CD28-induced T cell activation. Evidence for a protein-tyrosine kinase signal transduction pathway

CD28 is a 44-kDa homodimeric receptor expressed on the majority of T cells. Engagement of the CD28 receptor by soluble anti-CD28 mAb in conjunction with PMA causes the induction of lymphokine/cytokine production and proliferation in resting T cells via signal transduction pathways independent of the TCR. The precise nature of the biochemical events that occur after perturbation of the CD28 receptor remain unclear. We report evidence for the coupling of CD28 to a protein-tyrosine kinase pathway. Multivalent cross-linking of the CD28 receptor or stimulation by soluble CD28 mAb plus PMA, but not PMA or soluble CD28 mAb alone, reproducibly caused the rapid (within 2 min) tyrosine phosphorylation of a 100-kDa cellular substrate. In some experiments, additional cellular substrates of 110, 85, 74, 68, 56, 43, and 29 kDa were also observed. The tyrosine phosphorylation of these substrates was completely inhibited by 12 h pretreatment of T cells with herbimycin A, a selective inhibitor of src-family protein-tyrosine kinases. Pretreatment of T cells with herbimycin was without effect on CD28 surface expression but did inhibit CD28 mAb plus PMA-induced IL-2 mRNA levels, IL-2R(CD25) up-regulation, and cell proliferation. The inhibition of IL-2 mRNA levels was likely at the level of transcription, because herbimycin inhibited NF-AT, AP-1, and CD28RC but not NF-kappa B or OCT-1 binding activities to their respective IL-2 enhancer region sequences. Herbimycin did not inhibit PMA-dependent events including CD69 surface expression, NF-kappa B nuclear binding activity or the level of CD25 induced by PMA alone, supporting the notion that herbimycin is acting to inhibit a CD28 initiated or regulated protein-tyrosine kinase pathway(s).

Comparative ultrastructure of the tip of ventricular papillary muscle

Electron microscopic studies of the tips of left ventricular papillary muscles from seven human, two monkey, three sheep, and two chicken hearts were done to elucidate the fine structure of myotendinous junctions. The human specimens were from normal hearts obtained 3 to 9 hours postmortem from persons aged 7 months to 30 years (mean, 13.3 years). We found no significant ultrastructural differences between the human hearts and those of monkey, sheep, and chicken. Myocardial fibers were elongated and thinner (tapered) in the tips of papillary muscles. In addition to usual working myocardial cells, the distal end of narrowing muscle fibers also contained small pale cardiocytes containing fewer myofibrils and smaller mitochondria. These cells were similar to P cells or transitional cells in the conduction system. Nerve axons and Schwann cells were commonly seen in the interstitium, usually in association with capillaries. Fibroblasts and axon varicosities were occasionally seen extremely close to the cardiocytes. These specialized myocardial cells associated with rich neural tissue in the papillary muscle tip possibly function as foci of local automaticity. This histologic organization may also represent neurosensory function responding to and monitoring local pressure changes, efferent adrenergic or cholinergic neural activity, or both.

Cholecystokinin at physiological levels evokes pancreatic enzyme secretion via a cholinergic pathway

The mechanism by which physiological concentrations of cholecystokinin (CCK) evoke pancreatic exocrine secretion in humans was investigated. CCK octapeptide (CCK-8) dose dependently increased trypsin and lipase output in healthy humans. Atropine inhibited CCK-8 (10 ng.kg-1.h-1)-stimulated trypsin output by 84.0 +/- 7.7% and lipase output by 78.6 +/- 9.2%. The inhibition with atropine was much less with a CCK-8 dose of 40 ng.kg-1.h-1 (41.8 +/- 6.6% for trypsin and 46.3 +/- 7.3% for lipase). CCK-8 at 10 ng.kg-1.h-1 produced plasma CCK levels similar to postprandial levels (6.0 +/- 1.3 vs. 6.9 +/- 0.8 pM), whereas the 40-ng.kg-1.h-1 dose produced supraphysiological levels (18.4 +/- 3.1 pM). To evaluate if CCK might act via stimulation of cholinergic nerves, in vitro studies were performed using rat pancreas. CCK-8 (10 nM-10 microM) stimulated [3H]acetylcholine release from pancreatic lobules that was blocked by tetrodotoxin, a calcium-free medium, and the CCK antagonist L364,718. In conclusion, CCK-stimulated pancreatic enzyme secretion is dependent on cholinergic neural and noncholinergic pathways. In humans, CCK infusions, which produce plasma CCK levels similar to those seen postprandially, stimulate the pancreas predominantly via a pathway dependent on cholinergic innervation. Correlative in vitro experiments suggest that CCK may act by stimulation of neural acetylcholine release. In contrast, supraphysiological CCK infusions act in part via noncholinergic pathways.

