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PubMed1977

Studies on the embryogenesis of the tapeworm Shipleya inermis Fuhrmann, 1908 using transmission and scanning electron microscopy.

Scanning electron micrographs (SEM) are shown of the scolex, microtrichs, and the submucosal capsule formed by the worm. The course of development of the outer capsule and the outer envelope from the early preoncosphere to the mature oncosphere is followed by SEM and (in part) transmission electron microscopy. Three phases of development of the outer envelope (OE) were noted: (1) early preoncosphere with OE with a relative smooth outer surface, (2) the development of surface lamellae and (3) the formation of a dendritic area distal to the lamellae; all of the organelles appear to be secretory. Stereoscopic pairs of cryofractured developmental stages are used to aid understanding of the OE. Transmission electron micrographs are used to corroborate the SEM micrographs.

Cestoda↗
PubMed1997

Effect of IL-6 on tumor cell invasion of vascular endothelial monolayers.

The effect of interleukin-6 (IL-6) on the invasive capacity of B16-F1 mouse melanoma cells into vascular endothelial monolayers was examined, and an in vitro assay system for the quantitative determination of tumor cell invasiveness, using confocal microscopy with a fluorescence image analyzer, was developed. First, the invasive capacity of B16-F1 mouse melanoma cells against bovine vascular endothelial monolayers was estimated; then, the gap junctional intercellular communication (GJIC) of endothelial cells was examined. Treatment of endothelial cells with IL-6 resulted in a remarkable increase in the invasion of tumor cells into the endothelial monolayer, which was found to be significant from 25 ng/ ml, and peaked at levels of more than 50 ng/ml. This stimulatory effect of IL-6, which was observed from 3 h after the initiation of treatment and lasted for up to 24 h, was abolished by the addition of the anti-IL-6 antibody. Although phase-contrast microscopy did not reveal any morphological changes in the endothelial cells following treatment with 25-200 ng/ml IL-6 for 24 h, the GJIC was observed to be significantly decreased. These findings indicate that the invasive capacity of tumor cells into endothelial cells is affected by IL-6.

Analysis of Variance↗
PubMed2001

Apoptosis, necrosis, and cell proliferation induced by S-(1,2-dichlorovinyl)-L-cysteine in primary cultures of human proximal tubular cells.

Apoptosis, necrosis, and cell proliferation induced by S-(1,2-dichlorovinyl)-L-cysteine (DCVC), the cysteine conjugate of the environmental and occupational contaminant trichloroethylene, were studied in primary cultures of human proximal tubular (hPT) cells. Cells from male and female donors were incubated with a range of concentrations of DCVC (10 to 1000 microM) for up to 48 h, and assessments of cellular morphology (phase-contrast microscopy), necrosis (lactate dehydrogenase (LDH) release), apoptosis(cell cycle analysis, annexin V staining, and caspase activation), and proliferation (cell cycle analysis and DNA synthesis) were made. Time- and concentration-dependent changes in cellular morphology, including elongation of cell shape, formation of intracellular vesicles, and formation of apoptotic bodies, were observed. Significant increases in LDH release occurred in hPT cells incubated with < or =100 microM DCVC for at least 24 h. hPT cells from males were modestly more sensitive to DCVC than those from females, with maximal LDH release of 78 and 65% in cells from males and females, respectively. Flow cytometry analysis of propidium iodide-stained and DCVC-treated hPT cells showed that apoptosis occurred at markedly lower concentrations (10 microM) and at much earlier incubation times (2 h) than necrosis. A small increase was also noted in the percentage of cells in S-phase after a 4-h treatment with as little as 10 microM DCVC, suggesting that cell proliferation was stimulated. This was supported further by increased DNA synthesis. These results show that DCVC causes apoptosis and enhances cell proliferation in hPT cells at environmentally relevant doses and at earlier time points and lower concentrations than necrosis.

Adult↗
PubMed1994

Airborne concentrations of asbestos in non-occupational environments.

