[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.

Anatomical and physiological measures of auditory system in mice with peripheral myelin deficiency

Animal models with genetic abnormalities have been increasingly used in auditory research. Both TrJ mice and Po-DT-A mice are animals with peripheral myelin deficiency. In TrJ mice, the defect is due to a mutated PMP-22 gene. In Po-DT-A mice, the defect is produced by a transgene using the rat Po promotor to direct the expression of gene encoding for the bacterial diphtherial toxin A chain (DT-A). This study evaluates the auditory system both physiologically and histologically in these two strains of mice. Histological examination revealed that there was myelin deficiency of the auditory nerve fibers, accompanied by a loss of dendrites and a loss of spiral ganglion cell bodies in both strains of mice. In general, histological deficits in TrJ mice were greater than those in Po-DT-A mice. There was a strong correlation between the degree of myelin deficiency and the survival of spiral ganglion neurons. ABR measurements exhibited differences in threshold, latency and slope of the ABR growth function between myelin-deficient mice and their respective controls. These results suggest that the integrity of the myelin in the auditory nerve is important both for neural survival and for normal electrophysiological function of spiral ganglion neurons.

Physical and transcriptional map of an aflatoxin gene cluster in Aspergillus parasiticus and functional disruption of a gene involved early in the aflatoxin pathway

Two genes involved in aflatoxin B1 (AFB1) biosynthesis in Aspergillus parasiticus, nor-1 and ver-1, were localized to a 35-kb region on one A. parasiticus chromosome and to the genomic DNA fragment carried on a single cosmid, NorA. A physical and transcriptional map of the 35-kb genomic DNA insert in cosmid NorA was prepared to help determine whether other genes located in the nor-1-ver-1 region were involved in aflatoxin synthesis. Northern (RNA) analysis performed on RNA isolated from A. parasiticus SU1 grown in aflatoxin-inducing medium localized 14 RNA transcripts encoded by this region. Eight of these transcripts, previously unidentified, showed a pattern of accumulation similar to that of nor-1 and ver-1, suggesting possible involvement in AFB1 synthesis. To directly test this hypothesis, gene-1, encoding one of the eight transcripts, was disrupted in A. parasiticus CS10, which accumulates the aflatoxin precursor versicolorin A, by insertion of plasmid pAPNVES4. Thin-layer chromatography revealed that gene-1 disruptant clones no longer accumulated versicolorin A. Southern hybridization analysis of these clones indicated that gene-1 had been disrupted by insertion of the disruption vector. These data confirmed that gene-1 is directly involved in AFB1 synthesis. The predicted amino acid sequence of two regions of gene-1 showed a high degree of identity and similarity with the beta-ketoacyl-synthase and acyltransferase functional domains of polyketide synthases, consistent with a proposed role for gene-1 in polyketide backbone synthesis.

ImmunoMax. A maximized immunohistochemical method for the retrieval and enhancement of hidden antigens

BACKGROUND

Since the introduction of mAb, immunohistochemistry has become an important tool in research and in surgical pathology. The most widely used fixative in routine histopathology is formaldehyde, and it has become the gold standard for morphologic tissue preservation. Although the molecular mechanism underlying the tissue fixation is not well understood, it has become clear that available immunoreactive Ag are progressively lost during the fixation process. For a long time, it was thought that formalin-sensitive Ag might be irreversibly destroyed during the fixation process. Although monoclonal anti-Ig Ab frequently worked inadequately, polyclonal anti-Ig Ab were shown to produce reproducible staining results. It thus appeared possible that most cellular Ag might not be irreversibly destroyed but only masked.

EXPERIMENTAL DESIGN

Although some Ag may be retrieved under appropriate conditions, there might still be many for which available antigenic epitopes are still too sparse to be visualized, as observed for a large number of leukocyte differentiation Ag. One reliable approach to resolve this dilemma is the use of a combination of an optimized Ag retrieval system and a powerful immunohistochemical staining protocol introducing a biotin amplification step, in which signal amplification is accomplished by covalent deposition of biotin molecules.

RESULTS

Cryostat and paraffin sections were stained with the avidin-biotin complex technique and, for comparison, with the new maximized immunohistochemical staining protocol, termed the ImmunoMax method. Each step was monitored to establish how effectively it enhanced the overall sensitivity. Although pretreatment with detergent, protease, a chaotropic substance, or microwave heating resulted in only moderately improved immunostaining, the biotinylated tyramine enhancement step proved to be the most efficient one, although the latter is not sufficient for many Ag when used without pretreatment steps. The combination of an Ag retrieval step with the biotinylated tyramine enhancement step resulted in a 100 to 10,000-fold boost in sensitivity without loss of specificity.

