Adiabatic polymer-glass-waveguide all-optical switch

We propose an adiabatic all-optical switch that is composed of an asymmetric Y-branch ion-exchanged glass waveguide with a strip of nonlinear polymer loaded on top of one branch. The properties of nonlinear wave propagation in the device are investigated in detail. By extending the effective-index method to the analysis of nonlinear waveguides, we calculate the nonlinear dispersion curves in successive sections to explain the evolution of normal modes in the device. As the multivalued propagation constants exist in the tapered directional coupler region, the device possesses an abrupt switching behavior and nonreciprocal properties. To demonstrate nonlinear switching behaviors in the Y-branch waveguide further, we employ a beam propagation method to simulate optical-field propagation. The inputs by three different ports are investigated, and the results agree well with the dispersion-curve analysis.

Evidence for Monophyly and Arthropod Affinity of Cambrian Giant Predators

The Chinese Early Cambrian Chengjiang fauna includes three different anomalocaridids, a globally spread, extinct marine group including the largest known Cambrian animals. Anomalocaridids were active predators, and their presence implies that a complex ecosystem appeared abruptly in the earliest Phanerozoic. Complete specimens display several sets of characters shared only with some other exclusively Cambrian forms. This evidence indicates that anomalocaridids, Opabinia, and Kerygmachela form a monophyletic clade. Certain features indicate arthropod affinities of the lade, and for this group an unnamed (sub)phylum-level taxon within an arthropod (super)phylum is proposed.

Burst fracture of the fifth lumbar vertebra with unilateral facet dislocation: case report

A case of a burst fracture in conjunction with a facet dislocation of the fifth lumbar vertebra in a 15-year-old boy is reported. The patient was treated with open reduction and stabilization of L4 to S1 with a reduction-fixation stabilization system and placement of a Taylor-Knight brace. At 1-year follow-up examination the fusion was solid and the boy had resumed full activities.

The dimerization interfaces formed between the DNA binding domains of RXR, RAR and TR determine the binding specificity and polarity of the full-length receptors to direct repeats

Heterodimers of retinoid X receptor (RXR) and retinoic acid receptor (RAR) bind preferentially to directly repeated elements with spacing of two (DR2) or five (DR5) base pairs, due to the specific heterocooperative interaction of their DNA binding domains (DBDs) on these elements. We have demonstrated in the accompanying paper that the heterodimeric DBD interface that is responsible for the cooperative binding to DR5 elements, specifically involves the D-box of the RXR CII finger and the tip of the RAR CI finger. We show here that a second type of dimerization interface, which specifically implicates the RAR T-box and the RXR CII finger to the exclusion of the D-box, determines the selective binding to DR2 elements. Interestingly, the same type of dimerization interface (RXR T-box and CII finger) is responsible for the cooperative binding of homodimers of the RXR DBD to DR1 elements. Based on the three-dimensional structure of the glucocorticoid receptor DBD, modeling of RXR/RAR, RXR/TR and RXR/RXR DBD cooperative interactions predicts that in all cases the DBD contributing the CII finger, i.e. that of RXR, has to be positioned 5' to its cooperatively bound partner. This binding polarity of the DBDs is conferred upon the full-length receptors, since crosslinking experiments indicate that RXR is always 5' to RAR in complexes between either DR5 or DR2 and RXR/RAR heterodimers. The possible significance of these observations for transactivation by retinoic acid receptors is discussed.

Distinct regions of p53 have a differential role in transcriptional activation and repression functions

The wild type p53 tumor suppressor protein transactivates genes carrying p53 responsive elements and represses several TATA containing promoters. We report in vivo gene regulation assays where deletion of the N-terminal 75 residues (delta N75) results in loss of transactivation of p53CON and repression of an HPV 6 reporter. In contrast, removal of the C-terminal 75 (delta C75) amino acids resulted in a truncated protein capable of trans-activating p53CON but not able to repress the HPV 6 reporter. In vitro protein association assays revealed that the delta N75 protein, but not the delta C75 truncated protein, could oligomerize with the wild type p53 protein. Co-transfection assays with wild type p53 showed that the delta N75 mutant protein has a dominant negative effect on trans-activation function. However, it does not affect the ability of wild type p53 to repress transcription from the HPV 6 receptor. The delta C75 protein had no effect on the ability of the wild type p53 to activate p53CON or repress the HPV 6 reporter. These results suggest that distinct regions of p53 have a differential role in transcriptional activation and repression functions.

Analysis of integrated hepatitis B virus DNA and flanking cellular sequences in a childhood hepatocellular carcinoma

The DNA of tumor tissue K1 obtained at autopsy from a case of hepatocellular carcinoma (HCC) in a 9-year-old boy contained integrated hepatitis B virus (HBV) DNA at a single site in the chromosome (case 2, Chang et al.: Hepatology 13:316-320, 1991). To characterize further the integrated viral DNA sequences, a genomic library of the K1 DNA was constructed in the lambda L47.1 vector. One phage clone, designated KTM-1, containing integrated HBV DNA and cellular flanking sequences was obtained from this library. The restriction map and DNA sequence of this clone showed that the integrated HBV DNA was partially deleted and rearranged. The most conserved viral DNA sequences were surface and X genes and arranged in the opposite orientation. The viral core gene was not present. Using chloramphenicol acetyltransferase (CAT) assay, the C-terminal truncated X open reading frame was demonstrated to retain its trans-activating ability. The result suggested that the functional integrated X gene may play a role in hepatocarcinogenesis. The study also showed that the right cellular flanking sequences were human alphoid repetitive sequences.

[Measurements of the lumbar spinal canal of Chinese by computed tomography]

The study of the lumbar canal sizes in Chinese has not been reported before. Thirty adult patients, aged 20 to 40 years, who sustained thoracolumbar or lumbar fracture-dislocation and needed further computed tomographic (CT) scanning were included in this study. There was no significant back pain or sciatica on these patients before. Measurements of the med-sagittal anteroposterior (A-P) and interpedicular (I-P) diameters of the spinal canals L1 to L5 were requested at the same time during CT scanning. The results show that the lowest normal limits of the A-P and I-P diameters of the lumbar canals in Chinese are 11 mm and 19 mm respectively. The I-P diameters increase progressively from the first to the fifth vertebrae. The A-P diameters, however, are more variable and shortest at L2, L3 and L4 vertebrae.

[A report of the quantitative determination of relative afferent pupillary defect in central retinal vein occlusion]

Relative afferent pupillary defect (RAPD) indicates injury to the afferent pupillary nerve fibers anterior to the optic chiasma. The light attenuator composed of 2 optical polarizers was utilized to determine the RAPD quantitatively in 32 cases of central retinal vein occlusion (CRVO). In 13 cases with ischemic CRVO, 77% manifested an RAPD of 0.9 log unit or over and none less than 0.75 log unit. In contrast, among 19 cases with non-ischemic CRVO, 84% showed an RAPD of 0.65 log unit or less and none over 0.75 log unit, suggesting that RAPD was a sensitive index for differentiating ischemic from non-ischemic CRVO.

