Development of Chronomers tm for narcotic antagonists

The object of this program is to prepare a bioerodable naltrexone delivery system which can be implanted subcutaneously in humans and which can relieve the narcotic antagonist over 1-6 months at relatively constant and sufficient rates to block the euphoric effect of morphine based drugs. The system is composed of naltrexone uniformly dispered in a solid hydropholic CHRONOMER TM matrix which undergoes predictable surface erosion when exposed to an aqueous medium. Kinetic studies in vitro have been carried out during the course of the program to determine the best composition for the system. Toxilogical studies conducted at ALZA during the past 2 years have not revealed limiting adverse effects of either the CHRONOMER TM materials or their hydrolysis products. The tail-flick test procedure was used to measure the effectiveness of naltrexone to antagonize the analgesis of morphine in rats. Naltrexone infused intravenously at doses of 4 and 16 ug/kg/hr resulted in, after 6 hours, 54 and 89% antagonism, respectively, against a 63.5% effective dose of morphine. Perliminary sterilization studies showed that no adverse effects to CHRONOMER TM/naltrexone systems occurred after exposure to 2.5 or 5.0 mrads of 60CO irradiation.     

Tuberculosis among Filipino patients with systemic lupus erythematosus

A retrospective review of the clinical records of 54 patients with systemic lupus erythematosus (SLE) and documented tuberculosis (TB) infection seen at the University of Santo Tomas Hospital was accomplished. There were 53 women and one man, with a mean age of 32.2 +/- 10 years and a total of 57 TB occurrences. Pulmonary involvement was recorded in 42 (74%): upper lungfield in 25, mid to lower lungfield in 7, and miliary pattern or diffuse infiltrates in 10. TB arthritis was noted in 8, osteomyelitis in 4, and soft tissue abscesses in 4. Central nervous system involvement consisted of brain abscesses (tuberculomas) in two and meningitis in one. Two patients each had TB lymphadenitis, genitourinary TB, ileocecal TB, and TB peritonitis. Hepatobiliary and cutaneous TB occurred in one patient each. Eight of 10 patients with disseminated or miliary TB died primarily of respiratory failure; six of these eight patients also had some form of extrapulmonary involvement. Using the Wilcoxon rank-sum test, there were significant differences in the mean SLE Disease Activity Index (SLEDAI) and Severity of Disease Index (SDI) scores between those with limited TB (SLEDAI 24 +/- 7 SD; SDI 19 +/- 18 SD) versus those with extensive TB (SLEDAI 41 +/- 16 SD; SDI 36 +/- 21 SD), P < .05. There was no significant difference in the average daily prednisone dose (mg) between those with limited TB (25 +/- 17 SD) versus those with extensive TB (31 +/- 16 SD). The contributory role of tuberculous infection in the morbidity and mortality of patients with SLE must be emphasized, especially in areas endemic for TB.     

Thermally induced molecular disorder in human stratum corneum lipids compared with a model phospholipid system; FT-Raman spectroscopy

The molecular basis of lipid packing in human stratum corneum and a model phospholipid system has been studied as a function of temperature using Fourier Transform (FT) Raman spectroscopy. Thermally induced molecular rearrangements of the model lipid system, dipalmitoylphosphatidyl choline (DPPC), and stratum corneum were investigated using FT Raman spectroscopy coupled to a heating chamber. Spectra were recorded for a range of sample temperatures and the results for the two systems were compared, producing previously unreported information of the thermal behaviour for the different systems. Discrete thermal events were recorded for both systems by plotting band separation of the lipid v(CH2) symmetric and asymmetric stretching modes against temperature. The main thermal events observed for DPPC included a 'pre-melting' between 37 and 39 degrees C, the main transition observed between 41 and 42 degrees C, a 'post-transition' between 42 and 43 degrees C and three minor transitions at 58-60, 65-70 and 75-80 degrees C. No evidence was found for the pre-transition of DPPC, previously observed at 34-35 degrees C. The main transitions for human stratum corneum were observed at 35-45, 55, 72 and 83 degrees C, measured from lipid CH2 stretching and bending vibrations. The keratin thermal transition at about 100 degrees C exerted little effect on the lipid bands and no characterisable structural changes were reflected in the keratotic bands.     

