Increased tyrosine kinase activity of c-Src during calcium-induced keratinocyte differentiation

In cultured human epidermal keratinocytes, induction of differentiation by Ca2+ and ionophore treatment was found to result in rapid elevation of c-Src tyrosine kinase activity and inactivation of the c-Yes tyrosine kinase. Activation of c-Src kinase was accompanied by tyrosine dephosphorylation, which might be explained by a rapid increase in intracellular protein-tyrosine phosphatase activity. Ca(2+)-induced differentiation was also associated with altered tyrosine phosphorylation of several cellular proteins and correlated with a marked redistribution of intracellular phosphotyrosine from membrane and adhesion sites to the nucleus. Some of the c-Src protein was also found in the nucleus after Ca2+ treatment, and Ca(2+)-activated c-Src bound to three cellular proteins (120 kDa, 65 kDa, and 34 kDa). In agreement with these results, immunohistochemistry on human epidermis revealed an increase in c-Src expression and tyrosine phosphorylation in cells undergoing differentiation, which strongly suggests a possible role of non-receptor tyrosine kinases in epithelial cell maturation.

[ELISA of serum isoferritin and its clinical application]

Serum isoferritin levels were detected by ELISA in 96 normal, 11 cases of hepatocellular carcinoma (HCC), 28 breast cancer (BC), 31 lung cancer (LC), 26 breast fibroma, 11 pneumonia and 11 tuberculosis. The results reveal significant differences of serum isoferritin levels between the normals and the patients, and between the malignant cases and benign cases (P < 0.01). Serum isoferritin demonstrates higher sensitivity in detecting HCC, LC and BC and thus is of great value in the differential diagnosis of these cancers.

[Study on casting precision of plat castable ceramic crowns]

The plat castable ceramic crown was made with investment material prepared in our college with our own casting technique by a Chinese-made casting machine. The accuracy and fitness of the crown were studied and appraised. Results show that the margin of fitness is 46 microns and that the cement film thickness of the dies in the spacer material group is 65.13 microns. Hence the results are satisfactory. The Plat castable ceramic crown might be used in clinical dentistry.

Jones matrix for round-trip wave propagation in nonreciprocal media

Using a communication channel model, we prove the known theorem that the Jones matrix of a system for backward propagation is the transpose of that for forward propagation. This result, together with the transformation of a coordinate system for opposite propagation directions, is shown to be useful for analyzing the round-trip wave propagation in nonreciprocal media.

New Eremophilane Type Lactones from the Roots of Ligularia veitchiana

Phytochemical investigation of the roots of LIGULARIA VEITCHIANA has resulted in the characterization of two new eremophilanolides together with beta-sitosterol, stigmasterol, taraxol, and liguhodgsonal whose structure was further confirmed by the (13)C-NMR techniques. The structures of the new constituents were elucidated by spectroscopic methods and shown to be 1beta, 10beta-epoxy-6beta(2'-hydroxymethylacryloyloxy)-8beta-hydroxy-eremophila-7(11)-en-12,8alpha-olide ( 1) and 1beta, 10beta-epoxy-6beta-(2'-hydroxymethylacryloyloxy)-8beta-ethoxy-eremophila-7(11)-en-12,8alpha-olide ( 2).

Assignment of a human DNA double-strand break repair gene (XRCC5) to chromosome 2

The Chinese hamster ovary (CHO-K1) cell mutant XRS-6 is defective in rejoining of DNA double-strand breaks and is hypersensitive to X-rays, gamma-rays, and bleomycin. Radiation resistance or sensitivity of somatic cell hybrids constructed from the fusion of XRS-6 cells with primary human fibroblasts strongly correlated with the retention of human chromosome 2 isozyme and molecular markers. Discordancies between some chromosome 2 markers and the radiation resistance phenotype in some of the hybrid cells suggested the location of the X-ray repair cross complementing 5 (XRCC5) gene on the p arm of chromosome 2. Introduction of human chromosome 2 by microcell-mediated chromosome transfer into the radiation-sensitive XRS-6 cells resulted in hybrid cells in which the radiation sensitivity was complemented. The chromosome 2p origin of the complementing human DNA in the microcell hybrids was supported by fluorescent in situ hybridization analysis of human metaphases using human DNA amplified from the hybrids by inter-Alu-PCR as chromosome-painting probes. XRCC5 is therefore provisionally assigned to human chromosome 2p.

