LTB4 production and lysosomal enzyme release by rat alveolar macrophages: effects of phagocytosis, receptor binding, and ionophore stimulation

We have previously shown that the predominant lipoxygenase product of arachidonic acid metabolism in rabbit alveolar macrophages is leukotriene (LT) B4. LTB4 was not detectable in normal unstimulated rabbit macrophages, but its production was increased following calcium ionophore A23187 stimulation, especially after in vivo activation of the immune system. In the present study, we describe that (a) rat alveolar macrophages produced LTB4 in response to natural, biological stimuli such as binding of Fc receptors and complement receptors, as well as zymosan phagocytosis and ionophore stimulation. In contrast, binding of lectin receptors such as concanavalin A and phytohemagglutinin failed to elicit significant increase of LTB4. (b) The predominant LT that was produced was LTB4 regardless of the type of stimulus. This pattern is similar to that of rabbit lung macrophages, but rat alveolar macrophages released higher quantities of LTB4, which can be easily quantitated by high-performance liquid chromatography (HPLC). (c) Phorbol myristate acetate by itself was a weak agonist for LTB4 release. Yet, in combination with a low dose of calcium ionophore A23187 it resulted in LTB4 production. (d) There was a general correlation between release of LTB4 and lysosomal enzymes. In other words, the stimulus that is effective for eliciting enzyme release was usually also effective in causing LTB4 production. (e) A considerable proportion of the LTB4 produced was retained intracellularly. This phenomenon was especially pronounced when zymosan was used as stimulus. (f) Despite the parallelism between LTB4 production and lysosomal enzyme release, the former probably does not regulate the latter. The time courses of their release are dissimilar, and nordihydroguaiaretic acid fails to inhibit lysosomal enzyme release by a dose markedly inhibiting LTB release. (g) Contrary to rabbit lung macrophages rat lung macrophages showed a predominance of lipoxygenase pathway over cyclooxygenase pathway following zymosan ingestion. However, macrophages from both species produced mainly cyclooxygenase products in response to exogenous arachidonic acid.

A transcriptional terminator is a novel element of the promoter of the mouse ribosomal RNA gene

Sequences flanking residue-168 of the mouse rRNA gene are essential to direct efficient transcription in transfected cells and are stimulatory in vitro on closed circular templates. This promoter domain evidently functions by the unprecedented mechanism of terminating polymerase I-directed transcripts. It inhibits transcripts from reading into the initiation region, acting cotranscriptionally to end these RNAs at residue--182 and release them from the template. Most likely, polymerases on tandem genomic rRNA genes are not released upon completing each 40-47S transcript, but traverse the entire spacer to the next promoter-terminator, where they are made available and positioned to favor reinitiation. Through such polymerase recycling, plus the binding of free polymerase, the rDNA promoters could achieve their characteristically high level of transcription.

Heavy charged particle therapy of bone and soft tissue sarcoma. A phase I-II trial of the University of California Lawrence Berkeley Laboratory and the Northern California Oncology Group

At the University of California Lawrence Berkeley Laboratory and the Northern California Oncology Group, a preliminary study of heavy charged particle radiotherapy in soft tissue and bone sarcoma has been carried out. Fifty-two patients with bone or soft tissue tumors were treated wholly or in part with heavy charged particles from 1978 to 1985. Eleven patients, considered inevaluable for purposes of this analysis, received less than 50 Gray-equivalents (GyE) because of the following: progressive disease (three patients); palliative treatment due to recurrent disease after previous radiation therapy (three patients); or since they were part of preliminary studies of relative biological effectiveness (RBE) (five patients). Forty-one patients received from 50 to 78.5 GyE, with a mean of 65 GyE. They had an average of 23 months follow-up, ranging from 4 to 78 months. In patients with paraspinal chondrosarcoma 9 of 11 had local control, with a mean follow-up time of 32 months. In the remaining patients with other histologies, 19 of 30 were controlled within the irradiated area, with a mean follow-up time of 20 months. Serious complications were encountered in the CNS (four patients), in the bowel (one patient), and in bone (one patient). Heavy charged particle radiotherapy appears to be of value in treating bone or soft tissue sarcoma; further trials are planned.

