Aggregating human platelets in carotid sinus of rabbits decrease sensitivity of baroreceptors

Aggregating platelets release factors that act in a local paracrine manner to alter vascular tone. The purpose of the present study was to explore the possibility that factors released from aggregating platelets may alter the sensitivity of arterial baroreceptors. Baroreceptor activity was recorded from the vascularly isolated carotid sinus of rabbits anesthetized with sodium pentobarbital. The carotid sinus was filled with oxygenated Krebs-Henseleit buffer and distended with slow ramp increases in nonpulsatile pressure. Sensitivity of baroreceptors to increased pressure was determined before and during intraluminal exposure of the sinus to washed human platelets suspended in Krebs' buffer. Platelets activated with thrombin (0.4 units/ml) decreased baroreceptor activity and the slope of the pressure-activity curve significantly (n = 6). The platelet-induced decrease in baroreceptor sensitivity was related to the duration of exposure to platelets with no change in baroreceptor activity after 4 minutes and a progressive decrease in activity over the next 12 minutes. The slope of the pressure-nerve activity relation averaged 1.26 +/- 0.08 %/mm Hg during control and decreased to 0.97 +/- 0.22, 0.80 +/- 0.19, and 0.53 +/- 0.15 %/mm Hg after 12-16 minutes of exposure to 10(7), 10(8), and 3-6 x 10(8) activated platelets/ml, respectively (p less than 0.05). Baroreceptor sensitivity was restored after removal of platelets from the carotid sinus. Thrombin alone had no effect on baroreceptor sensitivity. Activated platelets did not alter the carotid pressure-diameter relation, suggesting a direct inhibitory effect on baroreceptors. The slope of the pressure-activity curve and maximum baroreceptor activity were not decreased by the stable thromboxane analogue U46619, serotonin, or ADP.(ABSTRACT TRUNCATED AT 250 WORDS)

Transmembrane region of wild-type and mutant M13 coat proteins. Conformational role of beta-branched residues

Although transmembrane (TM) segments of integral membrane proteins are putatively alpha-helical in conformation, beta-sheet promoters (Val, Ile, Thr) often account for approximately 40% of TM residue composition. We are examining the conformational role(s) of these residues, using as a model system the major coat protein of the filamentous bacteriophage M13. This 50-residue protein, which is located at the Escherichia coli host membrane during phage reproduction, contains a prototypic 19-residue hydrophobic midregion (residues 21-39: YIGYAWAMVVVIVGATIGI). Using "Eckstein" site-directed mutagenesis, we have generated several viable M13 coat protein mutants with beta-branched amino acid substitutions within their TM region. Mutant coat proteins, including Ile32----Val (I32V) and Ala27----Thr (A27T), were obtained in milligram quantities by growing M13 mutant phages in liter preparations, confirming that these coat proteins are capable of assuming their normal biological function(s) in phage reproduction. Circular dichroism spectroscopy performed in the membrane-mimetic medium of deoxycholate micelles indicated comparable alpha-helical contents of mutants I32V and A27T to wild-type protein. 13C nuclear magnetic resonance experiments with mutant A27T demonstrated that the combination of additional beta-branched content and introduction of an -OH substituent induced chemical shift and temperature-dependent changes and influenced the local protein environment at sites up to 12 residues remote from the mutation site. In contrast, mutant I32V (of which a salient feature is a mid-TM pentavaline segment) behaved very similarly to wild-type coat. These findings are interpreted in terms of the range of TM secondary structure and stability which can be accommodated by viable M13 coat protein mutants.

[A mid-infrared spectra study of a series of benzocrown ether and macrocyclic polyether diester]

With a Nicolet 20 SX B Fourier Transform infrared spectrometer, the mid-infrared spectra in region of 4000-400 cm-1 were observed for a series of benzocrown ether and macrocyclic polyether diester. A difference in the wavelength of absorption of the ether bond was found between benzocrown ether and macrocyclic polyether diester. The wavelength of absorption of the ether bond of the compounds I-IV moved down about 25 cm-1, as compared with that of the compounds V-IX.

