A new method for early diagnosis of carcinoma in bile duct-sonography of common bile duct before and after injection of ceosunin

42 cases of dilatation (7-15 mm) of extrahepatic bile duct after ceosunin injection (cholagogic method) were observed ultrasonographically. Among the 18 cases of testified obstructive lesions of the bile duct, 13 (72%) showed widening of the bile duct with an increase of calibre from 9.8 mm to 11.7 mm, 3 (16%) had no obvious change, and 2 (12%) shrank. Among the 24 cases of non-obstruction 22 (92%) shrank with a decrease calibre from 9.6 mm to 6.3 mm, and 2 (8%) showed no obvious change. After receiving cholagogue, 9 cases of periampullary carcinoma in the obstructive group were confronted with widening of the bile duct calibre. After longitudinal and transverse rotation scanning method was used, 8 of the 9 cases had their tumor mass visualized. Combined cholagogic and rotation scanning methods raised the lesion manifestation rate of lower bile duct from 41% to 88%. A dilated bile duct unable to show shrinkage of calibre after cholagogue injection is believed to be a criterion for judging the presence of a suspicious case of bile duct obstruction. This criterion has a sensitivity of 89%, specificity of 92%, and accuracy of 90%.

Involvement of protein kinase C activation in alpha 2-adrenoceptor-mediated contractions of rabbit saphenous vein

The role of protein kinase C alpha 2-adrenoceptor-induced contractions of rabbit saphenous vein was investigated. Contractions induced by the alpha 2-adrenoceptor-selective agonist 5-bromo-6-[2-imidazolin-2-ylamino]-quinoline (UK14304) were inhibited by prior treatment with pertussis toxin and by Ca2+ removal, confirming a Gi/Go-dependent coupling pathway which was highly dependent upon Ca2+ influx. Protein kinase C inhibitors calphostin-C and staurosporine each caused a non-competitive inhibition of UK14304 response. Down-regulation of protein kinase C by pretreatment with tetradecanoylphorbol acetate reduced UK14304 response by almost 90% with no effect on contractions induced by elevated KCl. The ineffectiveness of L-type Ca2+ channel blockers and the absence of stimulated 45Ca2+ uptake or efflux by UK14304 indicated that phospholipid-derived products were most likely responsible for protein kinase C activation. alpha 2-Adrenoceptor stimulation failed to increase [3H]myoinositol phosphate formation, but caused a significant increase in the formation of both [32P]phosphatidic acid and diacylglycerol, indicating the possible activation of phospholipase D activity. These results suggest that protein kinase C is important for the vasoconstriction induced by alpha 2-adrenoceptors and that diacylglycerol derived from receptor-initiated phospholipase D activity may provide protein kinase C stimulation.

[Congenital pulmonary lymphangiectasis]

Six rare cases of congenital pulmonary lymphangiectasis were presented. The macroscopic characteristic of the lungs was honeycomb appearance due to extreme dilatation of the lymphatic spaces in the subpleural, interlobular, peribronchial and perivascular connective tissue. They had thin walls lined by endothelium. The dilated lymphatics may be due to congenital developmental defects or obstruction of major lymphatics, but they appeared to be associated only with pulmonary venous hypertension.

Measurement and correction of ultrasonic pulse distortion produced by the human breast

Ultrasonic wavefront distortion produced by transmission through breast tissue specimens was measured in a two-dimensional aperture. Differences in arrival time and energy level between the measured waveforms and references that account for geometric delay and spreading were calculated. Also calculated was a waveform similarity factor that is decreased from 1.0 by changes in waveform shape. For nine different breast specimens, the arrival time fluctuations had an average (+/- s.d.) rms value of 66.8 (+/- 12.6) ns and an associated correlation length of 4.3 (+/- 1.1) mm, while the energy level fluctuations had an average rms value of 5.0 (+/- 0.5) dB and a correlation length of 3.4 (+/- 0.8) mm. The corresponding waveform similarity factor was 0.910 (+/- 0.023). The effect of the wavefront distortion on focusing and the ability of time-shift compensation to remove the distortion were evaluated by comparing parameters such as the -30-dB effective radius, the -10-dB peripheral energy ratio, and the level at which the effective radius departs from an ideal by 10% for the focus obtained without compensation, with time-shift estimation and compensation in the aperture, and with time-shift estimation and compensation performed after backpropagation. For the nine specimens, the average -10-dB peripheral energy ratio of the focused beams fell from 3.82 (+/- 1.83) for the uncompensated data to 0.96 (+/- 0.18) with time-shift compensation in the aperture and to 0.63 (+/- 0.07) with time-shift compensation after backpropagation. The average -30-dB effective radius and average 10% deviation level were 4.5 (+/- 0.8) mm and -19.2 (+/- 3.5) dB, respectively, for compensation in the aperture and 3.2 (+/- 0.7) mm and -22.8 (+/- 2.8) dB, respectively, for compensation after backpropagation. The corresponding radius for the uncompensated data was not meaningful because the dynamic range of the focus was generally less than 30 dB in the elevation direction, while the average 10% deviation level for the uncompensated data was -4.9 (+/- 4.1) dB. The results indicate that wavefront distortion produced by breast significantly degrades ultrasonic focus in the low MHz frequency range and that much of this degradation can be eliminated using wavefront backpropagation and time-shift compensation.

[Biomechanical evaluation of cervical stability with Halifax clamp after bilateral facetectomy]

With nine fresh adult cervical spine specimens (C3-T1), the three-dimensional motions of C4-5 segment were analysed to evaluate the immediate stability following bilateral facetectomy, Halifax clamp and wire fixation. The results showed that the stability with Halifax clamp was greater than that of the intact state in flexion, extension and lateral bending, but the same as in axial rotation. The stability with wire fixation was greater than that in flexion and equal to that in extension, lateral bending and axial rotation. The ROMs with Halifax Clamp were less than those with wire fixation in flexion, extension and lateral bending, but close to in axial rotation.

