[The turn-over flap of the frontalis muscle used for eye-socket depression with contraction of the conjunctival capsule]

We were used to repair the eye-socket depression and contraction after eyeball loss with fat, dermis or rib cartilage implantation. This "stuffing method" has some disadvantages, including absorption and exposure of the implant. In recent years the authors have used a turn-over flap of the frontalis muscle to treat eye-socket depression with contraction of the conjunctival capsule. Satisfactory results have been found at postoperative follow-up.

Inhibition of progressing primary esophageal peristalsis by pharyngeal water stimulation in humans

BACKGROUND & AIMS

Sensory impulses initiated from the pharynx exert differing effects on the deglutitive apparatus. They have an inhibitory effect on the lower esophageal sphincter but an excitatory effect on the upper esophageal sphincter. The aim of this study was to systematically investigate the effect of pharyngeal sensory impulses evoked by water stimulation on the progressing esophageal peristalsis.

METHODS

Sixteen healthy young volunteers were studied in the supine position. The presence of normal peristalsis was verified. Esophageal peristalsis was recorded 3, 6, 9, 12, 15, and 18 cm above the lower esophageal sphincter. Pharyngeal stimulation was performed by injecting a predetermined threshold volume into the pharynx 2 cm above the upper esophageal sphincter, directed posteriorly. The injections were timed to coincide with the arrival of the peristaltic wave induced by dry swallows at respective recording sites.

RESULTS

Injection of the threshold volume (0.5 +/- 0.1 mL) stopped the progression of peristalsis at both the striated and smooth muscle esophagus. Topical pharyngeal anesthesia blocked this inhibitory effect (P < 0.01).

CONCLUSIONS

Sensory impulses initiated from the pharynx evoked by water injection inhibit the progression of primary esophageal peristalsis. Although the clinical significance of these findings is not determined, they may explain the mechanism of some of the failed esophageal peristalsis.

Activity of trovafloxacin (CP-99,219) against Legionella isolates: in vitro activity, intracellular accumulation and killing in macrophages, and pharmacokinetics and treatment of guinea pigs with L. pneumophila pneumonia

The activity of trovafloxacin against 22 clinical Legionella isolates was determined by broth microdilution susceptibility testing. The trovafloxacin concentration required to inhibit 90% of strains tested was < or = 0.004 micrograms/ml, in contrast to 0.032 micrograms/ml for ofloxacin. In guinea pig alveolar macrophages, trovafloxacin achieved intracellular levels up to 28-fold over the extracellular concentration, which was similar to the levels obtained with erythromycin. Trovafloxacin (0.25 micrograms/ml) reduced bacterial counts of two L. pneumophila strains grown in guinea pig alveolar macrophages by > 2 log10 CFU/ml, without regrowth, under drug-free conditions over a 3-day period; trovafloxacin was significantly more active than ofloxacin or erythromycin (0.25 to 1 microgram/ml) in this assay. Single-dose (10 mg of prodrug CP-116,517-27 per kg of body weight given intraperitoneally [i.p.], equivalent to 7.5 mg of trovafloxacin per kg) pharmacokinetic studies performed in guinea pigs with L. pneumophila pneumonia revealed peak serum and lung trovafloxacin levels to be 3.8 micrograms/ml and 5.0 micrograms/g, respectively, at 0.5 h and 4.2 micrograms/ml and 2.9 micrograms/g, respectively, at 1 h. Administration of a lower prodrug dose (1.4 mg of trovafloxacin equivalent per kg i.p.) gave levels in lung and serum of 0.4 microgram/g and 0.4 microgram/ml, respectively, 1 h after drug administration. The terminal half-lives of elimination from serum and lung were 0.8 and 1.1 h, respectively. All 15 infected guinea pigs treated for 5 days with CP-116,517-27 once daily (10 mg/kg/day i.p., equivalent to 7.5 mg of trovafloxacin per kg/day) survived for 10 days after antimicrobial therapy, as did all 15 guinea pigs treated with ofloxacin once daily (10 mg/kg/day i.p.) for 5 days. None of 13 animals treated with saline survived. In a second experiment with animals, trovafloxacin (1.4 mg/kg/day i.p. for 5 days) protected all 16 guinea pigs from death, whereas all 15 animals treated with saline died. Trovafloxacin is an effective antimicrobial agent against Legionella in vitro and in vivo, with the ability to concentrate in macrophages and kill intracellular organisms.

In-vitro activity of levofloxacin against clinical isolates of Legionella spp, its pharmacokinetics in guinea pigs, and use in experimental Legionella pneumophila pneumonia

The activities of levofloxacin and ofloxacin against 22 clinical legionella isolates was determined by microbroth dilution susceptibility testing. Growth inhibition of two Legionella pneumophila strains grown in guinea pig alveolar macrophages by levofloxacin, ofloxacin, or erythromycin was also determined. The drug concentrations required to inhibit 90% of strains tested was 0.032 mg/L for levofloxacin or ofloxacin, and was 0.016 mg/L for ciprofloxacin. BYE alpha broth significantly inhibited the activities of all three drugs tested, as judged by the susceptibility of control Escherichia coli strains. Levofloxacin (0.25 mg/L) reduced bacterial counts of two L. pneumophila strains grown in guinea pig alveolar macrophages by 1 log10, but regrowth occurred over a 3 day period; levofloxacin (1 mg/L) reduced bacterial counts by 2-3 log10 cfu/mL. Levofloxacin was significantly more active than erythromycin, and as active as ofloxacin or ciprofloxacin in this assay. Pharmacokinetic and therapy studies of levofloxacin and ofloxacin were performed in guinea pigs with L. pneumophila pneumonia. For the pharmacokinetic study, levofloxacin was given (10 mg/kg) by the intraperitoneal route to infected guinea pigs; mean peak plasma and lung concentrations were 3.4 mg/L and 1.4 micrograms/g, respectively, at 0.5 h and 2.6 mg/L and 0.6 micrograms/g at 1 h. The terminal half-life phase of elimination from plasma and lung was c. 1 h. All 15 infected guinea pigs treated with levofloxacin (10 mg/kg/day given ip once daily) for 5 days survived for 9 days after antimicrobial therapy, as did all 14 guinea pigs treated with the same dose of ofloxacin. None of 13 animals treated with saline survived. Levofloxacin is effective against L. pneumophila in vitro and in a guinea pig model of legionnaire's disease. Levofloxacin should be evaluated as a treatment of human legionnaires' disease.

