Inoculation of plasmids expressing the dengue-2 envelope gene elicit neutralizing antibodies in mice

To develop a nucleic acid vaccine against dengue type-2 virus, the PreM and 92% of the envelope (E) genes were cloned into different eukaryotic plasmid expression vectors (pkCMVint Polyli and pVR1012). The resultant plasmid constructs (pD2ME and P1012D2ME) properly expressed the truncated E protein in vitro as evidenced by the expected protein size on SDS-PAGE and the ability of the protein to be recognized by monoclonal antibodies directed against conformational epitopes. Three-week-old BALB/c mice were given intradermal inoculations of each construct. Plasmid expression vectors without dengue genes were used as controls. One hundred percent of the mice that received the pD2ME and p1012D2ME constructs developed anti-dengue antibodies. These antibodies were shown to neutralize dengue type-2 virus in vitro. This is the first demonstration of the use of nucleic acid inoculation in the development of potential dengue virus. vaccines.

Melanoma in children and adolescents

Melanoma is a life-threatening and rare malignancy in childhood and adolescence. Because it is so uncommon, melanoma may not be recognized readily or considered seriously in a differential diagnosis, resulting in delays in definitive treatment. We review melanoma occurring in 13 patients under 20 years of age who presented to a single tertiary care children's hospital. Five patients had nonmetastatic primary cutaneous melanoma, with Breslow thickness measurement ranging from 0.84 to 7.8 mm. Three patients had metastatic primary cutaneous melanoma, three had metastatic melanoma arising ina congenital giant nevus, and two had primary leptomeningeal melanoma. All of the patients were given definitive surgical treatment; some received adjunctive radiation therapy and chemotherapy. Overall 5-year survival rate was 40.0% for all cutaneous melanomas, which included 100% for clinical stage I disease, and 0% for clinical stage II and III disease. Both patients with primary leptomeningeal melanoma died an average of 6 months following diagnosis. Nonmetastatic primary cutaneous melanoma is a survivable disease if detected early and treated by surgical excision; metastatic and leptomeningeal disease were uniformly fatal. Types of melanoma, risk factors for melanoma, and the role of the dermatologist in primary prevention and detection are discussed.

Genomic analysis of Epstein-Barr virus in nasal and peripheral T-cell lymphoma: a comparison with nasopharyngeal carcinoma in an endemic area

The Epstein-Barr virus (EBV) is prevalent in nasal and peripheral T-cell lymphoma (NPTL) in Taiwan, where nasopharyngeal carcinoma (NPC) is endemic. In order to understand the pathogenesis of these two malignancies in this endemic area, genomic analysis of EBV in NPTL with comparison to NPC is important. We investigated the EBV subtype (types A and B), BamH-I "f" variant, and the Xho-I site mutant of the latent membrane protein-1 (LMP-1) gene in 19 cases of EBV-associated NPTL and in 30 cases of NPC. EBV DNA from three patients with infectious mononucleosis (IM) was simultaneously studied as representative of normal healthy carriers. Similar to NPC and IM, the EBV in NPTL was found to belong to the type A strain in the majority (18 of 19) of cases by analyzing the 3' divergence of EBNA-2 genes. The extra restriction enzyme site in the BamHI-F region ("f" variant) of EBV DNA was frequently (15 of 30) demonstrated in NPC, but only rarely (1 of 19) was it detected in NPTL and IM (0 of 3). The Xho-I site mutant of the LMP-1 gene previously characterized in Chinese NPC also prevailed in NPTL and IM with an identical nucleotide sequence. No correlation exists between the EBV subtype and its variants. In conclusion, type A EBV is prevalent in Taiwanese NPTL, a finding much distinct from the dominance of type B virus in nonendemic European patients. The EBV genomes in NPTL are closely similar to those in IM or normal healthy carriers, but are distinct from NPC for the infrequency of the "f" variant. The prevalence of the LMP-1 mutant in this endemic region suggests that this EBV strain may confer a growth advantage role in the pathogenesis of these EBV-associated diseases. The rarity of the "f" variant in NPTL and its high frequency in NPC may explain the differential tumorigenesis of different EBV strains.