Predatorial Borings in Late Precambrian Mineralized Exoskeletons

The late Precambrian tube-forming Cloudina, the earliest known animal to produce a mineralized exoskeleton, shows evidence of having been attacked by shell-boring organisms. Of more than 500 tubes from Shaanxi Province, China, 2.7% have rounded holes 40 to 400 micrometers in diameter. The relation between the size of the holes and the width of the bored tubes suggests that the attacking organism was a predator, selecting its prey for size. If true, this would be the oldest case of predation in the fossil record and would support the hypothesis that selection pressures from predation was a significant factor in the evolution of animal skeletons around the Precambrian-Cambrian boundary.

Branched-chain alpha-ketoacid dehydrogenase kinase. Molecular cloning, expression, and sequence similarity with histidine protein kinases

A cDNA for branched-chain alpha-ketoacid dehydrogenase kinase was cloned from a rat heart cDNA library. The cDNA had an open reading frame encoding a protein of 382 amino acid residues with a calculated molecular weight of 43,280. The clone codes for the branched-chain alpha-ketoacid dehydrogenase kinase based on the following: 1) the deduced amino acid sequence contained the partial sequence of the kinase determined by direct sequencing; 2) expression of the cDNA in Escherichia coli resulted in synthesis of a 43,000-Da protein that was recognized specifically by kinase antibodies; and 3) enzyme activity that phosphorylated and inactivated the branched-chain alpha-ketoacid dehydrogenase complex was found in extracts of E. coli expressing the protein. Northern blot analysis indicated the mRNA for the branched-chain alpha-ketoacid dehydrogenase kinase was more abundant in rat heart than in rat liver, as expected from the relative amounts of kinase activity expressed in these tissues. The deduced sequence of the kinase aligned with a high degree of similarity within subdomains characteristic of procaryotic histidine protein kinases. This first mitochondrial protein kinase to be cloned appears more closely related in sequence to procaryotic histidine protein kinases than to eucaryotic serine/threonine protein kinases.

Effects of clofibric acid on the activity and activity state of the hepatic branched-chain 2-oxo acid dehydrogenase complex

Feeding clofibric acid to rats caused little or no change in total activity of the liver branched-chain 2-oxo acid dehydrogenase complex (BCODC). No change in mass of liver BCODC was detected by immunoblot analysis in response to dietary clofibric acid. No changes in abundance of mRNAs for the BCODC E1 alpha, E1 beta and E2 subunits were detected by Northern-blot analysis. Likewise, dietary clofibric acid had no effect on the activity state of liver BCODC (percentage of enzyme in the dephosphorylated, active, form) of rats fed on a chow diet. However, dietary clofibric acid greatly increased the activity state of liver BCODC of rats fed on a diet deficient in protein. No stable change in liver BCODC kinase activity was found in response to clofibric acid in either chow-fed or low-protein-fed rats. Clofibric acid had a biphasic effect on flux through BCODC in hepatocytes prepared from low-protein-fed rats. Stimulation of BCODC flux at low concentrations was due to clofibric acid inhibition of BCODC kinase, which in turn allowed activation of BCODC by BCODC phosphatase. Inhibition of BCODC flux at high concentrations was due to direct inhibition of BCODC by clofibric acid. The results suggest that the effects of clofibric acid in vivo on branched-chain amino acid metabolism can be explained by the inhibitory effects of this drug on BCODC kinase.

Molecular cloning, stage-specific expression and cellular distribution of a putative protein kinase from Plasmodium falciparum

A putative protein kinase gene (PfPK2) has been isolated from the human parasite Plasmodium falciparum by using a mixed oligonucleotide pool which corresponds to a highly conserved region of serine/threonine protein kinases. The complete nucleotide sequence of 5 kb suggests the existence of a second transcriptional unit besides that of the PfPK2 gene, separated by a highly (A+T)-rich region and transcribed in a different orientation. No intron sequence exists in PfPK2. The predicted amino acid sequence of PfPK2 contains features characteristic of eukaryotic serine/threonine protein kinases. Within its putative catalytic domain it shares 33%, 30%, and 28% amino acid identities with rat calcium-calmodulin-dependent protein kinase, human protein kinase C, and bovine cAMP-dependent protein kinase, respectively. Outside the catalytic domain, however, PfPK2 has no homology with regulatory domains of other protein kinases, indicating PfPK2 might be modulated by signals different from those of higher eukaryotes or might be associated with other regulatory subunits. Using a specific antiserum raised in rabbits against a recombinant fragment of the protein expressed in Escherichia coli, PfPK2 was found to be expressed in a stage-specific fashion and mainly localized in the parasitic membrane.

