Ultrastructure of neurons manifested by hyperchromia and vacuolization observed in nerve tissue following hypoxia

100 days after the exposure of the rat sensorimotor cortex to hypoxic hypoxia two types of hyperchromic neurons with vacuolization of the cytoplasm were described. Using electron cytochemical method for the differential staining of ribonucleoproteins, it has been shown that the first type of hyperchromic neurons were cells with irreversible dystrophic changes and the second type were cells without irreversible dystrophy but with changes in the DNA-RNA-protein synthesizing system.     

Electron-cytochemical study of the changes in the structure of hyperchromic neurons shown after chlorpromazine administration

By means of Bernhard's electron cytochemical method for revealing DNP and RNP, the hyperchromic neurons in the cerebral cortex have been investigated 3, 6, 24 and 48 hours after chlorpromazine hydrochloride administration (15 mg/kg). Development of hyperchromia in the neurons has been followed beginning from minimal changes in the nucleus and cytoplasm up to their maximal reconstruction and a subsequent restoration to the normal stage. The data obtained demonstrate that hyperchromia of the neuron during various phases of its development can be characterized both by a decreasing synthetic activity and by restorative processes during the last period when the functional state is normalized.     

Status of the DNA-RNA-protein synthesizing system in neurons of the sensomotor cortex of the brain of the 30-day-old rat

By means of the electron cytochemical method ribonucleoprotein (RNP) particles, condensed chromatin (CCh) and ribosomes of cytoplasm are describe in normo- and hyperchromic neurons (HChN) of the V and VI layers of the sensomotor cortex. The normochromic neurons are characterized by nearly a complete absence of CCh, a great number of fibrillar RNP particles. The ribosomes of cytoplasma are organized as polysomes. This demonstrates a high metabolic activity of the DNA-RNA-protein system in these cells. In nuclei of one HChN group numerous small CCh clumps are revealed, amount of RNP particles does not change noticeably, comparing the nuclei of the normochromic cells. In cytoplasm a partial dissociation of polysomes takes place. All this demonstrates a decreased RNA synthesis in the nucleus and protein in cytoplasm of the given cells. In another HChN group the nucleus is filled with large CCh clumps. The number of fibrillar RNP particles decreases noticeably, and the number of granular ones increases. A complete dissociation of polysomes occurs. This demonstrates that in the cells mentioned not only RNA and protein synthesis is decreased, but the processing and nucleo-cytoplasmic transport of RNA is disturbed. The presence of transitional forms between the neuronal forms described makes it possible to suppose certain cyclicity in the work of their plastic apparatus, the normo- and hyperchromic neurons being morphologic equivalents of certain phases of the cycle.     

Method of quantitative assessment of morphological changes in the central nervous system]

The author present a variant of quantitative assessment of the degree of morphological changes in the central nervous system neurons. It is suggested that the following groups of the changed neurons should be distinguished: swollen neuron with the initial manifestations of breaking large tigroid lumps into smaller ones; swollen neuron with marked phenomena of breaking large tigroid lumps into smaller ones and initial phenomena of hypochromatosis; swollen neuron with total tigrolysis with hyper- and hypochromatosis; dehydrated hyperchromic neuron; vacuolized neuron; contracted atrophic neuron; perished neuron. Each of the mentioned groups is given a mark, characterizing the degree of morphological changes. A formula for the assessment of the degree of morphological changes for individual formations and zones of the central nervous system is suggested.     

The substance with competence inducing activity interacts with DNA and produces a hyperchromic increase of optical density

The active substance inducing competence in non-competent cells ofDiplococcus pneumoniae was isolated by ammonium sulphate precipitation from the sterile filtrate of a culture 40–60 min after the peak of competence had passed. After being dialyzed and dried from the frozen state the substance was further purified by chromatography on Sephadex G100 or DEAE cellulose column. In all cases the fractions containing the competence inducing activity contained also the transforming DNA-inactivating activity. A hyperchromic increase of optical density was found on incubating the active substance with various DNAs and RNAs as substrates. The hyperchromic increment is different from that of pancreatic endo-nuclease I and phosphodiesterase.     

