Neuromuscular transmission in a mammalian preparation during exposure to enflurane.

The effects of enflurane on motor nerve terminals and muscle endplates were studied in the rat phrenic nerve-diaphragm preparation using standard microelectrode recording techniques. Muscle endplate interaction with enflurane was suggested by depression of the amplitude of miniature endplate potentials (MEPP's) without change in frequency, increased duration of MEPP's and endplate potentials (EPP's) increased threshold for generation of muscle action potentials, and inhibition of the endplate depolarization induced by succinylcholine. Evidence of nerve terminal effects of enflurane was limited to a greater relative decline of EPP amplitude during tetanus, indicative of failure to maintain transmitter output at rapid rates of stimulation. It is concluded that the depressant effect of enflurane on indirectly elicited muscle twitch is primarily due to an impairment of the action of muscle endplate on adjacent membrane; however, the relative importance of prejunctional depression, seen only during rapid nerve stimulation, cannot be assessed from the present data.     

Micro-iontophoretic studies on neurones in the cuneate nucleus

1. Cuneate cells in anaesthetized cats were strongly excited by L-glutamate, and somewhat less by D-glutamate; cells which receive afferents from hair receptors were particularly sensitive.2. Glutamate could be used to demonstrate post-synaptic inhibitory inputs from the dorsal column, the medial lemniscus and the frontal cortex.3. Many cuneate cells were also strongly excited by adenosinetriphosphate (ATP); this was probably due to the chelating action of ATP, as citric acid was also quite effective.4. gamma-Aminobutyric acid (GABA) readily blocked all forms of spontaneous and evoked activity, except antidromic invasion of cuneothalamic neurones; cells which receive proprioceptive afferents were particularly sensitive to GABA. Glycine had a comparable effect.5. Acetylcholine (ACh), catecholamines, histamine, 5-hydroxytryptamine (5-HT) and an extract containing substance P mostly had only weak depressant actions. Cholinergic and mono-aminergic mechanisms are probably not very significant in the cuneate.6. These results are consistent with the possibility that glutamate and GABA (or glycine), or some closely related compounds, are the main excitatory and inhibitory transmitters in the cuneate nucleus.7. If ATP is released from afferent nerve endings, it could also play a significant role in excitation.     

Administration of a complex chemotherapy regimen: inpatient versus outpatient treatment

The ability to administer a complex chemotherapy regimen, adriamycin and cis-platinum, was evaluated in two different settings, inpatient and outpatient. On comparison, outpatient administration proved superior. This resulted from the interest and experience of the staff administering the medications. It is recommended that outpatient administration of chemotherapy, even with complex protocols, be employed whenever feasible.     

Effects of pesticides on DNA and protein of shrimp larvae Litopenaeus stylirostris of the California Gulf

Recently, diverse pathologies and massive mortalities have been presented in shrimp hatcheries located along the California Gulf; therefore, toxic responses of shrimp larvae were used as biomarkers of pesticide pollution, because in this region intensive agriculture is practiced. Shrimp larvae were exposed to DDT, azinphosmethyl, permethrine, parathion, chlorpyrifos, malathion, endosulfan, and carbaryl, in order to determine LC50, DNA adducts and/or breaks, and total protein in larvae. The results indicate reductions in protein and DNA in larvae exposed to these pesticides, and in those exposed to DDT, breaks and/or adducts were registered. It is possible that pesticide pollution is a cause of these problems, because reduction in protein indicates a decrease in larvae growth rate and DNA breaks or adducts have been related to pathologies and carcinogenesis in many aquatic organisms.     

Esthesioneuroblastoma: report of 2 case

The esthesioneuroblastoma is a very uncommon malignant growth arising from olfactory epithelium. Almost 400 cases have been published since its was first described. Owing to the meager figures of these series is not possible to drawn out conclusions in order to establish an unique protocol of treatment for this tumoral type. We present 2 cases diagnosed in our Department, each diversely treated and comment the results.     

Non-invasive fungal sinusitis: allergic fungal sinusitis and sinusal mycetomas

We review non-invasive fungal sinusitis (FS) cases treated at our Unit following the recent SF classification, based on physiopathology, treatment and prognosis. We report 7 FS cases treated during 2 years and followed a minimum of 24 months. They are two allergic FS, one of them related to an allergic bronchopulmonary aspergillosis, and five mycetomas, two of them without a sinusal foreign body, sphenoidal and maxillary respectively, and three caused by a maxillary foreign body. All were treated by endoscopic sinus surgery (ESS). The two allergic cases were also treated with systemic corticoids in the postoperative period. We review the clinical presentation of the different types of non-invasive FS, the importance of endoscopy and imaging techniques in their management, the usefulness of ESS, the common association of FS to foreign bodies, and their prognosis.