Control of src kinase activity by activators, inhibitors, and substrate chaperones

The activities of src tyrosine kinases are greatly influenced by substrate modulators (chaperones). In the presence of bovine serum albumin, the phosphorylation of a random polymer of glutamic acid, alanine, and tyrosine (1:1:1) by src kinases is stimulated 20- to 100-fold, but there is little stimulation with a polymer of glutamic acid and tyrosine (4:1) as substrate. This suggests that serum albumin interacts with the substrates rather than with the enzyme. groEL and several other heat shock proteins also stimulate the phosphorylation of a random polymer of glutamic acid, alanine, and tyrosine (1:1:1). In the absence of substrate modulators, the phosphorylation of calmodulin and of several ras proteins by src kinase is barely detectable. In the presence of polylysine or protamine, marked phosphorylation is observed. Another type of control of src kinase activities appears to be directed toward the enzyme rather than the substrate. Triton X-100 extracts of plasma membranes of bovine brain contain a heat-stable factor that stimulates c-src kinase activity with any of the polymers as substrate. The same extract contains a heat-labile factor that preferentially inhibits c-src kinase activity. The two factors are separated by DEAE-Sephacel and phosphocellulose chromatography. The presence of the activator enhances the potency of the inhibitor.

[Comparative study of Campylobacter pyloridis and Campylobacter jejuni under electron microscope]

Specimens were made by preparing the ultrathin sections after negative staining and ruthenium red staining. The specimens were observed under electron microscope. Results revealed that the shapes of Campylobacter pyloridis (Cp) and C. jejuni (Cj) were similar, but distinctive differences in their structures were observed. Cp had one to five sheathed flagella at one end with bulbous tips. Cj had only one unsheathed flagellum on each end without a bulbous tip. The cell body of Cp was longer than that of Cj. A layer of thick and dense delicate filament-like substance was attached to the surface of the cell body of Cp in the ultrathin sections with ruthenium red staining, in the case of Cj only a little of such a substance could be noted.

[Prenatal sex identification with biotinylated human Y-specific DNA probe]

Using biotinylated human Y-specific DNA probe PHY2.1 and Cos 84, we carried out Southern and dot hybridization with human DNA from artificially aborted chorionic villi, and with DNA of peripheral lymphocytes from normal male and female. The results show that PHY2.1 may be applied in prenatal sex identification both by Southern and by dot hybridization but with Cos 84, only Southern hybridization could be used.

The changes of BPA level in 31 cases of children with aplastic anaemia and its clinical significance

Burst-promoting activity (BPA) was measured in the sera from 31 children with aplastic anaemia (AA). BPA levels were elevated in most of the children with AA (65.2%), the mean value (137.7 +/- 18.4%) being significantly higher than that in normal children (69.6 +/- 9.4%), in children in the recovery period and in children with non-aplastic anaemia. There was a negative relationship between the BPA level in children with AA and the peripheral haemoglobin concentration. The BPA level was higher in those whose duration of illness was shorter than 1 year. In three cases of AA caused by chloramphenicol and benzene hexachloride and one case of congenital pure red cell AA, the BPA level was not elevated. Eleven patients received fetal liver cell suspensions intravenously (FLI). After FLI the BPA level in their sera was significantly reduced. According to these results, it appears that the elevation of BPA level is a special phenomenon of AA. The measurement of BPA in serum is helpful for differentiation between AA and other kinds of anaemia. The elevation of the BPA level in serum is a biological compensation for the haematopoietic disorder, and the measurement of BPA in the serum of patients with AA may be helpful in evaluating the haematopoietic condition.

[Purification and characterization of beta-N-acetyl hexosaminidase from Aspergillus tamarii]

A beta-N-acetylhexosaminidase from mycelium-free culture filtrate of Asp tamarii S215 was purified to PAGE homogenous by ammonium sulfate and polyethylene glycol fractionation precipitation followed by Sephadex G-50 desalt, DEAE-Sephadex A-25 chromatography, hydroxyapatite chromatography and DEAE-Sephadex A-25 rechromatography with 170-fold purification and 24.7% recovery. The ratio of the beta-GlcNAcase and beta-GalNAcase was 2.5 and remained constant throughout the purification. The Mr estimated with concentration gradient PAGE was 140,000 and subunit Mr determined with SDS-PAGE was 72,000, the number of subunit were 2. The pI was 4.2 determined by PAGIEF. The optimum pH was 5.5-6.5 and 5.0-6.0 for beta-GlcNAcase and beta-GalNAcase respectively with stable pH range 5.5-8.3 for both. The optimum temperature was 60 degrees C for beta-GlcNAcase and beta-GalNAcase. The residual activity of beta-GlcNAcase was 52.7% after treated at 50 degrees C for 8 h and it was 44.9% for beta-GalNAcase. The residual activities of both were down to 1% after treated at 62 degrees C for 10 min. The activity was slightly activated by Mn2+ or Fe2+, while strongly inhibited by Hg2+ and slightly by Ag+, Cu2+, Pb2+, Cd2+ or Zn2+. Analyses of amino acids composition showed that the beta-HexNAcase contained about 24.2% acidic amino acids and 14.9% basic amino acids and only 0.6% methionine.

