[The effect of antiseptic agents on the growth of mouse skin]

Using new born mouse skin slice culture, we studied the effects on certain antiseptic agents on the growth of epidermis, 0.015% approximately 1% chloromycin, 0.125 approximately 1% zinc sulfadiazine, 0.125% approximately 1.0% silver sulfadiazine markedly inhibited the expending rate of mouse skin. The higher the concentration of drugs, the higher is the inhibition rate. 10,000 U% gentamycin and 25,000U% polymyxin showed no adverse effects on skin expending rate. We conclude that during topical use of antiseptic agents (antibiotics or chemical compounds) in treatment of patients, the inhibitability of those agents on epidermis growth should be seriously considered.

Open reading frames of turnip crinkle virus involved in satellite symptom expression and incompatibility with Arabidopsis thaliana ecotype Dijon

Carmoviruses are single-stranded, single component RNA viruses that include turnip crinkle virus (TCV) and the recently discovered cardamine chlorotic fleck virus (CCFV). Full-length, biologically active cDNAs were constructed for the TCV-M isolate and the Blue Lake isolate of CCFV. Using chimeric viruses constructed between isolates of TCV that produce mild or severe symptoms when coinoculated with a virulent satellite RNA, a Glu residue at position 1,144 in the polymerase open reading frame was identified as being involved in satellite-mediated symptom expression. To analyze viral determinants involved in resistance, chimeric viruses with precisely exchanged open reading frames were produced between TCV, which does not infect the Arabidopsis thaliana ecotype Dijon (Di-0), and CCFV, which can infect Di-0, TCV with the coat protein of CCFV was able to systemically infect Di-0 although whole plant hybridizations revealed that the hybrid virus spread more slowly than either of the two parental viruses. These results indicate that the two parental viruses. These results indicate that the coat protein is an important viral determinant in the resistance of Di-0 to TCV.

Symptom attenuation by a normally virulent satellite RNA of turnip crinkle virus is associated with the coat protein open reading frame

Many satellite RNAs (sat-RNAs) can attenuate or intensify the symptoms produced by their helper virus. Sat-RNA C, associated with turnip crinkle virus (TCV), was previously found to intensify the symptoms of TCV on all plants in which TCV produced visible symptoms. However, when the coat protein open reading frame (ORF) of TCV was precisely exchanged with that of cardamine chlorotic fleck virus, sat-RNA C attenuated the moderate symptoms of the chimeric virus when Arabidopsis plants were coinoculated with the chimeric virus. Symptom attenuation was correlated with a reduction in viral RNA levels in inoculated and uninoculated leaves. In protoplasts, the presence of sat-RNA C resulted in a reduction of approximately 70% in the chimeric viral genomic RNA at 44 hr postinoculation, whereas the sat-RNA wa consistently amplified to higher levels by the chimeric virus than by wild-type TCV. TCV with a deletion of the coat protein ORF also resulted in a similar increase in sat-RNA C levels in protoplasts, indicating that the TVC coat protein, or its ORF, downregulates the synthesis of sat-RNA C. These results suggest that the coat protein or its ORF is a viral determinant for symptom modulation by sat-RNA C, and symptom attenuation is at least partly due to inhibition of virus accumulation.

[Study on skin storage at -20 degrees C]

Small pieces of fresh guinea pig or cadaveric skin, 0.3mm in thickness, were soaked in cryoprotective solution for 30 min, then were put into plastic bags and kept in -20 degrees C refrigerator. Before and after 14, 30, 45, 60, 75 days storage, the skin were sent for succinae dehydrogenase assay (modified Hershey's method) and oxygen consumption determination (microelectrolyte method). The average viabilities measured by succinated dehydrogenase and oxygen consumption were nearly 50% after 60 days storage and 30% after 75 days storage in both guinea pig and cadaveric skin. 37 times of autologous skin stored at -20 degrees C for 1-26 days were grafted on the granulation wounds with good results. Skin can be preserved viably at -20 degrees C for 45 days but not longer than 60 days. This method may be helpful for hospital which has no -80 degrees C deep freezer or liquid nitrogen container.

