p53 point mutation and survival in colorectal cancer patients

We have examined the relationship between point mutation of the p53 tumor suppressor gene and survival in colorectal cancer patients. We found that patients with tumors harboring mutated p53 genes showed a significantly poorer prognosis than did those patients with genes without point mutations, and, moreover, patient response to postoperative therapies depended significantly on mutation status in both adjuvant and palliative treatment cohorts. However, not all point mutations were the same functionally; point mutations within the conserved domains of the p53 tumor suppressor gene were inherently more aggressive than tumors with point mutations outside of these domains, and mutations of codon 175 were particularly aggressive. These results suggest that knowledge of a patient's p53 status, both with respect to the presence of point mutations and to the specific nature of the lesion, may be required to accurately predict both the course of the disease and the response of the disease to postoperative therapeutic interventions, especially those therapies based on the induction of apoptosis in the neoplastic cell.

Production of transforming growth factor-beta by cultured rat mesangial cells

The purpose of this study was to examine whether transforming growth factor-beta (TGF beta) acts as an autocrine cytokine in cultured mesangial cells. Measangial cell conditioned media (CM) were prepared and tested for their effect on mesangial cell proliferation. CM showed a concentration dependent inhibition on mesangial cell proliferation and the activity was enhanced by treating conditioned media with acid. Gel filtration analysis showed peak inhibitory activity to reside in fractions with an estimated molecular weight range of 16-30 KD. The activity was partially blocked by anti-TGF beta antibody, but not nonimmune control IgG. The presence of TGF beta was confirmed using the mink lung epithelial cell assay. Furthermore, the addition of anti-TGF beta antibody directly into culture media significantly enhanced mesangial cell proliferation. These results demonstrate that measangial cell produce both active and latent forms of TGF beta, which functions as an autocrine growth inhibitor for mesangial cells.

Analysis of high-mass biomolecules using electrostatic fields and matrix-assisted laser desorption/ionization in a Fourier transform mass spectrometer

A new decelerating technique that places dc potentials on the orthogonal excitation and receiver plates as well as the rear trapping plate (conductance limit) of the source cell of a dual cubic cell has been applied to the standard matrix-assisted laser desorption/ionization Fourier transform mass spectrometry technique. When this five-plate trapping method is applied, high-mass ions with large translational kinetic energies can be trapped efficiently and detected. Using this approach, low-resolution spectra of carbonic anhydrase (MW = 29,000), egg albumin (MW = 45,000), and bovine albumin (MW = 66,000) have been obtained. Because the new decelerating method requires no modification to the existing cell, it is also possible to obtain high-resolution spectra for compounds with masses of ca. 14,000 Da and lower. Utilizing the five-plate trapping method, a bovine insulin spectrum with a resolving power of 20,000 was obtained. It is not yet possible to obtain higher resolution for the higher mass proteins. The reasons for this difficulty are currently being investigated.

The potential role of fibroblasts in periprosthetic osteolysis: fibroblast response to titanium particles

Periprosthetic osteolysis with or without aseptic loosening is a major clinical problem in total hip arthroplasty. While the macrophage response to prosthetic wear debris and its role in periprosthetic osteolysis has been extensively studied, information regarding other cell types (fibroblasts, osteoblasts) is limited. This study explored the response of fibroblasts to particulate wear debris. Fibroblasts isolated from interfacial membranes of patients with failed total hip replacements and normal synovial tissue, when challenged with small-sized ( < 3 microns) titanium (Ti) particles, responded with significantly enhanced expressions of collagenase, stromelysin and, to a much lesser extent, their tissue inhibitor of metalloproteinases (TIMP). These "regulated" expressions at both mRNA and protein levels were correlated with the size and composition of particles. De novo protein synthesis was required for the regulation of these mRNAs. A similar effect could be induced by the treatment of the cells with particle-free conditioned medium from Ti particle-stimulated fibroblasts. Furthermore, this conditioned medium significantly suppressed the mRNA levels of procollagen alpha 1 (I) and alpha 1 (III) in osteoblast-like MG-63 cells. It is concluded that fibroblasts stimulated with certain particle debris may play an important role in periprosthetic osteolysis by releasing bone-resorbing metalloproteinases and mediator(s) which resulted in suppressed collagen synthesis in osteoblasts.

1H, 13C and 15N chemical shift referencing in biomolecular NMR

A considerable degree of variability exists in the way that 1H, 13C and 15N chemical shifts are reported and referenced for biomolecules. In this article we explore some of the reasons for this situation and propose guidelines for future chemical shift referencing and for conversion from many common 1H, 13C and 15N chemical shift standards, now used in biomolecular NMR, to those proposed here.

Increases in CSF levels of interleukin-2 in schizophrenia: effects of recurrence of psychosis and medication status

OBJECTIVE

Interleukin-2, traditionally viewed as solely involved in immunological events, has recently been shown to exert profound effects on the development and regulation of the central nervous system. This study examined the relationships between interleukin-2 in the CSF and plasma of schizophrenic patients and clinical measures, including relapse and medication status. Plasma and CSF interleukin-1 alpha levels were also measured to ascertain the specificity of changes in cytokine levels.

