[Studies on the relationship between purified alpha class glutathione S-transferase (GST-alpha) and hepatocellular damage]

Using our ELISA kit for GST-alpha, we tested the serum GST-alpha levels of patients with hepatitis A, acute hepatitis B (HB), chronic active HB, chronic persistent HB and liver cirrhosis. Serum GST-alpha levels in all these groups of patients were significantly higher than those in the controls (P < 0.01). Serum GST-alpha levels was closely (P < 0.01) correlated with serum alanine transaminase (ALT) levels in various groups of patients except chronic persistant HB. The combined application of the two markers, GST-alpha and ALT, raised the sensitivity of detection for liver diseases. In detection of chronic persistent HB patients, the GST-alpha marker was more sensitive than ALT (P < 0.01). The follow-up data of GST-alpha and ALT markers in serum showed that the GST-alpha level could reflect the clinical progression of liver disease more exactly as observed in 79 liver cancer patients in then GST-alpha and ALT positive rate were 81% and 61% respectively (P < 0.01). In 30 persons with positive HBsAg, the positive rates of GST-alpha and ALT were 70% and 37%, respectively. These results indicated that, (1) the detection of GST-alpha combined with ALT was capable of increasing the sensitivity for recognizing hepatocellular damage; (2) the elevation of serum GST-alpha level mainly resulted from the increased expression of GST-alpha in liver cells during hepatocarcinogenesis, thus, the GST-alpha is thought to be a tumor marker for liver cancer; (3) GST-alpha measurement offers advantage over ALT for the detection of minor degree of hepatocellular damages. GST-alpha may act as an early, sensitive and specific enzyme marker.

Image-scaling problem in the optical fractional Fourier transform

The significance of scale factors and cascade of optical fractional Fourier transform is emphasized. Exact and cascadable fractional Fourier transforms in practical applications mandate that the image scale be the reciprocal of the scale of the input plane controlled by the optical setup. The practical setup of the optical fractional Fourier transform must be without any quadratic phase term at the spectrum plane.

Actin Purified from Maize Pollen Functions in Living Plant Cells

A vast array of actin binding proteins (ABPs), together with intracellular signaling molecules, modulates the spatiotemporal distribution of actin filaments in eukaryotic cells. To investigate the complex regulation of actin organization in plant cells, we designed experiments to reconstitute actin-ABP interactions in vitro with purified components. Because vertebrate skeletal [alpha]-actin has distinct and unpredictable binding affinity for nonvertebrate ABPs, it is essential that these in vitro studies be performed with purified plant actin. Here, we report the development of a new method for isolating functional actin from maize pollen. The addition of large amounts of recombinant profilin to pollen extracts facilitated the depolymerization of actin filaments and the formation of a profilin-actin complex. The profilin-actin complex was then isolated by affinity chromatography on poly-L-proline-Sepharose, and actin was selectively eluted with a salt wash. Pollen actin was further purified by one cycle of polymerization and depolymerization. The recovery of functional actin by this rapid and convenient procedure was substantial; the average yield was 6 mg of actin from 10 g of pollen. We undertook an initial physicochemical characterization of this native pollen actin. Under physiological conditions, pollen actin polymerized with kinetics similar in quality to those for vertebrate [alpha]-actin and had a critical concentration for assembly of 0.6 [mu]M. Moreover, pollen actin interacted specifically and in a characteristic fashion with several ABPs. Tradescantia cells were microinjected and used as an experimental system to study the behavior of pollen actin in vivo. We demonstrated that purified pollen actin ameliorated the effects of injecting excess profilin into live stamen hair cells.

[Partial deletion of mitochondrial DNA in mitochondrial encephalomyopathies]

OBJECTIVE

To characterize the deletions of mitochondrial DNA (mtDNA) in Chinese patients with Kearns-Sayre syndrome (KSS) and chronic progressive external ophthalmolegia (CPEO) and identify deletion mutations of mtDNA be the etiology of these diseases.

METHODS

Patients and preparation of total DNA: Two patients with KSS and two with CPEO and ten with other mitochondrial myopathies or encephalomyopathies were determined by histological and biochemical assays. Total DNA was isolated from 100 mg to 150 mg of frozen muscle obtained by biopsy using the methods described by Zeviani et al. (1988). Preparation of mtDNA probes: MtDNA were isolated and purified according to Palva's method (1985). The mtDNA was linearized by digestion with the restriction endonuclease Pvu II and separated by electrophoresis through low melting agarose gel. The 16.5 kb DNA band was recovered from the gel and labeled with alpha-p32 dCTP by random primer labeling. Southern blot analysis: Portions of five micrograms total DNA obtained from the patients and controls were digested with Pvu II, EcoR I, Hind III And Xba I respectively. The digested DNA was separated by agarose gel electrophoresis and transferred to nitrocellulose membrane and then hybridized with P32 labeled mtDNA as previously described (Zhang, 1991).

RESULTS

A large-scale deletions of mtDNA were identified in two patients with KSS and two patients with CEPO. The deletions ranged in size from 2.4 kb to 5.5 kb. The proportion of mutated mtDNA in each patients ranged from 54.6% to 84.6% of total mtDNA. No detectable deletions were found in mtDNA of ten patients with other mitochondrial myopathies or encepholomyopathies and normal controls.

CONCLUSIONS

Deletions of mtDNA were found in all KSS and CEPO patients detected. These results supported The view point of the deletions are important causes of physical defect in KSS and CEPO.

[Application of rigid bronchoscopy in airway management after lobectomy of lung]

OBJECTIVE

Application of rigid bronchoscopy in airway management after lobectomy of lung was recommended, and its significance was discussed.

METHODS

Bronchoscopies were performed in three patients scheduled for lobectomy of lung undergoing epidural plus general anesthesia. Each patient was examined two times. The first examination was done after anesthetic induction and intubation. The second was given at the end of operation.

RESULTS

Rigid bronchoscopy under general anesthesia could clearly show the inner structures of trachea, bronchi and location of carcinoma. Under direct version, the secretion and sludged blood in the trachea and bronchi after lobectomy could be scavenged.

CONCLUSION

It was suggested that with the use of bronchoscopy the complications including postoperative atelectasis and bronchial-pleural fistulization could be reduced.