Formation of structural and ultrastructural organization of striatum rat postnatal ontogenesis upon changes in their embryonal development

By light microscopy (by Nissl and Golgi), electron microscopy, and immunohistochemistry methods, formation of structure of the brain striatum dorsolateral part from birth to the 3-month age was studied in rats submitted to acute hypoxia at the period of embryogenesis. It has been established that hypoxia at the 13.5th day (E13.5) leads to a delay of neuronogenesis for the first two weeks of postnatal development as compared with control animals, while the majority of large neurons at this period are degenerated by the type of chromatolysis with swelling cell body and processes and lysis of cytoplasmic organoids. By the end of the 3rd week, shrunk hyperchromic or picnomorphic neurons with the electron-dense cytoplasm and enlarged tubules of endoplasmic reticulum and Golgi complex were also observed. An increased number of swollen processes of glial cells was detected in neuropil around degenerating neurons. By the 30th day as well as in adult rats there was observed destruction of mitochondrial apparatus, an increase of the number of lysosomes, and the appearance of bladed nuclei - signs of apoptotic cell death, which was also confirmed by an increased expression of proapoptotic p53 protein and its colocalization with caspase-3 in a part of neurons. Morphometrical analysis has shown a decrease of density of striatum cell arrangement and a change of ratio of different cell types in the rats submitted to hypoxia as compared with control group. At early stages of postnatal ontogenesis there was the greatest decrease (42.3% at the 5th day, 14.2% at the 10th day, p < 0.01) of the number of large neurons with the area more than 80 microm2. After 3 weeks of postnatal development the number of middlesize neurons (30-95 microm2) decreased (by 11.8-19.2%) as compared with control. The obtained data show that a change of conditions of embryogenesis (hypoxia) at the period of the most intensive proliferation of the forebrain neuroblasts leads to disturbances of the process of formation of the striatum nervous tissue. This can be the cause of delay of development and disturbances of behavior and learning observed in rats submitted to prenatal hypoxia.     

Formation of striatum structural and ultrastructural organization in rat postnatal ontogenesis at changes of conditions of their embryonic development

Using light microscopy (Nissl and Golgi techniques), electron microscopy and immunohistochemistry, formation of structure of the brain striatum dorsolateral part from birth to three month of age was studied in rats submitted to acute hypoxia at the period of embryogenesis. Hypoxia at the 13.5th day of pregnancy (E 13.5) was found to lead to a delay of neuronogenesis for the first two weeks of postnatal development as compared with control animals, and the majority of large neurons for this period were degenerated by the type of chromatolysis with swelling of the cell body and processes and lysis of cytoplasmic organelles. By the end of the third week, shrunken hyperchromic or pycnomorphic neurons with the electron-dense cytoplasm and enlarged tubules of endoplasmic reticulum and Golgi complex were also observed. An increased number of swollen processes of glial cells was found in neuropil around the degenerating neurons. By the 30th day as well as in adult animals, destruction of mitochondrial apparatus, an increased number of lysosomes, and blade-shaped nuclei, which are characteristics of the apoptotic cell death, were observed. This is also confirmed by an increased expression of proapoptotic protein (p53) and its co-localization with caspase-3 in a part of neurons. Morphometric analysis showed a decrease of the cell distribution density in striatum and a change of ratio of different cell types in hypoxia-exposed rats as compared with control group. The most pronounced decrease (42.3% at the 5th day, 14.2% at the 10th day, p < 0.01) of the number of large neurons (larger than 80 μm²) was revealed at early stages of postnatal ontogenesis. After 3 postnatal weeks, the number of middle-sized neurons (30–95 μm²) decreased (by 11.8–19.2% as compared with control, p < 0.05). The obtained data have shown that changes of embryogenesis conditions (hypoxia) at the period of the most intensive proliferation of telencephalon neuroblasts lead to impairment of the process of striatal nervous tissue formation. This might be the cause of delay of development and disturbances of behavior and learning, which are observed in rats exposed to prenatal hypoxia.     