Plasminogen activator activity and thymidine incorporation in avian granulosa cells during follicular development and the periovulatory period

The hormonal and second messenger regulation of plasminogen activator (PA) activities in avian granulosa and theca cells has been documented. However, the physiological role(s) of PAs in the avian ovary remains poorly understood. The present studies were designed to evaluate PA activity in hen granulosa cells collected from the most mature (F1) preovulatory follicle at three discrete time points relative to a spontaneous ovulation and from follicles collected at various stages of follicular development. Levels of PA activity in the granulosa layer of the F1 follicle declined by greater than 90% as follicles were collected closer to their anticipated time of ovulation (e.g., from 17-16 h to 0.75-0.15 h; p less than 0.05). Timing of tissue collection was confirmed by evaluation of serum progesterone levels, which peaked as expected at the 6-5-h time point. During follicular development, PA activity was several times greater in rapidly growing follicles (6-12 mm, 1-3 wk prior to ovulation) than in slowly growing (1-5 mm) or preovulatory (F3 and F1) follicles (p less than 0.05). Granulosa cells of these rapidly growing follicles also incorporated significantly higher levels of 3H-thymidine than did granulosa cells of mature follicles (p less than 0.05), suggesting a higher level of DNA synthesis. Similarly, granulosa cells of the mitotically active germinal disc region of the F1 granulosa layer were found to possess at least 3-fold higher (p less than 0.05) levels of PA activity and a 2-fold greater level of 3H-thymidine incorporation than the more mature granulosa cells isolated from the remaining F1 granulosa layer.(ABSTRACT TRUNCATED AT 250 WORDS)

Proteus penneri isolated from the pus of a patient with epidural abscess

P. mirabilis and P. vulgaris are the two wellknown species in the genus Proteus. P. myxofaciens and P. penneri are recent additions to the genus. We isolated P. penneri from the pus of a patient with suppurative otitis media and an epidural abscess. The characteristics of the organism, including morphology, staining, physiology and biochemistry, were studied. Clinical microbiological laboratories should suspect P. penneri in the case of as Proteus strain that is negative for indole, salicin and esculin, but otherwise resembles P. vulgaris. Proteus penneri, formerly known as Proteus vulgaris indole-negative or as Proteus vulgaris biogroup 1, was named by Hickman et al in 1932. Little information about human infection by this organism is available. In 1982, Hickman and co-workers studied 20 strain of P. penneri which were isolated from clinical specimens (urine, stool, etc.) in the USA. However, its clinical significance, until recently, was unknown. We isolated a strain of P. penneri from the pus of a patient with suppurative otitis media and an epidural abscess on June 10 and 15, 1989. This paper concerns the problems encountered in identifying this organism and its clinical significance.

[Model of atrophic gastritis in rats by various method]

Model of atrophic gastritis was made in rats by synthetical method which comprised twice of active immunization and continual oral administration of bile and hot water for 70 days. There was a highly significant difference (P less than 0.01) between the normal group and testing group in the number of rats with changes in body-weight, PH value of gastric mucous membrane, gastric membrane blood flow (GMBF) and its potential difference (PD), and pathology (thinned mucous membrane, decreased gland, infiltration of inflammatory cells and intestinal metaplasia). By observations for additional 45 days, the above-mentioned values still showed significant or highly significant differences (P less than 0.05 or P less than 0.01) between the testing group and the normal group. The animal model of atrophic gastritis made by this method can be used for the valuation of drug efficacy.

[Detection of hepatitis B virus DNA in leucocytes of primary hepatocarcinoma using polymerase chain reaction]

The detection of HBV DNA in sera and leucocytes of 30 primary hepatocarcinoma patients whom were negative for HBsAg by reverse passive hemagglutination using polymerase chain reaction (PCR) were reported. The detectable rates of HBV DNA in leucocytes and sera were 86.7% and 70% respectively and the serological indexes, 43.4%. These indicated that HBV DNA may existent in blood of the patients with negative serological indexes. It was common that HBV DNA presented in peripheral leucocytes of primary hepatocarcinoma, indicated that extrahepatic sites of the HBV genome, and perhaps replication of HBV virus, existed. It was of great importance for the role of HBV DNA in lemology and epidemiology, etiology of hepatocarcinoma, diagnosis and treatment of infection as well as standard of cure.