[Study on change in zinc concentration for diabetic cataractous lenses in rats by means of XIXA]

The SD rats were injected with streptozotocin to induce diabetic cataract. Element Zn as well as K, Ca, Mn, Fe, Cu, Pb, Se, etc. in the eye lenses was determined by means of X-ray induced X-fluorescence analysis (XIXA). Compared to values for normal healthy rats, the concentration of Zn and Fe in the cataractous lenses increased, the concentration of K decreased, and that of the others did not change prominently. The change in Zn concentration was probably to meet the needs of the metabolic adjustment in the eye lenses, which would not be the reason for directly inducing diabetic cataract.

Micro-vitreous surgery combined with scleral encircling for the management of complex retinal detachment

50 cases (50 eyes) of various complex retinal detachments (RD) were treated with a combination of vitrectomy, membrane peeling, intraocular air tamponade and scleral encircling. RD with opaque media, RD with proliferative vitroretinopathy, traction RD due to trauma or other factors, RD with posterior breaks, and giant tears were included. During the follow-up periods of 3-12 months, 27 cases (54%) obtained anatomic reattachment, 23 failed (46%). Of the successful case, 24 eyes achieved improvement, 2 eyes remained unchanged, and one eye became worse in their vision. The surgery complications were: retinal haemorrhage, choroidal haemorrhage, iatrogenic tears, and the development of cataract.

[Electron spin resonance (ESR) study on hair of rats with diabetic cataract]

The hair taken from 40 rats with diabetic cataract and 20 normal controls was tested by using ESR. It was found that the 'g factor' of the hair of the rats with diabetic cataract is higher than that in normal controls. The intensity of ESR signals of the hair taken from rats with diabetic cataract is three times higher than that of ESR signals of the hair from the normal controls. The results have suggested a good reappearance and a remarkable increase in number of the free radicals and other particles of paramagnetic substances during the course of the development of the rats' diabetic cataract. The study provides new scientific data for the theory of free radicals damaging to the crystal in the process of the formation of diabetic cataract.

[Detection of sorbitol content in crystalline lens of normal rats and rats with diabetic cataract by 1H-NMR]

The pulse Fourier NMR was employed to measure the artificial diabetic cataract lens at various stages of its formation, and the lenses of the normal rats. Data obtained by using this method show that all the peaks that of water concentrate in the range of delta less than 4 ppm. The peak value at delta = 3.20 ppm is on a marked increase during the formation of cataract which is caused by the phosphate metabolites, such as GPC, ATP, ... etc, in cataract lens. With the development of the disease, the peak width at delta = 3.73 ppm becomes greater and greater, which shows that the activity of sorbitol dehydrogenase has decreased. This leads to a high concentration of the sorbitol in the cataract lens. Consequently, the osmosis pressure in the cataract lens is increased, and excessive water might dip into the crystalline lens to keep the balance of the osmosis pressure. And this might result in the hydration of the fiber cell of the crystalline lens, which might cause a swelling or blisters. These results are in favour of the prolongation of the relaxation time of cataractous lens reported in our other papers, and also support those gained by biochemical studies issued in the medical literature.

A New Minor Saponin from the Leaves of Panax ginseng

Seventeen compounds were isolated from the leaves of PANAX GINSENG C. A. Meyer. Among them, a new minor saponin was established as 3beta,6alpha,12beta-trihydroxy-dammar-20(22), 24-diene-6- O-alpha- L-rhamno-pyranosyl-(1-->2)-beta- D-glucopyranoside ( 2). Fourteen compounds were identified as 20( R)-protopanaxadiol ( 1), 20( R)-protopanaxatriol, ginsenoside-Rh (3), 20( R)-ginsenoside-Rh (2), 20( S)-ginsenoside-Rh (2), ginsenoside-Rh (1), -Rg (3), -Rg (2), -Rg (1), -Re, -Rd, -Rc, -Rb (2), -Rb (1); the others are still under investigation.

