, and kidney. However, they were expressed at a low level in the spleen, prostate, brain, skeletal muscle, pancreas, small intestine, and colon. When dermal sheath cells were stimulated with DHT, the level of AIG1 mRNA expression was increased at 30 ng/ml. The level of expression was higher in males than females. In this study, we cloned and initially characterized AIG1. Further study will be needed to understand the functions of AIG1 in the androgen-regulated hair cycle.

Effects of nicotine on APP secretion and Abeta- or CT(105)-induced toxicity

Several lines of evidence indicated that overexpression or aberrant processing of amyloid precursor protein (APP) is causally related to Alzheimer's disease (AD). Amyloid precursor protein is principally cleaved within the amyloid beta protein domain to release a large soluble ectodomain (APPs), known to have a wide range of trophic functions. The central hypothesis guiding this review is that nicotine may play an important role in APP secretion and protection against toxicity induced by APP metabolic fragments (beta-amyloid [Abeta], carboxyl terminal [CT]). Findings from our experiments have shown that nicotine enhances the release of APPs, which has neurotrophic and neuroprotective activities in concentration-dependent (>50 micromol/L) and time-dependent (>2 hours) manners. In addition, pretreatment of nicotine (>10 micromol/L for 24 hours) partially prevented Abeta or CT(105)-induced cytotoxicity in primary cultured neuron cells, and the effects of nicotine-induced protection were inhibited by the pretreatment with a nicotine alpha-bungarotoxin. Nicotine (>10 micromol/L for 24 hours) partially inhibited CT(105)-induced cytotoxicity when PC12 cells was transfected with CT(105). From these results, we proposed that nicotine or nicotinic receptor agonist treatment might improve the cognitive functions not only by supplementation of cholinergic neurotransmission, but also by protecting Abeta- or CT(105)-induced neurotoxicity probably through the increased release of APPs and the activation of nicotinic receptors.

Identification of novel genes differentially expressed in PMA-induced HL-60 cells using cDNA microarrays

Identification of normal growth and differentiation-inducing proteins and their interaction in normal development have made it possible to elucidate the molecular basis of normal development and the mechanisms uncoupling growth and differentiation during tumor development. The development of cancer and the experimental reversal of tumorigenicity are accompanied by complex changes in patterns of gene expression. cDNA microarrays provide a powerful tool for studying these phenomena. In the present study, a high-density microarray of human cDNA elements was used to search for differences in gene expression associated with differentiation of human promyelic leukemia HL-60 cells. Microarrays containing 3,063 human cDNAs were printed on glass slides with high-speed robotics. These DNA 'chips' were used to quantitatively monitor differential expression of the cognate human genes using a highly sensitive two-color hybridization assay. The identification of known and novel phorbol ester-regulated genes in hematopoietic progenitor cells demonstrates the sensitivity of the assay.

Features for a B-ISDN telemedicine system and its application

Telemedicine technology is emerging as a new way of medical practice. It will provide more cooperative activity between departments and more comfortable access for disabled patients home. We developed two types of telemedicine system: a telediagnosis system and a home care system. Our telemedicine application is aimed to be run on the broadband-integrated services digital network (B-ISDN). The legacy network is also considered. The user interface is designed to help doctors to communicate easily. The key elements of telemedicine systems are user friendly interface, medical multimedia database design highly refined display technique.

The nuclei innervating digastric muscle do not project to the hypoglossal nucleus in the rat

We employed the retrograde neural tracing method using the pseudorabies virus bartha strain (PRV-Ba) to investigate the projection from accessory trigeminal nucleus (Acc5) or accessary facial nucleus (Acc7) to hypoglossal nucleus (HP). After injection of PRV-Ba into the bellies of the digastric muscle, the PRV-Ba containing neurones were observed in Acc5 of the cranial belly injected rats and Acc7 of caudal belly injected rats ipsilaterally, but not in HP. These results suggest that Acc5 and Acc7 may not project to HP and that movements of the digastric muscle are not related to cooperation with tongue movements during mastication.

