Study of major flavonoids in crude Scutellariae Radix by micellar electrokinetic capillary chromatography

A method of micellar electrokinetic capillary electrophoresis for determining the six flavonoids in Scutellariae Radix (i.e., baicalin, baicalein, wogonin 7-O-glucuronide, wogonin, oroxylin A 7-O-glucuronide, and oroxylin A) has been developed. The buffer solution (pH 7.24) composed of 20 mM sodium dodecyl sulfate (SDS), 20 mM sodium dihydrogen phosphate, and 25 mM sodium borate was found to be the most suitable electrolyte for the separation. The contents of the six flavonoids in crude Scutellariae Radix could easily be determined within about 15 min. On-column UV (254 nm) monitoring allowed the quantitative determination of baicalin. The effects of pH, surfactant concentration, and applied voltage on the migration behavior of the solutes were studied.

Structure-based design, synthesis, and biological evaluation of irreversible human rhinovirus 3C protease inhibitors. 1. Michael acceptor structure-activity studies

The structure-based design, chemical synthesis, and biological evaluation of peptide-derived human rhinovirus (HRV) 3C protease (3CP) inhibitors are described. These compounds incorporate various Michael acceptor moieties and are shown to irreversibly bind to HRV serotype 14 3CP with inhibition activities (kobs/[I]) ranging from 100 to 600 000 M-1 s-1. These inhibitors are also shown to exhibit antiviral activity when tested against HRV-14-infected H1-HeLa cells with EC50's approaching 0.50 microM. Extensive structure-activity relationships developed by Michael acceptor alteration are reported along with the evaluation of several compounds against HRV serotypes other than 14. A 2.0 A crystal structure of a peptide-derived inhibitor complexed with HRV-2 3CP is also detailed.

Structure-based design, synthesis, and biological evaluation of irreversible human rhinovirus 3C protease inhibitors. 2. Peptide structure-activity studies

The structure-based design, chemical synthesis, and biological evaluation of various peptide-derived human rhinovirus (HRV) 3C protease (3CP) inhibitors are described. These compounds are comprised of an ethyl propenoate Michael acceptor moiety and a tripeptidyl binding determinant. The systematic modification of each amino acid residue present in the binding determinant as well as the N-terminal functionality is described. Such modifications are shown to provide irreversible HRV-14 3CP inhibitors with anti-3CP activities (kobs/[I]) ranging from 60 to 280 000 M-1 s-1 and antiviral EC50's which approach 0.15 microM. An optimized inhibitor which incorporates several improvements identified by the structure-activity studies is also described. This molecule displays very rapid irreversible inhibition of HRV-14 3CP (kobs/[I] = 800 000 M-1 s-1) and potent antiviral activity against HRV-14 in cell culture (EC50 = 0.056 microM). A 1.9 A crystal structure of an S-alkylthiocarbamate-containing inhibitor complexed with HRV-2 3CP is also detailed.

Expression of GDNF family receptor components during development: implications in the mechanisms of interaction

Glial cell line-derived neurotrophic factor (GDNF) and a related factor, neurturin, promote survival of diverse groups of neurons. Both GDNF and neurturin signal via a two-component receptor complex that consists of a ligand-binding GDNF family receptor (GFRalpha-1 or GFRalpha-2) and the receptor protein tyrosine kinase Ret. Recently, a third receptor related to GFRalpha-1 and GFRalpha-2 has also been isolated and designated GFRalpha-3. Although much is known about the interaction among GDNF family factors, Ret, and the alpha-receptors in vitro, it remains unclear about their interactions in vivo. We show here by in situ hybridization that Ret and the alpha-receptors may be colocalized in the same tissues or expressed separately in projecting and target tissues, respectively, indicating that two distinct modes of interaction between Ret and the alpha-receptors exist in vivo. First, Ret may interact with the alpha-receptors expressed in the same cells (termed interaction "in cis") in many tissues and cell populations that respond to GDNF and/or neurturin, such as the substantia nigra, dorsal root ganglia, spinal cord motoneurons, kidney, and intestine. Second, Ret may interact with the alpha-receptors localized in the target neurons (termed interaction "in trans"). In addition, we present evidence in vitro that GFRalpha-1 mediates Ret activation by GDNF in trans. These observations suggest that there are multiple mechanisms regulating the interaction between Ret and the alpha-receptors that mediates the effects of GDNF family trophic factors on the survival and differentiation of cells and on neuron-target interactions in the nervous system.

Dual action of a ligand for Eph receptor tyrosine kinases on specific populations of axons during the development of cortical circuits

The structural basis of cortical columns are radially oriented axon collaterals that form precise connections between distinct cortical layers. During development, these connections are highly specified from the initial outgrowth of collateral branches. Our previous work provided evidence for positional cues confined to individual layers that induce and/or prevent the formation of axon collaterals in specific populations of cortical neurons. Here we demonstrated with in situ hybridization techniques that mRNA of the Eph receptor tyrosine kinase EphA5 and one of its ligands, ephrin-A5, are present in distinct cortical layers, at a time when intrinsic connections are being formed in the cortex. Axonal guidance assays indicate that ephrin-A5 is a repellent signal for a populations of axons that in vivo avoid the cortical layer expressing ephrin-A5. In contrast to its established role as a repulsive axonal guidance signal, ephrin-A5 specifically mediates sprouting of those cortical axons that target the ephrin-A5-expressing layer in vivo. These results identify a novel function of ephrin-A5 on axonal arbor formation. The laminar distribution and the dual action on specific populations of axons suggest that ephrin-A5 plays a role in the assembly of local cortical circuits.

Characterization of HetR protein turnover in Anabaena sp. PCC 7120

The hetR gene plays an important role in heterocyst development and pattern formation in heterocystous cyanobacteria. The hetR gene from Anabaena sp. PCC 7120 was overexpressed in Escherichia coli. Antibodies raised against the recombinant HetR protein (rHetR) were used to characterize metabolism of the HetR of Anabaena sp. PCC 7120 in vivo. HetR was present at a low level when Anabaena sp. PCC 7120 was grown in the presence of combined nitrogen. Shifting from nitrogen repletion conditions to nitrogen depletion conditions led to a two fold increase of HetR in total cell extracts, and most of HetR was located in heterocysts. The amount of HetR in total cellular extracts increased rapidly after shifting to nitrogen depletion conditions and reached a maximum level 3 h after the shift. Isoelectrofocusing electrophoresis revealed that the native HetR had a more acidic isoelectric point than did rHetR. After combined nitrogen was added to the nitrogen-depleted cultures, the degradation of HetR depended on culture conditions: before heterocysts were fully developed, HetR was rapidly degraded; after heterocysts were fully developed, HetR was degraded much more slowly. The distribution of HetR in other species of cyanobacteria was also studied.