IFN regulatory factor-1 gene transfer into an aggressive, nonimmunogenic sarcoma suppresses the malignant phenotype and enhances immunogenicity in syngeneic mice

IFN-gamma has a direct antitumor effect on many tumor cell lines mediated through the IFN-gammaR. One effect of IFN-gamma is to induce the nuclear transcription factor IFN regulatory factor-1 (IRF-1), which may function as a tumor suppressor. In this study, mouse IRF-1 cDNA under a high constitutive expression promoter was transfected into the highly aggressive, nonimmunogenic MCA 101 murine sarcoma. Clones were obtained by G418 selection and screened for IRF-1 mRNA expression by reverse transcriptase-PCR (RT-PCR). High expression clones had high levels of two MHC class I proteins (H-2Kb and H-2Db) on the cell surface that correlated with increased levels of class I mRNA by RT-PCR. Furthermore, these clones also had increased levels of MHC class II protein (I-Ab), which correlated with increased levels of one subunit of class II mRNA by RT-PCR. IRF-1-expressing clones had markedly diminished cell growth in vitro and decreased anchorage-independent growth in a soft agar assay. These clones also demonstrated markedly prolonged tumor latency and slowed growth in syngeneic C57BL/6 mice. IRF-1 gene-transfected cells had shortened tumor latency and formed faster growing tumors in gamma-irradiated immunodeficient mice compared with results in immunocompetent mice. Mice immunized with IRF-1-transfected cells were protected against subsequent challenge with IRF-1 transfected cells and also demonstrated greater tumor latency and slower tumor growth against subsequent challenge with untransfected cells compared with mice immunized with empty vector-transfected cells. These studies demonstrate a tumor suppressor effect of IRF-1, which acts in vivo through both partial reversion of the malignant phenotype and enhanced immune recognition and may play a role in the antitumor effects of IFN-gamma.

IFN regulatory factor-1 gene transfer into an aggressive, nonimmunogenic sarcoma suppresses the malignant phenotype and enhances immunogenicity in syngeneic mice

IFN-gamma has a direct antitumor effect on many tumor cell lines mediated through the IFN-gammaR. One effect of IFN-gamma is to induce the nuclear transcription factor IFN regulatory factor-1 (IRF-1), which may function as a tumor suppressor. In this study, mouse IRF-1 cDNA under a high constitutive expression promoter was transfected into the highly aggressive, nonimmunogenic MCA 101 murine sarcoma. Clones were obtained by G418 selection and screened for IRF-1 mRNA expression by reverse transcriptase-PCR (RT-PCR). High expression clones had high levels of two MHC class I proteins (H-2Kb and H-2Db) on the cell surface that correlated with increased levels of class I mRNA by RT-PCR. Furthermore, these clones also had increased levels of MHC class II protein (I-Ab), which correlated with increased levels of one subunit of class II mRNA by RT-PCR. IRF-1-expressing clones had markedly diminished cell growth in vitro and decreased anchorage-independent growth in a soft agar assay. These clones also demonstrated markedly prolonged tumor latency and slowed growth in syngeneic C57BL/6 mice. IRF-1 gene-transfected cells had shortened tumor latency and formed faster growing tumors in gamma-irradiated immunodeficient mice compared with results in immunocompetent mice. Mice immunized with IRF-1-transfected cells were protected against subsequent challenge with IRF-1 transfected cells and also demonstrated greater tumor latency and slower tumor growth against subsequent challenge with untransfected cells compared with mice immunized with empty vector-transfected cells. These studies demonstrate a tumor suppressor effect of IRF-1, which acts in vivo through both partial reversion of the malignant phenotype and enhanced immune recognition and may play a role in the antitumor effects of IFN-gamma.