Structural basis for pleckstrin homology domain mutations in X-linked agammaglobulinemia

Deficiencies in a tyrosine kinase, designated Btk, cause X-linked agammaglobulinemia (XLA) in man, a hereditary defect of B-cell differentiation. Mutations in the newly found PH domain located at the N-terminus of Btk have been shown to be the direct cause of XLA, and here two new mutations, T33P and V64F, are presented. Btk is thus far the only protein in which mutations of the PH domain have been found to cause a disease. The three-dimensional structure of the Btk PH domain was modeled on the basis of the dynamin PH structure. Despite a relatively low sequence similarity the Btk PH domain seems to have the same two beta-sheet structure observed in the known structures. The model was used to interpret the structural basis for disease in five independent point mutations and in an insertion in patients with XLA. The mutated residues F25, V64, and V113, and possibly residue(s) around Q103, could form a binding site, since these amino acids are located close to each other on the surface of the molecule.

[Detection and quantification of lipoprotein (a) in atherosclerotic lesions of human aorta]

Lipoprotein(a) [Lp(a)] represents an independent risk factor for atherosclerotic disease. In the present study, the extent to which Lp(a) accumulated in normal and various degrees of atheromatous lesions and the distribution pattern of Lp(a) in these lesions have been studied in thoracic aorta from the autopsy tissues by means of immunohistochemistry, immunoelectronic microscopy, enzyme-linked immunosorbent assay and computer-assisted image processing. Lp(a) was found to be localized preferentially in lesion areas and had its own distribution pattern in each kind of lesion. Lp(a) associated primarily with extracellular matrix and was detected in only a small number of foamy cells. Apolipoprotein B was also detected, whose staining pattern was always found to be congruent with that of Lp(a). This suggests that the immunoreactivity of apoB is related to the presence of Lp(a) at least in part, since Lp(a) possesses apoB in addition to apo(a). It was concluded that both low density lipoprotein and lipoprotein(a) play an important role in the pathogenesis of atherosclerosis.

Chinese character operating system of traditional Chinese medicine and pharmacology (TCMP)

With the development in research, teaching and literature work in traditional Chinese medicine and pharmacology (TCMP) by means of computers, it has been found that the existing Chinese character operative systems cannot meet the need of carrying out information processing and software development in this field, since these systems do not include many of the common and special terms in TCMP. This makes it inconvenient to exchange academic thoughts in information processing in this field with our colleagues at home and abroad and greatly affects the sharing of the literature data in TCMP. It is therefore necessary to develop a Chinese character operating system applicable to the use of computers in the research of TCMP. Recently, we have developed jointly a Chinese character operating system of TCMP. This system is based on the original GB2312-80 Chinese character international code, to which are added 1,150 Chinese characters commonly used in TCMP. The five-stroke code, which make input possible according to word forms, are used for the input of expanded words. Besides, the system also provides the codes of a number of common names of Chinese materia medica, acupoint names, common terms in traditional Chinese medicine (TCM), TCM disease names, names of classic TCM works, etc. It also provides a convenient character-creating software. We hope that our work will lead to discussions concerning the difficult problems in computer processing of TCMP literature, i.e. the Chinese character.

Structural basis for chromosome X-linked agammaglobulinemia: a tyrosine kinase disease

X-linked agammaglobulinemia (XLA) is a hereditary defect of B-cell differentiation in man caused by deficiency of Bruton tyrosine kinase (BTK). A three-dimensional model for the BTK kinase domain, based on the core structure of cAMP-dependent protein kinase, was used to interpret the structural basis for disease in eight independent point mutations in patients with XLA. As Arg-525 of BTK has been thought to functionally substitute for a critical lysine residue in protein-serine kinases, the mutation Arg-525-->Gln was studied and found to abrogate the tyrosine kinase activity of BTK. All of the eight mutations (Lys-430-->Glu, Arg-520-->Glu, Arg-525-->Gln, Arg-562-->Pro, Ala-582-->Val, Glu-589-->Gly, Gly-594-->Glu, and Gly-613-->Asp) were located on one face of the BTK kinase domain, indicating structural clustering of functionally important residues.

Destabilization of glial fibrillary acidic protein mRNA in astrocytes by ammonia and protection by extracellular ATP

The expression of the astrocyte-specific intermediate filament protein, glial fibrillary acidic protein (GFAP), is decreased in hepatic encephalopathy and increased in numerous neurological conditions including brain injury. However, little is known about the molecular mechanisms that regulate GFAP expression. Here it is reported that treatment of cultured astrocytes with ammonium chloride reduces GFAP mRNA by up to 85% without inhibiting total RNA synthesis. The effect of NH4Cl was time and dose dependent. The reduction in GFAP mRNA was detected 3 h after initiation of ammonia treatment with a maximum effect observed at 24 h. Significant decreases in GFAP mRNA were observed at 2, 5, and 10 mM NH4Cl. Concurrent treatment with extracellular ATP prevented the loss of GFAP mRNA, possibly by activation of purinergic receptors. In addition, removal of ammonium chloride restored GFAP mRNA to normal levels. Nuclear runoff experiments indicated that NH4Cl did not inhibit GFAP mRNA transcription. Studies using alpha-amanitin, an inhibitor of RNA polymerase II, showed that NH4Cl decreased the stability of GFAP mRNA by approximately 50%. This destabilization of GFAP mRNA may be an important factor in the pathogenesis of hepatic encephalopathy. Because increased GFAP is an important component of reactive gliosis, understanding the mechanisms that destabilize GFAP mRNA may facilitate strategies to minimize the gliosis associated with brain injury.

Chemical cross-linking of virion envelope and tegument proteins of herpes simplex virus type 1

The virion of herpes simplex virus type 1 (HSV-1) consists of three structural components which include the envelope, tegument, and capsid. Little is known about the organization and potential interaction of proteins of the tegument and envelope. In this report, studies with chemical cross-linking reagents were initiated to determine the arrangement of the HSV-1 glycoprotein B (gB) on the viral envelope and its interactions with other virion proteins. With use of four homobifunctional N-hydroxysuccinimide ester reagents, gB was cross-linked to dimers and eventually high molecular weight complexes. In addition, four virion structural proteins were detected to be associated with gB as well as gD and gH but not with gC when cross-linked with dithiobis(succinimidyl propionate). Experimental results indicated that these four proteins are likely to represent viral tegument proteins and one of these proteins was immunologically identified as the known tegument protein, VP16.