Analysis of cellular location and concentration in vocal fold lamina propria

Studies have shown that the lamina propria plays an important role in voice production. Recent studies have analyzed the presence of different proteins and quantified their extent in the lamina propria, but no similar study has yet been done on cellular makeup. The distribution of three different cell types in the lamina propria of 22 human vocal folds was studied. These types are fibroblasts, macrophages, and myofibroblasts. The roles of these cells in the extracellular matrix are described. Their distribution was quantified with use of an image-analysis system. We arbitrarily divided the lamina propria into five sections (each representing 20% of the lamina propria) and compared cell numbers among these sections. Gender comparisons were also made. From these studies it is evident that the cellular distribution in the lamina propria is not uniform. Fibroblasts were more abundant in the deepest 20% of the lamina propria (p < 0.008), myofibroblasts were more abundant in the most superficial 20% (p < 0.016), and in the 36% of our samples that contained macrophages in the lamina propria, there was a significantly higher number of macrophages in the first 20% of the lamina propria (p < 0.003). The only significant gender difference was that women had twice as many macrophages in the most superficial 20% of the lamina propria as men (p < 0.05). The higher myofibroblast activity in the first 20% could indicate that the superficial layer is a region of constant repair. The increased number of macrophages in the superficial layer likely indicates an inflammatory response to inhalants (because of the role of macrophages in the inflammatory response and the fact that only 36% of the patients showed any macrophage activity at all).

Evidence that HetR protein is an unusual serine-type protease

The hetR gene plays a very important role in cell differentiation of heterocystous cyanobacteria. To understand the mechanism of the hetR gene product in regulation of heterocyst differentiation, the recombinant HetR protein (rHetR) was overproduced in Escherichia coli. Purified rHetR was unstable and degraded easily in solution. Phenylmethanesulfonyl fluoride, a serine-type protease inhibitor, prevented the degradation and was shown to modify covalently rHetR. Dansyl fluoride (DnsF), another serine-type protease inhibitor, also covalently modifies rHetR as shown by electrophoresis and electroblotting of the labeled rHetR and by MS. The labeling of rHetR with phenylmethanesulfonyl fluoride and DnsF was at the same site of rHetR and required Ca2+. S179N-rHetR, a mutant protein from strain 216 of Anabaena PCC 7120, which cannot differentiate heterocysts because of the mutation, was also overproduced and characterized. Although S170N-rHetR still can be labeled with DnsF, no proteolysis was observed, suggesting that Ser179 is involved in proteolytic activity. DnsF-labeled rHetR was digested with trypsin, and the labeled peptide was isolated and sequenced. The labeled peptide matches a sequence from HetR. These results show that HetR is a protease.

Regulation of thalamic neurite outgrowth by the Eph ligand ephrin-A5: implications in the development of thalamocortical projections

The cerebral cortex is parcellated into different functional domains that receive distinct inputs from other cortical and subcortical regions. The molecular mechanisms underlying the specificity of connections of cortical afferents remain unclear. We report here that the Eph family tyrosine kinase receptor EphA5 and the ligand ephrin-A5 may play a key role in the exclusion of the limbic thalamic afferents from the sensorimotor cortex by mediating repulsive interactions. In situ hybridization shows that the EphA5 transcript is expressed at high levels in both cortical and subcortical limbic regions, including the frontal cortex, the subiculum, and the medial thalamic nuclei. In contrast, ephrin-A5 is transcribed abundantly in the sensorimotor cortex. Consistent with the complementary expression, the ligand inhibited dramatically the growth of neurites from neurons isolated from the medial thalamus but was permissive for the growth of neurites from lateral thalamic neurons, which is primarily nonlimbic. Similarly, the growth of neurites from Eph-A5-expressing neurons isolated from the subiculum was inhibited by ephrin-A5. Our studies suggest that the Eph family ligand ephrin-A5 serves as a general inhibitor of axonal growth from limbic neurons, which may serve to prevent innervation of inappropriate primary sensorimotor regions, thus contributing to the generation of specificity of thalamic cortical afferents.

The Eph family receptors and ligands

The Eph family is the largest of all known tyrosine kinase receptor-ligand systems. They are expressed in distinct, but overlapping, spatial and temporal patterns during embryonic development and postnatal life, and function in a variety of morphogenic events. The best known function is their role in the guidance of migration of axons and cells in the nervous system through repulsive interactions. They may also play a role in angiogenesis, tissue patterning, and tumor formation.

Regional, developmental, and cell cycle-dependent differences in mu, delta, and kappa-opioid receptor expression among cultured mouse astrocytes

The diversity of opioid receptor expression was examined in astrocytes in low-density and non-dividing (confluent) cultures from the cerebral cortex, hippocampus, cerebellum, and striatum of 1-day-old mice. Mu, delta, and kappa opioid receptor expression was assessed in individual cells immunocytochemically, by using flow cytometry, and functionally by examining agonist-induced changes in intracellular calcium ([Ca2+]i). Significant spatial and temporal differences were evident in the pattern of expression of mu, delta, and kappa receptors among astrocytes. In low-density cultures, greater proportions of astrocytes expressed mu-opioid receptor immunoreactivity in the cerebral cortex and hippocampus (26-34%) than in the cerebellum or striatum (7-12%). At confluence, a greater percentage of astrocytes in cerebellar (26%) and striatal (30%) cultures expressed mu-immunoreactivity. Fewer astrocytes possessed delta-immunoreactivity in low-density striatal cultures (8%) compared to other regions (16-22%). The proportion of delta receptor-expressing astrocytes declined in the cerebellum but increased in the hippocampus. Kappa-opioid receptors were uniformly expressed by 27-34% of astrocytes from all regions, except in cortical cultures, where the proportion of kappa expressing cells was 38% at low-density and decreased to 22% at confluence. Selective mu (PLO 17; H-Tyr-Pro-Phe (N-Me) -D-Pro-NH2, delta ([D-Pen2, D-Pen5] enkephalin), or kappa (U50,488H; trans-(+/-)-3,4-Dichloro-N-methyl-N-[2-(1-pyrrolidinyl) cyclohexyl] benzeneacetamide methanesulfonate) opioid receptor agonists increased [Ca2+]i in subpopulations of astrocytes indicating the presence of functional receptors. Lastly, opioid receptor immunofluorescence varied during the cell division cycle. A greater proportion of astrocytes in the G2/M phase of the cell cycle were mu or delta receptor immunofluorescent than at G0/G1. When astrocytes were reversibly arrested in G1, significantly fewer cells expressed delta receptor immunofluorescence; however, upon reentry into the cell cycle immunofluorescent cells reappeared. In conclusion, opioid phenotype varies considerably among individual cultured astrocytes, and this diversity was determined by regional and developmental (age and cell cycle dependent) differences in the brain. These in vitro findings suggest astroglia contribute to regional and developmental idiosyncrasies in opioid function within the brain.