The coexistence of calcitonin gene-related peptide and substance P in pericellular arborization and satellite cell of goat trigeminal and nodose ganglia

Pericellular arborization is reported to be the self-regulating structure in sensory ganglia. Although the calcitonin gene-related peptide (CGRP) or substance P (SP) immunoreactive pericellular arborization appeared in the sensory ganglia, there was no available information that CGRP and SP colocalize in this structure. As the attempts to resolve the question described above, the present study was undertaken to identify the coexistence of CGRP and SP in pericellular arborizations of the goat nodose and trigeminal ganglia by double immunohistochemistry. As the results show, CGRP immunoreactivity was present in every pericellular arborization containing SP immunoreactivity in trigeminal ganglia, however, pericellular network containing CGRP or SP immunoreactivity was not present in nodose ganglia. Unexpectedly, a few small satellite elements were observed to contain intense CGRP and SP immunoreactivity at the periphery of CGRP and SP immunoreactive neurones in nodose ganglia. Therefore, these results suggest that CGRP and SP coexist in pericellular arborizations, and that satellite cell as well as pericellular arborization may be involved in intraganglionic regulation of goat sensory ganglia.

Are substance P neurons of the paraventricular nucleus related to the osmotic regulation in the Mongolian gerbil?

In recent years, the gerbil has been used as an experimental animal for study osmotic regulation, because of its inherent high degree of water re-uptake in kidney. Many evidences to explain this characteristic accumulated on the kidney level, it do not, however, manifest what concerns on hypothalmo-hypophyseal level. In this study, we have focused on the difference between the colchicine treated gerbil and rat in distributions of substance P (SP), which is known to have antidiuretic property. Unlike rat, in which a few SP+ neuron is present, SP+ neurons were abundantly observed in the paraventricular nucleus (PVN) of the gerbil. Furthermore SP+ cells in PVN were manifested in dehydrated gerbils, in spite of non-colchicine treatment. Therefore, we suggest that the abundant SP+ neurons in PVN may be a clue to address the neuroendocrinal mechanism concerning the high degree of osmotic regulation in this animal.

The distribution of calcitonin gene-related peptide in gastric vagal circuit of rats

In the present study, we performed the retrograde tracing method using the neurotropic pseudorabies virus bartha strain (PRV-Ba) and immunohistochemistry against CGRP, to identify whether CGRP exists in the gastric monosynaptic vagal circuit between dorsal motor nucleus of vagus nerve (DMV) and nucleus tractus solitarius (NTS). At the results, PRV immunoreactive neurons were found in both DMV and NTS. However, CGRP-immunoreactive cells were present only in NTS, which contained no double-labeled neurons for PRV and CGRP. These results suggest that CGRP may not have a neuronal function in gastric vagal circuit of rat.

The existence of substance P in Purkinje cells in cerebellum of the gerbil

We performed this study to identify the characteristics of substance P localization in gerbil cerebellum by immunohistochemistry. Substance P immunoreactivity was present in Purkinje cells of cerebellar cortex but not in other structures. It is suggested that the cerebellar mechanism of gerbil may be different from that of other species.

Prognostic factors for short-term survival in alcoholic hepatitis in Japan: analysis by logistic regression

Prognostic factors for the outcome of patients with alcoholic hepatitis were identified by logistic regression analysis. To predict the outcome immediately after admission, clinical data from 97 patients with alcoholic hepatitis on admission were introduced to multivariate analysis. Independent prognostic factors for favorable outcome were hepaplastin time, peripheral white blood cell count, age (40 to 60 years), and serum creatinine level (below 1.4 mg/dl). Sensitivity, specificity, positive predictive value, negative predictive value, and predictive accuracy were 0.78, 0.89, 0.78, 0.89, and 0.86, respectively. The resultant equation for the death rate was applied to another set of patients with alcoholic hepatitis as a validation study. Predictive accuracy estimated 0.95 in validation. The prognostic index derived was simple, accurate, and useful in the prediction of the outcome in patients with alcoholic hepatitis. Furthermore, it provides the clinician with an indication of the necessity for the intensive care of patients in a critical condition.