Correlated flow cytometric analysis of H-ras p21 and DNA ploidy in acute myelogenous leukemia

The flow cytometric immunoassay was used to study the correlation between the H-ras oncogene product p21 and the DNA ploidy in 30 de novo cases of acute myelogenous leukemia (AML). The results showed that 17 cases were negative for p21 expression and 13 positive for p21. The patients with positive p21 had higher percentage of bone marrow and peripheral blasts and lower peripheral leukocyte count. The expression of p21 had no influence on the therapeutic effect. Before treatment, DNA diploidy occurred in 18 cases including 13 p21 negative ones, and DNA aneuploidy was revealed in 12 cases including 8 p21 positive ones. Patients with positive p21 or having aneuploidy in complete remission were at risk for early relapse. Our results suggest that p21 may be involved in the process of leukemogenesis and progression in AML.

Induction of immunotolerance in rats by intratesticular administration of an eicosapeptide of bovine S-antigen

Immunization of albino LEW rats with a retinal soluble antigen (S-antigen) induces experimental autoimmune uveoretinitis (EAU) which shows clinical features resembling those of human uveitis. Several uveitogenic epitopes have been identified in the antigen. This study reports that an intratesticular injection of low doses of a uveitogenic eicosapeptide (P343-362) of S-antigen prior to immunization with the same peptide prevented the onset of EAU by inducing systemic tolerance, designated orchidic tolerance. Splenic lymphocytes of both CD4+ and CD8+ subsets from tolerized rats transferred orchidic tolerance to syngeneic recipients and protected them from subsequent EAU induction. Orchidic tolerance elicited by low antigen dosage was mediated, in part, by active suppression due to suppressor or regulatory cells. At high antigen doses, however, regulatory activity was reduced possibly due to the induction of anergy in regulatory cells, and EAU severity increased. The CD4+ regulatory T cells from tolerized rats showed enhanced expression of IL-4 mRNA compared with CD4+ cells from control rats. Increased immunoreactivity for IL-4, IL-10 and TGF-beta was observed in the spleen and lymph nodes of tolerized animals. The results suggest that orchidic tolerance induced by low doses of P343-362 is mediated in part by CD4+ regulatory cells secreting Th2 cytokines.

Esophagopharyngeal distribution of refluxed gastric acid in patients with reflux laryngitis

BACKGROUND & AIMS

A variety of otolaryngological abnormalities have been attributed to the contact of gastroesophageal refluxate with respective structures of the aerodigestive tract. The aim of this study was to determine and compare the pharyngoesophageal distribution of gastric acid refluxate between patients with proven laryngitis attributed clinically to gastroesophageal reflux and three control groups.

METHODS

An ambulatory 24-hour simultaneous three-site pharyngoesophageal pH monitoring technique was used to measure reflux parameters in the pharynx, proximal esophagus, and distal esophagus.

RESULTS

Between-group comparison showed no significant difference in the reflux parameters in the distal esophagus between the studied groups. A significantly higher percentage of distal reflux episodes reached the proximal esophagus in the laryngitis group than in the control groups (P < 0.01), and the number of pharyngeal reflux episodes and time of acid exposure were significantly higher in the laryngitis group than in the control groups (P < 0.001).

CONCLUSIONS

Compared with normal controls and patients with gastroesophageal reflux disease, pharyngeal reflux of gastric acid is significantly more prevalent and the ratio of proximal to distal esophageal acid reflux episodes is significantly increased in patients with posterior laryngitis. Simultaneous three-site ambulatory pharyngoesophageal pH monitoring may provide supporting evidence when the diagnosis of reflux-induced aerodigestive tract lesions is considered.

Prostaglandin E2 contracts vascular smooth muscle and inhibits potassium currents in vascular smooth muscle cells of rat tail artery

There is evidence to suggest that PGE2 plays an important role in the regulation of vascular smooth muscle tone. To determine the cellular basis of this action, we studied the effect of PGE2 on force in helical muscle strips from rat tail artery. PGE2 evoked a sustained contractile response. The contractile response was concentration-dependent, with an EC50 value of 9.6 microM. Patch-clamp studies were conducted to investigate the effects of PGE2 on K channels in isolated vascular smooth muscle cells from rat tail artery. Current-clamp studies showed that PGE2 (1 microM) depolarized the membrane by 15.9 +/- 1.3 mV. Under voltage-clamp conditions, a voltage-dependent, delayed outward rectifier K current was generated by stepwise depolarization from a holding potential of -80 mV. The current, which was activated at -45 to -40 mV and showed almost no inactivation, was inhibited by 45% using 10 mM TEA. PGE2 inhibited the outward K current in a concentration-dependent manner, with EC50 values of 3.5 microM and 4.9 microM in primary and subcultured cells, respectively. The PGE2 receptor antagonist sodium meclofenamate abolished the PGE2-induced K current inhibition. Furthermore, the intracellular application of guanosine 5'-O(-)[2-thiodiphosphate] (GDP beta S), a G protein inhibitor, and pretreatment of the cells with cholera toxin prevented the PGE2-induced inhibition, whereas application of pertussis toxin did not.(ABSTRACT TRUNCATED AT 250 WORDS)

Scanning Kelvin Microscope: a new method for surface investigations

Based on the well known Kelvin probe for work function measurements a new microstructure analysis system - the Scanning Kelvin Microscope - has been developed. It allows to measure simultaneously with high lateral resolution the distribution of the contact potential difference (CPD) between a conductive sample and a reference probe together with the topographical structure of the sample surface. The measurement is contact free and non-destructive and can be carried out in natural environments. At present the lateral resolution of the measurement approaches 5 microm. The results can be displayed on a computer in three dimensional colour pictures.

Mechanisms of proton-induced stimulation of CGRP release from rat antrum

Mechanisms of acid-evoked CGRP release from gastric afferent nerves were investigated in rat antral mucosal/submucosal tissues. Low pH (pH 4.0, 5.0 and 6.0) stimulated antral CGRP release significantly and dose-dependently from rat antral fragments. Removal of extracellular calcium from the incubation medium resulted in significant inhibition (59%, P < 0.001) of acid (pH 4.0)-stimulated CGRP release. Conotoxin (1 x 10(-7) M), the selective blocker of N-type calcium channels, also significantly inhibited proton (pH 4.0)-induced CGRP release to values that were 74% below net stimulated levels. Neither nifedipine (1 x 10(-6) M), the L-type Ca(2+)-channel antagonist, nor indomethacin (1 x 10(-5) M), inhibitor of prostaglandin synthesis, altered acid-induced CGRP release. In contrast, ruthenium red (1 x 10(-5) M), capsaicin antagonist, almost completely prevented acid (pH 4.0)-stimulated CGRP release. Capsazepine (1 x 10(-4) M), a specific capsaicin receptor antagonist, also completely abolished acid-induced CGRP release. In conclusion, the results of these studies indicate that hydrogen ions are capable of evoking CGRP release from peripheral sensory neurons in rat antral mucosal/submucosal tissues. Proton-evoked CGRP release requires extracellular calcium and involves N-type calcium channels. Furthermore, acid appears to exert a capsaicin-like effect to evoke sensory neuropeptide release that is sensitive to capsazepine and ruthenium red. These data suggest that proton-induced antral CGRP release represents a direct action of hydrogen ions on mucosal/submucosal sensory dendritic nerve endings to effect local release of neuropeptide.