CD28-induced T cell activation. Evidence for a protein-tyrosine kinase signal transduction pathway

CD28 is a 44-kDa homodimeric receptor expressed on the majority of T cells. Engagement of the CD28 receptor by soluble anti-CD28 mAb in conjunction with PMA causes the induction of lymphokine/cytokine production and proliferation in resting T cells via signal transduction pathways independent of the TCR. The precise nature of the biochemical events that occur after perturbation of the CD28 receptor remain unclear. We report evidence for the coupling of CD28 to a protein-tyrosine kinase pathway. Multivalent cross-linking of the CD28 receptor or stimulation by soluble CD28 mAb plus PMA, but not PMA or soluble CD28 mAb alone, reproducibly caused the rapid (within 2 min) tyrosine phosphorylation of a 100-kDa cellular substrate. In some experiments, additional cellular substrates of 110, 85, 74, 68, 56, 43, and 29 kDa were also observed. The tyrosine phosphorylation of these substrates was completely inhibited by 12 h pretreatment of T cells with herbimycin A, a selective inhibitor of src-family protein-tyrosine kinases. Pretreatment of T cells with herbimycin was without effect on CD28 surface expression but did inhibit CD28 mAb plus PMA-induced IL-2 mRNA levels, IL-2R(CD25) up-regulation, and cell proliferation. The inhibition of IL-2 mRNA levels was likely at the level of transcription, because herbimycin inhibited NF-AT, AP-1, and CD28RC but not NF-kappa B or OCT-1 binding activities to their respective IL-2 enhancer region sequences. Herbimycin did not inhibit PMA-dependent events including CD69 surface expression, NF-kappa B nuclear binding activity or the level of CD25 induced by PMA alone, supporting the notion that herbimycin is acting to inhibit a CD28 initiated or regulated protein-tyrosine kinase pathway(s).

A cross-cultural assessment of perceived health problems in the elderly

To study cross-cultural differences in perceived health problems in the elderly the Nottingham Health Profile (NHP) developed by Hunt et al. was administered to subjects from the People's Republic of China and Australia. The Australian stratum was further categorized according to cardiovascular status. Analyses of covariance (with age as the covariate) on each of the six subscales of the NHP yielded significant differences for 'Energy', 'Pain', 'Emotional reactions', 'Social isolation' and 'Physical mobility'. No differences were found for the 'Sleep' subscale. Through comparisons between the mean scores for the four strata and from normative data it is concluded that it is likely that the NHP is 'culture free' on the dimensions 'Energy', 'Pain', 'Emotional reactions', 'Social isolation' and 'Physical mobility'.

Anterior-posterior and rotational displacement of the tibia elicited by quadriceps contraction

The anterior-posterior displacement and rotation of the tibia elicited by isolated loading of the quadriceps muscle was determined as a function of joint angle and muscle load using a computerized radiographic technique. Data collected from 12 fresh-frozen cadaveric knees demonstrated that quadriceps contraction can result in significant (less than 7 mm) anterior displacement of the tibia in the range of 0 degrees to 80 degrees of flexion, and a mild (less than 2 mm) posterior displacement in the range of 80 degrees to 120 degrees of flexion. Peak anterior displacement of 6.3 mm was observed at 30 degrees of flexion under a 12 kg load in the quadriceps, while a constant 1.5 mm posterior displacement was observed throughout flexion angles exceeding 80 degrees. It was further shown that the magnitude of the anterior displacement increased nonlinearly as the quadriceps force increased. Loading of the quadriceps also resulted in internal rotation of the tibia in the range of 0 degrees to 90 degrees of flexion, and in external rotation of the tibia in the range of 90 degrees to 120 degrees. Peak internal rotation of 7 degrees was observed at 15 degrees of flexion and a peak external rotation of 1 degrees was detected at 120 degrees of flexion. Larger quadriceps load resulted in larger rotation. We concluded that quadriceps contraction during knee extension has direct impact on anterior displacement and rotation of the tibia and therefore on anterior cruciate ligament stress, increasing it as the muscle's force is increased during knee extension.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma vitamin B12 level as a potential cofactor in studies of human immunodeficiency virus type 1-related cognitive changes

Studies of cognitive function in subjects with human immunodeficiency virus type 1 (HIV-1) infection who remain relatively asymptomatic (ie, Centers for Disease Control stages II and III) have provided widely variable estimates of cognitive impairment. In view of the finding that approximately 25% of asymptomatic HIV-1-infected subjects demonstrate either marginal or overt vitamin B12 deficiency, we have investigated plasma vitamin B12 status as a potential cofactor in studies of HIV-1-related cognitive impairment. When cognition was assessed in asymptomatic (Centers for Disease Control stages II and III) HIV-1-infected participants taking into consideration vitamin B12 status, those subjects with low plasma vitamin B12 levels (less than 180 pmol/L) performed more poorly than did those with normal (greater than or equal to 180 pmol/L) vitamin B12 status on specific measures of information processing speed and visuospatial problem-solving skills. These findings suggest that concurrent vitamin B12 deficiency may be a cofactor in subtle cognitive changes observed in the asymptomatic stages of HIV-1 infection. These differences in prevalence of low plasma vitamin B12 levels may help to explain differences among studies in the proportion of HIV-1-infected subjects showing cognitive impairment.