Ontogeny of amino acid transport system A in rat placenta

Amino acid transport System A has previously been demonstrated in apical membranes derived from rat placenta, as well as in apical and basal membranes derived from human placenta. We have studied Na(+)-dependent alpha-(methylamino)isobutyric acid (MeAIB) transport in apical and basal predominant membrane fractions prepared from 14 and 20 day gestation rat placenta. Marker enzyme recoveries did not differ significantly between age groups. Markers for intracellular organelles were also found to be comparable. Na(+)-dependent MeAIB transport was not sensitive to freezing and could be found in all membrane components tested. Kinetic parameters were studied--Km = 852 +/- 215 microM, Vmax = 718 +/- 126 pmol/5 sec/mg protein--20 day apical; Km = 748 +/- 269 microM, Vmax = 610 +/- 176 pmol/5 sec/mg protein--20 day basal-predominant; Km 614 +/- 261 microM, Vmax = 123 +/- 45 pmol/5 sec/mg protein-14 day apical. Kinetic parameters could not be determined in the 14 day gestation basal-predominant fraction because of the small amount of uptake present. We conclude that System A like activity is found in both apical and basal predominant membrane fractions derived from rat placenta, and that this activity increases over the last one third of gestation.

Two forms of phospholipase C-beta 1 generated by alternative splicing

Phospholipase C-beta 1 (PLC-beta 1) exists as two immunologically indistinguishable polypeptides of 150 and 140 kDa and is encoded in rat brain by two distinct transcripts of 5.4 and 7.2 kilobases (kb). cDNA corresponding to the entire 5.4-kb transcript as reported previously reveals an open reading frame that is capable of coding a 1216-amino acid polypeptide (Suh, P. G., Ryu, S. H., Moon, K. H., Suh, H. W., and Rhee, S. G. (1988) Cell 54, 161-169). We have now isolated cDNAs corresponding to the entire 7.2-kb transcript from a rat brain cDNA library. The 7.2-kb transcript differs from the previously reported 5.4-kb transcript by possessing both an additional 118 nucleotides located near the end of the coding sequence and a 1738-nucleotide extension of the 3'-flanking region. The presence of the 118-nucleotide insert in the cumulative 7.2-kb sequence gives rise to an open reading frame that is capable of coding a 1173-amino acid polypeptide (PLC-beta 1b), the carboxyl-terminal sequence of which differs from that of the 1216-amino acid polypeptide (PLC-beta 1a) derived from the 5.4-kb transcript. Antibodies were raised against synthetic peptides corresponding to the carboxyl-terminal portions of PLC-beta 1a and PLC-beta 1b. Immunoblot analysis with these isozyme-specific antibodies revealed that both PLC-beta 1a and PLC-beta 1b are expressed in rat brain and C6Bu-1 glioma cells and that PLC-beta 1a and PLC-beta 1b correspond to the previously identified 150- and 140-kDa PLC-beta 1 enzymes, respectively. Analysis of PLC-beta 1 genomic DNA indicates that PLC-beta 1a and PLC-beta 1b are derived from a single gene by alternative RNA splicing.

Role of serum interleukin-8 and intercellular adhesion molecule-1 in the severity of alcoholic hepatitis

Among patients with alcoholic hepatitis, three groups were distinguished by histological findings and clinico-pathological features. The aim of this study was to clarify the role of soluble intercellular adhesion molecule-1 (sICAM-1) and interleukin-8 (IL-8) in the development of severe alcoholic hepatitis. The levels of sICAM-1 and IL-8 were well correlated with the severity of liver injuries. The concentrations of serum IL-8 were significantly correlated with the number of polymorphonuclear leukocytes infiltrating the liver. Serial determination of these two markers revealed that IL-8 may be complementary in assessing the severity and prognosis of alcoholic hepatitis.