Concentrations of asbestos in air were determined from analysis of samples collected in over 300 buildings involved in litigation. Samples were collected by certified industrial hygienists and analysed in certified laboratories by transmission electron microscopy. Building group mean concentrations of asbestos in building air inhaled by occupants were generally less than 0.0005 f ml-5 > 5 microns (90th percentile). At these concentrations the risk from asbestos exposure would be very low for building occupants. Another data set was obtained from the maintenance logs kept by owners of buildings containing asbestos fireproofing and subject to Operations and Maintenance Programmes to evaluate asbestos inhalation risk to maintenance workers. The logs were kept to document protective measures and maintenance personnel exposures during 1991-1992. Data are presented for one commercial building, which is typical of data for three additional commercial buildings and a medical centre. All samples were evaluated by the NIOSH 1400 protocol for sampling and analysis by phase contrast microscopy. Operations and maintenance precautions to reduce dust emission were modest; they included spraying of ceiling tiles with amended water, HEPA vacuuming tile edges before entry and after tile replacement, respirator usage and careful work. Negative pressure containment was not used. In this building personal exposures in electrical/plumbing work ranged from 0.000 to 0.035 f ml-1 > 5 microns in length (average work time of one job was 118 min); the 8-h TWA was 0.0149 f ml-1 > 5 microns.(ABSTRACT TRUNCATED AT 250 WORDS)

Air Pollutants↗
PubMed1986

Rat spermatogenesis in vitro traced by quantitative flow cytometry.

In vitro differentiation of germ cells in rat seminiferous tubule segments at stages II-III of the epithelial cycle was studied. DNA flow cytometry was used for quantitation of absolute cell numbers from the cultured tubule segments that were compared to freshly isolated stages of the cycle, as identified by transillumination stereomicroscopy of the seminiferous tubules and phase-contrast microscopy of live cell squashes. Spermatogonia and spermatocytes from stages II-III showed normal morphological differentiation during 7 days in vitro. Round spermatids differentiated to Step 7 of spermiogenesis but Step 16 spermatids failed to develop. Acid phosphatase activity in the spermatogenic cells changed normally during the culture. As compared with freshly isolated control tubule segments, 35% of round spermatids and 42% of pachytene spermatocytes were present in culture after 7 days. The cell numbers recovered from defined stages by DNA flow cytometry were close to those found in morphometric studies. Flow cytometry is an efficient quantitation method for cells liberated from seminiferous epithelium. Spermatogonia, spermatocytes, and early spermatids are able to differentiate in vitro, but spermatids approaching the elongation (acrosome) phase, and particularly the maturation phase, fail to differentiate under present culture conditions.

Acid Phosphatase↗
PubMed2001

Pharmacological characteristics of solid-phase von Willebrand factor in human platelets.

1. The pharmacological characteristics of solid-phase von Willebrand factor (svWF), a novel platelet agonist, were studied. 2. Washed platelet suspensions were obtained from human blood and the effects of svWF on platelets were measured using aggregometry, phase-contrast microscopy, flow cytometry and zymography. 3. Incubation of platelets with svWF (0.2 - 1.2 microg ml(-1)) resulted in their adhesion to the ligand, while co-incubations of svWF with subthreshold concentrations of ADP, collagen and thrombin resulted in aggregation. 4. 6B4 inhibitory anti-glycoprotein (GP)Ib antibodies abolished platelet adhesion stimulated by svWF, while aggregation was reduced in the presence of 6B4 and N-Acetyl-Pen-Arg-Gly-Asp-Cys, an antagonist of GPIIb/IIIa. 5. Platelet adhesion stimulated with svWF was associated with a concentration-dependent increase in expression of GPIb, but not of GPIIb/IIIa. 6. In contrast, collagen (0.5 - 10.0 microg ml(-1)) caused down-regulation of GPIb and up-regulation of GPIIb/IIIa in platelets. 7. Solid-phase vWF (1.2 microg ml(-1)) resulted in the release of MMP-2 from platelets. 8. Inhibition of MMP-2 with phenanthroline (10 microM), but not with aspirin or apyrase, inhibited platelet adhesion stimulated with svWF. 9. In contrast, human recombinant MMP-2 potentiated both the effects of svWF on adhesion and up-regulation of GPIb. 10. Platelet adhesion and aggregation stimulated with svWF were reduced by S-nitroso-n-acetyl-penicillamine, an NO donor, and prostacyclin. 11. Thus, stimulation of human platelets with svWF leads to adhesion and aggregation that are mediated via activation of GPIb and GPIIb/IIIa, respectively. 12. Mechanisms of activation of GPIb by svWF involve the release of MMP-2, and are regulated by NO and prostacyclin.

