[Inhibitory effect of heparin on glomerular mesangial cell]

The pure mesangial cells (MsC) were isolated from the culture of rat glomeruli. After identification, they were divided into heparin-treatment group and control group. It was found that heparin profoundly inhibited the growth of MsC with 75.9% inhibitory rate by means of direct counting MsC. MTT method proved that the inhibitory effect of heparin on MsC was dose-dependent. Electronmicroscopic observation revealed dilated endoplasmic reticulum and Golgi vesicles, more secondary lysosomes, prominent myelin figures and decreased microfilaments in the cytoplasm of the MsC exposed to heparin. Immunocytochemical studies showed that the amounts of FN and LM in the cytoplasm of MsC decreased after heparin treatment. Immunocytochemical investigation also confirmed that heparin could inhibit the expression of nuclear oncogene c-fos and c-jun in the MsC stimulated by PMA. The significance and possible mechanism of inhibitory effect of heparin on MsC were discussed.

tramtrack acts downstream of numb to specify distinct daughter cell fates during asymmetric cell divisions in the Drosophila PNS

Asymmetric cell divisions allow a sensory organ precursor (SOP) cell to generate a neuron and its support cells in the Drosophila PNS. We demonstrate a role of tramtrack (ttk), previously identified as a zinc finger-containing putative transcription factor, in the determination of different daughter cell fates. Both loss of function and overexpression of ttk affect the fates of the SOP progeny. Whereas loss of ttk function transforms support cells to neurons, ttk overexpression results in the reverse transformation. ttk is expressed in support cells but not in neurons. It has been shown that numb, a membrane-associated protein asymmetrically distributed during the SOP division, confers different daughter cell fates. Loss of ttk or numb function results in reciprocal cell fate transformation. Epistatic studies suggest that ttk acts downstream of numb. We propose that ttk executes the command dictated by asymmetrically localized numb to specify distinct daughter cell fates during multiple asymmetric divisions.

Catecholamine-induced mechanical sensitization of cutaneous nociceptors in the rat

C-Fiber mechanoheat (C-MH) nociceptors from the saphenous nerve were studied, in control rats and in rats that underwent surgical sympathectomy. Intradermal injection, alone, of either norepinephrine (NE) or the calcium ionophore, A23187, did not affect mechanical threshold. The combination of A23187 and NE, however, significantly decreased mechanical threshold. In the presence of the alpha 2-adrenergic antagonist, yohimbine, or the cyclooxygenase inhibitor, indomethacin, C-MHs were not sensitized by the combination of NE + A23187. One week after surgical sympathectomy, the number of C-MHs sensitized by NE + A23187 was significantly reduced. In summary, NE appears to sensitize nociceptors indirectly. These data are compatible with the suggestion that a sympathetic postganglionic neuron-dependent release of prostaglandins mediates the sensitization. NE appears to act at an alpha 2-adrenergic receptor, only in the presence of an increased intracellular Ca2+.

Na(+)-K(+)-ATPase activity: role in the impaired sodium excretion of experimental nephrosis in rats

Using the model of adriamycin-induced nephrotic syndrome in rats, we studied the relationship between urine electrolyte excretion rates and proteinuria and determined the activity of Na(+)-K(+)-ATPase in the renal tissue of nephrotic rats. No relationship was found between the increased sodium reabsorption and proteinuria. But the impaired salt excretion was inversely related to the increase of Na(+)-K(+)-ATPase activity in the renal inner medulla. It is proposed that direct effect of adriamycin on renal tubule cells is the primary events, that the increased Na(+)-ATPase activity on basolateral membrane of renal tubule cells be an intrarenal factor which mediates the action of retention of salt by the kidney and that inner medullary collecting ducts might be one of the sites of the sodium retention in nephrotic rats.