Raman studies of the helix-to-coil transition in poly-L-glutamic acid and poly-L-ornithine

The conformational transitions in water and in the solid state of poly-L -glutamic acid (PGA) and poly-L -ornithine (PO) have been studied by Raman spectroscopy. The Raman spectra of PGA, PO, and the monomer, dimer, and trimer of PGA in aqueous solutions and solid state are presented. The Raman spectral changes of PGA and PO were followed through the helix-to-coil transition induced by p^H, temperature, and solvent composition. A hyperchromic shift in the intensity of the amide III line accompanying the helix-to-coil transition was observed. This hyperchromic intensity shift occurs abruptly as a function of p^H but more slowly with heat denaturation of the alpha helix indicating that the Raman spectrum is sensitive to the transition mechanism. The high-temperature coil and the charged coil may have different conformations as evidenced by different amide III frequencies but similar intensities in these two conformations.     

Use of critical point polyacrylamide sols in thermal denaturation experiments with chromatin at physiological ionic strength

Low percentage highly crosslinked polyacrylamide gels just above the critical point in the chemically polymerized sol to gel transition are used to generate polyacrylamide sols at critical point concentrations, 7.4 g liter-1, by mild heating. We find that chromatin samples mixed with these sols induce the sol to gel transition in a process of complex coacervation. In this state, salt insoluble chicken erythrocyte chromatin is stabilized against large scale aggregation and precipitation during thermal denaturation at physiological sodium ion concentrations. The hyperchromic melting behavior of DNA in polyacrylamide sols is reproducible and consistent throughout a wide range of sodium chloride concentrations. Empirical spectroscopic techniques are discussed which isolate temperature-dependent hyperchromic signals at 260 nm due to conformational changes of DNA in chromatin and local environmental changes which promote anomalous light scattering.     

The use of counter-current distribution to examine the effect of damaging agents on DNA

Mammalian DNA's were separated using a counter-current distribution system for demonstrating alteration in secondary structure after heat denaturation and drug treatment. By using this method a complete separation of native and denatured DNA was achieved. Although the separation of DNA depends on the temperature used for denaturation, the counter-current distribution pattern did not follow exactly the hyperchromic shift. The results suggest that counter-current distribution offers a complementary approach for the study of DNA secondary structure as this method reveals alterations occurring over a wider temperature range than the increase in ultraviolet absorption. The changes in distribution pattern demonstrate cross-linkage occurring with nitrogen mustard and single-strand breaks following methylene dimethanesulphonate (MDMS) treatment in vitro.     

A prospective controlled assessment of microdermabrasion for damaged skin and fine rhytides

Aged skin is characterized by rhytides but also by epidermal and dermal atrophy, rough skin texture, irregular pigmentation, telangiectasias, and laxity. Microdermabrasion is an office-based mechanical resurfacing technique alternative to traditional dermabrasion. It has been used in Europe since 1992 with great acceptance. The purpose of this study was to evaluate and quantify the degree of visible improvement in photodamaged skin and fine rhytides following a series of microdermabrasion treatments. A single operator treated 20 patients with varying degrees of photodamage and rhytides with a series of eight microdermabrasion treatments at 1-week intervals; 17 subjects completed the entire study protocol. Standardized photographic documentation was performed before and after each treatment, and a survey questionnaire was completed by each subject. Punch biopsy specimens (3 mm) were collected on treated and matched nontreated control sites and evaluated for histological characteristics. Preprocedure and postprocedure photographs were rated on a 5-point scale by independent blinded observers. A total of 30 blinded observers (16 plastic surgeons and 14 laypersons) rated all photographs. The results showed that all observers rated a significant improvement of hyperchromic discoloration (p = 0.004), while only nonmedical observers observed improvement in fine rhytides. All patients were very satisfied with the results. Common side effects were mild to moderate discomfort occurring on bony areas during the treatment and an itching and tingling sensation for 2 days after treatment. No infections or scars were observed postoperatively. The average epidermal thickness in the untreated samples was 103 +/- 23 microM (mean +/- SD) before treatment compared with 148 +/- 41 microM after treatment (p < 0.001). Histologic analysis of the matched punch biopsy specimens showed an increase in organized collagen in treated versus nontreated sites. Treatment of aged skin using a series of microdermabrasion treatments is an effective, noninvasive method of skin rejuvenation with minimal risk and patient downtime. It is safe and improves skin quality by minimizing certain hyperchromic pigmentations.     