METHODS

Seventy-nine physically healthy male patients with schizophrenia (DSM-III-R) received diagnostic evaluation and behavioral ratings. Haloperidol treatment was withdrawn for up to 6 weeks and patients were evaluated for symptom recurrence. CSF and plasma were obtained by established procedures before haloperidol withdrawal (N = 79) and after (N = 64).

RESULTS

CSF levels of interleukin-1 alpha decreased significantly after haloperidol withdrawal but showed no relation to clinical status. In contrast, levels of CSF interleukin-2 were associated with recurrence of psychotic symptoms. Relapse-prone patients, examined both while medicated and after drug withdrawal, had significantly higher levels of CSF interleukin-2 than patients who did not relapse. CSF interleukin-2 level during haloperidol treatment was a significant predictor of worsening in psychosis.

CONCLUSIONS

Levels of interleukin-2, a molecule that plays both neurodevelopmental and neuroregulatory roles, may have a role in relapse in schizophrenia. Levels of CSF interleukin-2 appear to be affected by relapse mechanisms, while peripheral blood levels are not. These changes are specific to interleukin-2, since levels of interleukin-1 alpha were affected by medication withdrawal but not by change in clinical state.

[Expression of adhesion molecules on lymphocyte in patients with systemic lupus erythematosus]

Peripheral blood lymphocyte phenotype (CD3, CD4, CD8, CD20, CD45RA and CD45RO) and adhesion molecule phenotype (CD11a/LFA-1 alpha, CD18/LFA-1 beta and CD54/ICAM-1) were investigated in 35 patients with systemic lupus erythematosus (SLE) by using flow cytometric analysis and dual immunofluorescence staining method. Results demonstrated increase in CD8+ cell and decrease in CD4+ cell, CD4+/CD8+, and CD4+/CD45RA+ cell, as well as decrease in expression of CD11a and CD18 on CD4+ cell surface, Expression of CD11a and CD18 on CD8+ cell, and CD54 on CD20+ cell increased, Moreover, increase in CD18 on CD8+ cell correlated inversely with decrease in CD4+ CD45RA+ cell (P < 0.05) and positively with increase in CD54 on CD20+ cell (P < 0.01). These data suggest that adhesion molecule LFA-1 and ICAM-1 may play an important role in the pathogenesis of SLE.

Measurement of acetabular version on the axiolateral radiograph

There are 3 definitions of acetabular version: true (anatomic) version, planar (radiographic) version, and operative version. Although planar version can be measured on standard radiographs, the measurement may be inaccurate when applied to metal-backed acetabular components. However, another version angle is depicted clearly on an angled, cross-table lateral radiograph of the hip--the axiolateral view, and this angle readily distinguishes anteversion from retroversion. If the angle of the xray beam is known or is standardized, version measured on the axiolateral view can be converted to the other version angles. Nomograms for these conversions are presented. In most cases, acetabular version measured on the axiolateral radiograph closely approximates planar version.

[Simplified enzyme-linked immunoadsorbent assays for myelin basic protein and antibodies to myelin basic protein]

Synchronous quantitative determination using simplified enzyme-linked immuno adsorbent assay has been developed for myelin basic protein (MBP) and antibodies to myelin basic protein (Anti-MBP). Antisera were prepared by immunizing rabbits with purified MBP from human white matter. Antibodies to MBP was conjugated with horseradish peroxidase (HRP) by using modified periodate oxidation method. Minimum detection amounts of MBP and Anti-MBP are 0.25 ng/ml and 0.20 ng/ml respectively. The activities of Anti-MBP-HRP conjugates are stable (stored at -30 degrees C) for at least 2 years. The detection procedure can be accomplished within 24 hours.

Molecular cloning of a bovine ornithine decarboxylase cDNA and its use in the detection of restriction fragment length polymorphisms in Holsteins

A cDNA coding for ornithine decarboxylase (ODC) was isolated from a bovine liver cDNA library. The clone (1758 base pairs) consisted of 5'- and 3'-untranslated regions of 185 and 187 nucleotides, respectively, and an open reading frame of 1383 nucleotides encoding an ODC protein (M(r) 51,342 daltons) of 461 amino acids. Comparison of the nucleotide and the predicted amino acid of the cDNA with other mammalian ODCs showed a very high degree of homology both at the DNA and protein levels. The bovine ODC mRNA was identified by northern blot to be a single species with a molecular size of 2.35 kilobase pairs. Primer extension analysis indicated that the 5'-untranslated region of the bovine ODC mRNA was 312 nucleotides long. Southern blot analysis of bovine genomic DNA revealed restriction fragment length polymorphisms when cleaved with restriction enzymes PstI, MspI, TaqI, and Bg/I.