Emergency use of extracorporeal membrane oxygenation in a patient with post-cardiotomy myocardial stunning

Myocardial stunning refers to reversible postischemic myocardial dysfunction persisting after reperfusion. We report a patient who presented with biventricular failure, but exhibited neither definite electrocardiographic change nor elevation of serum cardiac enzyme levels in the post-cardiotomy period. The presentation was indicative of myocardial stunning. The patient's hemodynamics could not be maintained even with infusion of high doses of catecholamines. Extracorporeal membrane oxygenation successfully restored myocardial function. In conclusion, when the hemodynamic status of a patient with myocardial stunning cannot be maintained with inotropic agents, extracorporeal membrane oxygenation should be considered.

Genomic analysis of Epstein-Barr virus in nasal and peripheral T-cell lymphoma: a comparison with nasopharyngeal carcinoma in an endemic area

The Epstein-Barr virus (EBV) is prevalent in nasal and peripheral T-cell lymphoma (NPTL) in Taiwan, where nasopharyngeal carcinoma (NPC) is endemic. In order to understand the pathogenesis of these two malignancies in this endemic area, genomic analysis of EBV in NPTL with comparison to NPC is important. We investigated the EBV subtype (types A and B), BamH-I "f" variant, and the Xho-I site mutant of the latent membrane protein-1 (LMP-1) gene in 19 cases of EBV-associated NPTL and in 30 cases of NPC. EBV DNA from three patients with infectious mononucleosis (IM) was simultaneously studied as representative of normal healthy carriers. Similar to NPC and IM, the EBV in NPTL was found to belong to the type A strain in the majority (18 of 19) of cases by analyzing the 3' divergence of EBNA-2 genes. The extra restriction enzyme site in the BamHI-F region ("f" variant) of EBV DNA was frequently (15 of 30) demonstrated in NPC, but only rarely (1 of 19) was it detected in NPTL and IM (0 of 3). The Xho-I site mutant of the LMP-1 gene previously characterized in Chinese NPC also prevailed in NPTL and IM with an identical nucleotide sequence. No correlation exists between the EBV subtype and its variants. In conclusion, type A EBV is prevalent in Taiwanese NPTL, a finding much distinct from the dominance of type B virus in nonendemic European patients. The EBV genomes in NPTL are closely similar to those in IM or normal healthy carriers, but are distinct from NPC for the infrequency of the "f" variant. The prevalence of the LMP-1 mutant in this endemic region suggests that this EBV strain may confer a growth advantage role in the pathogenesis of these EBV-associated diseases. The rarity of the "f" variant in NPTL and its high frequency in NPC may explain the differential tumorigenesis of different EBV strains.

Probing the mechanism of action of Bacillus thuringiensis insecticidal proteins by site-directed mutagenesis--a minireview

The current model of the mechanism of action of several Bacillus thuringiensis insecticidal crystal proteins (Cry) is reviewed and tested by site-directed mutagenesis experiments. Amino acid (aa) residues were substituted in each of the three domains of Cry toxins and the effects on toxin stability, binding to receptors, irreversible insertion into the membrane, and ion channel activity were examined. Mutant proteins with aa altered on the putative membrane-proximal surface of domain I are affected in insertion into the membrane and toxicity, but not in binding to the receptor. Alterations in the putative receptor-binding loops of domain II show an effect on the initial (reversible) binding to the receptor when certain aa are altered, while affecting irreversible binding when other aa are altered. Mutant proteins with aa altered in a conserved track of aa of domain III have altered ion channel properties, as measured by the voltage clamping of insect midguts and the K+ permeability of brush border membrane vesicles. In summary, domain I is involved in insertion into the membrane and affects ion channel function, domain II is involved in receptor binding and insertion into the membrane, and domain III is involved ion channel function, receptor binding, and insertion into the membrane.

Optical and digital techniques for enhancing radiographic anatomy for identification of human remains

Out of a total of more than 300 radiographic identifications made by one of us (JJF), there were 11 cases in which radiologic adjuncts were used because the antemortem radiographs were either miniaturized or because anatomical landmarks could not be clearly discerned. The techniques used included slide projection (two cases), photographic enlargement and enhancement (two cases), digitization (three cases), and digitization with computer enhancement (three cases), commercial digitization (one case). In a 12th case, where identification was made by comparison of antemortem and postmortem film X-rays, the films were digitized as a further evaluation of a commercial system. This is the first reported use of these techniques.