Functional analysis of the amino terminus of Epstein-Barr virus deoxyribonuclease

A cDNA coding for the Epstein-Barr virus (EBV) alkaline deoxyribonuclease (DNase) was expressed in Escherichia coli using the T7 phage system designed to allow expression of potentially lethal proteins. Induction of protein synthesis from the gene yielded a peptide with a molecular weight of approximately 52 kDa, consistent with the predicted open reading frame of EBV BGLF5. A high level of nuclease activity was detected in crude cell extracts, and the activity was neutralized by sera from nasopharyngeal carcinoma patients with high titers of anti-DNase antibodies. A series of deletion clones truncated at the amino or carboxyl terminus was constructed and expressed to define the regions responsible for the nuclease activity of EBV DNase. All the mutated molecules lost their activities even though their expression levels were comparable to that of the full-length DNase. To determine the exact role of the amino terminus of EBV DNase, mutants with small deletions were expressed. While three mutants with deletions of amino acid residues 11-30, 16-28, or 23-28 failed to show any detectable nuclease activities, one mutant in which the first 8 amino acids were replaced by the first 12 amino acid residues of the T7 major capsid protein contributed by the vector was enzymatically active. To further define the importance of the amino-terminal region, full-length DNase with point mutations was generated among residues 23-29 by site-directed mutagenesis and expressed in the same system. Assays of the DNase activity of these mutants revealed that the mutation of residue 29 was fully active, and mutations in 24-27 retained 50% activity. Nevertheless, the mutation at residue 23 resulted in a complete loss of activity and the mutation at residue 28 resulted in loss of 70% activity. These results suggest the biological importance of the amino terminus of the EBV DNase, especially residues 23-28.

Body mass and blood pressure in a lean population in southwestern China

Body mass has been consistently associated with blood pressure in acculturated populations but not in lean populations with low blood pressures. In southwestern China, in 1989, the authors studied the relation between body mass and blood pressure in three community-based random samples: rural Yi farmers (5,023 men, 3,218 women); Yi migrants (1,656 men, 919 women); and Han Chinese living in an urban setting (2,173 men, 1,516 women). The Yi farmers had virtually no obesity or hypertension and had little rise in blood pressure with age. The Yi migrants and Han had a steeper slope of blood pressure with age and consequently more hypertension. For men and women, respectively, mean body mass index (weight (kg)/height (m)2) was 20.6 and 21.0 in the Yi farmers, 21.3 and 21.4 in the Yi migrants, and 21.0 and 21.4 in the Han. Both systolic and diastolic blood pressure were positively related to body mass index in all six ethnicity-sex groups, and the association remained statistically significant after adjustment for age, heart rate, smoking, alcohol intake, and physical activity. The change in mean blood pressure for each kg/m2 increase in body mass index, after adjustment for community of residence, was 1.47 mmHg for systolic pressure and 1.13 mmHg for diastolic pressure. The association between body mass index and blood pressure was greater in men than in women and greater in Yi migrants and Han than in Yi farmers. The percentages of hypertension attributable to overweight (body mass index > or = 25) among the Yi farmers, Yi migrants, and Han, respectively, were 4.1%, 34.1%, and 24.0% for men and 0%, 26.2%, and 28.9% for women. Thus, even in this lean Chinese population with a low mean blood pressure, body mass was positively and independently associated with increased blood pressure.

Stability of HBV DNA in cell lines and nude mouse-passaged tissues derived from human hepatocellular carcinoma

Human hepatitis B virus (HBV) infection has been closely linked to the occurrence of hepatocellular carcinoma (HCC). Hepatoma cell lines and nude mouse-passaged hepatoma tissues were used in this report to study the HBV DNA status in these cells after passage. DNA was extracted from seven hepatoma cell lines and three nude mouse passaged HCC lines. Southern blot hybridization technique was performed with either cloned HBV whole genome or subgenomic DNA fragments as probes to analyze the presence of HBV DNA. Integration of HBV DNA fragments was detected in one mouse passaged tissue, R. Hybridization with HBV subgenomic DNA revealed that there were some DNA rearrangements of the integrated HBV DNA in R. However, the integrated HBV DNA could not be detected in the cell line derived from R after in vitro cultivation for 2 years. Both episomal form and integrated HBV DNA were detected in a cell line NTU-h3. Episomal form HBV DNA ih NTU-h3 changed after several passages. HBV DNA in NTU-h3 was unstable after in vitro cultivation. Therefore, we concluded that the presence of HBV DNA might not be essential for the maintenance of the tumorigenicity of hepatoma and the nude mouse system was more stable for maintaining HBV DNA in HCC.

Analysis of integrated hepatitis B virus DNA and flanking cellular sequences in the hepatocellular carcinoma cell line HCC36

A hepatocellular carcinoma cell line, HCC36, was established from an adult HBV carrier in Taiwan. From Southern blot analysis, there were at least four sites of integration of HBV DNA, and no viral replicative intermediates were detected. A genomic library was constructed from HCC36 DNA, and two phage clones, designated lambda 36A and lambda 36B, were shown to contain HBV DNA and flanking cellular sequences. In lambda 36A, HBV DNA sequences were quite conserved, and 7.4% base variation was detected. The viral sequences in lambda 36A and lambda 36B differed in only four bases, in addition to the microdeletion and -insertion observed in lambda 36B. The flanking cellular sequences identified in lambda 36A were human Alu sequences and in lambda 36B satellite sequences.

Effects of descending inhibitory systems on the c-Fos expression in the rat spinal cord during formalin-induced noxious stimulation

This study provides morphological evidence for the activation of the descending modulatory control by nociceptive afferent pathways. Fos-like immunoreactivity in the spinal dorsal horn is used as an indicator of efficacy of transmission of noxious inputs at this level. Wistar rats were anesthetized with nembutal and the spinal dorsolateral funiculus was transected unilaterally at the level of T11,12. Two days later, an equal volume (0.2 ml) of formalin (5% in saline) was injected into the plantar aspect of two hindpaws. After 1 h of injection, rats were deeply anesthetized and killed for the immunocytochemical examination of Fos-like protein product by using an immunocytochemical technique. The results show that the mean number of Fos protein-like immunoreactive neurons is significantly lower in the superficial laminae and in the neck of the dorsal horn on the side ipsilateral to the intact dorsolateral funiculus than that on the opposite side (i.e. 18.4 +/- 1.0 vs 30.0 +/- 1.3 and 33.9 +/- 0.2 vs 56.8 +/- 1.7, respectively). We conclude that the peripheral noxious inputs (which ascend via the ventral half of the spinal cord in this study) can activate the supraspinal descending inhibitory systems, which in turn suppress the synthesis of Fos-like protein in the related dorsal horn neurons.

Prediction of the development of neonatal hyperbilirubinemia in ABO incompatibility

BACKGROUND

ABO incompatibility is now the most common cause of isoimmune hemolytic disease of the newborn here. Although hemolytic disease because of ABO incompatibility is clinically milder than that from Rh incompatibility, severe hemolysis occasionally occurs, and some cases require exchange transfusion. It is desirable to assess the accuracy of a group of tests to predict the development of neonatal hyperbilirubinemia in ABO incompatibility. Then, early treatment is available for minimizing the frequency of exchange transfusion.

METHODS

Eighty-eight healthy full-term newborn infants born to blood group 0 mothers were studied and divided into four groups. Each baby weighed 2.5 Kg or more, had no evidence of G-6-PD deficiency. Group 1 consisted of 29 blood group A or B infants with hyperbilirubinemia (serum bilirubin levels > or = 15 mg/dl) and/or icterus praecox. Group 2 consisted of 24 blood group A or B infants without hyperbilirubinemia (serum bilirubin levels < 15 mg/dl). Group 3 consisted of 7 blood group 0 neonates with hyperbilirubinemia. Group 4 consisted of 28 blood group 0 neonates without hyperbilirubinemia. Titers of maternal IgG anti-A and anti-B antibodies were measured. Cord blood was used to performed direct Coombs' test and for bilirubin level determinations.