The generalized Gabor transform

The generalized Gabor transform (for image representation) is discussed. For a given function f(t), tinR, the generalized Gabor transform finds a set of coefficients a(mr) such that f(t)=Sigma(m=-infinity)(infinity)Sigma (r=-infinity)(infinity)alpha(mr )g(t-mT)exp(i2pirt/T'). The original Gabor transform proposed by D. Gabor (1946) is the special case of T=T'. The computation of the generalized Gabor transform with biorthogonal functions is discussed. The optimal biorthogonal functions are discussed. A relation between a window function and its optimal biorthogonal function is presented based on the Zak (1967) transform when T/T' is rational. The finite discrete generalized Gabor transform is also derived. Methods of computation for the biorthogonal function are discussed. The relation between a window function and its optimal biorthogonal function derived for the continuous variable generalized Gabor transform can be extended to the finite discrete case. Efficient algorithms for the optimal biorthogonal function and generalized Gabor transform for the finite discrete case are proposed.

Stabilization of a type VI turn in a family of linear peptides in water solution

The sources of the stability of a type VI turn formed with high population in the cis isomeric form of an unblocked six residue peptide, Ser1-Tyr2-Pro3-Tyr4-Asp5-Val6 (SYPYDV), were investigated by making extensive amino acid substitutions at residues 2, 4 and 5. Several NMR parameters indicate the presence of the turn, including significant upfield shifts of the proton resonances of the cis proline, a small 3JHN alpha coupling constant for residue 2, a cross-turn d alpha N(i,i+2) from residue 2 to residue 4 and in increased mole fraction of the cis form in the conformational ensemble. By these criteria, a number of peptides were found to contain significant populations of type VI turn conformers in the cis form of the peptide. The NMR parameters are highly dependent on the sequence of the peptide, and are strongly correlated with each other and with the population of type VI turn. The greatest populations of turn conformations were observed for peptides of the general form AA-Ar-Pro-Ar-Hp, where AA represents any amino acid, Ar an aromatic residue and Hp a small hydrophilic residue. There is no evidence in the form of lowered amide proton temperature coefficients for direct hydrogen bonding as a primary source of turn stability. Instead, the major stabilizing factor, indicated by the strong dependence of the turn population on the presence of aromatic (not hydrophobic) residues at positions 2 and 4, is the stacking of the aromatic and proline rings. A measurable preference for deprotonated aspartate at position 5, which is not part of the turn itself, and the destabilization of the turn at high and low pH, indicate that electrostatic interactions between the unblocked N terminus and the aspartate carboxyl group also act to stabilize the turn conformation when the Ar-Pro-Ar sequence is present. Implications for stabilization of local elements of secondary structure during the earliest events in protein folding are discussed.

Three-dimensional structure of a type VI turn in a linear peptide in water solution. Evidence for stacking of aromatic rings as a major stabilizing factor

Structures have been calculated for the folded conformation found at high population in the cis isomeric form of the peptide NH3(+)-Ser-Tyr-Pro-Phe-Asp-Val-COO- (SYPFDV) in aqueous solution, using distance geometry and restrained molecular dynamics. A number of NMR parameters, including NOE distance restraints and phi and chi 1 dihedral angle restraints derived from coupling constants were used in the calculation. The restraints were carefully selected to exclude those that might have a significant contribution from the unfolded states of the peptide, so that the calculated structure represents only the folded form (present at about 70% population) and contains no information on the other members of the conformational ensemble. The calculations give a tight family of structures in the region Tyr2 to Phe4, all containing a type VI turn with an unusual disposition of the aromatic rings of Tyr and Phe, which stack against the proline ring. Both backbone and side-chain conformations are well defined in this region. At the ends of the molecule the polypeptide chain is disordered. The structures are consistent with all of the available NMR information, including upfield chemical shifts observed for the proline ring protons in the cis isomer, and with the independently determined proline ring pucker. There is no evidence for cross-turn hydrogen bonding. According to the calculated structures, the major source of stabilization of the turn conformation appears to be the stacking of the aromatic and proline rings.

Astrocytosis and axonal proliferation in the hippocampus of S100b transgenic mice

S100 beta is a calcium-binding protein that is expressed at high levels in brain primarily by astrocytes. Addition of the disulfide-bonded dimeric form of S100 beta to primary neuronal and glial cultures and established cell lines induces axonal extension and alterations in astrocyte proliferation and phenotype, but evidence that S100 beta exerts the same effects in vivo has not been presented. An 8.9-kb murine S100b genomic clone was used to produce two lines of transgenic mice in which S100 beta RNA is increased in a dose-related manner to 2-fold and 7-fold above normal. These lines show concomitant increased S100 beta protein throughout the brain. Expression in both lines is cell type- and tissue-appropriate, and expression levels are correlated with the transgene copy number, demonstrating that sequences necessary for normal regulation of the gene are included within the cloned segment. In the hippocampus of adult transgenic mice, Western blotting detects elevated levels of glial fibrillary acidic protein and several markers of axonal sprouting, including neurofilament L, phosphorylated epitopes of neurofilament H and M, and beta-tubulin. Immunocytochemistry demonstrates alterations in astrocyte morphology and axonal sprouting, especially in the dentate gyrus. Thus, both astrocytosis and neurite proliferation occur in transgenic mice expressing elevated levels of S100 beta. These transgenic mice provide a useful model for studies of the role of S100 beta in glial-neuronal interactions in normal development and function of the brain and for analyzing the significance of elevated levels of S100 beta in Down syndrome and Alzheimer disease.