Cellular localization of ephrin-A2, ephrin-A5, and other functional guidance cues underlies retinotopic development across species

Avian retinotectal and rodent retinocollicular systems are general model systems used to examine developmental processes that underpin topographically organized neuronal circuits. The two systems rely on guidance components to establish their precise retinotopic maps, but many cellular events differ during their development. For example, compared with the chick, a generally less restricted outgrowth pattern is observed when retinae innervate their targets in rodents. Cellular or molecular distributions of guidance components may account for such differences in retinotopic development across species. Candidate repellent molecules, such as ephrin-A2 and ephrin-A5, have been cloned in both chick and rodents; however, it has not yet been shown in rodents that living cells express sufficient amounts of any repellent components to deter outgrowth. We used a coculture assay that gives cellular resolution of retinotarget interactions and demonstrate that living, caudal superior colliculus cells selectively prevent extension of axons from temporal regions of the retinae. Time-lapse video microscopy revealed the cellular localization of permissive and repulsive guidance components in rodents, which differed from that in chick. To analyze the potential molecular basis for these differences, we investigated the function and localization of ephrin-A2 and -A5. Cells transfected with ephrin-A2 and -A5 selectively repelled retinal axons. Ephrin-A2 and -A5 RNA expression patterns differed across cell populations and between species, suggesting molecular mechanisms and key cellular interactions that may underlie fundamental differences in the development of retinotectal and retinocollicular maps.

[Experimental studies on antitumor activity of new recombinant human tumour necrosis factor in nude mice bearing nasopharyngeal carcinoma]

OBJECTIVE

Nude mice model bearing nasopharyngeal carcinoma were established using nasopharyngeal squamous carcinoma cell line (CNE-2).

METHODS

New recombinant human tumor necrosis factor (NrhTNF-alpha) and carboplatin were administered locally or systemically, single or in combination. The microstructural and ultra-micro-structural changes of carcinoma after administration of NrhTNF-alpha were observed under light and electron microscopes.

RESULTS AND CONCLUSION

1. After treatment, the tumor showed hemorrhage, necrosis, regression, the survival time was prolonged. 2. Locally administered NrhTNF-alpha had more significant antitumor effect than intravenously administered of NrhTNF-alpha. 3. There is a notable synergistic antitumor effect by the combination use of NrhTNF-alpha and carboplatin. 4. Microscopy showed that cell changes mostly took place in plasma especially in mitochondria and endoplosmic reticula. The mitochondria were highly bloated. Besides, some nuclei were condensed and fragmented, resulted in cell death. These studies provide experimental basis for biological treatment of nasopharyngeal carcinoma.

[Relationship between plasma NO and PaO2 of artery blood in the patients with chronic pulmonary heart disease]

The plasma nitric oxide(NO) level in the 28 patients with chronic pulmonary heart disease and health controls were measured. The results showed that NO level in the exacerbating patients and stable patients was significantly lower than that in health controls. The NO level in the patients getting worse was markedly lower than that in the stable patients. The lower the oxygen pressure of the artery blood (PaO2), the lower the NO level. when the patient's situation was improving, the plasma NO level increased with rising PaO2. The plasma NO level in patients was associated with the PaO2. This study suggests that the sustained pulmonary hypertension caused by chronic hypoxia may relate to the reduction of NO synthesis and release, and that NO may play an important role in the pathogenesis in chronic pulmonary heart disease.

GFRalpha-2 and GFRalpha-3 are two new receptors for ligands of the GDNF family

The receptor for glial cell line-derived neurotrophic factor (GDNF) consists of GFRalpha-1 and Ret. Neurturin is a GDNF-related neurotrophin whose receptor is presently unknown. Here we report that neurturin can bind to either GFRalpha-1 or GFRalpha-2, a novel receptor related to GFRalpha-1. Both GFRalpha-1 and GFRalpha-2 mediate neurturin-induced Ret phosphorylation. GDNF can also bind to either GFRalpha-1 or GFRalpha-2, and activate Ret in the presence of either binding receptor. Although both ligands interact with both receptors, cells expressing GFRalpha-1 bind GDNF more efficiently than neurturin, while cells expressing GFRalpha-2 bind neurturin preferentially. Cross-linking and Ret activation data also suggest that while there is cross-talk, GFRalpha-1 is the primary receptor for GDNF and GFRalpha-2 exhibits a preference for neurturin. We have also cloned a cDNA that apparently codes for a third member of the GFRalpha receptor family. This putative receptor, designated GFRalpha-3, is closely related in amino acid sequence and is nearly identical in the spacing of its cysteine residues to both GFRalpha-1 and GFRalpha-2. Analysis of the tissue distribution of GFRalpha-1, GFRalpha-2, GFRalpha-3, and Ret by Northern blot reveals overlapping but distinct patterns of expression. Consistent with a role in GDNF function, the GFRalphas and Ret are expressed in many of the same tissues, suggesting that GFRalphas mediate the action of GDNF family ligands in vivo.

[Morphological histological and UV identification of radix Linderae]

The present paper reports the differences of the root tuber, cylindrical root and stem of Lindera aggregata (Sims.) Kosterm. on the external characteristics of crude drug, internal structures and UV-identification.

