The effect of morphine and naloxone on the interaction of afferent signals of differing modalities in the spinal cord

The effect of the electrical nerve stimulation with low (2-4 V, 100 Hz, 5 min) and high (45 V, 1 Hz, 1 min) intensity on the nociceptive responses in the ventrolateral tracts was studied in unanesthetized rats with the transsected spinal cord. Both kinds of stimulation reduced nociceptive responses but the effect of low-intensity stimulations was diminished when they were repeated and was absent over 24 hours after spinalization. The effect of low-intensity stimulation was abolished by naloxone (0.1 and 1 mg/kg) and was reduced during the antinociceptive effect of morphine (1 and 4 mg/kg). The effect of high-intensity stimulation was preserved over 24 hours after spinalization and after repeated stimulations. It was not changed by naloxone and morphine.     

SEAT-BELT SYNDROME REVISITED

This report describes a complex syndrome of injuries occurring in a young female who was a back seat passenger wearing a lap-belt restraint in a high-speed road traffic accident. As a consequence of the forced flexion distraction injury of her lumbar spine, she sustained a fracture-subluxation of the first lumbar vertebra in association with a jejunal perforation and extensive small intestinal mesenteric laceration. She also had a large traumatic hernia of the anterior abdominal wall, which was overlooked at primary laparotomy. This report highlights collectively the classical combination of injuries associated with the lap-belt syndrome and demonstrates the importance of carefully inspecting the anterior abdominal wall for deficiencies, because traumatic herniation may be easily overlooked.     

A neurochemical analysis of the interaction of afferent signals at the spinal cord level]

The antinociceptive effect of electrical nerve stimulation with low (2-4 V, 100 Hz, 5 min) and high (45 V, 1 Hz, 1 min) intensity in the unanesthetized rats with the transsected spinal cord was determined by microelectrode recording in the ventrolateral tracts. The action of low intensity stimulation was reduced by yohimbine or during antinociceptive effect of clonidine. It was potentiated by baclofen and physostigmine. Prazosin, bicuculline, methysergid, strychnin, atropine, muscimole, THIP did not influence the effect of low-intensity stimulation. Metysergide partially reduced the effect of high-intensity stimulation. The data suggest that 2-adrenoreceptors are involved in the action of low-intensity stimulation and 5-HT-receptors are involved in the action of high-intensity one. For potentiating the effect of low-intensity stimulation on the segmental level it is possible to use baclofen and physostigmine.     

Phase II evaluation of dibromodulcitol and actinomycin D,hydroxyurea, and cyclophosphamide in previously untreated patients with malignant melanoma

In this Eastern Cooperative Oncology Group (ECOG) phase II study, dibromodulcitol (DBD) and a combination of actinomycin D, hydroxyurea, and cyclophosphamide (AHC) were compared with methyl-CCNU, the current ECOG standard, in patients who had received no prior chemotherapy for disseminated malignant melanoma. The response rates were 6% (3/50) for AHC, 9% (3/34) for DBD, and 14% (7/49) for methyl-CCNU. Median survival times were 4, 5, and 6 months, respectively. Neither regimen appears to offer any advantage over methyl-CCNU as front-line therapy for patients with disseminated melanoma.     

DNA binding chelates for nonviral gene delivery imaging

Noninvasive in vivo monitoring of gene delivery would provide a critically important information regarding the spatial distribution, local concentration, kinetics of removal and/or biodegradation of the expression vector. We developed a novel approach to noninvasive gene delivery imaging using heterobifunctional peptide-based chelates (PBC) bearing double-stranded DNA-binding groups and a technetium-binding amino acid motif. One of such chelates: Gly-Cys(Acm)-Gly-Cys(Acm)-Gly-Lys(4)-Lys-(N-epsilon-[4-(psoralen-8-yloxy)]butyrate)-NH(2) has been characterized and labeled with reduced (99m)Tc pertechnetate (oxotechnetate). The psoralen moiety (a DNA binding group of PBC) allowed linking to double-stranded DNA upon short-term irradiation with the near UV range light (>320 nm). Approximately 30-40% of added (99m)Tc-labeled PBC was nonextractable and co-eluted with a model pCMV-GFP vector during the gel-permeation chromatography. Nuclear imaging of "naked" DNA and DNA complexes with lipid-based transfection reagents ("lipoplexes") has been performed after systemic or local administration of (99m)Tc-PBC-labeled DNA in mice. Imaging results were corroborated with the biodistribution using (99m)Tc-PBC and (32)P-labeled DNA and lipoplexes. A markedly different biodistribution of (99m)Tc PBC-labeled DNA and lipoplexes was observed with the latter being rapidly trapped in the liver, spleen and lung. (99m)Tc PBC-DNA was used as an imaging tracer during in vivo transfection of B16 melanoma by local injection of "naked" (99m)Tc PBC-DNA and corresponding lipoplexes. As demonstrated by nuclear imaging, (99m)Tc PBC-DNA lipoplexes showed a slower elimination from the site of injection than (99m)Tc PBC-DNA alone. This result correlated with a higher expression of marker mRNA and green fluorescent protein as determined using RT-PCR and immunohistochemistry, respectively.     

PCR with arbitrary primers: approach with care

New techniques have recently been described that employ the polymerase chain reaction (PCR) to amplify arbitrary regions of a genome using a single primer. The techniques reveal polymorphisms in insect taxa that lack allozyme variation and, for the first time, permit genetic polymorphisms to be rapidly analysed in small arthropods (e.g. mites, endoparasitic wasps). The methods have been used in identification of sub-species and cryptic species, and have applications in population genetics and genetic fingerprinting. They are fairly inexpensive, do not require the use of radioactivity, are relatively simple to learn and can easily be adapted to most laboratories. However, their application is not without technical problems and practical limitations. The purpose of this note is to indicate the critical factors to consider before launching into their use. We chiefly emphasize that most polymorphisms revealed by these methods segregate as dominant markers. Furthermore, application of these techniques requires extensive standardization and may not prove to be reproducible among various laboratories especially those employing different types of thermal cyclers. There are some unique features of these polymorphisms to consider when using them in genetic fingerprinting. In addition, because the techniques amplify arbitrary regions of genomes, similarly sized fragments amplified between two species may not be homologous. This argument and empirical observations suggest that PCR with arbitrary primers will have limited application in molecular systematics above the intraspecific level.