The effect of a shear force on the cell shedding rate of the corneal epithelium

PURPOSE

During blinking the lids apply a shear force to the corneal epithelium. The aim of this study was to determine if a shear force applied to the epithelial surface increases the rate at which cells shed.

METHODS

The shedding rate was studied in perfused whole rabbit eyes, and the effect of a shear force examined by exposing the corneas to a stirred solution. Control corneas were exposed to a static solution. The shedding rate and size of shed cells were measured, and the number of terminally differentiated cells on the corneal surface determined after 6 h of perfusion using ethidium bromide.

RESULTS

Compared with controls, the shear force increased the cell shedding rate from the corneal surface significantly (p < 0.01, paired t-test). The increase was due to small cells with a longest dimension less than 25 microm. The number of terminally differentiated cells on the epithelial surface did not increase.

CONCLUSION

Because of the decrease in size, and the change in appearance of shedding cells, it is proposed that the increase in cell shedding rate was due to an increase in the number of apoptotic cells, and not to an increase in terminally differentiated cells. It is suggested that in the human eye, under adverse conditions, shear forces due to blinking may play a role in creating apoptotic cells.

Pulmonary leiomyosarcoma

Three cases of pulmonary leiomyosarcoma were presented. The characteristic clinical features were described with review of literature. In comparison with bronchogenic carcinoma, the leiomyosarcoma has some characteristics: 1) On chest X-ray, it usually appears as a sharply demarcated, even density round mass, growing rapidly within the lung, it unusually accompanies with hilar or mediastinal lymph node metastasis; 2) The preoperative cytological or pathological diagnosis is difficult either by sputum smear or by bronchoscopic biopsy or by fine needle percutaneous aspiration biopsy; 3) Pathological differential diagnosis of leiomyosarcoma of lung from anaplastic lung cancer is difficult. In conclusion, the primary pulmonary leiomyosarcoma is a rare malignant tumor, detecting the present illness seriously, paying attention to the chest X-ray films characterize, early surgical resection is the only way to get diagnosis and effective treatment method.

[Discordance of increase in stress proteins in right and left myocardium of perfused isolated rat heart]

Discordance of functional and structural changes in right and left myocardium has been considerably discovered in various physiologically stimulated hearts and patients with cardiopathy, but the reasons for that have not yet been known. In the present study, induction of stress proteins, i.e. heat shock proteins, was analyzed and compared between the left and right myocardium of normoxic and hypoxic perfused isolated rat hearts by the methods of two dimensional electrophoresis and silver staining. The results showed that three Hsp70 isoforms (molecular weight 68, 70 and 72 k mu) with pI ranging from 6.3 to 7.3 were increased distinctly in both right and left myocardium under the conditions of perfusion as mentioned above. Moreover, the amount of the stress proteins increased in the right myocardiums was higher than that in the left myocardium, indicating that the response of right heart to the stimulus of hypoxic or normoxic perfusions is different from the reaction of left heart, and the extent of protection in left and right heart by stress proteins is unlike. In addition, the activity of catalase was found to be obviously declined in all perfused isolated hearts. It was suggested that the different increase in stress proteins may be due to different structure and status of right and left ventricle and the oxidative stress may be one of the important reasons to induce or enhance the synthesis of stress proteins.

[Effect of combination of herbimycin A, an inhibitor of tyrosine kinase, and chemotherapeutic agents on apoptosis of K562 cells]

OBJECTIVE

To explore the anti-apoptotic mechanism and the apoptosis-inducing method in chronic myeloid leukemia (CML) cells.

METHODS

K562 cell line was used to observe the effect of combination of herbimycin A (HMA), a tyrosine kinase inhibitor, and chemotherapeutic agents on the induction of apoptosis.

RESULTS

HMA or chemotherapeutic agents could inhibit the proliferation but not significantly induce apoptosis of K562 cells. However, HMA significantly enhanced apoptosis when combined with chemotherapeutic agents. Addition of sulfhydryl compound to the cultures to conjugate HMA completely abrogated this enhancing effect on K562 cells.

CONCLUSION

HMA increases the sensitivity of CML cells to chemotherapeutic agents by inactivating tyrosine kinase activity. It is promising that combination of HMA with conventional chemotherapeutic drugs in the treatment of CML.

[Granulocyte-macrophage colony-stimulating factor and erythropoietin induce tyrosine phosphorylation and activation of JAK2]

OBJECTIVE

In order to identify the tyrosine kinase (s) that may associate with cell proliferation.

METHODS

GM-CSF/Epo responsive cell UT-7 and Epo responsive cell UT-7/Epo were used for study of tyrosine phosphorylation.

RESULTS

The addition of GM CSF and/or Epo to the responsive cells induced rapid tyrosine phosphorylations of 145000, 130000, 80000 and 40000 cellular proteins. The tyrosine phosphorylated 130000 protein was identified as JAK2, a non receptor tyrosine kinase. GM CSF and Epo also activated its tyrosine kinase activity. Tyrosine phosphorylation and activation of JAK2 only occurred in GM-CSF and/or Epo-responsive cells.

CONCLUSION

JAK2 signal transduction pathway may play an important role in regulating the proliferation of hematopoietic cells induced by GM-CSF and Epo.

Adherence of Pseudomonas aeruginosa to shed rabbit corneal epithelial cells after overnight wear of contact lenses

PURPOSE

Previous studies have shown that contact lens oxygen transmissibility correlates with binding of Pseudomonas aeruginosa to the rabbit cornea after overnight lens wear. Studies of human lens wear stratified by oxygen transmissibility will be required to validate these animal results. In humans, bacterial binding to shed cells obtained through corneal irrigation cytology may provide an indirect measure of in vitro binding. The purpose of this study was to establish the relationship between binding to shed cells and to the residual corneal surface in an animal model of lens wear prior to initiation of human studies.

