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Notes: An enzymatic debriding preparation was formulated with purified enzyme derived from a crude pineapple stem extract. The primary component of this preparation was the sulfhydryl protease ananain which represented ≥85% of the proteolytic activity. The remaining proteolytic activity in the preparation was contributed by a co-purifying homologous cysteine protease comosain. Taken together these two proteases provided a protein purity of greater than 95% as judged by sodium dodecyl sulfate polyacrylamide gel electrophoresis. This ananain-based enzyme preparation exhibited both gelatinolytic and fibrinolytic activity in vitro. Ananain-based enzyme preparation was formulated in a hydrophilic cream vehicle at concentrations ranging from 115 to 260 U/gm vehicle. Ananain-based enzyme preparation formulated in this fashion is referred to as Vianain debriding agent. Vianain was applied to partial-thickness cutaneous burn wounds produced in the skin of domestic pigs. A maximum of two 4-hour applications of Vianain provided complete debridement of eschar from the partial-thickness burn wounds as judged by light and electron microscopic analyses of biopsy specimens harvested before and after debridement. Wounds debrided with Vianain exhibited more rapid reepithelialization as compared with wounds that were not debrided. Wounds on pigs that were hyperimmunized to ananain-based enzyme preparation before burning and debridement with Vianain exhibited a similar enhancement in reepithelialization as compared with wounds treated with vehicle alone. The capacity of Vianain to debride necrotic tissue was also evaluated in a guinea pig ischemic ulcer model. Full-thickness ischemic lesions were created on the back of guinea pigs. Vianain was applied to the hardened necrotic tissue for 6 hours per day for up to a maximum of 5 days. Complete debridement of these wounds was accomplished within 4 to 5 days. Treatment of ischemic cutaneous ulcerations in this animal model with two commercially available enzyme-debriding agents provided little or no debridement of the necrotic tissue. In vitro, Vianain treatment of surgically debrided human tissue samples, obtained from patients with burn injury or cutaneous ulcers, showed that the protease preparation was effective in rapidly digesting these necrotic tissues.

Notes: Abstract: Specific binding of [35S]t-butylbicyclophosphorothionate (TBPS) to membranes from cerebral hemispheres of adult rat and chicken was determined over a range of radioligand concentrations from 0.25 to 500 nM. Scatchard plots of these data were curvilinear and non-linear regression analysis indicated binding to two sites that differ in affinity. For rat cerebrum, KD(1)= 1.15 nM, Bmax(1) 0.085 pmol/mg; KD(2)= 232 nM, Bmax(2)= 16.9 pmol/mg. For chicken cerebrum, KD(1)= 1.39 nM, Bmax(1)= 0.111 pmol/mg; KD(2)= 166 nM, Bmax(2)= 17.6 pmol/mg. This multiplicity of [35S]TBPS binding was further confirmed when unlabeled TBPS or picrotoxinin displaced radioligand. The displacement curves were biphasic and yielded Hill coefficients from 0.65 to 0.70. These displacement curves were also resolved into two components with distinct IC50 values for unlabeled TBPS (rat, 1.55 and 271 nM; chicken, 2.40 and 224 nM). The IC50 values were similar to the dissociation constants obtained from equilibrium binding measurements.

Notes: Abstract: The role of t-butylbicyclophosphorothionate (TBPS) as an antagonist of γ-aminobutyric acid (GABA) was studied with primary cultures of neurons from the chick embryo cerebrum. The addition of GABA stimulated the uptake of 36Cl− by neurons and the dose dependence of this effect followed hyperbolic kinetics with a K0.5= 1.3 μM for GABA. TBPS proved to be a potent inhibitor of GABA-dependent Cl− uptake (IC50= 0.30 μM). Analysis of the kinetics of this process revealed that TBPS is a noncompetitive inhibitor (Ki= 0.15 μM) with respect to GABA. Scatchard analysis of direct binding of [35S]TBPS to membranes isolated from neuronal cultures gave curvilinear plots. These could be resolved by nonlinear regression methods into two components with KD values of 3.1 nM and 270 nM. The TBPS binding constant for this lower affinity site agreed well with the IC50 and Ki values for inhibition of Cl− flux, suggesting that this site is physiologically relevant to GABA antagonism. GABA was a noncompetitive displacer of [35S]TBPS binding to the lower affinity site. The Ki value for this displacement by GABA (1.7 μM) was comparable to the value for GABA enhancement of Cl− flux. The binding of [35S]TBPS to its low-affinity site on neuronal membranes was ninefold higher in the presence of Cl− than with gluconate, an impermeant anion. The rank order for anion stimulation of [35S]TBPS binding was Br−≧ SCN− 〉 Cl−≧ NO−3 〉 I− 〉 F− 〉 gluconate. The EC50 value for Cl− enhancement of [35S]TBPS binding (160 mM) agreed well with the Km for Cl− influx via GABA-gated channels (140 mM). These results indicate that TBPS acts as a GABA antagonist via direct blockade of neuronal Cl− channels. A minimum density of 6.5 × 104 chloride channels per neuron was obtained from TBPS binding at saturation.