Interleukin-1 beta directly excites hypothalamic supraoptic neurons in rats in vitro

Responses of 42 neurosecretory neurons in the supraoptic nucleus (SON) to human recombinant interleukin-1 beta (IL-1 beta) were examined during intracellular recordings in rat brain slices. IL-1 beta (10(-9)-10(-8) M) depolarized the membrane and caused increased firing in 25 neurons (59.5%). In 11 other neurons (26.6%), depolarization was also seen, followed by membrane hyperpolarization. The IL-induced depolarizing effect remained in the presence of tetrodotoxin (TTX) but was abolished by sodium salicylate. The results suggest that IL-1 beta mainly exerts a direct excitatory effect on SON neurons and further, that prostaglandins may be involved in such an effect.

[An experimental study of shedan chuangbei oral liquid with low sucrose content]

The shedan chuangbei oral liquid in low sucrose content by adding stevioside not only reduces the cost of preparation but has better stability in quality and clarity. Qualitative analysis, TLC and determination of alkaloids all show correspondence in composition between the original drug and the new preparation.

Chemical climatology of high elevation spruce-fir forests in the southern Appalachian mountains

The physical and chemical climatology of high elevation (> 1500 m) spruce-fir forests in the southern Appalachian mountains was studied by establishing a weather and atmospheric chemical observatory at Mt Mitchell State Park in North Carolina (35 degrees 44' 05" N, 82 degrees 17' 15"W). Data collected during the summer and autumn (May-October) of 1986, 1987, and 1988 are reported. All measurements were made on or near a 16.5 m walk-up tower extending 10 m above the forest canopy on Mt Gibbes (2006 m msl), which is located approximately 2 km SW of Mt Mitchell. The tower was equipped with standard meteorological instrumentation, a passive cloud water collector, and gas pollutant sensors for O3, SO2, NOx. The tower and nearby forest canopy were immersed in clouds 25 to 40% of the time. Non-precipitating clouds were very acidic (pH 2.5-4.5). Precipitating clouds were less acidic (pH 3.5-5.5). The dominant wind directions were WNW and ESE. Clouds from the most common wind direction (WNW) were more acidic (mean pH 3.5) than those from the next most common wind direction (ESE, mean pH 5.5). Cloud water acidity was related to the concentration of SO4(2-), and NO3- ions. Mean concentration of H+, NH4+, SO4(2-), and NO3- ions in the cloud water varied from 330-340, 150-200, 190-200 and 120-140 micromol litre(-1) respectively. The average and range of O3 were 50 (25-100) ppbv (109) in 1986, 51 (26-102) ppbv in 1987, and 66 (30-140) during the 1988 field seasons, respectively. The daily maximum, 1-h average, and 24-h average concentrations were all greatest during June through mid-August, suggesting a correlation with the seasonal temperature and solar intensity. Throughfall collectors near the tower were used to obtain a useful estimate of deposition to the forest canopy. Between 50-60% of the total deposition of SO4(2-) was due to cloud impact.

Desmosome assembly in MDCK epithelial cells does not require the presence of functional microtubules

Desmosomes, complex multisubunit structures that assemble at sites of cell-cell contact, are important components of the epithelial junctional complex. Desmosome assembly requires the coordinated interaction at the plasma membrane of at least 8 cytoplasmic and integral membrane proteins organized into two structurally and functionally distinct domains, the cytoplasmic plaque and membrane core. Previous studies (Pasdar et al., J. Cell Biol., 113:645-655) provided evidence that cytokeratin filaments and microtubules may regulate transfer and assembly of cytoplasmic plaque and membrane core proteins, respectively. To determine directly the role of microtubules in these processes, Madin-Darby canine kidney (MDCK) cells were treated with nocodazole or colchicine to disrupt the microtubular network. Biochemical analysis of the different components of the cytoplasmic plaque and membrane core domains revealed little or no effect of nocodazole or colchicine on the kinetics of synthesis, post-translational modifications, transfer of proteins to the plasma membrane or their metabolic stability in the presence or absence of cell-cell contact. Likewise, immunofluorescence analysis of desmosome formation demonstrated an apparently normal desmosome assembly in the presence of nocodazole or colchicine upon induction of cell-cell contact. These results indicate that an intact microtubular network is not necessary for the processing or transport of the desmosomal membrane core glycoproteins to the plasma membrane in the absence or presence of cell-cell contact. Furthermore, the integration of the cytoplasmic plaque and membrane core domains induced by cell-cell contact at the plasma membranes of adjacent cells does not require the presence of functional microtubules.