The epidemiology of dengue virus infection among urban, jungle, and rural populations in the Amazon region of Peru

The first confirmed outbreak of dengue fever in Peru occurred during 1990 in Iquitos, a city of approximately 300,000 residents in the Amazon region. Because of the apparent establishment of endemic transmission of this mosquito-borne viral disease following the outbreak, epidemiologic studies were initiated in 1992. Blood specimens and data on demographic, environmental, and medical history factors were collected from volunteers in an urban sector of Iquitos, in a rural area on the outskirts of Iquitos, and in three nearby jungle communities. A follow-up blood specimen was obtained approximately one year later from a sample of subjects. Sera were tested for dengue IgG antibody by an enzyme-linked immunosorbent assay, and specificity was verified using a plaque-reduction neutralization test. Dengue antibody prevalence was 66% in the urban population, 26% in the rural population, and 32-67% in the three jungle areas. A significant association was found between age and antibody prevalence, with a steady increase in prevalence from 18% among subjects less than five years of age to greater than 90% for subjects more than 50 years old. Increased antibody prevalence also was associated with urban and jungle residence and with a piped source of household drinking water. Seroconversions were documented in four of five surveyed communities. These results indicate that dengue virus transmission continues in and around Iquitos and suggest that transmission also occurred prior to the 1990 epidemic.

Functional significance of loops in the receptor binding domain of Bacillus thuringiensis CryIIIA delta-endotoxin

Analysis of the three surface loops in domain II of Bacillus thuringiensis CryIIIA delta-endotoxin has been carried out to assess their role in receptor binding and toxicity. Site-directed mutagenesis was used to convert loop residues to alanine and the mutant proteins were analyzed for structural stability, toxicity to beetle larvae (Tenebrio molitor), binding to receptors on T. molitor brush border membrane vesicles (Tm-BBMV) and insertion into BBMV, as measured by irreversible membrane receptor binding. This study demonstrates the functional significance of loops for binding and insertion. Alanine replacements in loop I resulted in disruption of receptor binding or structural instability. The double mutation, Y350A, Y351A, could be suppressed by replacing a nearby R345 with alanine, and the resultant mutant protein also showed reduced receptor binding. Substitution of N353 and D354 in loop I with alanine residues caused the loss of binding ability and toxicity. A loop II double mutant, P412A, S413A, had no effect on binding or toxicity. A block mutation of loop III residues to alanine had the effect of reducing receptor binding while concomitantly increasing toxicity by 2.4-fold. We compared this up-mutant to wild-type toxin in each step of physiological processing of protoxin: solubility, proteolytic activation, and insertion into the Tm-BBMV. The loop III block mutant showed increased membrane insertion, but was similar to wild-type toxin in other parameters. These results reveal that loop I and loop III in domain II of CryIIIA delta-endotoxin are involved in receptor binding. In addition, the direct correlation between toxicity and irreversible binding of the loop III block mutant (despite the indirect relationship to reversible binding) suggests that loop III may play a role in membrane insertion.

Cyclic variation of Doppler power from whole blood under pulsatile flow

The echogenicity and Doppler power from whole blood under pulsatile flow have been found to vary during the flow cycle in previous studies both in vitro and in vivo. The present study was undertaken to better understand this phenomenon. Doppler power from whole blood under pulsatile flow was measured with a pulsed Doppler flowmeter as a function of the flow cycle, radial position and compliance of the vessel in a mock flow loop. It was found that the cyclic variation is more pronounced if the stroke rate is less than 56 beats/min and that the peak of the Doppler power from whole blood flowing near the center stream coincided with the peak of the flow velocity. However, it began to lead the velocity peak as the measurement site was moved away from the center stream. The lead increased as the radial distance was increased. The results also show that the compliance of the vessel can affect, to a certain extent, the magnitude of the cyclic variation. Results from intravascular Doppler measurements rule out the possibility that the cyclic variation is primarily due to the variation in attenuation caused by vessel wall during a flow cycle.