Biological Transport↗
PubMed2004

The influence of humidity on the aerosolisation of micronised and SEDS produced salbutamol sulphate.

The influence of storage humidity on the aerosolisation efficiency of micronised and supercritical fluid salbutamol sulphate formulations (containing a lactose carrier) were investigated using the twin stage impinger (TSI). Storage humidity had a significant effect on the aerosolisation efficiency of both micronised and solution enhanced dispersion by supercritical fluids (SEDS) salbutamol sulphate (ANOVA P <0.05), suggesting capillary interactions to be an important factor when considering formulation performance. Furthermore, significant differences between the aerosolisation performance of micronised and SEDS salbutamol sulphate were observed at elevated humidities (>63% RH) (Fishers pairwise P <0.05). It is suggested that such variations may be due to differences in physical stability of the micronised and SEDS produced material. Dynamic vapor sorption, and atomic force microscopy (AFM) phase imaging suggested the micronised material to contain amorphous content that was most likely present on the micronised particulate surfaces. Thus, at high humidity, surface amorphous regions may have the ability to re-crystallize and effectively 'fuse' to the lactose carrier surface. This would potentially reduce the ability for the micronised material to be aerosolized and thus result in a greater decrease in FPF when compared to SEDS produced material at equivalent RH.

Aerosols↗
PubMed2001

Excessive base excision repair of 5-hydroxymethyluracil from DNA induces apoptosis in Chinese hamster V79 cells containing mutant p53.

We have demonstrated previously that the toxicity of 5-hydroxymethyl-2'-deoxyuridine (hmdUrd) to Chinese hamster fibroblasts (V79 cells) results from enzymatic removal of large numbers of hydroxymethyluracil residues from the DNA backbone [Boorstein,R. et al. (1992) Mol. Cell. Biol., 12, 5536-5540]. Here we report that a significant portion of the hmdUrd-induced cell death that is dependent on DNA base excision repair in V79 cells is apoptosis. Incubation of V79 cells with pharmacologically relevant concentrations of hmdUrd resulted in the characteristic changes of apoptosis as measured by gel electrophoresis, flow cytometry and phase contrast microscopy. However, hmdUrd did not induce apoptosis in V79mut1 cells, which are deficient in DNA base excision repair of 5-hydroxymethyluracil (hmUra). Apoptosis was not prevented by addition of 3-aminobenzamide, which inhibits synthesis of poly(ADP-ribose) from NAD, indicating that apoptosis was not the direct consequence of NAD depletion. Pulsed field gel electrophoresis indicated that hmdUrd treatment resulted in high molecular weight (2.2-4.5 Mb) DNA double-strand breaks prior to formation of internucleosomal ladders in V79 cells. Simultaneous measurement of DNA strand breaks with bromodeoxyuridine/terminal deoxynucleotidyl transferase-fluorescein isothiocyanate labeling and of cell cycle distribution indicated that cells with DNA strand breaks accumulated in late S/G(2) and that hmdUrd-treated cells underwent apoptosis after arrest in late S/G(2) phase. Our results indicate that excessive DNA base excision repair results in the generation of high molecular weight DNA double-strand breaks and eventually leads to apoptosis in V79 cells. Thus, delayed apoptosis following DNA damage can be a consequence of excessive DNA repair activity. Immunochemical analysis showed that both V79 and V79mut1 cells contained mutant p53, indicating that apoptosis induced by DNA base excision repair can be independent of p53.

Animals↗
PubMed2006

A study on medium chain length-polyhydroxyalkanoate accumulation in Escherichia coli harbouring phaC1 gene of indigenous Pseudomonas sp. LDC-5.