Role of transforming growth factor-beta in the growth inhibition of cultured rat mesangial cells in high glucose media

The present study was designed to test the hypothesis that the inhibitory effect of elevated glucose levels on mesangial cell growth might be mediated by transforming growth factor beta (TGF beta). Increased glucose levels inhibited mesangial cell proliferation in a concentration dependent manner. The addition of a rabbit antipocine TGF beta 1 neutralizing antibody significantly enhanced the cell proliferation in both normal (5.5 mM) and high (50 mM) glucose media (12% and 30% respectively), and almost completely blocked the growth inhibition induced by high glucose media. TGF beta assay demonstrated mesangial cells produced more active than latent TGF beta after growth in high glucose media. We conclude that TGF beta functions as an autocrine cytokine in mesangial cells growth and the production of TGF beta is modulated by high glucose concentration. The growth inhibition induced by high glucose levels may be largely mediated by endogenous TGF beta.

A report using a hybrid ICD system: the need for compatibility among implanted defibrillator components

The successful implantation of an ICD system with hardware from three different manufacturers is described. This case exemplifies the need for compatibility of components among different manufacturers. This is most relevant at a time when rapidly changing technology and hardware availability may require a mixing, by informed practitioners, of ICD system components. The parallel to the development of the uniform IS-1 standard for bradycardia devices is made.

Cerebrospinal fluid corticotropin-releasing factor increases following haloperidol withdrawal in chronic schizophrenia

Corticotropin-releasing factor (CRF), an endogenous neuropeptide, has been shown to coordinate endocrine, behavioral and autonomic responses to stress. However, while previous studies of cerebrospinal fluid (CSF) CRF in schizophrenia have not demonstrated significant differences compared to control groups, these studies have not examined the effects of symptom severity or antipsychotic medication. CSF CRF concentrations increased in 18 of 21 male schizophrenic (DSM-III-R) patients after maintenance haloperidol was replaced by placebo (P < 0.0001); there was also a trend for relatively greater increases in relapsers. CRF concentrations were not significantly related to severity of psychosis, depression, anxiety or negative symptoms. During haloperidol treatment, but not after medication withdrawal, worse childhood premorbid adjustment was associated with higher CSF CRF levels. Finally, in contrast to the positive correlation between CSF CRF and norepinephrine concentrations reported in depression, a negative trend was seen in this schizophrenic sample.

Model observers for assessment of image quality

Image quality can be defined objectively in terms of the performance of some "observer" (either a human or a mathematical model) for some task of practical interest. If the end user of the image will be a human, model observers are used to predict the task performance of the human, as measured by psychophysical studies, and hence to serve as the basis for optimization of image quality. In this paper, we consider the task of detection of a weak signal in a noisy image. The mathematical observers considered include the ideal Bayesian, the nonprewhitening matched filter, a model based on linear-discriminant analysis and referred to as the Hotelling observer, and the Hotelling and Bayesian observers modified to account for the spatial-frequency-selective channels in the human visual system. The theory behind these observer models is briefly reviewed, and several psychophysical studies relating to the choice among them are summarized. Only the Hotelling model with channels is mathematically tractable in all cases considered here and capable of accounting for all of these data. This model requires no adjustment of parameters to fit the data and is relatively insensitive to the details of the channel mechanism. We therefore suggest it as a useful model observer for the purpose of assessing and optimizing image quality with respect to simple detection tasks.

Twist constraints on linker DNA in the 30-nm chromatin fiber: implications for nucleosome phasing

Previous work has shown that nucleosome repeat lengths, and hence linker DNA lengths, are preferentially quantized to a set of values differing by integral multiples of the helical twist of DNA. An explanation was proposed in which this preferential quantitation is due to twist constraints on linker DNA arising from nucleosome-nucleosome interactions in folded chromatin. Here we report the results of a study, using ethidium intercalation, designed to test whether twist constraints do indeed exist. Electron microscopy reveals that ethidium intercalation causes decondensation of dinucleosomes. Direct measurement of the free energy of intercalation by fluorescence spectroscopy reveals competition between chromatin folding and ethidium intercalation. Results from other laboratories establish that these effects of ethidium are due to ethidium-induced changes in the twist of linker DNA, and not to a variety of other possible effects. We conclude that twist constraints on linker DNA do exist. These may explain the observation of preferentially quantized linker DNA lengths. Implications of these results for mechanisms of nucleosome phasing and the mechanisms of drug action are discussed.

