Infrared optics of structured metal-insulator particulates

We show that rodlike particulates structured from interleaving layers of metal and insulator (or semiconductor) can exhibit novel infrared and far infrared characteristics that are tunable through the control of their geometric parameters. Results of scattering and absorption calculations are presented which demonstrate the validity of approximating the dielectric constant of the layered material by its effective medium value, thereby simplifying the prediction of the infrared properties. By clarifying the origin of the infrared absorption peaks, it is shown that the positions of the peaks are dependent on the transverse dimension of the particles as well as on the insulator dielectric constant and its relative fraction. The infrared characteristics of the structured particulates are contrasted with those of the metal, the insulator, and the semiconductor.

A 25-kilodalton ubiquitin carrier protein (E2) catalyzes multi-ubiquitin chain synthesis via lysine 48 of ubiquitin

Target protein multi-ubiquitination involving lysine 48 of ubiquitin (Ub) is known to occur during protein degradation in the ATP- and Ub-dependent proteolytic pathway (Chau, V., Tobias, J. W., Bachmair, A., Marriott, D., Ecker, D. J., Gonda, D. K., and Varshavsky, A. (1989) Science 243, 1576-1583). However, little is known about the enzymatic mechanism of multi-ubiquitination. We show that a purified Ub carrier protein, E2(25)K, catalyzes multi-Ub chain synthesis from purified Ub. Incubation of E2(25)K with Ub activating enzyme (E1), MgATP, and radiolabeled Ub (Mr = 8500) resulted in time dependent appearance of a "ladder" of radiolabeled Ub conjugates with molecular masses of 8.5n kDa, where n = 1, 2, 3, 4... (up to at least n = 10). The kinetics of this conjugative process were consistent with Ub2 acting as a steady-state intermediate. The putative Ub2 product of E2(25)K catalysis was purified and cleaved with a partially purified isopeptidase preparation. The sole cleavage product (Mr = 8500) had a tryptic digest identical to that of authentic Ub, confirming that the original conjugate was Ub2. Tryptic digestion of intact Ub2 gave products consistent with the existence of an isopeptide linkage between the COOH terminus of one Ub and Lys-48 of the other; this structure was confirmed by sequence analysis of the unique Ub2 tryptic fragment. Tryptic digestion of higher order Ubn adducts (n greater than or equal to 4) yielded fragments identical to those of Ub2, indicating that E2(25)K ligates successive Ub molecules primarily or exclusively via Lys-48. Although several other E2s supported synthesis of an apparent Ub2 adduct of undetermined linkage, only E2(25)K was capable of synthesizing multi-Ub chains from isolated Ub. Quantitative analysis of single turnovers showed that transfer from E2(25)K-Ub to Ub and Ub2 occurred with kappa 2 = 488 and 1170 M-1 min-1, respectively, at pH 7.3 and 37 degrees C. These results show that increasing the number of Ub molecules in a chain increases susceptibility to further ubiquitination by E2(25)K. Ub2 was a good substrate for activation by E1 and was readily transferred to E2(25)K. The labile E2(25)K-Ub2 adduct was catalytically active, and exhibited preference for Ub2 (versus Ub) as acceptor. These results suggest that E2(25)K may function as a multi-ubiquitinating enzyme in the Ub-dependent proteolytic pathway.

The Kangmar Dome: A Metamorphic Core Complex in Southern Xizang (Tibet)

The Kangmar metamorphic-igneous complex is one of the most accessible examples of an enigmatic group of gneiss domes (the North Himalayan belt) that lies midway between the Greater Himalaya and the Indus-Tsangpo suture in southern Tibet. Structural analysis suggests that the domal structure formed as a consequence of extensional deformation, much like the Tertiary metamorphic core complexes in the North American Cordillera. Unlike its North American counterparts, the Kangmar dome developed in an entirely convergent tectonic setting. The documentation of metamorphic core complexes in the Himalayan orogen supports the emerging concept that extensional processes may play an important role in the evolution of compressional mountain belts.

Thrombolytic therapy and the nursing profession. Results of a statewide survey

A statewide survey of 624 nurses in 92 hospitals in Massachusetts indicates that recombinant tissue-type plasminogen activator and streptokinase are the most widely available thrombolytic agents. Nurses play an active role in drug reconstitution and administration, but only 20% of the total respondents participate consistently in screening procedures. The majority of patients were informed about the risks and benefits of treatment before initiation of therapy. Nurses reported their major management concern was internal bleeding, with cost of treatment being a minor concern.

Chloroplast DNA polymorphism in fertile and male-sterile cytoplasms of sorghum (Sorghum bicolor (L.) Moench)

Restriction endonuclease patterns of chloroplast DNA (cpDNA) were consistently distinguishable between fertile and male-sterile cytoplasms of sorghum [Sorghum bicolor (L.) Moench], whereas no differences in restriction patterns of cpDNA among male-sterile (A1) lines, including six isocytoplasmic strains, were revealed in this study. It is suggested that chloroplast DNA may contribute to the male sterility of A1 lines used currently in hybrid sorghum production.