Notes: Spores of a haplosporidan infecting Teredo navalis Linnaeus have been described as morphologically indistinguishable from spores of Haplosporidium nelsoni. To test the hypothesis that these organisms are conspecific, a colloidal gold immunoassay was used to compare antigenic characteristics of the spores from both hosts. Rabbit antibody to formalin-fixed spores from T. navalis was tested against paraffin sections of Crassostrea virginica infected with spores of H. nelsoni and against paraffin sections of infected 7″. navalis. Application of primary antibody was followed by addition of affinity purified goat anti-rabbit IgG coaled on 5-nm colloidal gold particles. The reaction was enhanced by precipitation of metallic silver; a positive reaction appeared as a dark brown to black signal at the site of each antigen-antibody complex. Haplosporidium nelsoni spores did not react when assayed with the antibody made to spores from T. navalis. Spores from infected T. navalis tissue reacted positively with rabbit antibody. This result indicates that the spores from the 2 hosts are antigenicaliy distinct and suggests that they are different species.

Notes: . Haplosporidium nelsoni is a pathogen of the eastern oyster, Crassostrea virginica, along the middle Atlantic coast of the U.S. Genomic DNA was extracted from H. nelsoni plasmodia and small subunit (SSU) rDNA was amplified by PCR, cloned and sequenced. The sequence of H. nelsoni SSU rDNA was aligned with that of another haplosporidian, Minchinia teredinis, and with SSU rDNA data of C. virginica and various protists in GenBank. A 21-base oligonucleotide unique to H. nelsoni, designated MSX1347, was commercially synthesized and tested for sensitivity and specificity. In dot blot hybridizations the probe detected 100 pg of cloned H. nelsoni rDNA and the presence of H. nelsoni in 1 μg of genomic DNA from an infected oyster. It did not hybridize with 1 μg of genomic DNA from uninfected C. virginica or with cloned SSU rDNA of M. teredinis. The probe was further tested for specificity with in situ hybridizations on AFA-fixed, paraffin-embedded tissue sections. The probe hybridized well with H. nelsoni plasmodia and immature spores, but poorly with mature spores. The probe did not hybridize with oyster tissue, with other common oyster parasites such as P. marinus or Nematopsis sp., or with the haplosporidians Haplosporidium louisiana from mud crabs (Panopeus spp.), Haplosporidium costale from C. virginica or M. teredinis from shipworms (Teredo spp.).

Notes: Some magnetic properties of amorphous ferromagnets are well described within the random-anisotropy real-space model. This model assumes that the neighboring spins are ferromagnetically coupled with each other, and that there is a local magnetic anisotropy whose axes are correlated over a small length Ra due to short-range structural order. The system is characterized by a small parameter λ∼R2aK/A which depends on temperature and on the concentration of magnetic atoms via the local anisotropy K and exchange constant A. In zero magnetic field the local magnetization smoothly rotates over the solid with a characteristic length Rf =Ra/λ2. The zero-field susceptibility is very sensitive to the exchange, the anisotropy, and the amorphous structure: χ∝A3K−4R−6a. The magnetization law in approaching saturation (M→M0) is universal (M0−M)∝1/(H)1/2 for H〈2A/M0R2a. These and other predictions of the model seem to be in a good agreement with many recent experimental results.

Notes: Background/aims: Efficacy evaluation of new antipsoriatic drugs is difficult in the absence of good animal models. In the experimental treatment of psoriasis plaques, the administered dose of new drugs has to be kept at a minimum for safety reasons. The object is to introduce an extracorporeal system for experimental drug application based on the Alzet osmotic pump.Methods: The system consists of four Alzet pumps from which the drug is delivered intradermally to lesional skin via a 21-gauge needle. Infusion may be continued for up to 2 weeks. Infusion sites are evaluated clinically by the scoring of scaling, erythema and thickness. Evaluation is also based on scoring of the cardinal microscopic features of psoriasis on a 0 to 19 weighted scale.Results/conclusion: The delivery system was screened using a number of drugs and found useful. The system is cheap and easy to operate.