The action of adrenergic substances on the smooth muscle of the rat trachea

Adrenalin and noradrenaline first induced an increase in the trachea smooth muscle response with its subsequent decline in rats. Phentolamine decreases the muscle responses in its thoracic part and practically does not affect it in the cervical segments. The adrenergic neural fibres seem to terminate at the smooth muscle cells and the neurons of intramural ganglia.     

Immunohistochemical localisation of alpha1B-adrenergic receptors in the rat iris

This article reports results from a meta-analysis on adult age differences in the negative priming effect (21 studies on identity negative priming and 8 on location negative priming). Both younger and older adults were found to be susceptible to the negative priming effect in identity and location tasks. Effect sizes were homogeneous for both tasks, indicating that the data are adequately described without reference to moderator variables. State trace analysis on identity tasks, in which mean latencies in negative priming conditions were regressed onto mean latencies in baseline conditions, showed (a) that in both age groups the negative priming effect is proportional rather than additive and (b) that the negative priming effect is smaller in older adults as compared with younger adults.     

The fate of the retained ovaries following radical hysterectomy

To demonstrate the efficacy of flexible retrograde ureterorenoscopic holmium-YAG intracorporeal laser lithotripsy for the treatment of renal calculi, a total of 86 patients presenting to our hospital with renal calculi underwent flexible retrograde ureterorenoscopic holmium-YAG intracorporeal laser lithotripsy of their stones, and the data were collected prospectively. As extracorporeal shock wave lithotripsy is not available at our institution, all patients with renal calculi in this study were treated in a retrograde fashion using the Richard Wolf 6.0F semirigid ureteroscope, the 7.5F flexible ureterorenoscope, and the holmium-YAG laser by Coherent Inc. Except for inhospital consults or patients requiring admission secondary to infection, all cases were performed on an ambulatory basis. All renal calculi 3 cm or smaller were approached in a retrograde fashion. Where possible, the stones were initially debulked using the semirigid ureteroscope and the 550-microm fiber followed by the flexible ureterorenoscope in combination with the 360- or 200-microm laser fiber depending on stone position. Stones were fragmented until they were small enough to be removed by hydrocleansing. Using this technique, stone-free success rates for calculi 2.5 cm or smaller after a single treatment, regardless of stone composition or location, are superior to those of extracorporeal shock wave lithotripsy. For calculi between 2.5 and 3 cm, the results also are noted to be superior. We conclude that for calculi larger than 3 cm or for partial staghorn calculi, the treatment of choice appears to be a percutaneous approach.     

Reconstruction of the trachea

The effect of Imuran on experimental Masugi glomerulonephritis was checked in rabbits. The animals were grouped in biologically most similar pairs: one of the mates was treated with Imuran (4 or 8 mg/kg daily) the other served as control. Clinical and laboratory investigations were supplemented by histological and immunofluorescent studies of renal specimens taken on the 1st, 3rd, 7th, 10th, 21st, and 35th day of observation. The course of glomerulonephritis appeared much milder in Imuran-treated animals with a morphological counterpart in the form of reduced glomerular exudation and cellular proliferation. Only a slight and inconstant decrease of deposition of rabbit gamma-globulin and fibrin was observed in treatment animals in later stages of the experiment. Without denying a slight immunosuppressive effect, the authors admit that, in doses below 8 mg/kg daily, Imuran exerts a rather antiininflammatory effect on experimental glomerulonephritis.     

Schwannoma of the trachea

In this study we present a case of schwannoma of the trachea investigated with computer tomography (axial, precontrast) and magnetic resonance (1 Tesla, sagittal T1w before and after Gadolinium, sagittal T2w, coronal and axial after Gadolinium). The topographic abilities of MR allowed us to determine the exact location and extension of the tumor in the trachea. As far as we know, this study, based on magnetic resonance, is the first of the kind in the radiologic literature.     

The inferior thyroid veins--the ultimate guardians of the trachea

The inferior thyroid veins and their multiple tributaries are the ultimate guardians of the cervical trachea. Deeply embedded in the pretracheal fat pad, this plexus of veins is consistently encountered during low tracheostomy that accompanies conservation laryngral procedures as well as in tracheal reconstruction. In a high tracheotomy, the handling of the thyroid isthmus is simplified by an appreciation of these veins. Even cricothyrotomy is potentially complicated by hemorrhage sebsequent to a tear in a tributary of the inferior thyroid venous system. A cadaver study, employing 10 embalmed head and neck specimens, was performed to elucidate the tributary patterns of these veins. In every dissection there was at least one and as many as five veins overlying the trachea just below the thyroid isthmus. In 7 of 10 dissections a confluence of right and left inferior thyroid veins formed a large thyroid ima vein draining into the left innominate vein, and in 1 of 10 cases the thyroid ima vein drained into the right innominate. This confluence was present at a level which would be encountered in low tracheostomy or tracheal repair procedures. Six of 10 dissections presented large tributaries of the inferior thyroid veins overlying the cricothyroid membrane. An awareness of such anatomical considerations should result in safer surgical procedure performed in a dry operative field.     