The structure of HIV-1 reverse transcriptase complexed with 9-chloro-TIBO: lessons for inhibitor design

BACKGROUND

HIV reverse transcriptase (RT) is a key target of anti-AIDS therapies. Structural studies of HIV-1 RT, unliganded and complexed with different non-nucleoside inhibitors (NNIs), have pointed to a common mode of binding and inactivation through distortion of the polymerase catalytic site by NNIs containing two hinged rings. The mode of binding of the TIBO family of inhibitors is of interest because these compounds do not fit the two-hinged-ring model.

RESULTS

The structure of HIV-1 RT complexed with 9-chloro-TIBO (R82913) has been determined at 2.6 A resolution. As reported for the lower resolution analysis of another TIBO compound, this inhibitor binds at the same site as other NNIs, but our higher resolution study reveals the Cl-TIBO is distorted from the conformation seen in crystals of the inhibitor alone. This allows Cl-TIBO to mimic the binding of NNIs containing two hinged rings. Inhibitor-protein interactions are again predominantly hydrophobic and the protein conformation corresponds to that seen in complexes with other tight-binding NNIs.

CONCLUSIONS

Although Cl-TIBO is chemically very different from other NNIs, it achieves remarkable spatial equivalence and shape complementarity with other NNIs on binding to RT. Comparison of the different RT-NNI complexes suggests modifications to the TIBO group of inhibitors which might enhance their binding and hence, potentially, their therapeutic efficacy.

Calcitonin gene-related peptide modulates acid-mediated regulation of somatostatin and gastrin release from rat antrum

BACKGROUND & AIMS

Acid has been shown to stimulate calcitonin gene-related peptide (CGRP) release from peripheral sensory afferent nerve endings in the stomach. The aim of this study was to determine whether endogenous CGRP was involved, by a neurocrine mechanism, in acid-mediated stimulation of somatostatin and inhibition of gastrin release.

METHODS

A two-compartment sleeve of antral mucosal/submucosal tissue was perfused to determine sensory nerve and endocrine cell responses to luminal acid. CGRP receptor antagonist, CGRP8-37, was used to inhibit the actions of endogenously released CGRP.

RESULTS

Perfusion of the antral sleeve lumen with media of increasing hydrogen ion concentration caused pH-dependent increases in CGRP and somatostatin release and decrease in gastrin release. CGRP8-37 inhibited significantly basal somatostatin (-36%) and stimulated basal gastrin (+65%) release (P < 0.02). Furthermore, CGRP8-37 administration prevented luminal acid-mediated inhibition of gastrin release and stimulation of somatostatin release. These results indicate that CGRP8-37 prevented acid-mediated feedback inhibition of gastrin release and acid-induced feedforward somatostatin release.

CONCLUSION

These results suggest that CGRP plays an important role in the response of antral D and G cells to luminal acid and that local effector action of endogenous CGRP participates in regulation of antral regulatory peptide secretion.

[Role of energy metabolism in nutrition management of critically ill patients]

Indirect calorimetric measurements were made with a MedGraphics Critical Care Monitor (CCM) desktop analysis system in the observation of critically ill and malnourished patient's energy expenditure. In 15 critically ill patients, predicted energy requirements based on 1.75 times BEE calculated by Harris-Benedict formula or corrected Harris-Benedict formula averaged 32.7% and 27.8% greater than metabolic expenditure measured by indirect calorimetry respectively. In the 20 unstressed malnourished patients, predicted energy requirements based on the Harris-Benedict (BEE) formula averaged 15% to 20% higher than metabolic expenditure measured by indirect calorimetry. When the critically ill patients' total energy intakes were 1.2 times resting energy expenditure, their nutritional state could be maintained in normal conditions. While the malnourished patients were provided with 1.5 x REE in energy intake, the malnourished state could be reversed. We believed that the critically ill and malnourished patients' energy expenditures are better measured than predicted and their nutritional regimens should be guided under the computerized indirect calorimetry.

Mechanism and timing of nasopharyngeal closure during swallowing and belching

The mechanism(s) of nasopharyngeal closure (NPC) and its temporal relationship with other biomechanical events during swallowing and belching were studied in seven healthy volunteers, aged 26-39 yr, by concurrent videoendoscopic, videofluoroscopic, and manometric technique. Analysis of the videoendoscopic recordings showed that deglutitive NPC consisted of elevation of the soft palate and adduction of the superior pharyngeal constrictor muscle. Videofluoroscopy identified only the palatal elevation clearly. During belching, however, only palatal elevation occurred. Deglutitive NPC ranged between 0.73 and 0.94 s (0.8 +/- 0.04 SE), with a tendency to be longer with larger swallowed volumes. Onset of NPC was identified earlier endoscopically than as seen fluoroscopically. Complete NPC preceded the arrival of barium bolus into the pharynx, and this pattern was seen for all volumes tested. Manometric onset of upper esophageal sphincter (UES) relaxation was seen before the onset of NPC, but the physical opening of the UES as seen fluoroscopically occurred after complete closure of the nasopharynx. We conclude the following: 1) The mechanism of NPC during swallowing and belching is different. During swallowing, NPC has two tiers of closure, palatal elevation and superior pharyngeal muscle adduction; during belching only palatal elevation occurs. 2) NPC is tightly coordinated with other biomechanical events during swallowing and belching.

Deglutitive aspiration in patients with tracheostomy: effect of tracheostomy on the duration of vocal cord closure

BACKGROUND/AIMS

Deglutitive aspiration in patients with tracheostomy has been attributed to impaired laryngeal movement, loss of protective laryngeal reflexes, and uncoordinated laryngeal closure. The aim of this study was to determine the effect of tracheostomy on the duration of deglutitive vocal cord closure.

METHODS

Using concurrent videoendoscopy, respirography, and submental electromyography, deglutitive vocal cord closure and its temporal relationship with deglutitive apnea was compared between patients with tracheostomy and normal volunteers.

RESULTS

Between-group comparison showed that the duration of vocal cord adduction/abduction in patients with tracheostomy was significantly shorter than that of normal volunteers (P < 0.05). Contrary to normal volunteers, in patients with tracheostomy, 5-mL water swallows significantly increased the duration of vocal cord adduction/abduction compared with that of dry swallows (P < 0.05). In addition, in patients with tracheostomy, deglutitive apnea and submental electromyography were not coordinated with vocal cord kinetics.