RESULTS

A total of 18 (62.1%) mothers had IgG anti-A or anti-B titers > or = 512X in Group 1. The majority of mothers (91.5%) in Group 2, 3 and 4 had anti-A or anti-B titers < or = 128X. Thirteen (44.8%) neonates in Group 1 had positive direct Coombs' test of the cord blood. Only one neonate (4.2%) in Group 2 and one neonate (3.6%) in Group 4 had positive direct Coombs' test. A total of 12 neonates (41.4%) in Group 1 had cord bilirubin levels > or = 4 mg/dl, whereas none in the other groups had cord bilirubin levels > or = 4 mg/dl.

CONCLUSIONS

ABO incompatible newborn infants with maternal IgG anti-A or anti-B titers > or = 512X, cord bilirubin levels > or = 4 mg/dl or positive direct Coombs' test of the cord blood represent a "high risk" category, and should be placed in hospital where frequent re-evaluation and appropriate therapy are available.

The patterns of binding of RAR, RXR and TR homo- and heterodimers to direct repeats are dictated by the binding specificites of the DNA binding domains

We show here that, in addition to generating an increase in DNA binding efficiency, heterodimerization of retinoid X receptor (RXR) with either retinoic acid receptor (RAR) or thyroid hormone receptor (TR) alters the binding site repertoires of RAR, RXR and TR homodimers. The binding site specificities of both homo- and heterodimers appear to be largely determined by their DNA binding domains (DBDs), and are dictated by (i) homocooperative DNA binding of the RXR DBD, (ii) heterocooperative DNA binding of RXR/RAR and RXR/TR DBDs, and (iii) steric hindrance. No homodimerization domain exists in the DBDs of TR and RAR. The dimerization function which is located in the ligand binding domain further stabilizes, but in general does not change, the repertoire dictated by the corresponding DBD(s). The binding repertoire can be further modified by the actual sequence of the binding site. We also provide evidence supporting the view that the cooperative binding of the RXR/RAR and RXR/TR DBDs to directly repeated elements is anisotropic, with interactions between the dimerization interfaces occurring only with RXR bound to the 5' located motif. This polarity, which appears to be maintained in the full-length receptor heterodimers, may constitute a novel parameter in promoter-specific transactivation.

Establishment and characterization of an HTLV-I cell line from a Taiwanese patient with HTLV-I-associated myelopathy

We describe a Taiwanese woman with chronic progressive myelopathy, in whom Western blot analysis of the serum and cerebrospinal fluid (CSF) displayed positive reactions to human T-lymphotropic virus type I (HTLV-I) proteins, p19, p24, p28, p36, gp46 and p53. HTLV-I proviral genomes were detected in the peripheral blood mononuclear cells (PBMC) and CSF cells by nested polymerase chain reaction and Southern blot hybridization. HTLV-I was successfully isolated from PBMC stimulated with interleukin-2 (IL-2). The established cell line, named THAM-1, was an IL-2-independent T-cell line with CD2+, CD3+, CD4+, CD25+ and HLA-DR+. Retrovirus particles with type C morphology were observed in the THAM-1 cells by electron microscopy, and HTLV-I-related antigens were also demonstrated by immunocytochemical staining and Western blot assay. Southern blot analysis revealed that HTLV-I proviral genomes were integrated into the THAM-1 cellular DNA. In Northern blot analysis, two extra-species of RNA were detected in addition to three typical viral transcripts. For the first time, an HTLV-I-producing T cell line was established from a patient with HTLV-I-associated myelopathy in Taiwan, an HTLV-I non-endemic area.

Use of bacterially-expressed antigen for detection of antibodies to the EBV-specific deoxyribonuclease in sera from patients with nasopharyngeal carcinoma

A cDNA clone, BG9, corresponding to the open reading frame BGLF5 of Epstein-Barr virus (EBV) DNase was inserted into an E. coli expression vector, pET3a, to generate a recombinant plasmid, pDNase 5. High level of expression of a DNase activity was detected in the E. coli transformed with pDNase 5 following induction with IPTG. The enzyme activity was purified using DEAE-cellulose, phosphocellulose and DNA-cellulose column chromatography. The purified protein appeared to be nearly homogeneous in SDS-PAGE using Coomassie blue staining. The requirement for divalent cations and optimum pH as well as inhibitory concentrations of ionic strength and polyamines for the purified enzyme activity were determined and seemed to be very similar to those of the enzyme activity purified from an EBV producing lymphoblastoid cell line. Using the purified enzyme as an antigen and anti-IgA as the secondary antibody, 82% (64/78) and 91% (71/78) of sera from patients with nasopharyngeal carcinoma (NPC) were shown to be positive by dot immunobinding assay and ELISA, respectively. The results suggest that purified E. coli expressed EBV DNase may be useful for preparing specific test for large scale screening of patients with NPC.

Inhibition of glucosyltransferase activities of Streptococcus mutans by a monoclonal antibody to a subsequence peptide

Preliminary analysis indicated that a 19-amino-acid peptide sequence (435 to 453 of GtfC) within a highly conserved region of the glucosyltransferases of the cariogenic streptococci might be functionally important (J.-S. Chia, S.-W. Lin, T.-Y. Hsu, J.-Y. Chen, H.-W. Kwan, and C.-S. Yang, Infect. Immun. 61:1563-1566, 1993). To obtain antipeptide monoclonal antibodies (MAbs), the 19-amino-acid peptide was conjugated to bovine serum albumin and used as an antigen in BALB/c mice. Six immunoglobulin G-secreting hybridoma clones, CJSm18-S1 to -S6, specifically reacted with this peptide and with purified GtfC and GtfD but not with bovine serum albumin in an enzyme-linked immunosorbent assay. The concentrated hybridoma supernatant of all six MAbs inhibited GtfC enzymatic activity but failed to inhibit GtfD, although GtfD contains the same peptide sequence. Further analysis of a purified immunoglobulin G2b MAb from one of the clones, CJSm18-S3, confirmed that this MAb specifically inhibited GtfC enzymatic activity for insoluble-glucan synthesis in a dose-dependent manner. CJSm18-S3, even at high concentrations, had no effect on GtfD, which synthesizes water-soluble glucan exclusively. Furthermore, the in vitro sucrose-dependent adherence of Streptococcus mutans was also inhibited by CJSm18-S3 in a dose-dependent manner. Our results indicate that the peptide containing the N-terminal conserved region of glucosyltransferases is functionally important for both enzymatic activity and bacterial adherence.