On deductive databases with incomplete information

In order to extend the ability to handle incomplete information in a definite deductive database, a Horn clause-based system representing incomplete information as incomplete constants is proposed. By using the notion of incomplete constants the deductive database system handles incomplete information in the form of sets of possible values, thereby giving more information than null values. The resulting system extends Horn logic to express a restricted form of indefiniteness. Although a deductive database with this kind of incomplete information is, in fact, a subset of an indefinite deductive database system, it represents indefiniteness in terms of value incompleteness, and therefore it can make use of the existing Horn logic computation rules. The inference rules for such a system are presented, its model theory discussed, and a model theory of indefiniteness proposed. The theory is consistent with minimal model theory and extends its expressive power.

[Storage temperature and skin xenograft survival]

Pieces of guinea pig skin, 0.3-0.4mm in thickness, 1.5cm in diameter, were stored at different temperatures. The skin fragments were divided into five groups: (1) fresh skin; (2) skin stored at 4 degrees C for 48hr; (3) skin stored at -20 degrees C for 48hr; (4) skin stored at -80 degrees C for 48hr; (5) skin stored at -196 degrees C for 48hr. The cryoprotective agent was the same in all groups except group 2. The experimental skin was grafted on both sides of the back of anesthetized mice, two pieces of skin of the same group for one mouse. The grafted skin survival was determined by daily observation. The skin was considered as rejected if necrosis took place in 80% of the grafted skin. Grafted skin biopsy was performed for pathological examination. The results showed that the survival days of stored skin xenografts were prolonged as the stored temperature lowered. The pathological changes (neutrophil infiltration, thrombosis of small vessels, necrosis of epidermal and dermal cells) were mild and delayed as the stored temperature lowered. So low temperature may decrease the antigenicity of the stored skin.

[The effects of different storage temperatures on epidermal Langerhans cells]

The skin from fresh human cadavers and guinea pigs was stored in 4 degrees C, -20 degrees C, -80 degrees C and -196 degrees C deep freezing for six different periods (1, 2, 3, 5, 7 and 14 days). The number and morphology of Langerhans cells (LC) were observed using Juhlin's ATP-ase dye method. It was found that the epidermal LC of cryopreserved skin decreased significantly in number, and there was a marked change in shape, as compared with fresh skin grout (P < 0.01), except for those in 4 degrees C groups (for 1, 2, 3 days). The mean value of LC in -196 degrees C group, which was 40%-50% of that of fresh skin, was the lowest among all the groups. The number of LC dropped most rapidly in the -196 degrees C group after one day freezing. The changes in LC in the stored skin may play an important role in prolongation of rejection time after transplantation.

Integration of traditional and modern methods in the identification of AFB cultures isolated from clinical specimens of patients with skin diseases

This article reports the identification of 57 AFB cultures isolated from clinical specimens by using traditional methods (TM, including biochemical and cultural methods) and modern ELISA with monoclonal antibody (McAb-ELISA) and nested primer gene amplification assay (NPGAA). The representive AFB culture M. A1, A7, A19, A21 and A22) isolated from human lepromas were identified as new species by TM and it was shown that they were not identical to M. leprae by McAb-ELISA and NPGAA. Among another set of samples (M. S17, S1, S2, S2R, S7, S29), M. S17 was identical to M. scrofulaceum as assessed by TM only, while the others were found to be similar to M. tuberculosis and different from M. leprae using TM and McAb-ELISA, and identical to M. tuberculosis with NPGAA. The authors conclude that TM and MM are very useful for identifying mycobacteria, while MM was much more sensitive and specific than TM. The selection and use of these methods depends on practical need.

Migration of activated lymphocytes when adoptively transferred into cannulated rat brain

Migration of fluorescent DNA-labeled or 111Indium-labeled activated lymphocytes was studied in normal rat brain bearing surgically implanted cannulas. The migration of allogeneic cytotoxic T lymphocytes (CTL), derived from the DA rat (DA anti Fischer CTL), and of syngeneic concanavalin A (ConA)-activated lymphocytes (Fischer Con A blasts), was determined in Fischer rats between 2 h and 7 days post instillation into parietal brain. Whole body nuclear imaging indicated that the majority of the radiolabeled lymphocytes, either syngeneic or allogeneic, were present in the brain at 2 and 18 h. Autoradiography of brain slices demonstrated that label was located throughout the brain and in both hemispheres at all time points. By direct tissue radioassay, approximately 60% of the injected dose was present between 2 and 18 h; this decreased to 18% by day 7. By fluorescence microscopy, large numbers of lymphocytes were visible up to 3-4 days. The lymphocytes traveled from the instillation site into both cerebral hemispheres primarily following white matter tracts. Preferential localization of fluorescently labeled lymphocytes was seen in the corpus callosum, internal and external capsules, anterior commissures, lateral olfactory tracts, white matter connections in the caudate and putamen, mammillothalamic and optic tracts. Overall, gray matter contained fewer cells although perivascular spaces within it had high concentrations of cells, indicating these spaces may act as points of egress.