Work performance in the iron-deficient rat: improved endurance with exercise training

The effect of an endurance training regimen on muscle oxidative enzymes and work performance was studied in iron-deficient and -sufficient rats. Three-week-old male Sprague-Dawley rats (n = 40) were randomly assigned to diets containing either 6 mg iron/kg (iron deficient) or 50 mg iron/kg (iron sufficient). After 2 wk, each group of rats was further divided into untrained or endurance-trained subgroups. Training consisted of daily treadmill running of gradually increasing duration for a 1-mo period. After the training period, sedentary and endurance-trained iron-deficient rats were anemic (Hgb approximately 8 g/dl compared with 16 g/dl in the 2 control groups) and had significantly lower skeletal muscle cytochrome c concentration, cytochrome oxidase activity, and succinic oxidase activity compared with the iron-sufficient groups. In response to training iron-deficient rats also generally had a substantial increase in skeletal muscle oxidative enzymes (P less than 0.05), in contrast to iron-sufficient animals, in which there was little or no training effect. Work performance in response to training in the iron-deficient rats improved more than sixfold in an endurance type of exercise (P less than 0.05), but maximal oxygen consumption during a brief, intense type of exercise was not significantly affected. The results suggest that endurance training of iron-deficient rats results in a milder anemia and less drastic reduction of skeletal muscle oxidative enzymes which in turn allows better performance in an endurance type of exercise.

The biosynthesis of leukotriene B4, the predominant lipoxygenase product in rabbit alveolar macrophages, is enhanced during immune activation

Rabbit alveolar macrophages synthesize prostaglandins in response to various stimuli. We have previously shown that prostaglandin production was decreased in immunologically activated (live Bacillus Calmette-Guérin (BCG)-injected) animals. (Hsueh, W., Lamb, R. and Gonzalez-Crussi, F. (1982) Biochim. Biophys. Acta 710, 406-414). In the present study, we examined the lipoxygenase products of alveolar macrophages from normal and immunologically activated rabbits injected intravenously with live BCG or complete Freund's adjuvant. We found: unstimulated lung macrophages produced no detectable leukotrienes; the predominant lipoxygenase product upon stimulation was leukotriene B4; alveolar macrophages did not significantly degrade leukotriene B4 into its 20-hydroxy derivative, and the total degradation of leukotriene B4 during 90 min of incubation was minimal; the production of leukotriene B4 reached the peak at 30 min after A23187 stimulation, while zymosan caused a much slower and smaller release; following stimulation, immunologically activated lung macrophages produced more leukotriene B4 than resident macrophages. It is possible that the increased leukotriene B4 production in immunologically activated lung macrophages was related to the immunoregulatory function of this substance, such as enhancing cytotoxicity, interferon production and proliferation of suppressor-cytotoxic T cells.

Effects of training and exhaustive exercise on the mitochondrial oxidative capacity of brown adipose tissue

Oxidation of pyruvate, alpha-ketoglutarate, palmitoylcarnitine, succinate, and ferrocytochrome c by interscapular-brown-adipose-tissue (BAT) mitochondria of untrained and trained rats were measured at rest and after running to exhaustion. At rest, BAT mitochondria from trained rats showed significantly lower activities (less than 50%) for the oxidation of all the substrates. In untrained rats the activities of the enzymes for the oxidation of all the substrates except pyruvate and succinate were lower at exhaustion compared to the resting state when expressed on a per-gram-fresh-weight basis. In trained rats all of the enzyme activities increased as a result of exhaustive exercise. These differences between the two groups of rats in the post-exercise changes in oxidative capacities suggest that following an initial adaptation, resulting in a large decrease in mitochondrial oxidative activity, training protects the residual oxidative pathways against exercise-induced inactivation. These data show that unlike exposure to cold, or overfeeding, a physiological stimulus such as exercise reduces the oxidative capacity of BAT, and therefore may reduce the thermogenic activity of the tissue in endurance-trained rats as has been addressed in the scientific literature.