Human lung cancer cell lines exhibit resistance to retinoic acid treatment

Retinoic acid (RA) and nuclear retinoic acid receptors (RARs) have been implicated in a variety of human malignancies including lung cancer, and RA has been proposed as a chemopreventive agent for bronchogenic carcinoma. Normal human tracheobronchial epithelial cells show dramatic induction of RAR-beta mRNA and significant growth inhibition after RA treatment. In contrast, 17 of 22 small cell lung cancer (SCLC) and 9 of 15 non-SCLC lines treated with 1 microM RA showed no significant growth inhibition. Of interest, 5 SCLC lines with high levels of myc gene family expression related to c-, N-, or L-myc gene amplification exhibited growth inhibition (28-87%), whereas 2 non-SCLC lines actually showed growth stimulation after treatment with 1 microM RA. The lines varied greatly in their constitutive expression of RAR-beta mRNA, and 15 of 20 SCLC and 8 of 15 non-SCLC lines failed to show RAR-beta mRNA induction after RA treatment. Six cell lines showed possible alterations in the coding region of RAR-beta by complementary DNA (cDNA)/polymerase chain reaction (PCR) analysis using primers common to the RAR-beta1,2,3 isoforms, since other regions would undergo cDNA/PCR amplification whereas the DNA binding domain would not. Nonetheless, no abnormal band shift patterns in cDNA amplified by PCR were found by single strand conformation polymorphism analysis covering all 1344 base pairs of the RAR-beta open reading frame. Finally, no abnormalities in RAR-alpha gene structure or expression were identified by Southern and Northern blot analysis, including lines with cytogenetic abnormalities of 17q21. We conclude that abnormalities of the RAR-beta system are common in human lung cancer cell lines.

Ethamsylate in the prevention of periventricular-intraventricular hemorrhage in premature infants

A random and controlled trial was conducted to evaluate the efficacy and safety of ethamsylate in the prevention of periventricular-intraventricular hemorrhage (PIVH) in premature infants. Between January 1990 and July 1992, 171 premature infants with a birth weight of < 1,751 g who displayed no PIVH on initial cranial ultrasound scan, performed within an hour of delivery, were randomly divided into two groups. Group 1 consisted of 86 premature infants with a mean birth weight of 1.4 +/- 0.5 kg and a mean gestational age of 30.1 +/- 2.4 weeks. The first dose of ethamsylate 12.5 mg/kg (0.1 mL/kg from 250 mg/2mL ampoules) was given to group 1 intravenously within an hour of delivery and was followed by doses at six-hourly intervals for four days (total dose 200 mg/kg). Group 2 consisted of 85 premature infants with mean birth weight of 1.4 +/- 0.3 kg and mean gestational age of 30.4 +/- 2.2 weeks. Group 2 received 0.1 mL/kg normal saline intravenously in a similar fashion as the ethamsylate-treated group. Cranial ultrasound examinations were performed on postnatal days one, two, three, five, seven and 14. The incidence of PIVH in the ethamsylate-treated group was 24/86 (27.9%) and 39/85 (45.9%) in the control group (p < 0.02). In addition, the incidence of severe PIVH in the ethamsylate-treated group was 9/86 (10.5%) and 20/85 (23.5%) in the control group (p < 0.05). No adverse effects were attributed to ethamsylate therapy in this study.

Alcohol use and blood pressure in an unacculturated society

Alcohol intake has been associated with higher blood pressure in acculturated populations but not in unacculturated societies. We performed a cross-sectional survey of a random community sample of 5023 male Yi rural farmers and 1656 Yi and 2173 Han men living in an urban setting. Average alcohol intake among drinkers was 36.4 g/d in Yi farmers, 56.5 g/d in Yi migrants, and 38.7 g/d in Han men. Age-adjusted mean diastolic blood pressure was 66.9, 70.5, and 71.7 mm Hg, respectively. Diastolic blood pressure was higher at higher alcohol intakes in all three groups (all P < .001). After adjustment for age, body mass index, heart rate, smoking, and physical activity, the change (95% confidence interval) in diastolic blood pressure for each standard drink was 0.50 (0.38-0.62), 0.31 (0.18-0.43), and 0.24 (0.07-0.40) mm Hg for Yi farmers, Yi migrants, and Han men, respectively. The percentage of variance in diastolic blood pressure explained by alcohol intake was 5% for Yi farmers, 4% for Yi migrants, and 2% for Han men. In a random sample of 831 men, these associations were independent of urinary sodium, potassium, calcium, and magnesium and sodium-potassium ratio. In the Yi farmers, associations were less strong for systolic blood pressure and no longer significant after adjustment. Approximately 33% of hypertension could be attributed to daily alcohol use in the Yi groups compared with 9.5% in the Han people.(ABSTRACT TRUNCATED AT 250 WORDS)

Heterogeneity of transcriptional activity of mutant p53 proteins and p53 DNA target sequences

Transcriptional activity of p53 was monitored by cotransfection of pCMV expression vectors containing wild-type and mutant p53 cDNAs into the p53-null H1299 lung cancer cells along with luciferase reporter plasmids containing different p53 target sequences in the 5' regulatory region: fragment A of the ribosomal gene cluster (RGC); p53 consensus sequence (p53CON); or a tandemly linked RGC+p53CON sequence. Our results show: (1) wild-type p53 stimulates the transcription of reporter genes with p53CON and RGC in their 5' region while most p53 mutants occurring in human cancers have lost this activity; (2) the R273H mutant retains transcriptional activity for the p53CON sequence but not RGC; (3) some mutants are temperature-sensitive for the transcriptional activity with the p53CON but not the RGC sequence; (4) p53 mutants vary in their ability to inhibit wild-type p53 transactivation but there is no difference between p53CON and RGC sequences; (5) lung cancer cells with endogenous mutant p53 proteins (M246I in H23 cells and R248L in H322 cells) retain transcriptional activity for the p53CON but not the RGC sequence. We conclude that p53 DNA target sequences vary in their response to mutant p53 proteins, and that p53 mutants vary in several transactivation related functions.

The induction and characterization of antiserum against human placenta 17-beta-hydroxysteroid dehydrogenase

17-beta-Hydroxysteroid dehydrogenase was purified from human placenta. The purification process included the following steps: 50% saturated ammonium sulfate precipitation; heat treatment; affinity column chromatography; and preparative SDS gel electrophoretic elution. This enzyme was also characterized by HPLC gel filtration and two dimensional gel electrophoresis with isoelectrofocusing. The results indicate that the molecular weight of these enzymes in their native condition is around 68 kDa and 34 kDa in SDS PAGE. Therefore, the active form of the enzyme is an identical dimmer in nature. There are three charged isomers as demonstrated by isoelectrofocusing. The antiserum against the 17-beta-HSD was induced by injection of purified human placenta 17-beta-HSD in rabbits. The antiserum was collected and characterized by ELISA, immunohistochemistry, immunoblot and immunoprecipitation tests. The results showed that the antibody titer was over 1:12,800, and specificity against human placenta 17-beta-HSD was also observed.

Agreement between overnight and 24-hour urinary cation excretions in southern Chinese men

Agreement between overnight and 24-hour urinary sodium, potassium, calcium, and magnesium excretion was studied in a sample of 63 normotensive Southwestern Chinese men: 30 Yi farmers and 33 urban residents in April 1989. Overnight (8-hour) and 24-hour urine specimens were collected on 3 consecutive days. Estimated correlation coefficients between 24-hour and overnight mean true values were 0.863 and 0.906 for sodium, 0.736 and 0.816 for potassium, 0.902 and 0.725 for calcium, and 0.733 and 0.703 for magnesium in Yi farmers and urban residents, respectively. Hourly overnight urinary sodium and potassium excretion rates were significantly lower than the corresponding hourly 24-hour urinary excretion rates: -0.60 and -1.99 mmol/hour for sodium, -1.24 and -0.48 mmol/hour for potassium (all p < 0.05) in Yi farmers and urban residents, respectively. In multiple regression analyses, the differences between 24-hour and overnight urinary sodium and potassium excretion rates were significantly and positively related to differences between 24-hour and overnight creatinine excretion rates. The ratios of intraindividual to interindividual variance were lower for 24-hour collections than for overnight collections for sodium and calcium, but the differences in these ratios for potassium and magnesium were small. For sodium and calcium, twice as many overnight as 24-hour collections were required to estimate the correlation between cations and blood pressure with the same accuracy; for potassium and magnesium, overnight and 24-hour collections were equally accurate. These results indicate that in normotensive populations such as the one studied, overnight urine collections may be used to estimate 24-hour cation excretion. The underestimate of cation excretion by assessments based on collection of overnight specimens may be due to either a lower creatinine clearance or a lower intake of cations at night.