[Study on the variation of relaxation time in diabetic cataractous lenses of rats by using NMRA]

Nuclear magnetic resonance analysis (NMRA) was used to measure the relaxation time T1 and T2 of the protons in the different-stage-diseased lenses of rats with diabetic cataract caused by the streptozotocin, and the results were put in comparison with those obtained from the control group, showing that after one month of medication the values of T1 and T2 in the cataractous lenses are greater than those gained from the control group. The variation, as time goes on, becomes greater and greater. T1 and T2 indicate the speed of the free induction decay (FID) signals, and the variation of the FID signals are in direct proportion to that of the proton content of the samples. This shows that an increase in T1 and T2 indicates an increase in the water content in the diseased lenses, and the changes in ratio of "bound" water to free water. Such changes may be explained that the space for "bound" water is occupied by some other macromolecules, causing the alteration of the macromolecular structure, and consequently the aggregation of protein and the degeneration or dehydration or dehydration of the membrane occur, which may give rise to another scattering centre. So the scattering of the lens increases and its transparency decreases. This result is in agreement with some reports in the medical literature. As T1 and T2 are quite different in the normal and pathological tissues, and the protons are the most extensive nucleus in all biological tissues, NMR is a very important method to determine the proton relaxation time in the biological tissue and to judge if it is normal or not.(ABSTRACT TRUNCATED AT 250 WORDS)

Birefringent tuning double frequency He-Ne laser

Experimental details are given of a novel, promising kind of double frequency laser-with power output of 0.8-1.4 mW, large frequency difference from 37 MHz to a longitudinal mode interval, and frequency stability of 10(-5), and its potential uses are discussed.

[Volatile components of herbal Cynomorii]

The volatile components were obtained from Herba Cynomorii for the first time (yield 0.02%). These components were analysed by TLC and GC-MS. Twenty-two compounds, including the main components hexadecanoic acid and 9-octadecenoic acid, were identified. Their percent contents were given.

[Separation of 20(S)-ginsenoside-Rg2 and its 20(R) epimer by reversed phase low pressure column (Rp-18) chromatography]

20(S)-Ginsenoside-Rg2 and its 20(R) epimer were successfully separated using reversed-phase low pressure column (Rp-18) chromatography. The method has proved very convenient and rapid.

Involvement of type I hypersensitivity in rapid rejection of Trichinella spiralis from adult rats

The role of type I hypersensitivity in the rapid rejection of Trichinella spiralis from actively and passively immunized rats was examined. Net intestinal fluid secretion, which occurs during the rejection of the parasites, was used to verify the expression of local anaphylaxis and was examined for its possible role in the rejection process. Worm establishment in the small intestine 30 min after intraduodenal inoculation was significantly reduced in rats that were passively immunized with immune serum containing anti-Trichinella IgE as compared with recipients of normal serum. Worm-induced fluid secretion in immune rats was completely inhibited by the combined action of indomethacin and diphenhydramine. However, worm rejection was not affected. L-651,392, a 5-lipoxygenase inhibitor, also failed to prevent rejection. Ketanserin (a serotonin S2 receptor antagonist) and MDL-72222 (a serotonin S3 receptor antagonist) together blunted the rapid rejection response and reduced fluid secretion. Furthermore, intra-arterial perfusion of serotonin into nonimmune rats caused fluid secretion and reduced worm establishment. In nonimmune rats prostaglandin E2, cholera toxin, and hypertonic Krebs-mannitol solution were used to evoke the same level of intestinal fluid secretion as that induced by reinfection in immune rats or by serotonin in nonimmune hosts. When larvae were inoculated into the secreting gut, their infectivity was unaffected. The results suggest that anaphylaxis is involved in the rapid rejection of T. spiralis in immune rats and that serotonin is a possible chemical mediator of worm rejection. Although the mode of action of serotonin in the rejection process remains unknown, its possible involvement through fluid secretion can be ruled out.

[Studies on the susceptibility among geographic strains of Aedes albopictus in China to infection with dengue viruses]

The comparative susceptibility to dengue serotype 1, 2 and 4 viruses infection of 9 geographic strains of Azdes albopictus was studied by means of experimental feeding the mosquitoes on pledgets soaked with virus-erythrocyte suspension and intrathoracic inoculation with dengue viruses. Variation in susceptibility for both dengue serotypes 1 and 2 was found among the geographic strains by feeding, but no significant difference among those by intrathoracic inoculation. It was evident that a "gut barrier" was involved. Thresholds of oral infection were not the same for dengue serotypes 1, 2 and 4. In terms of infection rate, Haikou strain was more susceptible to all three serotypes of viruses; Beijing and Chengdu strains were more susceptible to serotypes 1 and 2, respectively. All the geographic strains were more susceptible to dengue serotype 2 comparing with other two serotypes. The mosquito head squash method for demonstrating dengue virus antigen by indirect fluorescent antibody technique was modified by mosquito brain tissue smear. This would be more accurate in detecting the dengue virus antigen in the brain tissue.

Jaundiced Gunn rats have increased synaptic delays in the ventral cochlear nucleus

Recordings were made in vitro from cochlear nuclei of Gunn rats, a strain with a recessive mutation that predisposes rats to hyperbilirubinemia at birth. Delays between shocks to the auditory nerve and earliest synaptic responses of the cochlear nuclear neurons were on average longer in Gunn rats than in heterozygotes. Injections of sulfonamide further increased average synaptic delays in jaundiced rats. Responses to injected current in rats were like those in mice.