Detection and sequence analysis of a new herpesvirus-like agent in AIDS and non-AIDS Kaposi's sarcoma in Taiwan

A new herpesvirus-like DNA sequence (KSHV) has been recently identified in Kaposi's sarcoma from acquired immunodeficiency syndrome (AIDS) and non-AIDS patients. In order to verify the role of this new viral agent in Taiwan, a series of Kaposi's sarcoma specimens obtained from AIDS and non-AIDS patients in three medical centers representing different geographic locations of Taiwan were surveyed. A total of seven specimens from AIDS patients and 22 specimens from non-AIDS patients were tested for the presence of this herpesvirus-like agent by polymerase chain reaction (PCR) using the published Kaposi's sarcoma 330-233 primers. The tumor DNA was also tested for cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human herpes-virus type 6 (HHV-6). The Kaposi's sarcoma specimens from AIDS and non-AIDS patients were positive for KSHV except in one case. Only occasional specimens were positive for CMV and EBV, with a slightly higher positive rate for HHV-6 in AIDS and non-AIDS patients. Cloning and sequence analysis of the PCR products from two cases of Kaposi's sarcoma (one each for AIDS and non-AIDS) revealed only minor differences in this DNA sequence, as compared with the published data from north America. These results further support the assumption that this new KSHV is strongly associated with Kaposi's sarcoma in AIDS and non-AIDS patients in Taiwan.

Detection of an Epstein-Barr-virus variant in T-cell-lymphoma tissues identical to the distinct strain observed in nasopharyngeal carcinoma in the Taiwanese population

An EBV variant has been identified in NPC tissues in Taiwan. This EBV variant contains a point mutation in exon I of the LMP I gene. This mutation results in the loss of an XhoI site at nt 169,426, which is present in strain B95-8. In addition, this variant contains a 30-bp deletion in exon 3 of the gene. The recent demonstration of the prevalence of EBV-containing nasal and peripheral T-cell lymphoma in this region drove us to evaluate the presence of this NPC-EBV strain in 7 cases of T-cell lymphoma, as well as in 48 NPC tissues, 2 cases of Hodgkin's disease and I B-cell lymphoma. Four samples of normal lymph node tissue, 40 of normal nasopharynx tissue and 78 throat washings of healthy individuals were included for comparison. We used sequence-specific primers and the polymerase chain reaction (PCR) method to amplify LMP I gene fragments containing these variations. Mutations were then confirmed by restriction-enzyme digestion and the DNA sequencing analysis. Our results showed that 57 of 58 tumor-tissues samples were EBV-positive. Among them, 56, including 6 T-cell-lymphoma samples, belonged to the NPC strain. This strain of EBV was also present in 92% of EBV-positive normal nasopharynx tissues and in 84% of EBV-positive throat washings of the healthy individuals tested. These results suggest that the NPC-EBV strain is prominently present in Taiwan.

Evaluation of the severe combined immunodeficient (SCID) mouse as an animal model for dengue viral infection

Severe combined immunodeficient (SCID) mice reconstituted with human peripheral blood lymphocytes (hu-PBL) were evaluated as an animal model for demonstrating dengue (DEN) viral infection. Reconstituted mice (hu-PBL-SCID) that demonstrated successful engraftment by the presence of serum titers of human immunoglobulin (Ig) were inoculated intraperitoneally with DEN virus serotype 1 (DEN-1). Serial blood samples were taken postinoculation and assayed for virus in C6/36 cells. The identity of all viral isolates was confirmed by an immunofluorescence antibody assay using DEN-1 monoclonal antibody. A total of six experiments were performed using different procedures of reconstitution and infection, and in three of these experiments, DEN-1 virus was recovered from the hu-PBL-SCID mice. In the first successful experiment, DEN-1 virus was recovered on postinoculation day (PID) 24 from blood, spleen, thymus, and lung tissues of one of eight hu-PBL-SCID mice. A second group of eight hu-PBL-SCID mice were inoculated with human monocytes infected in vitro with DEN-1 virus. Virus was recovered from the blood of mice between PID 15 and 23, and from lung tissue of one of these mice. In a third experiment, seven SCID mice were treated initially with anti-asialo GM1 antibody to eliminate natural killer cells, and then were injected simultaneously with a mixture of hu-PBL and DEN-1 virus. Virus was demonstrated in the blood of one mouse on PID 38, and in another mouse on PID 8, 12, 20, 24, and 36.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of the alpha 2-subunit of laminin correlates with increased cell adhesion and metastatic propensity