Detection and quantification of previous myocardial infarction by exercise-redistribution tomographic thallium-201 scintigraphy

Although myocardial perfusion scintigraphy at rest accurately diagnoses myocardial infarction (MI), the prevalence and size of previous MI is overestimated by exercise-redistribution thallium-201 studies. A new, quantitative approach to the analysis of tomographic thallium-201 scintigrams was developed in order to determine whether the presence and extent of MI could be determined. Sixty patients undergoing cardiac catheterization for chest pain syndromes, including 28 with previous MI, were studied by exercise and 3-hour delayed thallium-201 scintigraphy, with use of the 7-pinhole tomographic technique. Circumferential profiles of the postexercise and 3-hour radiotracer distribution were generated from apical, midventricular and basal left ventricular slices. The 3-hour profile fell below normal limits in 24 of 28 patients (86%) with remote MI, but was also abnormal in 9 of 22 patients (41%) with coronary disease but no MI. All missed MIs were either inferior or subendocardial and were associated with normal ejection fractions. To distinguish between MI and slowly resolving ischemic defects, a quantitative approach was used. MI area was calculated as the area in which the 3-hour profile fell below the 3-hour normal limits, and a redistribution area in the MI zone was determined as the area between the postexercise and 3-hour profiles in the region where the 3-hour profile was abnormal. The MI area was 1,000 +/- 980 units in patients with MI, vs 79 +/- 120 units in patients without MI (p less than 0.001), whereas the redistribution area was higher in patients without MI (1,240 +/- 810 vs 430 +/- 400 units, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitative analysis of seven-pinhole tomographic thallium-201 scintigrams: improved sensitivity and estimation of the extent of coronary involvement by evaluation of radiotracer uptake and clearance

Recent studies have shown that the sensitivity of conventional thallium-201 scintigraphy can be increased by the quantitative assessment of myocardial radiotracer clearance rates in conjunction with the evaluation of radionuclide uptake. In this study, a similar analysis of tomographic scintigrams was performed to determine the feasibility and value of this approach, particularly in estimating the extent of disease and detecting three vessel coronary involvement. Seventy patients undergoing cardiac catheterization for chest pain were studied by exercise and 3 hour delayed thallium-201 scintigrams using the seven-pinhole tomographic technique. Each study was evaluated by visual inspection of the tomographic sections and quantitative analysis. The latter approach consisted of comparing circumferential profiles of the initial post-exercise radionuclide uptake and the 3 hour clearance rates generated from each of three left ventricular slices with similar profiles representing the lower 95% confidence limits derived from 15 middle-aged volunteers. An abnormality was considered present when a patient's profile fell below these limits for a 30 degrees arc, and was ascribed to disease in a particular artery when it involved that vessel's usual distribution. Among the 61 patients without apparent primary myocardial or valvular disease, the diagnostic sensitivity of thallium scintigraphy was increased from 86% (43 of 50) to 96% (48 of 50) without a change in specificity (both 9 of 11 or 82%). More importantly, the quantitative approach permitted detection of 85% (107 of 126) of significantly obstructed coronary vessels compared with 47% (59 of 126) by visual analysis (p less than 0.001), again without sacrificing specificity (85 versus 87%).(ABSTRACT TRUNCATED AT 250 WORDS)

A simple method for generation of antibodies with specificity for 1,25-dihydroxyergocalciferol and 1,25-dihydroxycholecalciferol