[Effects of nitrogen, phosphorus and potassium on dry matter accumulation and nutrient contents of jobi]

The symptoms and influence of N, P and K deficiency on the dry matter accumulation and nutrient contents of Jobi were studied with sandy culture. The results have provided scientific basis for rational application of fertilizer.

[Pulmonary impedance plethysmographic features of obliterative pulmonary hypertension]

Pulmonary impedance plethysmography (PIP) has been used for the diagnosis of cor pulmonale secondary to COPD for about ten years. But the PIP features of obliterative pulmonary hypertension (OPH) have not yet been reported. We carried out a comparative study between PIP and hemodynamics determined by catheterization, in which 32 cases of OPH were studied. The results showed that the PIP features of OPH included a delayed delta Zmax peak, and the QZM interval had a positive linear correlation with pulmonary arterial pressure (r = 0.67, P less than 0.0001). According to electric field theory, it was supposed that this phenomenon might be due to narrowed pulmonary arterioles which limit the blood flow.

Role of tissue renin in the pathophysiology of hypertension in TGR(mREN2)27 rats

A transgenic rat line, TGR(mREN2)27, was established by introducing the murine Ren-2 gene into the genome of rats by microinjection techniques. These rats exhibit severe hypertension, making them an interesting model in which to study the role of renin in the pathophysiology of hypertension. However, although the additional renin gene is the only genetic difference compared with control rats, the exact mechanism of hypertension in TGR(mREN2)27 rats is still unclear. It cannot be attributed to a stimulation of the endocrine renin-angiotensin system or to an overexpression of renin in the kidney, since plasma and kidney renin and renin gene expression in the kidney are low in these animals. Here we describe recent progress made toward elucidating mechanisms of hypertension in TGR(mREN2)27 rats. 1) TGR(mREN2)27 rats were bred to homozygosity. The development of high blood pressure in homozygous rats is accelerated compared with that of heterozygous rats. This is paralleled by a higher mortality rate in homozygous TGR(mREN2)27 rats. Blood pressure and mortality rate of homozygous transgenic rats were effectively reduced by 10 mg captopril per kilogram body weight. 2) Treatment of 8-week-old heterozygous TGR(mREN2)27 rats with 10 mg/kg body wt per day of the angiotensin II receptor antagonist DuP 753 for 4.5 weeks normalized blood pressure. After withdrawal of the drug, blood pressure increased rapidly, reaching control levels after 3 weeks. In another group of TGR(mREN2)27 rats treated with 0.5 mg/kg per day, there was no change in blood pressure. Plasma renin and plasma angiotensin II were significantly higher in the high-dose group compared with the low-dose group.(ABSTRACT TRUNCATED AT 250 WORDS)

[Detection of cancer cells in peritoneal fluid or washing by immunocytochemical staining with monoclonal antibodies]

Three Monoclonal Antibodies (McAbs) against ovarian carcinoma and anti-CEA McAb were used for peroxidase-antiperoxidase (PAP) staining to detect cancer cells from 42 cases of either pleural fluid or ascites and peritoneal washings of cancer patients with ovarian cancer and endometrial carcinoma. The results showed that the positive rates by PAP staining of every group were higher than that by ordinary papanicolaou staining, especially in the group of epithelial ovarian carcinoma with primary surgery. There were significant differences by these two methods (P less than 0.05). It is concluded that a suitably chosen a panel of McAbs can be used in identifying differential diagnosis in ovarian cancer and the combined use of two methods will give more help to clinics.