Real-time parallel optical logic operation using photorefractive two-wave mixing and fringe-shifting techniques

The coupling effect between phase and intensity in photorefractive two-wave mixing in a Bi(12)SiO(20) crystal is demonstrated. By using interference fringe-shifting techniques that are executed by a Mach-Zehnder interferometer, an optical parallel logic operation system that is based on the coupling effect is implemented.

Hepatitis C infection in a pediatric dialysis population

A variable prevalence of hepatitis C (HCV) infection has been reported in adult patients on hemodialysis. We have studied HCV infection and associated risk factors in a pediatric dialysis unit. Sera from all 27 patients undergoing either hemodialysis or peritoneal dialysis in our unit were tested for antibody to HCV by enzyme-linked immunosorbent assay, and seropositives were confirmed by recombinant immunoblot assay. Records were reviewed for demographic, biochemical, and risk factor data. From the total of 27 patients (12 male, mean age 20.9 years, range 7.3 to 28.1 years), five were anti-HCV(+) (18.5%). All the anti-HCV(+) patients had been on hemodialysis (69 to 194 months, mean 105 months), while of the 22 anti-HCV(-) patients, only 14 had been on hemodialysis (5 to 209 months, mean 41.4 months), P less than .005. All the anti-HCV(+) patients had received blood transfusions (10 to 124 units, mean 61.4 units) as had 12 of the anti-HCV(-) patients (1 to 54 units, mean 14 units), P less than .02. Of the 5 anti-HCV(+) patients, only one had prior hepatitis B infection; of the 22 anti-HCV(-) patients, three had hepatitis B surface antigen, and no others had evidence of hepatitis B infection. The most predictive risk factor for HCV infection was length of time on hemodialysis. Eleven of the 27 patients (40.7%) had abnormal alanine aminotransferase values, of whom four were anti-HCV(+), three were hepatitis B surface antigen(+), and one was seropositive for antibody to human immunodeficiency virus.(ABSTRACT TRUNCATED AT 250 WORDS)

Clonal heterogeneity of synovial fluid T lymphocytes in inflammatory synovitis

Several studies have examined patients with rheumatoid arthritis for the presence of oligoclonal populations of synovial T lymphocytes. The results of these studies have been conflicting. In this study one patient with rheumatoid arthritis and two with other forms of inflammatory synovitis were examined by Southern blot analysis of T cell clones generated from synovial fluid by primary limiting dilution. Evidence of oligoclonality was documented only in a patient with psoriatic arthritis. The distinguishing characteristics of this patient, in addition to the diagnosis, included the fact that only one joint was involved, the synovitis in the affected joint was of recent onset, and the synovial fluid lymphocytes from which the T cells were cloned responded strongly to soluble antigens. Because of the association with the strong response to soluble antigens, synovial fluid T lymphocytes from another patient with rheumatoid arthritis were cloned in response to a crude mycobacterial antigenic mixture. Three of the seven clones examined were identical by Southern blot analysis. These observations suggest that the presence of oligoclonality is limited in patients with inflammatory arthritis. The relationship of a specific antigen-driven response within the joint to the detection of oligoclonal T cells within that joint remains to be determined.

Fine-structure mapping of cis-acting control sites in the lysC operon of Bacillus subtilis

Mutations at the aecA locus of Bacillus subtilis lead to derepression of the lysC operon, which encodes aspartokinase II, and analysis of three independent aecA mutations has shown them to be nucleotide substitutions in the lysC leader region (Y. Lu, N.Y. Chen and H. Paulus (1991) J. Gen. Microbiol. 137, 1135-1141). DNA sequence analysis of the lysC control region of nine other mutants with derepressed levels of aspartokinase II revealed each of the mutations to be associated with changes in one or a few nucleotide residues. The nucleotide substitutions were clustered at two sites in the lysC leader: in a region of imperfect dyad symmetry about 40 base pairs from the transcription start site, and in the open reading frame for a putative leader peptide, which starts about 40 residues further downstream. The effect of nucleotide substitutions at the two sites differed in that those at the upstream site gave twice the degree of derepression. A mutant with a small deletion in the leader peptide coding region potentially affecting RNA secondary structure also had a higher level of lysC derepression. These results suggest that the lysC leader region contains at least two cis-acting control sites that play important and perhaps independent roles in the repression of the lysC operon by lysine.

Some biological properties of a rhabdovirus isolated from penaeid shrimps

Some of the relevant biological properties of a rhabdovirus isolated from penaeid shrimps (RPS) were examined. The virus replicated in an established fish cell line, epithelioma papulosum cyprini (EPC) which allowed for the development of a quantitative plaque assay protocol. Virus replication was not inhibited by the DNA antagonist, 5-bromo-2'-deoxyuridine (20 micrograms/ml). Virus infectivity was sensitive to 20% ethyl ether, low pH, and to 37 degrees C. The virus showed marked lability to repeated freezing and thawing and storage at -10 degrees C, but was stable at -70 degrees C for several weeks. The virus particle to infectious unit ratio in EPC was found to be 30.