CONCLUSIONS

Although the vocal cords close completely during swallowing in patients with tracheostomy, their duration of closure is significantly shorter compared with normal volunteers. Coordination of deglutitive vocal cord kinetics, apnea, and submental electromyography is altered in patients with tracheostomy. Contrary to normal controls, duration of deglutitive vocal cord closure in patients with tracheostomy is modified by the presence of liquid bolus.

Effect of aging on the secondary esophageal peristalsis: presbyesophagus revisited

In this study we determined the effect of aging on the capability of the human esophagus to generate secondary peristalsis. We studied nine healthy young (35 +/- 2 yr, 25-45 yr) and nine healthy elderly (74 +/- 3 yr, 70-83 yr) volunteers. We stimulated secondary peristalsis by intraesophageal air injection and balloon distension. All young volunteers exhibited secondary esophageal peristalsis. In four elderly volunteers, secondary peristalsis could not be elicited with injection of any of the tested air volumes. Frequency of stimulation of secondary peristalsis and lower esophageal sphincter (LES) relaxation in response to intraesophageal air distension in the elderly was significantly lower than that in the young (P < 0.01). Stimulation of secondary peristalsis by balloon distension was less consistent compared with the air injection. In conclusion, 1) in the elderly, compared with the young, secondary esophageal peristalsis is either absent or is evoked less frequently after esophageal distension, and complete LES relaxation in response to esophageal air distension is less frequent, and 2) in both young and elderly, secondary esophageal peristalsis is induced more frequently after generalized esophageal distension by air than its segmental distension by a balloon.

High resolution structures of HIV-1 RT from four RT-inhibitor complexes

We have determined the structures of four complexes of HIV-1 reverse transcriptase with non-nucleoside inhibitors, three fully refined at high resolution. The highest resolution structure is of the RT-nevirapine complex which has an R-factor of 0.186 and a root-mean-square bond length deviation of 0.015 A for all data to 2.2 A. The structures reveal a common mode of binding for these chemically diverse compounds. The common features of binding are largely hydrophobic interactions and arise from induced shape complementarity achieved by conformational rearrangement of the enzyme and conformational/configurational rearrangement of the compounds.

Mechanism of inhibition of HIV-1 reverse transcriptase by non-nucleoside inhibitors

The structure of unliganded HIV-1 reverse transcriptase has been determined at 2.35 A resolution and refined to an R-factor of 0.219 (for all data) with good stereochemistry. The unliganded structure was produced by soaking out a weak binding non-nucleoside inhibitor, HEPT, from pregrown crystals. Comparison with the structures of four different RT and non-nucleoside inhibitor complexes reveals that only minor domain rearrangements occur, but there is a significant repositioning of a three-stranded beta-sheet in the p66 subunit (containing the catalytic aspartic acid residues 110, 185 and 186) with respect to the rest of the polymerase site. This suggests that NNIs inhibit RT by locking the polymerase active site in an inactive conformation, reminiscent of the conformation observed in the inactive p51 subunit.

Purification and properties of a Golgi-derived (alpha 1,2)-mannosidase-I from baculovirus-infected lepidopteran insect cells (IPLB-SF21AE) with preferential activity toward mannose6-N-acetylglucosamine2

Because the availability and subcellular distribution of processing mannosidases in cells play such powerful roles in determining ultimate structures of glycoconjugates, we desired to identify, characterize, and investigate possible regulation of mannosidases in infected and noninfected lepidopteran insect cells. Since our previous observations that a mannosidase activity that converted Man6GlcNAc2 to Man5GlcNAc2 was enhanced in virus-infected cells, thus providing the necessary intermediate for further processing to complex-type oligosaccharides, we attempted purification of this enzyme. A mannosidase was isolated and purified from membranes, operationally defined as Golgi, of recombinant baculovirus-infected Spodoptera frugiperda (IPLB-SF-21AE) cells. The molecular mass of this protein was approximately 63 kDa. Assays performed by measuring the conversion of NaB3H4-reduced Man6GlcNAc2-ol to Man5GlcNAc-[3H]GlcNAc2-ol demonstrated that the mannosidase activity was dependent on the presence of divalent cations, which was optimal for Ca2+ at pH 6.0. Inclusion of 1-deoxymannojirimycin resulted in 50% inhibition at a concentration of 20 microM, whereas swainsonine did not show such inhibition. No activity was observed with p-nitrophenyl alpha-D-mannoside (4 mM) as a substrate. The preferred reduced oligosaccharide substrate was Man6GlcNAc2-ol, with lower activities obtained with Man9GlcNAc2-ol, Man8GlcNAc2-ol, and Man7GlcNAc2-ol. With Man6GlcNAc2-ol as substrate, products smaller than reduced Man5GlcNAc2-ol were not observed. Mannose was also liberated from the glycoprotein, ovalbumin. These properties are consistent with an enzyme classification as a type I (alpha 1,2)-Man6-mannosidase.

Inhibition of resting lower esophageal sphincter pressure by pharyngeal water stimulation in humans

BACKGROUND/AIMS

Normal inhibition of lower esophageal sphincter (LES) tone occurs during swallowing and belching. However, it is known that it may occur independently of these functions. The aim of this study was to characterize the effect of pharyngeal water stimulation on resting LES pressure.

METHODS

The effect of rapid-pulse and slow continuous intrapharyngeal injection of minute increments of water on the resting tone of the upper and LES of 14 healthy young volunteers was evaluated by concurrent manometry, submental electromyography, and respirography.

RESULTS

At a threshold volume, pharyngeal water injection induced an isolated LES relaxation in all volunteers. The threshold volume inducing LES relaxation by rapid-pulse injection, 0.16 +/- 0.01 mL, was significantly lower than that with slow continuous injection (0.5 +/- 0.05 mL) (P < 0.05). The duration and magnitude of LES relaxation were not volume dependent. The duration of LES relaxation induced by rapid-pulse injection was significantly longer than that of swallows.

CONCLUSIONS

Minute amounts of liquid injected into the pharynx induce LES relaxation different from that of the normal swallow. Neither the duration nor the magnitude of this relaxation is volume dependent. Whereas the contribution of this finding to the mechanism of transient LES relaxation remains to be ascertained, it may partially explain the variability of the basal LES pressure.

Transparent gasbag tie-over for persistent pressure and inspection in free skin grafting

A simple tie-over dressing using a transparent gasbag, which has been used successfully in skin grafting on rabbits and human beings, allows objective pressure survey and subjective direct inspection of the underlying grafted skin. Moreover, if hematoma or any other complication is recognized, the gasbag can be deflated and removed, being reapplied after the hematoma is expressed or the complication is treated.