Canine bronchial sustained contraction in Ca2+-free medium: role of intracellular Ca2+

We evaluated whether cartilage was a source of Ca2+ and the possible role of Ca2+ recycling in the sustained bronchial contraction (SBC) induced by carbachol (Cch) in Ca2+-free medium. Canine first-order bronchi were studied with cartilage and epithelium (+CAR + EPI) and without these structures individually (-CAR + EPI and +CAR - EPI) or together (-CAR - EPI). After cartilage removal (-CAR - EPI or -CAR + EPI) Cch produced a transient contraction in Ca2+-free medium. Removal of the epithelium alone had minor effects on the magnitude of the SBC but increased the effect of removal of cartilage to diminish the SBC. Bronchial strips with cartilage were able to respond to Cch with lower Ca2+ concentrations (10-100 microM) than could dissected preparations. Preincubation with BAY K 8644 (30-1000 nM) or 60 mM KCl or -CAR - EPI tissues converted the transient contractions to Cch in Ca2+-free medium to sustained contractions. In microelectrode studies, 50 nM Cch induced membrane oscillations in solutions with 2.5 mM Ca2+ in bronchial preparations, plus or minus cartilage, and in undissected tissues in Ca2+-free medium but not in -CAR - EPI tissues. Preincubation with 1 microM BAY K 8644 in Ca(2+)-free medium restored these oscillations in -CAR - EPI tissues. The release of 45Ca2+ from cartilage was too rapid to provide a reservoir of Ca2+ to support multiple SBCs in Ca2+-free medium. Moreover, in the Ca2+-free medium (with 10 nM Ca2+ after tissue +CAR + EPI incubation) excitatory junction potentials rapidly disappeared. Addition of 1 microM nifedipine or 1 mM EGTA during the SBC of +CAR + EPI tissues produced complete relaxation. A transient contraction to Cch occurred with prior addition of nifedipine. Inhibition of the sarcoplasmic reticulum Ca2+ pump by tissue incubation with cyclopiazonic acid (CPA; 10 microM), or briefly with 1 mM EGTA significantly diminished the SBC induced by Cch in Ca2+-free medium. CPA and EGTA together abolished the Cch-induced SBC. Thus, cartilage plays a more complex role than as a Ca2+ reservoir to support the SBC induced by Cch in Ca2+-free solution; its removal affects the process supporting SBCs involving intracellular Ca2+ storage and Ca2+ entrance through voltage-dependent channels.     

Provisional bilateral symmetry in Xenopus eggs is established during maturation

Dorsal-ventral patterning in the Xenopus egg becomes established midway through the first cell cycle during a 30 degree rotation of the subcortical yolk mass relative to the egg cortex. This 'rotation of symmetrisation' is microtubule dependent, and its direction is thought to be cued by the usually eccentric sperm centrosome. The fact that parthenogenetically activated eggs also undergo a directed rotation, despite the absence of a sperm centrosome, suggests that an endogenous asymmetry in the unfertilised egg supports the directed polymerisation of microtubules in the vegetal cortex, in the way that an eccentric sperm centrosome would in fertilised eggs. Consistent with this idea, we noticed that the maturation spot is usually located an average of more than 15 degrees from the geometric centre of the pigmented animal hemisphere. In parthenogenetically activated eggs, this eccentric maturation spot can be used to predict the direction of rotation. Although in most fertilised eggs the yolk mass rotates toward the sperm entry point (SEP) meridian, occasionally this relationship is perturbed significantly; in such eggs, the maturation spot is never on the same side of the egg as the SEP. In oocytes tilted 90 degrees from upright during maturation in vitro, the maturation spot developed 15 degrees or more from the centre of the pigmented hemisphere, always displaced towards the point on the equator that was up during maturation. This experimentally demonstrated lability is consistent with an off-axis oocyte orientation during oogenesis determining its eccentric maturation spot position, and, in turn, its endogenous rotational bias.     

Entamoeba histolytica trophozoites: a surface-associated cysteine protease

The purpose of this work was to define cell surface proteases on Entamoeba histolytica trophozoites. Molecular sizes of 2-mercaptoethanol-activated proteases were determined in several ameba cell fractions. Inhibited proteases were resolved in SDS-polyacrylamide gels and then defined by their ability to digest bovine albumin during electrophoretic migration of ameba bands through a stacking gel containing albumin. This second gel revealed nine gaps of digestion along the horizontal albumin line corresponding to proteases with molecular weights of 195, 175, 150, 124, 102, 70, 45, 36, and 28 kDa. The 70-kDa protease proved to be the most active in plasma membrane, in whole membrane fractions, and in total extracts of ameba. This protease appears to be an integral membrane component as it was reconstituted in an artificial membrane system in its active form, as well as because it was present on the surface of glutaraldehyde-fixed amebas. These results demonstrate that amebic trophozoites contain on their surface a very active protease, which may play a role in the digestion of host components.