AIMS: This study is mainly focused on the heterologous expression and accumulation of polyhydroxyalkanoates (PHA) in Escherichia coli. METHODS AND RESULTS: PHA synthase gene (phaC1) from indigenous Pseudomonas sp. LDC-5 was amplified by PCR and cloned in E. coli (Qiagen EZ competent cells). The recombinant E. coli was analysed and confirmed for its expression of phaC1 gene by phase contrast microscopy, Western blot analysis and spectral studies (Fourier-transform infrared spectroscopy). It was further evaluated for its accumulation in different carbon and nitrogen sources. The accumulation of PHA (3.4 g l(-1)) was enhanced in the medium supplemented with glycerol and fish peptone compared to the other carbon and nitrogen sources used in this study. CONCLUSIONS: This study would enable the reduction of cost of PHA production. SIGNIFICANCE AND IMPACT OF THE STUDY: An important part of this study is that E. coli harbouring partial phaC1 gene could accumulate medium chain length PHA significantly. The results demonstrated that the E. coli strain could be a potential candidate for the large-scale production of polymer. The conditions for the higher yield and productivity will be optimized in the next phase using fermentation studies.

Acyltransferases↗
PubMed2004

Human corneal endothelial cell proliferation: potential for use in regenerative medicine.

PURPOSE: To review and update the experience of our laboratory in culturing human corneal endothelial cells (HCEC) from young and older donors. METHODS: Corneas were obtained from National Disease Research Interchange, Philadelphia, PA. Data from the past 3 years were reviewed to develop criteria for selecting donor corneas to be used for endothelial cell culture. Immunocytochemical localization using mAb 9.3.E identified endothelial cells, and Ki67 staining demonstrated actively cycling cells. Cell counts demonstrated the effect of growth-promoting agents on proliferation of cells from young (<30 years old) and older (>50 years old) donors. Phase-contrast microscopy documented morphologic characteristics of cells in primary culture and the effect of growth factors on cell morphology. RESULTS: Exclusion criteria were developed to increase the chance of successful culture of HCEC. Isolation methods to remove Descemet membrane with attached endothelial cells avoided contamination with other corneal cell types. EDTA treatment combined with mechanical disruption facilitated isolation of cells. Culture medium containing FBS, EGF, NGF, and bovine pituitary extract stimulated maximal growth and facilitated normal monolayer formation. Age-related differences were detected in the density of confluent cells in primary culture and in the proliferative response to growth-promoting agents. CONCLUSIONS: Untransformed HCEC can be successfully cultured from the corneas of both young and older donors by using care in the selection of donor material. Care must also be taken in the early phases of endothelial cell isolation to obtain maximal numbers of healthy cells for culture. There appear to be true age-related differences in overall proliferative capacity; however, the relative response to specific growth factors was similar in cells from young and older donors. Results of these studies provide guidelines for successful growth of untransformed HCEC for use in regenerative medicine.

Adolescent↗
PubMed1975

Inhibition of formation of microtubular paracrystals in HeLa-S3 cells by neocarzinostatin.

The effect of an antitumor antibiotic, neocarzinostatin (NCS), on the formation of microtubular paracrystals (PC) induced by vinblastine sulfate, 10 mug/ml, in HeLa-S3 cells was examined by phase-contrast microscopy. The pretreatment of HeLa-S3 cells with NCS, 5 to 50 mug/ml, for 4 hr prevented the PC formation, and there was a dose response of NCS to the degree of inhibition. When the same inhibitory effect on PC formation was examined with other antitumor agents at high doses (50 mug/ml), colchicine was found to be one of the most effective agents, like NCS. Puromycin, antimycin, adriamycin, cytochalasin B, and cycloheximide revealed moderate activity, and the other antibiotics, such as mitomycin C, bleomycin, and rifampicin, did not show any effect at all. NCS was a unique antibiotic that inhibited PC formation among inhibitors of DNA synthesis. It was suggested that NCS affects the microfibrillar-microtubular proteins system in vivo, resulting in the inhibitions of organization of spindle fibers from microtubules at the G2 phase in HeLa cells.