RFLP analysis of preferential transmission in interspecific hybrids of Phaseolus vulgaris and P. coccineus

The inheritance of RFLP markers in interspecific hybrids of Phaseolus vulgaris and P. coccineus was analyzed. Of 280 cDNA probes used, 70%-85% revealed polymorphism between species while intraspecific RFLP ranged from 8% to 37%. Segregation of 63 clearly scorable markers was examined in 177 P. vulgaris x P. coccineus F2's maintained as callus. Preferential transmission of the P. vulgaris alleles was observed for 24 of the 28 loci exhibiting non-Mendelian ratios. Although the segregation ratios at 17 loci fit gametic selection, also other factors such as nuclear-cytoplasmic or embryo-endosperm interactions may be involved. In the reciprocal F2, a relatively high frequency of maternal alleles was recovered for several loci, while the paternal allele was favored at others. The cDNA clone detecting the most extreme segregation, with no P. coccineus type detected among 165 P. vulgaris x P. coccineus F2 progeny, showed high homology to histone H2A genes. The markers were mapped to nine linkage groups. Aggregation of markers with preferential maternal transmission was observed, which could be due to selection of individual chromosomes, although false linkage detection cannot be excluded. The results obtained with RFLPs may explain the skewed distribution of phenotypic traits following interspecific hybridization.

Multinuclear and magic-angle spinning NMR investigations of molecular organization in phospholipid-triglyceride aqueous dispersions

The supramolecular organization of multi-bilayers formed by aqueous egg phosphatidylcholine-triolein (PC-TO) mixtures has been investigated using 31P, 13C, and 1H nuclear magnetic resonance (NMR). For these emulsions, which mimic substrates in the early hydrolytic stages of fat digestion, the NMR spectra obtained with magic-angle spinning (MAS) exhibit resolution comparable to that of sonicated vesicles and integrated peak intensities consistent with their chemical composition. Both 31P line shapes and MAS sideband patterns from the phosphocholine group indicate that mixing with triolein produces a PC bilayer which remains predominantly liquid crystalline in its organization; nevertheless, anomalous spectral features in MAS spectra may be attributed to additional phases in which the headgroups adopt a different orientation with respect to the bilayer normal, and tight packing enhances phosphorus-phosphorus interactions. 13C and 1H line widths monitored as a function of PC mole fraction, spinning speed, and decoupling strength show that the choline headgroups and glycerol backbones are anchored preferentially in the phospholipid-triglyceride assemblies, whereas all acyl chains become very fluid. The average degree of chain order also decreases for the mixed dispersions, as judged from spinning-sideband intensities in 1H MAS NMR spectra. The absence of proton spin-diffusion effects in the PC-TO multilayers is demonstrated by examination of their spinning sidebands and relaxation times, making it possible to use MAS-assisted two-dimensional NMR to assign overlapped 1H resonances and to identify proximal interactions between the two constituents. The usefulness of these NMR strategies in mechanistic studies of gastric fat digestion is also discussed.

Suppression of autoimmune disease by dietary n-3 fatty acids

Previous studies have demonstrated that dietary fish oil preparations have anti-inflammatory effects in humans and in experimental animals, but the individual components of fish oils that are responsible for their anti-inflammatory effects have not been documented. We therefore investigated in (NZB x NZW)F1 mice, a model for human systemic lupus erythematosus, the effects of diets containing ethyl esters of two purified n-3 fatty acids, eicosapentaenoic acid (EPA-E) and docosahexaenoic acid (DHA-E), a refined fish oil triglyceride (FO) which contained 55% n-3 fatty acids, and beef tallow (BT) which contains no n-3 fatty acids. The diets were initiated prior to the development of overt renal disease at age 22 weeks, and continued for 14 weeks. The extent of the renal disease was quantified by light microscopy and by proteinuria. Diets containing either 10 wt% FO, 10% EPA-E, or 6% or 10% DHA-E alleviated the severity of the renal disease, compared to the BT diet, whereas diets containing either 3% or 6% EPA-E or 3% DHA-E were less effective. Two diets containing approximately 3:1 mixtures of EPA-E and DHA-E alleviated the renal disease to a greater extent than expected for either of these fatty acids given singly. We believe that these experiments provide the first demonstration of anti-inflammatory effects of individual dietary n-3 fatty acids. The results also indicate that the anti-inflammatory effects of fish oils depend on synergistic effects of at least two n-3 fatty acids.