A recent epidemic of acute hemorrhagic conjunctivitis

The coxsackievirus A24 variant was implicated in four of six major acute hemorrhagic conjunctivitis outbreaks in Singapore since its discovery in 1970. Hela cell suspension in 24-well flat-bottom tissue culture plates was a satisfactory alternative to monolayer cells grown in test tubes for virus isolation. Respiratory illness occurred in 20 of 98 patients with acute hemorrhagic conjunctivitis. Apart from conjunctival secretions, respiratory and oral transmission of coxsackievirus A24 variant would explain the rapid and extensive spread of acute hemorrhagic conjunctivitis during an outbreak.

Magnetic resonance imaging of a symptomatic meniscal ossicle

Meniscal ossicles are uncommon in humans. They are usually located in the posterior horn of the medial meniscus and are generally first observed on roentgenograms as intraarticular corticated bone densities. Many different entities appear similar to meniscal ossicles on roentgenography. Magnetic resonance imaging (MRI) can help to distinguish between these different entities and thereby assist in guiding treatment. Magnetic resonance imaging also can identify concurrent intraarticular pathology (e.g., meniscal tears), which may influence the choice of treatment. In a 29-year-old man, MRI confirmed the intrameniscal location of a corticated bone density seen in the posteromedial knee on roentgenograms. An associated medial meniscus tear was found at arthroscopy. The patient's symptoms were relieved after resection of the meniscal ossicle and the associated meniscal tear.

Mitogenic effect of neuropeptide Y in rat vascular smooth muscle cells

Neuropeptide Y (NPY) is a vasoconstrictor released with norepinephrine from perivascular sympathetic nerves. Since sympathetic nerves appear to play a role in vascular smooth muscle cell (SMC) hypertrophy, we studied the effects of NPY on proliferation of cultured rat aorta- and vena cava-derived SMC. Both cell types displayed high-affinity NPY binding sites with displacement characteristics of [Pro34]NPY > NPY(13-36) > NPY(18-36) in aorta and [Pro34]NPY = NPY(13-36) = NPY(18-36) in the vena cava. Incubation with NPY (50-1000 nM) for 48 h increased by up to twofold cell number and [3H]-thymidine incorporation in both cell types (aortic more sensitive to NPY than venous). Following incubation with NPY, the disappearance of NPY immunoreactivity (-IR) from media was markedly delayed in the presence of SMC, and cell content of NPY-IR increased in a dose-dependent manner, indicating that SMC either diminish degradation of the peptide (possibly by internalization) or secrete endogenous NPY (or both). Structure-activity relationship studies with NPY(18-36) indicated involvement of Y1 receptors in mitogenesis. Thus, NPY has a mitogenic effect (probably mediated by Y1 receptors) and, therefore, may be a sympathetic trophic factor involved in vascular hypertrophy.

Complete Gabor transformation for signal representation

Properties of the Gabor transformation used for image representation are discussed. The properties can be expressed in matrix notation, and the complete Gabor coefficients can be found by multiplying the inverse of the Gabor (1946) matrix and the signal vector. The Gabor matrix can be decomposed into the product of a sparse constant complex matrix and another sparse matrix that depends only on the window function. A fast algorithm is suggested to compute the inverse of the window function matrix, enabling discrete signals to be transformed into generalized nonorthogonal Gabor representations efficiently. A comparison is made between this method and the analytical method. The relation between the window function matrix and the biorthogonal functions is demonstrated. A numerical computation method for the biorthogonal functions is proposed.

[Diagnosis and treatment of blunt renal injury]

157 renal injury cases (22.2%) of 708 blunt abdominal injury cases admitted at our hospital from January, 1981 to April, 1991 were evaluated. The results suggested that large dose IVP have certain limitations, while modern ultrasound findings have important practical value. We think that the patients with renal injury more than 3 degree must be operated immediately. Nephrectomy may be considered on injured kidney if the contralateral renal function is normal, in order to avoid late complications. In cases of using inosine, dopamine and large furosemide during operation, the time lag of indicamine presenting in urine is helpful for judging and protecting contralateral renal function.