Differential ultrasonic diagnoses of pulmonary benign and malignant space-occupied lesions of the peripheral type

87 patients with pulmonary space-occupied lesions of the peripheral type which were either adhesive or close to pleura were examined using ultrasonography. Of them, 64 cases of lung cancers and 23 of benign lesions were then confirmed by histopathology. Five sonographic features, including configuration, echogenicity patterns, bronchial air phase in foci, margin, and pleural involvement, were significantly different between malignant and benign diseases (P < 0.01). The differential ultrasonography used in this series showed a sensitivity of 61% (14/23), a specificity of 95% (61/64), and an accuracy of 86% (75/87). The results of the study demonstrate that the ultrasonography is helpful in differentiating malignant and benign peripheral lung lesions near the plerua.

Twenty-four hour intermittent perfusion storage of the isolated rat heart: the effect of perfusion intervals on functional preservation

We investigated the effect of intermittent perfusion intervals on heart preservation. The isolated rat heart was flushed with a cardioplegic solution, CP-11EB, and stored at 0 degrees C for 24 hours. During storage, the heart was perfused periodically at 60 mm Hg for 3 minutes with 25 degrees C oxygenated CP-11EB. The perfusion schedules were as follows: group I, every 4 hours; group II, every 6 hours; group III, every 8 hours; group IV, every 10 hours; group V, 10 and 17 hours of storage; group VI, every 11 hours. Poststorage function was assessed after 30 minutes of working reperfusion. Function of the unstored hearts including aortic flow (51.5 +/- 2.5 ml/min), coronary flow (24.5 +/- 1.3 ml/min), cardiac output (75.6 +/- 3.0 ml/min) and work (85.0 +/- 5.4 g-ml/min) served as controls. Group V hearts were best preserved with aortic flow recovered to 65%; coronary flow 44%; cardiac output 58%; and work 53% of the control. Recovery in group IV was comparable with group V. Groups I, II, III, and VI recovered significantly less than group V. Myocardial adenosine triphosphate content (micromoles per gram dry) in group V was 23.8 +/- 1.7, 20.8 +/- 0.9, 13.5 +/- 2.4, and 15.0 +/- 4.0, at 0, 10, 17, and 24 hours of storage, respectively. Intermittent perfusion at 10 and 17 hours elevated adenosine triphosphate to 99% and 88% of prestorage level. Poststorage reperfusion did not improve improve adenosine triphosphate content (16.2 +/- 2.4) over the end-storage level.(ABSTRACT TRUNCATED AT 250 WORDS)

Signaling by ATP receptors in astrocytes

Treatment of primary cultures of rat cerebral cortical astrocytes with extracellular ATP caused a 3- to 4-fold stimulation of mitogen-activated protein (MAP) kinase activity. Studies with agonists and antagonists of P1 and P2 purinergic receptors indicated that this activation is mediated by ATP/P2 purinergic receptors rather than adenosine/P1 purinergic receptors. Increased cAMP levels did not significantly inhibit the activation of MAP kinase by ATP but did inhibit the stimulation of MAP kinase by basic fibroblast growth factor, a polypeptide growth factor that activates the Ras/Raf kinase signaling pathway. These data indicate that ATP/P2 purinergic receptors are coupled to MAP kinase by a signal transduction pathway that is independent of the Raf kinase pathway.

Cloning and sequence analysis of the promoter region of the MRP gene of HL60 cells isolated for resistance to adriamycin

Non-P-glycoprotein multidrug resistance of HL60/ADR cells appears to be related to overexpression of the MRP gene. Recent studies suggest that this gene may play an important role in a new form of cell resistance to certain chemotherapeutic agents. To examine mechanisms regulating transcriptional activity of this gene, a 2.2-kilobase 5'-flanking sequence of MRP has been isolated from a genomic library prepared from HL60/ADR cells. The 2.2-kilobase DNA fragment linked to the chloramphenicol acetyltransferase (CAT) gene in a reporter plasmid was found to be capable of driving expression of this gene in transient transfection experiments. This DNA containing promoter activity has been sequenced in its entirety and found to contain multiple putative regulatory sites. A series of deletion mutants linked to the CAT reporter gene was used to examine functional domains of the 2.2-kilobase sequence. The results suggest that promoter activity is contained in nucleotides -91 to +103 in a GC-rich region of the MRP genome. Promoter activity contained within this sequence, however, is modulated by both positive and negative regulatory elements. Certain of the regulatory sites contain consensus sequences for positive and negative regulatory elements which have been found in the promoter regions of other genes. Primer extension analysis indicates the presence of multiple major transcriptional start sites from the MRP promoter. Sequence analysis of MRP genomic and complementary DNAs has defined the exon/intron boundaries and the organization of a portion of the 5'-end region of the MRP genome. The results of these studies thus provide new insight in site-specific domains which may function in the regulation of MRP gene expression.

Deletion within the Src homology domain 3 of Bruton's tyrosine kinase resulting in X-linked agammaglobulinemia (XLA)

The gene responsible for X-linked agammaglobulinemia (XLA) has been recently identified to code for a cytoplasmic tyrosine kinase (Bruton's agammaglobulinemia tyrosine kinase, BTK), required for normal B cell development. BTK, like many other cytoplasmic tyrosine kinases, contains Src homology domains (SH2 and SH3), and catalytic kinase domain. SH3 domains are important for the targeting of signaling molecules to specific subcellular locations. We have identified a family with XLA whose affected members have a point mutation (g-->a) at the 5' splice site of intron 8, resulting in the skipping of coding exon 8 and loss of 21 amino acids forming the COOH-terminal portion of the BTK SH3 domain. The study of three generations within this kinship, using restriction fragment length polymorphism and DNA analysis, allowed identification of the mutant X chromosome responsible for XLA and the carrier status in this family. BTK mRNA was present in normal amounts in Epstein-Barr virus-induced B lymphoblastoid cell lines established from affected family members. Although the SH3 deletion did not alter BTK protein stability and kinase activity of the truncated BTK protein was normal, the affected patients nevertheless have a severe B cell defect characteristic for XLA. The mutant protein was modeled using the normal BTK SH3 domain. The deletion results in loss of two COOH-terminal beta strands containing several residues critical for the formation of the putative SH3 ligand-binding pocket. We predict that, as a result, one or more crucial SH3 binding proteins fail to interact with BTK, interrupting the cytoplasmic signal transduction process required for B cell differentiation.

