Identification of a secretomotor centre in the brain of Locusta migratoria, controlling the secretory activity of the adipokinetic hormone producing cells of the corpus cardiacum

After retrograde filling of axons terminating in the glandular lobe of the corpus cardiacum (CC) of Locusta migratoria with cobalt chloride, a paired group of about 15 cobalt containing cells was demonstrated in the lateral area of the protocerebrum. The axons of these cells run via the NCC II into the glandular lobe of the CC. These small neurons have the characteristics of secretory cells; they contain secretory granules of about 1000 A in diameter. The axon terminals in the glandular lobe, making synaptic contacts with the glandular cells, contain secretory granules of the same size. It is therefore concluded that the cell groups in the protocerebrum control the activity of the glandular cells which produce an adipokinetic hormone. Arborizations of fibers of the lateral secretomotor cells are present in the dorsal neuropile of the protocerebrum, ventral of the mushroom bodies and along the tracts of the NCC I within the brain. It is proposed that these arborizations are sites of synaptic input. It is discussed that the axons of these cells might receive additional synaptic input in the storage lobe of the CC. The localization of cell bodies, the axons of which enter the storage part of the CC is described. The course of the axon tracts of the various cell groups in the protocerebrum and their connections with the NCC I and NCC II are demonstrated.     

Prevalence and correlates of lower extremity arterial disease in elderly women

1. The neuroantibody approach, based on the expression of selected monoclonal antibodies by cells of the nervous system, has recently been described (Cattaneo and Neuberger, 1987; Piccioli et al., 1991). In order to apply this experimental strategy to study the role of nerve growth factor (NGF) in the central nervous system (CNS), we exploited the monoclonal antibody (mAb), alpha D11, which neutralizes very efficiently the biological activity of NGF, both in vitro and in vivo (Cattaneo et al., 1988). 2. The alpha D11 antibody chains were cloned and expressed in COS cells as rat/human chimaeric proteins. The cloned antibody was shown to display all the properties of the parental alpha D11 antibody, including its ability to neutralize NGF biological activity. 3. This will allow us to engineer the expression of recombinant alpha D11 antibodies in the CNS, to study the role of NGF in the developing and adult nervous system. This approach can be extended to other neurotrophic factors for which neutralizing monoclonal antibodies are available.     

Epidemiology of bluetongue in Central America and the Caribbean: initial entomological findings. Regional Bluetongue Team

Forty-four species of Culicoides (Diptera: Ceratopogonidae) were caught in insect light traps during the first 2 years of studies on the epidemiology of bluetongue virus in the Caribbean and Central America. Traps were operated near sentinel ruminants which were bled monthly for serologic evaluation and then virus isolation. More than 570,000 individuals were identified. Culicoides insignis Lutz accounted for 90% of the catch, C. filarifer Hoffman/C. ocumarensis Ortiz 5%, C. furens Poey 3% and C. pusillus Lutz 2%. Other species accounted for less than 1% of the total catch. Sentinel ruminants became seropositive when C. insignis populations were high at many study sites. At a few sites C. pusillus and C. filarifer/C. ocumarensis were predominant or were present in large numbers during seroconversions of sentinels. Virus isolations were obtained from sentinel ruminants during times when these same species were present in large populations.     

Benzodiazepine withdrawal reaction in two children following discontinuation of sedation with midazolam

OBJECTIVE: To report the occurrence of recurrent benzodiazepine withdrawal reactions in two very young children following discontinuation of sedation with midazolam. CASE SUMMARY: A 15-month-old boy with apneic episodes was sedated with midazolam for 12 days with constant infusion. Half a day after discontinuation of the midazolam the boy became restless, tachycardic, and hyperpyrexic. When midazolam was readministered, all symptoms disappeared. Four days later midazolam was again discontinued and within 12 hours the same signs and symptoms reappeared. Midazolam infusion was restarted, and the signs and symptoms disappeared for the second time. After thoracotomy, a 14-day-old boy received intravenous midazolam for sedation for 29 days. Within 12 hours after discontinuation of midazolam he became restless, developed a bulging stomach secondary to aerophagia, and was vomiting. Midazolam therapy was reinstituted and continued for another 2 months by constant infusion. Thereafter, the boy was successfully weaned from artificial ventilation in 5 days under sedation with midazolam. About 12 hours after discontinuation of midazolam the boy became restless, tachycardic, again developed a bulging stomach because of aerophagia, and vomited. When the child was sedated with clorazepate by continuous infusion, the signs and symptoms disappeared. DISCUSSION: Case reports describing benzodiazepine withdrawal reaction upon discontinuation of midazolam were reviewed and compared. The symptoms observed in the children we present resemble those mentioned in the three children and two adults reported previously. Unique in the very young children in this article is the occurrence of gastrointestinal symptoms, which most likely are the result of air being swallowed secondary to severe agitation. CONCLUSIONS: Midazolam withdrawal reactions in adults and children, particularly in an intensive care unit, can be significant. Considerable caution must be taken with relatively long-term administration and abrupt discontinuation of midazolam.     

Progress in the study of IL-8

In vitro cultivation of B. burgdorferi in BSK medium results in the loss of infectivity and pathogenicity after repeated passages. To prevent this loss, a feeder layer of tibio-tarsal joint tissue derived from newborn LEW/N rats was grown on Cytodex 3 microcarriers in ESG (formerly BSKE), a novel medium developed to support the growth of both the feeder layer and B. burgdorferi. A new pathogenic isolate (FNJ) and a high passage, non-pathogenic strain (TNJ) grew well in this co-culture system with high yields of viable organism. FNJ caused no growth inhibition or visible damage to the cells in the feeder layer. FNJ remained arthritogenic for newborn LEW/N rats after 22 passages in the co-culture system, but lost its arthritogenicity after 7 passages when cultured in BSK medium. This borrelia-mammalian tissue co-culture technique presents an experimental system to study the long term interactions of B. burgdorferi with the infected host tissues in vitro, as well as facilitate diagnostic tests and vaccine development.