CONCLUSIONS

With the ImmunoMax method, defined Ag can be reproducibly detected in formalin-fixed, paraffin-embedded tissues, and the sensitivity of the method is tremendously enhanced. Moreover, it also allows many previously unreactive or unsatisfactorily reactive Ag to be detected, as shown here for IgD, IgM, and CD7 with the use of mAb.

Immunogold labeling of oncogenic and tumor related proteins

Immunogold labeling electron microscopy technique has been used to study the ultrastructural localization of oncogenic proteins: Mos, Met, Ski, and the tumor-associated protein, Muc1, as well as their relationship with other tumor-related proteins. By pre- and postembedding immunogold labeling electron microscopy techniques, we showed that the Mos protein pp39mos colocalized with microtubule bundles, suggesting that microtubulin or microtubule-associated protein(s) may be the substrate of Mos. Met protein was labeled at the microvilli of the lumen that are formed in cultured T47D cells, implying its potential involvement in lumen formation. Ski localization experiments revealed a unique globular structure "Ski body" that is present inside the nucleus of interphase chicken embryo fibroblast infected with Ski cDNA FB29 and FB2-29. Ski bodies were also found scattered in the cytoplasm of metaphase FB29 and FB2-29 Ski expressing chicken embryo fibroblasts. In T47D cells, tumor-associated protein Muc1 was associated with both the plasma membrane and the membranes of secretory vesicles in the cytoplasm. In MUC1 infected NIH3T3 cells, however, labeling showed that in addition to the plasma membrane and the membranes of secretory vesicles, some Muc1 gold spheres were seen inside the secretory vesicles, suggesting that the subcellular localization of the protein may vary in different cell types.

[Comparative study of umbilical artery Doppler velocimetry, antenatal fetal heart rate monitoring and umbilical artery blood-gas analysis in the prediction of neonatal outcome]

One hundred and fifteen term pregnancies (62 normal pregnancies, 53 high risk pregnancies) were observed by umbilical artery Doppler velocimetry (UmA S/D ratio) and antenatal fetal heart rate monitoring (NST), and 37 of them were also observed by umbilical artery blood-gas analysis at birth. We compared the effects of these three methods to predict the neonatal outcome. The standards of the neonatal poor outcome were 5-min Apgar score < or = 7 and/or a birth weight < 2500g (SGA). The results were: (1) The neonatal poor outcome were more frequently observed in the abnormal UmA S/D ratio (> or = 3.0) group and in the UmA pH < or = 7.2 group (P < 0.005, P < 0.025, respectively), but there was no significant difference between the NST reactive or nonreactive groups (P > 0.05); (2) The neonatal acidosis at birth was also associated with the abnormal UmA S/D ratio (> or = 3.0); (3) The sensitivities of UmA S/D ratio, UmA pH, NST to predict the 5-min Apgar score < or = 7 were 60.0%, 60.0%, 20.0% respectively; the specificities 84.6%, 81.3%, 81.8% respectively. And their sensitivies to predict SGA were 100.0%, 100.0%, 40.0% respectively; the specificities 86.4%, 80.0%, 82.7% respectively. Our data show that UmA S/D ratio and UmA pH are better than NST in the prediction of neonatal outcome, and the abnormal UmA S/D ratio is closely associated with neonatal acidosis at birth.

Isolation and expression analysis of tyro3, a murine growth factor receptor tyrosine kinase preferentially expressed in adult brain

Growth factors and their receptors function in the nervous system to induce proliferation and differentiation of neuronal precursor cells and to support survival of mature neurons. We have isolated a murine growth factor receptor tyrosine kinase using an anti-phosphotyrosine antibody screening procedure and studied the pattern of expression. The deduced amino acid sequence of the kinase has all the characteristics of a growth factor receptor and consists of a putative extracellular domain, a transmembrane domain, and a tyrosine kinase domain. Sequence comparison with known receptor tyrosine kinases indicated that the murine kinase is a mouse homolog of tyro3. tyro3 belongs to the Axl/Ufo growth factor receptor family. In the putative extracellular domain, there are two Ig-like domains and two fibronectin type III repeats which are conserved in other members of the Axl/Ufo family receptors. Northern blot hybridization analysis showed that tyro3 is expressed at high levels in the brain of adult mice, although considerable expression was also observed in the testis. In situ hybridization analysis revealed that high levels of tyro3 are expressed in the cerebral cortex, the lateral septum, the hippocampus, the olfactory bulb, and in the cerebellum. The highest levels of tyro3 expression in the brain are associated with neurons. The preferential expression of tyro3 in specific regions of the adult mouse brain suggests that tyro3 may function as a novel neurotrophic factor receptor.