[Comparative study on the long-term effect of permanent embolization of hepatic artery with Bletilla striata in patients with primary liver cancer]

From May, 1990 to Sept., 1993 106 cases of primary liver cancer were treated by temporary or permanent hepatic arterial embolization with Bletilla striata powders (permanent, 56 cases) or gelfoam powders (temporary, 50 cases) under controlled technical conditions, in term of degree of tumor necrosis, revascularization of tumor, and long-term effect, the results of Bletilla striata group were better as compared with those of gelfoam group. The 1, 2 and 3 year survival rates were 44.9%, 33.6% and 33.6% in Beltilla striata group while the rates were 48.9%, 31.1% and 16.0% in gelfoam group, suggesting that Bletilla striata is superior to gelfoam as an embolizing agent for hepatic carcinoma.

[Thin membrane nephropathy: 27 cases]

To disclose the prevalence of thin membrane nephropathy (TMN) in China and its clinical and pathological features, we prospectively studied TMN cases including 722 cases of renal biopsies in 2 years. 27 cases (male 7 cases, female 20) were diagnosed as primary glomerulonephritis. The GBM thicknesses of TMN group (n = 27) and control group (n = 32) was 207 +/- 36 nm and 382 +/- 34 nm (P < 0.01) respectively. IF of TMN was negative or trace, near normal morphology or mild mesangial proliferative glomerulo nephritis was observed by LM. A few of them had global glomerular sclerosis or single crescent formation. All TMN patients had microscopic hematuria. About one third (9/27 cases) patients with TMN presented isolated persistent microscopic hemataria, 44.4% (12/27 cases) and 22.2% (6/27 cases) patients with TMN were accompanied with mildmoderate proteinuria and heavy proteinuria (> or = 3.5 g/24 h) or nephrotic syndrome. The patients with heavy proteinuria or nephrotic syndrome had good response to corticosteroid therapy. All patients with TMN had normal renal function, only a few of them had transient hypertension. The results showed that the prognosis of TMN would be regarded as good. The familial history of 15 patients with TMN was investigated, and 47% (7/15 cases) of them had > or = two members with microscopic hematuria in their families. TMN was found in 3.7% (27/722 cases) in total renal biopsies and 11.5% (9/78 cases) in the patients with isolated microscopic hematuria. It suggests that TMN isn't a rare kidney disease in China. Careful EM is a critical method for the correct diagnosis of TMN.

Regulation of topographic projection by the Eph family receptor Bsk (EphA5) and its ligands

Topographic projection is a general feature of brain architecture and is critical for appropriate information processing and coding. Nevertheless, little is known about the mechanisms that govern topographic organization. The Eph family receptor tyrosine kinases and ligands have recently been implicated in the specification of topographic maps. We have shown that Bsk, an Eph family receptor, and its ligands are expressed in a complementary fashion in neurons and targets, respectively, in several neural systems. For example, in the hippocampus, Bsk is expressed in an increasing lateral to medial gradient. In contrast, at least three different ligands, viz., Elf-1, LERK3/Ehk1-L, and AL-1/RAGS/LERK7, are transcribed in complementary (opposing) gradients in the hippocampal subcortical target, the lateral septum. However, the spatial and temporal distribution of the ligands are different, such that combinatorially they specify the full target region during development. Consistent with a key role in hippocamposeptal topographic projection, the ligands selectively inhibit the growth of the topographically inappropriate medial hippocampal neurites but sustain the growth of the appropriate lateral neurites. Our studies indicate that the interaction of Bsk and its ligands restricts the receptor-positive medial neurons to the topographically appropriate, ligand-poor dorsal septal target. In addition to the hippocamposeptal system, Bsk and its ligands are also expressed in afferents and targets of several other systems, including the olfactory and the retinotectal systems. Consequently, Bsk and its ligands may play important roles in neuron-target interactions in multiple neural circuits.

[Resistant antibiotic analysis of methicillin-resistant staphylococcus]

Methicillin-resistant staphylococcus aureus is one of the important patholonic bacteria which cause nosocomial infection. In order to investigate the resistant antibiotic circumstances of this organism and hence provide foundations of prevention and treatment, we determined the resistant rates of 88 staphylococcus strains for methicillin and for other 14 kinds of commonly used antibiotics, and we determined the engendering beta-lactamase. The results showed that the isolation rate of methicillin-resistant staphylococcus aureus (MRSA) was 56%; the rate of methicillin-resistant staphylococcus coagulase-negative (MRSCoN) was 47.6%; the resistance rate and the multi-resistant rate of methicillin-resistant staphylococcus (MRS) for the 14 kinds of antibiotics were higher as compared with those of methicillin-sensitive (MSSA). Among all the tested strains, MRSA was the highest to engender beta-lactamase (92.9%); Methicillin-sensitive staphylococcus coagulase-negative (MSSCoN) was the lowest (39.4%). MRS was sensitive to vancomycin and furantoin. These suggest that when treating this bacterium, we should select these two antibiotics first.

Dynamic expression suggests multiple roles of the eph family receptor brain-specific kinase (Bsk) during mouse neurogenesis

The eph family ligands and receptors have been implicated in mediating topographic neuron-target interactions. We recently isolated Bsk, a new member of the eph family receptors, and showed that it is expressed primarily in the brain. To investigate the role of Bsk in the development of the nervous system, we examined the temporal and spatial patterns of Bsk expression using in situ hybridization. We report here that Bsk expression exhibits dynamic changes during embryogenesis. In early embryos, Bsk is widely transcribed in the nervous system, including the forebrain, midbrain, hindbrain and spinal cord. Bsk expression in the midbrain, hindbrain and spinal cord, however, gradually decreases while in the forebrain increases over time. By embryonic day 18, the most intense Bsk expression was found in the limbic system. High levels of the expression in the limbic system persisted throughout post-natal development and remained stable in the adult up to 24 month. The topography of Bsk expression is in the form of gradients in several regions of the brain, including the lateral septum, spinal cord, as well as the hippocampus. Selective expression was also observed in Purkinje cells. Our findings on the topography of Bsk expression provide support to potential roles of Bsk in topographic projection. Our analyses further suggest that there may be other novel functions of Bsk in early neurogenesis in addition to potential roles in topographic mapping.

[The study on analgesic effect of local-release delivery system--Huangjiabang]

Laboratory investigation was made on analgesic effect of local release delivery system, Huangjiabang, which mainly includes Chinese medical herbs. Through the application of twisting-body and thermal-plate experiments on white rats. The result showed that the pain threshold was markedly elevated (P < 0.05, P < 0.001) after the rats were fed with Huangjiabang 125 mg/kg or 250 mg/kg body weight, and the number of twisting body's animals significantly decreased (P < 0.001). The analgestic mechanism of Huangjiabang delivery system relates to its effect of invigorating the circulation of blood and accelerating the stasis assimilation, remitting the inflammation.