METHODS

The test contact lenses used were: rigid lens A (Dk/L = 10 x 10(-9) [cm/ sec][mL O2/mL mmHg]); rigid lens B (Dk/L = 97); soft lens A (Dk/L = 9); soft lens B (Dk/L = 20); and, soft lens C (Dk/L = 39). There were six rabbits in each group, except for the soft lens C group, which had seven rabbits. After overnight lens wear, the corneal surface was irrigated with a corneal irrigation chamber to collect surface cells before exposure to a bacterial suspension (1 x 10(7) CFU/mL) for 30 minutes. The number of bacteria adherent to the residual corneal surface was then assessed by CFU determination. Cells collected from the corneal surface (9 mL) were incubated with 1 mL bacterial suspension containing 10(8) (CFU/mL) for 30 minutes. The number of bacteria adherent to shed cells was assessed by staining with acridine orange and direct counting by epifluorescence microscopy.

RESULTS

The differences in the number of bacteria adhering to shed epithelial cells between the treated and the control eyes were 2.90 +/- 1.20 and 0.23 +/- 0.41 for rigid lenses A and B, respectively, and 5.97 +/- 1.54, 3.67 +/- 2.32, and 0.90 +/- 1.45 (bacterial/cell) for soft lenses A, B, and C, respectively. Overnight contact lens wear induced a significant increase in bacterial binding to shed corneal epithelial cells for rigid lens A and for soft lenses A and B. There were significant differences among lens groups (P = 0.00017, ANOVA), with significant differences between rigid lenses A and B, soft lenses A and C, and soft lenses B and C. The binding of bacteria to shed cells was significantly correlated with the binding of bacteria to the residual corneal surface, both confirming and extending previous results (R = 0.78, P < 0.001).

CONCLUSION

These results demonstrate a positive correlation between P. aeruginosa adherence to shed corneal cells and to the residual corneal surface in the rabbit eye following contact lens wear. In light of the results from prior animal studies, examination of the behavior of P. aeruginosa binding to exfoliated cells appears to be a promising and valid method for future assessment of similar lens-induced increases in bacterial binding in prospective human clinical studies.

[Preparation method of foamed aerosol for use in vagina]

The extraction of medicinal materials, compatibility of liquor and prescription of emulsion for use in vagina were observed. The result shows that through compound extraction, removal of tannic materials, decolorization and water precipitation, with propylene glycol and ethylene glycol as latent solvent and using lactic acid to adjust to pH4.5, a clarified solution can be obtained, and then with the help of Tween-spans emulisifying agent and propellant the stable emulsion is formed.

Huperzine A, a novel promising acetylcholinesterase inhibitor

The effects of huperzine A on memory impairments induced by scopolamine were evaluated using a radial maze task and inhibition of cholinesterase in vitro compared with the effects of E2020 and tacrine. Scopolamine (0.2 mg kg-1) significantly impaired spatial memory in rats. Huperzine A (0.1-0.4 mg kg-1, p.o.), E2020 (0.5-1.0 mg kg-1, p.o.) and tacrine (1.0-2.0 mg kg-1, p.o.) could reverse these scopolamine-induced memory deficits. The ratios of huperzine A, E2020 and tacrine for butyrylcholinesterase:acetylcholinesterase determined by a colourimetric method were 884.57, 489.05, and 0.80, respectively. The results demonstrated that huperzine A was the most selective acetylcholinterase inhibitor, and improved the working memory deficit induced by scopolamine significantly better than did E2020 or tacrine, suggesting it may be a promising agent for clinical therapy of cognitive impairment in patients with Alzheimer's Disease.

[Effect of leaf picking on the output of radix Astragali seu Hedysari]

Based on an orthogonal design, the experiments have shown that proportion and time of leaf picking are the major factors to influence the thickness and output of Radix Astragali seu Hedysari. If the proportion is extended and the time is delayed, both the thickness and output of the roots will be reduced accordingly. The output will not change much if the time is set on around June 15 each year and the proportion is taken 1 out of 3.

The cell shedding rate of the corneal epithelium--a comparison of collection methods

PURPOSE

To determine the spontaneous shedding rate of cells from the rabbit corneal epithelium using different harvesting methods.

METHODS

Cells were collected from the rabbit corneal epithelium using two in vitro methods and three in vivo methods. Cells were counted and the shedding rate calculated after adjustment for the collection time.

RESULTS

The shedding rates obtained from the in vitro methods were (cells/min/cornea, mean +/- SE): 78.0 +/- 9.4 (corneal superfusion), and 5.4 +/- 1.3 (whole-eye perfusion). For the in vivo corneas, the shedding rates were: 10.0 +/- 2.3 (corneal superfusion), 8.1 +/- 0.4 (corneal immersion), and 14.5 +/- 1.5 (corneal irrigation). In vitro corneal superfusion was significantly different from the other four methods (P < 0.01).

CONCLUSIONS

The results suggest that the spontaneous cell shedding rate of the in vivo rabbit corneal epithelium is 5 to 15 cells/min/cornea. This is much lower than estimates of about 100 cells/min/cornea based upon in vitro corneal superfusion. One explanation of this slow shedding rate is that factors which were absent during our collection methods (such as blinking) would normally increase shedding. Another possibility is that cells in the corneal epithelium may have a much longer life span than previously reported; rather than a few days, the epithelium could take several months to completely replace all cells. Whatever the explanation, the measured spontaneous shedding rate does not complement the reported production rate of new cells. It is necessary to revise our understanding of the kinetics of epithelial homeostasis.

Pulmonary leiomyosarcoma--report of three cases

Three cases of pulmonary leiomyosarcoma were presented. The characteristic clinical features were described with review of literature. In comparison with bronchogenic carcinoma, the leiomyosarcoma has some characteristics: 1) On chest X-ray, it usually appears as a sharply demarcated, even density round mass, growing rapidly within the lung, it rarely accompanies with hilar or mediastinal lymph node metastasis. 2) The preoperative cytological or pathological diagnosis is difficult either by sputum smear or by bronchoscopic biopsy or by fine needle percutaneous aspiration biopsy. 3) Pathological differential diagnosis of leiomyosarcoma of lung from anaplastic lung cancer is difficult. In conclusion, the primary pulmonary leiomyosarcoma is a rare malignant tumor, detecting the present illness seriously, paying attention to the chest X-ray films characterize, early surgical resection is the only way to get diagnosis and effective treatment method.