Novel neurite growth-inhibitory properties of an astrocyte proteoglycan

Conditioned medium (CM) of primary cultures of GFAP-positive adherent astrocytes from neonatal rat neocortex contained a chondroitin sulphate/dermatan sulphate proteoglycan (CDSPG) that co-eluted with a heparan sulphate proteoglycan (HSPG) by ion-exchange chromatography. The CDSPG was resolved from the HSPG by molecular sieve chromatography, which indicated that the molecular mass of the HSPG was greater than 300 kDa, while that of the CDSPG was approximately 50 kDa. Specific lyase digestion and urea/polyacrylamide gel electrophoresis established the homogeneity of the CDSPG and suggested molecular masses of the core protein and glycosylated protein as 54 kDa and 58 kDa respectively. Virtually all of the poly-D-lysine substrate-bound proteoglycan-associated neurite growth-promoting activity of astrocyte CM was accounted for by the HSPG. On poly-D-lysine the immobilized CDSPG displayed little neurite growth-stimulatory activity relative to the HSPG. However, the CDSPG inhibited the potent growth-promoting activity of the HSPG by displacing it from the poly-D-lysine substrate. Differential cellular regulation of production of growth-modulatory proteins with different binding avidity for the substrate of growth may determine the success of a regenerative axonal response by fully competent neurons.

Candida zeylanoides causing candidiasis as tinea cruris

Candida zeylanoides caused candidiasis as tinea cruris in 4 cases. Candida zeylanoides were characterized by good growth of the strain in malt medium, potato dextrose agar and Sabourard's agar. Their colony was milky white and greasy with smooth surface. The diameter of the colony reaches 12 mm within a week. As candida type pseudohyphae but not hyphae, they do not produce ascospore and bolospore. Carbon sources fermentation showed positive results. Nitrogen sources assimilation agar (KNO3) negative, arbutin agar negative, nonvitamin medium positive. G+C mol% value of their DNA was 51.24. Animal experiment showed that guinea pigs were infected by Candida zeylanoides. The main feature of candidiasis as tinea cruris caused by the strain was pink infiltrative erythema with clear margin, a lot of grain-sized papules, a few vesicles, and thin scales. The disease can be cured by preparation of ketoconazole.

Species-specific signals for the splicing of a short Drosophila intron in vitro

The effects of branchpoint sequence, the pyrimidine stretch, and intron size on the splicing efficiency of the Drosophila white gene second intron were examined in nuclear extracts from Drosophila and human cells. This 74-nucleotide intron is typical of many Drosophila introns in that it lacks a significant pyrimidine stretch and is below the minimum size required for splicing in human nuclear extracts. Alteration of sequences of adjacent to the 3' splice site to create a pyrimidine stretch was necessary for splicing in human, but not Drosophila, extracts. Increasing the size of this intron with insertions between the 5' splice site and the branchpoint greatly reduced the efficiency of splicing of introns longer than 79 nucleotides in Drosophila extracts but had an opposite effect in human extracts, in which introns longer than 78 nucleotides were spliced with much greater efficiency. The white-apricot copia insertion is immediately adjacent to the branchpoint normally used in the splicing of this intron, and a copia long terminal repeat insertion prevents splicing in Drosophila, but not human, extracts. However, a consensus branchpoint does not restore the splicing of introns containing the copia long terminal repeat, and alteration of the wild-type branchpoint sequence alone does not eliminate splicing. These results demonstrate species specificity of splicing signals, particularly pyrimidine stretch and size requirements, and raise the possibility that variant mechanisms not found in mammals may operate in the splicing of small introns in Drosophila and possibly other species.

Regenerative neurite growth modulation associated with astrocyte proteoglycans

Adherent GFAP-positive cells of neocortical origin in vitro produce and release members of three families of sulphated proteoglycans and a sulphated protein that copurifies with heparan sulphate proteoglycan (HSPG). Conditioned medium (CM) and the proteoglycans contained in the CM have neurite growth-promoting activity when immobilized on defined substrates of growth but not when in the nonimmobilized compartment. On a poly-D-lysine substrate, the rank ordering of specific neurite growth activity based on protein concentration was 330 kDa HSPG >> 100 kDa HSPG/chondroitin sulphate (CS) PG mixture or hybrid > 330 kDa CSPG > 50 kDa CSPG/dermatan sulphate (DS) PG mixture or hybrid and the 31 kDa sulphoprotein. Astrocyte CM lost its growth facilitatory activity when prepared and released by astrocytes in the presence of soluble mediators of inflammation. Loss of activity could not be explained by qualitative or quantitative alterations of released proteoglycans but appeared to be associated with the presence of an inhibitor. The sulphoprotein that copurified with HSPG was a potent inhibitor of HSPG-mediated neurite growth.