A conditional yeast mutant deficient in mRNA transport from nucleus to cytoplasm

Transport of mRNA from nucleus to cytoplasm is critical for eukaryotic gene expression; however, the mechanism of export is unknown. Selection and screening procedures have therefore been used to obtain a family of temperature-sensitive conditional mutants of Saccharomyces cerevisiae that accumulate poly(A)+ RNA in the nucleus when incubated at 37 degrees C, as judged by in situ hybridization. In one such mRNA transport mutant, mtr1-1, RNA synthesis continues, the export of poly(A)+ RNA is inhibited, intranuclear poly(A)+ is remarkably stable, and protein synthesis gradually stops. Thus, there is no tight coupling between RNA synthesis and export. The export lesion is reversible. Although mRNA export is clearly not a default option, neither inhibition of protein synthesis, inhibition of mRNA splicing, nor inhibition of poly(A)-binding protein function blocks export of the average poly(A)+, as judged by in situ hybridization. Further analysis of the family of mtr mutants should help map the path of RNA transport.

[Mechanisms of protective action of radix Salviae miltiorrhizae (RSM) against experimental hepatic injury in rats]

The results indicated that RSM could significantly inhibit the lipid peroxidation of normal livers and cultured hepatocytes of rats, induce liver microsomal cytochrome P450 in normal rats, increase nucleic acids, proteins, urea and cerolloplasmin of damaged cultured hepatocytes of rats, relieve ultrastructural damage of cultured hepatocytes induced by CCl4. The pharmacological actions mentioned above should be considered as important mechanisms of RSM against liver injury.

Effect of Pinacidil on Spontaneous and Evoked Contractile Activity

Uninhibited bladder contractions have been associated with a variety of bladder dysfunctions including outlet obstruction, neurogenic bladder, incontinence, and other neurologic and nonneurogenic bladder disorders. One class of compounds that is gaining popularity and support for the treatment of hyperreflexia is potassium channel openers, such as pinacidil and cromakalim. In general, these agents act by hyperpolarizing the smooth muscle membrane, resulting in an increase in membrane stability which in turn would be expected to inhibit spontaneous and evoked contraction. It is the purpose of this study to compare the potency and selectivity of pinacidil at inhibiting both hyperreflexia in vivo, and several forms of in vitro contractile stimulation in the rabbit. The following is a summary of the results. (1) Pinacidil is an effective inhibitor of hyperreflexia in the in vivo rabbit model. (2) Pinacidil is a substantially more potent inhibitor of the amplitude of the hyperreflexia than the frequency. (3) Pinacidil was substantially more potent at inhibiting the contractile response to 2-Hz stimulation than to 32-Hz stimulation, but was equally effective at inhibiting field stimulation of the bladder base and body. (4) Pinacidil was significantly more potent at inhibiting the peak response to field stimulation than the rate of tension generation. (5) Pinacidil was equally potent and effective at inhibiting the phasic and tonic components of the response to field stimulation. (6) Pinacidil was a more potent inhibitor of methoxamine stimulation of the bladder base than bethanechol stimulation of the bladder body. (7) Pinacidil was a noncompetitive or mixed inhibitor of both methoxamine and bethanechol stimulation, whereas it was a competitive inhibitor of KCl stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Purification, characterization, regulation and molecular cloning of mitochondrial protein kinases

The mitochondrial kinases responsible for the phosphorylation and inactivation of rat heart pyruvate dehydrogenase complex and the rat liver and heart branched-chain alpha-ketoacid dehydrogenase complexes have been purified to homogeneity. The branched-chain alpha-ketoacid dehydrogenase kinase is composed of one subunit with a molecular weight of 44 kDa; pyruvate dehydrogenase kinase has two subunits with molecular weights of 48 (alpha) and 45 kDa (beta). Proteolysis maps of branched-chain alpha-ketoacid dehydrogenase kinase and the two subunits of pyruvate dehydrogenase kinase are different, suggesting that all subunits are different entities. The alpha subunit of the rat heart pyruvate dehydrogenase kinase was selectively cleaved by chymotrypsin with concomitant loss of kinase activity, as previously shown for the bovine kidney enzyme, suggesting that the catalytic activity of pyruvate dehydrogenase kinase resides in this subunit. Polyclonal antibodies against branched-chain alpha-ketoacid dehydrogenase kinase, purified by an epitope selection method, bound only to the 44 kDa polypeptide of the branched-chain alpha-ketoacid dehydrogenase complex, substantiating that the 44 kDa protein corresponds to the kinase for this complex. Both kinases exhibited strong substrate specificity toward their respective complexes and would not inactivate heterologous complexes. The kinases possessed slightly different substrate specificities toward histones. Phosphorylation and inactivation of the branched-chain alpha-ketoacid dehydrogenase complex by its purified kinase was inhibited by alpha-chloroisocaproate and dichloroacetate, established inhibitors of the phosphorylation of the complex. cDNAs encoding the branched-chain alpha-ketoacid dehydrogenase kinase have been isolated from rat heart and rat liver lambda gt11 libraries. This represents the first successful cloning of a mitochondrial protein kinase. Preliminary data suggest that two different isoforms of the kinase may exist in different ratios in various tissues. No evidence was found for induction of the branched-chain alpha-ketoacid dehydrogenase complex nor its kinase by clofibric acid. Rather, clofibric acid is a potent inhibitor of the activity of the branched-chain alpha-ketoacid dehydrogenase kinase and this may be the molecular mechanism responsible for the myotonic effects of clofibric acid in man.