The selection of portal aperture using interactively displayed Beam's Eye Sections

Portal apertures are often defined by wax-pencil lines drawn on simulator films. The simulator-film images suffer degradation due to X ray absorption and scatter in tissues proximal to and distal to the intended target volume. We describe a method for avoiding the degradation by using a 3-D dataset to produce high-contrast section images with a user-defined orientation. The calculation of these Beam's Eye Section (BES) images requires a set of medium-to high-resolution transverse section data (the 3-D dataset), as well as a medium- to high-performance computer workstation. These CT-like section images, providing more contrast and detail than a projection (that is, a simulator or Digitally Reconstructed Radiograph [DRR]) image, should allow for more accurate selection of portal apertures. The BES image plane is oriented perpendicular to the central axis of a user-selected beam. Once the user has created a beam, the system allows the user to step along that beam with a new BES image produced at each step. Contours manually drawn on these BES images are ultimately projected onto a DRR image. The outermost segments of these sometimes crisscrossing contours (the union of all projected areas) accurately defines the portal aperture needed to encompass the target at all levels.

Esophageal diverticulum associated with carcinoma of the esophagus--a report of four cases

During a 25-year period, four patients with esophageal diverticulum associated with carcinoma of the esophagus underwent surgery. The results were satisfactory. The clinical features included a long history of diverticulum and the presence of a carcinoma of the esophagus in close proximity to the former. Inflammation within the diverticulum and in the mucosa around the diverticulum was noted. The closer the diverticulum to the carcinoma, the more severe the inflammation. Therefore, diverticulitis and esophagitis may be important factors leading to the development of carcinoma of the esophagus, and patients with esophageal diverticulum should be followed up regularly and the diverticulum resected as early as possible if inflammation within the diverticulum or peri-diverticular esophagitis is found.

[Clinical early diagnosis of tuberculous meningitis]

We examined 37 tuberculous meningitis, 30 active pulmonary tuberculosis, and 31 nontuberculous disease patient's CSF and serum antitubercular antibody IgG with polymerized OT as an antigen by the method of ELISA, respectively. It is shown that there is of a specificity to the diagnosis of tuberculous meningitis. We also reexamined the serum antitubercular antibody daily, as well as CSF antitubercular antibody, and CSF routine and biochemical indexes weekly for 16 tuberculous meningitis inpatients ill no more than five days. It was found that CSF antitubercular antibody became positive five days earlier than self serum antitubercular antibody, seven days earlier than typical tuberculous meningitis CSF. It is shown that the positive of the CSF antitubercular antibody may be used as the basis of the early diagnosis of tuberculous meningitis. Through antitubercular therapy and monthly re-examinations of the above indexes, it was found that CSF and serum antitubercular antibody became negative earlier than the recovery of CSF routine and biochemical indexes, and so the examination of CSF and serum antitubercular antibody has some reference value to determine curative effects and prognosis.

Anatomical evidence for an intergeniculate leaflet in Rana pipiens

The projections of the nucleus of Bellonci and the anterior thalamic nucleus in Rana pipiens appear to be remarkably similar to those that have been described for the mammalian intergeniculate leaflet. The connections of these nuclei were examined using both the anterograde and retrograde transport of horseradish peroxidase. Afferents to the neuropil of Bellonci and its nucleus include bilateral projections from the retina, the contralateral nucleus of Bellonci, and anterior thalamic nucleus as well as bilateral projections from the pretectum and the ipsilateral suprachiasmatic nucleus. Efferent projections observed following HRP injections in the anterior thalamus consist of three components: (1) a ventral hypothalamic-suprachiasmatic and commissural projection, (2) a dorsal descending tract to the pretectum and tectum, and (3) a ventral descending tract to the somatomotor brainstem.

