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.

CSF norepinephrine in schizophrenia is elevated prior to relapse after haloperidol withdrawal

Thirty-two male DSM-III diagnosed schizophrenic patients received a lumbar puncture (LP) during chronic haloperidol treatment that was followed by replacement with placebo for up to 6 weeks. Fourteen patients relapsed on placebo within 6 weeks. Patients received a second LP at the time of relapse or at the end of 6 weeks if they had not relapsed. Bunney-Hamburg Global Psychosis Ratings of the day and the hours of sleep of the night before the LP were obtained, as were the Brief Psychiatric Ratings Scale (BPRS) ratings during the week of the LPs. CSF norepinephrine (NE), 3-methoxy-4-hydroxyphenylglycol (MHPG), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5 HIAA) concentrations were measured with high-pressure liquid chromatography (HPLC). Patients who relapsed had significantly higher CSF NE levels on and off haloperidol than patients who did not relapse. CSF MHPG was higher in the relapsers in the drug-free condition only, but CSF HVA and 5-HIAA were not significantly different in either condition. In the drug-free relapsed patients, CSF NE correlated significantly with the psychosis ratings of the day and hours of sleep the night prior to the LP. Our data indicate that elevated CSF NE levels during neuroleptic treatment may predict behavioral decompensation after discontinuing the medication.

Complete atrioventricular block, retrograde atrial activation and intra-atrial block

A case of complete atrioventricular block, retrograde atrial activation, and intra-atrial block was reported. Inhomogeneous inhibition of the atrioventricular junction and the so-called summation of impulses may both act together to make retrograde conduction possible when third-degree atrioventricular block was present. In lead 2, P waves were dome-shaped, and in lead V1, P waves were biphasic; narrow and peaked P waves intermittently appeared, denoting third-degree intra-atrial block. The peaked P waves signified that the right atrium was activated while the left atrium was not depolarized.

Survival analysis of T-28 hip arthroplasty with clinical implications

Seventeen years after its introduction, the T-28 and its successor (the TR-28) have proved to be a successful arthroplasty system, with very low long-term socket and femoral loosening rates, especially in older patients. The 10-year revision rate for aseptic loosening of the socket is only 2 per cent. This form of conventional cemented total hip replacement has provided pain relief and improved function in many individuals who have exhausted nonoperative treatment alternatives. Although there are still unsolved long-term problems for the young active patients, cemented hip arthroplasty continues to play an important role in joint replacement, and remains the treatment of choice in older and relatively inactive patients.

Tomography in a juvenile Tillaux fracture

Juvenile Tillaux fractures are Salter-Harris Type III physeal fractures involving the lateral weight-bearing surface of the distal tibia. A recent case demonstrates the usefulness of tomography as an adjunct to routine radiographs as a more accurate means of diagnosing the amount and direction of fracture displacement, a critical factor when treatment decisions are made.

Articular sporotrichosis

Sporotrichosis is a fungal disease caused by Sporothrix schenckii, which is seen worldwide. Infection usually involves cutaneous and subcutaneous tissues. Articular involvement is rare. A 29-year-old man with ankle sporotrichosis is reported to demonstrate the differential diagnosis and treatment.

Epitope diversity of angiotensin II analysed with monoclonal antibodies

The antigenic heterogeneity of angiotensin II (AII) was studied with monoclonal antibodies. Twelve antibodies were produced and characterized. Association constants for AII varied from 1.2 X 10(8) to 1.1 X 10(10) M-1. The fine specificity of the Mab was studied by immunoenzymoassay using solid-phase AII. Using AII analogues in binding inhibition experiments, three groups of specificity could be characterized: (1) five antibodies reacted only with peptides in which phenylalanine is the carboxy terminal aminoacid; for two of these antibodies, tyrosine4 is closely associated with the binding site, since iodine labelling suppresses reactivity; (2) two antibodies also required phenylalanine in position 8, but, in addition, reacted with AI, a decapeptide in which phenylalanine is not terminal; (3) five antibodies reacted with analogues in which phenylalanine had been substituted for another amino acid. In addition, studies in which binding of a biotinylated Mab to solid-phase AII was analysed in the presence of various unlabelled Mab suggest further antigenic heterogeneity of AII.

Network security considerations in BLN

In a heterogeneous computer network, resources on each node are protected by the local security mechanism. Network services allow local resources to be accessed remotely from other nodes. Without appropriate network security measures, each node is vulnerable to attack from the network. This paper analyzes the heterogeneous Bell Labs Network (BLN) environment and lists the potential network security risks. By assessing the risks, counter-measures are proposed for minimizing potential exposure. These counter-measures are part of a global network security mechanism being implemented for BLN.

[Clinical effects in 1136 cases of Beijing silicon rubber IUD and its effect on the endometrium]

Beijing Silicon Rubber IUD was designed by Xuan Wu Hospital and Beijing Silicon Rubber Manufacturing Research Institute in 1980. Animal experiments of the silicon rubber were done, and toxic effect studied before clinical use. 1136 cases were reported at the end of 12 months by 6 hospitals in Beijing. The followup rate was 93.75%. Life table of 12 months showed the cumulative continuation rate of the IUD was 82.45%, pregnancy rate 4.5%, expulsion rate 8.49%, removal for medical cause 3.9%, and removal for personal reasons 0.64%. Among the side effects, menstrual irregularity was 5.03%, blood discharge 6.35%, dysmenorrhea 11.95%, backache 31.1%, and leucorrhea 18.12%. Menstrual blood loss was measured in 30 cases before and after 1, 2, 3 months of insertion. The mean blood loss before insertion was 51.96 ml (51.71 +or- 15.95), while 1 month after insertion it was 62.9 ml (70.59 +or- 26.81), 2 months after insertion 71 ml, and 3 months after insertion 75 ml. The morphological endometrial change as compared with that by induced stainless steel ring is not much heavier especially in regard to glandular and stromal changes. The endometrial cytologic count of white cells of the IUD group (34 cases) in comparison with that of the control group (36 cases) was about twice as much in number. As Moyer reported, the endometrial cell count of IUD cases was about 6-10 times that of control cases. The authors consider that the cellular reaction of this IUD is not much greater than that of other types of IUDs.

Congenital intracardiac band: a rare cause of nonrheumatic combined aortic and mitral regurgitation

A patient had a congenital intracardiac band lying across the aortic valve that caused combined aortic and mitral valvular regurgitation. The band was excised, and the damaged aortic valve was replaced with a prosthesis. The case illustrates that not all congenital intracardiac bands are completely asymptomatic and not all bivalvular incompetence is rheumatic in origin.

Secundum atrial septal defect in the adult: repair using cardiopulmonary bypass in 133 patients

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