Effects of Anoxia on the Biphasic Response of Isolated Strips of Rabbit Bladder to Field Stimulation, Bethanechol, Methoxamine and KCI

The contractile response of the bladder can be divided into two phases: an initial rapid increase in tension and a prolonged period of sustained tension (plateau phase). The bladder empties primarily during the plateau phase of the contractile response. These two phases can be differentiated using both pharmacologic and metabolic agents, indicating that the two phases have independent energy requirements. The present study compares the phasic (peak) and tonic (plateau) components of the responses of isolated strips of bladder body and base to field stimulation, bethanechol, methoxamine and KCl administration. New Zealand White rabbits were anesthetized with pentobarbital, and the bladder was removed. The bladder was divided between body and base at the level of the ureteral orifices. Three strips of bladder body and three strips of bladder base were mounted in separate baths containing Tyrode's solution at 37 degrees C and equilibrated with 95% O2, 5% CO2. Anoxia was produced by changing the gas mixture to 95% nitrogen, 5% CO2. The effects of anoxia on the responses to field stimulation, bethanechol, methoxamine and KCl were determined at different times after the initiation of anoxia. The results of these studies can be summarized as follows: (1) Anoxia induced time-dependent plateau phases of the response to field stimulation (2 and 32 Hz). (2) The rate of inhibition of the plateau phase was significantly and substantially greater than that of the peak phase in both the bladder body and base. (3) Similarly, anoxia inhibited the plateau phase of the bladder body's response to bethanechol to a significantly and substantially greater degree than anoxia inhibited the peak contraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Application of ray tracing to the design of a monolithic nonplanar ring laser

This paper presents some simple and useful-ray tracing techniques for the design of a monolithic nonplanar solid-state ring laser. With appropriate constraints the approach gives a complete cavity stability map and the angular and dimensional tolerances required for fabrication.

[Inhibitory effects of alcoholic extract of Cordyceps sinensis on abdominal aortic thrombus formation in rabbits]

Aortic thrombosis in de-endotheliazed rabbit and 51Cr labeled autologous platelets were used for the evaluation of in vivo effects of CsB-851 on platelet-vessel wall interaction. The result showed that when CsB-851, an active part of alcoholic extract of mycelium from Cordyceps sinensis (Berk.) Sacc., was infused intravenously, the 51Cr labeled platelet number per gram dry weight of injured abdominal aorta (98.14 +/- 9.41 x 10(6)) was much lower than that in the control group (201.25 +/- 27.21 x 10(6)) in a concentration dependent manner. This indicated that CsB-851 could inhibit thrombus formation at the de-endotheliazed surface of the aorta. Since it could inhibit platelet aggregation in vitro had no effect on coagulation function in vivo, it seemed that the inhibitory effect of CsB-851 on arterial thrombus formation was mainly related to the inhibition of platelet functions.

