Functional assessment of sciatic nerve reconstruction: biodegradable poly (DLLA-epsilon-CL) nerve guides versus autologous nerve grafts

The aim of this study was to compare functional nerve recovery after reconstruction with a biodegradable p(DLLA-epsilon-CL) nerve guide filled with modified denatured muscle tissue (MDMT), or an autologous nerve graft. We evaluated nerve recovery using walking track analysis (measurement of the sciatic function index [SFI]) and electrostimulation tests. Functional nerve recovery after reconstruction with a biodegradable p(DLLA-epsilon-CL) nerve guide filled with MDMT was faster when compared with nerve reconstruction using an autologous nerve graft. We conclude that in case of a short nerve gap in the rat, reconstruction can best be carried out using a p(DLLA-epsilon-CL) biodegradable nerve guide filled with MDMT.     

Pharmacology of antimigraine drugs

The drugs used in migraine therapy can be divided into two groups: agents that abort an established migraine attack and agents used prophylactically to reduce the number of migraine attacks. Both groups have drugs that are specific for migrainous headaches and that are non-specific, and are used to treat the accompanying headache (analgesics), vomiting (anti-emetics), anxiety (sedatives and anxiolytics), or depression (antidepressants). The main drugs with specific action on migraine include ergot alkaloids (ergotamine, dihydroergotamine), agonists (sumatriptan) or partial agonists (methysergide) at a specific subtype of 5-HT₁-like receptors, -adrenoceptor antagonists (propranolol, metoprolol), calcium antagonists (flunarizine) and anti-inflammatory agents (indomethacin). The pharmacological basis of therapeutic action of several of these drugs is not well understood. In the case of the ergot alkaloids and 5-HT₁-like receptor agonists, however, it is likely that the antimigraine effect is related to the potent and rather selective constriction of the large arteries and arteriovenous anastomoses in the scalp and dural regions. In addition, these drugs inhibit plasma extravasation into the dura in response to trigeminal ganglion stimulation, but it is possible that this effect is related to the selective vasoconstriction in the extracerebral vascular bed. The selectivity of the pharmacological effects of these antimigraine drugs (constriction of the extracerebral arteries and arteriovenous anastomoses, poor penetration into the central nervous system and the absence of an antinociceptive effect even after intrathecal administration) strongly suggests that excessive dilatation in the extracerebral cranial vasculature, probably initiated by a neuronal event, is an integral part of the pathophysiology of migraine.     

Technetium-99m-MRP20, a potential brain perfusion agent: in vivo biodistribution and SPECT studies in non-primate animals

MRP20 (N-(2(1H pyrolylmethyl]N'-(4-pentene-3-one-2] ethane-1,2-diamine) complexes with technetium-99m, yielding a neutral, lipophilic species. This compound has been characterized as [TcO(MRP20)]. Biologic investigation of [99mTc][TcO(MRP20)] in female rats showed 2.35% ID in the brain 30 min p.i. with no significant wash-out over 3 hr. A single-photon emission computed tomography (SPECT) study in a dog demonstrated rapid tracer uptake in the brain, reaching a maximum within 1 min, with 2.24% i.d. 15 min p.i., decreasing to 1.7% after 4 hr. The complex undergoes hydrolysis in vitro forming a cationic species. This is possibly the trapping mechanism in the brain in vivo. The main excretory route of [99mTc][TcO(MRP20)] is via the hepatobiliary tract. There is evidence of some "in vivo" cell labeling and soft-tissue uptake.     

Antispasmodic Activity of Origanum compactum

In addition to the spasmolytic activity of ORIGANUM COMPACTUM, the antagonistic effect of the main components thymol and carvacrol is investigated on the isolated guinea-pig ileum, induced by carbachol, histamine, 1,1-dimethyl-4-phenylpiperazinium iodide and BaCl (2). The l-noradrenaline contractions on the rat vas deferens are also reduced by both of phenols and the Origanum macerate. pD' (2) values and relative potency to papaverine illustrate the affinity of the isomers. It is concluded that thymol and carvacrol act as non-competitive antagonists and are not significantly different from each other.     

Oploskarakteristieken van enkele cholinetheofyllinaattabletten

Dissolution profiles of choline theophyllinate tablets as obtained from twelve manufacturers (or distributors) and two choline theophyllinate containing trade mark products (Cholegyl^® and Dilasmyl^®) have been studied, using the apparatus for the disintegration test as described inPh. Eur. ed 1. Tablets have been tested both according to the monograph of plain coated tablets and that of enteric coated tablets. Cholegyl^® proved to meet the specifications of enteric coated tablets, but several of the generic products did not and (although chemically equivalent) consequently cannot be considered as being biopharmaceutic equivalents to the trade mark product.Large differences were found between the dissolution characteristics of the various generic products. Prescribing is dissuaded.Samenvatting Oplosprofielen van cholinetheofyllinaattabletten (farmaceutische preparaten) zoals deze werden verkregen van twaalf fabrikanten (of leveranciers) en van twee cholinetheofyllinaat bevattende spécialités (Cholegyl^® en Dilasmyl^®) werden bestudeerd met behulp van het apparaat voor de desintegratietest (Ph. Eur. ed. i). De tabletten werden getest volgens de monografie voor omhulde tabletten en die voor maagsapresistente tabletten. Cholegyl^® bleek te voldoen aan de eisen gesteld aan maagsapresistente tabletten, maar verscheidene van de farmaceutische preparaten (loco's) voldeden niet aan de gestelde eisen. Deze farmaceutische preparaten (hoewel chemisch equivalent) kunnen derhalve niet worden beschouwd als farmaceutische equivalenten van het genoemde spécialité.Er werden grote verschillen gevonden tussen de oplosprofielen van de diverse farmaceutische preparaten. Het voorschrijven van deze preparaten wordt afgeraden.     