机械通气患者气管插管的护理

随着危重症医学的不断发展及多功能呼吸机的广泛应用,使得气管插管行机械通气治疗成为内外科及重症领域重要的治疗环节.我院自2010年3月以来,应用机械通气治疗的病人达150例.现以经口气管插管为例将我们对机械通气管插管病人的护理体会如下.     

Localization of a G protein Gi2 in the cilia of rat ependyma, oviduct and trachea

In previous studies, the localization of a pertussis toxin-sensitive G protein was demonstrated in ependymal cilia, but the identification of the subtype of G protein was inconsistent. To clarify this issue, we studied the localization of Goalpha, Gi1alpha, Gi3alpha and Gi2alpha in the ciliated ependymal cells and in the cilia of some other tissues of rats using specific antibodies. The cilia of the ependymal cells that line the ventricular cavity of the brain were intensely immunoreactive for Gi2alpha, but not for Goalpha, Gi1alpha or Gi3alpha. Immunoblot analysis demonstrated higher levels of Gi2alpha in the ependymal cilia-rich pellet than in the motor area of the parietal cortex. At the ultrastructural level, the immunoreactivity specific for Gi2alpha was found predominantly in the cilia, but rarely in the microvilli or the basal bodies of ependymal cells. In cross-sections, the immunoreactivity specific for Gi2alpha was observed only in cell membranes, in particular, in the inner electron-dense leaflet of the trilaminar structure. In addition to that in the ependymal cilia, such specific localization of Gi2alpha was observed in the motile cilia in other tissues, including the oviduct and trachea. By contrast, the stereocilia in the ductus deferens were not immunopositive for Gi2alpha. These findings suggest that Gi2 might play an important role in the signal transduction in ciliary membrane-associated function(s) of the ependymal cells, oviduct and trachea.     

NO- and NO2-carrying molecules potentiate photorelaxation in rat trachea and aorta

Photorelaxation elicited by ultraviolet light (366 nm) was investigated on isolated rat thoracic aorta and trachealis. Rat tracheal smooth muscle but not aorta did not show UV-induced photorelaxation. Both streptozotocin, NO-carrying molecule and N omega-nitro-L-arginine, NO2-carrying molecule significantly enhanced photorelaxation, concentration-dependently, in rat trachealis and aorta. Methylene blue (10 microM) inhibited the potentiation action of streptozotocin and N omega-nitro-L-arginine in both tissues. Superoxide dismutase (300 U/ml) enhanced streptozotocin- and N omega-nitro-L-arginine-potentiated photorelaxation in rat trachealis, while pyrogallol (0.1 mM), a potent O2- generating agent, inhibited streptozotocin-potentiated photorelaxation in trachealis. Streptozotocin was much more effective than N omega-nitro-L-Arginine in potentiating of photorelaxation elicited by UV light in both tissues. From these findings, we conclude that streptozotocin and N omega-nitro-L-arginine produce EDRF like labile substance(s) by UV irradiation.     

Age and region-dependent contraction to alpha-adrenoceptor agonists in rat and guinea-pig isolated trachea

1. The influence of age and of region on alpha-adrenoceptor-mediated contraction to (-)-adrenaline and (-)-noradrenaline was examined in rat (4-136 weeks) and guinea-pig (2-156 weeks) isolated tracheal ring preparations with particular emphasis on the early (up to 12 weeks) maturation phase. 2. In rat tracheal rings, significant regional variation was observed with respect to maximal (-)-adrenaline-induced contraction, such that the greatest activity was seen in ring preparations from the laryngeal end of the trachea. Tracheal rings from the carinal end responded very poorly or were unresponsive to (-)-adrenaline, depending on animal age. These regional differences were seen across the age range. The potencies of (-)-adrenaline and (-)-noradrenaline remained unchanged with respect to animal age, but the maximum contractile tension that developed in response to these agonists increased with increasing animal age in all regions of the trachea. 3. In guinea-pig isolated tracheal tissue, maximum contractile responses (Emax) to (-)-adrenaline and (-)-noradrenaline remained unchanged with increasing animal age. In addition, there was no evidence for a region-dependence in the responsiveness of tracheal tissue to alpha-adrenoceptor-mediated contraction in this species. 4. In both guinea-pig and rat isolated tracheal tissue, alpha-adrenoceptor-mediated contraction appeared to involve the activation of alpha1-adrenoceptors.     