One exon of the human LSF gene includes conserved regions involved in novel DNA-binding and dimerization motifs

The transcription factor LSF, identified as a HeLa protein that binds the simian virus 40 late promoter, recognizes direct repeats with a center-to-center spacing of 10 bp. The characterization of two human cDNAs, representing alternatively spliced mRNAs, provides insight into the unusual DNA-binding and oligomerization properties of LSF. The sequence of the full-length LSF is identical to that of the transcription factors alpha CP2 and LBP-1c and has similarity to the Drosophila transcription factor Elf-1/NTF-1. Using an epitope-counting method, we show that LSF binds DNA as a homodimer. LSF-ID, which is identical to LBP-1d, contains an in-frame internal deletion of 51 amino acids resulting from alternative mRNA splicing. Unlike LSF, LSF-ID did not bind LSF DNA-binding sites. Furthermore, LSF-ID did not affect the binding of LSF to DNA, suggesting that the two proteins do not interact. Of three short regions with a high degree of homology between LSF and Elf-1/NTF-1, LSF-ID lacks two, which are predicted to form beta-strands. Double amino acid substitutions in each of these regions eliminated specific DNA-binding activity, similarly to the LSF-ID deletion. The dimerization potential of these mutants was measured both by the ability to inhibit the binding of LSF to DNA and by direct protein-protein interaction studies. Mutations in one homology region, but not the other, functionally eliminated dimerization.

Synergistic activation of DNA synthesis in astrocytes by fibroblast growth factors and extracellular ATP

The effects of extracellular ATP and polypeptide growth factors on DNA synthesis in primary cultures of rat astrocytes have been examined. It was found that ATP acts synergistically with either acidic or basic fibroblast growth factor to stimulate DNA synthesis. The specificity of this effect was demonstrated by the inability of ATP to potentiate DNA synthesis induced by platelet-derived growth factor or epidermal growth factor. ATP appears to act via P2 purinergic receptors, because (a) it was more effective than adenosine and (b) the synergistic effect was observed with the hydrolysis-resistant P2 agonists, ADP beta S and ATP gamma S. The evidence suggests that extracellular ATP may be an important factor in regulating the extent of gliosis and, as such, may be involved in mechanisms of neural injury and repair.

Enhanced functional preservation of cold-stored rat heart by a nucleoside transport inhibitor

This study investigates the hypothesis that inhibition of nucleoside transport during hypothermic storage elevates tissue adenosine (ADO) content and improves the function of the isolated rat heart. The hearts, flushed with a cardioplegic solution containing varying concentrations (0-100 nM) of a nucleoside transport inhibitor, S-(4-nitrobenzyl)-6-thioinosine (NBTI), were immersion-stored at 0 degrees C for 9 hr. Function was assessed after 30 min of working reperfusion. Function of unstored fresh hearts served as controls and poststorage recovery is reported as percentage of control function. Poststorage heart rate in all groups returned to control level after reperfusion. Recovery of other functional parameters in the no-NBTI group was as follows: aortic flow (AF), 56.2 +/- 4.6%; coronary flow (CF), 53.9 +/- 3.2%; cardiac output (CO), 55.5 +/- 4.0%; systolic pressure, 81.6 +/- 2.5%; work, 47.0 +/- 4.2%; and coronary vascular resistance (CVR), 157.1 +/- 7.8% of control. NBTI improved functional recovery in a dose-dependent fashion; the maximal improvement was seen at a dose of 5 nM, in which the recovery was: AF, 78.1 +/- 3.4%; CF, 73.5 +/- 4.4%; CO, 76.7 +/- 3.6%; work, 70.7 +/- 5.0%; and CVR, 127.5 +/- 4.5% of control (P < 0.05 vs. no-NBTI). The ADO A1-receptor antagonist, 1,3-dipropyl-8-cyclopentylxanthine (0.1 microM) blocked the effects of 5 nM NBTI; the recovery of AF, CF, CO, work, and CVR decreased to 62.8 +/- 8.0%, 58.3 +/- 5.0%, 61.5 +/- 3.9%, 54.4 +/- 4.5%, and 163.8 +/- 12.7% of control, respectively (P < 0.05 vs. 5 nM NBTI). Tissue ADO content in 5 nM NBTI hearts at the end of storage was 0.075 +/- 0.025 mumol/g dry wt, which was significantly elevated from 0.016 +/- 0.004 mumol/g dry wt in no-NBTI hearts. Purine release during initial reperfusion was delayed in 5 nM NBTI hearts, indicating the inhibition of nucleoside transport by NBTI. But NBTI treatment did not improve end-storage or end-reperfusion myocardial ATP. In conclusion, the addition of NBTI to cardioplegic solution enhanced tissue ADO and improved poststorage function of the hypothermically stored rat heart. The effect is ADO A1-receptor mediated without invoking energy conservation.

Wavefront amplitude distribution in the female breast

Ultrasound measurements of a large population of wavefronts transmitted through female breasts at 3 and 4 MHz show that the wavefront amplitude distribution is close to Rayleigh. This finding is consistent with a fully developed scatter field, implying that the scatter energy removed from the coherent incident beam dominates the wavefront. The wavefront received from an inhomogeneous medium is the superposition of an incident wave plus a scattered wave. If the scattered field is weak, the received field is dominated by the incident field and the wavefront amplitude distribution is Rician. If the scattered field is strong, the received field is primarily the scattered field and the wavefront amplitude distribution is Rayleigh. If, in addition to scattering, refraction between bodies of different refractive indexes occurs, the total net effect on the wavefront amplitude distribution is the same as for strong scattering. This is what we have observed in the highly refractive female breast. This result has implications for the design of high lateral-resolution echo scanners that will incorporate adaptive phase deaberration algorithms. The published algorithms were developed for weak scattering and therefore may not be powerful enough. Alternatives have to be found to deaberrate the severe wavefront distortion in the breast.

