Sensory neuropeptides contribute to oedema formation in experimental burns

The role of primary sensory neuropeptides in experimental burns was investigated. It was shown that after scalding, substance P-like immunoreactivity is released into the lymphatic fluid of dogs. Substance P, injected intravenously, was shown to cause dose-dependent oedema formation in rat skin, as measured with the Evans blue-technique. Furthermore, capsaicin pretreatment, which depletes the neuropeptide content of primary sensory neurons, was shown to inhibit late oedema formation in rats.     

Effects of cooling and heating of the tooth on pulpal blood flow in man

Abstract Laser Doppler flowmetry (LDF) was used to study the changes in pulpal blood flow (PBF) evoked by application of cold or heat to the palatinal surfaces of teeth 11 or 21 in nine young subjects. Switching from a thermode temperature of 33° to 5° G on average induced a slow decrease of PBF to about 80% of control, and also warming to 39°C evoked a small reduction in most subjects. Inter individual differences were large, however, and both cooling and warming sometimes triggered a rise in PBF. In contrast, skin blood flow, as recorded with LDF in the forearm, invariably rose during warming and fell during local cooling. The results suggested a more complex interaction between local and nervously mediated effects of moderate changes in temperature in the tooth pulp than skin, and that the previous held view of cold and heat decreasing and increasing PBF, respectively, is wrong.     

Effects of posture and pneumoperitoneum during anaesthesia on the indices of left ventricular filling

Background. Laparoscopic surgery requires the use of pneumoperitoneum (PP). When combined with positional changes, pneumoperitoneum may cause marked circulatory alterations.
Methods. Eight anaesthetized cardiovascularly healthy patients, scheduled for laparoscopic cholecystectomy, were studied before and during pneumoperitoneum in three different postures (supine, Trendelenburg and reversed Trendelenburg), employing transesophageal echocardiography and pulmonary artery pressure monitoring.
Results. PP significantly increased end-diastolic area (EDA) and pulmonary capillary wedge pressure (PCWP) irrespective of posture. PCWP was significantly influenced by postural changes, whereas EDA was not. Further, changes in EDA and PCWP covaried during the investigation, but showed no linear correlation. Systolic function, measured as end-systolic area (ESA) and fractional area shortening (FAS), was not altered. Diastolic function, as assessed by the velocity rate of the trans-mitral flow during the early filling phase (E) and the atrial contraction (A), showed no change of the E/A ratio, whereas after the induction of PP there was a significant reduction of the E component.
Conclusions. In cardiovascularly healthy patients, the left ventricular volume is increased during pneumoperitoneum. Further, changes in invasive pressure determinations (PCWP) do not correlate linearly with changes in volume indices of left ventricular filling (EDA).     

Effect of dipyridamole (Persantin) on blood flow and patency of aortocoronary vein bypass grafts

The effect of dipyridamole was investigated in 360 patients undergoing coronary bypass surgery. They were randomly allocated to receive dipyridamole (100 mg orally q.i.d. for 2 days preoperatively, 5 mg/kg body weight/24 h i.v. peroperatively and 100 mg orally q.i.d. for 1 year postoperatively) or placebo. Withdrawn from the study were 48 patients on dipyridamole and 57 on placebo. Cardiovascular and/or cerebrovascular events or need for anticoagulant treatment were the reasons for withdrawal in 22 (13%) of the dipyridamole, and 34 (18%) of the placebo group. Logistic regression analysis of risk factors influencing graft patency showed significant relation to peroperatively measured coronary blood flow. A positive trend of treatment was observed (p = 0.08). Vein graft blood flow measured during bypass surgery (245 patients) was significantly greater in the dipyridamole group (p less than 0.01). The occlusion rate was lower in vessels with peroperative blood flow greater than 30 ml/min (vein-marginal p less than 0.01, vein-dexter p less than 0.05, vein-diagonal 0.05 less than p less than 0.1). Dipyridamole increases coronary blood flow and graft patency following coronary bypass surgery.     

Capsaicin induced release of multiple tachykinins (substance P, neurokinin A and eledoisin-like material) from guinea-pig spinal cord and ureter

