Amelioration of experimental allergic neuritis by sodium fusidate (fusidin): suppression of IFN-gamma and TNF-alpha and enhancement of IL-10.

The immunomodulating antibiotic drug fusidic acid and its sodium salt sodium fusidate (fusidin) ameliorate several organ-specific immunoinflammatory diseases. Because preliminary observations suggest that fusidin may also exert a beneficial effect in Guillain-Barré syndrome (GBS), here we have studied the effects of fusidin on actively induced experimental autoimmune neuritis (EAN) in rats, a known animal model for GBS. Both prophylactic and therapeutic treatment with fusidin (4 mg/rat day ip) markedly ameliorated the clinical course of the disease compared to vehicle-treated animals. The beneficial effects were associated with profound modifications of the capacity of these rats to produce and release pro- and anti-inflammatory cytokines such as IFN-gamma, TNF-alpha and IL-10, which are important in regulating the development of EAN.     

Irrigating fluid absorption during transcervical endometrial resection

Abstract: Transcervical resection of the endometrium (TCRE) is a new alternative to hysterectomy in women with menorrhagia. The present thesis describes the incidence, extent and monitoring of absorption of the distention medium in patients undergoing this operation. The thesis also focuses on the prerequisites for absorption by different pathways and on the dangers inherent in the use of different irrigating solutions. The fluid balance, the serum sodium level and the ethanol concentration in the expired breath were measured every 10 min throughout 62 TCREs using glycine 1.5%-ethanol 1% for irrigation. Absorption occurred in 61 of these patients. Uptake by the extravascular route was almost as common as intravenous absorption. The ethanol concentration in the breath correlated strongly with the fluid absorption, as indicated by the other methods. The usefulness of the breath ethanol measurement to indicate the venous blood-ethanol concentration was challenged in 10 women. They were given an intravenous infusion of 0.4 g/kg of ethanol over 20 min while they were anaesthetized with isoflurane, as well as when they were awake. The results show that the breath-ethanol value reflected well the concentration measured in venous blood. However, general anaesthesia promoted higher overall ethanol values. This could be attributed to a decrease in the central distribution volume for ethanol during isoflurane anaesthesia, which can probably be explained by vasodilatation. The absorption of irrigating fluid was also studied in 25 women when uterine surgery was not performed. The uterus was filled with methylene blue-stained glycine-ethanol fluid and the pressure was gradually increased. Absorption of small amounts of fluid through the endometrium was detected when the intrauterine pressure exceeded 160 mmHg (n=10), while fluid leakage through the fallopian tubes occurred through the laparoscope at varying pressures, sometimes as low as 40 mmHg, in 14/15 women. The chance of survival after intravenous overhydration with the three most frequently used irrigating solutions was studied in 120 mice. Increasing volumes of glycine 1.5%, mannitol 5% and sorbitol 2%-mannitol 1% were given. The results demonstrate that mannitol 5% is associated with a better chance of survival within 24 h than the other solutions. The flow of solutes across the peritoneal membrane was studied in 10 women by infusing 1.5 1 of glycine-ethanol into their abdominal cavity over 20 min. The half-time for the equilibration of ethanol was the fastest (mean 33 min) while that for sodium required a 3-fold longer and glycine a 4-fold longer time. This illustrates that ethanol indicates accumulation of irrigating fluid in the peritoneal cavity before hyponatremia and hyperglycaemia develop in the patient. In conclusion, the present thesis shows that fluid absorption is common during TCRE and that it can be monitored by measuring ethanol in the expired breath, both in awake patients and during isoflurane anaesthesia. Mannitol solution should probably be used for irrigation to minimize the risk of death if a large-sized absorption occurs.     

Theoretical and experimental evaluation of phase-dispersion effects caused by brain motion in diffusion and perfusion MR imaging

We investigated intravoxel phase dispersion caused by pulsatile brain motion in diffusion spin-echo pulse sequences. Mathematical models were used to describe the spatial and temporal velocity distributions of human brain motion. The spatial distribution of brain-tissue velocity introduces a phase spread over one voxel, leading to signal loss. This signal loss was estimated theoretically, and effects on observed diffusion coefficient and perfused capillary fraction were assessed. When parameters from a diffusion pulse sequence without motion compensation were used, and ECG triggering with inappropriate delay times was assumed, the maximal signal loss caused by brain-motion-induced phase dispersion was predicted to be 21%. This corresponds to a 95% overestimation of the diffusion coefficient, and the perfusion-fraction error was small. Corresponding calculations for motion-compensated pulse sequences predicted a 1% to 1.5% signal loss due to undesired phase dispersion, whereas experimental results indicated a signal loss related to brain motion of 4%.     