Biosynthesis in vitro of SA-Lex and SA-diLex by alpha 1-3 fucosyltransferases from colon carcinoma cells and embryonic brain tissues

The sialyl-fucosyl-lactosamine-epitope present in sialyl (SA)-Lex (NeuAc alpha 2-3Gal beta 1-4 [Fuc alpha 1-3]GlcNAc beta 1-3Gal beta 1-4Glc-Cer), a carcinoembryonic antigen, has been recognized recently as a ligand for the binding of leukocyte-endothelial cell adhesion molecule 1 (LECAM-1) to myeloid and tumour cell surfaces. We have recently detected the presence of an alpha 1-3 fucosyltransferase (FucT-3) activity in both embryonic chicken brain (ECB) and human colon carcinoma cells (Colo-205) which catalyses the biosynthesis in vitro of SA-Lex and SA-diLex. Fucosyltransferase activities from both sources are stimulated in the presence of divalent cations (Mn2+, Mg2+, Ca2+, Co2+ and Fe2+), although absolute metal requirement is not observed. Substrate specificity studies with this partially purified (ECB, 3000-fold; Colo-205, 100-fold) novel FucT-3 indicate the preference for terminally sialyl-substituted glycolipid acceptors, as observed by the lower Km values when sialyl-neolactotetraosyl ceramide, LM1, (Neu-Gc alpha 2-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4 Glc-Cer; Km = 0.048 mM) and sialyl-norhexaosylceramide, NeuGc-nLc6, (Neu-Gc alpha 2-3Gal beta 1-4 GlcNAc beta 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc-Cer; Km = 0.032 mM) were used as substrates. Fucosyltransferase from Colo-205 requires the presence of the acyl group of the ceramide moiety and an acetyl group on glucosamine in the acceptor glycolipid since lyso-LM1 was found to be completely inactive.(ABSTRACT TRUNCATED AT 250 WORDS)

Comprehensive assessment of long-term postoperative continence in pediatric imperforate anus. Clinical, manometric and contrast studies

109 patients with imperforate anus were followed up postoperatively for 5 to 28 years. Postoperative continence was evaluated by anorectal manometry, barium enema and clinical symptoms. A comprehensive assessment system, combining the clinical and objective systems was designed which can reflect postoperative anal continence function completely and objectively. It is useful for determining the causes of incontinence and its treatment.

Viable transmembrane region mutants of bacteriophage M13 coat protein prepared by site-directed mutagenesis

Bacteriophage M13 coat protein - a 50-residue protein located at the E. coli host membrane during phage reproduction - is subjected to cytoplasmic, membrane-bound, and DNA-interactive environments during the phage life cycle. In research to examine the specific features of primary/secondary structure in the effective transmembrane (TM) region of the protein (residues 21-39: YIGYAWAMVVVIVGATIGI) which modulate its capacity to respond conformationally to the progressive influences of these varying environments, we have prepared over two dozen viable mutant phages with alterations in their coat protein TM regions. Mutants were obtained through use of site-directed mutagenesis techniques in combination with three "randomized" oligonucleotides which spanned the TM region. No subcloning was required. Among mutations observed were those in which each of the four TM Val residues was changed to Ala, and several with increased Ser or Thr content, including one double Ser mutant (G23S-A25S). Polar substitutions arising at Gly23 and Tyr24-including G23D, Y24H, Y24D and Y24N-suggested that this local segment resides external to the host membrane. Milligram quantities of mutant coat proteins are obtained by growing M13 mutant phages in liter preparations, with isotopic (e.g., 13C) labelling at desired sites, for subsequent characterization and conformational analysis in membrane-mimetic media.

Hygromycin resistance gene cassettes for vector construction and selection of transformed rice protoplasts

Hygromycin resistance gene cassettes were designed to facilitate vector construction for plant transformation. Unique EcoRI, Pstl, and Sacll sites in the coding sequence of a hygromycin B phosphotransferase gene (hph) from Escherichia coli were eliminated. The mutated hph genes were used to form gene cassettes flanked by EcoRI-Sacll-Kpnl-Hindlll sites. Hygromycin resistance of wild-type and mutated hph genes was indistinguishable in E. coli and rice protoplast growth assay.