Interaction of gene 5 protein with DNA

Gene 5 protein bound to both linear and circular single-stranded DNA and saturated the DNA at a protein-to-DNA weight ratio of 7–8. The viscosity of a complex of the protein with single-stranded DNA was initially less than that of the DNA and slowly increased with time suggesting that the complex adopts its final hydrodynamic shape very slowly. This shape change was confirmed by gradient centrifugation. The complex has a more extended structure than DNA alone accounting for its high viscosity and low S value. Gene 5 protein also bound to linear double-stranded DNA though not as strongly as to single-stranded DNA. The protein decreased the transition temperature, T_m, for viscosity loss of double-stranded DNA by 20 °C in 1 and 10 mm salt at a protein-to-DNA ratio of 2.2. At these low ratios there was no decrease in the hyperchromic T_m at 260 nm. At higher ratios of protein to DNA, the hyperchromic T_m was decreased to a constant value and not by a constant amount. Under no conditions was gene 5 protein able to completely separate the complementary strands of double-stranded DNA or to renature denatured DNA.     

The spectral properties and photosensitivities of analogue photopigments regenerated with 10- and 14-substituted retinal analogues

Analogues of 11-cis- and 9-cis-retinal with substitutions at positions 10 and 14 were used to regenerate analogue photopigments with two opsins: that of the transmuted (cone-like) 521-pigment of Gekko gekko and that of the rhodopsin of Porichthys notatus. The spectral absorbances and photosensitivities of the regenerated photopigments were determined and compared, first, between the two systems of analogue photopigments, and second, in the responses to the two opsins. Unlike the 10-fluoropigments, the comparable 14-compounds were significantly red-shifted by 19-30 nm and their sensitivity to light was similar to that of the parent 11-cis- and 9-cis-pigments. These were the results for both analogue pigments. In contrast, the 10-pigments were spectrally located close to the wavelengths of the parent compounds and the photosensitivity was significantly reduced, especially in the case of the 9-cis-analogues. Evidence was obtained for a steric hindrance effect at position 14, for no regeneration was obtained when methyl or ethyl groups were at this carbon. In the 10-substituted retinals, steric hindrance was noted only for the gecko; only the fluorosubstituted, but not the chloro-, the methyl- or the ethyl-substituted, retinals reacted. With the fish opsin, pigments were regenerated with all but the ethyl-substituted retinal. The gecko opsin appears to have a more restricted binding site. Another feature of the gecko was related to the chloride bathochromic and hyperchromic effects, in which the 521-pigment prepared in a chloride-deficient state has a blue-shifted spectrum compared with the spectrum obtained after the addition of chloride, and its extinction is raised by the addition of chloride to give a mean ratio of 1.23 for the two extinctions, one with, the other without, added chloride. The 11-cis-10-F-analogue pigment gave both chloride effects and the hyperchromic ratio was the same as that recorded for the native visual pigment. In contrast, the pigment formed with 11-cis-14-F-retinal gave a hyperchromic ratio significantly greater than 1.23. A similar contrast in the responses to chloride was obtained with the analogue photopigments regenerated with the 9-cis-10-F- and 9-cis-14-F-chromophores. This difference between the two systems is interpreted as the result of a specific configurational feature of the gecko opsin when in the chloride-deficient state that is relevant to the binding of the retinal analogue.(ABSTRACT TRUNCATED AT 400 WORDS)     

Interpretation of hypochromic and hyperchromic intensity changes in the Raman spectra of polypeptides and polynucleotides undergoing transition.

The hyperchromic and hypochromic changes in the intensity of the amide-I and amide-III lines of polypeptides and certain ring vibrations of the bases of polynucleotides are shown to be related to similar changes in the lower energy uv absorption bands. The selection rules strictly limit the pairs of excited electronic states that can contribute to the elements of the polarizability matrix. An energy-dependent term in this equation weights the contribution of the pairs of electronic transitions in favor of those involving the lower energy transitions. For both polypeptides and polynucleotides, there is a large hypochromic inensity change in the first π → π* exciton band upon the coil-to-helix transition. Through the selection rules, certain conformationally sensitive Raman lines are shown to derive their intensity predominantly from this band and hence also display hypochromism. Again, through an application of the selection rules, certain Raman lines can be demonstrated to depend predominantly for their intensity upon the n → π* transition, and consequently have the opposite hyperchromic intensity change upon the same conformational transition.     

