Work in progress. Intraoperative neurosurgical ultrasound: localization of brain tumors in infants and children

Intraoperative real-time ultrasonic sector scanning was performed through the unincised dura mater or the intact brain surface of eight patients (aged six months to 13 years), each of whom had a previously documented mass lesion (four supratentorial, three infratentorial, one intraventricular). In each case, there was a clear definition of the location, configuration, and tissue consistency of the mass. With the exception of a choroid plexus papilloma, all lesions demonstrated both solid and fluid components. The location of a subcortical parietal lobe mass (ependymoma) was apparent only by prior sonography. All neoplastic tissue of one cerebellar astrocytoma that was identified at gross examination was removed, but additional intraoperative scanning following removal of the neoplasm suggested the presence of residual abnormal tissue. This was confirmed during further exploration, and additional gross tumor tissue was excised.     

Quantitative assessment of vegetation structural attributes from aerial photography

Cover of vegetation understorey and overstorey was determined from aerial photography at 1:25 000 and 1:40 000 scales by a grid sampling technique. Models were developed relating values of aerial cover to field cover as determined by intensive field measurement. The influence of photo-scale, photo colour, the angle of the image, shadow, the hiatus between aerial and field sampling, crown width, crown height, proportion of dead trees, drought prior to aerial sampling, land type, previously cleared vegetation and incline on explanatory models was also examined. The only variables that could be clearly interpreted as influencing the models were vegetation height, photo-scale and land type. Only the latter two variables are useful for predictive models. The smaller the scale of photography the greater the exaggeration of the aerial image of tree crowns. This probable result of photo graininess would be most significant when tree crowns are small, an inverse surrogate of tree height. Two-phase models were developed for predicting basal area and biomass from aerial cover. In most instances models were successful for predicting overstorey and understorey cover and for predicting total basal area and biomass. The technique offers a powerful and cost-effective method of assessing vegetation change over long time periods in a way that no other technique can duplicate.     

Subconjunctival mitomycin C for the treatment of ocular cicatricial pemphigoid

PURPOSE: The authors performed a prospective evaluation of the efficacy of treating ocular cicatricial pemphigoid (OCP) with subconjunctival mitomycin C. DESIGN: Unmasked, prospective, internally controlled case series. METHODS: Patients were eligible for treatment with subconjunctival mitomycin C under three criteria: (1) significant complications of systemic immunosuppressant therapy; (2) markedly asymmetric conjunctival disease; and (3) end-stage OCP. All patients received monocular subconjunctival injections of 0.25 ml of 0.2 mg/ml mitomycin C to both the superior and inferior bulbar conjunctivae in the eye with the more severe disease. RESULTS: Nine eyes of nine patients (mean age, 74 years) were treated with subconjunctival mitomycin C to the more-involved eye and were followed for a mean of 23.5 months (range, 12-40 months). Eight of nine patients showed quiescence of their OCP in the treated eye based on serial evaluation of conjunctival cicatrization and grading of conjunctival erythema. Five of the nine untreated eyes showed progression of the conjunctival disease. One patient required concomitant systemic immunosuppressive therapy after subconjunctival mitomycin C. Two patients underwent successful visual rehabilitative surgery in the mitomycin C-treated eye. CONCLUSION: The use of subconjunctival mitomycin C may be effective in preventing progression of conjunctival cicatrization and erythema in patients with OCP. No complications of mitomycin C treatment were noted. Long-term follow-up and further investigation into the efficacy of subconjunctival mitomycin C in the management of OCP is warranted.     

Effects of five natural gonadotropin-releasing hormones on cell suspensions of marine bivalve gonad: stimulation of gonial DNA synthesis

Gonadotropin-releasing hormones (GnRH) constitute a family of neuropeptides which are important regulators of reproduction in vertebrates. The effect of mammalian GnRH (mGnRH), salmon GnRH, chicken GnRH-I, chicken GnRH-II, and lamprey GnRH-I on [3H]thymidine incorporation into DNA of dissociated gonadal cells of marine bivalves has been studied. The incorporation of [3H]thymidine is linear between 1.5 and 8 h of incubation. All five GnRHs significantly increased DNA synthesis in gonial cells of Crassostrea gigas. The maximal activation was about of 135-140% above control. The activation is dose dependent, over the range 10(-11) to 10(-6) M, but is modulated by the physiological condition of the cells and the stage of sexual maturity of the gonad. mGnRH has also a mitogenic effect in dissociated mantle cells of Mytilus edulis. The effect of mGnRH is blocked by a GnRH antagonist ([D-pGlu1,D-Phe2, D-Trp3,6]GnRH, 5 x 10(-6)M) in C. gigas as well as in M. edulis, suggesting that the GnRH action in the gonad is mediated by specific receptors for GnRH or GnRH-like peptides. The existence of GnRH-immunoreactive neurons and fibers in the cerebral and pedal ganglia of M. edulis was demonstrated by immunocytochemistry. They are located principally in the anterior internal area of the cerebral ganglia, close to the cerebral commissure and in the posterior part of the pedal ganglia. The presence of GnRH-responsive cells and GnRH-like immunoreactive material suggests that peptides of the GnRH-like family are present and functional in bivalve molluscs.     

Three distinct D-amino acid substitutions confer potent antiangiogenic activity on an inactive peptide derived from a thrombospondin-1 type 1 repeat

Mal II, a 19-residue peptide derived from the second type 1 properdin-like repeat of the antiangiogenic protein thrombospondin-1 (TSP-1), was inactive in angiogenesis assays. Yet the substitution of any one of three L-amino acids by their D-enantiomers conferred on this peptide a potent antiangiogenic activity approaching that of the intact 450-kDa TSP-1. Substituted peptides inhibited the migration of capillary endothelial cells with an ED50 of 8.5 nM for the D-Ile-15 substitution, 10 nM for the D-Ser-4 substitution, and 0.75 nM for the D-Ser-5 substitution. A peptide with D-Ile at position 15 could be shortened to its last seven amino acids with little loss in activity. Like whole TSP-1, the Mal II D-Ile derivative inhibited a broad range of angiogenic inducers, was selective for endothelial cells, and required CD36 receptor binding for activity. A variety of end modifications further improved peptide potency. An ethylamide-capped heptapeptide was also active systemically in that when injected i.p. it rendered mice unable to mount a corneal angiogenic response, suggesting the potential usefulness of such peptides as antiangiogenic therapeutics.