Vagal-induced vomiting in decerebrate cat is not suppressed by specific 5-HT3 receptor antagonists

Cancer therapy with cytotoxic drugs such as cisplatin or cyclophosphamide is usually associated with violent crisis of vomiting. Recently, it was shown that 5-HT3 receptor antagonists block cisplatin-induced vomiting but the mechanisms and their sites of action remain unknown. We tested the hypothesis that these agents act on structures within the central nervous system by evaluating the effectiveness of vagal stimulation in eliciting fictive vomiting in decerebrate, paralyzed and ventilated cats before and after administration of such agents. Fictive vomiting was defined as a series of large bursts of synchronous activity in the phrenic and abdominal (expiratory) nerves (retching) followed by a burst in which the abdominal activity was prolonged (expulsion). The latency and number of these co-activations were measured before and after intravenous administration of three 5-HT3 receptor antagonists (GR 38032F (Ondansetron). Zacopride, and BRL 43694A (Granisetron]. All compounds, administered at doses of 1 and 2 mg/kg failed to block vomiting behaviour in 100% and 68% of trials, respectively. Nor did their administration affect the latency and number of co-activations. We conclude that intravenous administration of 5-HT3 receptor antagonists do not act centrally on either the brainstem neuronal network known as the "vomiting center" or related neuronal structures. Our results suggest that the anti-emetic effect of 5-HT3 receptor antagonists in cisplatin-induced vomiting is mediated peripherally rather than centrally.

[A study on the dental adhesive containing phosphate diesters]

Although a lot of kinds of dental adhesives have been applied recently, all of them cannot meet clinical requirement completely. This paper reports a new dental adhesive containing partial phosphate diesters developed by us. We synthesized aryl phosphorodichloridates (APDC), nine kinds of phosphate diester (PDE) adhesive monomers, sodium p-toluenesulfinate (TSS) and p-toluenesulfinic acid (TSA) accelerators, polymethyl methacrylate (PMMA) powder and the other compounds. The chemical structures of PDE adhesive monomers were confirmed by IR, 1HNMR, 31PNMR, refractive index and elementary analysis etc. The results showed that the tensile bond strength (TBS) between PDE dental adhesive and human tooth was better than others reported in China and some others reported in literature.

Identification and characterization of transcriptional arrest sites in exon 1 of the human adenosine deaminase gene

Analysis of human adenosine deaminase (ADA) gene transcription in four different cell lines indicated that a high density of RNA polymerase II complexes is present at the 5' end of the gene and that the extent of transcription elongation beyond the promoter-proximal region governs gene expression. To determine the sequence requirements for a potential transcription arrest site in the promoter-proximal region, genomic clones containing the ADA promoter, exon 1, and various lengths of intron 1 were injected into Xenopus laevis oocyte germinal vesicles. Transcription analysis indicated that nascent ADA transcripts were highly represented at the promoter-proximal region of the injected templates, suggesting that transcription arrest occurred in the oocyte transcription system. Analysis of the transcription products indicated that ADA transcription initiated at the authentic start site and that the most prominent, short ADA transcripts were 105 nucleotides in length. The 3' end of these transcripts mapped within exon 1, 10 nucleotides downstream of the translation initiation codon. Deletion analysis demonstrated that sequences within exon 1 were sufficient to specify the synthesis of the 105-nucleotide transcripts. Taken together, these data suggest that a transcription arrest mechanism operates in the promoter-proximal region of the human ADA gene and that regulation of elongation beyond this point plays a major role in regulating ADA gene expression.

Sequence diversity in the 5' untranslated region of rabbit muscle phosphofructokinase mRNA

DNA sequences of two full-length rabbit muscle phosphofructokinase (RMPFK) cDNAs (A and B) show identical coding sequence but heterogeneous 5' untranslated regions. cDNA-A is formed by removal of a 1.7 kb upstream intron while cDNA-B retains the 3' region of this intron. A 2.8 kb upstream sequence of RMPFK gene contains several features characteristic of housekeeping genes: high GC content (67%) at its 5' end, with 50 CpG sites; five Sp1 sites; and no functional TATA box. Comparison of the 5' sequences of the two RMPFK cDNAs and three human muscle PFK cDNAs (Nakajima, H., et al., (1990) Biochem. Biophys. Res. Com. 166, 637) suggests that a single splicing event occurs involving different splicing donor sites but the same splicing acceptor site, resulting in diversity in the upstream sequence. These observations suggest that transcription of muscle PFK gene may start at multiple sites, another feature of housekeeping genes.

Transfer function analysis of the ventricular function: a new method for calculating right ventricular ejection fraction

The relationship between the ventricular transfer function and ejection fraction has been investigated by the routine procedure of first-pass radionuclide angiocardiography. Ejection fraction has been shown to equal 1-e(-b), where b is the ratio of the R-R interval over the mean transit time difference between ventricular and atrial time-activity curves. To evaluate the effect of region of interest (ROI) on the right ventricular ejection fraction (RVEF), the results of the transfer function analysis (TFA) technique using precise ROI, TFA using rectangular ROI, and the routine method were compared. Regression analyses among RVEFs obtained from the above ROI methods yielded good correlations. Reliable RVEFs have been obtained even in the case of an improper bolus injection. Thus, the TFA technique is a new, simple, and reliable method for calculating RVEF without needing to outline the right ventricle precisely.