Decreased collagen gene expression and absence of fibrosis in thyroid hormone-induced myocardial hypertrophy. Response of cardiac fibroblasts to thyroid hormone in vitro

The regulatory effects of thyroid hormone on biosynthesis of myocardial proteins that originate from cardiac myocytes are well established. Little is known, however, of regulatory effects of thyroid hormone on interstitial proteins. In this study we examined the effects of thyroid hormone on collagen gene expression in thyroid hormone-induced myocardial hypertrophy and the response of cardiac fibroblasts to thyroid hormone in culture. Adult male Sprague-Dawley rats were treated intraperitoneally with L-thyroxin (10 micrograms/100 g body wt) for 2 hours or 1, 2, 3, 6, 12, or 14 days. Northern blot analysis of RNA from total ventricular tissue showed that after 2 hours of treatment, the abundance of mRNA for pro alpha 2(I) collagen decreased by 53% (p less than 0.05) and reached the lowest level (60% decrease, p less than 0.02) at day 1, remained diminished at day 3, and then gradually returned toward normal levels. After transient transfection of chimeric DNA containing collagen type I promoter-chloramphenicol acetyl transferase (CAT) gene into the thyroxin-treated cardiac fibroblasts, the level of CAT activity decreased significantly. Treatment of cardiac fibroblasts in culture (10 nM L-thyroxin) resulted in a 33% (p less than 0.005) decrease in the abundance of mRNA for pro alpha 2(I) collagen. The stability of the mRNA for pro alpha 2(I) collagen in cardiac fibroblasts, as measured by mRNA half-life, was slightly (16.6%) decreased by thyroid-hormone treatment. Collagen synthesis as shown by immunofluorescent staining of intracellular collagen in cultured fibroblasts and in frozen sections of myocardium was also diminished.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of interleukin-1 production by microglia in culture

The production of interleukin-1 (IL-1) by cultured neonatal rat microglia was studied using the D10 cell assay. The results show that IL-1 was secreted in response to lipopolysaccharide (LPS) in a dose- and time-dependent fashion. IL-1 production was specific to microglia and was not induced in astrocytes. Indomethacin, which is known to modulate the release of IL-1 from monocytes, had no effect on LPS-stimulated microglia. Aging of the microglia from two weeks to 4 weeks in culture, however, reduced the release of IL-1 in response to LPS. Our data indicate that microglia are a major source of IL-1 and that the release of IL-1 depends on the presence of inflammatory mediators such as LPS and the age of the culture.

Regulation of microglial function by interferons

Cultured neonatal rat microglia were pretreated with varying doses of either purified interferon (IFN) alpha/beta or recombinant IFN gamma for 24 or 48 h and the following functional parameters examined; superoxide anion production, interleukin-1 secretion and chemotaxis. IFN gamma produced a marked increase in superoxide anion levels when PMA was used to initiate superoxide anion production but had no effect in OPZ-stimulated microglia. Treatment with IFN alpha/beta potentiated superoxide anion production in both PMA and OPZ-stimulated cells. Interleukin-1 activity was decreased by treatment with IFN gamma for 24 h while IFN alpha/beta increased IL-1 activity at 48 h. Removal of serum from the treatment media prevented the action of IFN alpha/beta on IL-1 production. Treatment with IFN alpha/beta or gamma decreased chemotaxis of microglia in response to zymosan activated serum. The data indicate that IFN gamma and alpha/beta can regulate microglial function and that this regulation may differ from that seen for other monocytically derived macrophages.

Transmitted and tuning characteristics of birefringent filters

Transmission formulas and transmission curves of birefringent filters when the optic axis is not in the plane of the filter plates are given and discussed in detail. The optimum parameters of birefringent filters, such as the most suitable ratio of thicknesses, tuning angles, and plate thicknesses, are obtained. As far as we know this is the first design of birefringent filters used in a tunable laser pumped by a quasi-cw source.

Decreased collagen mRNA and regression of cardiac fibrosis in the ventricular myocardium of the tight skin mouse following thyroid hormone treatment

OBJECTIVE

The aim was to study the effect of thyroid hormone on collagen gene expression in the myocardium of the tight skin mouse (TSK), a genetic model of myocardial fibrosis.

METHODS

Heterozygous male (TSK/+) (n = 20) and normal (+/+) homozygous mice (n = 20), 1.5-2 months old of the C57 BL/6 strain were studied. Ventricular hypertrophy following thyroid hormone treatment (L-thyroxine, 10 micrograms.100 g-1 body weight daily intraperitoneally) was examined by measurement of the heart weight/body weight ratios and histological changes. Expression of fibrillar collagen types I and III in the ventricular myocardium was examined by measurement of the abundance of their respective mRNAs. Collagen synthesis was examined by measurement of hydroxyproline. Deposition of collagen types was evaluated by immunofluorescence staining. Expression of non-collagenous proteins, sarcomeric and cytoskeletal actin, was measured at the mRNA level.

RESULTS

After 12 days of treatment ventricular hypertrophy was induced in the heart of the TSK mice. The results of northern hybridisation analyses showed that in the hearts of TSK mice 24 h after thyroxine treatment the abundance of mRNA for pro alpha 2 (I) collagen was decreased by 32% (p less than 0.05), pro alpha 1 (III) collagen by 47% (p less than 0.002), cytoskeletal actin by 50% (p less than 0.005), and sarcomeric actin mRNA by 34% (p less than 0.01) compared to the untreated TSK mice. The abundance of mRNA for pro alpha 2 (I) and pro alpha 1 (III) collagens in the thyroxine treated TSK mice were nearly comparable to that in normal homozygous mice. In TSK mice which were treated for 12 d, collagen content of the ventricular myocardium, as determined by hydroxyproline measurements, was decreased by 22.5% (p less than 0.01) compared to that in the heart of normal homozygous mice.