Intracranial administrations of single or multiple source allogeneic cytotoxic T lymphocytes: chronic therapy for primary brain tumors

Previous investigations by our group demonstrated the efficacy of single source allogeneic cytotoxic T lymphocytes (CTLs) given multiple times in reducing or curing tumor burden in the rat 9L gliosarcoma model. In this study, the lack of toxicity to normal brain when single source allogeneic CTLs were intracranially administered multiple times is documented. Additionally, the efficacy and lack of toxicity of allogeneic CTLs from multiple sources, each given once is documented. CTLs sensitized to Fischer antigen were prepared from major histocompatibility complex incompatible DA, PVG, Sprague-Dawley and Wistar-Furth rat lymphocytes. CTLs from multiple donors were administered one time each to Fischer rats bearing established 9L tumor at staggered intervals over a two week period and survival was monitored in relation to a sham treated group. Additional groups of nontumor-bearing rats received either multiple source allogeneic CTLs or single source DA anti Fischer CTLs in the same treatment regimen. Histological evaluation of the nontumor-bearing brains receiving either single or multiple source allogeneic CTL infusions showed minimal localized brain damage confined to the cannulation tract. No neuronal loss or inflammatory reaction was seen either adjacent to or remote from the administration site. Brains from the long-term survivors of the tumor-bearing animals showed no residual neoplasm; the instillation site had focal sterile abscesses; gliosis and neuronal loss did not extend into adjacent brain. The safety and potential of chronic, local allogeneic CTL administration, derived from multiple donors, as adjuvant local therapy for brain tumors was demonstrated.

Systemic chemotherapy combined with local adoptive immunotherapy cures rats bearing 9L gliosarcoma

Survival of Fischer rats bearing 9L gliosarcoma in the brain was measured to determine the efficacy of 1) systemically administered chemotherapy with local adoptive immunotherapy (chemo-adoptive immunotherapy) or 2) systemically administered chemo-immunotherapy. Winn assays, where tumor instillation coincided with the start of treatment, and one-week established tumor assays were conducted. Survival of chemo-adoptive immunotherapy treated groups given intraperitoneal cyclophosphamide and intracranial lymphokine activated killer cells and recombinant Interleukin-2 was significantly extended when compared to sham treated control groups, to groups given chemotherapy with intraperitoneal cyclophosphamide, and to groups treated by local adoptive immunotherapy with intracranial lymphokine activated killer cells and Interleukin-2. The killer cells were generated from spleens of donor rats that either had or had not been given cyclophosphamide 24 h earlier. Long-term survivors (9/39), sacrificed at day 70, were obtained only in the chemo-adoptive immunotherapy treated groups; 7/39 had no histologic evidence of tumor and had focal sterile abscesses at the site of killer cell instillation. Average group weight plotted over time showed that there was acceptable toxicity with chemo-adoptive immunotherapy; the toxicity was identical to that obtained with systemic cyclophosphamide treatment. In contrast, survival of chemo-immunotherapy treated groups given systemic cyclophosphamide and Interleukin-2 was not significantly extended from groups which were sham treated or treated only with systemic Interleukin-2. Rapid decline of average group weight plotted over time and early deaths following chemo-immunotherapy treatment indicated that the regimen was toxic. The effect of cyclophosphamide administration on the splenocytes of donor rats and the LAK cells generated from them was determined by in vitro studies analyzing cell number, viability, phenotypic expression and cytotoxicity against 9L tumor. In the treatment of this intracranial neoplasm, the beneficial effects of cyclophosphamide were determined to occur in situ in the tumor-bearing host. No benefit resulted from cyclophosphamide treatment of donor rats that supplied splenocytes for LAK cell production.