Leptin is a metabolic signal to the reproductive system

Leptin, a newly-discovered hormonal product of the obese (ob) gene, is expressed by adipocytes and thought to play a role in the regulation of food intake and metabolism. We tested the hypothesis that leptin signals metabolic information to the reproductive system by examining its effects on the reproductive system of ob/ob mice, which have a congenital deficiency in leptin and are infertile. We treated pair-fed males and females with leptin (50 microg twice daily, ip) or vehicle (n=10/group) for 14 days, after which the animals were bled and killed. Leptin-treated females had significantly elevated serum levels of LH, increased ovarian and uterine weights, and stimulated aspects of ovarian and uterine histology compared to controls. Leptin-treated males had significantly elevated serum levels of FSH, increased testicular and seminal vesicle weights, greater seminal vesicle epithelial cell height, and elevated sperm counts compared to controls. These results demonstrate that leptin stimulates the reproductive endocrine system in both sexes of ob/ob mice and suggest that leptin may serve as a permissive signal to the reproductive system of normal animals.

Apoptosis in the corneal epithelium

PURPOSE

To determine the viability of corneal surface cells and to determine whether apoptosis is present in the corneal epithelium of the rabbit.

METHODS

The viability of epithelial surface cells was examined using a calcein-ethidium assay. In this two-color fluorescence assay, viable cells fluoresce green, and the nuclei of nonviable cells fluoresce red. The number of nonviable cells on the normal corneal epithelial surface was quantified. Surface and shed cells also were examined from shear-stressed corneas. The TUNEL technique (TdT-mediated dUTP nick-end labeling) was used to detect DNA fragmentation characteristic of apoptotic cells.

RESULTS

The calcein-ethidium viability assay revealed that the normal epithelial surface is composed mainly of viable cells, with nonviable cells making up a small percentage of the whole. There was an increase in the density of nonviable cells from the periphery of the epithelial surface to the center, In flatmounts of the cornea, TUNEL labeling demonstrated that a small percentage of surface cells exhibited DNA fragmentation, whereas cross-sections revealed that DNA-fragmented cells were found exclusively on the epithelial surface. Epithelial cells from shear-stressed corneas showed an increased number of apoptotic cells.

CONCLUSIONS

The normal epithelial surface consists mainly of viable cells, with only a small percentage of nonviable cells and apoptotic cells. The results suggest that nonviable epithelial cells are shed after terminal differentiation, whereas viable cells can be shed by classical apoptosis with the formation of blebs. Thus, there appears to be more than one mechanism for removal of cells from the corneal surface.

[Prevention of endotoxic shock in rats with hepatic stimulating substance]

In order to understand the mechanism of prevention of endotoxic shock and evaluate the pathological changes taking place, an animal model of endotoxic shock was established by intravenous injection of endotoxin into rats, which were then treated with a hepatic stimulating substance, hepatopoietin (HPN). The results were as follows; (1) There was coincidence of low blood pressure and high serum level of tumor necrosis factor (TNF) in the experimental rats. (2) Simultaneous intravenous injection of endotoxin and introperitoneal injection of HPN showed that HPN can prevent the drop of blood pressure, lower the TNF level and ameliorate the tissure injury in lungs and kidneys induced by endotoxin. If HPN was given 15 minutes ofter injection of endotoxin, the drop of blood pressure could not be prevented and the TNF level remained high. It is suggested that TNF is an important mediator for endotoxic shock and treatment of endotoxic shock might be effective, if it is intituted early.

Separate promoters in the human A1 adenosine receptor gene direct the synthesis of distinct messenger RNAs that regulate receptor abundance

There are two types of transcripts for the human A1, adenosine receptor. They are expressed in a tissue-specific manner in human tissues and contain distinct exons. Previously, it had appeared that the two transcripts may have occurred through alternative splicing. The transcript beta has two upstream AUG codons, which in transiently transfected COS-7 cells leads to a reduced level of receptor expression. When genomic sequence including sequences 5' to transcriptional start site, exon 1A, intron 1A, exon 1B, intron 1B, exon 2, and coding sequence was inserted into an expression vector (pCMV5/huA1), the resulting transcripts had the same overall structure as the transcripts present in human tissues. Primer extension and 5' rapid amplification of cDNA ends of mRNA from transfected cells revealed the transcription start sites for these two transcripts occurred in what previously had been termed introns. These results were confirmed with similar analysis of mRNA derived from human tissues. Two nonconsensus putative TATA boxes (TTAAGA and TTTAAA) are located upstream of the transcription start sites for transcripts alpha and beta. When the TATA boxes and their flanking sequences were fused to a firefly luciferase gene containing promoterless vector, both demonstrated strong promoter activity in Chinese hamster ovary cells. Promoter A directs the synthesis of transcript alpha, and promoter B directs the synthesis of transcript beta. Promoter A contains a series of AGG elements between the putative TATA box and the transcription start, which accounts for a major portion of the promoter activity based on deletion and mutation analysis. In general, promoter A is more active than promoter B in transfected cells. The nonconsensus TATA box in promoter B plays a more important role in promoter activity than the TATA box in promoter A. The human A1 adenosine receptor gene appears to use two separate promoters to direct synthesis of distinct transcripts, which can then regulate the relative abundance of A1 adenosine receptor in tissues. We have redefined the human A1 adenosine receptor gene structure based on these new data.

NMR identification of calcineurin B residues affected by binding of a calcineurin A peptide

Triple resonance 3D NMR methods have been used to study the interaction between calcineurin B and a peptide fragment of calcineurin A for which it has high affinity (KD approximately 4 x 10(-7) M). Although calcineurin B aggregates at NMR concentrations of approximately 1 mM, in the presence of a target peptide fragment of calcineurin A it becomes monomeric and yields NMR spectra that are very similar to those reported previously for calcineurin B solubilized by the zwitterionic detergent CHAPS. Changes in chemical shifts between CHAPS- and peptide-solubilized calcineurin B are small which is indicative of no differences in secondary structure. Residues most affected by binding to target peptide are found primarily on the hydrophobic faces of the four helices, present in each of the two globular domains in calcineurin B, and in the loops connecting helices II and III, IV and V, and possibly in the C-terminal 12 residues, which also exhibit a change in mobility.