Isolation of a monocot 3-hydroxy-3-methylglutaryl coenzyme A reductase gene that is elicitor-inducible

The rice (Oryza sativa) phytoalexins, momilactones and oryzalexins, are synthesized by the isoprenoid pathway. An early step in this pathway, one that is rate-limiting in mammalian systems, is catalyzed by the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR). A gene that encodes this enzyme has been isolated from rice, and found to contain an open reading frame of 1527 bases. The encoded protein sequence of the rice HMGR appears to be conserved with respect to other HMGR proteins, and 1 or 2 membrane-spanning domains characteristic of plant HMGRs are predicted by a hydropathy plot of the amino acid sequence. The protein is truncated at its 5' end, and shows reduced sequence conservation in this region as compared to other plant sequences. The rice genome contains a small family of HMGR genes. The isolated gene, HMGR I, is expressed at low levels in both vegetative and floral organs of rice plants. It is not induced in plants by wounding, but is strongly and rapidly induced in suspension cells by a fungal cell wall elicitor from the pathogen Magnaporthe grisea, causal agent of rice blast disease. This suggests that HMGR I may be important in the induction of rice phytoalexin biosynthesis in response to pathogen attack, and therefore may play a key role as a component of the inducible defense mechanism in rice.

Transcutaneous ultrasound of the cervical esophagus in patients with esophageal carcinoma

Transcutaneous ultrasound of the cervical esophagus was performed in 46 patients with esophageal carcinoma and in 35 controls. The former had 24 upper segmental lesions and 22 lower segmental lesions. The level of the sternoclavicular joint was used to divide the esophagus into the upper segmental (USE) and lower segmental esophagus (LSE). The anterior esophageal wall thickness and luminal dimensions were measured before and immediately after phonation. The mean wall thickness in the controls was 1.8 mm before phonation and 2.1 mm after phonation, with a significant difference (t test, P < 0.05). The mean wall thickness in the USE carcinoma group was 4.3 mm and 4.4 mm before and after phonation respectively. There was a significant difference between the controls and USE carcinoma groups (t test, P < 0.05). The cross sectional area, which was calculated as the product of anterio-posterior and lateral diameters, averaged 28 mm2 before phonation in the controls and increased to 44 mm2 after phonation (t test, P < 0.05). The mean cross sectional area in the USE carcinoma group was significantly smaller before phonation than that in the controls (t test, P < 0.05) and showed little change after phonation. No significant difference was found between LSE carcinoma and control groups. Transcutaneous ultrasound appears to be a promising non-invasive method of investigation for cervical esophageal carcinoma.

Experimental studies of the inhibitory effects of green tea catechin on mice large intestinal cancers induced by 1,2-dimethylhydrazine

Three hundred Kunming mice were randomly divided into six groups (half males and half females in each group). Group 1 was the positive control group, Groups 2, 3, 4 and 5 were experimental groups and Group 6 was used as the solvent control group. Mice in Groups 1-4 were injected with 1,2-dimethylhydrazine (1,2-DMH) (20 mg/kg body wt.) solution subcutaneously once a week from the 2nd week to the 20th week. From the 1st week to the 23rd week, mice in Groups 2, 3 and 4 were given catechin (1 mg/mouse), catechin (2 mg/mouse) and EGCG (2 mg/mouse), respectively, five times a week. Mice in Group 5 received only catechin (3 mg/mouse) five times a week from the 1st to the 23rd week. Mice in Group 6 were injected with an equal volume of 1 mmol EDTA solution subcutaneously once a week from the 2nd to the 20th week. At the end of the 27th week, all the mice were killed by cervical dislocation (Zhu, Q.H. and Zhu, Q.F. (1991) Laboratory Animal Science, 1st edition. The Junior Educational Publisher, Guangdong). Pathological examinations indicated that the incidence of large intestinal cancers occurring in Group 1 was 80%, significantly higher than that in Groups 2, 3 and 4 (p < 0.001). No tumors were found in Groups 5 and 6. This might suggest that green tea has preventive effects on large intestinal cancer induction in spite of the different doses of catechin. Immunohistochemistry studies showed that green tea catechins could enhance the activity of superoxide dismutase (SOD) in tissues.

Measurement by confocal laser scanning microscopy of the volume of epidermal nuclei in thick skin sections

The mean volume and shape of nuclei assessed in standard tissue sections by means of stereologic and morphometric methods are associated with prognosis in tumors of different sites. Thus, accurate quantification of the volume and shape of cell nuclei can be important for cancer patients and also may be useful for a better understanding of basic cellular events, such as growth and differentiation. Confocal laser scan microscopy (CLSM) makes it possible to obtain image sets consisting of very thin serial optical slices from thick tissue sections. These images can be used with digital image processing to construct a three-dimensional (3-D) model of individual nuclei. We used CLSM to study a 50-micron-thick paraffin section of a skin biopsy. Image processing was applied to the CLSM images to precisely segment epidermal nuclei from the background, and serial two-dimensional (2-D) binary images were created. Alignment of the 2-D images that form the 3-D model of the original nuclei was carefully controlled. The series of 2-D binary images was connected with an algorithm to form the 3-D model of each complete nucleus and organized for the 3-D visualization and analysis using a 3-D volume rendering method. In this way we measured the volume and surface area of 22 intact epidermal nuclei. The mean nuclear volume was 174.7 micron3, the standard deviation of the volume 26.47 micron3, the mean surface area 168.0 micron2 and the standard deviation of the surface area 22.00 micron2.(ABSTRACT TRUNCATED AT 250 WORDS)

Antifreeze glycoproteins from antarctic notothenioid fishes fail to protect the rat cardiac explant during hypothermic and freezing preservation