[Inhibitory effects of two oligosaccharides on murine melanoma experimental metastasis]

OBJECTIVE

To observe the effects of a chemically synthesized tetrose and a natural yeast mannan on mouse melanoma experimental liver metastasis.

METHODS

After treated with 4 mg tetrose (tetrose group) or 4 mg mannan (mannan group) for 30 minutes at 37 degrees C, 0.5 ml 1 x 10(6)B16-MBK melanoma cells were injected intraspleen. 55 days later, melanoma metastasis nodes in the surfaces of the liver and other organs as well as mouse survival time were observed.

RESULTS

Of 6 mice in control (B16 cell+PBS), 4 died naturally within 55 days, 2 were dissected in the 55th day. All of the 6 mice had metastases in the livers, the total number of the melanoma nodes on each liver surface ranged from 2 to 30, with the largest one fused to the whole liver. One mouse had a neoplasm in the remnant site of injection, 3 had metastases in lungs, while of the 6 mice in the tetrose group, one died on the 50th day on injection. In mannan group, all of the 6 mice survived and no metastasis was seen except the largest diameter of < 1 mm of 2 liver nodes in one mouse. Neither tetrose nor mannan group had metastasis of the liver, and the weights of liver in the two groups were significantly lower than in the control.

CONCLUSION

Both tetrose and mannan had the effects in blocking melanoma experimental liver metastasis, inhibiting transmigration of the liver, and prolonging the survival time of the mouse.

The intermediate layer: a morphologic study of the elastin and hyaluronic acid constituents of normal human vocal folds

The lamina propria of vocal folds are important in voice production. We evaluated the morphologic features of elastin and hyaluronic acid, two important constituents of the lamina propria. Thirty normal human vocal folds were obtained from patients dying of traumatic causes without vocal fold injury. These tissues were immediately prepared for histologic and ultrastructural examination by standard methods. For specific study of the ultrastructure of the layers of the lamina propria, six vocal folds were divided horizontally through the midplane of the lamina propria. We found that the elastin composition of the vocal folds is variable, the largest amount being seen in the midportion on elastin-van Gieson (EVG) staining and ultrastructural evaluation. The superficial layer of the lamina propria contains fewer large elastin fibers. In this region, we found that elastin was predominantly composed of elaunin and oxytalan, which stain poorly with EVG. Using computer-assisted image analysis, we quantified the differences in elastin composition between the layers. The amount of elastin varied between men and women, and these differences could not be accurately measured by the methods employed. Hyaluronic acid was abundant especially in the midportion of the lamina propria and was significantly more abundant in men than women on quantification. The significance of these observations in normal vocal folds is discussed.

[Reconstruction of lacrimal passage in repair of oblique facial cleft]

For the reconstruction of lacrimal passage in obligue facial cleft, three methods were performed in 4 cases. According to the difference in local pathology canaliculorhinestomy, transfer of vein or oral mucosa, or modified dacryocystorhinostomy was performed. The patients were followed for 6 to 12 months with satisfacting results.

[Method of cyanogen bromide-fluorimetry determination of trace amount of selenomethionine in grain and blood]

Selenomethionine (SeMet) reacted with cyanogen bromide (BrCN) quantitatively forms CH3SeCN. After extracted with CHCl3, the Se of CH3SeCN is acid-digested to Se(IV). Then 2,3-diaminonaphthalene is used to determine the fluorescent Se value of 4,5-benzopiaselenol. The determination limit of this method was 3 ng/g SeMet. The accuracy of 10-500 ng Se in SeMet standard was 91.8%-97.6%. RSD was 1.9%-6.3%. Recoveries for grain and blood were 92.3%-96.7%. RSD was 2.7%-5.1%. The RSD for samples was 2.7%-9.0%. Selenocystine, selenocystiene selenite and methionine did not interfere with the determination.

A multiple wavelength algorithm in color image analysis and its applications in stain decomposition in microscopy images

Stains have been used in optical microscopy to visualize the distribution and intensity of substances to which they are attached. Quantitative measures of optical density in the microscopic images can in principle be used to determine the amount of the stain. When multiple dyes are used to simultaneously visualize several substances to which they are specifically attached, quantification of each stain cannot be made using any single wavelength because attenuation from the several stain components contributes to the total optical density. Although various dyes used as optical stains are perceived as specific colors, they, in fact, have complex attenuation spectra. In this paper, we present a technique for multiple wavelength image acquisition and spectral decomposition based upon the Lambert-Beer absorption law. This algorithm is implemented based on the different spectral properties of the various stain components. By using images captured at N wavelengths, N components with different colors can be separated. This algorithm is applied to microscopy images of doubly and triply labeled prostate tissue sections. Possible applications are discussed.

Detection of ligands in regions anatomically connected to neurons expressing the Eph receptor Bsk: potential roles in neuron-target interaction

Neuron-target interaction is a key feature in the establishment of neuronal networks. However, the underlying mechanism remains unclear. We have shown that at the time of target innervation, Bsk, an eph family receptor, is expressed at high levels in several brain regions including the hippocampus, olfactory bulb, and retina. To study whether the ligands are expressed in the target tissues, we investigated the expression of Bsk ligands using a ligand-affinity probe, Bsk-AP, which consisted of the extracellular domain of Bsk fused in frame with a human placental alkaline phosphatase. These analyses showed that the ligands were expressed at high levels in the developing septum, hypothalamus, olfactory neural epithelium, and tectum. In situ hybridization studies revealed that at least three different factors were responsible for the Bsk-AP binding. In the septum, Elf-1, Lerk3 (Eff-2), and AL-1/Lerk7 were transcribed. In the hypothalamus, AL-1/Lerk7 was the ligand detected by Bsk-AP. In the olfactory system, high levels of Lerk3 were detected in the sensory neurons. Both Elf-1 and AL-1/Lerk7 were present in the tectum. These ligand-positive areas are known to be anatomically connected to Bsk-expressing regions. These observations strongly suggest that Bsk and the ligands participate in neuron-target interactions in multiple systems and provide support for their involvement in topographic projection.