[Primary hyperparathyroidism with parathyroid adenocarcinoma in a patient with Turner's syndrome complicated with thyrotoxicosis]

We report a rare case of Turner's syndrome coexisting with thyrotoxicosis and parathyroid adenocarcinoma resulting in hyperparathyroidism. This 45-year-old female patient presented with primary amenorrhea and poor development of secondary sexual characteristics. She also experienced repeated bone fractures, and body weight loss. Multiple risk factors of osteoporosis developed simultaneously in this patient. The interesting interactive relationship of hypercalcemia between thyrotoxicosis and primary hyperparathyroidism was noted. The best choice was surgery for both cases. Calcium supplements and various hormone replacements in addition to regular investigative radionuclide scans were required.

Abnormalities of sodium transport in non-insulin-dependent diabetes: association with renal disease

We investigated both sodium-lithium countertransport (Na-Li CT) and ouabain-sensitive sodium transport (Na pump) of erythrocytes in healthy subjects (group A), patients with non-insulin-dependent diabetes (NIDDM) without nephropathy (group B), patients in the proteinuric stage (group C), and those in the renal insufficiency stage (group D). Erythrocytes from all four groups had a similar initial water and ionic content and were loaded with similar degrees of Li and Na for efflux studies. There were no significant differences in erythrocyte Na-Li CT or Na pump among the four groups. However, the maximal rate of Na-Li CT was significantly higher in a group of subjects with essential hypertension when compared with groups A, B and C, consistent with the view that there is a genetic marker for essential hypertension. Ouabain-insensitive Na efflux (Na leak) of erythrocytes was found to be significantly higher in group D than in groups A or B. Also, a significant positive correlation existed between Na leak and urine protein levels of the subjects studied. Our results thus indicate that in contrast with insulin-dependent diabetic patients (IDDM) where an elevated Na-Li CT is observed, with diabetic nephropathy, Na-Li CT in NIDDM is apparently not associated with nephropathy; rather the ouabain-insensitive Na efflux appears to be correlated with the stages of nephropathy in NIDDM. The association suggests that the rate of ouabain-insensitive Na efflux may provide an index for assessing the degree of nephropathy in NIDDM patients.

Analysis of Epstein-Barr virus BamHI F DNA fragment in nude mouse-passaged nasopharyngeal carcinoma tissues

Two nude mouse-passaged nasopharyngeal carcinoma (NPC) tissues, NPC-295 and NPC-306, were different in ability to transform cord blood lymphocytes and contained Epstein-Barr virus (EBV) genomes with difference in BamHI F DNA fragment. Four clones containing DNA sequences of the BamHI F fragment (54,853-62,249) were obtained from genomic libraries of NPC-295 and NPC-306 and their partial restriction enzyme maps and sequences were determined. The restriction enzyme maps of EBV DNA at the BamHI F fragment in NPC-295 and NPC-306 appeared to be similar to that of EBV B95-8 strain. However, 8 nucleotide differences were revealed between NPC-295 and the B95-8 strain when 566 nucleotides (55,405-55,970) were compared, and 15 out of 677 nucleotides analyzed (55,410-56,086) were different between NPC-306 and B95-8.

Studies on pharmacokinetics of sulfonated aluminum phthalocyanine in a transplantable mouse tumor by in vivo fluorescence

The pharmacokinetic properties of sulfonated aluminum phthalocyanine (A1PCS) in mouse bearing transplantable S180 tumors were determined by an in vivo method. In vivo fluorescence measurements were made on the hind legs of mice, one leg bearing a tumor and the other, without a tumor, being used as a control. These in vivo data were compared with the results obtained from in vitro extraction fluorescence experiments. The results obtained by the two methods showed remarkable agreement, both procedures demonstrating that the concentration of A1PCS in the tumor was substantially higher than that in muscle. In both cases, the maximum tumor to muscle A1PCS concentration ratio occurred at 24-36 h after drug administration. The agreement between the in vivo and in vitro measurements shows that the in vivo fluorescence technique can be used successfully in pharmacokinetic studies of metallo-phthalocyanines in a superficial tumor model. The in vivo technique has the advantages of being rapid and convenient.

Sensation and experience of pain in children

The study explored children's self-assessment of the pain experience and to understood the relative factors that influence the words used to represent children's pain. Using an outline of a human figure and a section of the open questionnaire to study, 106 nine- to sixteen-year-old children marked their pain location using colors to represent pain. They rated the intensity and duration of their pain, and described their experience of pain (sensation, causes, and ways to manage pain). The results showed that children clearly described pain, that there were appreciable differences between feelings of headache, leg pain, backache, and shoulder pain with pain intensity and duration of pain; that explained the difference of occurrence of abdominal pain in cross effect between age and sex; that explained the difference of the occurrence of toothache in cross effect among triangle of hospitalized experience, age, and sex; that there was significant relationship between abdominal pain and family structure. For severe abdominal pain or toothache the children could ask doctors for pain relief. For the others, they could take medication or rest for their middle or mild abdominal pain. The ways to manage leg pain were injection and massage. Change of position was applied to relieve backache. From the children's self-reports, we understand that causes of children's pain were derived from bad sleep, food, decayed teeth, exercising, and hitting. Pain avoidance is best achieved by accident prevention, cultivation of good health habits, and integration of daily living skills.

Analysis of a DNA polymorphic region in the gtfB and gtfC genes of Streptococcus mutans

We have previously demonstrated the existence of DNA polymorphisms at the 5' coding regions of the gtfB and gtfC genes specifying the streptococcal glucosyltransferases (J.S. Chia, T.Y. Hsu, L.J. Teng, J.Y. Chen, L.J. Hahn, and C.S. Yang, Infect. Immun. 59:1656-1660, 1991). DNA sequence analysis by polymerase chain reaction and direct sequencing revealed that while several nucleotide changes were identified, accounting for the polymorphisms, the amino acids which they code for remain unchanged. The polymorphic region is located in a highly conserved amino terminus of the glucosyltransferases. A peptide of 19 amino acids from this region reversed the inhibiting activity of an antiserum raised against the proteins coded for by the gtfB and gtfC genes. The results suggest that the polymorphic region, varying in DNA but not in amino acid sequences, might specify some biological function.