[Stability of shuang huanglian aerosol]

The contents of chlorogenic acid and baicalin in shuang huanglian aerosol were determined by HPLC. The process of chemical kinetics of the aerosol was studied by constant temperature acceleration tests, and the stability of the drug predicted. The results appeared close to those from the stored sample method. pH changes during degradation of the drug were also observed.

Hyperpolarizing interplexiform cell of the dace retina identified physiologically and morphologically

One type of interplexiform cell (IPC) in the dace retina was discriminated physiologically from other cell classes and identified morphologically with HRP staining. This type responded with slow hyperpolarizing potentials to white diffuse light, and in addition a slow hyperpolarization (after potential) was observed after the cessation of light with relatively high intensities. The latency of the ON phase of the response was always longer than that of the second-order neurons and the amacrine cells. Morphologically, this type of IPC was similar in appearance with the dopaminergic IPC. The conventional synaptic specialization between this type of IPC and horizontal cells was observed, and the IPC was presynaptic.

Organization and environmental regulation of the Pseudomonas syringae pv. syringae 61 hrp cluster

The ability of Pseudomonas syringae pv. syringae 61 to elicit the hypersensitive response in nonhost plant species has been linked to a cluster of hrp/hrm genes whose expression appears to be environmentally regulated. To understand the genetic organization of this hrp/hrm gene cluster and its expression during the interaction with nonhost plant species better, we constructed a set of chromosomal hrp-uidA fusions in P. syringae pv. syringae 61 by Tn5-gusA1 mutagenesis of the cloned hrp/hrm gene cluster and transferred them into the genome by marker exchange mutagenesis. Complementation analysis employing plasmid-borne Tn5-gusA1 insertions and previously characterized chromosomal TnphoA mutations defined at least eight apparent transcriptional units within the hrp/hrm cluster, several of which were multicistronic. The expression of hrp-uidA fusions in seven of these apparent hrp transcriptional units increased following inoculation into tobacco leaves. Enhanced expression from a representative fusion was detected 1 h after inoculation of tobacco leaves. The induction observed in planta was similar to the levels detected following culture of the bacteria in minimal-salts medium: irrespective of the carbon source. Complex amino acid sources, such as peptone, repressed the expression of P. syringae pv. syringae 61 hrp genes at levels exceeding 0.028%. The results indicate that enhanced expression of hrp genes occurs early in the interaction with nonhost plant species in an apparent response to altered nutritional conditions.

A heparin-binding growth factor secreted from breast cancer cells homologous to a developmentally regulated cytokine

We report purification of an 18-kDa heparin-binding growth factor secreted from human cancer cells which is homologous to a developmentally regulated, neurotrophic factor, heparin-binding growth-associated molecule/pleiotrophin (HB-GAM/PTN; Merenmies, J., and Rauvala, H. (1990) J. Biol. Chem. 265, 16721-16724; Li, Y. S., Milner, P. G., Chauhan, A. K., Watson, M. A., Hoffman, R. M., Kodner, C. M., Milbrandt, J., and Deuel, T. F. (1990) Science 250, 1690-1694). We have purified the protein from tissue culture supernatants of human breast cancer cells (MDA-MB 231) and have used soft agar cloning of an epithelial cell line (SW-13) to detect its growth stimulating activity. A 32,000-fold purification was achieved by isoelectric focusing, heparin affinity chromatography, and reversed phase high pressure liquid chromatography. The molecular mass of the protein was confirmed by gel filtration chromatography in the presence of detergent and bioassay of the fractions. The N-terminal sequence was homologous to HB-GAM/PTN, and polymerase chain reaction amplification and DNA sequencing confirmed that the respective transcript was present in the cancer cells. We conclude that HB-GAM/PTN can function as a tumor growth factor in addition to its role during neuronal development.

[Discussion on criteria for appraising the endanger threatening rare medicinal plants]

This paper deals with the criteria for appraising the endanger threatening rare medicinal plants. A preliminary evaluating method is presented.

[Chemical constituents of Rhodiola kirilowii (Reg.) Reg]

Three compounds were isolated from the water-soluble part of alcohol extracts of rhizomes of Rhodiola kirilowii. Two of them were identified as salidroside and tyrosol, respectively by chemical and spectral analysis. beta-sitosterol was obtained from the petroleum extracts of the plant.

[Quantitative direct gas-liquid chromatography for rapid diagnosis of anaerobic infections]

Quantitative direct gas-liquid chromatography (GLC) was performed on 74 specimens of surgical infections and relevant findings were compared with cultural results. In the present study, significant amounts of multiple volatile fatty acids (VFA) and/or succinate were found as markers of anaerobic infections. At least one of the VFA (propionic, isobutyric, butyric, isovaleric or valeric acid) greater than or equal to 0.1 mumol/ml and/or succinate greater than or equal to 0.3 mumol/ml was strong evidence for anaerobic infections. More than 3.5 mumol/ml of butyric acid was interpreted as indication of the presence of Fusobacterium spp. Succinate greater than or equal to 0.3 mumol/ml was associated with the presence of Bacteroides fragilis.