[The analysis of the causes and changes in maternal mortality in 42 years]

The causes and change of maternal death in this hospital from 1949 to 1990 was analyzed. The average maternal mortality of 42 years was 150.22/10(5) livebirths. The 42 years was divided into four periods which were 1949-1960, 1960-1970, 1971-1980 and 1981-1990. The results showed that the maternal mortality rate lowered from 365.31/10(5) livebirths in first period to 43.67/10(5) livebirths in the 4th period. The difference was markedly significant P < 0.01. The direct obstetric causes of maternal deaths in these periods were 30.00%, 23.81%, 25.00% and 55.56% respectively and increased in the 4th period. Obstetric hemorrhage (55.71%) pregnancy induced hypertension (31.43%) and preperal infection (11.43%) were the three main causes of maternal deaths in direct obstetric causes. Cardiac diseases (40.00%) was the leading cause in indirect causes.

Further observations on the human maximum safe dietary selenium intake in a seleniferous area of China

This report is a summarization of preliminary results from a study of dietary Se intake in a seleniferous area in order to determine safe levels. All patients have symptoms of toxicity: broken hair strands or various levels of nail damage. Finger-nail signs were the first symptoms used for diagnosis of selenosis in this work. Based upon the lowest blood-Se level of five subjects with persistent overt finger-nail signs of selenosis, it was found in 1986 that the individual marginal toxic blood Se level (LOAEL) and the corresponding Se intake were 1054 micrograms/L and 910 micrograms/d, respectively. To re-examine the clinical signs and blood Se levels of the five individuals and to see how the two are correlated, a study was conducted in July 1992 at the same location in the seleniferous area. The results showed that along with the absence of clinical signs, the average blood Se level had decreased from 1346 to 968 micrograms/L. The corresponding safe Se intake per day would be 819 +/- 126 micrograms (15 micrograms/kg B.W. or approximately 800 micrograms per day, which is suggested as the mean No Adverse Effect Level (NOAEL), and the lower limit of the 95% confidence interval, 600 micrograms per day would approximately the maximum individual safe Se intake. For safety, 400 micrograms is again proposed as the Maximum Safe Daily Dietary Se Intake. Problems inherent in this estimation have been discussed.

A serosurvey using enzyme-linked immunosorbent assay for antibodies against poultry pathogens in ostriches (Struthio camelus) from Zimbabwe

Horseradish peroxidase-conjugated goat anti-ostrich IgG was raised and used in commercial enzyme-linked immunosorbent assay kits to detect antibodies reactive with 11 poultry pathogens in sera from 149 ostriches from nine farms around Zimbabwe. Antibodies were detected to turkey rhinotracheitis virus (99%), Newcastle disease virus (23%), avian reovirus (19%), infectious bursal disease virus (15%), avian encephalomyelitis virus (15%), Mycoplasma gallisepticum and/or M. synoviae (11%), reticuloendotheliosis virus (10%), Salmonella enteritidis (8%), avian leukosis virus (3%), infectious bronchitis virus (2%), and Pasteurella multocida (< 1%). Although evidence of prior infection with turkey rhinotracheitis and newcastle disease virus was present on all farms tested, there was marked variation between farms in the prevalence of exposure to other poultry pathogens.

Quantitation of prostate-specific acid phosphatase in prostate cancer: reproducibility and correlation with subjective grade

In this study, we quantitatively evaluated the intensity and extent of prostate-specific acid phosphatase in immunocytochemically stained prostate carcinoma tissue sections by using a dual-wave-length-based image processing technique. Tissue sections were doubly stained in a standard way, i.e., prostate-specific acid phosphatase was immunocytochemically labeled by peroxidase-antiperoxidase (PAP) technique using diaminobenezidene (DAB) as the substrate and hematoxylin as a nuclear counterstain. Statistical analysis in this study indicated that the quantitative measures of the prostate-specific acid phosphatase staining (PAP-DAB) are reproducible. We found that the quantitative intensity was generally proportional to the subjective intensity (graded as 1 to 4+) of PAP-DAB. Although the quantitative extent measurements compared with the subjective estimates of the percentage of tumor showing staining with PAP-DAB had a similar tendency, there were significant overlaps between extent of tumor staining falling in the mid-ranges. Because subjective grading of immunocytochemical prostate-specific acid phosphatase has been thought to be a useful marker of tumor differentiation in patients with prostate carcinoma, we also evaluated the relationship of the quantitative measures of PAP-DAB staining to other predictors of patient outcome, including histologic grades (Gleason score and MD Anderson grading scheme) and clinical stage. We confirmed that quantitative intensity and extent of PAP-DAB staining were independent of histologic grades and stage, just as the subjective measures of intensity and extent were found to be. Possible explanations of this lack of correlation are discussed.