Human adenosine A1 receptor gene: systematic screening for DNA sequence variation and linkage mapping on chromosome 1q31-32.1 using a silent polymorphism in the coding region

Adenosine is a major inhibitory neuromodulator in the central nervous system. One of the receptors mediating the central effects of adenosine is the adenosine A1 receptor. We performed a systematic mutation scan of the coding region of the adenosine A1 receptor gene to explore its variability in the general population. Investigating 40 unrelated healthy subjects by single-strand conformation analysis no sequence changes of likely functional relevance were observed. We detected, however, a frequent T to G substitution at nucleotide position 716 which constitutes the first variant described in an adenosine receptor gene. It was used for fine scale linkage mapping of the A1 gene. Employing a polymerase-chain-reaction-based restriction assay, we genotyped 7 CEPH families (Centre d'Etude du Polymorphisme Humaine) and mapped the receptor in a gene cluster around the renin gene on chromosome 1q31-32.1. In addition, we utilized the 716T/G polymorphism to demonstrate biallelic expression of the adenosine A1 receptor gene in adult human brain.

Solution structure of calcium-free calmodulin

The three-dimensional structure of calmodulin in the absence of Ca2+ has been determined by three- and four-dimensional heteronuclear NMR experiments, including ROE, isotope-filtering combined with reverse labelling, and measurement of more than 700 three-bond J-couplings. In analogy with the Ca(2+)-ligated state of this protein, it consists of two small globular domains separated by a flexible linker, with no stable, direct contacts between the two domains. In the absence of Ca2+, the four helices in each of the two globular domains form a highly twisted bundle, capped by a short anti-parallel beta-sheet. This arrangement is qualitatively similar to that observed in the crystal structure of the Ca(2+)-free N-terminal domain of troponin C.

A comparison of the effects of the propofol versus midazolam during total intravenous anesthesia for gynecological surgery procedures

The effects of propofol and midazolam as an intravenous anesthetic were compared in 40 ASA I-II patients undergoing gynecological surgery during total intravenous anesthesia (TIVA). They were divided into propofol group (P n = 20) and midazolam group (M n = 20) randomly. The anesthesia was designed for each group respectively. Here, we discuss the experimental method and the results, which indicate that propofol is not only an effective anesthetic but also has more rapid and head-clear recovery properties than midazolam.

[Expression of 12 antibody escape mutants of hepatitis B virus surface antigen gene in mammalian cell by using an Epstein-Barr based vector]

A 900bp DNA fragment of hepatitis B virus surface antigen gene by digesting BamHI and HpaI sites on the open reading frame of HBV DNA on plasmid pEcob6 containing double copes of HBV DNA was cloned into SmaI site on the phagmide vector pBluescribt SK +. From this recombinant vector, 12 hepatitis B virus surface antigen gene mutants were obtained by oligonucleotide-mediated site directed mutagenesis. The expression vector-pMEP4HBS mutants are constructed by sub-cloning all of these mutant fragments of hepatitis B virus surface antigen gene on pBluescritSK+HBSM into BsmHI and KpnI sites on an Epstein-Barr virus based on eukaryotic expression vector-pMEp4. The vector pMEp4HBSMs were transfected to human hepatocellular carcinoma cell line-HepG2 by calcium phosphate mediated transfection, and resistant cell clones were obtained 3 weeks after selecting by hygromycine B. The results of detection of HBsAg excreted by resistant cell clones with monoclonal antibody to HBsAg showed that all antibody escape mutants of HBsAg except mutant 145R, a substitution of arginine for glycine at amino acid 145 position in HBsAg, were positive.

Corneal epithelial fluorescein staining

BACKGROUND

There is some difference of opinion in the literature about the nature of fluorescein staining of the epithelial surface. Most authors support the view that fluorescein staining is due to drop out of cells and pooling of fluorescein in the footprint. Others believe that fluorescein fills intercellular spaces. Others suggest that cells themselves stain with fluorescein.

METHODS

Rabbit corneas were stained with fluorescein and examined with the biomicroscope and later with a higher magnification epifluorescent microscope following excision.

RESULTS

Fluorescein staining was shown to be due to staining of individual cells. No evidence was found to support the contention that fluorescein resides in areas of cell drop out, or that staining was due to filling of intercellular spaces. Micropunctate staining is shown to be due to staining of cells in an optimum manner, which is referred to as hyperfluorescence.

CONCLUSIONS

The recognition that fluorescein stains cells, even in the case of epithelial abrasion, allows reinterpretation of many staining phenomena, including "salt and pepper" staining.

Rotational dynamics of calcium-free calmodulin studied by 15N-NMR relaxation measurements

The backbone motions of calcium-free Xenopus calmodulin have been characterized by measurements of the 15N longitudinal relaxation times (T1) at 51 and 61 MHz, and by conducting transverse relaxation (T2), spin-locked transverse relaxation (T1 rho), and 15N-[1H] heteronuclear NOE measurements at 61 MHz 15N frequency. Although backbone amide hydrogen exchange experiments indicate that the N-terminal domain is more stable than calmodulin's C-terminal half, slowly exchanging backbone amide protons are found in all eight alpha-helices and in three of the four short beta-strands. This confirms that the calcium-free form consists of stable secondary structure and does not adopt a 'molten globule' type of structure. However, the C-terminal domain of calmodulin is subject to conformational exchange on a time scale of about 350 microseconds, which affects many of the C-terminal domain residues. This results in significant shortening of the 15N T2 values relative to T1 rho, whereas the T1 rho and T2 values are of similar magnitude in the N-terminal half of the protein. A model in which the motion of the protein is assumed to be isotropic suggests a rotational correlation time for the protein of about 8 ns but quantitatively does not agree with the magnetic field dependence of the T1 values and does not explain the different T2 values found for different alpha-helices in the N-terminal domain. These latter parameters are compatible with a flexible dumb-bell model in which each of calmodulin's two domains freely diffuse in a cone with a semi-angle of about 30 degrees and a time constant of about 3 ns, whereas the overall rotation of the protein occurs on a much slower time scale of about 12 ns. The difference in the transverse relaxation rates observed between the amides in helices C and D suggests that the change in interhelical angle upon calcium binding is less than predicted by Herzberg et al. Strynadka and James [Strynadka, N. C. J. & James, M. N. G. (1988) Proteins Struct. Funct. Genet. 3, 1-17].