[Facilitatory effect of Pinellia ternata lectin on quantal release of acetylcholine from nerve terminals]

Pinellia ternata lectin (PTL) extracted from the rhizome of Pinellia ternata Briet by porcine thyroglobulin-Sepharose 4B column exhibits hemagglutination activity and carbohydrate binding specificity for mannan. Here we reported the effects of PTL on the resting membrane potential of muscle fiber and on the release of acetylcholine (ACh) from the motor nerve terminals in the phrenic nerve diaphragm preparations of mice. The results showed that PTL increased the frequency of miniature end-plate potential (MEPP). In 30 min after the treatment of the preparation with lectin 100 micrograms.ml-1, the frequency of MEPP reached 20 times higher than that of the control. Addition of mannan 1 mg.ml-1 restored the raised discharge of MEPP to its control level immediately. Similar to the effect of PTL on MEPP frequency, the amplitude and mean quantal content of end-plate potential also increased after PTL. At 100 micrograms.ml-1, the lectin depolarized the muscle membrane slightly, while at 10 micrograms.ml-1 no effect on the membrane potential was found. These results were interpreted as the intracellular Ca2+ elevation due to a permeability increase of the nerve terminal to ions after PTL.

[Effects of mixture of Astragalus membranaceus, Fructus Ligustri lucidi and Eclipta prostrata on immune function in mice]

A Chinese medicine mixture containing Astragalus membranaceus, Fructus Ligustri Lucidi and Eclipta prostrata(AFE), was fed to mice 9g/kg, 20g/kg, respectively for seven days. Observe the effects of AFE on the immune function in mice. The experiment showed that the two dosages of AFE could obviously raise the conversion percentage of lymphocytes (P < 0.01) and serum IgG level (41%-47%) of the mice. The weights of the thymus and spleensed increased in the two groups compared with those in the normal control. The larger dosage of AFE could also raise activity of Adenosine Deaminase (ADA) obviously (P < 0.01). AFE turned out a resistance to the immunosuppressive effect caused by cyclophosphamide.

[Cation channels formed in lipid bilayer by Pinellia ternata lectin]

Pinellia ternata lectin (PTL), a protein exhibiting hemagglutination activity and carbohydrate binding specificity to mannan was purified from rhizome of Pinellia ternata. In this work the actions of PTL on artificial lipid bilayer were investigated by means of the two-compartment system of Mueller and Rudin. The lipid bilayer with resistance more than 10G omega was formed by a solution of lecithin and cholesterol (20 mg/ml and 5 mg/ml respectively) in N-decane. The electrical properties of the lipid bilayer were investigated in voltage clamp mode. Several minutes after the addition of PTL (2 micrograms/ml) in one compartment the channel-like noise as well as a decrease of the resistance of the bilayer were observed. These actions were inhibited by mannan significantly. The resistance increase of the bilayer with PTL-channels could be observed from 2G omega to control level (greater than or equal to 10 G omega) immediately after addition of 40 micrograms/ml mannan. The discrete conduction steps were recorded at low concentration of PTL and at low holding potential. The predominant unit conductance was 35pS in symmetric KCl solution of 100 mmol/L. The selectivity of PTL-channel was estimated from Goldman-Hodgkin-Katz equation by measurement of the reversal potential in an asymmetrical salt solution. The results showed that PTL-channels were cation selective.