Endothelin-1 in human skin: immunolocalization, receptor binding, mRNA expression, and effects on cutaneous microvascular endothelial cells

Endothelin-1 (ET-1), a potent vasoconstrictor peptide, has been implicated in the maintenance of systemic and peripheral vascular tone. We have therefore sought direct evidence of a role for ET-1 in the regulation of blood flow and vascular tone in the human cutaneous microvasculature. Immunostaining for ET-1 was observed in all cutaneous blood vessels of normal human skin including the capillaries of the dermal papillae. Autoradiography showed specific binding of 125I-ET-1 over capillaries and larger blood vessels as well as hair follicles and sweat glands. In situ hybridization with a 32P-labeled RNA probe for ET-1 demonstrated mRNA for ET-1 in cultured human dermal microvascular endothelial cells (HDMEC). In HDMEC, basal release of PGE2 was significantly attenuated by ET-1 (100 pM-100 nM) (p less than 0.05, n = 7) with maximum inhibition in cells incubated with 10 nM ET-1. ET-1 also increased intracellular cAMP in a dose-dependent manner with a significant increase in HDMEC incubated with 100 nM ET-1 (p less than 0.05, n = 4). In HDMEC incubated with 100 nM ET-1, inhibition of PGE2 release was unaffected by the dihydropyridine Ca++ channel antagonist nifedipine or the extracellular Ca++ chelator EGTA, whereas the intracellular Ca++ chelator TMB-8 partially blocked the action of ET-1. In contrast, cAMP accumulation was significantly attenuated by EGTA (p less than 0.05, n = 4), nifedipine (p less than 0.05, n = 4), and TMB-8 (p less than 0.05, n = 4), indicating that the endothelial cell responses to ET-1 are complex and appear to involve both Ca(++)-sensitive and -insensitive pathways. These results provide evidence of an autocrine/paracrine role for ET-1 in the human cutaneous microvasculature.

[Effects of processing on toxicity and pharmacological action of Phytolacca americana L]

The experimental results have shown that the toxicity of variously processed Phytolacca americana is lower than that of the original rude drug, i.e. the local irritability tends to decrease by 16.7-83.3%; LD50 to elevate by 1.66-10.47 times; expectoration to increase by 1.10-1.57 times; but diuresis mostly to decrease by 16.0-45.0%. This reveals that the main object of processing Phytolacca americana is to lower toxicity, increase expectoration and relieve diuresis to reduce fluid retention.

Suppressive effect of high energy shock waves on tumor cells

Suppressive effect on tumor cells of high energy shock waves (HESW) has aroused the interest of physicians in recent years. We assessed experimentally the cytotoxic effects of HESW on tumor cells both in vitro and in vivo and determined whether a Chinese domestic lithotriptor is capable of generating effective HESW, which has the potential to break tumor cells, reduce cell viability, retard cell growth, delay doubling time, impair cell attachment and cell clonogenicity. In nude rats, HESW was able to delay tumor growth and reduce tumor size without evidence of metastasis. The nature of HESW in the induction of cell damage and its clinical application need to be further investigated.

[Study on the bias axis stress-strain relationship of the human mandible]

This paper presents our study on the bias axis elastic properties of the human mandible. The elastic coefficients were determined by the composite materials mechanical testing methods. From these values the "technical constants" were calculated to be: EL = 18.823GPa, ET = 12.777GPa, GLT = 5.564GPa, vLT = 0.302, vTL = 0.205. Variation of elastic constants of the human mandible with the orientation to its long axis was investigated. A brief description of the variation law is given. The bias axis stress-strain relationship of the human mandible is established. The data indicate that the human mandible is a living, anisotropic and nonhomogeneous composite biomaterial. Its mechanical properties have a close relation to its location, orientation and structure.

Porcine submaxillary mucin contains a cystine-rich, carboxyl-terminal domain in addition to a highly repetitive, glycosylated domain

