Antibody as carrier of 131I in cancer diagnosis and treatment.

Cell-surface localizing heterologous antibodies against mouse EL4 lymphoma, Ehrlich ascites carcinoma, and several human malignant tumors could be bound to varying amounts of 131I without interfering with the reactivity of these antibodies with their respective tumor cells. Exposure of the mouse tumor cells to radio-iodinated antitumor antibodies in vitro, or the injection of radio-iodinated antitumor antibodies into mice preinoculated with tumor cells resulted in either partial or complete tumor inhibition depending upon the amount of 131I activity carried by the antibodies. Injection of comparable amounts of the immunoglobulin alone or of 131I bound to normal globulin did not cause any tumor inhibition. Intraperitoneally injected radio-iodinated anti-EL4 antibody was found to localize preferentially in the subcutaneous transplants of EL4 lymphoma. Similar localization of intravenously injected radio-iodinated antibodies was observed in the metastases of two cancer patients.     

Temporal aspects of spatial interactions affecting stereo-matching solutions

Stereo-matching solutions minimize disparity relative to the horopter (minimum-absolute-disparity or MAD), and differences in disparity between adjacent features (minimum-relative-disparity or MRD). When placed in conflict, spatial proximity promotes MRD over MAD solutions. How does temporal proximity of neighboring features affect strength of these spatial interactions? We quantified the inter-stimulus interval (ISI) over which an unambiguous disparity pattern influenced stereo-matches for patterns with several possible solutions. Likelihood of MRD decreased as ISI increased (48.9 ms time constant) and increased as contrast was reduced for short ISIs, suggesting that monocular persistence (temporal impulse response) underlies the temporal interaction.     

Study of the Impact of Deltamethrin Impregnated Mosquito Nets on Malaria Incidence at a Military Station

Deltamethrin impregnated mosquito nets have been successfully used all over the world to combat malaria. To study the efficacy of these mosquito nets in the service conditions of Armed Forces, a field trial of Deltamethrin impregnated mosquito nets was carried out at Military Stations ‘A’ (trial station) and B (control station) between July 96 to June 99. July 96-June 97 was the pretrial year during which base line data was collected for malaria incidence. Three rounds of Deltamethrin impregnation of the mosquito nets were done in the trial station for the actual trial duration (July 97-June 99) in lieu of residual spraying. Antimalaria measures including residual spray were continued as usual in the control station. The intervention led to a significant decline in slide positivity rate and malaria incidence in the trial station. Malaria cases declined by 87% in the trial station whereas the control station noticed an increase by 75% at the end of the trial.Key Words: Deltamethrin impregnated mosquito nets, Malaria control     

Enhanced sensitivity of human oral carcinomas to induction of apoptosis by selenium compounds: involvement of mitogen-activated protein kinase and Fas pathways

Prospective studies and recent intervention trials suggest that the risk of some cancers, including respiratory tract cancers, may be inversely related to selenium (SE) intake, and this is supported by strong experimental evidence with chemical-induced animal cancer models. How this cancer-protective effect is mediated is unclear, but interference with the balance of growth/apoptosis during tumor outgrowth is one plausible hypothesis. In general, there is a correlation between the effectiveness of SE compounds as chemopreventive agents in vivo and their ability to inhibit cell growth and induce apoptosis in vitro. This study has investigated the signal transduction pathways affected by SE compounds in biopsies of normal human oral mucosa cells and human oral squamous carcinoma cells (SCCs), using a primary culture system. Two SE compounds were tested: selenodiglutathione (SDG), the primary metabolite of selenite and the most commonly used cancer-protective SE compound in animal models, and the synthetic SE compound, 1,4-phenylenebis(methylene)selenocyanate (p-XSC), one of the most potent chemopreventive pharmacological SE compounds. Three novel findings are reported: (a) SCCs were found to be significantly more sensitive to induction of apo ptosis by SDG than normal human oral mucosa cells, though the differences were marginal with p-XSC; (b) both SE compounds induced the expression of Fas ligand (Fas-L) in oral cells to a degree that correlated with the extent of apoptosis induction; and (c) both SDG and p-XSC induced the stress pathway kinases, Jun NH2-terminal kinase (JNK) and p38 kinase, at concentrations causing apoptosis; p-XSC, and to a lesser extent SDG, also activated extracellular regulated kinases 1&2 (ERKs 1&2) and protein kinase-B or Akt. To test their functional involvement, the effect of inhibiting each of these pathways on induction of apoptosis by SDG and p-XSC was determined in SCCs. Inhibiting the ERKs 1&2 or Akt pathways with specific chemical inhibitors (PD98059 or LY294002, respectively) did not affect the extent of apoptosis induced by SDG or p-XSC (with the exception of LY294002, which actually enhanced the level of induction of apoptosis by SDG). The JNK pathway appeared to be most important for induction of Fas-L and apoptosis because concentrations of SB202190 that inhibited activation of both the JNK and p38 kinase (but not ERKs 1&2) in SCC reduced the extent of induction of Fas-L and apoptosis by SDG and p-XSC, whereas lower concentrations that inhibited activation only of p38 kinase did not. This was confirmed by the fact that exogenous expression of a dominant negative deletion mutant of c-Jun (TAM67) reduced the induction of both apoptosis and Fas-L by SDG.     

Isolated coloboma of the optic nerve head: an echographic evaluation

The echographic profile of the optic nerve was studied in ten eyes with coloboma of the optic nerve head. Optic nerve dimensions measured with A-scan ultrasonography revealed an increase in the overall diameter of the nerve; B-scan echography was performed in six patients and showed excavation of the optic discs with a double-walled lining posteriorly. Additional B-scan features included widening of the anterior angle of the nerve and random perpendicular echoes in the anterior part of the nerve head. The similarities and differences in echographic pictures observed in coloboma of the optic disc and glaucomatous optic atrophy are described, and the genesis of these ultrasonographic features is discussed.     

A comparison of cycloplegic and manifest refractions on the NR-1000F (an objective Auto Refractometer).

The manifest (dry) and cycloplegic refractions of 50 eyes of 25 patients aged 8 to 28 years were studied on the Nikon Auto Refractometer NR-1000F (AR) and compared with the results of clinical refraction (CR) under homatropine and the final clinical acceptance on postmydriatic testing. Only patients in the younger age groups with low to moderate refractive errors were included in this study; high myopes and hypermetropes and patients with aphakia and mixed astigmatism were excluded. The degree of agreement for spherical equivalents, sphere components, and cylinder components was analysed separately for both cycloplegic and manifest refractions on the AR and CR. The results showed that the fixation target in the NR-1000F induces significant instrument myopia during manifest refraction in the younger patients with lower refractive errors. We recommend that caution should be exercised in interpreting manifest refractions on the AR, especially in younger patients. A cycloplegic automatic refraction would be acceptably accurate.