Interaction of the renin-angiotensin system, bradykinin and sympathetic nerves with cholinergic transmission in the rat isolated trachea

1. The present study was undertaken to investigate the interaction of the renin-angiotensin system (RAS), bradykinin and the sympathetic nervous system with cholinergic transmission in the rat airways. Experiments were performed on epithelium-intact and epithelium-denuded preparations of rat isolated trachea which had been incubated with [3H]-choline to incorporate [3H]-acetylcholine into the cholinergic transmitter stores. Tracheal preparations were subjected to electrical field stimulation (trains of 1 ms pulses, 5 Hz, 15 V) and the stimulation-induced (S-I) efflux taken as an index of transmitter acetylcholine release. 2. In both epithelium-intact and epithelium-denuded tracheal preparations, the alpha 2-adrenoceptor agonist UK14304 (0.1 and 1 microM) inhibited the S-I efflux, in a concentration-dependent manner. The inhibition of S-I efflux produced by UK14304 (1 microM) was antagonized by the selective alpha 2-adrenoceptor antagonist idazoxan (0.3 microM). Idazoxan (0.3 microM) alone had no effect on the S-I efflux. 3. Angiotensin II (0.1 and 1 microM) was without effect on the S-I efflux in either epithelium-intact or epithelium-denuded tracheal preparations. When angiotensin-converting enzyme was inhibited by perindoprilat (10 microM), angiotensin II (1 microM) was also without effect on the S-I efflux. Similarly, in the presence of idazoxan (0.3 microM), to block prejunctional alpha 2-adrenoceptors, angiotensin II (0.1 and 1 microM) did not alter the S-I efflux. When added alone, perindoprilat (10 microM) did not alter the S-I efflux. 4. In epithelium-denuded preparations, bradykinin (0.01-1 microM) inhibited the S-I efflux. In epithelium-intact preparations, there was also a tendency for bradykinin (0.1 and 1 microM) to inhibit the S-I efflux but this was not statistically significant. However, when angiotensin-converting enzyme and neutral endopeptidase were inhibited by perindoprilat (10 microM) and phosphoramidon (1 microM), respectively, bradykinin (1 microM) significantly inhibited the S-I efflux in epithelium-intact preparations as well as in epithelium-denuded preparations. The inhibition of the S-I efflux produced by bradykinin, in the combined presence of perindoprilat (10 microM) and phosphoramidon (1 microM), was unaffected by the additional presence of the cyclo-oxygenase inhibitor indomethacin (10 microM) and/or the nitric oxide synthase inhibitor NG-nitro-L-arginine (100 microM), in either epithelium-intact or epithelium-denuded preparations. 5. In conclusion, the findings of the present study suggest that airway parasympathetic nerves are endowed with alpha 2-adrenoceptors which subserve inhibition of transmitter acetylcholine release. Under the present conditions, however, transmitter acetylcholine release is not subject to transneuronal modulation by noradrenaline released from adjacent sympathetic nerves in the airways. Moreover, angiotensin II and perindoprilat do not appear to modulate acetylcholine release from parasympathetic nerves of the airways. In contrast, bradykinin inhibits acetylcholine release from airway parasympathetic nerves but this action of bradykinin is limited by the activity of epithelial angiotensin-converting enzyme and/or neutral endopeptidase. The inhibitory action of bradykinin on cholinergic transmission in the airways does not appear to involve the liberation of prostaglandins or nitric oxide.     

The retained intrapericardial sponge: value of the lateral chest radiograph

OBJECTIVE: Our objective was to identify reasons for the difficulty in diagnosing retained intrapericardial sponges and to determine ways to improve diagnostic accuracy. CONCLUSION: All three intrapericardially retained sponges were in the posterior pericardium, a region not visible to the surgeon. Radiographic detection of the sponges on standard anteroposterior projections is difficult because of exposure factors, other confusing linear markers, and metallic densities such as sternal sutures. However, knowledge of the typical location of a lost sponge and use of lateral radiographic projections may aid in early detection of this rare complication.     

The role of retained austenite in stress corrosion cracking of steels

The ability of retained austenite to affect stress corrosion cracking susceptibility has been examined in two steels, containing mechanically stable and unstable retained austenite of varying amounts and distributions. While limited improvements due to this constituent were observed in both threshold (where it may act as a compcting energy trap) and in growth rates (where it can act as a mechanical barrier and hydrogen sink), these were neither consistent nor more effective than other heterogeneities. Contrary to popular belief, retained austenite does not appear to be a consistently effective microstructural constituent, at least if the aim is to improve SCC performance at strength levels up to about 1000 MPa.     

The role of retained austenite in stress corrosion cracking of steels

The ability of retained austenite to affect stress corrosion cracking susceptibility has been examined in two steels, containing mechanically stable and unstable retained austenite of varying amounts and distributions. While limited improvements due to this constituent were observed in both threshold (where it may act as a compcting energy trap) and in growth rates (where it can act as a mechanical barrier and hydrogen sink), these were neither consistent nor more effective than other heterogeneities. Contrary to popular belief, retained austenite does not appear to be a consistently effective microstructural constituent, at least if the aim is to improve SCC performance at strength levels up to about 1000 MPa.