Chemistry of the pyrrolo[1,2-alpha]benzimidazole antitumor agents: influence of the 7-substituent on the ability to alkylate DNA and inhibit topoisomerase II

This study addresses the influence the 7-substituent on the cytotoxicity of pyrrolo[1,2-alpha]-benzimidazole quinones possessing a 6-aziridinyl group (PBIs) and a 6-acetamido group (APBIs). Reduction of a PBI to the aziridinyl hydroquinone results in both nucleophile trapping (alkylation) and 1,5-sigmatropic shift reactions. The latter process is essentially an internal redox reaction wherein the hydroquinone causes reductive opening of the aziridinyl ring. The 7-substituent controls the fate of the aziridinyl ring by means of steric and electronic effects. An electron-rich 7-substituent favors the 1,5-sigmatropic shift reaction. If the 7-substituent distorts the 6-aziridinyl group from the conformation required for the 1,5-sigmatropic shift, then nucleophile trapping occurs. The 7-methyl substituent results in significant nucleophilic trapping, and the 7-unsubstituted and 7-methoxy substituents favor the 1,5-sigmatropic reaction. Thus, the 7-methyl PBIs show the most cytotoxicity of the analogues studied. The APBIs are cytotoxic only as quinones, and reduction to the hydroquinone results in loss of activity. Consistent with this observation, the change from 7-methyl to the more electron-rich 7-methoxy results in a substantial loss of APBI cytotoxicity as well as decreased topoisomerase II inhibition. The mechanism of inhibition is thought to involve the interacalation of only electron deficient APBIs into DNA.

Regulation of topographic projection in the brain: Elf-1 in the hippocamposeptal system

The hippocampus and septum play central roles in one of the most important spheres of brain function: learning and memory. Although their topographic connections have been known for two decades and topography may be critical for cognitive functions, the basis for hippocamposeptal topographic projection is unknown. We now report for the first time that Elf-1, a membrane-bound eph family ligand, is a candidate molecular tag for the genesis of the hippocamposeptal topographic projection. Elf-1 is expressed in an increasing gradient from dorsal to ventral septum. Furthermore, Elf-1 selectively allows growth of neurites from topographically appropriate lateral hippocampal neurons, while inhibiting neurite outgrowth by medial hippocampal neurons. Complementary to the expression of Elf-1, an eph family receptor, Bsk, is expressed in the hippocampus in a lateral to medial gradient, consistent with a function as a receptor for Elf-1. Further, Elf-1 specifically bound Bsk, eliciting tyrosine kinase activity. We conclude that the Elf-1/Bsk ligand-receptor pair exhibits traits of a chemoaffinity system for the organization of hippocamposeptal topographic projections.

Higher in vivo protein binding of etoposide in children compared with adult cancer patients

Etoposide is bound to plasma albumin (94%). Previous studies have revealed altered protein binding of etoposide in cancer patients. This has clinical implications since only the free fraction is considered pharmacologically active. We have studied the etoposide protein binding in 11 children (eight acute lymphocytic leukemia, two malignant histiocytosis, and one oligodendroglioma; age 1-17 years) and 46 adult patients (28 acute myelocytic leukemia, eight lymphoma, one multiple myeloma, and nine small cell lung cancer; age 38-81 years). All patients were treated with etoposide 50-200 mg/m2 i.v. or orally. Plasma from ten healthy volunteers, 26-50 years of age, was spiked with etoposide, 10 micrograms/ml, and the protein binding was compared with that in patient samples. The free etoposide concentration was determined by high performance liquid chromatography (HPLC) after ultrafiltration at room temperature. The free etoposide fraction was lower, 2.5 +/- 0.6% (mean +/- SD), in the children compared with 5.0 +/- 3.6% in adult cancer patients. In plasma from healthy adults it was 3.2 +/- 0.3%. It is concluded that children have significantly lower levels of free etoposide compared with adult patients (P = 0.03) as well as with healthy subjects (P = 0.001), which is likely to affect metabolism and renal clearance as well as cellular uptake of the drug.

DNA damage induced by etoposide; a comparison of two different methods for determination of strand breaks in DNA

Etoposide induces DNA damage to cells by interacting with the nuclear enzyme topoisomerase II. In this investigation the human lymphoblastic leukemia cell line (CEM) was used to study induction of DNA-strand breaks and cellular drug uptake after treatment with etoposide at a concentration of 0.5-2 micrograms/ml. High performance liquid chromatography was used for determination of etoposide concentrations. The alkaline elution assay and the DNA unwinding technique were compared for quantifying strand breaks in DNA induced by etoposide. The concentrations required to increase the level of DNA damage significantly was as follows: the DNA unwinding technique, 0.20 microgram/ml; the alkaline elution assay with proteinase K, 0.45 microgram/ml; the alkaline elution assay without proteinase K, 0.60 microgram/ml. When the half-life was adjusted, considering the efflux time of etoposide from cells, it was found to be only a few minutes. The present data show that the DNA unwinding technique is to be preferred for the screening of DNA damage. This technique is easier and quicker to perform than the alkaline elution technique.

Morphometry and autoradiography of altered rat enamel protein processing due to chronic exposure to fluoride

Female Sprague-Dawley rats had 6 weeks of 0 (control), 75 or 100 parts/10(6) sodium fluoride in their drinking water. Whole mandibular incisors were removed, fixed, demineralized and sections prepared for light-microscopic morphometric analysis of dose-related alterations in enamel protein retention. Other rats given 0 and 75 parts/10(6) only (control and experimental groups) were used for autoradiographic evaluation of alterations in enamel protein removal 35S-methionine was applied directly over secretory ameloblasts at the end of the fifth week of fluoride exposure. Incisors were removed either 5 or 7 days later and processed for autoradiographic analysis. The results indicated: (1) extended retention of enamel proteins in fluoride-exposed maturation enamel as well as reduced enamel protein synthesis and/or secretion in the secretory stage; (2) negative linear correlation between extended enamel protein retention and reduced enamel protein secretion among groups; and (3) repression of enamel protein removal. The data are also consistent with the concept that the fluoride effect is multifactorial.