Immunity and responses of circulating leukocytes and lymphocytes in monkeys to aerosolized staphylococcal enterotoxin B

Rhesus monkeys immunized intramuscularly or orally with staphylococcal enterotoxin B (SEB) toxoid or SEB toxoid incorporated in microspheres made of poly(DL-lactide-co-glycolide) were challenged with a lethal dose of aerosolized SEB to study their immunity and cellular responses in the circulation. It was found that circulating antibodies play a critical role in preventing SEB from triggering toxicosis. Monkeys with high levels of antibodies survived, while those with low levels underwent 2 to 3 days of toxicosis and died. Intramuscular immunization induced high levels and oral immunization induced low levels of antibodies. The circulating antibodies in surviving monkeys decreased dramatically within 20 min and started to rebound at 90 min after SEB challenge. At 90 min, the dying monkeys showed in the circulation a dramatic increase of polymorphonuclear leukocytes and decreases of NK cells and monocytes (CD16 and CD56 markers) as well as of lymphocytes with HLA-DR, CD2, CD8, and IL2R alpha (CD25) markers. The number of polymorphonuclear leukocytes showed an inverse correlation with the numbers of monocytes and various lymphocyte subpopulations which, except for IL-2R, CD16, and CD56(+) cells, showed a direct correlation with one another. The changes in the populations of leukocytes, monocytes, NK cells, and lymphocytes seem to be an indication of initial toxicosis; however, the roles of these cells in toxicosis and death remain to be defined.

Multiple parameters control the selectivity of nuclear receptors for their response elements. Selectivity and promiscuity in response element recognition by retinoic acid receptors and retinoid X receptors

A number of nuclear receptors are capable of binding to specific DNA sequences known as response elements that correspond to two 5'-PuG(G/T)TCA motifs. We have systematically compared the selectivity of DNA sequence recognition by the estrogen receptor and the retinoic acid receptor (RAR) and retinoid X receptor (RXR), using a variety of synthetic oligonucleotides related to natural response elements. The importance of the spacing and relative orientation of the PuG(G/T)TCA motifs as well as the possible role of the flanking sequences were investigated for each receptor. We find that the three receptors have different response element preferences and that their intrinsic DNA binding properties cannot be simply ascribed to spacing or orientation rules. For example, RARs bind with similar efficiencies to response elements containing directly repeated PuGTTCA motifs separated by 2, 3, 4, or 5 base pairs, and RXRs bind to response elements in which the directly repeated motifs are separated by 1, 2, and 5 base pairs. The actual sequence of the repeated motifs and the nature of their flanking bases appear to be important parameters in determining RAR and RXR binding efficiencies. The possibility that the binding specificity of nuclear receptors can be modified by interactions with other proteins, in particular other nuclear receptors, is discussed in relation to the patterns of transcriptional activation observed with either endogenous or transiently expressed receptors on chimeric promoters containing various response elements.

Renal calcification in very low birth weight infants

Between January 1990 and December 1991, serial real-time ultrasound examinations and analyses of urine were performed on a total of 50 infants with birth weights less than 1,500 g to assess the incidence of renal calcification. Five infants (10%) developed renal calcification at a mean age of 48.8 +/- 14.1 days. These 5 infants with renal calcification had significantly shorter gestations (28.2 +/- 0.8 vs. 30.1 +/- 1.7 weeks, p < 0.0005) and lower birth weights (934 +/- 45 vs. 1,311 +/- 188 g, p < 0.0005) when compared with infants without renal calcification. None of the affected infants were treated with furosemide. Affected infants had a mean urine volume of 85.8 +/- 11.3 ml/kg/24 h, mean urine calcium level of 5.07 +/- 1.18 mg/kg/24 h, mean urine calcium to creatinine (mg/mg) ratio of 0.67 +/- 0.09, and a mean urine N-acetyl-beta-D-glucosaminidase (NAG) to creatinine (U/g) ratio of 259 +/- 133. Urinalyses showed that affected infants had significantly higher urine pH values and hematuria. Alkaline phosphatase concentrations and initial parathyroid hormone levels were not different among the two groups. In summary, renal calcification occurred in 10% of very low birth weight infants and multiple risk factors seem to be contributory. The smaller, sicker and more immature infants appear to have increased risk for developing renal calcification.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous balloon mitral valvuloplasty for mitral stenosis with and without associated aortic regurgitation

Between November 1985 and December 1991, percutaneous balloon mitral valvuloplasty (PBMV) with the Inoue balloon catheter (Toray Marketing & Sales [America], Inc., New York, N.Y.) was performed in 53 patients with rheumatic mitral stenosis and associated mild to moderate aortic regurgitation. Mean left atrial pressure was 22.5 +/- 8.6 mm Hg and 9.7 +/- 5.5 mm Hg before and after PBMV, respectively (p < 0.001). The mean diastolic mitral gradient as determined by the catheter method decreased from 18.7 +/- 11.4 mm Hg to 2.1 +/- 3.1 mm Hg (p < 0.001). The echocardiographic mitral valve area was 1.0 +/- 0.2 cm2, 2.0 +/- 0.6 cm2, and 1.9 +/- 0.5 cm2, before and after PBMV and at follow-up (p < 0.001 before PBMV vs after PBMV and at follow-up). The mean diastolic mitral gradient as determined by two-dimensional and Doppler echocardiography was 19.3 +/- 8.4 mm Hg, 5.2 +/- 4.1 mm Hg, and 6.6 +/- 3.3 mm Hg, before and after PBMV and at follow-up, respectively (p < 0.001). The phonocardiographic interval between the Q wave and the mitral component of the first heart sound was 85.2 +/- 15.2 msec, 74.2 +/- 13.4 msec, and 72.3 +/- 15.7 msec before and after PBMV and at follow-up (p < 0.001 before PBMV vs after PBMV and at follow-up). The phonocardiographic interval between the aortic second sound and opening snap was 73.4 +/- 18.1 msec, 88.7 +/- 9.6 msec, and 92.1 +/- 11.7 msec before and after PBMV and at follow-up (p < 0.001 before PBMV vs after PBMV and at follow-up). The voltage of P loop in the frontal plane of the vectorcardiogram was 0.25 +/- 0.04 mV, 0.21 +/- 0.04 mV, and 0.20 +/- 0.03 mV before and after PBMV and at follow-up (p < 0.001 before PBMV vs after PBMV and at follow-up). The New York Heart Association classification improved from class II in 26 patients and class III in 27 patients before PBMV to class I in 48 patients and class II in five patients after PBMV. These hemodynamic, noninvasive, and clinical results were not significantly different from those that were obtained in 112 patients with mitral stenosis without associated aortic regurgitation, who were studied during the same period in our cardiac catheterization laboratory. It was concluded that patients with rheumatic mitral stenosis are suitable candidates for PBMV whether or not they have associated aortic regurgitation of mild to moderate degree.

Detection of Epstein-Barr virus genome in nasopharyngeal carcinoma by in situ DNA hybridization

To elucidate the possible role of Epstein-Barr virus (EBV) in nasopharyngeal carcinoma (NPC), we investigated the EBV genome in NPC by in situ DNA hybridization using radioisotope- and and biotin-labeled EBV DNA probes. The EBV genome was detected in the tumor cells in all (100%) 60 cases, irrespective of histological type, but not in the lymphocytes. Silver grains, which reflected the copy number of the EBV genome, were more abundant in the nonkeratinizing, spindle cell, and undifferentiated carcinomas than in keratinizing squamous cell carcinoma. In the keratinizing carcinoma, which was poorly differentiated in this series, the EBV genome was usually detected in anaplastic tumor cells, and not in the keratinizing areas. The sensitivity of the radioisotopic technique was superior to that of the biotinylated probe method (100 vs. 81.7%, p < 0.0003). These results suggest that EBV is etiologically related to nasopharyngeal carcinogenesis and that the differentiation of tumor cells in vivo, and probably also in vitro, may become incompatible with EBV replication.