[Composition of essential oil from inflorescences of Rhaponticum uniflorum (L.) DC]

The essential oil was extracted from the inflorescences of Rhaponticum uniflorum which are used as a Mongolian drug. 30 compounds in the oil were identified by GC-MS and their percentages were determined by GC.

Proopiomelanocortin gene promoter elements required for constitutive and glucocorticoid-repressed transcription

The POMC gene is expressed predominantly in the anterior pituitary. The high level of POMC transcription in this tissue is modulated by peptide hormones and repressed by glucocorticoids. In this present study we have investigated promoter elements required for the high basal transcription and glucocorticoid repression using transient transfection and in vitro transcription assays. We first determined that the region between -77 to -51 of the promoter, which has previously been shown to harbor a glucocorticoid receptor-binding site, is required for high basal expression both in vivo and in vitro. This promoter domain is also required for glucocorticoid repression of transcription in vivo. Two site-directed mutants within this area both decreased basal transcription, but were fully repressed by glucocorticoids, implying that the -77 to -51 region is a complex regulatory region harboring separable basal and glucocorticoid-repressible elements. Electrophoretic mobility shift and exonuclease III footprinting analysis revealed the existence of two factors that bind in this region. We also examined the effect of broad promoter deletions on basal expression and glucocorticoid repression. These experiments revealed that the region between -480 and -320 is also required for glucocorticoid repression. Taken together, the data suggest a model in which high basal transcription is generated by direct interaction of factors binding between -480 to -320 and -77 to -51. Glucocorticoid repression could occur by direct receptor disruption of these interactions.

Experimental and theoretical studies on monitored signals from semiconductor diodes undergoing antireflection coatings

Rate equations have been used to analyze the variations of the outputs from the facets of the diodes being coated during the antireflection-coating process. Good agreement between the experimental recordings and theoretical predictions has been achieved. As a result, an auxiliary criterion for on-time assessment of the antireflection coating has been established.

Automated severity classification of AIDS hospitalizations

To validate an automated AIDS severity-of-illness prognostic algorithm, 2,113 discharge summaries of HIV-infected patients were merged with the Problem-Oriented Medical Synopsis (POMS) and an HIV risk registry. The combination of a medically derived classification and staging algorithm with multivariate statistical techniques was used for automated severity-of-illness disease staging and prognostic assignment. The model correctly predicted the outcomes of 82% of all cases (death, survivorship) at discharge, and 66% of deaths.

Retinal [125I]iodomelatonin binding sites in the tree shrew (Tupaiidae)

The characteristics of melatonin-binding sites labelled by [125I]iodomelatonin in membrane preparations from the tree shrew retina were determined. Specific binding of [125I]iodomelatonin to the membrane preparations of tree shrew retina was rapid, stable, saturable, and reversible. Among the indoles tested only 6-chloromelatonin, melatonin and N-acetylserotonin had significant affinities to the [125I]iodomelatonin binding site. Scatchard analysis of the membrane preparations revealed a dissociation constant (Kd) of 51.0 +/- 16 pM and a total number of binding sites (Bmax) of 1.97 +/- 0.6 fmol/mg protein.

Binding characteristics and regional distribution of [125I]iodomelatonin binding sites in the brain of the human fetus

The binding and pharmacological characteristics of [125I]iodomelatonin binding sites in human fetal brain membrane preparations were determined. Membrane preparations of the whole brain revealed a equilibrium binding constant (Kd) of 17.5 pmol/l with a total number of binding sites (Bmax) at 0.8 fmol/mg protein. Among the various brain regions studied, [125I]iodomelatonin binding was highest in the hypothalamus, and lowest in the mid-brain, pons-medulla, and cerebral cortex. The Kd of the hypothalamus was calculated to be 26.1 pmol/l and the Bmax 5.4 fmol/mg protein. Only 6-chloromelatonin, melatonin and N-acetylserotonin had significant inhibition in the binding. Our results suggest that melatonin receptors are present in the human brain and that melatonin may exert a central action.

[A study of textile noise influence on maternal function and embryo-growth]

Ninety hundred seventy-eight female textile workers exposed to noise (greater than or equal to 85 dB (A)) were recruited as the subjects of observation group, and 402 nonexposed female workers were chosen as the controls (less than 75 dB (A)). According to noise level, the observation group was subdivided into three groups: group 1, 100-104 dB (A), 416 workers; group 2, 95-99 dB, (A), 310 workers; group 3, 85-94 dB (A), 252 workers. Non-conditional logistic regression model was used to exclude the effect of mixed factors, such as age and working life. The result showed that noise-exposure could have some adverse effect on reproductive function of women and embryo growth. The workers exposed to noise had significantly increased incidence rates for irregular menstrual cycle, dysmenorrhea, lumbago, hypertension in pregnancy, threatened abortion, spontaneous abortion, premature labour, dystocia and low birth weight of newborns. When the noise intensity heightened, the sorts of abnormal function of reproduction increased and the risk of incidence raised too. These demonstrated a dose-response relationship between the noise intensity and incidence rate. The noise-working life had significant effects on the incidence of hypertension in pregnancy and prematurity. Although the age had some influence, it was not statistically significant. In terms of the maternal function and embryo growth, the factors in order of risk are: noise intensity greater than working life greater than age.