Direct observation of the effect of autoreceptors on stimulated release of catecholamines from adrenal cells

The direct effect of alpha 2-autoreceptors was studied by measuring the effects of piperoxan, an alpha 2-autoreceptor antagonist, and clonidine, an agonist on catecholamine exocytosis, from single bovine chromaffin cells in culture. Catecholamine release was elicited by stimulation with 100 microM nicotine and was monitored electrochemically with a carbon-fiber microelectrode placed adjacent to the cell. These electrodes allowed the number of exocytotic release events to be monitored and reported as total charge for release following a specific stimulus. Repeated stimulation with 100 microM nicotine showed that total release caused by the second exposure to nicotine was 32% of the first, and release caused by the third exposure to nicotine was 80% of the second. Total release of catecholamine increased significantly after application of 20 microM piperoxan relative to a control application of balanced salt solution. Application of 20 microM piperoxan alone did not cause release. After the cells were incubated in culture medium containing 20 microM clonidine, a significant decrease in nicotine-stimulated catecholamine release was observed. These results confirm that there are autoreceptors on chromaffin cells and, when relatively high levels of catecholamine are released, the catecholamine stimulates the alpha 2-autoreceptors, which inhibits subsequent release through a negative feedback mechanism. In addition to piperoxan, the sympathomimetic drug amphetamine also increases quantal release after application of nicotine. Amphetamine increases the extracellular concentration of catecholamine, and these data appear to indicate that at least part of the pharmacology of amphetamine might involve blocking catecholamine autoreceptors.

Isolation and characterization of Bsk, a growth factor receptor-like tyrosine kinase associated with the limbic system

Neuronal degeneration has been shown to be involved in various neurological disorders. Growth/trophic factors and their receptors are known to be important for the regeneration and survival of neurons. We report here the molecular cloning of a receptor-like protein tyrosine kinase, bsk, (for brain specific kinase). Bsk is highly related to the eph/elk receptor-like kinase family members. Northern blot analysis shows that it is expressed specifically in the brain, with no expression detected in adult heart, spleen, lung, liver, skeletal muscle, and kidney. In situ hybridization analysis of adult mouse brain sections indicates that bsk is expressed at high levels in the hippocampus, tenia tecta, indusium griseum, and the piriform cortex, major components of the limbic system that are important for learning and memory. In addition, elevated levels of expression are found in other areas of the limbic system such as the amygdala, medial septum, and nucleus of the diagonal band, and in the olfactory bulb, which has close connections to the limbic system. The highest level of expression is found in the CA3 region of the hippocampus and the pyramidal cell layer of the piriform cortex. In 16.5 day mouse embryos, bsk is expressed predominantly in the primordial cortex of the telencephalon. An antibody against a C-terminal peptide of bsk recognized a 105 kD protein in the 16.5 day embryonic head extract. Our analysis shows that bsk is a growth factor receptor-like protein tyrosine kinase and that its greatest expression in the adult brain is associated with components of the limbic system.

[A study on the transcriptional expression of oncogenes in human primary brain tumors]

The c-myc, L-myc, N-myc, Ha-ras, c-fos, and v-erbB oncogenes were used as probes to detect the total RNA of 5 cases of normal human brain tissues and 29 cases of brain tumor tissues by RNA dot hybridization analysis. The results showed that the increasing expressions of cerbB and c-fos were the highest, being 88.2% and 82.4%, respectively, the next was c-myc with an increased expression of 46.1%; the increasing expressions of L-myc (29.3%) and N-myc (31.6%) were observed in a few samples only. There was no significant difference of Ha-ras gene expression between normal brain and brain tumor. In addition, we observed the increasing expression of more than one oncogene in one sample. These results suggest that c-erbB and c-fos oncogenes may play an important role in the pathogenesis of human primary brain tumors, and that multiple genetic changes are implicated in genesis of human brain tumors.