Prophylaxis of ophthalmia neonatorum: comparison of silver nitrate, tetracycline, erythromycin and no prophylaxis

From November, 1989, to October, 1991, 4544 neonates were born at our hospital. Neonatal ocular prophylaxis immediately after birth was used with 1% tetracycline ophthalmic ointment in 1156 neonates, 0.5% erythromycin ophthalmic ointment in 1163 neonates and 1% silver nitrate drops in 1082 neonates. No prophylaxis for neonatal conjunctivitis was given to 1143 neonates. A total of 302 infants (6.7%) developed conjunctivitis during the first 4 weeks of life. Between December, 1991, and January, 1992, 425 neonates were born at our hospital and all were given 0.5% erythromycin ophthalmic ointment twice in the first 24 hours after birth for ocular prophylaxis. Thirty-one (7.3%) infants developed conjunctivitis during the neonatal period. The incidence rates of neonatal chlamydial conjuctivitis in the tetracycline, erythromycin, silver nitrate, no prophylaxis and erythromycin twice groups were 1.3, 1.5, 1.7, 1.6 and 1.4%, respectively. We conclude that neonatal ocular prophylaxis with erythromycin (one or two doses) or tetracycline or silver nitrate does not significantly reduce the incidence of neonatal chlamydial conjunctivitis compared with that in those given no prophylaxis.

Chemosensitivity of salivary gland and oral cancer cell lines

Chemosensitivity of salivary gland and oral cancer cell lines to 14 antitumor drugs was tested using a tetrazolium-based colorimetric assay and the relative antitumor activity (RAA) of the drugs was compared. Adriamycin (ADM), methotrexate and fluorouracil (5-FU) showed the most potent RAA against the cell lines while cantharidin did not. The rank orders of other 10 drugs against each cell line differed from each other.

Long-term results of percutaneous mitral valvuloplasty with the Inoue balloon catheter

The initial 85 patients who successfully underwent percutaneous mitral valvuloplasty (PMV) with the Inoue balloon catheter at the Guangdong Cardiovascular Institute between November 1985 and November 1988 had a mean follow-up period of 5 +/- 1 year (range 43 to 79 months). Before and after PMV and at follow-up, mean diastolic mitral gradients by the catheter method were 17.5 +/- 6.2, 3.1 +/- 3.3 and 3.3 +/- 3.4 mm Hg, respectively (p < 0.001 before vs after PMV and before vs follow-up; and p > 0.05 after PMV vs follow-up). Mean diastolic mitral gradients by the Doppler method were 18 +/- 6, 8 +/- 5 and 9 +/- 5 mm Hg, respectively (p < 0.001 before vs after PMV and before vs follow-up; and p > 0.05 after PMV vs follow-up). Mean diastolic mitral gradients by the Doppler method were 18 +/- 6, 8 +/- 5 and 9 +/- 5 mm Hg, respectively (p < 0.001 before vs after PMV and before vs follow-up; and p > 0.05 after PMV vs follow-up). Mitral valve areas by the echo-Doppler method were 1.1 +/- 0.3, 2.0 +/- 0.4 and 1.8 +/- 0.5 cm2, respectively (p < 0.001 before vs after PMV and before vs follow-up; and p > 0.05 after PMV vs follow-up). Phonocardiographic and vectorcardiographic studies, and cardiopulmonary exercise testing showed significant improvement after PMV and at follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of antigen expressed in bacteria for detection of EBV-specific thymidine kinase antibodies in sera from patients with nasopharyngeal carcinoma

Two cDNA clones covering the N- and C-terminal portions of the EBV BXLF1 open reading frame were selected from a cDNA library derived from P3HR1 cells. The two clones were ligated, the N-terminal untranslated region truncated, and the product inserted into an E. coli expression vector, pET3CP*. The fusion protein was expressed under control of the T7 phage phi 10 gene promoter and shown to possess thymidine kinase activity. The protein was then used as an antigen to detect antibody reactivities in serum samples of nasopharyngeal carcinoma patients and healthy blood donors. Using a 1:400 dilution of serum samples in Western blot analyses, it was possible to differentiate the reactivities of serum IgA of NPC patients and healthy donors. The prevalence of positive reactivity to EBV TK in NPC was around 84%. The test was compared to others used for early diagnosis of NPC and was able to detect some patients who were negative in those tests.

Antitumor activity of psoralen on mucoepidermoid carcinoma cell line MEC-1

Psoralen (PSO) was found cytotoxic against in vitro cultured human mucoepidermoid carcinoma cells of MEC-1 cell line. Its IC50 value was 8.6 micrograms/ml, and relative antitumor activity (RAA) 15. PSO suppressed DNA synthesis, damaged microvilli and cell membrane, and induced degeneration of mitochondria. It inhibited the growth of MEC-1 cells transplanted in nude mice by 79.1% which was as strong as pingyanmycin (PYM 81.4%). The body weight loss of PSO treated tumor-bearing mice was 5%, whereas that of PYM treated ones 13.3% (P < 0.01). PSO may be an effective agent for the treatment of human mucoepidermoid carcinoma.

Characterization and purification of human retinoic acid receptor-gamma 1 overexpressed in the baculovirus-insect cell system

The full-length cDNA for the human retinoic acid receptor-gamma 1 (RAR-gamma 1) has been expressed to high levels in Spodoptera frugiferda (Sf9) cells using the baculovirus expression system. Western blot analysis revealed that RAR-gamma 1 expression increased between 32 and 60 h post-infection. The recombinant receptor was expressed primarily as a nuclear protein and displayed a molecular mass of 50 kDa as determined by SDS/PAGE and gel-filtration chromatography, consistent with its cDNA-deduced size. Based on ligand binding, 2 x 10(6) RAR-gamma 1 molecules were expressed per Sf9 cell, a level approx. 2000 times greater than in mammalian cells. The receptor was partially purified 300-fold by sequential anion-exchange, gel-filtration and DNA affinity chromatographies. The overexpressed receptor specifically bound all-trans-retinoic acid (RA) and the synthetic retinoid CD367 with high affinity (Kd 0.15 nM and 0.23 nM respectively). The RA metabolites 4-hydroxy-RA and 4-oxo-RA were poor competitors for [3H]CD367 binding to recombinant RAR-gamma 1 (K(i) > 1 microM), indicating that 4-oxidation of RA greatly reduces its affinity for RAR-gamma 1. Gel-retardation analysis demonstrated that RAR-gamma 1 specifically bound the RA response element of the mouse RAR-beta gene. RAR-gamma 1 species expressed from recombinant baculovirus (in Sf9 cells) and vaccinia virus (in HeLa cells) exhibited similar affinities for RA and CD367 and had comparable DNA-binding properties in gel-retardation experiments. Moreover, a similar requirement for additional DNA-binding stimulatory factor(s) was observed in both cases. These results provide a basis for the use of baculovirus-expressed RAR-gamma 1 in further functional and structural studies.

Cloning and expression of a cDNA encoding the Epstein-Barr virus thymidine kinase gene

A clone of the Epstein-Barr virus (EBV) thymidine kinase (TK) gene was derived from a cDNA library of P3HR1 cells. The gene product was expressed as a fusion protein in a procaryotic system by using T7 RNA polymerase. The recombinant TK showed a molecular mass of 67 kDa and was biologically active. Antiserum raised in mice immunized with partially purified TK recognized an antigen present in EBV-superinfected Raji cells using an indirect immunofluorescence assay.