CONCLUSIONS

Effects of thyroid hormone on ventricular gene expression in TSK mice result in a diminished collagen mRNA and collagen content and the disappearance of cardiac fibrosis. Thyroid hormone may selectively prevent the induction of cardiac fibrosis and play an important role in regression of cardiac fibrosis via endocrine pathways.

CSF chromogranin A-like immunoreactivity in schizophrenia. Assessment of clinical and biochemical relationships

Chromogranin A (CgA) is co-released with catecholamines and peptides and has a wide distribution in the brain. Chromogranin A provides a measure of tonic arousal. CSF CgA-like immunoreactivity (CgA-LI) was studied in 42 drug-free male schizophrenic patients. 33 of these patients were first studied during chronic haloperidol maintenance treatment. Withdrawal from haloperidol maintenance treatment was associated with a significant increase in CSF CgA-LI, particularly in the patients who did not relapse. Contrary to expectation CSF CgA-LI was higher in drug-free patients who slept longer the night before the lumbar puncture. Significant relationships were observed between CSF CgA-LI and CSF homovanillic acid, acetylcholinesterase, neuropeptide Y-LI and 5-hydroxy-indole acetic acid, but not with CSF norepinephrine or 3-methoxy-4-hydroxyphenylglycol. Ventricular brain ratios correlated negatively with CSF CgA-LI levels.

Abnormal production of interleukin-1 by microglia from trisomy 16 mice

The production of interleukin-1 (IL-1) was examined in cultured CNS microglia obtained from trisomy 16 (Ts16) fetal mouse brain, a model system for studies relevant to Down syndrome (DS). When compared to microglia from their normal littermates, Ts16 microglia produced significantly higher levels of IL-1 activity both before and following stimulation with lipopolysaccharide (LPS). IL-1 release was stimulated by alpha/beta interferon (IFN) in the normal but not Ts16 microglial cultures. The overall level of IL-1 production in normal littermates, however, was still less than that seen in Ts16. Thus, microglia from Ts16 mice may function in an inappropriate manner and, if this abnormality occurs in vivo, may have wide ranging effects on a developing nervous system.

Linker DNA bending induced by the core histones of chromatin

We have previously reported that ionic conditions that stabilize the folding of long chromatin into 30-nm filaments cause linker DNA to bend, bringing the two nucleosomes of a dinucleosome into contact [Yao, J., Lowary, P. T., & Widom, J. (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 7603-7607]. Dinucleosomes are studied because they allow the unambiguous detection of linker DNA bending through measurement of their nucleosome-nucleosome distance. Because of the large resistance of DNA to bending, the observed compaction must be facilitated by the histones. We have now tested the role of histone H1 (and its variant, H5) in this process. We find that dinucleosomes from which the H1 and H5 have been removed are able to compact to the same extent as native dinucleosomes; the transition is shifted to higher salt concentrations. We conclude that histone H1 is not essential for compacting the chromatin filament. However, H1 contributes to the free energy of compaction, and so it may select a single, ordered, compact state (the 30-nm filament, in long chromatin) from a family of compact states which are possible in its absence.

[Practical value of prostatography]

From September 1988 to September 1989 perineal puncture prostatography with 60% urografin was performed in 21 patients with the prostate enlargement. Prostatographic findings suggested that 15 patients had benign prostatic hyperplasia and 6 had prostatic cancer. The diagnosis had been histologically proved after prostatectomy in 19 cases. The procedure was easily and safely conducted at outpatient clinic without complications. We believe that prostatography is useful in differential diagnosis of prostatic diseases and in selecting operative methods.

The effect of xanthine/xanthine oxidase generated reactive oxygen species on synaptic transmission

The effect of reactive oxygen species generated by the interaction of xanthine and xanthine oxidase on synaptic transmission was examined at the squid giant synapse and the lobster neuromuscular junction. Exposure of these synaptic regions to xanthine/xanthine oxidase produced a significant depression in evoked release, with no change in either resting membrane properties or in the action potential. Addition of catalase to the xanthine/xanthine oxidase-containing media partially blocked the synaptic depression, indicating that H2O2 contributes to the synaptic changes induced by exposure to xanthine/xanthine oxidase. H2O2 applied directly to the perfusing media also produced a decrease in synaptic efficacy. The results demonstrate that reactive oxygen species, in general, depress evoked synaptic transmission.