Changes in cell surface molecules associated with in vitro culture of prostatic stromal cells

BACKGROUND: Prostate stromal cells can be readily cultured in vitro. Are these proliferating cells representative of stromal cells in situ? Since the expression of cell surface molecules, like the cluster of differentiation (CD) antigens, can be affected by changes in physiological conditions cultured stromal cells may differ from uncultured stromal cells in their complement of CD molecules. METHODS: Prostate stromal cells were prepared from tissue specimens and cultured. Flow cytometry was used to analyze the expression of 107 CD molecules in the resultant cells. Expression of the CD molecules by prostate cells in situ was done by immunohistochemistry. RESULTS: The expression of a number of cell surface molecules such as CD10, CD13, CD26, and CD44 is elevated in prostatic stromal cells cultured in vitro. These are markers of epithelial cells in tissue. Other molecules expressed by the cultured stromal cells include CD29, CD49a, CD49b, CD49d, CD49f, CD51/61, CD54, CD55, CD56, CD58, CD59, CD61, CD71, CD79b, CD81, CD82, CD90, CD95, CD107a, CD130, and CD147. Among these are stromal, epithelial, and nonstromal/nonepithelial markers as defined by tissue immunohistochemistry. CONCLUSION: Cultured stromal cells express a number of CD molecules normally found in other cell types of the prostate. Cells can express different CD molecules under different conditions.     

Eureka-project: ‘totally implantable artificial larynx’: progress report

Objective. The European Eureka project ‘Artificial larynx’ aims at realizing an implantable artificial larynx, consisting of artificial vocal folds, artificial epiglottis, tissue connector for tracheal fixation and valve mechanism to switch between breathing and speaking. The last part has been realized. Because its functioning is identical to a tracheostomal valve, it was tested as such. Materials and methods. The device consists of two valves: a speech valve, that will be open during normal breathing and closed by strong expiration and a cough valve that opens during coughing and closes automatically during inhalation. Magnets keep the valves in the breathing position. The magnetic force can be varied. Several prototypes have been tested in vitro and in situ. Results. The prototypes showed good in vitro behaviour. The range of adjustability of speech and cough was wide enough, flow resistance acceptable. This was confirmed by preliminary in vivo experiments. Patients were enthusiastic; hands-free speaking and coughing is possible. Conclusion. Numerous problems have to be solved to produce an artificial larynx. Each solution generated up till now, however, can already be applied to improve the existing rehabilitation process of laryngectomized patients.     

Mouse cytomegalovirus in developing brain tissue: analysis of 11 species with GFP-expressing recombinant virus

Cytomegaloviruses (CMVs) are species-specific large double-stranded DNA viruses. Mouse and human CMVs have a similar morphology, similar gene sequence, and exert similar cellular effects, but the replication of the virus outside its primary host species is limited. This may confer upon CMV certain advantages for expression of foreign genes or cellular labels in brain cells of nonhost species. We examined the ability of recombinant mouse (m)CMV expressing green fluorescent protein (GFP) to serve as a vector for transgene expression in developing neurons and glia outside the normal host species. For comparative purposes, 11 species were examined. Mouse CMV reporter gene expression was particularly strong in the developing brain of its normal host species, mouse, where it replicated in cultures and brain slices, leading to cell death. All mammalian species tested (human, rat, gerbil, hamster, mouse) showed reporter gene expression after mCMV infection. High levels of mCMV infection were also found in chicken central nervous system cells in vitro, and a low level of mCMV expression was found after an initial delay in turtle neurons and glia. No mCMV reporter gene expression was found in frog cells or aplysia neurons or glia or in drosophila or fungal cells. Infection of nonmouse neurons by low concentrations of mCMV led to strong expression of GFP in dendrites and axons with normal morphology. Despite the lack of replication, high doses of mCMV induced morphologic changes in neurons and glia from hamster and rat brain slices, leading to cells rounding up, and to the formation of giant cells consisting of an aggregate of many cells fused together into a syncytium. In contrast, in human hippocampal slices, GFP-expressing cells infected with mCMV had a relatively normal appearance 12 days after inoculation. To determine whether a CMV from another species could serve as a vector for gene transfer, a recombinant human CMV-expressing GFP was used for transgene expression in rat brain cells in vitro. Cytomegaloviruses thus have potential as useful vectors for gene transfer and labeling central nervous system cells, with the actions of CMV being dependent on a number of factors.