The simulation of urban system dynamics in Atlantic Canada, 1951-1991

"A dynamic urban model is used to study the post-war evolution of the Atlantic Canada urban system. The computer-based simulation model is calibrated for the period 1951-86 and then employed to predict the 1991 population of each CMA and CA within the system. The simulation results show that, to a large extent, the evolution of the system can be understood in terms of endogenous system dynamics rather than exogenous events. Specifically, competition among the cities of the region is a significant factor in the urban system evolution. The high degree of abstraction of the model means that data requirements for application are minimal, and the calibration procedure is relatively simple. The successful predictions show that the model can yield useful results in spite of its simplicity." (SUMMARY IN FRE)

[Effects of over feeding on the energy expenditure and substrates oxidative rate in surgical patients]

In this study, computerized indirect calorimetric measurements were made using a medical graphics critical care monitor (CCM) desktop analysis system in the observation of metabolic state of 20 patients complicated with external gastrointestinal fistula. While these malnourished patients were provided with 1.5 x REE in total energy intake, the malnutrition state could be reversed. But with 1.75 or 2.0 x REE or up total energy intake, the general nutritional state could not be improved faster, the O2 consumption and CO2 production and energy expenditure increased, while the net glucose oxidation increased and net lipid oxidation decreased or net lipogenesis occurred simultaneously. We believed that superfluous energy intake is harmful to critically ill patients and may lead to cell injury and dysfunction.

Additive effect of contractions and insulin on GLUT-4 translocation into the sarcolemma

The maximal effects of insulin and muscle contractions on glucose transport are additive. GLUT-4 is the major glucose transporter isoform expressed in skeletal muscle. Muscle contraction and insulin each induce translocation of GLUT-4 from intracellular sites into the plasma membrane. The purpose of this study was to test the hypothesis that the incremental effect of contractions and insulin on glucose transport is mediated by additivity of the maximal effects of these stimuli on GLUT-4 translocation into the sarcolemma. Anesthetized rats were given insulin by intravenous infusion to raise plasma insulin to 2,635 +/- 638 microU/ml. The gastrocnemius-plantaris-soleus group was stimulated to contract via the sciatic nerve by using a protocol that maximally activates glucose transport. After treatment with insulin, contractions, or insulin plus contractions or no treatment, the gastrocnemius-plantaris-soleus muscle group was dissected out and was subjected to subcellular fractionation to separate the plasma membrane and intracellular membrane fractions. Insulin induced a 70% increase and contractions induced a 113% increase in the GLUT-4 content of the plasma membrane fraction. The effects of insulin and contractions were additive, as evidenced by a 185% increase in the GLUT-4 content of the sarcolemmal fraction. This finding provides evidence that the incremental effect of maximally effective insulin and contractile stimuli on glucose transport is mediated by additivity of their effects on GLUT-4 translocation into the sarcolemma.

Developmental regulation of beta-galactoside alpha 2,6-sialyltransferase in small intestine epithelium

A striking biochemical alteration to the epithelium of the small intestine upon weaning is the loss of microvillar sialic acids. Antibody and cDNA probes to the beta-galactoside alpha 2,6-sialyltransferase (SiaT-1, EC 2.4.99.1) were used to characterize the expression of this sialyltransferase in the small intestine of suckling rats. SiaT-1 mRNA and protein in the intestinal epithelium are rapidly lost upon weaning, in agreement with the loss of mucosal sialic acids and general sialyltransferase activity. Developmental repression of SiaT-1 is manifested in a proximal to distal gradient; SiaT-1 mRNA and protein are lost first from the duodenum and persist the longest in the ileum. We have previously documented that SiaT-1 gene expression can be transcriptionally initiated from a number of distinct tissue-specific promoter regions. Here, by criteria of mRNA mobility on agarose gels, primer extension analysis, and differential Northern hybridization, we show that the promoter previously considered to be liver-specific is operative in SiaT-1 expression in the small intestine of suckling animals. Comparison of this SiaT-1 promoter region with promoter regions of other genes exhibiting dual intestine-hepatic tissue specificity revealed a number of striking sequence similarities. Regulatory implications and consequences of small intestinal SiaT-1 expression in suckling but not in weaned animals are discussed.

Effect of aging, position, and temperature on the threshold volume triggering pharyngeal swallows

BACKGROUND/AIMS

Swallows triggered by direct stimulation of pharyngeal structures may help to prevent aspiration by emptying the pharynx. The aims of this study were to compare the biomechanical events of the pharyngeal and primary swallow, determine the threshold volume of liquid required to trigger the pharyngeal swallows, and determine the effect of aging, position, and temperature on this threshold volume.

METHODS

Concurrent manometry, video fluoroscopy, and video endoscopy were used to study young and elderly healthy volunteers.

RESULTS

During pharyngeal swallows, in contrast to primary swallows, the free portion of the tongue did not make contact with the hard palate. In addition, pharyngeal swallows did not result in oral bolus clearance. All other biomechanical events, including deglutitive glottal function, were similar in both types of swallows. The threshold volume for pharyngeal swallows in young volunteers was significantly smaller than in the elderly (P < 0.01). Temperature and position did not have significant effects on threshold volume.

CONCLUSIONS

Swallowing is readily induced by water stimulation of the pharynx. Pharyngeal swallows do not induce lingual peristalsis or clearance of oral content. The threshold volume of the pharyngeal swallow is significantly higher in the elderly than in the young, but it is not affected by body position or bolus temperature.

[Establishment of immuno-PCR technique for the detection of tumor associated antigen MG7-Ag on the gastric cancer cell line]

The gastric cancer associated antigen McAb MG7-Ag was detected by means of a newly established method, termed immuno-PCR. A McAb-recombinant DNA chimeric molecule was made which possesses bispecific binding affinity for antigen that had been immobilized on microtiter wells and the segment of the attached DNA was amplified by PCR. The antigen of gastric cancer cell line KATO III was monitored by this method. Analysis of PCR products by agarose gel electrophoresis after staining with ethidium bromide allowed as few as 20 cells to be detected readily and reproducibly. Immuno-PCR showed a 10(4) enhancement in detection sensitivity compared with ELISA assay. When the same numbers of cells (2 x 10(6)/ml) were immobilized and then the serial diluted chimeric molecule was added, 3.8 x 10(-14) moles and 3.0 x 10(-11) moles were needed to give positive results with the immuno-PCR and ELISA assay, respectively. Therefore, immuno-PCR could give an enormous amplification capability with good specificity, and has a sensitivity much higher than any existing techniques for antigen detection.