Anti-Bacterial Agents↗
PubMed2006

Residue formations of phosphorus hydride polymers and phosphorus oxyacids during phosphine gas fumigations of stored products.

With the extent of international usage and the critical role phosphine gas (PH3) plays in commercial pest control, identification of the residual components deposited during fumigation is mandatory. It has been postulated that these infrequent residues are primarily composed of phosphoric acid or reduced forms of phosphoric acid [hypophosphorous acid (H3PO2) and phosphorous acid (H3PO3)], due to the oxidative degradation of phosphine. Using environmental scanning electron microscopy, gas phase Fourier transform infrared spectroscopy, and X-ray fluorescence spectroscopy, the structural elucidation and formation mechanism of the yellow amorphous polyhydric phosphorus polymers (P(x)H(y)) that occur in addition to the lower oxyacids of phosphorus in residues deposited during PH3 fumigations of select tobacco commodities are explored. This research determined that nitric oxide gas (or nitrogen dioxide) initiates residue formation of phosphorus hydride polymers and phosphorus oxyacids during PH3 fumigations of stored products.

Drug Residues↗
PubMed1994

Staurosporine induces the outgrowth of neurites from the dorsal root ganglion of the chick embryo and PC12D cells.

Staurosporine, a potent inhibitor of protein kinases, caused the rapid outgrowth of neurites from cultured dorsal root ganglia of chick embryos and from PC12D cells, a subline of PC12 cells. Treatment of dorsal root ganglia with 1 to 20 nM staurosporine resulted in the extensive outgrowth of neurites that were indistinguishable from those induced by NGF, as assessed by phase-contrast microscopy, electron microscopy and cytochemical staining of actin and tubulin. However, neurites generated from the ganglia in response to the higher concentrations of staurosporine (40-100 nM) seemed to have different characteristics, possibly as a result of the inhibition of cell migration from ganglia. The sequential changes in morphology of PC12D cells in response to staurosporine and to NGF were revealed by staining of actin. Ruffling membranes emerged at the margins of PC12D cells within 4 min after the addition of staurosporine or of NGF. From 10 min to 24 h after the addition of either compound, the ruffles were transformed into several projections that became growing neurites. The formation of ruffles and the outgrowth of neurites were both apparent at a concentration of staurosporine of 10 nM. The neurites that emerged from PC12D cells in response to staurosporine and in response to NGF were indistinguishable under the phase-contrast microscope and after staining of actin and tubulin. However, staurosporine never promoted survival of PC12D cells in serum-free conditions as that promoted by NGF. The observations indicate that staurosporine at nanomolar concentrations may reproduce the neurogenic changes that induced by NGF in primed neuronal cells, although it can not mimic the action of NGF that supports survival of neurons.

Alkaloids↗
PubMed1982

The synthesis of elastin, collagen, and glycosaminoglycans by high density primary cultures of neonatal rat aortic smooth muscle. An ultrastructural and biochemical study.

Primary cultures of neonatal rat aortic smooth muscle cells inoculated at high densities (1 X 10(6) cells/25 cm2 Falcon flask) with adequate nutrient media and pH control grow rapidly and form multilayers of cells with typical "hill and valley" organization. After 10 days growth insoluble elastin formation could be visualized by phase contrast microscopy as small particles which grew rapidly to become larger irregular refractile aggregates and later coalesced to form larger aggregates and small fibres. With light and electronmicroscopy, elastin was the predominant matrix protein formed, with the "hill regions" of cultures containing abundant elastin aggregates and some collagen. In 2-week-old cultures differentiation could be observed within the cell multilayer. The older deeper cells contained more protein synthesis organelles and myofilaments and were in close association with large often coalescing elastin aggregates; compared to younger more superficial cells which contained more free polyribosomes less myofilaments, and were associated with fewer and small elastin aggregates. In older cultures this differentiation was not apparent; the cells contained many myofilaments, dense bodies, and lysosomes. Elastin aggregates and newly formed elastic fibres were abundant in the matrix. Quantitative analysis of insoluble elastin formation in the cell layer during the 4-week culture period indicated continuous biosynthesis and deposition which paralleled that of desmosine formation. Amino-acid analysis of a hot alkali insoluble residue (regarded as elastin) from 30-day-old cultures gave a profile identical with neonatal rat aortic elastin in vivo. Insoluble collagen formation in the cell layer tended to plateau after the log phase of growth was completed (10 days). Proteoglycans were found predominantly in the supernatant media. Glycosaminoglycan analysis revealed a profile of dermatan sulphate (32%), chondroitin 4-sulphate (43%), keratan and heparan sulphate (30%), with only a trace of hyaluronic acid. This study indicates that primary cultures of neonatal rat aortic smooth muscle cells remain differentiated in culture and have the unique capacity to continue to synthesize and deposit large amounts (mg) of insoluble elastin which aggregate and from elastic fibres in vitro.