The Mos/mitogen-activated protein kinase (MAPK) pathway regulates the size and degradation of the first polar body in maturing mouse oocytes

Mos is an upstream activator of mitogen-activated protein kinase (MAPK) and, in mouse oocytes, is responsible for metaphase II arrest. This activity has been likened to its function in Xenopus oocytes as a component of cytostatic factor. Thus, Mos-deficient female mice (MOS-/-) are less fertile and oocytes derived from these animals fail to arrest at metaphase II and undergo parthenogenetic activation [Colledge, W. H., Carlton, M. B. L., Udy, C. B. & Evans, M. J. (1994) Nature (London) 370, 65-68 and Hashimoto, N., Watanabe, N., Furuta. Y., Tamemoto, B., Sagata, N., Yokoyama, M., Okazaki, K., Nagayoshi, M., Takeda, N., Ikawa, Y. & Aizawa, S. (1994) Nature (London) 370, 68-71]. Here we show that maturing MOS-/- oocytes fail to activate MAPK throughout meiosis, while p34cdc2 kinase activity is normal until late in metaphase II when it decreases prematurely. Phenotypically, the first meiotic division of MOS-/- oocytes frequently resembles mitotic cleavage or produces an abnormally large polar body. In these oocytes, the spindle shape is altered and the spindle fails to translocate to the cortex, leading to the establishment of an altered cleavage plane. Moreover, the first polar body persists instead of degrading and sometimes undergoes an additional cleavage, thereby providing conditions for parthenogenesis. These studies identify meiotic spindle formation and programmed degradation of the first polar body as new and important roles for the Mos/MAPK pathway.

[New use of Bletilla striata as embolizing agent in the intervention treatment of hepatic carcinoma]

A Chinese herb, Bletilla striata, was used as embolizing agent in order to improve the therapeutic results of intervention treatment of liver cancer. From October 1991 to January 1995, 56 cases of hepatic carcinoma were treated with Bletilla striata by hepatic artery embolization, with conventional gelform embolization in 50 cases as control. Patients were followed-up for 10-48 months. Embolization with Bletilla striata led to extensive and permanent vascular obstruction, accompanied with marked shrinkage of tumor size and significant decrease in serum AFP levels. Collaterals were few in number and collateral circulation was established late so that the treatment intervals could be prolonged, with an average of 7 months. The 1-, 2-, and 3-year survival rate was 81.9%, 44.9% and 33.6%, respectively, with a median survival time of 19.8 months. All the clinical parameters were better than those treated with conventional gelform embolization. The results indicate that Bletilla striata is an ideal vascular embolizing agent.

AtJ1, a mitochondrial homologue of the Escherichia coli DnaJ protein

The nucleotide sequence of a cDNA clone from Arabidopsis thaliana ecotype Columbia was determined, and the corresponding amino sequence deduced. The open reading frame encodes a protein, AtJ1, of 368 residues with a molecular mass of 41 471 Da and an isoelectric point of 9.2. The predicted sequence contains regions homologous to the J- and cysteine-rich domains of Escherichia coli DnaJ, but the glycine/phenylalanine-rich region is not present. Based upon Southern analysis, Arabidopsis appears to have a single atJ1 structural gene. A single species of mRNA, of 1.5 kb, was detected when Arabidopsis poly(A)+ RNA was hybridized with the atJ1 cDNA. The function of atJ1 was tested by complementation of a dnaJ deletion mutant of E. coli, allowing growth in minimal medium at 44 degrees C. The AtJ1 protein was expressed in E. coli as a fusion with the maltose binding protein. This fusion protein was purified by amylose affinity chromatography, then cleaved by digestion with the activated factor X protease. The recombinant AtJ1 protein was purified to electrophoretic homogeneity. In vitro, recombinant AtJ1 stimulated the ATPase activity of both E. coli DnaK and maize endosperm cytoplasmic Stress70. The deduced amino acid sequence of AtJ1 contains a potential mitochondrial targeting sequence at the N-terminus. Radioactive recombinant AtJ1 was synthesized in E. coli and purified. When the labeled protein was incubated with intact pea cotyledon mitochondria, it was imported and proteolytically processed in a reaction that depended upon an energized mitochondrial membrane.

[Study on local huangjiabang delivery device]

This article reports the pharmacological functions of local Huangjiabang delivery device which mainly includes medicinal herbs. The experimental study showed that Huangjiabang could inhibit the predominant cultivable organisms in periodontal disease significantly, and could also inhibit inflammatory swelling caused by xylene. Jiaochacaijiao, egg serum and filter-paper-granuloma significantly. The preliminary clinical observation showed that GI, PLI, SBI and PD were reduced remarkably in Huangjiabang administered pockets after two days and seven days of treatment. It is suggested that this new direct drug delivery system with medicinal herbs has wide prospect in the treatment of periodontal disease.

[The inhibitory effects of serum of patients with acute promyelocytic leukemia on the formation of megakaryocytopoiesis colony unit]

OBJECTIVES

To determine if the sera of patients with acute promyelocytic leukemia (APL) and all-trans retinoic acid (ATRA) inhibit the formation of colony-forming-unit of megakaryocyte (CFU-Meg).

METHODS

By cellular culture assay, the sera of 22 APL patients treated with ATRA and 10(-6)' mol/L ATRA were kinetically used to perform the investigation. Meanwhile, serum tumor necrosis factor (TNF) activity and bone marrow CFU-L were also detected.

RESULTS

Before treatment, there was an inhibitory activity on CFU-Meg in the serum of APL patients (29.6% +/- 2.4%). The activity reduced gradually with the treatment and was stimulus when bone marrow remission obtained (-18.7% +/- 4.1%, P < 0.001). It was positively correlated with TNF activity in the serum and the number of CFU-L however negatively correlated with the number of megakaryocyte in bone marrow and PLT. Serum TNF activity and the number of CFU-L before treatment were higher than those after treatment (P < 0.05 and < 0.001, respectively). ATRA could stimulate the growth of CFU-Meg.

CONCLUSIONS

There was an inhibitory activity in the serum of APL patients which could be used to monitor the efficacy of the therapy. ATRA stimulates the growth of CFU-Meg.