The antarctic notothenioid fishes avoid freezing through the action of circulating antifreeze glycoproteins (AFGPs). This study investigated whether AFGPs could serve as cryoprotectants for the isolated rat heart under three different storage conditions. (1) Hearts were flushed with 15 mg AFGP/ml cardioplegic solution (CP) and stored for 9 h at 0 degrees C. This AFGP concentration has been reported to protect pig oocytes during hypothermic storage. (2) Hearts were flushed with 10 mg AFGP/ml CP-14 and stored frozen at -1.4 degrees C for 3 h. At this concentration the AFGPs significantly reduce the solution freezing point and also change the crystal morphology from dendritic to spicular. (3) Hearts were flushed with 10 micrograms AFGP/ml CP-15 and stored frozen at -1.4 degrees C for 5 h. At this low concentration the AFGPs have a strong inhibitory effect on ice recrystallization, but have little effect on the freezing point and less apparent effect on the crystal habit. After hypothermic or freezing storage, the functional viability was assessed by determining cardiac output (CO) during working reperfusion. No difference in CO was found between AFGP-treated and untreated hearts after 9 h of 0 degree C storage. CO in hearts frozen in CP-14 without AFGPs recovered to 50% of the freshly perfused control hearts. Hearts frozen in the presence of high concentrations of AFGPs (10 mg/ml CP-14) failed to beat upon thawing and reperfusion, although their tissue ice content was less than that found in hearts without AFGP treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy of cefazolin in promoting ovine tracheal epithelial repair

Inhalation of toxic materials has been shown injurious to the upper airways. Because secondary infection can slow the repair process, we undertook this study to determine the efficacy of antibiotic therapy in promoting the healing process of acute tracheal wounds. In 18 anesthetized sheep, a portion of the cervical trachea was exposed to smoke from smoldering cotton cooled to 38 degrees C. Nine received the broad-spectrum antibiotic, cefazolin, while none received saline placebo. At 13 days after injury, nonciliated and ciliated cell counts were 75% and 33% respectively of noninjured trachea receiving placebo, while in those receiving cefazolin, nonciliated and ciliated cell counts increased to 93% and 114% of paired noninjured trachea, respectively. We suggest that cefazolin therapy allows cell proliferation and differentiation to proceed more rapidly than observed with placebo therapy and thus may be a helpful augmentor to the healing of an acute airway injury.

Adenosine deaminase inhibitor in cardioplegia enhanced function preservation of the hypothermically stored rat heart

Adenosine (ADO) has been shown to be protective to the ischemic-reperfused myocardium. This study tested the hypothesis that inhibition of myocardial adenosine deaminase during cold storage will elevate tissue ADO content, improve the cardiac function, and preserve ATP. The isolated rat hearts (6-9 hearts/group) were flushed with a cardioplegic solution containing 0-75 microM erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA) and immersion-stored at 0 degree C for 9 hr. Function was assessed after 30 min working reperfusion. Function of the unstored hearts (n = 11, mean +/- SE) including heart rate (293 +/- 13 bpm), aortic flow (AF; 52.5 +/- 1.1 ml/min), coronary flow (CF; 23.5 +/- 1.3 ml/min), cardiac output (CO; 76.0 +/- 2.1 ml/min), systolic pressure (SP; 136 +/- 2 mmHg), diastolic pressure (DP; 63 +/- 1 mm Hg), work (90.5 +/- 3.4 g-m/min), and coronary vascular resistance (CVR; 2.77 +/- 0.14 mmHg-min/ml) served as controls. Heart rate in all stored hearts returned to normal after reperfusion. Recovery of other function in no-EHNA group was: AF, 52 +/- 7; CF, 55 +/- 5; CO, 53 +/- 6; SP, 79 +/- 4; DP, 93 +/- 3; work, 47 +/- 7; and CVR, 171 +/- 15% of control. EHNA improved functional recovery in a dose-dependent fashion. At the optimal concentration of 25 microM, the recovery was: AF, 83 +/- 6; CF, 68 +/- 4; CO, 78 +/- 5; SP, 90 +/- 3; DP, 105 +/- 5; work, 77 +/- 8; and CVR 151 +/- 9% of control. ADO A1 receptor antagonists, 8-phenyltheophylline (1 microM) and 1,3-dipropyl-8-cyclopentylxanthine (0.1 microM) blocked the effects of 25 microM EHNA; the recovery of CO was reduced to 65 +/- 3 and 50 +/- 2% of the control, respectively. Tissue ADO content in 25 microM EHNA hearts at the end of storage was 95 +/- 19 nmol/g dry wt, which was significantly elevated from 15 +/- 3 nmol/g dry wt in no-EHNA hearts. EHNA also caused a 45-fold increase in the release of ADO over no-EHNA group during the first 10 min of reperfusion. But EHNA treatment did not cause any change in either end-storage or end-reperfusion myocardial ATP levels. Thus EHNA in cardioplegic solution inhibited cardiac ADO catabolism during long-term hypothermic storage and improved function preservation partially via an ADO A1 receptor-mediated mechanism without invoking ATP conservation.

[Studies on anti-inflammatory protein from the extraction of the larva of Parasa sinica Moore]

As a kind of anti-inflammatory protein fractionated and purified from the larva of parasa sinica, CCP (ip) has a significant anti-inflammatory effect on ear odema induced by croton oil in mice. Its ID50 is 1.6mg/kg, but a dose of 2.5mg/kg can also significantly inhibit the rat ankle odema induced by carrageenan and egg white.

In situ preparation of rat tracheal basal cells

The primary function of basal cells is to attach columnar epithelium to the basal lamina. They may also have limited stem cell potential, but very little is known of other biological functions. Basal cells lie on the basal lamina beneath the ciliated and secretory cells and do not reach the surface of the epithelium. The position of the cell beneath the ciliated and secretory cell epithelium makes their in situ study difficult. In order to further aid in the study of basal cells, we have developed an in situ preparation technique in which ciliated and secretory cells are removed. Treatment of rat tracheas with a 20 mM Na2 EDTA solution, pH 7.4, results in partial removal of columnar epithelium from the basal lamina. The percent of denuded columnar epithelial cells per mm of basal lamina is 43.9 +/- 7.8% at 60 min, 47.6 +/- 8.4% at 90 min, and 52.6 +/- 2.7% at 120 min. The viability of the exposed basal cells was the same at both 60 and 90 min of treatment (79.4 +/- 7.8 and 78.0 +/- 8.5, respectively). Morphologically, the exposed basal cells are attached to the basal lamina by hemidesmosomes and are similar to those in the intact animal.