Mescaline-induced changes of brain-cortex ribosomes. Effect of mescaline on the hydrogen-bonded structure of ribonucleic acid of brain-cortex ribosomes

1. The action of mescaline sulphate on the hydrogen-bonded structure of the RNA constituent of ribosomes of goat brain-cortex slices was studied by using the hyperchromic effect of heating and formaldehyde reaction. 2. The ribosomal total RNA species of the mescaline-treated brain-cortex slices have a smaller proportion of hydrogen-bonded structure than the ribosomal RNA species of the untreated brain-cortex slices. 3. Mescaline also appears to have affected this lowering of hydrogen-bonded structure of the ribosomal 28S RNA of brain-cortex tissue.     

一株铁皮石斛内生真菌的色素稳定性研究

本研究以铁皮石斛体内分离筛选得到一株产橙红色色素的内生真菌X1为研究对象,为明确该菌株的种属及其所产天然色素的稳定性,采用分子生物学的方法,鉴定该菌株归属于Neurospora sp.一种。该菌株所产橙色素在400 nm波长处有最大吸收峰;从温度、pH、光照、氧化剂与还原剂四个单因子,对该株菌进行色素稳定性研究。结果表明该色素在紫外光下放置6 h橙色素光吸收值增大,说明有增色效应;在pH 2～8,20～100℃下不受太大影响;H_20_2和Na_2SO_3对该色素有较强的破坏力;Fe³⁺、Zn²⁺、Cu²⁺、Ca²⁺和Mn²⁺对该色素具有保色或增色作用;10%NaCl和15%葡萄糖溶液对色素均有增色效应。该研究对内生真菌分离及真菌色素提取工艺具有一定的理论指导意义。     

Organic solvents cause spectral changes and pKa shifts of thermolysin in peptide synthesis in aqueous-organic one-phase reaction system

Thermolysin underwent spectral changes and pKa shifts upon mixing with alcoholic solvents. A hyperchromic spectra and shift occured upon activation of the enzyme by solvents used in dipeptide (Z-Phe-Phe-OMe) synthesis. This effect was decreased when enzyme was pre-treated with inhibitor. Model substrates did not undergo any significant change on mixing with the same solvents. pKa shift of upto 0.3 units was observed at solvent concentration showing maximum activity and the pKa shifts directly correlated with activity profiles of thermolysin.     

Thermal denaturation of distamycin a - DNA Complexes as followed by hyperchromic spectra

Interaction of distamycin A with calf spleen DNA is investigated by the method of hyperchromic spectra. Hyperchromic spectra of complexes are partitioned into the components corresponding to the denaturation A-T and G+C base pairs and dissociation of the ligand, fractions of respective components are found as a function of temperature. A scheme of melting of successive regions of DNA -with different G+C content together with the scheme of distamycin A redistribution in the course of thermal denaturation is presented.     

Experimental influenza caused by an incomplete form of the agent]

Incomplete form of the influenza virus obtained in accordance with Nayak's method was administered intranasally to mice CBA and C57BL. From the lung tissue of the infected mice the causative agent could be isolated for 45 days, and from the other internal organs--the first hours after the infection only. In morphological investigation of the lungs of animals infected with an incomplete form of the influenza virus a prevalence of the proliferative component against the background of inflammatory changes was noted. Three months after the infection limited lymphoid formations consisting of monomorphic cells with hyperchromic nuclei were defined in the lung tissue. Marked proliferation of the alveolar and bronchial epithelium was observed later; considerable anaplasia of the cells was noted in the papillomatous structure of the alveolar and bronchial epithelium. Glomangioma of the mesentery was observed among affections of other internal organs in 18.7% of mice CBA.     

High mobility group proteins HMG1 and HMG2 do not decrease the melting temperature of DNA

High mobility group proteins 1 and 2 isolated in non-denaturing conditions cannot decrease the temperature of denaturation of DNA. When they are isolated or treated with tricloroacetic acid a hyperchromic peak below the melting temperature of free DNA appears in agreement with previous data ( Javaherian et al. (1979) Nucl . Acids Res. 6, 3569-3580). We show that this is due to light scattering of aggregated protein at submelting temperatures and not to melting of DNA.