Chemical studies of Chinese licorice-roots. I. Elucidation of five new flavonoid constituents from the roots of Glycyrrhiza glabra L. collected in Xinjiang

From the air-dried roots of Glycyrrhiza glabra L. (Leguminosae) collected in Xinjiang province, China ("Shinkyo-Kanzo" in Japanese), five new flavonoid compounds named glucoliquiritin apioside (1) (a flavonone bisdesmoside), prenyllicoflavone A (5) (a bisprenylflavone), shinflavone (7) (a prenylated pyranoflavanone), shinpterocarpin (9) and 1-methoxyphaseollin (12) (both pyranopterocarpans), were isolated together with eight known saponins, seven known flavonoid glycosides, and eleven flavonoids. The structures of the new compounds have been elucidated on the basis of their chemical and physicochemical properties.

Presynaptic muscarinic receptors modulate acetylcholine release from rat antral mucosal/submucosal nerves

The purpose of the present studies was to determine whether autoinhibition of acetylcholine release could be demonstrated in vitro from mucosal/submucosal neurons in rat antrum. Rat antral mucosal/submucosal tissues preloaded with [3H]choline were perifused and [3H]acetylcholine release measured under basal and stimulated conditions. Carbachol inhibited both spontaneous and evoked (electrical field stimulation, KCl) acetylcholine release from rat antral tissues: 1 x 10(-5) M carbachol inhibited basal [3H]ACh release maximally to -38.2 +/- 3.1% (P < 0.001 vs control). The nonselective muscarinic antagonist atropine enhanced both basal and stimulated acetylcholine release and abolished carbachol-induced inhibition of acetylcholine release. Pirenzepine, a muscarinic M1 receptor antagonist, inhibited acetylcholine release and did not alter carbachol-induced inhibition of acetylcholine release. In conclusion, acetylcholine release from rat antral mucosal/submucosal neurons is regulated negatively by a presynaptic feedback mechanism involving M2 and/or M3 receptors, while presynaptic M1 receptors facilitate release of neurotransmitter.

Evidence that prostaglandin E2 can block calcium-activated 86Rb efflux from rat brain synaptosomes via a protein kinase C-dependent mechanism

The effects of prostaglandin E2 (PGE2) on 86Rb efflux from rat brain synaptosomes were studied to explore its role in nerve ending potassium (K+) channel modulation. A selective dose-dependent inhibition of the calcium-activated charybdotoxin-sensitive component of efflux was found upon application of PGE2. No significant effect was seen on basal and voltage-dependent components over the concentration range of 10(-8) to 10(-5) M. The protein kinase C (PKC) inhibitors H-7 (10 microM) and staurosporine (100 nM), as well as prolonged preincubation (90 min) with 4 beta-phorbol 12,13-dibutyrate, which has been reported to down-regulate PKC, abolished the PGE2-induced inhibition, whereas HA1004 (10 microM) and Rp-3',5'-cyclic phosphorothioate (100 nM), which are relatively more selective for protein kinase A than PKC, did not. 4 beta-Phorbol 12,13-dibutyrate (100 nM), an activator of PKC, produced a similar inhibition of the Ca(2+)-dependent component of 86Rb efflux but also had no effect on the basal and voltage-dependent components. These data suggest that PGE2 can inhibit rat brain nerve ending calcium-activated 86Rb efflux, and this inhibition may involve PKC activation.

Inhibition of a K+ current by beta-dendrotoxin in primary and subcultured vascular smooth muscle cells

beta-Dendrotoxin (beta-DTX), a polypeptide component of Eastern Green Mamba snake venom, inhibits a slow voltage-activated 86Rb efflux from synaptosomes, suggesting that beta-DTX inhibits K+ channels. The effects of beta-DTX on the K+ currents in primary cultured and subcultured (passages 8-12) rat tail artery vascular smooth muscle cells (VSMCs) were studied using the whole-cell patch-clamp technique. A delayed rectifier K+ current was observed in both types of cells. The current, which was relatively insensitive to tetraethylammonium, was activated at -40 to -30 mV and showed almost no inactivation. beta-DTX (1-1000 nM) decreased the outward K+ current. The effect was concentration dependent and reversible by washout but did not depend on the frequency of stimulation (use dependence) or the membrane potential. beta-DTX was more effective in primary cultured cells than in subcultured cells. K+ channels in primary cultured cells were maximally (45%) inhibited by 1 microM beta-DTX compared with 35% inhibition in subcultured cells. The concentration producing half-maximal inhibition was 5.1 x 10(-8) M for primary cells and 7.1 x 10(-8) M for subcultured cells. The delayed rectifier current was not affected by alpha-DTX, a blocker of the fast-inactivating outward K+ current (IA). These results clearly demonstrate that beta-DTX is a novel antagonist of the delayed rectifier K+ current in primary and subcultured rat tail artery VSMCs.

The N-glycosidase mechanism of ribosome-inactivating proteins implied by crystal structures of alpha-momorcharin

BACKGROUND

alpha-Momorcharin (alpha MMC) is a type I ribosome-inactivating protein. It inhibits protein synthesis by hydrolytically removing a specific adenine residue from a highly conserved, single-stranded loop of rRNA.

RESULTS

Here we describe the determination and refinement of the crystal structures of alpha MMC in the native state and in complexes with the product, adenine, and a substrate analogue, formycin 5'-monophosphate (FMP) at high resolution. Both adenine and the base of FMP are tightly bound; the ribose of bound FMP adopts a strained, high-energy conformation, which may mimic the structure of the transition state.

CONCLUSIONS

These structures indicate that residues Tyr70, Glu160 and Arg163 of alpha MMC are the most critical for catalysis. We propose that the strained conformation of the ribose in the target adenosine weakens the glycoside bond. Partial protonation mediated by Arg163 then facilitates N-glycoside bond cleavage, leading to the formation of an oxycarbonium ion intermediate which is stabilized by the negatively-charged Glu160. Tyr70 adopts subtly different conformations in the three structures implying that it may be important in substrate recognition and perhaps catalysis.

Identification and characterization of the esophagoglottal closure reflex in a feline model

To identify a suitable animal model and to delineate the neural pathway and target organs of the esophagoglottal closure reflex we studied three species. Study showed the existence of an esophagoglottal closure reflex in cats. The presence of this reflex could not be documented in the opossum. In monkeys, because of the inadequacy of the available recording devices, its presence could not be ascertained. In the feline model, the closure response of the vocal folds to the abrupt generalized and segmental distension of the esophagus was similar to that of the humans. Study findings indicate that among glottal adductor muscles at least interarytenoid and lateral cricoarytenoid muscles are involved as target organs of the esophagoglottal closure reflex. Decerebration did not change the frequency of glottal closure response to esophageal distension, supporting the notion that this reflex is completely under brain stem control. Bilateral cervical vagotomy abolished the glottal closure induced by esophageal distension indicating that this reflex is mediated by the vagus nerve. Upper esophageal sphincter (UES) pressure response to esophageal distension by air was variable, suggesting that glottal and UES response to esophageal distension, although closely coordinated, are not dependent on one another. In summary, an esophagoglottal closure reflex exists in feline species, and many similarities in the elicitation and mediation of this reflex have been found with that of humans. This model could be used for further physiological studies.