[Diagnosis of subclinical hepatic encephalopathy: a parallel and comparative study between the evoked potentials and the performance psychometric tests]

The authors report the results of a parallel study between the three kinds of evoked potentials (EP) i.e. visual, brainstem auditory and somatosensory evoked potentials (VEP, BAEP and SEP) and psychometric tests in 30 posthepatitic cirrhotic patients. The results were compared with those from 20 peptic ulcer patients in healing stage. Psychometric tests were abnormal in 65.5% of the cirrhotic and in none of the peptic ulcer patients. The three kinds of evoked potentials were abnormal in 58.6% of the cirrhotic patients and in 5% of the peptic ulcer patients. The VEP, BAEP and SEP was abnormal in 13.3%, 10% and 50% of the cirrhotics respectively. The results of this study showed: of the three kinds of evoked potentials, SEP is the most sensitive one. The evoked potentials and the performance psychometric tests are complementary in the diagnosis of subclinical hepatic encephalopathy.

[Preoperative examination of patients with thyroid nodules by high-resolution real-time ultrasonography]

Fifty patients with thyroid nodules were examined by high-resolution real-time ultrasonography (US) before surgery. Of this series, the sonographic features of 54 nodules in 41 cases were classified according to internal echogenicity, cystic components, margin, sound transmission, anterior extra-thyroid extension, and peripheral "halo" sign. Except for the last, the differences between benign and malignant nodules were statistically significant (P < 0.05, P < 0.01 or P < 0.001). The comparisons of US and palpation examination (PE) with postoperative pathological findings were undertaken in these 50 cases, respectively. The sensitivity and accuracy for US were much higher than those for PE (sensitivity, 97% vs. 77%; accuracy, 97% vs. 76%). Our results show that by analyzing some sonographic characteristics, it may be possible to differentiate benign from malignant lesions and owing to its higher sensitivity and accuracy, ultrasonography is a better choice of the scrutiny into thyroidal gland.

Subzero nonfreezing storage of the mammalian cardiac explant. I. Methanol, ethanol, ethylene glycol, and propylene glycol as colligative cryoprotectants

We employed hyperosmotic concentrations of penetrating cryoprotective agents (CPA) to store the isolated rat hearts unfrozen at subzero temperatures. The effect of acute exposure to CPA was assessed by flushing the hearts with CP-14, a cardioplegic solution, containing methanol (MeOH), ethanol (EtOH), ethylene glycol (EG), or propylene glycol (PG) for 2 min and reperfusing immediately with Krebs-Henseleit buffer in a working-heart model. The maximal doses that did not cause irreversible suppression of heart function were: MeOH, 1.78 M; EtOH, 1.27 M; EG, 0.84 M; and PG, 0.87 M. For nonfreezing storage, the hearts were flushed with CP-14 containing the highest tolerable concentrations of MeOH, EtOH, EG, or PG, stored for 6 h at -3.7, -2.8, and -1.4 degrees C, respectively, and then reperfused. Control cardiac output (CO) was 76.2 +/- 1.8 ml/min. Post-reperfusional recovery of CO was 86% in MeOH hearts, 82% in EtOH hearts, 76% in EG hearts, and 79% in PG hearts. Thus MeOH offered not only the least cardiac-suppressing effect but the lowest nonfreezing storage temperature. When storage time was extended, recovery and myocardial ATP level decreased with time in hearts flushed with CP-14 + 1.78 M MeOH and stored at -3.7 degrees C. The decay of function was faster than the decay of ATP level, suggesting energy was better preserved than function. The low return of function, however, may be related to CPA toxicity, osmotic stress, and ischemia/reperfusion injury. Nonfreezing storage at subzero temperatures using these CPAs may provide a novel approach to long-term cardiac preservation.

A rabbit model for human cytomegalovirus-induced chorioretinal disease

AD169, a well-characterized laboratory strain of human cytomegalovirus (HCMV), was used to establish an animal model of progressive HCMV chorioretinal disease by injection of 10(5) pfu into the rabbit vitreous. Chorioretinal, vitreous, and pulmonary disease were monitored by HCMV recovery, clinical observation, antigen localization, and histopathology. Vitritis and focal areas of immune cellular infiltrates were seen in inner retinal layers on days 2-4 after inoculation. Disease progressed with more severe vitritis and to involve the outer retinal layers in areas of mixed monocytic cellular infiltrates, retinal destruction, choroidal edema, and congestion. HCMV was recovered from chorioretinal cell sonicate cultures in titers ranging from 10(4) to 10(5) pfu during peak disease, and HCMV antigens were detected focally by immunofluorescence in retinal layers on days 2 and 4 after inoculation. A rabbit model of HCMV chorioretinitis similar to human CMV disease allows investigation of HCMV pathogenesis and new antiviral therapies and evaluation of immune system modulation of the HCMV ocular infection.

Dual-wavelength frequency-stabilized CO(2) laser with four operating frequencies

A dual-wavelength frequency-stabilized CO(2) laser with a wideband dispersion cavity is described. A sequence of four operating frequencies can be composed on only one P-P line pair. The signature in this multifrequency CO(2) laser is unvaried and permanent. The frequency stabilities of simultaneous oscillations are approximately several parts in 10(10) (sample time 10 s).

Proton pumps populate the contractile vacuoles of Dictyostelium amoebae

Amoebae of the eukaryotic microorganism Dictyostelium discoideum were found to contain an interconnected array of tubules and cisternae whose membranes were studded with 15-nm-diameter "pegs." Comparison of the ultrastructure and freeze-fracture behavior of these pegs with similar structures found in other cells and tissues indicated that they were the head domains of vacuolar-type proton pumps. Supporting this identification, the pegs were observed to decorate and clump when broken amoebae were exposed to an antiserum against the B subunit of mammalian vacuolar H(+)-ATPase. The appearance of the peg-rich cisternae in quick-frozen amoebae depended on their osmotic environment: under hyperosmotic conditions, the cisternae were flat with many narrow tubular extensions, while under hypo-osmotic conditions the cisternae ranged from bulbous to spherical. In all cases, however, their contents deep etched like pure water. These properties indicated that the interconnected tubules and cisternae comprise the contractile vacuole system of Dictyostelium. Earlier studies had demonstrated that contractile vacuole membranes in Dictyostelium are extremely rich in calmodulin (Zhu, Q., and M. Clarke, 1992, J. Cell Biol. 118: 347-358). Light microscopic immunofluorescence confirmed that antibodies against the vacuolar proton pump colocalized with anti-calmodulin antibodies on these organelles. Time-lapse video recording of living amoebae imaged by interference-reflection microscopy, or by fluorescence microscopy after staining contractile vacuole membranes with potential-sensitive styryl dyes, revealed the extent and dynamic interrelationship of the cisternal and tubular elements in Dictyostelium's contractile vacuole system. The high density of proton pumps throughout its membranes suggests that the generation of a proton gradient is likely to be an important factor in the mechanism of fluid accumulation by contractile vacuoles.