[Correlation between neonatal Apgar scores and the results of maternal and umbilical cord blood gas analysis]

The correlation between the Apgar scores of 162 neonatal 1 minute after birth and the result of maternal arterial and umbilical cord blood gas analysis was studied. The results were as follows: (1) With decreasing neonatal Apgar score, the value of the pH, PO2, HCO3, TCO2 and actual base excess (ABE) of the maternal arterial and umbilical cord blood also decreased markedly, while the PCO2, except that of the maternal arterial blood, increased obviously, and mixed acid base imbalance and hypoxemia also significantly increased (P less than 0.01). (2) Of the neonates with umbilical arterial blood pH less than or equal to 7.2, the proportion of neonates with Apgar score less than or equal to 3 amounted to 100%; that with on Apgar score of 4-7, was 77.7%; And that with on Apgar score of 8-10, was 56.31%. The difference was highly significant statistically (P less than 0.01).

[Quantitative analysis of calcium bilirubin in calculus bovis by infrared spectrometry]

This paper reports the method of quantitative analysis of calcium bilirubin in calculus bovis by infrared spectrometry. This method is simple and quick, requiring no separation and only small amount of sample, not destroying the sample and having few interferences.

Identification of aecA mutations in Bacillus subtilis as nucleotide substitutions in the untranslated leader region of the aspartokinase II operon

Recent genetic mapping of the aspartokinase II (lysC) operon of Bacillus subtilis [M. Petricek. L. Rutberg & L. Hederstedt (1989) FEMS Microbiology Letters 61, 85-88; N.Y. Chen. J. J. Zhang & H. Paulus (1989) Journal of General Microbiology 135, 2931-2940] has shown its chromosomal location to be close to the aecA locus, the mutation of which leads to highly increased levels of aspartokinase II. In order to examine the relationship between lysC and aecA, we have cloned the control regions of the lysC operon from several independent aecA mutants and determined their nucleotide sequences. The nucleotide sequences of the aecA mutants differed from the wild-type sequence by the substitution of one or two nucleotides at two widely separated sites in the transcribed leader region of the lysC operon. To confirm that the observed nucleotide changes are indeed responsible for the AecA phenotype and not simply the reflection of sequence polymorphisms in different B. subtilis strains, we introduced the same nucleotide substitutions as those observed in the aecA strains into the leader region of the wild-type lysC operon by oligonucleotide-directed mutagenesis. The expression of the mutagenized genes was analysed after transcriptional or translational fusion to lacZ in a single-copy integration vector. The levels of beta-galactosidase were greatly elevated by the nucleotide substitutions, with similar increases observed in transcriptional and translational fusions. The high level of expression of beta-galactosidase in the lysC'-lac'Z strains with nucleotide substitutions corresponding to the aecA mutations was resistant to repression by L-lysine but was completely abolished by the inactivation of the lysC promoter.(ABSTRACT TRUNCATED AT 250 WORDS)

[125I]iodomelatonin binding sites in spleens of birds and mammals

The specific binding of [125I]iodomelatonin to duck spleen membrane preparations was studied in detail. These binding sites were stable, saturable, reversible and of high affinity. Scatchard analysis of the binding revealed a equilibrium binding constant (Kd) of 73.1 +/- 5.4 pM and a total number of binding sites (Bmax) of 3.64 +/- 1.38 fmol/mg protein. Studies on the relative binding capacities of [125I]iodomelatonin to the spleen in different species showed the following order: duck greater than chicken greater than guinea pig greater than pigeon greater than mouse. No binding site was detected in the rat spleen. The presence of [125I]iodomelatonin binding sites in the spleen of birds and mammals suggested a direct action of pineal melatonin on the immune system.

Regulation of testicular P-450 cholesterol side-chain cleavage and P-450 C17-20 lyase/C17 hydroxylase enzymes in the neonatal and adult rat

Adult Leydig cells respond to LH or hCG with an initial stimulation of testosterone secretion followed by LH receptor down-regulation and blockade of androgen biosynthesis. In contrast, fetal Leydig cells respond with increased LH receptor number and enhanced steroidogenesis. In this study, the molecular mechanisms of high-dose hCG treatment on steroidogenesis in adult and neonatal testes (containing predominantly the fetal generation of Leydig cells) were examined using two recombinant DNA clones specific for enzymes of the rat steroidogenic pathway (P-450 cholesterol side-chain cleavage enzyme, P-450scc and P-450 17 alpha-hydroxylase/C17-20 lyase, P-450c17). We treated adult (60 days of age) and neonatal (2 days of age) rats with a single high dose of hCG (600 IU/kg), sc. The high dose of hCG caused neonatal testicular P450scc and P450c17 mRNA levels to increase, and stimulated adult testicular P450scc mRNA levels, but caused a decrease in adult P450c17 mRNA levels. These studies suggest that high doses of hCG regulate testosterone production differently in adult and fetal Leydig cells at a pretranslational level of the P450c17 enzyme, while mRNA for P450scc is stimulated in both the adult and fetal Leydig cell.