A simple method for production of antisera with high affinity and selectivity for 1 alpha, 25-dihydroxyergocalciferol and 1 alpha, 25-dihydroxychole-calciferol is described. 1 alpha-Hydroxy-25,26,27-trisnorcholecalciferol-24-oic acid was coupled directly to bovine serum albumin. Rabbits immunized with this conjugate rapidly produced antibodies that bound 3H-1 alpha,-25-dihydroxycholecalciferol with high affinity and demonstrated nearly equal reactivity with 1 alpha, 25-dihydroxyergocalciferol and poor reactivity with 25-hydroxycholecalciferol; 24,25-dihydroxycholecalciferol; 25,26-dihydroxycholecalciferol; and 1 beta,25-dihydroxycholecalciferol. The use of one of these antisera has led to the development of a specific assay for 1 alpha,25-dihydroxyergocalciferol and 1 alpha,25-dihydroxycholecalciferol in human serum.

Computed tomography and ultrasound of retained placenta from abdominal pregnancy

The computed tomographic (CT) and ultrasound findings in a case of retained placenta from an abdominal pregnancy are presented. To our knowledge, this is the first published report of CT findings in retained placenta of abdominal pregnancy. The complementary role of CT and ultrasound in managing this disorder are discussed.

Enhancement in immunity of tumor bearing mice by immunization against prostaglandin E2

C57Bl/6 mice bearing a palpable Lewis lung carcinoma (LLC) were immunized against prostaglandin E2 (PGE2) in order to prevent the immune suppression typical of tumor bearers. Proliferation in response to concanavalin A (Con A) by normal spleen cells cultured in the presence of PGE2 or by spleen cells of LLC-bearing mice cultured with Con A alone was suppressed. However, the mitogenic response of spleen cells from PGE2 immunized LLC-bearing mice was only partially suppressed. The random migration of normal macrophages cultured in the presence of PGE2 or of macrophages from LLC-bearing mice cultured in medium alone was enhanced when compared to the random migration of normal macrophages cultured in the absence of PGE2. In contrast, the random migration of macrophages obtained from PGE2 immunized LLC-bearing mice was the same as that of normal macrophages cultured in the absence of PGE2.

Evaluation of an automated radioimmunoassay system: the ARIA II

The ARIA II is an automated instrument for the quantitation by radioimmunoassay of the following constituents: digoxin, cortisol, thyroxine, T3 uptake, T3 RIA, estriol, and progesterone, its methodology uses a specific antibody covalently bonded to a solid support in a reusable antibody chamber. We evaluated the assay system for the first three constituents listed above. Coefficients of correlation with conventional manual methods were: thyroxine-0.9797; digoxin-0.9871; and cortisol-0.9727. Inter-assay variations using a commercially available tri-level control serum were as follows: thyroxine-5.4 to 10.3%; digoxin-3.7 to 6.3%; cortisol-5.2 to 8.4%. The ARIA II is not a discrete analyzer, and an estimate of carryover was significant only on low-to-high for the thyroxine assay. ARIA II assays are approximately one-half the cost of manual assays. Time studies indicate the ARIA II to be most suited to laboratories of low or moderate volume.

Inherited canine giant axonal neuropathy

To date, a single case of canine giant axonal neuropathy (GAN) has been recorded. The present report describes the disease in 3 more dogs from the second litter produced by the parents of the original case. Regular clinical and electrophysiological examinations were carried out on all 11 dogs of the second litter. At 14--16 months of age, 3 dogs developed slight posterior ataxia which progressed to a severe lower motor neuron disturbance involving only the hind legs. During this period, each dog began to regurgitate food as a result of megaesophagus. From 12 months of age, there was a progressive reduction in the amplitude of the evoked muscle action potential. Biopsy of the tibial fascicular nerve at 16 months of age confirmed that all 3 dogs had GAN, with numerous swollen unmyelinated fibers and less frequent enlarged myelinated fibers containing accumulated neurofilaments.