Diagnosis and surgical treatment of bronchogenic cysts

Between 1974 and 1993, 22 patients with bronchogenic cysts were operated on in our hospital; there were 14 men and 8 women, ranging in age from 11 to 62 years. The cyst locations were mediastinal in 13 (59.1%) and intrapulmonary in 9 (40.9%). There were symptoms (chest pain and recurrent bronchiolitis) in 20 patients (91%). The preoperative complications included infection in the lung and in the cyst and dysphagia due to esophageal compression. Chest pain was the main symptom in mediastinal cyst and recurrent infection of lung in intrapulmonary cyst. Plain chest radiograms showed that a round shadow, occasional air-fluid levels, and peripheral calcification may be found in cysts. An operation is the best treatment for cysts. All cysts were completely excised. No postoperative complications, late complications, or recurrence developed in our patients.

Adenosine receptors: protein and gene structure

Adenosine produces a wide variety of effects throughout the body via activation of cell surface adenosine receptors. Adenosine receptors belong to the family of seven transmembrane domain G protein-coupled receptors and four subtypes have been cloned from a variety of species: the A1AR, A2aAR, A2bAR and A3AR. With a knowledge of both the protein sequence of adenosine receptors and the structure of the A1AR gene, the function and regulation of these receptors can be further explored. Site-directed mutagenesis of the A1AR has resulted in the identification of amino acid residues in transmembrane domains 6 and 7 that are critical in both agonist and antagonist binding. The construction and analysis of A1/A3 chimeric receptors has also revealed regions of adenosine receptors important in ligand binding. These include the distal region of the second extracellular loop of adenosine receptors, which has a role in the binding of both agonist and antagonist ligands. A segment of the exofacial portion of the transmembrane domain 5 of adenosine receptors appears to be involved in the selective recognition of agonist ligands containing a substitution at the 5'-position of the ribose moiety. Isolation of the genomic sequence of the human A1AR, in combination with analysis of the transcript distribution in several tissues, indicates that alternative splicing of the human A1AR occurs in the 5'-untranslated region of the gene. Two distinct transcripts, containing either exons 3, 5 and 6 or exons 4, 5 and 6, exist with exons 3 and 4 apparently mutually exclusive. The exon 4, 5 and 6 transcript has been detected in all tissues that express the A1AR, while the exon 3, 5 and 6 mRNA is found in tissues that display a relatively high A1AR expression. Findings suggest that the presence of two ATG codons in exon 4, upstream of the translation start site, is involved in the repression of the A1AR expression in those tissues containing the exon 4, 5 and 6 transcript.

A clinical analysis of 38 patients with primary tracheo bronchial tumors

During a 17-year period, 38 patients with primary tracheobronchial tumors received surgical treatment in PUMC Hospital. Among the 38, 12 had low-malignancy tracheal tumors, 11 had benign tracheal tumors, 14 had low malignancy bronchial tumors and 1 had a benign bronchial tumor. Fifteen operations were performed on 12 patients with low-malignancy tracheal tumors, including local resection of the tumor and tracheal wall in 4 and curettage of the tumor plus electrical cauterization in 10. Postoperative radiotherapy was used as an adjuvant treatment in 8 patients with adenocystic carcinoma. Eight patients have survived for more than 5 years and 3 patients have survived for longer than 10 years postoperatively. All 11 patients with benign tumors received curettage of the tumor and were followed up for an average of 6.5 years. Among them, 9 are still alive. Of the 14 patients with low malignancy bronchial tumors, 5 underwent curettage of the tumor plus electrical cauterization through incision of the main bronchus or intermedial bronchus, and 7 underwent lobectomy or pneumonectomy. The authors conclude that the correct diagnosis rate can be increased by enhancing recognition of this disease and applying tracheal tomography and bronchoscopy.

Comparative observations on the types of atrophic gastritis and biopsy pathology of gastric mucosa

300 cases of chronic atrophic gastritis were classified into 3 types of qi-deficiency of spleen and stomach, yang-deficiency of spleen and stomach, and yin-deficiency of spleen and stomach according to syndrome differentiation of traditional Chinese medicine. The biopsy specimens of gastric mucosa were examined histopathologically and for the presence of pyloric spirobacteria. The results showed that the type of yin-deficiency was the most serious in the degree of pathologic changes, or the glandular atrophy and the interstitial inflammatory cellular infiltration, while the rate of pyloric spirobacteria presence was comparable in all types.

[The clinical characters and treatment of lung cancer in youth]

From January 1970 to December 1990, 67 patients with lung cancer aged younger than 40 years, were treated in the PUMC Hospital. There were 43.3% with SCLC and 37.3% with adenocarcinoma. Twenty-eight patients underwent resection of the lung. Thirty-five cases received chemotherapy or radiotherapy only. The clinical and pathological characteristics of lung cancer in youth, and the influence of surgical and non=surgical treatments to the patients with lung cancer are discussed. The authors consider that the bronchoscopic and sputum smear examinations are very helpful for diagnosing lung cancer in the early stage. Postoperative adjuvant chemo- and radio-therapy is suggested because of the high incidence of SCLC and adenocarcinoma in the young patients with lung cancer.

[Analysis of the influence factors on the resection and prognosis of thymic tumors]

One hundred eleven thymic tumors were intervened surgically, including 92 thymoma, 8 thymic carcinoid, and 10 thymic carcinoma. In this series 50.9% of the cases were complicated with various syndrome, 44.5% with myasthenia gravis (MG), more frequently in the epithelial cell type. Pure red cell aplasia often associated with the spindle-cell thymoma. Of the thymic carcinoid 50% had ectopic ACTH syndrome. Resection rate correlated with the size and invasion of the tumor. There were significant difference in resection rate among thymoma, thymic carcinoid, and thymic carcinoma. The degree of invasion undoubtedly influenced on resection. The 3-, 5-, and 10-year survival rates of the thymoma were 82.7%, 68.1% and 40.0% respectively. The prognosis depended on the pathological classification and the severity of neighbouring invasion, but MG had no significant effect on prognosis. Recurrence and metastasis of the tumor remained to be the main cause of late death.