Maximum inspiratory pressure: a neonatal criterion for weaning from mechanical ventilation

Thirty-three newborn infants admitted to the neonatal intensive care unit of our hospital were studied. Mechanical ventilation was used for more than 24 hours for each patient. Maximum inspiratory pressure (MIP) was measured by means of a manometer at the oral end of the endotracheal tube just prior to extubation. Of the 33 studied neonates, 28 were successfully weaned at the first attempt of extubation (group I). Five neonates failed at the first attempt of extubation and required tracheal reintubation (group II). The mean birth weight was 1.78 +/- 0.86 kg, the mean gestational age was 32.6 +/- 4.3 weeks and the mean duration of intubation was 4.2 +/- 2.1 days in group I. The mean birth weight was 1.74 +/- 0.61 kg, the mean gestational age was 32.8 +/- 3.5 weeks and the mean duration of intubation was 7.0 +/- 2.6 days in group II. The mean MIP value in group I was -42.57 +/- 7.18 cm H2O and the mean MIP value in group II before the first attempt of extubation was -21.2 +/- 1.79 cm H2O. The patients in group I had a significantly lower MIP (P < 0.01) than group II, of the 28 patients in group I, 27 had MIP equal to or exceeding -35 cm H2O and only one case had MIP of -30 cm H2O. We conclude that measurement of MIP is a simple, useful and safe method for neonates to predict successful extubation from prolonged mechanical ventilation. A neonate with a MIP exceeding -35 cm H2O can be safely weaned from mechanical ventilation.

Synthesis of a biospecific adsorbent for the purification of the three human retinoic acid receptors by affinity chromatography

The total synthesis of an affinity gel suitable for the purification of retinoic acid receptors (hRARs) is reported. A chalcone derived from a potent retinobenzoic acid (Ch55) was chosen as the ligand and fixed to an immobilized matrix by coupling with the N-hydroxysuccinimide ester of agarose (Affi-Gel 10, Bio-Rad Laboratories). Efficiencies of purification of the different human RARs were tested, using recombinant receptors produced with the baculovirus expression system.

Detection of human herpesvirus-6 DNA by polymerase chain reaction in serum or plasma

Human herpesvirus-6 (HHV-6) is a newly identified human pathogen. Currently clinicians rely mainly on blood lymphocyte culture and serological tests to diagnose HHV-6 infection. The polymerase chain reaction (PCR) was carried out on the plasma or sera of patients to determine the value of PCR in the diagnosis of HHV-6 infection. A total of 30 patients entered the study; 10 were experiencing acute HHV-6 infections and 20 were healthy and served as controls. HHV-6 DNA was detected by PCR in the serum or plasma of the 10 cases with acute HHV-6 infections. All 20 controls had no HHV-6 DNA in their sera. The time for serum to become PCR-positive coincided with the appearance of IgG HHV-6 antibody. The relatively late presence of HHV-6 DNA in serum might result from late lysis of infected cells by immune responses. It is concluded that detection of HHV-6 DNA by PCR in the serum is a valuable tool for the diagnosis of acute and/or active viral infection.

A temperature-regulated, retrotransposon-like element from Candida albicans

A repetitive element was isolated from the genome of Candida albicans. This repetitive element, which we designated alpha, was localized to a 500-bp fragment of genomic DNA. The alpha element was dispersed in the genome and varied in copy number and genomic location in the strains examined. Analyses of various loci containing the alpha element identified a locus containing a composite element. This composite element consisted of two direct repeats of the alpha element separated by approximately 5.5 kb of DNA, a structural arrangement similar to that of retrovirus-like transposable elements. The flanking alpha elements of the composite structure were 388 bp in length and were identical in sequence. They were bounded by the nucleotides 5'-TG. ... CA-3', which were part of a delimiting inverted repeat, a feature conserved in the long terminal repeats of retroviruses and retrovirus-like elements. As in retrovirus-like elements, the entire composite element, including the alpha elements, was transcribed into an approximately unit-length mRNA. The expression of this transcript was greatly increased when cells were grown at 25 versus 37 degrees C. As has been found in many retrotransposons, the composite element was flanked by a 5-bp duplication and varied in both copy number and genomic location in various strains. We conclude that the composite element is a retrotransposon-like element, and we have designated this element Tca1. We suggest that Tca1 may be relevant to the genomic evolution of C. albicans and the pathogenic potential of the organism.

Phosphorylation of DARPP-32 and protein phosphatase inhibitor-1 in rat choroid plexus: regulation by factors other than dopamine

The molecular mechanisms underlying regulation of fluid production by secretory epithelia such as the choroid plexus are poorly understood. Two cAMP-regulated inhibitors of protein phosphatase-1, inhibitor-1 (I1) and a dopamine- and cAMP-regulated phosphoprotein, M(r) = 32,000 (DARPP-32), are enriched in the choroid plexus. We show here that these two phosphoproteins are colocalized in choroid plexus epithelial cells. We have developed a novel method for studying the phosphorylation state of DARPP-32 and I1 in intact cells, using a phosphorylation state-specific monoclonal antibody. Several drugs and hormones that are known to alter fluid secretion and that increase cAMP levels (forskolin, isoproterenol, vasoactive intestinal peptide) or cGMP levels (atrial natriuretic peptide) or that may use additional second messenger pathways (5-HT), increase the phosphorylation of I1 and DARPP-32 in rat choroid plexus. In contrast, dopamine does not alter cAMP and cGMP levels, or I1 and DARPP-32 phosphorylation. Our results indicate that DARPP-32, known to be regulated by dopamine in a number of tissues, can be phosphorylated in response to non-dopaminergic factors, including hormones acting through non-cAMP-dependent pathways. Our results also raise the possibility that inhibition of phosphatase-1, as a result of I1 and DARPP-32 phosphorylation, might be part of a final common pathway in the action of several factors that are known or thought to alter cerebrospinal fluid production.

Cytoplasmic and mitochondrial tRNA nucleotidyltransferase activities are derived from the same gene in the yeast Saccharomyces cerevisiae

ATP (CTP):tRNA-specific tRNA nucleotidyltransferase is an enzyme required for the synthesis of functional tRNAs in eukaryotic cells. Neither the tRNA genes in the nucleus nor in organelles encode the CCA end, so it must be added post-transcriptionally. The gene that codes for the enzyme that adds the CCA end to nuclear coded tRNAs in Saccharomyces cerevisiae has been isolated (Aebi, M., Kirchner, G., Chen, J.-Y., Vijayraghavan, U., Jacobson, A., Martin, N. C., and Abelson, J. (1990) J. Biol. Chem. 265, 16216-16220). We now demonstrate that there is a mitochondrial tRNA nucleotidyltransferase activity in yeast and that it is a matrix enzyme. A comparison of purified mitochondrial enzyme with its cytoplasmic counterpart revealed no differences. These results suggest that proteins responsible for this step in the maturation of tRNAs in the nucleus and mitochondria might be identical and coded by the same nuclear gene. Accumulation of shortened mitochondrial as well as cytoplasmic tRNAs in a strain with a temperature-sensitive tRNA nucleotidyltransferase is consistent with this hypothesis. Alteration of the wild type gene such that amino-terminal truncated proteins are produced leads to a defect in mitochondrial function and a decrease in mitochondrial nucleotidyltransferase activity. This provides a direct demonstration that one gene provides this enzyme activity for the biosynthesis of tRNAs in both the nuclear/cytoplasmic and mitochondrial compartments in yeast.