Branchpoint and polypyrimidine tract mutations mediating the loss and partial recovery of the Moloney murine sarcoma virus MuSVts110 thermosensitive splicing phenotype

Balanced splicing of retroviral RNAs is mediated by weak signals at the 3' splice site (ss) acting in concert with other cis elements. Moloney murine sarcoma virus MuSVts110 shows a similar balance between unspliced and spliced RNAs, differing only in that the splicing of its RNA is, in addition, growth temperature sensitive. We have generated N-nitroso-N-methylurea (NMU)-treated MuSVts110 revertants in which splicing was virtually complete at all temperatures and have investigated the molecular basis of this reversion on the assumption that the findings would reveal cis-acting elements controlling MuSVts110 splicing thermosensitivity. In a representative revertant (NMU-20), we found that complete splicing was conferred by a G-to-A substitution generating a consensus branchpoint (BP) signal (-CCCUGGC- to -CCCUGAC- [termed G(-25)A]) at -25 relative to the 3' ss. Weakening this BP to -CCCGAC- [G(-25)A,U(-27)C] moderately reduced splicing at the permissive temperature and sharply inhibited splicing at the originally nonpermissive temperature, arguing that MuSVts110 splicing thermosensitivity depends on a suboptimal BP-U2 small nuclear RNA interaction. This conclusion was supported by results indicating that lengthening the short MuSVts110 polypyrimidine tract and altering its uridine content doubled splicing efficiency at permissive temperatures and nearly abrogated splicing thermosensitivity. In vitro splicing experiments showed that MuSVts110 G(-25)A RNA intermediates were far more efficiently ligated than RNAs carrying the wild-type BP, the G(-25)A,U (-27)C BP, or the extended polypyrimidine tract. The efficiency of ligation in vitro roughly paralleled splicing efficiency in vivo [G(-25)A BP > extended polypyrimidine tract > G(-25)A,U(-27)C BP > wild-type BP]. These results suggest that MuSVts110 RNA splicing is balanced by cis elements similar to those operating in other retroviruses and, in addition, that its splicing thermosensitivity is a response to the presence of multiple suboptimal splicing signals.

Correlation of survival with quantitative tissue staining of prostate specific acid phosphatase in patients with prostate carcinoma by using microscopic image analysis: a preliminary report of correlative studies on RTOG protocols 75-06, 77-06, and 83-07

PURPOSE

We have previously shown that the intensity (graded semiquantitatively as 1-4+) of tissue prostate-specific acid phosphatase (PSAP) staining determined immunocytochemically in a cohort of prostate carcinoma patients from Radiation Therapy Oncology Group Protocols (RTOG) protocols 75-06 and 77-06 correlated with survival. The extent of this staining was heterogeneous and was estimated. The extent of staining was not found to be significantly associated with survival. We undertook the present quantitative study to see if the improved precision and reliability of measurement of the intensity and extent of prostate specific acid phosphatase staining would confirm and extend our previous observations.

METHODS AND MATERIALS

Patient cohorts representative of the entire group were obtained from RTOG 75-06 plus 77-06 and 83-07. The RTOG 77-06 plus 75-06 patients (No-Hormone population) did not receive preradiation hormonal therapy. RTOG 83-07 patients (Prehormone population) received one of two types of preradiation chemical androgen ablation. In this study, histologic slides of tumors were immunocytochemically stained for PSAP by the peroxidase-antiperoxidase (PAP) technique using diaminobenezidene (DAB) as a substrate and hematoxylin as a nuclear counterstain. The intensity and extent of immunocytochemical PSAP staining (IPSAP stain) was quantified using our dual wavelength and batch mode image process technique.

RESULTS

Our study of 151 cases confirmed that overall survival of patients in both populations was positively correlated with the intensity and extent of IPSAP stain. Results of the two studies were similar. The statistical significance of the relationship of both extent and intensity was greater in the cohort from protocol 83-07, which was the patient group receiving pretreatment with hormones. In a Cox multiple regression analysis including clinical stage, Gleason and M. D. Anderson grades, and the cohort of patients (Prehormone or No-Hormone group) as covariables, both the intensity and extent of the IPSAP stain significantly correlated with survival along with M. D. Anderson grade of the tumor.

CONCLUSION

Quantitative image analysis of the IPSAP stain predicts survival in patients treated with external beam radiotherapy with and without prior hormonal therapy.

Mutagenic analysis of functional domains of the mos proto-oncogene and identification of the sites important for MAPK activation and DNA binding

We constructed in-frame deletion/replacement mutations in the Xenopus mos proto-oncogene that lie within conserved Mos-specific codons, but outside of the regions that are conserved among the src kinase family of genes. All gene products were assayed in vitro for kinase activity and in vivo for their ability to induce oocyte maturation, embryonic cleavage arrest and cellular transformation. Most mutations in Mos eliminated both kinase and biological activity. However, a mutation in Mos that removed two basic amino acid residues (R94 and K97) downstream from the lysine at the ATP binding site (K90) markedly enhanced autophosphorylation activity. Moreover, this mutant displayed markedly reduced biological activity, lacked transforming activity, and failed to activate mitogen activated protein kinase (MAPK). A second mutant Mos product, lacking amino acids R45-A54, displayed a five-fold increase in cellular transforming activity. This Mos mutant specifically localized to the cytoplasm; in contrast to wild-type (wt) Mos that localized to both the nucleus and the cytoplasm. These data indicate that Mos transforming activity is mediated via signalling exerted in the cytoplasm, presumably through MAPK, and that nuclear localization of the oncogene product interferes with transforming activity. We also show that amino acids R45-A54 are important for Mos DNA binding activity.

Electrically evoked auditory brainstem response in peripherally myelin-deficient mice

The integrity of the myelin sheath is important for normal electrophysiological function and survival of neurons that make up the auditory nerve. It is hypothesized that myelin deficiency of the auditory nerve may change the electrophysiologic characteristics of the auditory system, especially the temporal properties. In this study, the electrically evoked auditory brainstem response (EABR) was systematically evaluated in TrJ and Po-DT-A mice. Both of these mice have a deficit of their peripheral myelin. Correlation between the EABR and degree of myelin deficiency was also evaluated. The EABR in both strains of poorly myelinated mice exhibited prolonged latency, decreased amplitude, elevated threshold of wave I evoked by short-duration stimuli (20 microseconds/phase). A 2-pulse stimulation paradigm was used to evaluate refractory properties. Myelin-deficient mice exhibited slower recovery from the refractory state than controls. Long-duration stimuli (4 ms/phase) were used to assess integration properties. Myelin-deficient mice demonstrated prolonged wave I latency and more gradual latency changes with current level. Myelin thickness showed a strong correlation with EABR threshold for short-duration stimulation (r = -0.784), maximum wave I latency (r = -0.778) and the time constant of the wave I latency-current level function (r = -0.736) for long-duration stimulation and normalized wave I recovery functions (r = -0.718). These findings suggest that EABR measurement may be a promising tool to assess the electrically stimulated properties of auditory neurons, particularly related to the status of myelin sheath.