Characterization of the lanthanide ion-binding properties of calcineurin-B using laser-induced luminescence spectroscopy

Calcineurin (CaN) is a Ca2+/calmodulin-dependent protein phosphatase found in brain and other tissues. It is a heterodimer consisting of a catalytic subunit (CaN-A) and a Ca(2+)-binding regulatory subunit (CaN-B). The primary structure of CaN-B indicates that it, like calmodulin, is an EF-hand protein and binds four Ca2+ ions. Eu3+, due to its favorable spectroscopic and chemical properties, has been substituted for Ca2+ in CaN-B to determine the metal ion-binding properties of this "calmodulin-like" protein. Excitation of the 7F0-->5D0 transition of Eu3+ results in a spectrum similar to that of calmodulin, consisting of three peaks. Analysis of the spectral titration curves reveals four Eu(3+)-binding sites in CaN-B. The affinities vary: sites I and II have dissociation constants of 1.0 +/- 0.2 and 1.6 +/- 0.4 microM, respectively; the values for sites III and IV are Kd = 140 +/- 20 and Kd = 20 +/- 10 nM, respectively. Binding of Tb3+ is slightly weaker. Tb3+ luminescence, sensitized by tyrosine, reveals that for lanthanides the highest affinity sites lie in the C-terminal domain. Energy transfer distance measurements between Eu3+ and Nd3+ in sites III and IV reveal a separation of 10.5 +/- 0.5 A, which suggests that these sites are arranged in a typical EF-hand pair. This information indicates that the overall structure of CaN-B is similar to the dumbbell-shaped proteins troponin-C and calmodulin, but is more like TnC in its metal-binding properties.

The effect of ultraviolet-B irradiation on the cell shedding rate of the corneal epithelium

In this study cell shedding rates of the corneal epithelium were determined in vitro following a single suprathreshold dose of ultraviolet-B irradiation. Rabbit corneas were excised and superfused in pairs. The epithelial and endothelial surfaces were bathed with solutions containing essential ions and adjusted to appropriate pH and osmolality. One cornea in each pair was irradiated, while the other cornea served as a control. Shed cells were periodically collected from the corneal surface and the shedding rate determined by counting the number of cells in a 50 min time period. Following a latent period of about 3 h, the epithelial shedding rate accelerated, and remained elevated for at least 8 h after irradiation. This result suggests that suprathreshold doses of ultraviolet-B irradiation disrupt the normal orderly cell shedding process and homeostatic equilibrium of the corneal epithelium. The elevated cell shedding rate exposes subsurface nerve endings and causes the characteristic pain of photokeratitis.

Posttranscriptional mRNA processing as a mechanism for regulation of human A1 adenosine receptor expression

The human A1 adenosine receptor gene contains six exons with exons 1, 2, 3, 4, and part of 5 representing 5' untranslated regions. Reverse transcription-PCR with exon-specific primers showed two distinct transcripts containing either exons 3, 5, and 6 or exons 4, 5, and 6, with exons 3 and 4 being mutually exclusive. No mature mRNAs containing exons 1 and 2 have been detected. All human tissues that express any A1 receptors contain mRNA with exons 4, 5, and 6. Tissues which express high levels of A1 receptors contain mRNA with exons 3, 5, and 6. Exon 4 contains two upstream ATG codons whereas exon 3 contains none. COS cells transfected with expression vectors containing exon 4 (exons 1-6, 3-6, or Ex4-6) express much lower levels of A1 receptors than vectors without exon 4 (exons 3, 5, and 6). Mutation of upstream ATG codons in exon 4 leads to 3- to 7-fold increased A1 receptor expression, up to the level seen with the construct containing exons 3, 5, and 6. Thus, in human tissues "basal" levels of A1 receptors can be expressed by use of mRNA containing exons 4, 5, and 6, but when high levels are needed, alternative transcripts with exons 3, 5, and 6 are produced.

1H, 13C, 15N nuclear magnetic resonance backbone assignments and secondary structure of human calcineurin B

The calmodulin- and calcium-stimulated protein phosphatase calcineurin, PP2B, consists of two subunits: calcineurin B, which binds Ca2+, and calcineurin A, which contains the catalytic site and a calmodulin binding site. Heteronuclear 3D and 4D NMR experiments were carried out on a recombinant human calcineurin B which is a 170-residue protein of molecular mass 19.3 kDa, uniformly labeled with 15N and 13C. The nondenaturing detergent CHAPS was used to obtain a monomeric form of calcineurin B. Three-dimensional triple resonance experiments yielded complete sequential assignment of the backbone nuclei (1H, 13C, and 15N). This assignment was verified by a 4D HN(COCA)NH experiment carried out with 50% randomly deuteriated and uniformly 15N- and 13C-enriched calcineurin B. The secondary structure of calcineurin B has been determined on the basis of the 13C alpha and 13C beta secondary chemical shifts, J(HNH alpha) couplings, and NOE connectivities obtained from 3D 15N-separated and 4D 13C/15N-separated NOESY spectra. Calcineurin B has eight helices distributed in four EF-hand, helix-loop-helix [Kretsinger, R. H. (1980) CRC Crit. Rev. Biochem. 8, 119-174] calcium binding domains. The secondary structure of calcineurin B is highly homologous to that of calmodulin. In comparison to calmodulin, helices B and C are shorter while helix G is considerably longer. As was observed for calmodulin in solution, calcineurin B does not have a single long central helix; rather, helices D and E are separated by a six-residue sequence in a flexible nonhelical conformation.