Alpha-lactalbumin possesses a distinct zinc binding site

It has been proposed that the binding of Zn2+ to alpha-lactalbumin switches the conformation to one akin to a state intermediate in the folding of the protein. However, the high resolution x-ray crystal structure of human alpha-lactalbumin-Zn2+ complex at 1.7-A resolution (pH 7.6) does not reveal any significant change in conformation from the native state. The Zn2+ ion binds specifically in the "cleft" of alpha-lactalbumin (the region which forms the active site of the homologous protein lysozyme). This may suggest a possible role for Zn2+ binding in lactose synthase complex. The coordination of the Zn2+ ion involves a symmetry-related molecule in the crystal, the crystal contacts being stabilized by a SO4(2-) ion bound at the interface between three molecules.

Saponin and sapogenol. L. On the constituents of the roots of Glycyrrhiza uralensis Fischer from Xinjiang, China. Chemical structures of licorice-saponin L3 and isoliquiritin apioside

From the air-dried roots of Glycyrrhiza uralensis Fischer collected in Xinjiang province, China ("Shinkyo-Kanzo" in Japanese), a new oleanene-type triterpene oligoglycoside named licorice-saponin L3 and a new chalcone oligoglycoside named isoliquiritin apioside were isolated together with glycyrrhizin, 18 alpha-glycyrrhizin, apioglycyrrhizin, araboglycyrrhizin, licorice-saponins A3, E2, G2, and H2, and six known flavonoid glycosides. On the basis of chemical and physicochemical evidence, the structures of licorice-saponin L3 and isoliquiritin apioside were elucidated as 3 beta-[alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyranosyl(1--> 2)-beta-D-glucuronopyranosyloxy]-22 beta-acetoxy-24-hydroxyolean-12-en-30-oic acid (1) and 4-O-[beta-D-apiofuranosyl(1-->2)-beta-D- glucopyranosyl]isoliquiritigenin (6), respectively.

Saponin and sapogenol. XLIX. On the constituents of the roots of Glycyrrhiza inflata Batalin from Xinjiang, China. Characterization of two sweet oleanane-type triterpene oligoglycosides, apioglycyrrhizin and araboglycyrrhizin

Two sweet oleanane-type triterpene oligoglycosides named apioglycyrrhizin and araboglycyrrhizin were isolated from the air-dried roots of Glycyrrhiza inflata Batalin, collected in Xinjiang province (Shinkyo-Kanzo in Japanese), together with glycyrrhizin (3), licorice-saponins A3 (8), G2 (10), and H2 (11) and known flavonoid glycosides. On the basis of chemical and physicochemical evidence, the structures of apioglycyrrhizin and araboglycyrrhizin have been determined to be expressed as 3-O-[beta-D-apiofuranosyl(1-->2)-beta-D- glucuronopyranosyl]glycyrrhetic acid (1) and 3-O-[alpha-L- arabinopyranosyl(1-->2)-beta-D-glucuronopyranosyl]glycyrrhet ic acid (2), respectively. During the course of these studies, it has been found that the hydroxyl groups in the oligosaccharide moiety of the glucuronide saponins may be partially methylated by prolonged treatment with diazomethane in methanol. The sweetness of the saponins hitherto isolated from various Glycyrrhizae Radix has been examined and a structure-sweetness relationship, as compared with glycyrrhizin, has been found.

Effect of age and bolus variables on the coordination of the glottis and upper esophageal sphincter during swallowing

We studied 1) the effect of age and bolus variables on a) the coordination of deglutitive vocal cord adduction and upper esophageal sphincter (UES) relaxation and b) the duration of deglutitive vocal cord adduction; 2) the effect of the presence of a manometric catheter across the UES on the deglutitive glottal function; and 3) the temporal relationship between deglutitive vocal cord closure and swallow-induced apnea. We studied 10 young (23 +/- 2 yr) and 10 healthy elderly (73 +/- 2 yr) volunteers by concurrent videoendoscopy, UES manometry, respirography, and submental surface electromyography. In both groups the onset of vocal cord adduction preceded the onset of UES relaxation, deglutitive apnea, and submental electromyogram swallowing signal. In both groups, bolus volume and temperature did not have any significant effect on the duration of deglutitive vocal cord adduction. In both young and elderly volunteers, water swallows, compared with dry swallows, significantly shortened the interval between the onset of deglutitive vocal cord adduction and the onset of UES relaxation. In conclusion, coordination between deglutitive glottal and UES function, as well as the duration of deglutitive vocal cord adduction, is preserved in the elderly. Bolus volume and temperature do not have a modulatory effect on the duration of vocal cord closure, but water swallow shortens the interval between the onset of glottal closure and UES relaxation. This shortened interval may contribute to the safety of the airway during swallowing of liquid volumes.

Retinal detachment and degeneration in response to subretinal perfluorodecalin in rabbit eyes

Perfluorocarbon liquids, including perfluorodecalin (PFD), are useful intraoperative tools in complicated vitreoretinal surgery, such as for giant retinal tears, PVR and intraocular foreign bodies. Due to its high specific gravity (1.91 g/cm3) subretinal complications of PFD may occur. The consequences of subretinal PFD were studied in 23 albino rabbits (28 eyes). Using glass micropipettes (outer diameter of tip 100-120 microns), we injected 50-100 microliters PFD subretinally via the vitreous space. The same volume of BSS was injected into 18 control eyes. Eyes were monitored by indirect ophthalmoscopy and examined by light and electron microscopy at 1, 2 and 3 days, and 1, 2, 4 and 12 weeks. Progressive retinal detachments with newly formed retinal breaks in the inferior quadrants developed in 26 of 28 eyes. As early as 1 day postoperatively, subretinal PFD induced loss of outer and inner segments. Local retinal necrosis occurred in 4 eyes 5-7 days after surgery. A marked vacuole formation in retinal layers and PFD emulsification were regularly seen. The control eyes healed spontaneously. Toxic, mechanical and barrier effects may have caused the retinal damage. We advocate that all PFD be removed from the eye at surgery.