Previous studies have indicated that laminin from neoplastic cells of high tumorigenicity is less active in promoting cell adhesion than aminin from normal cells or tissues. In the present study, we tested the hypothesis that laminin of metastatic tumor cells differs from that of nonmetastatic cells. Accordingly, we determined the subunit composition of laminin in highly metastatic, ras-transformed cells (4R) and compared it with laminin produced by nonmetastatic cells transformed with ras plus E1a (RE4). Metastatic 4R cells produced three to four times more of the alpha 2-subunit of laminin than RE4 cells did. Furthermore, the highly metastatic human melanoma cells (1205 and A2058) made and secreted into the medium, laminin containing significantly more of the alpha 2-subunit than laminin from the highly tumorigenic but nonmetastatic melanoma WM793 or HT1080 fibrosarcoma cells. Using HT1080 cells, laminin (250 ng/well) from 4R cells showed more adhesion promoting activity (68%) than laminin from RE4 cells (39%). Similarly, laminin isolated from human placenta, which expresses both the alpha 1 beta 1 gamma 1 and alpha 2 beta 1 gamma 1 isoforms, promoted cell adhesion better (63%) than EHS laminin (26%), which contains only the former isoform, at 250 ng/well. In addition, both 4R and RE4 cells attached more efficiently to 4R laminin-coated substratum than to RE4 laminin at 0.3 and 0.6 microgram/well.(ABSTRACT TRUNCATED AT 250 WORDS)

Chemical and bioactive constituents from Zanthoxylum simulans

Two new benzo[c]phenanthridine alkaloids, 6-methyldihydrochelerythrine [1] and 6-methylnorchelerythrine [2], together with 23 known compounds, were isolated from the root bark of Zanthoxylum simulans. Structures were elucidated by spectral analysis. Among them, the pyranoquinoline alkaloids, zanthosimuline [3], and huajiaosimuline [4], exhibited cytotoxic activity. In addition, compound 4 showed significant antiplatelet aggregation activity and induced terminal differentiation with cultured HL-60 cells.

Inhibition of collagen-induced platelet aggregation and adhesion by a pseudocyanide derivative of avicine isolated from Zanthoxylum integrifoliolum Merr

Avicine pseudocyanide, a derivative of avicine isolated from Zanthoxylum integrifoliolum Merr., inhibited collagen-induced platelet aggregation and release reaction in a concentration-dependent manner. Trimucytin is a collagen-like snake venom protein isolated from Trimeresurus mucrosquamatus. Avicine pseudocyanide also inhibited trimucytin (1 microgram/mL)-induced platelet aggregation and release reaction concentration dependently. The IC50 values of avicine pseudocyanide on collagen (10 micrograms/mL)- and trimucytin (1 microgram/mL)-induced platelet aggregation were 47.3 +/- 4.1 and 62.5 +/- 5.6 microM, respectively. Avicine pseudocyanide at a concentration of 300 microM inhibited less than 30% of platelet aggregation induced by ADP (20 microM), AA (100 microM), U46619 (1 microM), PAF (2 ng/mL) and thrombin (0.1 U/mL). The concentration-response curve of collagen-induced platelet aggregation was shifted to the right by avicine pseudocyanide (20-100 microM) concentration dependently. The Schild plot showed that pA2 and pA10 values of avicine pseudocyanide were 4.8 and 4.3, respectively, with slope of -1.9. Avicine pseudocyanide also inhibited collagen (10 micrograms/mL)-induced aggregation of rabbit whole blood with an IC50 of 145 +/- 13 microM. Collagen-induced thromboxane B2 formation was also inhibited by avicine pseudocyanide in a concentration-dependent manner with a maximal effect at 100 microM. However, arachidonic acid (AA)-induced thromboxane B2 and prostaglandin D2 formations were only partially suppressed by a high concentration of avicine pseudocyanide (300 microM). Avicine pseudocyanide (100 microM) inhibited the [3H]inositol monophosphate formation and the rise of intracellular Ca2+ concentration caused by collagen but not those caused by AA, U46619, platelet-activating factor and thrombin. In the presence of prostaglandin E1, Mg(2+)-dependent platelet adhesion to collagen was inhibited by avicine pseudocyanide with an IC50 of 278 +/- 16 microM. These data indicate that avicine pseudocyanide is an inhibitor of collagen-induced platelet aggregation and platelet-collagen adhesion.