Influence of alloferin on neuromuscular function in myasthenia patients undergoing thymectomy

Myasthenia gravis patients are hypersensitive to nondepolarizing relaxants, such as alcuronium, an intermediate-long nondepolarizing agent. This study observed the effects of alcuronium treatment in myasthenia gravis patients as compared with non-MG patients during operation. Ten MG patients (Ossermann class I-IV, scheduled for thymectomy) and 10 non-MG patients (ASA class I-II, scheduled for operation) were selected. An induction dose of alcuronium 0.2 mg/kg and thiopental 4-6 mg/kg was given, followed by intubation and ventilation with 50% nitrous oxide in oxygen and 0.5-1.5% ethrane. Neuromuscular transmission was monitored using an accelerograph and degrees of neuromuscular function at different depths were recorded. There were statistically significant differences between the two groups. The effect of alloferin in the MG group was quicker and deeper. This study also found a relation between MG class and the recovery of respiration: Respiratory recovery was quicker in classes I-II than in classes III-IV.

Characterization of the human A1 adenosine receptor gene. Evidence for alternative splicing

To approach transcriptional and translational regulation of adenosine receptors, we have isolated cDNA and genomic clones of the human A1 adenosine receptor (A1AR). The cDNA, when inserted into the pCMV5 expression vector and transfected into COS-7 or CHO cells, leads to the expression of a functional A1AR that displayed all the appropriate pharmacologic properties. The human A1AR gene consists of at least six exons and five introns. A single intron interrupts the coding sequence, while the remaining introns are within the 5'-untranslated region. Comparison of our cDNA with one by Libert et al. (Libert, F., Van Sande, J., Lefort, A., Czernilofsky, A., Dumont, J. E., Vasart, G., Ensinger, H. A., and Mendla, K. D. (1992) Biochem. Biophys. Res. Commun. 187, 919-926) reveals that exon 4 in the 5'-untranslated region was completely missing from their sequence. Study of mRNAs from a range of human tissues by reverse transcription-polymerase chain reaction using a variety of primers revealed clear evidence for alternative splicing. Transcripts containing exons 4, 5, and 6 were found in all tissues expressing A1AR, while a separate transcript with exons 3, 5, and 6 was seen only in selected tissues. No transcript contains both exons 3 and 4. No evidence for expression of exons 1 and 2 could be discerned. Exon 4 contains two AUG initiation codons with reasonable Kozak consensus, suggesting the possibility of translational regulation. Exon 3 contains no AUG initiation codons.

Effect of albendazole on Ancylostoma caninum larvae migrating in the muscles of mice

When mice inoculated with 1,000 third-stage larvae of Ancylostoma caninum for 1 week were treated intragastrically (ig) with albendazole (Alb) 75, 150 or 300 mg/kg.d for 3 days, the mean larva numbers collected from the muscles of each group were 2.7 +/- 1.7, 2.0 +/- 1.5 and 1.0 +/- 1.0, respectively, being much less than that 205 +/- 68 of the control group. In mice treated ig with Alb 150 mg/kg.d for 3 days, the concentrations of Alb and its effective metabolite, albendazole sulfoxide (AlbSO), were determined in plasma and the muscles at different intervals after the last medication using high performance liquid chromatography. The results showed that only low concentrations of Alb were detected in both plasma and the muscles. However, higher concentrations of AlbSO were found not only in the plasma (5.4-10.5 micrograms/ml), but also in the muscles (2.2-4.6 micrograms/g). The higher contents of AlbSO in the muscles would be helpful for killing the Ancylostoma larvae migrating in the muscles of mice.

Preliminary report on cardiovascular responses to urapidil during intubation and extubation

Urapidil (Ebrantil), a new antihypertensive agent with central and peripheral sites of action, has proven effective in the management of both chronic and acute hypertension. This study investigates its effects on cardiovascular responses during intubation and extubation under general anesthesia. Thirty normotensive patients (ASA I-II) were randomized into control (I, without urapidil, n = 10); lower dose (II, 0.4 mg/kg, n = 10); and higher dose (III, 0.6 mg/kg, n = 10) groups. A significant fall of blood pressure was observed in all patients within 1 min after urapidil administration (P < 0.05), and the magnitude of the decrease was related to blood pressure before treatment. However, no transient drop of blood pressure to hypotensive values was observed. The results suggest that urapidil could be used under general anesthesia in patients to control fluctuating blood pressure during intubation and extubation. The increased heart rate (P < 0.05) seen for several minutes after urapidil administration may have been due to the patients' hypovolemic state.

Total gastrectomy via thoracotomy for cancer of the cardia or fundus of the stomach (report of 90 cases)

From 1978 through 1990, 90 total gastrectomies with esophagojejunostomy via thoracotomy were performed for the treatment of cancer of the cardia or fundus of the stomach in our hospital. Eighty-five patients were in TNM-stage III and five in stage IV. The 30-day postresectional mortality was 1.1%, and the 5-year survival rate was 13.8%. 14CO2 breathing test and clinical evaluation of 34 postoperative patients (not included in the 90 patients) showed that total gastrectomy may decrease the incidence of positive residual cancer along the incision lines, and may help to avoid small stomach syndrome. There was no statistical difference in postoperative fat absorption between patients treated by ordinary proximal subtotal gastrectomy and those receiving total gastrectomy via thoracotomy.

Hepatitis B virus infection in Honolulu students

OBJECTIVES

To determine hepatitis B virus (HBV) carrier and infection rates and HBV epidemiology in Honolulu students.

DESIGN

Cross-sectional survey.

SETTING

Honolulu public elementary, intermediate, and high schools.

PATIENTS

A volunteer sample of 4936 students from 43 Honolulu schools.

MAIN OUTCOME MEASURES

HBV carrier rate (presence of hepatitis B surface antigen) and infection rate (presence of either hepatitis B surface antigen, antibody to hepatitis B surface antigen, antibody to hepatitis B core antigen, or any combinations of these) by school grade, ethnicity, and place of birth.

RESULTS

Eighty-three (1.68%) students were identified as HBV carriers, and a total of 353 (7.15%) students had serologic evidence of infection. Infection rates increased from elementary school age to high school age, more so in Asian/Pacific Island-born students. The prevalence of infection was higher in Asian/Pacific Island-born students than in those born in the United States. The majority of infected Hawaiian-born students were first-generation Asian/Pacific Island Americans.

CONCLUSIONS

Horizontal transmission of HBV occurs in Honolulu school-age children. HBV immunization of all infants in Hawaii, not just those born to carrier mothers, is necessary to reduce HBV transmission in Hawaii.