Social relationships, adversity and neurosis: an analysis of prospective observations

The effect of deficiencies in social relationships has been studied prospectively in a community sample. In the half who were exposed to the higher level of adversity, these deficiencies explained 30 per cent of the variance in neurotic symptoms four months later. They explained only 4 per cent in those with lower adversity. Contrary to expectation, it was not the lack of relationships, but perception of these as being inadequate under adversity, which had by far the stronger predictive power. This may mean that actual conditions in the immediate social environment are not important for neurosis. Instead, intrapsychic and personality factors may have a much stronger effect.

The reliability of reports of early separations

A random sample of adult community residents (n 244) was asked about separations in their childhood. Eight months later, the group was asked the same questions again. Only the death of a parent and the break-up of the parental marriage were reported with high reliability. These events made up one third of all reported separations.

Mental health and the use of alcohol, tobacco, analgesics and vitamins in a secondary school population

A survey of mental health in relation to patterns of alcohol, tobacco, pharmaceutical drug use and reducing diets was carried out in six Hobart high schools and matriculation colleges. A response rate of 89% was achieved, yielding a sample of 2,419 teenagers. Psychiatric disorder was assessed by the 60-item General Health Questionnaire. A statistically significant association was found between the probability of psychiatric disturbance and the use of alcohol, cigarettes, analgesics, vitamin supplements and weight-reducing diets.

Personal networks and the schizophrenias

It is likely that certain elements in the individual's current social environment act causally in the onset of schizophrenia. The construct known as 'social support' has recently been invoked as one such element which, when deficient, may be causal factor. The evidence for this is unsatisfactory and likely to remain so. For clinical purposes, it would be more useful to look at the effect of social relationships in secondary and tertiary prevention.

Measuring social relationships. The Interview Schedule for Social Interaction

It is generally recognized that social relationships occupy a central position in psychiatry. To examine the role of social relationships in the onset of minor psychiatric morbidity it is necessary to construct an instrument which will meet the need for a valid, reliable and comprehensive index of social relationships. Such an instrument has now been developed and used in a sample of the general population. The Interview Schedule for Social Interaction arose from a research need, and was constructed to assess the availability and perceived adequacy for any individual of a number of facets of social relationships. These consist both of persons and of the provisions obtained through them. Data from a general population sample suggest this instrument to be sufficiently valid and reliable, and also sensitive to predictable variations between sociodemographic groups, to justify its use in clinical and epidemiological studies, both in psychiatry and general medicine.

Ultrasound as a diagnostic aid in the evaluation of popliteal swelling

Ultrasound (US), because of its ability to distinguish cystic from solid tissue, is an ideal tool for diagnosing masses in the popliteal fossa. Five cases are presented. Two cases show the typical ultrasound images in the most common popliteal mass, a cyst. A third case significantly points out the necessity of further investigations if the US findings are atypical of a simple cyst and the patient is symptomatic. A fourth case demonstrates that the US image can distinguish an aneurysm of the popliteal artery from a cyst. A fifth case demonstrates that a solid tumor in the popliteal fossa, in contrast to that of a cyst, has a characteristic US image. Ultrasound is a simple, quick, noninvasive outpatient procedure available to almost every physician. In most instances, US appears to be the diagnostic procedure of choice following conventional radiography in the evaluation of swelling in the popliteal fossa.

Social relationships, adversity and neurosis: a study of associations in a general population sample

A standardized study of the point prevalence of non-psychotic disorder was carried out on a systematic sample of Canberra residents (N = 756). Rates were estimated for PSE CATEGO diagnoses and the Index of Definition. The association between neurosis and deficiencies in social relationships was examined, using the Interview Schedule for Social Interaction (ISSI). An objective measure of exposure to adversity was also obtained at interview. Both attachment and social integration (affectionally close and more diffuse relationships) were found to be negatively associated with neurosis. This association holds in its own right, in addition to an interaction with the load of adversity. The associations are weaker for men. The significance of this work lies in its demonstration of an association between neurosis and the lack of social ties, and in its attempt to obtain a specification of those elements in social relationships which, when deficient, may be associated with neurosis. The direction of causality has now to be investigated.