Specific inhibition of interleukin 3 bioactivity by a monoclonal antibody reactive with hematopoietic progenitor cells

HIM1, originally designated HI98, a murine monoclonal IgM antibody raised against human mononuclear cells, has been reported at the Fourth International Leukocyte Typing Workshop (called antibody M0141) to be the only one of 157 antibodies tested that inhibited binding of interleukin 3 (IL-3) to KG-1 human acute myelogenous leukemia cells and normal human monocytes. We have carried out detailed studies of the selective effect of HIM1 on IL-3-mediated stimulation of hematopoietic progenitors. Preincubation of normal human bone marrow mononuclear cells, depleted of adherent cells and T cells, with HIM1 antibody resulted in a dose-dependent inhibition of IL-3-mediated stimulation of both erythroid burst-forming units (maximum inhibition 55%) and granulocyte/macrophage colony-forming units (maximum inhibition 49%). HIM1 antibody had no effect on growth of erythroid colony-forming units in culture. In addition, preincubation of the cells with HIM1 antibody had no deleterious effect on granulocyte/macrophage colony-stimulating factor-induced growth of either erythroid bursts or granulocyte/macrophage colonies. To be certain that the HIM1 antibody did not react directly with IL-3 itself, we attempted to use immunodepletion to remove IL-3 that had been added to our culture medium. Although we were able to remove IL-3 bioactivity by immunodepletion with anti-IL-3 antibody bound to Sepharose beads, beads with attached HIM1 did not remove IL-3 activity from the medium. Polymorphonuclear neutrophils bind high levels of HIM1, although they have very few or no detectable IL-3 receptors. Therefore, this antibody appears to recognize a cell surface antigen that is critical for optimal IL-3 binding and bioactivity but is not the actual IL-3 receptor.

Substance P in the ventrolateral medulla oblongata regulates ventilatory responses

Local injection of substance P (SP) into the ventral portion of the nucleus gigantocellularis, nucleus reticularis lateralis, and nucleus retrofacialis of the ventrolateral medulla oblongata (VLM) or direct application on the ventral surface of the medulla oblongata caused marked stimulation of tidal volume (VT) and/or minute ventilation (VE). The ventilatory response to hypoxia was significantly blunted after SP in the VLM but not in the dorsal medulla oblongata (DM) (nucleus tractus solitarius). The SP antagonist [D-Pro2,D-Trp7,9]SP almost completely inhibited this response when applied locally to a wide area of the superficial layer of the VLM but not of the DM. Unilateral or bilateral application of 0.3-1.5 nmol of the SP antagonist in the VLM (corpus trapezoideum and the caudal region extending from the rootlets of the nucleus hypoglossus to the first cervical segment) markedly attenuated the response to a 5% CO2 inhalation. The inhibition of the CO2 response was seen after [D-Pro2,D-Trp7,9]SP in the rostral areas of the medulla oblongata corresponding to the corpus trapezoideum and the caudal region extending from the rootlets of the nucleus hypoglossus to the first cervical segment of the cervical cord. Electric somatosensory-induced ventilatory stimulation could be depressed by approximately 70% by [D-Pro2,D-Trp7,9]SP locally applied on the surface of the VLM. We conclude that SP is involved in the hypoxic, hypercapnic, and somatosensory ventilatory responses in the rat. However, these respiratory reflexes are mediated via different neuronal pools in the medulla oblongata, mainly the VLM.

[Pathologic morphology of the indented tongue]

This paper use the methods of light microscope, electronmicroscope to observe the appearance of pathology and morphology of the convex and concave parts of the indented tongue edge, and examine the histology of normal tongue edge as a contrast. The authors consider that the main pathological changes of the indented tongue are: Thinning of the epithelial layer; change of rough endoplastic retica; reducing in tonofilaments; edema of cells and tissues, and decreasing in elastic fibers and collagenic fibers, etc.

Identification of a new type II restriction endonuclease, BsaAI

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A new Ph1+, bcr cell line derived from a patient with ALL-L1 gained autonomy in culture concomitant to CD23 expression

A permanent cell line, LEF1, has been established from the cells of an adult suffering from a Philadelphia positive acute lymphoblastic leukemia. The LEF1 cell line was obtained by maintaining peripheral blood cells from the patient in culture on a fibroblast feeder; subsequently, an autonomously growing cell population, independent of that feeder layer, developed. The karyotype of the cell line, 46, t(9;22)(q34;q11), was different from the karyotype at diagnosis which had 53 chromosomes and two Philadelphia chromosomes. Furthermore, compared with the initial leukemic blasts, the immortalized cell had three differences in surface phenotype (CD23+, CD11b-, CD10-). However, molecular studies indicated that the breakpoint in the 3' part of the first intron of the BCR gene was unchanged, confirming the leukemic origin of LEF1. The cell line was shown to be Epstein-Barr virus negative.