Changes in renin activity, aldosterone level and electrolytes in pregnancy-induced hypertension

In order to observe the sequential changes in the renin-angiotensin-aldosterone system (RAAS) in hypertensive pregnancies, blood and urine samples of pregnant women were collected every four weeks from the 20th week of gestation to the fourth week after delivery in a consecutive and prospective study. Nine subjects developed pregnancy-induced hypertension in later gestation, and six of them with proteinuria were classified as having preeclampsia. The gestational ages at the onset of hypertension were the 28th week for one patient, the 32nd week for three patients and the 36th week for five patients. Plasma renin activity in most of the cases decreased to non-pregnant levels after hypertension was established, while the plasma aldosterone level did not. Marked variations in daily sodium and potassium excretion were observed at the various gestational weeks, while serum concentrations of these electrolytes changed only within a narrow range. No correlation between the changes in RAAS and electrolytes were shown in our cases.

[Evaluation of the apical seal of endodontically treated teeth by the ion-diffusion method]

It is generally accepted that improper preparation of the post space in endodontically treated teeth may damage sealing of the filling and cause treatment failure. Conventional method of detecting the sealing ability of endodontically treated teeth are quite complicated and inconvenient. To avoid the shortcomings of these traditional methods, the law of diffusion was adopted in this experimental design, and the results were compared with those of the traditional dye penetration method. Fifty sound molar teeth were treated by routine endodontic procedures, and were instrumented to 35# endodontic file. In 20 teeth in the control group, half were treated as a positive control by leaving the apical foramen open, and the remaining half were used as a negative control by sealing the foramen with two layers of nail polish. The other 30 experimental teeth were filled with gutta-percha points and sealer Canals by the lateral condensation method. Two weeks later, the filling material was removed to apical 3 mm, then 60 microL 2915 mM KCl solution was placed into the pulp cavity. The root was immersed into 1 mL 24.17 mM KCl solution. During the following 30 days, the concentration of the potassium ions in the outer solution was monitored by an ion-selective electrode. Finally, all 50 teeth were immersed in 1% methylene blue for 24 hours, sectioned with Isomet, and the extent of dye penetration was measured under a stereomicroscope with a digital caliper. The results of both methods were compared by means of regression analysis. There was a good correlation between the dye penetration method and the newly designed ion-diffusion method (r = 0.812).(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of immunoglobulin A in urine specimens from children with Campylobacter-associated diarrhea by a chemiluminescent indicator-based western immunoblot assay

A Western blot (immunoblot) assay was used to detect Campylobacter-specific immunoglobulin A in urine. Acute-phase urine samples from six children with Campylobacter diarrhea had titers ranging from 2 to 8. The highest titer was detected 4 days postonset. Campylobacter-specific immunoglobulin A was undetectable in the paired convalescent-phase specimens and urine samples from three control children.