Distribution of acidic fibroblast growth factor-like immunoreactivity in rat skeletal muscle fibers

Acidic fibroblast growth factor (aFGF) is a mitogenic, angiogenic and neurotrophic growth factor which promotes proliferation, but delays differentation of cultured myoblasts. Its mRNA is expressed in the skeletal muscle, however the distribution of aFGF in the postnatal skeletal muscle is poorly characterized. In the present study, the distribution of aFGF-like immunoreactivity (LI) was examined in developing and adult rat skeletal muscle fibers. In addition, the effect of the transection of the sciatic nerve on aFGF-LI in calf muscle fibers was examined. From the first postnatal day on, aFGF-immunoreactive (IR) muscle fibers were observed in different calf muscles. From the 7th postnatal day on a large number of muscle fibers exhibited aFGF-LI in the soleus muscle, some in plantaris and only few in gastrocnemius and extraocular muscles. Double-labelling with fast-myosin antibody showed that aFGF-LI was restricted to the slow oxidative muscle fibers. aFGF-IR intrafusal muscle fibers were seen in developing and mature muscle spindles. In addition, aFGF-IR nerve fibers and myoneural junctions were observed in different muscles. Transection of the sciatic nerve did not noticeably alter the expression pattern of aFGF-L[ in calf muscles during two-week period.The present study demonstrates aFGF-LI in the rat slow oxidative muscle fibers where it may have fiber-type specific functions in addition to its known trophic effects.     

Multiple Members of the Leucokinin Neuropeptide Family are Present in Cerebral and Abdominal Neurohemal Organs in the Cockroach Leucophaea maderae

Two neurohemal organs of the cockroach Leucophaea maderae , the corpora cardiaca and the lateral heart nerve are known to contain leucokinin immunoreactive material. We examined the corpora cardiaca and the lateral heart nerve to establish whether these neurohemal organs store all 8 known leucokinin isoforms or if the leucokinins have a differential distribution. Extracts of corpora cardiaca and abdominal hearts with attached lateral heart nerve were separated on reversed phase high performance liquid chromatography (rpHPLC), then tested for leucokinin immunoreactivity by a radioimmunoassay (RIA) able to detect all 8 leucokinin isoforms. Extracts from brain and optic lobes were also separated and assayed in the RIA. Synthetic leucokinin 1–8 were subjected to rpHPLC and their different retention times established by RIA for reference. Leucokinin immunoreactive material originating from the corpora cardiaca and lateral heart nerves eluted in fractions corresponding to those of the synthetic leucokinin 1–8. In this study we have thus demonstrated that probably all 8 leucokinin isoforms are stored in the corpora cardiaca and the lateral heart nerve. These observations suggest that all 8 leucokinins are likely to be released as neurohormones into the circulation.     

Functional state of the mandible and rolling-gliding characteristics in the TMJ.

For the physiological intact stomatognathic system, the three main functional states (occlusat articular functions, free mandibular movements, and ideal bolus function) were biomechanically discussed concerning the structure of movement, rolling-gliding characteristics, and force transfer in the temporomandibular joint (TMJ). In all three cases, rolling is not possible in the TMJ since the instantaneous rotational axis is positioned outside of the joint-rolling is not necessary because the TMJ is not loaded by appreciable forces. In the aged stomatognathic system with a lost discus and considerable Loads in the TMJ, however, the attrition of the joint is eased by rolling movement at the articulating surfaces. The destruction of the discus can be seen as a physiological adaptation which brings back the joint to an original odontogen condition.     

Morphological structures and protrusive cranial border guidance of the temporomandibular joint of Cercopithecus mona.

Morphological parameters of the temporomandibular joint (TMJ) of Cercopithecus mona were analyzed by sagittal medial/lateral slicing of the entire joint. The slice contours of the osseous structures of the joint surfaces were approximated by circles. In this manner, the main parameter of the protrusive cranial border guidance, the protrusive dimeric Link chain (DLC), could be measured. In each joint, all slices yielded protrusive DLCs which were nearly parallel to each other. In medial/lateral direction all parts of the joints participate in force transmission in initial protrusive cranial border function.