Animals↗
PubMed1984

Human autoantibodies against desmosomes: possible causative factors in pemphigus.

Pemphigus is a human disease that causes extensive blistering of the skin. This blistering is related to a loss of epidermal cell cohesion and is accompanied by circulating autoantibodies that stain epidermal cell surfaces, as shown by immunofluorescence microscopy. One of the major components involved in epidermal cell cohesion is the desmosome. The pathological changes that accompany pemphigus led us to determine whether the autoantibodies are specific for desmosomes. Incubation of cultured mouse keratinocytes in medium containing pemphigus antiserum leads to cell separation at cell-cell contact sites, which possess desmosomes. Tissue sections of mouse skin processed for indirect immunofluorescence, using pemphigus antiserum or a rabbit antiserum directed against components of desmosomes, show similar punctate cell-surface staining patterns within the epidermis. Cultured mouse keratinocytes possessing well-defined intermediate filament bundles (tonofilaments) and desmosomes were processed for double indirect immunofluorescence, using a monoclonal antibody directed against mouse skin keratin and either pemphigus antiserum or the desmosome antiserum. The keratinocytes exhibit a complex system of keratin-containing tonofilaments. Tonofilaments in contacting cells are separated by thin dark bands at the cell surface, which correspond precisely to desmosomal plaques seen by phase-contrast microscopy. These bands specifically stain with both pemphigus antiserum and the desmosome antiserum. Double indirect immunofluorescence of the cultured mouse keratinocytes, using pemphigus antiserum and the desmosome antiserum, reveals that the pemphigus autoantibodies stain the same areas of cell-cell contact as the desmosome antibodies. Our evidence supports the idea that pemphigus blisters form, at least in part, from a specific antibody-induced disruption of desmosomes in the epidermis.

Animals↗
PubMed1997

Expression of extracellular matrix proteins in human periodontal ligament cells during mineralization in vitro.

Periodontal regeneration is a complex process that requires coordinated responses from several cell types within the periodontium. It is generally accepted that the periodontal ligament (PDL) has a heterogeneous cell population, where some of the cells may be capable of differentiating into either cementoblasts or osteoblasts. Thus, it has been hypothesized that PDL cells play a role in promoting periodontal regeneration. However, definitive evidence to support this concept is lacking. Previously, we reported that PDL cells induce biomineralization as determined by Von Kossa histochemistry and transmission electron microscopy. To further determine the osteoblast-like properties of PDL cells, human PDL cells were exposed to dexamethasone (DEX) in order to promote an osteoblast phenotype, and then cell activity monitored during mineral nodule formation in vitro. For mineralization studies, cells were cultured in DMEM containing 10% FBS and a) vehicle only; b) ascorbic acid (50 micrograms/ml) and beta-glycerophosphate (10 mM); or c) ascorbic acid, beta-glycerophosphate and DEX (100 nM) for 30 days. In addition, the effects of DEX on PDL cells in non-mineralizing media were determined. Cells were stained weekly to evaluate mineral-like nodules, using the Von Kossa method. Northern blot analyses for mRNA steady state levels for several bone-associated proteins, i.e., osteopontin (OPN), bone sialoprotein (BSP), alkaline phosphatase (ALP), osteocalcin (OCN), alpha 2(1)(type 1) collagen and osteonectin (ON), were performed. DNA levels were also determined during the 30-day mineralization period. Under phase contrast microscopy, PDL cells in non-mineralizing media treated with DEX exhibited a more spindle-shaped morphology when compared with similar cells not exposed to DEX. Mineralizing conditions were required to induce mineral nodule formation. However, in this situation, mineral induction was independent of DEX; and furthermore, DEX-treated cells did not exhibit a different morphological pattern when compared with non-DEX treated cells. Mineral-like nodules were first seen at day 15, in concert with an increase followed by a decrease in expression of type I collagen and ON mRNA in both DEX-treated and non-treated cultures. Using Northern blot analysis for detection of specific proteins, we found that PDL cells did not express OPN, BSP, OCN, or ALP under any of the conditions used in this study. DEX did not alter DNA content in the cultures during the mineralization period. These results confirm that human periodontal ligament cells can be induced to mineralize in vitro and indicate that dexamethasone does not significantly alter the extent and pattern of mineralization.