Species of copper and zinc in sediments collected from the antarctic ocean and the Taiwan Erhjin Chi coastal area

The species of copper and zinc, such as bioexchangeable, skeletal, easily reducible (Fe and Mn oxides), moderately reducible (crystalline Mn oxide), organic combined with sulfides, and detritus with minerals, in mud and sand, separated from the surface Antarctic Ocean and the Taiwan Erhjin Chi coastal (including river and estuarine) sediments, have been analyzed by sequential leaching methods. Results show that in the Antarctic Ocean sediments, high concentrations of total copper (128 mg/kg) and zinc (458 mg/kg) were found in the high mud (99.09%) content samples compared with the low concentrations of total copper (83.8 mg/kg) and zinc (288 mg/kg) in low mud (51.69%) content samples. High concentrations of copper, zinc, manganese and iron are possibly due to the characteristics of manganese nodules, in which the species of copper and zinc are mainly contained in the crystalline Mn oxide phase. In the Taiwan Erhjin Chi coastal sediments, the total copper and zinc concentrations in mud and sand vary with season and location. High values were generally observed in the river sediments during the dry season, and low values were in the estuarine and coastal sediments during the heavy rainy season. High percentages of copper (as high as 49.4%) and zinc (as high as 76.7%) in mud and sand were in the bioexchangeable phase including the skeletal phase. This result might be correlated with the problems arising from human impact on copper and zinc as well as sewage pollution in Taiwan. In the organic combined phase, biogenic particulate matter related to higher primary productivity in the Antarctic Ocean is also discussed.

Adhesion promoting property of laminin from normal tissue and from a tumorigenic cell line

The cell adhesion promoting activity of laminin isolated from normal human placenta was compared with that isolated from mouse EHS tumor and from the cultures of a mouse epithelial cell line B82 and its tumorigenic derivative, B82HT. The adhesion promoting properties of commercial merosin isolated from placenta was also compared with the above preparations using the human fibrosarcoma HT1080 cells. Percent attachment was defined as (radioactivity extracted from attached cells)/(radioactivity in cells added to assay) x 100. HT1080 cells adhered more efficiently on laminin (0.5 micrograms/well), isolated from the B82 rather than B82HT cell conditioned medium, (82% vs 64%). Percent attachment of HT1080 cells on isolated native placental laminin or commercial merosin was significantly higher compared to laminin from the EHS tumor (at 0.75 micrograms/well, 69%, 73% and 20% respectively). In parallel experiments the steady-state levels of mRNAs for subunits A, M, B1 and B2 in cultures of B82 and B82HT cells were determined. The ratio of mRNA for the laminin subunits in B82 and B82HT cells was 1:0.9 for the A chain, 1:0.6 for the M chain, 1:0.4 for the B1 chain, and 1:0.3 for the B2 chain. Protein studies indicated that the M subunit is absent in laminin preparations from the EHS tumor whereas it is abundant in the laminin from placenta and in commercial merosin. Laminin isolated from B82 cells contains a higher proportion of the M subunit compared to that from B82HT cells. The data suggest that there are functional differences between the laminin found in normal tissue and that present in a solid tumor. Functional differences were noted between the laminins synthesized by the B82 cell line and its tumorigenic counterpart, B82HT. These differences may result from the lack of gene expression for the laminin subunit M by the EHS tumor and by the lower degree of gene expression for this subunit by B82HT cells. The possibility that the laminin synthesized by the tumorigenic cell line may be structurally different from that synthesized by the B82 cells should also be considered.

Plasma renin activity, aldosterone level, serum and urinary electrolytes in normal pregnant women aged 35 and older

Plasma renin activity (PRA), the plasma aldosterone (PA) level, and serum and urinary electrolytes were measured in 39 elderly pregnant women of greater than or equal to 35 (Group 1) and in 60 pregnant women less than 35 (Group 2) every four weeks from the 20th week of gestation to the fourth week postpartum. The PRA and PA levels increased in both groups. The PA levels increased after the 20th week and reached a peak at the 32nd week of gestation, while PRA decreased after the 20th week of gestation. This dissociation was observed in both groups. Daily urinary sodium excretion in Group 1 was higher than that of Group 2, while daily potassium excretion was not different between the two groups. Higher aldosterone secretion was observed after the 20th week of pregnancy in Group 1. It is concluded that pregnancy in older women is associated with higher sodium excretion and aldosterone secretion.