Regulation of antibody responses: the role of complement and adhesion molecules

To analyze the importance of cell surface-associated molecules in modulating the immune response by facilitating T/B cell interaction, we used the T cell-dependent antigen, bacteriophage phi X174. Taking advantage of "experiments of nature", we studied specific antibody synthesis in patients with deficiencies of complement components or of the adhesion molecule CD11/CD18 (leukocyte adhesion defect, LAD) and guinea pigs and dogs with early complement component deficiency. Following intravenous injection of bacteriophage phi X174 into normal subjects or animals, a primary response consisting of IgM, a secondary response consisting of IgM and IgG, and a tertiary, predominantly IgG response can be distinguished. Patients and guinea pigs deficient of early complement component and LAD patients responded to repeated phage immunization with depressed antibody titers, lack of or inadequate amplification, and failure to switch from IgM to IgG, suggesting a defect in generating antigen-specific memory cells. Several mechanisms have to be considered: (i) The complement portion of the antigen-antibody complement complex facilitates the accumulation and trapping of antigen in lymphoid organs, thus improving the response to Ag at low concentrations. (ii) Immune complexes preferentially bind to antigen-specific B cells, cells expressing Fc receptors, or CR2 and CR3, the receptors for C3bi. (iii) The weak binding established between the MHC-II/Ag complex and the TCR complex is strengthened through the binding of several adhesion molecule pairs. (iv) Receptor-ligand binding initiates activation signals. The concept of binding/signaling via interacting molecules is further supported by the observation that mAb 60.3, recognizing the beta chain of CD11/CD18, blocks in vitro synthesis of antibody to bacteriophage by primed PBMC.

Environmental effects on the folding of functional peptide segments from steroid hormone receptors

Recent improvements in circular dichroism (CD) instrumentation now allow investigators to obtain highly reliable and reproducible CD spectra in the far-UV range to near 180 nm. These advances, coupled with new computer software for spectral interpretation, allow accurate calculations of secondary structural content in proteins and polypeptides. CD is particularly reliable for the calculation of alpha-helical content. We have utilized these features to determine the propensity of alpha-helix formation in highly purified synthetic peptides corresponding to segments from proteins. We obtain CD spectra of the peptides in 90% 2,2,2-trifluoroethanol (90% TFE; an alpha-helix promoting solvent) and in 2 mM sodium dodecyl sulfate (2 mM SDS; a beta-sheet promoting solvent) to assess helix stability in these different chemical environments. Using this methodology, we demonstrate that a peptide corresponding to a biologically active segment of the human estrogen receptor forms a stable alpha-helix in both environments. In contrast, peptide segments of equal length from other steroid receptors are alpha-helical in TFE but not in 2 mM SDS. These results show that the conformation of a peptide is a function of both its amino acid sequence and the local chemical environment.

Calmodulin and the contractile vacuole complex in mitotic cells of Dictyostelium discoideum

In amoebae of the eukaryotic microorganism Dictyostelium discoideum, calmodulin is greatly enriched on membranes of the contractile vacuole complex, an osmoregulatory organelle. Antibodies specific for Dictyostelium calmodulin were used in the present study to immunolocalize the contractile vacuole complex in relation to the Golgi complex (detected with wheat germ agglutinin) and the microtubule organizing center (MTOC, detected with anti-tubulin antibodies). Cells were examined throughout the cell cycle. Double-staining experiments indicated that the contractile vacuole complex extended to the MTOC in interphase cells, usually, but not always, overlapping the Golgi complex. In metaphase and anaphase cells, the Golgi staining became diffuse, suggesting dispersal of Golgi membranes. In the same mitotic cells, anti-calmodulin antibodies labeled numerous small cortical vacuoles, indicating that the contractile vacuole complex had also become dispersed. When living mitotic cells were examined, the small cortical vacuoles were seen to be active, implying that all parts of the Dictyostelium contractile vacuole complex possess the ability to accumulate fluid and fuse with the plasma membrane. In contrast to observations reported for other types of cells, anti-calmodulin antibodies did not label the mitotic spindle in Dictyostelium. Despite this difference in localization, it is possible that vacuole-associated calmodulin in Dictyostelium cells and spindle-associated calmodulin in larger eukaryotic cells might perform a similar function, namely, regulating calcium levels.

Organization of cytokeratin intermediate filaments in basal cells of growing rat trachea

The basal cell in airway epithelium plays a major role in attachment of ciliated and nonciliated columnar cells to the basal lamina. As the airway grows in diameter and the columnar epithelium in height, the number of basal cells and the amount of tonofilaments (cytokeratin filaments) and anchoring junctions increase. In this way they maintain a constant attachment strength between the increased volume of the epithelium and the basal lamina. The purpose of this study was to determine which cytokeratins (CKs) are expressed in growing basal cells of the rat and demonstrate where they are localized in the cytoskeleton. Sprague Dawley rats 10, 30 and 90 days of age were used in this study. For light microscopy, tracheal samples were fixed in 95% alcohol or 4% formalin for 2 hr and then embedded in paraffin. For electron microscopy, the tracheal samples were placed in 20 mM EDTA in HBSS media minus Ca++ and Mg++ at pH 7.4 for 60 min to permeabilize the cells and expose the intracellular structures. Antibodies to cytokeratins 7, 8, 10, 13 and 18 did not react to basal cells at any age studied. Antibodies to CKs 5 + 8, 14, 16 + 13, and 19 gave a positive reaction with basal cells at each age studied. Immunogold particles representing antibodies to CK 14 were heavily distributed over intermediate filaments making up the cytoskeleton. Both CK 16 + 13 and 19 were also over intermediate filaments but at a much lower density.(ABSTRACT TRUNCATED AT 250 WORDS)