Altered processing of integrin receptors during keratinocyte activation

We used monoclonal antibodies against specific integrin subunits to examine the role of integrin receptors in keratinocyte activation. We found that before activation, beta 1 subunits in keratinocytes showed a diffuse distribution, whereas after activation, keratinocytes organized beta 1 receptors into marginal adhesion plaques. In immunoprecipitation experiments with antibodies against beta 1 integrin subunits, we found mostly immature subunits synthesized in keratinocytes freshly harvested from skin. Moreover, integrin receptor complexes immunoprecipitated from these cells by monoclonal antibodies against alpha 2, alpha 3, or alpha 5 subunits contained only immature beta 1 subunits. With keratinocytes cultured 4-7 days, anti-beta 1 antibodies immunoprecipitated mostly mature beta 1 subunits, and integrin complexes immunoprecipitated from cultured cells by anti-alpha subunit antibodies contained mostly mature beta 1 subunits. Antibodies directed against beta 1 subunits also inhibited keratinocyte migration. Based on these results, we suggest that up-regulation of migration by activated keratinocytes depends on changes in processing of pre-beta 1 subunits to mature beta 1 subunits. We also studied the distribution of integrin subunits in skin and on keratinocytes migrating out of skin explants. Whereas beta 1, alpha 2, and alpha 3 subunits were detected in keratinocytes in skin and migrating out of explants, alpha 5 subunits were observed only in migrating cells.

Analyses of Phaseolus vulgaris L. and P. coccineus Lam. hybrids by RFLP: preferential transmission of P. vulgaris alleles

Restriction fragment length polymorphism (RFLP) was determined among P. vulgaris genotypes and Phaseolus species using 19 probes. The incidence of polymorphism was high (70-86%) between species, but relatively low (22-26%) between genotypes of P. vulgaris. Suitable probes were identified for the analysis of P. vulgaris and P. coccineus hybrids. The segregation pattern in F2 populations was Mendelian for two probes (LHB and VEE20) and non-Mendelian for GS-g, CHS, and CHI. Statistical analyses indicated gametic selection with preferential transmission of the P. vulgaris alleles, which may account for the selective recovery of P. vulgaris progeny types observed earlier. The available hybrids of P. vulgaris and P. coccineus and the high degree of interspecific RFLP will facilitate the construction of a linkage map for Phaseolus.

[Histopathological studies on glottic cancer by serial sections]

In 31 glottic cancer specimens from partial laryngectomy, the histopathological findings were compared with vocal cord motility and 5-year survival rate. Among the 31 cases, 7 had ventricular involvements, in which 3 were transglottic tumors; 2 had had their framework destroyed. Eight cases had anterior commissure involvement. Only one had the tendon affected. Of 20 cases with mobile cords, the lesions were entirely superficial to the conus elasticus. Only a few specimens showed minimal invasions of the arytenoid region. Of 8 cases with limited vocal cord motility, invasion of the thyroarytenoid muscle was quite apparent, 4 specimens had the arytenoid areas surrounded by nests of tumor cells, and one case had local recurrence 12 months after operation. There were 3 cases with vocal cord fixation, 2 with subglottic extensions showed cricoid cartilage involvement and had had recurrences 10 and 12 months after operation. Another one with transglottic lesion was controlled by middle portion subtotal laryngectomy. Nine cases had subglottic involvement. One with transglottic lesion had recurrence, the other with arytenoid invasion had local recurrence. In two more recurrent cases, tumors cells spreaded submucosally toward the infraglottic area.

Activation of human keratinocyte migration on type I collagen and fibronectin

The purpose of our studies was to learn more about the regulation of keratinocyte migration. Human keratinocytes freshly harvested from skin were relatively immotile cells, whereas keratinocytes harvested from cell culture migrated on type I collagen or fibronectin as measured in a phagokinesis assay. Development of migratory competence by keratinocytes varied depending on the culture substratum. Cells cultured on plastic were activated more quickly and to a greater extent than cells cultured on dermis. The effect of the culture substratum on migratory competence was reversible. That is, cells cultured on plastic showed reduced activity after subculture on dermis. Cells cultured on dermis showed increased activity after subculture on plastic. Freshly isolated as well as cultured keratinocytes contained beta 1 integrin subunits, but only cultured cells were able to organize the subunits into focal adhesions. These adhesion sites also contained vinculin. In epidermal explants, beta 1 integrin subunits were mostly in basal cells, often more prominent between lateral cell borders than at the epidermal-dermal interface. In keratinocytes that migrated out of skin explants, there appeared to be an increase in the intensity of beta 1 integrin subunit immunostaining, possibly because of the change in shape of migrating cells. Also, beta 1 integrin subunits were found around and beneath migrating keratinocytes. These results show that changes in the distribution of beta 1 integrin subunits accompany development of migratory competence.