Effect of aging and bolus variables on pharyngeal and upper esophageal sphincter motor function

Effect of aging, bolus volume, temperature, and consistency on the pharyngeal peristalsis, as well as the effect of aging on the upper esophageal sphincter (UES) resting pressure and its response to esophageal distension by air and balloon, were studied in 14 young and 12 healthy elderly volunteers. In both age groups there was no significant volume or temperature effect on amplitude, duration, or velocity of the pharyngeal peristalsis. Compared with water swallows, mashed potato swallows resulted in a significant increase in the amplitude and duration of the hypopharyngeal peristaltic pressure wave (P < 0.05). For water swallows, the amplitude and duration of the peristaltic pressure wave in the hypopharynx were significantly increased in the elderly compared with the young group (P < 0.01). UES resting pressure in the elderly measured 43 +/- 5 (SE) mmHg and was significantly less than that of the young (71 +/- 8 mmHg; P < 0.01). Magnitude of the UES pressure decrease because of esophageal distension by air, as well as magnitude of its pressure increase because of esophageal balloon distension, was similar among young and elderly. 1) Contrary to common expectations, the parameters of the pharyngeal peristaltic pressure wave do not deteriorate in the elderly in their seventh and eighth decade. 2) Compared with the young, hypopharyngeal pressure wave amplitude and duration are significantly increased in the elderly. This increase could be caused by an adaptation response to a pharyngeal outflow compromise. 3) Pharyngeal peristaltic pressure wave amplitude and duration, but not its velocity, are modulated by the bolus consistency. This modulatory mechanism is preserved in the elderly. 4) Although UES resting pressure is significantly decreased in the elderly, its pressure response to esophageal distension by air and balloon is preserved.

Determinants of intrabolus pressure during esophageal peristaltic bolus transport

Previous manometric studies of esophageal fluid bolus transport in humans have generally ignored the hydrodynamic distinction between intrabolus pressure and pressure within the lumen-occluded, contracting esophageal segment. In this study we obtained concurrent esophageal videofluoroscopic and intraluminal manometric recordings in supine normal volunteers using different bolus volumes and viscosities and abdominal compression. Intrabolus pressure increased with bolus volume, viscosity, and abdominal compression. Esophageal diameter increased with larger bolus volumes, and this increase was correlated with increases in intrabolus pressure. Intrabolus pressure was highest in the bolus tail. Peak intraluminal pressures > 20 mmHg above basal intrabolus pressure almost invariably were associated with effective peristalsis, whereas values of this pressure differential < 20 mmHg frequently were associated with ineffective peristalsis and retrograde bolus escape. Intrabolus pressure can serve as an important indicator of the forces resisting peristaltic transport and the occurrence of ineffective bolus transport.

Calcitonin gene-related peptide mediates capsaicin-induced neuroendocrine responses in rat antrum

BACKGROUND

Calcitonin gene-related peptide (CGRP) is a 37-amino acid peptide localized to primary sensory afferent nerves in the rat stomach. The actions of CGRP in regulating antral neuroendocrine function were examined in vitro through the use of capsaicin, an agent capable of evoking neuropeptide release from peripheral sensory nerve endings. These results were compared with the effects of exogenous CGRP and CGRP antagonist, CGRP8-37.

METHODS

Rat antral mucosal/submucosal fragments were incubated in either static or dynamic perifusion experiments. Media were assayed for gastrin, somatostatin, CGRP, and acetylcholine.

RESULTS

Capsaicin, like exogenous CGRP, stimulated antral somatostatin release and inhibited both gastrin release and acetylcholine discharge. Low dose capsaicin (1 x 10(-5) mol/L) caused significant stimulation of CGRP release: 33 +/- 0.2 vs. 14 +/- 1 pg/mL protein; P < 0.001. Tetrodotoxin blocked capsaicin-induced inhibition of acetylcholine release and prevented partially capsaicin-mediated stimulation of CGRP release. The CGRP receptor antagonist CGRP8-37 prevented capsaicin-induced D-cell stimulation and inhibition of G-cell secretion and cholinergic discharge.

CONCLUSIONS

The effects of capsaicin-induced changes in antral D- and G-cell secretion and acetylcholine discharge are due primarily to release of CGRP. Antral CGRP release from primary sensory afferent nerve terminals may act as a local effector substance to regulate antral neuroendocrine function.

[Enhanced malignancy of tumor cells by the interaction with host cells reactive to foreign body]

We examined factors promoting malignant progression using a weakly malignant variant cell line, ER-1, derived from c-SST-2, a rat mammary carcinoma. ER-1 cells were converted to a highly malignant phenotype (highly tumorigenic, metastatic, invasive in vitro) by the in vitro/in vivo interaction with host cells reactive to foreign body. Epidermal growth factor (EGF) and transforming growth factor-beta (TGF-beta) produced by host reactive cells, transiently enhanced the tumorigenicity and in vitro invasiveness of ER-1 cells into an endothelial cell monolayer. The host reactive cells also produced oxygen radicals and induced mutations in ER-1 cells. It is speculated that mutations induced by host reactive cells cause cellular diversification, including the emergence of highly malignant variant cells whose growth is selectively promoted by growth factors such as EGF and TGF-beta.

Effects of some tricyclic psychopharmacons and structurally related compounds on motility of Proteus vulgaris

A simple test for the evaluation of drugs interfering with bacterial motility was established with Proteus vulgaris. With this model, promethazine, 7-hydroxy-chlorpromazine, imipramine, 7,8-dioxochlorpromazine and acridine orange were shown to exert significant motility and swarming inhibitory action on Proteus vulgaris strains at subinhibitory concentrations. Quinidine enhanced the antimotility effect of promethazine. The antimotility effect of promethazine was synergized by proton pump inhibitors omeprazole and abscissic acid, but antagonized by extracellular potassium and sodium ions.

Coordination of deglutition and phases of respiration: effect of aging, tachypnea, bolus volume, and chronic obstructive pulmonary disease

The effects of aging, tachypnea, bolus volume, and chronic obstructive pulmonary disease on the coordination of swallowing with the phases of respiration were studied by concurrent respirography and submental surface electromyography. Study findings showed that in young healthy volunteers, during rest, there is preferential coupling of subconscious swallowing with the expiratory phase of continuous respiration. This preferential coupling of swallowing with expiration was found to increase relative to other phases of respiration during water swallows and tachypnea (P < 0.05). Respiratory phase occurrence of swallowing and postdeglutitive resumption of respiration during exacerbation of chronic obstructive pulmonary disease was found to be significantly different compared with the basal state (P < 0.05). Respiratory phase occurrence of subconscious swallowing in the elderly was found to be different from the young (P < 0.05). Position had no significant effect on the coordination of swallowing and phases of respiration. We concluded that in resting young volunteers the majority of deglutitions are coupled with the expiratory phase of swallowing. This coupling is increased in frequency by the presence of a liquid bolus and tachypnea. And finally, age and chronic obstructive pulmonary disease alter this coordination significantly.