Purification of a novel phospholipase C isozyme from bovine cerebellum

An isozyme of phosphoinositide-specific phospholipase C (PLC) was purified to near homogeneity from bovine cerebellum by a combination of several column chromatography procedures. Approximately 80 micrograms of pure enzyme were obtained from 4 kg of bovine cerebellum, with a final specific activity of 7.5 mumol/min/mg protein in the presence of 0.1% deoxycholate. The enzyme is specific for phosphatidylinositol and phosphatidylinositol 4,5-bisphosphate but does not hydrolyze phosphatidylcholine. The molecular weight of the enzyme determined by SDS-polyacrylamide gel electrophoresis is approximately 97,000. Polyclonal antibodies to previously characterized PLC isozymes, PLC-beta 1, -beta 2, -gamma 1, -gamma 2, and - delta 1, did not cross-react with the purified cerebellar enzyme. Moreover, polyclonal antibodies prepared against the cerebellar enzyme did not react with purified PLC-beta 1, -beta 2, -gamma 1, -gamma 2, or -delta 1. However, the cerebellar enzyme was recognized by two antibodies generated against peptide sequences common to mammalian PLC isozymes. Comparison of partial amino acid sequences of the purified cerebellar enzyme with the deduced amino acid sequence of each known PLC isozyme shows that the cerebellar enzyme is a novel PLC, which could be classified as a PLC-beta-type isozyme. Thus, we have designated this enzyme PLC-beta 4.

Pitch diversity in alpha-helical coiled coils

Two complementary methods for measuring local pitch based on heptad position in alpha-helical coiled coils are described and applied to six crystal structures. The results reveal a diversity of pitch values: two-stranded coiled coils appear to have pitch values near 150 A; the values for three- and four-stranded coiled coils range closer to 200 A. The methods also provide a rapid and sensitive gauge of local coiled-coil conformation. Polar or charged residues in the apolar interface between coiled-coil helices markedly affect local pitch values, suggesting a connection between pitch uniformity and coiled-coil stability. Moreover, the identification of a skip residue (heptad frame shift) in the hemagglutinin glycoprotein of influenza virus (HA) allows interpretation of local pitch changes. These results on relatively short coiled-coil structures have relevance for the much longer fibrous proteins (many of which have skip residues) whose detailed structures are not yet established. We also show that local pitch values from molecular dynamics predictions of the GCN4 leucine zipper are in striking agreement with the high-resolution crystal structure--a result not readily discerned by direct comparison of atomic coordinates. Taken together, these methods reveal specific aspects of coiled-coil structure which may escape detection by global analyses of pitch.

Intestinal morphometry and bile acid-induced mucosal injury in chronic experimental renal failure

To examine whether the intestinal mucosa in uremia is more prone to injury, we studied acute intestinal mucosal injury in rats with experimental chronic renal failure (RF) and sham-operated and starved control animals. Intestinal injury was produced by perfusing intestinal segments in vivo with 5 mmol/L chenodeoxycholic acid. Histologic specimens were then taken from the proximal and distal perfused and unperfused intestinal segments. Quantitative morphometry was done with computerized image analysis, and samples of the unperfused intestine were assayed for protein and DNA content. Chronic RF did not significantly affect the functional or morphologic injury caused by chenodeoxycholic acid. However, it was noted that RF rats had consistently taller villi and deeper crypts in all the samples studied. The protein content and the ratio of DNA to protein was similar among the three groups. The mechanism of the increase in villus height and crypt depth in the RF rats was not related to increases in tissue water content or to alterations in protein or DNA content, and the mechanism thus remains unexplained. This study clearly demonstrates, however, that the intestinal mucosa of rats with chronic renal insufficiency is not more susceptible to mucosal injury by bile acids than is the mucosa of appropriate control animals.

Effects of concentration of local anaesthetic drugs in extradural block

An increase in the concentration of bupivacaine from 0.5% to 0.75% and etidocaine from 1.0% to 1.5% for extradural block resulted in a more rapid onset of sensory analgesia and motor blockade, a greater frequency of adequate analgesia,a greater depth of motor block and a longer duration of sensory analgesia and motor blockade. An increase in the concentration of prilocaine from 2% to 3% failed to reveal any significant advantage. The use of the more concentrated solutions of bupivacaine and etidocaine would appear to afford significant clinical advantages in extradural anaesthesia for surgery.