Regulation of glycan processing by Golgi enzymes from red kidney bean (Phaseolus vulgaris) seedlings

The effect of a protein matrix on the processing of glycoprotein glycans by Golgi enzymes from plant seedlings has been determined with an artificial glycoprotein system, comparing the processing rates of glycan-(biotinyl)Asn (or glycan-(biotinamidohexanoyl)Asn) substrates either free or bound to avidin. An analysis of the pooled glycoproteins from the seedlings suggested that the most common glycan structure is a complex one (GlcNAc-Man3GlycNAc2-protein), and consistent with this processing end-product, mannosidases I and II and GlcNAc transferases I and II were all found to be present in the seedling Golgi membrane preparations. The effect of the avidin matrix either in a proximal (biotinyl substrates) or distal (N-(biotinamido)hexonoyl substrates) association with the appropriate glycan substrate for these four enzymes was assessed from the direct comparison of the apparent first-order rate constants for the free and avidin-bound substrate-product conversions. All four plant enzymes were inhibited by the association of the glycan substrates with avidin, but the inhibition was much less pronounced than that observed with the corresponding enzymes from rat liver and hen oviduct. The rate effect shows a progression from 3- to 10-fold rate decreases in the proximal complexes and 2- to 3-fold in the distal complexes in going from the first (mannosidase I) to the fourth (GlcNAc transferase II) enzyme; with the mammalian and avian enzymes the largest effects were for the first ones and much larger absolute rate effects were observed. The results suggest that the nature of the processing enzymes in terms of this response to the avidin glycan substrates may differ in different organisms.

Expression of chimeric human transferrin genes in vitro

Transferrin (TF), a major plasma protein, binds and transports ferric iron. Evidence exists for unique roles for TF in brain in oligodendrocyte differentiation, myelination and neuronal development. In this study, 5' flanking regions of the TF gene important in regulating gene expression were identified by transfected cell studies and a comparison of 5' flanking sequences of the human TF and TF receptor genes. Human glioma cell lines HTB-16 and HTB-17 were shown to synthesize TF identical in size and immunological reaction to TF synthesized by liver. The expression of a series of human chimeric TF genes in glioma cells was compared with hepatoma and HeLa cells. A difference in transient expression was observed in hepatoma and glioma cells transfected with TF chimeric genes containing 3.9 kb of the 5' region; hepatoma cells demonstrated significantly more expression than did glioma cells, suggesting that a DNA region present in the 3.9-kb construct is important either in liver-specific expression or in repression of brain expression, or in both. Smaller constructs containing less than or equal to 0.622 kb of the 5' regulatory region of the TF gene failed to demonstrate cell-specific expression; they were expressed in HeLa cells, a line that does not synthesize TF. High levels of expression of 0.15-kb TF constructs were also observed in hepatoma and glioma cell lines, but not in transgenic mice. Possible explanations of differences observed in expression of shorter TF constructs in vitro and in vivo are discussed.

Interactions between N-methyl-D-aspartate and CGS 19755 administered intramuscularly and intracerebroventricularly in pigeons

Behavioral effects of N-methyl-D-aspartate (NMDA) and the competitive NMDA antagonist cis-4-phosphonomethyl-2-piperidine-carboxylic acid (CGS 19755) were studied in pigeons. NMDA decreased responding under a fixed-ratio schedule of food presentation and was 8000 times more potent administered intracerebroventricularly (i.c.v.) as compared to intramuscularly (i.m.). CGS 19755 was 870 times more potent in producing catalepsy when administered i.c.v.; however, the duration of catalepsy was similar by the two routes of administration. Administered i.m. CGS 19755 decreased response rates only at doses that also produced catalepsy; administered i.c.v. some doses of CGS 19755 decreased responding without producing other behavioral effects. Rate-decreasing effects of i.m. NMDA were attenuated by i.m. CGS 19755; however, when CGS 19755 was administered i.c.v., there was little or no antagonism of NMDA. Rate-decreasing effects of i.c.v. NMDA were not attenuated by i.m. or i.c.v. CGS 19755 up to doses that produced catalepsy or eliminated responding. The large difference in potency between i.m. and i.c.v. administration for NMDA and for CGS 19755, as well as the slower onset of catalepsy when CGS 19755 was administered i.m., suggests these compounds do not readily cross the blood-brain barrier when administered parenterally. The inability of CGS 19755 to attenuate the rate-decreasing effects of NMDA when CGS 19755 or NMDA was administered i.c.v. suggests NMDA might decrease responding by different mechanisms when administered i.m. or i.c.v. in pigeons. Together these results indicate antagonism of NMDA in this study, and perhaps in other studies, when both NMDA and CGS 19755 were administered parenterally, might result from a peripherally mediated interaction. Moreover, this agonist-antagonist interaction is not a simple, competitive antagonism.