The sequence of a 3.65-kilobase cDNA encoding a large portion of the polypeptide chain of porcine submaxillary mucin (apomucin) has been completed. The encoded polypeptide contains 1150 residues with the carboxyl-terminal 240 residues forming a globular domain that is rich in half-cystine, but deficient in sites for oligosaccharide attachment. The remaining 910 residues preceding the half-cystine-rich domain appear devoid of secondary structures, but they are rich in serine and threonine to which the O-linked oligosaccharides are bound. The first 391 residues of apomucin contain several tandemly repeated, identical sequences of 81 residues. Blots of genomic DNA partially digested with restriction nucleases show that at least 25 of these identical repeats are present in apomucin. The amino acid composition of apomucin isolated in the absence of protease inhibitors was shown earlier (Eckhardt, A. E., Timpte, C. S., Abernethy, J. L., Toumadje, A., Johnson, W. C., Jr., and Hill, R. L. (1987) J. Biol. Chem. 282, 11339-11344) to be devoid of half-cystine. In contrast, the amino acid composition of mucin purified in the presence of protease inhibitors contains half-cystine in amounts predicted by the cDNA sequence and also suggests that this mucin has about 25 tandem repeats. Thus, apomucin contains at least 2800 amino acid residues. Moreover, immunoblots of apomucin prepared in the presence or the absence of protease inhibitors, with antibodies specific for the half-cystine-rich domains or the tandem repeat sequences, show that the half-cystine-rich domain is absent in apomucin unless protease inhibitors are present throughout. Both types of mucin, however, contain the highly repetitive sequences. The molecular weight of undegraded apomucin has not been established exactly, but gel filtration in 6 M guanidine hydrochloride suggests that it is considerably higher than 250,000. RNA blot analysis shows that apomucin mRNA is large and polydisperse in accord with the message size necessary to synthesize the large apomucin polypeptide. These structural features of apomucin suggest a model for the structure of the mucin molecule that correlates well with its reported properties.

Expression of OKM5 antigen on keratinocytes in some dermatoses

Employing an avidin-biotin complex immunoperoxidase technique, it was found that there was OKM5 but no OKM1 antigen expression on the keratinocytes of the upper epidermis from all the studied specimens of seborrheic keratosis, verrucous nevus, Bowen's disease, BCC, SCC, MM, lichen planus, psoriasis vulgaris, condyloma acuminatum, and sporotrichosis as well as in two of eight cases of nevus pigmentosus. Our findings indicate that OKM5 antigen expression on epidermal keratinocytes is usually associated with dermal infiltration. It is assumed that human keratinocytes in cutaneous lesions, like the OKM1- OKM5+ monocyte/macrophage lineages, might play certain roles in immune responses and possibly function as antigen-presenting cells.

Comparison of crossbridge dynamics between intact and skinned myocardium from ferret right ventricles

This study compares the crossbridge kinetics of intact and skinned preparations from ferret cardiac muscles at 20 degrees C to determine whether skinning causes any alteration in the crossbridge response to an imposed length change. A papillary or trabecular muscle was isolated from the right ventricle, the muscle length adjusted to give the maximum twitch tension (Lmax), and the preparation was subjected to Ba2+ contracture. When steady tension developed, the length of the preparation was perturbed sinusoidally in 19 discrete frequencies, ranging from 0.13 to 135 Hz, and at a small peak-to-peak amplitude (0.25% Lmax). We identified three exponential processes in the sinusodial force-response to the imposed length oscillation, and these were labeled processes B, C, and D in order of increasing speed. A slow process, A, normally present in fast-twitch skeletal muscles, is very small or absent in cardiac muscles. Process B is an exponential delay, and the muscle produces oscillatory work on the forcing apparatus; processes C and D are exponential advances in which the muscle absorbs work. The preparation was chemically skinned and activated in the presence of (mM) CaEGTA 6 (pCa 4.55), MgATP 5, magnesium propionate 1, and phosphate 1, pH 7.0, with ionic strength adjusted to 200 mM with potassium propionate. We found that the crossbridge kinetics were not altered by the skinning procedure. The apparent rate constants extracted from the sinusoidal analysis were nearly identical in Ba2+ contracture (intact preparation) and in Ca2+ activation (skinned preparation), and the Nyquist plots were similar. Because the rate constants changed sensitively with the substrate (MgATP) concentrations, we concluded that the substrate is adequately supplied during Ba2+ contracture in the intact preparation. Our study demonstrates the compatibility of results obtained from an intact and from a skinned preparation.

[Research on the processing of Angelica based on the analysis of water soluble constituents]

In this paper, a comparative study on the contents of water-soluble and alcohol-soluble tannin and ferulic acid in Angelica and its processed products is reported. The result shows that different processing methods have significant effects on the above constituents, thus administering to the interpretation of the theory of Angelica processing.