The release of tachykinins from isolated slice preparations of the guinea-pig spinal cord and ureter was studied in vitro. Capsaicin (10 microM) caused release of substance P, neurokinin A and an eledoisin-like component from both the spinal cord and ureter. The release of tachykinins induced by capsaicin or potassium (60 mM) was calcium dependent. No detectable release of neurokinin B or neuropeptide K, an N-terminally extended form of neurokinin A, was induced by capsaicin. No detectable release of tachykinins could be demonstrated after exposure to agents which are known to activate C-fibre afferents, such as histamine, bradykinin, serotonin, prostaglandins E1, E2 or acetylcholine. Protein extravasation in the ureter, as determined by the Evans Blue extravasation technique was used as a functional correlate to the tachykinin release. Protein extravasation was induced in vivo by local intraluminal injections of capsaicin at several hundred-fold lower concentrations than those required to induce a detectable release of tachykinins in vitro. The difference may, however, partly depend on the experimental conditions and the detection limit of the tachykinin assay used. The protein extravasation response to capsaicin was absent after systemic capsaicin pretreatment, which causes a marked depletion of tachykinins in the ureter. In conclusion, capsaicin evokes release of several tachykinins from both central and peripheral endings of primary afferent neurons. The peptides released from sensory nerves in the periphery may induce effects such as protein extravasation and smooth muscle contraction.     

An ultrastructural study of 5-hydroxytryptamine-, thyrotropin-releasing hormone- and substance P-immunoreactive axonal boutons in the motor nucleus of spinal cord segments L7-S1 in the adult cat

The distribution and fine structure of 5-hydroxytryptamine-, thyrotropin-releasing hormone- and substance P-immunoreactive synaptic boutons and varicosities were studied in the motor nucleus of the spinal cord segments L7-S1 in the cat, using the peroxidase-antiperoxidase immunohistochemical technique and analysis of ultrathin serial sections. The 5-hydroxytryptamine-, thyrotropin-releasing hormone- and substance P-immunoreactive boutons had a similar ultrastructural appearance as judged from serial section analysis. The boutons could be classified into two types on the basis of their vesicular content, with one type containing a large number of small agranular vesicles together with only a few, if any large granular vesicles, while the other type contained a large number of large granular vesicles in addition to small agranular vesicles. The vesicles were spherical or spherical-to-pleomorphic. Postsynaptic dense bodies (Taxi bodies) were occasionally observed in relation to all three types of immunoreactive boutons, which almost invariably formed synaptic junctions with dendrites. Judged by the calibre of the postsynaptic dendrites, the boutons were preferentially distributed to the proximal dendritic domains of motoneurons. In one case, a substance P-immunoreactive bouton formed an axosomatic synaptic contact. In addition to synaptic boutons, 5-hydroxytryptamine-, thyrotropin-releasing hormone- and substance P-immunoreactive axonal varicosities containing a large number of large granular and small agranular vesicles but lacking any form of conventional synaptic contact were observed. Such varicosities were either directly apposing surrounding neuronal elements or separated from the neurons by thin glial processes. The origin of the immunoreactive boutons was not traced, but it was thought likely that the main source of the boutons was neurons with their cell bodies located in the medullary raphe nuclei.     

Effect of acquisition and analysis routines on gated blood pool measurements

Results obtained from gated equilibrium blood pool (GBP) studies are not only dependent on intrinsic variations, but also on the way in which images are acquired and analysed. The aim of this study was to investigate factors which could affect left ventricular time-activity curves. Temporal resolution was studied by comparing studies of 20 and 40 frames beat-1. Forty frames per beat resulted in a mean left ventricular ejection fraction of 0.48 compared to 0.46 for 20 frames beat-1. The mean difference of 0.02 was significant (P less than 0.01) as was the mean difference in maximum emptying rate (MER = 0.28, P less than 0.01) and in maximum filling rate (MFR = 0.38, P less than 0.01). No significant differences in ejection fraction (EF) values were found between acquisitions made in list and frame mode, but the mean differences for MER = 0.03 (P less than 0.05) and MFR = 0.01 (P less than 0.02) were significant. For patient repositioning and intra-observer variations no significant differences were found. In patients with normal EF values (greater than 0.5) no significant differences were found in the inter-observer study. In patients with anterior myocardial infarction (AMI), significant differences were found in EF, MER and MFR (EF = 0.02, P less than 0.001; MER = 0.2, P less than 0.01; MFR = 0.24, P less than 0.01). Significant differences were found in all values when comparing a semi-automatic method of evaluation with two automatic methods. In conclusion the results from this study suggest that acceptable reproducibility can be achieved in GBP studies, provided the method of analysis is not changed between studies.     

Cloning of human hybridoma, myeloma and lymphoma cell lines using enriched human monocytes as feeder layer

Human monocytes were prepared from peripheral blood by buoyant density centrifugation and subsequent absorption-elution on a column of gelatin beads. The eluted fraction containing 60-80% monocytes was used as feeder layer in cloning of the human lymphoma line RH-L4, the human myeloma line SKO-007, and a human hybridoma cell derived from the latter line. Cloning efficiencies were high in both liquid and semisolid media with all 3 cell lines tested. Feeder monocytes could also be successfully used after having been stored in liquid nitrogen.