Etiological investigation of acute post-transfusion non-A, non-B hepatitis in China

The etiology of acute post-transfusion hepatitis (PTH) non-A, non-B (NANB) in China was investigated with the combination of advanced techniques, including a second generation of enzyme immunoassay for detection of the antibodies to hepatitis C virus (anti-HCV), a reverse transcription and nested polymerase chain reaction (RT-nPCR) for HCV RNA, and a PCR for hepatitis B virus DNA. Of the 57 patients who were diagnosed as acute PTH-NANB, 46 (80.7%) were positive for anti-HCV and 41 (71.9%) had HCV RNA. Combining together, 53 (93.0%) were seropositive for anti-HCV and/or HCV RNA. Surprisingly, 18 of these with HCV markers were also positive for HBV DNA, although they were negative for HBsAg, suggesting that a portion of the patients with acute PTH NANB were coinfected by both HCV and HBV. In addition, 4 (7%) of the patients with acute PTH-NANB had no detectable HCV and HBV markers with the use of the above-mentioned techniques. These results indicate that etiologic agents(s) other than HCV and HBV may also cause acute PTH-NANB or that the current techniques may still not be sensitive enough to detect trace levels of HCV and HBV markers.

pp39mos is associated with p34cdc2 kinase in c-mosxe-transformed NIH 3T3 cells

We investigated the possible interactions between pp39mos and p34cdc2 kinase in NIH 3T3 cells transformed by c-mosxe. pp39mos is coprecipitated with p34cdc2 when using either anti-PSTAIR antibody or p13suc1-Sepharose beads. Likewise, p34cdc2 is coprecipitated with pp39mos when using anti-mos antibody. However, pp39mos was not present in histone H1 kinase-active p34cdc2 complexes precipitated with anti-p34cdc2 C-terminal peptide antibody even during metaphase of the cell cycle. The molar ratio of p34 to pp39mos in the p13suc1 complex is approximately 2:1. Consistent with the tight association between pp39mos and tubulin, tubulin was also present in equivalent amounts with pp39mos and p34 in the p13suc1 complex. This pp39mos-p34cdc2-tubulin complex may be important in transformation by the mos oncogene.

Correlation between the prevalence of serum HBV DNA and immunoserologic HBV markers in the subjects with or without hepatitis

The prevalence of serum HBV DNA, detected by polymerase chain reaction, and that of immunoserologic HBV markers (HBsAg, HBeAg, anti-HBs, and anti-HBc), determined by immunoassays, were compared among three groups of subjects: (A) chronic active hepatitis B patients, (B) chronic asymptomatic HBV carriers, and (C) normal individuals. Except five of the normal individuals, all of the subjects are positive for anti-HBc while some of them were also positive for other immunoserologic HBV markers, such as anti-HBs, HBsAg, and HBeAg. Serum HBV DNA were detected in 81% in group A, 52% in group B, and 20% in group C. In both group A and B, serum HBV DNA were detected in all the subjects with anti-HBc+/HBsAg+/HBeAg+. However, the percentage of seropositive HBV DNA in the subjects with anti-HBc+/HBsAg+ in Group A was much higher than that in Group B. Interestingly, the percent of serum HBV DNA+ in the individuals with anti-HBc+ only was markedly higher than that in the subjects with anti-HBc+/anti-HBs+ in both Group A and C, suggesting that anti-HBs may play a role in the inhibition of HBV replication and clearance of HBV virion from blood. Above serological profiles will provide important information concerning the significance of serum HBV DNA detection in judgement of HBV replication in the individuals with or without HBV infection. Cautions should be taken to clarify those so called normal individuals who have no symptoms of hepatitis B, no HBsAg in the sera and normal transaminase, but have HBV replication in their bodies.

Quantitative peroxidase-antiperoxidase complex-substrate mass determination in tissue sections by a dual wavelength method

The aim of this study was to develop a method of quantitating prostate-specific acid phosphatase (PSAP) in histologic sections of prostate tumor tissue labeled with the peroxidase-antiperoxidase (PAP) complex technique using diaminobenzidine (DAB) as a substrate. Studies of PAP-DAB- and hematoxylin-stained prostate tissue sections were performed with a black-and-white, computerized microscope image system. The mass of brown reaction product generated in PAP-DAB staining was the indicator of PSAP intensity. The mass of brown reaction product was determined by using a dual wavelength method in which two 10-nm bandpass filters, peaked at 450 and 510 nm in wavelength, were used. The wavelength-dependent ratio of mass absorptivity of PAP-DAB stain (brown product) and that of hematoxylin (blue product) were estimated at wavelengths of 450 and 510 nm by using slides stained with only PAP-DAB or hematoxylin. The accuracy of the mass measurements, investigated by relating the measurement to the true mass of the brown PAP-DAB product, is reported. There was no significant difference between the measurements at magnifications of 10x, 20x, 40x or 60x in the reproducibility investigation. The PSAP stain intensity was quantitatively determined by the difference of the PAP-DAB stain mass per pixel between the tumor and normal cell region. The relationship between the objective measurement and the conventional subjective grades is presented.