Molecular defects in the E1 alpha subunit of the branched-chain alpha-ketoacid dehydrogenase complex that cause maple syrup urine disease

Maple syrup urine disease (MSUD) results from an inborn metabolic error caused by a deficiency of the branched-chain alpha-ketoacid dehydrogenase complex (BCKDC). cDNA clones encoding the E1 alpha subunit of BCKDC from rat and human liver have been isolated and characterized. The chromosomal location of E1 alpha on chromosome 19q13.1-13.2 has been determined using complementary methods. The etiology of MSUD has been studied by determining the enzyme activity, protein mass and mRNA level of BCKDC in fibroblasts from a human family and Polled Hereford calves, both with classic MSUD. A TACTyr to AACAsn substitution at residue 394 of the E1 alpha subunit was identified in the human patient by using enzymatic amplification of mRNA followed by DNA sequencing. Amplification of both mRNA and genomic DNA, in combination with allele-specific oligonucleotide hybridization, demonstrated that the patient was a compound heterozygote, inheriting an allele with a structural mutation from the father, and an allele from the mother containing a presumably cis-acting defect in regulation that abolished the expression of one of the E1 alpha alleles. The results revealed for the first time that a case of MSUD was caused by structural and regulatory mutations involving the E1 alpha subunit. Recent studies by others have demonstrated that the same structural mutation as is found in this patient is responsible for the high incidence of MSUD in the Philadelphia Mennonite population.(ABSTRACT TRUNCATED AT 250 WORDS)

[The preservation capacity of water and fertility of soilless cultivation substrate for Panax quinquefolium L.)]

The preservation capacity of water and fertility of several soilless cultivation substrates for Panax quinquefolium was compared in a large area. The data indicate that vermiculite mixed with sand (volume 1:1) is the most suitable soilless substrate for P. quinquefolium, for it is loose and features good preservation of fertility, water retaining, drainage, and air permeability. Timely analysis of nutrient contents in the substrates during cultivating period may serve as a guideline for correct application of fertilizer.

Phase Transition and Thermal Expansion of MgSiO 3 Perovskite

Results from in situ x-ray diffraction experiments with a DIA-type cubic anvil apparatus (SAM 85) reveal that MgSiO(3) perovskite transforms from the orthorhombic Pbnm symmetry to another perovskite-type structure above 600 kelvin (K) at pressures of 7.3 gigapascals; the apparent volume increase across the transition is 0.7%. Unit-cell volume increased linearly with temperature, both below (1.44 x 10(-5) K(-1)) and above (1.55 x 10(-5) K(-1)) the transition. These results indicate that the physical properties measured on the Pbnm phase should be used with great caution because they may not be applicable to the earth's lower mantle. A density analysis based on the new data yields an iron content of 10.4 weight percent for a pyrolite composition under conditions corresponding to the lower mantle. All current equation-of-state data are compatible with constant chemical composition in the upper and lower mantle; thus, these data imply that a chemically layered mantle is unnecessary, and whole-mantle convection is possible.

Effect of anoxia on in vitro bladder function

Previous studies have demonstrated that the ability of the in vitro whole bladder to empty in response to bethanechol administration was inhibited by anoxia while its ability to generate pressure decreased only slightly. One question was not addressed by these early studies: Is the anoxic effect selective for receptor-mediated contractile stimulation (as opposed to non-receptor-mediated contractile stimulation)? The present study was designed to compare the effect of anoxia on the ability of the in vitro bladder to generate pressure, sustain pressure, and empty in response to field stimulation (FS), bethanechol and KC1 administration. Each New Zealand white rabbit was anesthetized with pentobarbital and the bladder removed. The bladder was mounted as a whole-bladder preparation in a 300-ml isolated bath containing Tyrode's solution at 37 degrees C and equilibrated with 95% O2, 5% CO2. Anoxia was produced by changing the gas mixture to 95% nitrogen, 5% CO2. The effect of anoxia on the response to FS, bethanechol, and KCl was determined at different times after the initiation of anoxia. The results of these studies can be summarized as follows. (1) Anoxia induced a time-dependent decrease in the rate of pressure generation, the magnitude of pressure generation, and the percent volume emptied in response to FS and bethanechol. (2) At all time periods of anoxia, the ability of the bladder to empty was inhibited to a significantly greater degree than either the rate of magnitude of pressure generation (for both FS and bethanechol administration).(ABSTRACT TRUNCATED AT 250 WORDS)