Direct detection of linker DNA bending in defined-length oligomers of chromatin

Linker DNA, which connects between nucleosomes in chromatin, is short and, therefore, may be essentially straight and inflexible. We have carried out hydrodynamic and electron microscopic studies of dinucleosomes--fragments of chromatin containing just two nucleosomes--to test the ability of linker DNA to bend. We find that ionic conditions that stabilize the folding of long chromatin cause linker DNA in dinucleosomes to bend, bringing the two nucleosomes into contact. The results uphold a key prediction of the solenoid model of chromosome folding and suggest a mechanism by which proteins that are separated along the DNA can interact by direct contact.

Neuropeptide Y-like immunoreactivity in schizophrenia. Relationships with clinical measures

Neuropeptide Y-like immunoreactivity (NPY-li) was measured in CSF of 35 drug-free chronic schizophrenic patients. Compared to a group of drug-free controls, CSF NPY-li was significantly higher in these patients. CSF NPY-li decreased with age and longer duration of illness. Measures of structural brain abnormalities on CT scans were significantly associated with lower CSF NPY-li. Relationships between NPY-li and schizophrenic behavior, i.e. positive symptoms, were observed only in the clinically stable (nonrelapsed) drug-free patients. In 31 of the patients CSF was obtained before and after withdrawal from haloperidol maintenance treatment. This withdrawal from haloperidol treatment was associated with a significant increase in CSF NPY-li. There was no significant difference in CSF NPY-li between patients who did and those who did not relapse within 6 weeks following haloperidol withdrawal. The present findings suggest a relationship of CSF NPY-li with various aspects of schizophrenia.

Chemotaxis by a CNS macrophage, the microglia

Microglia demonstrate many characteristics similar to those seen in monocytes and tissue-specific macrophages, including phagocytosis, production of oxygen radicals, and growth factors and expression of MHC antigens. We have examined the ability of microglia, cultured from the cerebral cortices of neonatal rats, to demonstrate another important functional characteristic of monocytic-derived cells, that is, chemotaxis. Our results show that cultured rat microglia demonstrate chemotaxis to complement dependent chemoattractants such as recombinant C5a, zymosan activated serum, and to rat serum as well as to transforming growth factor-beta, a chemoattractant produced by platelets. Microglia fail to migrate to bacterial dependent chemoattractants such as the N-formyl peptides. The failure to respond is not dependent on maturational state of the microglia. Treatment with DMSO or casein, agents known to induce morphological and functional changes in cultured microglia reminescent of a "resting" and an "activated" macrophage, respectively, do not alter the response to fMet-Leu-Phe. In addition, the chemotactic response to serum in DMSO or casein-treated cells is the same as the response seen in untreated day 10 cultured microglia or untreated age-matched controls. The ability of microglia to migrate in response to inflammatory mediators suggests that these cells can move to sites of injury, thereby enabling them to participate in an inflammatory response.

Stem fracture incidence in Trapezoidal-28 stainless steel hip arthroplasty

From 1970 to March 1978, 716 forged stainless steel Trapezoidal-28 (T-28) total hip arthroplasties were performed at the authors' institution with a follow-up period from one to 15 years (mean, 64 months). There were 13 (1.8%) stem fractures and one (0.1%) neck fracture. Average time to fracture was 95 months. All fractures occurred in stems implanted before 1976, using early femoral acrylic stem fixation techniques. Stem fracture was related to time of surgery, stem size, patient height, patient weight (for males), and patient age. Survivorship analysis predicted an overall ten-year fracture rate of 4%, and a ten-year rate of 5% for T-28 stems implanted before 1976. There have been no reported fractures in the 204 T-28 stainless steel prostheses implanted since 1976. The mean patient follow-up period for the T-28 stems implanted after 1975 was 52 months, and only 16 patients have been followed for nine years or more. Thus, a longer patient follow-up period is needed in the post-1975 group in order to determine the long-term fracture rate in this group. However, the major difference between this group and the early group is the use of an improved cementation technique, as well as the use of larger prostheses when possible. There was no material or manufacturing change until the introduction of the TR-28 prostheses in 1978.

Norepinephrine in acute exacerbations of chronic schizophrenia. Negative symptoms revisited

In recent years the dopamine hypothesis has failed to explain the complexities of schizophrenia. Because both negative symptoms and noradrenergic activity appear to increase with psychotic relapse, we studied negative symptoms, psychosis, cerebrospinal fluid norepinephrine, and cerebrospinal fluid monoamine metabolites in 32 male patients with a DSM-III diagnosis of schizophrenia while both receiving and not receiving long-term haloperidol treatment. Drug-free cerebrospinal fluid norepinephrine and 3-methoxy-4-hydroxyphenylglycol levels correlated significantly with the severity of negative symptoms and psychosis ratings. When the patients were divided into those who did and did not relapse while not receiving the drug, significant positive correlations between negative symptoms and cerebrospinal fluid norepinephrine and 3-methoxy-4-hydroxyphenylglycol were observed only in the patients who relapsed. Non significant but negative correlations were observed between the same variables in the nonrelapsers. Thus, increased norepinephrine activity in drug-free patients is associated with intensification of schizophrenic symptoms without necessarily causing the symptoms.