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A laboratory culture of Mamestra brassicae insects (MbLC) has been found to harbor a latent baculovirus infection. The latent virus was activated by feeding the M. brassicae larvae with either the closely related Panolis flammea nuclear polyhedrosis virus (NPV), or the distantly related Autographa californica NPV. Restriction fragment profiles of the activated virus DNA showed that it is very closely related, if not identical, to M. brassicae NPV. Polymerase chain reaction amplification of polyhedrin gene sequences demonstrated that the latent virus was present throughout the life cycle of the insect; eggs, larvae, pupae, and adults. We failed to detect the presence of a latent virus in a second culture of M. brassicae insects, obtained from the environment and only recently adapted to growth in laboratory conditions, and thus these insects acted as an effective negative control in all the PCR and activation experiments. Using PCR analysis of DNA isolated from dissected tissues of fourth instar MbLC larvae, latent virus sequences were only detected in the fat body. Cell lines established from the isolated MbLC fat body tissue were also shown to harbor the latent virus sequences and should prove useful in further studies to elucidate the mechanisms of latency and virus activation.

A case of acquired Brown's syndrome as a presentation of dysthyroid eye disease is described. Involvement of the superior oblique was confirmed on both CT-scan and MRI. A possible causal mechanism is discussed.

The pattern of organogenesis of the aneural soleus muscle of the 129ReJ mouse [rendered aneural by laser ablation of the lumbosacral spinal cord at 14 days in utero (during the period of primary myotube formation, but prior to the formation of secondary myotubes)] was evaluated quantitatively with spaced, serial ultrathin sections and computer-assisted morphometric analysis. Aneural muscles from 16- and 18-day gestation and newborn mice were analyzed to determine age-related changes in a number of parameters including: muscles' maximal girths, numbers of myotubes, myotube diameter distributions, and cluster frequency. Data were compared with a similar study of the organogenesis of the normal soleus muscle (Ontell et al: Am J Anat 181:279-288, 1988). Basic patterns of morphogenesis of the soleus muscle were unchanged by spinal cord ablation, and differences in development between the aneural and innervated muscles were quantitative rather than qualitative. At birth, the aneural muscle contained approximately 76% of the myotubes found in the innervated muscle (approximately 840 myotubes in the innervated muscle and approximately 640 in the aneural muscle). Evidence is presented consistent with the hypothesis that primary myotube formation is reduced by approximately 32% in the aneural muscles and that while extensive secondary myotube formation occurs (approximately 78% of the myotube present at birth in these muscles are secondary myotubes), there is a significant reduction in the number of secondary myotubes in aneural muscles. It is suggested that the reduced numbers of secondary myotubes may be related to the reduction in the number of primary myotubes, which are known to act as scaffolds for secondary myotube formation. The time course of secondary myotube formation and of cluster formation and cluster dispersal and the number of cells per cluster are similar in age-matched, innervated and aneural muscles. The absence of innervation has little effect on myotube growth until birth, when comparison of the myotube diameter distributions reveals a slight alteration in myotube diameter distributions of aneural as compared with innervated muscles.

A technique is described whereby it is possible to surgically ablate the lumbosacral spinal cord of a developing mouse fetus without interfering with fetal viability. The lumbosacral spinal cords of 14-day in utero, 129ReJ mice were ablated with a Cooper Nd-YAG laser, and the fetuses, enclosed in their membranes and attached to the uterus by their placentae, were allowed to develop in the abdominal cavity of the dam. The cytoarchitecture and the temporal pattern of organogenesis of aneural soleus muscles were studied in spaced, serial, transverse, ultrathin sections of muscles of 16- and 18-day gestation and newborn (20-day gestation) mice. At the time of surgery, the soleus muscle was a discrete mass consisting of primary myotubes and a pleomorphic population of mononucleated cells. Axon bundles and blood vessels were found at the muscle's periphery, but had not penetrated throughout the muscle mass. The organogenesis of the aneural muscle was remarkably similar to that of the innervated soleus muscle (Ontell et al., Am J Anat 181:267-278, 1988). In the aneural muscle, as in the innervated muscle, significant numbers of secondary myotubes formed all along the lengths of primary myotubes. Moreover, the time course of myotube formation, the dynamics of cluster formation and cluster dispersal, and the ultrastructural appearance of the myotubes mimicked that observed in innervated muscle. The frequency of necrotic myotubes was no greater in the aneural muscle than in the innervated soleus muscle. Myotube maturation was similar in aneural and innervated soleus muscles until 18 days gestation. However, at birth, aneural myotubes appeared to be slightly less mature than innervated myotubes. Thus, the major morphogenic phenomena that characterize the development of the soleus muscle appear to be independent of innervation.

Intra-ocular pressure was measured before and throughout airway establishment with either the laryngeal mask airway or tracheal tube. Similar measurements were made on removal of either airway and the amount of coughing noted in the first minute after removal. There was a significantly smaller increase in intra-ocular pressure (p less than 0.001) using the laryngeal mask airway, both on placement and removal, than with the tracheal tube. Postoperative coughing was significantly reduced using the laryngeal mask airway (p less than 0.001). There was a significantly greater rise in heart rate using the tracheal tube (p less than 0.01) probably related to an increased cardiovascular response. The laryngeal mask airway is recommended as an alternative to tracheal intubation in routine and emergency intra-ocular surgery.

Three patients who had extracapsular cataract extractions with intraocular lens implants developed delayed ciliochoroidal detachments, which responded to systemic steroid therapy. This rare complication may have been due to ciliary sulcus fixation of the implant. The possible mechanism and treatment are discussed.

A retrospective study was undertaken to determine whether the use of the Taylor pressure reducer during routine intracapsular cataract surgery lowered the incidence of vitreous loss. A significant reduction in the vitreous loss rate was noted. The Taylor pressure reducer is a useful device for the prevention of this complication in the Third World.

The developmental period for the parasitic stage of Romanomermis culicivorax in Culex pipiens was determined at constant and fluctuating temperatures. The median developmental times at 15, 18, 20, 27, and 32 C were 27.6, 17.2, 11.5, 7.1, and 5.8 days, respectively. The optimum temperature range for development of the parasitic stage in C. pipiens was 20 to 32 C. The threshold for development was calculated as 10.4 C, and the heat units required for development were 122.2 +/- 3.6 day-degrees. Development at fluctuating temperatures conformed to that predicted by the constant temperature data.