Alkaline Phosphatase↗
PubMed2004

[Surface architectonics and cytoskeleton of erythrocytes and their modulation by adrenergic agents in patients with bronchial asthma].

AIM: To evaluate erythrocyte surface architectonics and cytoskeleton in bronchial asthma (BA) under modulation of adrenergic agents. MATERIAL AND METHODS: 24 healthy persons, 61 patients with bronchial asthma (BA) were examined. Of them, 28 patients had allergic BA (ABA) and 33 ones had nonallergic BA (NABA). Erythrocyte surface architectonics was studied by phase-contrast microscopy. Fixation in 0.5% solution of glutar aldehyde was used, preparation "squashed drop" was prepared. In all preparations adrenalin hydrochloride and obzidan were used in equimolar final concentrations of 4.10(-5) M. The mean morphologic index of transformation that reflects the shift to stomatocytosis or to echinocytosis was estimated to characterize integrally erythrocyte surface architectonics. The cytoskeleton was studied by the modified method of Chentosov's et al. The integral optic density was evaluated on imaging analyzer of Ista-Videotest company (St-Petersburg). RESULTS: In healthy persons there was a correlation between erythrocyte surface architectonics and cytoskeleton under modulation of adrenergic system. Adrenalin-induced decrease of cytoskeletal proteins correlated with the shift to stomatocytosis. In NABA erythrocyte surface architectonics was characterized by a pronounced shift to stomatocytosis. This shift was accompanied with the most pronounced decrease of cytoskeletal proteins and it reduced in remission. In ABA manifestation of the shift was minimal and did not depend on the phase of the disease. In ABA no changes in erythrocyte surface architectonics in the presence of adrenalin were revealed. In the same conditions a decrease in cytoskeletal proteins was found. CONCLUSION: A correlation was found between erythrocyte surface architectonics and cytoskeleton in healthy persons. In ABA, under modulation of adrenergic system by adrenalin dissociation was revealed between receptor and cytoskeletal mechanisms of cell form induction. This dissociation does not depend on the phase of the disease and is thought to be one of the important postreceptor disorders typical for this variant of the disease.

Adrenergic beta-Antagonists↗
PubMed1990

Scanning tunneling microscopy of a liquid crystalline phase of poly((dA-dT).(dA-dT)) induced by a histone H1 peptide.

In this report, we present the first observations of uncoated poly((dA-dT).(dA-dT)) molecules organized in a liquid crystalline phase induced by the binding of a histone H1 peptide. The effect of the peptide on the polymer condensation is clearly illustrated on the large-scale STM images which reveal a well defined spacing between parallel DNA helices. High resolution images of rare isolated molecules of poly((dA-dT).(dA-dT)) exhibit two sets of helical pitch values, 6 and 7.5 nm. While the lower value can be correlated with the pitch of poly((dA-dT).(dA-dT)), the larger one may arise from peptide binding in the polymer minor groove.

Crystallization↗