[Inhibition of growth and metastases of lung carcinoma in C57BL/6 mice by Corynebacterium parvum and its antitumor mechanism]

Cocrynebacterium parvum (CP) was injected around the tumor and tumor cells were inoculated subcutaneously with activated peritoneal macrophages. The effects on the growth and metastases of Lewis lung carcinoma in C57BL/6 mice were observed. Experimental results indicated that CP had significant inhibitory effect on the tumor growth and lung metastases. The cytotoxic effects of activated peritoneal macrophages in mice on target tumor cells (L5178Y) in vitro were studied with the technique of 3H-TdR assay. The proliferation of tumor cells was markedly inhibited by the activated peritoneal macrophages of CP. Experiments showed that the antitumor mechanism of CP was the mediation via activated cytotoxic macrophages. These results indicated that CP is an effective immunostimulant. These findings will provide a scientific basis for the clinical treatment of the primary and metastatic lung carcinoma.

CT-guided transcutaneous fine-needle aspiration biopsy. A report of 350 cases

CT-guided transcutaneous fine-needle aspiration biopsies were done in 350 patients. They involved the abdomen in 226 patients (liver 75, pancreatic and abdominal masses 51, kidney 96, adrenal gland 3, spleen 1), thorax 90, musculoskeletal system 32, and brain 2. The accuracy varied with different locations. The accuracy of liver biopsy was 94%, kidney 95.8%, pancreatic and abdominal masses 88.2%, thorax 90%, and musculoskeletal system 96.5%. The occurrence rate of complications was 2.3%. Pneumothorax occurred in 7 patients having thorax biopsy, and gastric perforation in one patient after abdominal biopsy. The proper selection of fine needles, the method and technique, the influential elements of the accuracy, and the application of CT-guided aspiration biopsy were detailed in this paper.

Tumor necrosis factor and interleukin-1 stimulate testosterone secretion in adult male rat Leydig cells in vitro

The actions of two cytokines, tumor necrosis factor (TNF) and interleukin-1 (IL-1), on testosterone production by dispersed adult testis cells and purified Leydig cells in culture were studied. In one set of experiments, testis cells from adult (90-day-old) rats were enzymatically dispersed. In another set of experiments, the dispersed testis cells were placed on a Percoll density gradient and were centrifuged to yield purified (greater than 85%) Leydig cells. Both whole testis cells and purified Leydig cells were cultured in the presence of varying doses of TNF or IL-1 with or without maximally stimulating doses of human chorionic gonadotropin (hCG). Both TNF and IL-1 stimulated basal secretion of testosterone in whole testis cells, as well as purified Leydig cells. Additionally, both TNF and IL-1 augmented maximally hCG stimulated testosterone secretion. Both cytokines stimulated testosterone secretion by dispersed testis cells as early as 4 hours, and the effect continued for up to 72 hours. The cytokines slightly, but significantly, stimulated testosterone production in purified Leydig cells after 24 hours, and continued for up to 72 hours. We have concluded from this data that TNF and IL-1 stimulate the testosterone secretion by adult rat Leydig cells. While this effect might be mediated through the action of the cytokines on testicular macrophages, there might also be a direct effect on the Leydig cell since augmentation of secretion occurred in purified Leydig cells, as well as whole testis cells. Therefore, TNF and IL-1 may serve as local regulators of Leydig cell function.

Growth of the penaeid shrimp virus infectious hypodermal and hematopoietic necrosis virus in a fish cell line

An established fish cell line, epithelioma papillosum cyprini (EPC), originating from the carp (Cyprinus carpio) was found to be susceptible to the penaeid shrimp virus, infectious hypodermal and hematopoietic necrosis virus (IHHNV). This economically important pathogen of penaeid shrimp raised in mariculture has been previously limited to growth only in young post-larval shrimps. This is, to our knowledge, the first reported successful growth of the penaeid virus in a fish cell line; it promises to provide a sensitive and convenient cell culture system for the primary isolation and detection of IHHNV which will aid immensely the production of IHHNV-free penaeid shrimp stocks for mariculture. Of added significance is the replication of a crustacean virus in a fish cell line which has never before been reported. The use of this sensitive cell line will also greatly facilitate the characterization of the IHHN virus and other crustacean viruses.

Evaluation of N-4-(hydroxycarbophenyl) retinamide as a cancer prevention agent and as a cancer chemotherapeutic agent

In this review, a retinoid analogue (N-4-hydroxycarbophenyl) retinamide (R11) has been evaluated for its pharmacological and clinical properties. R11 has been studied both as a cancer prevention agent, as well as, a cancer chemotherapeutic agent. R11 alone and in combination with other agents can be used for the treatment of cervical dysplasia or leukemia. This review will examine novel strategies and mechanisms of action for retinoids in the treatment and prevention of cancer.