Comparison of preoperative characteristics of men and women undergoing coronary artery bypass grafting (the Post Coronary Artery Bypass Graft [CABG] Biobehavioral Study)

A cohort of 759 coronary artery bypass grafting (CABG) patients (269 women and 490 men) was enrolled in the prospective POST CABG Biobehavioral Study at 5 clinical centers in the United States and Canada. Sociodemographic and medical data were obtained by interview and from medical charts. Health-related quality of life and psychosocial data were ascertained preoperatively by interview and questionnaire for those patients whose condition allowed preoperative assessment and was compared among patients from hospitals enrolling both male and female patients (143 women and 267 men). Women enrolled in the Biobehavioral Study were older than men (65.4 +/- 9.0 vs 61.8 +/- 9.7 years, p < 0.001) and more likely to have a preoperative medical condition which precluded biobehavioral evaluation (47% vs 34%, p < 0.001). Women were less likely to be high school graduates (59% vs 74%, p < 0.001), were less likely to be earning > or = $25,000 per year (39% vs 69%, p < 0.001), and were married less often at the time of surgery (59% vs 85%, p < 0.001). Fewer women than men were able to perform basic self-care activities (p < 0.001) and social activities (p < 0.001). Women were also less able to perform the more demanding activities required for independent living, recreation, and maintaining a household (p < 0.001). Women were also more anxious (p = 0.01) and reported more depressive symptoms (p < 0.001) than men. These data suggest that plans for perioperative and convalescent care for women undergoing CABG should take into account their less favorable medical and psychosocial status relative to men.

A caffeine/ryanodine-sensitive Ca2+ pool is involved in triggering spontaneous variations of Ca2+ in Jurkat T lymphocytes by a Ca(2+)-induced Ca2+ release (CICR) mechanism

Caffeine and ryanodine triggered an increase in [Ca2+]i (73 +/- 22 and 61 +/- 18 nM, respectively) in Jurkat cell populations that was independent of external Ca2+. In individual cells, caffeine and ryanodine induced Ca2+ spikes. Jurkat cell populations initially exposed to caffeine did not respond further to ryanodine and vice versa, suggesting an overlap of the Ca2+ pool that was contained within the thapsigargin-sensitive Ca2+ reserve. [3H]ryanodine bound to a single class of sites of Jurkat microsomes (KD, 18.4 +/- 5.7 nM; Bmax, 24.3 +/- 7.7 fmol/mg protein). Photolytic release (Nitr5) of caged Ca2+ induced a time-dependent increase of Ca2+ in individual Jurkat cells. The profile of the release of Ca2+ was characterized, 1) by a kinetic (0.55 +/- 0.07 nM s-1) slower than the Ca2+ response to caffeine (3.93 +/- 0.66 nM s-1) or to ryanodine (3.96 +/- 0.94 nM s-1), 2) by a release of Ca2+ (131 +/- 43 nM) that slowly returned to baseline and during which low amplitude oscillations were present (room temperature) or Ca2+ spikes (37 degrees C) and, 3) by a lack of dependency on an influx of Ca2+. Inhibitors of CICR (ruthenium red and 1-octanol) prevented the photolysis-dependent increase in [Ca2+]i but not the InsP3-dependent Ca2+ response. Our data suggest that Jurkat T cells possess at least two Ca2+ pools, one that is sensitive to InsP3 and one that is insensitive. These two Ca2+ pools may be involved in a CICR that generates spontaneous Ca2+ spikes and oscillations in these cells.

Panic disorder in emergency department chest pain patients: prevalence, comorbidity, suicidal ideation, and physician recognition

PURPOSE

To establish the prevalence of panic disorder in emergency department (ED) chest pain patients; compare psychological distress and recent suicidal ideation in panic and non-panic disorder patients; assess psychiatric and cardiac comorbidity; and examine physician recognition of this disorder.

DESIGN

Cross-sectional survey (for psychiatric data). Prospective evaluation of patient discharge diagnoses and physician recognition of panic disorder.

SETTING

The ambulatory ED of a major teaching hospital specializing in cardiac care located in Montreal, Canada.

SUBJECTS

Four hundred and forty-one consenting, consecutive patients consulting the ED with a chief complaint of chest pain.

PRIMARY OUTCOME MEASURE

Psychiatric diagnoses (AXIS I). Psychological and pain test scores, discharge diagnoses, and cardiac history.

RESULTS

Approximately 25% (108/441) of chest pain patients met DSM-III-R criteria for panic disorder. Panic disorder patients displayed significantly higher panic-agoraphobia, anxiety, depression, and pain scores than non-panic disorder patients (P < 0.01). Twenty-five percent of panic disorder patients had thoughts of killing themselves in the week preceding their ED visit compared with 5% of the patients without this disorder (P = 0.0001) even when controlling for co-existing major depression. Fifty-seven percent (62/108) panic disorder patients also met criteria for one or more current AXIS I disorder. Although 44% (47/108) of the panic disorder patients had a prior documented history of coronary artery disease (CAD), 80% had atypical or nonanginal chest pain and 75% were discharged with a "noncardiac pain" diagnosis. Ninety-eight percent of the panic patients were not recognized by attending ED cardiologists.

CONCLUSIONS

Panic disorder is a significantly distressful condition highly prevalent in ED chest pain patients that is rarely recognized by physicians. Nonrecognition may lead to mismanagement of a significant group of distressed patients with or without coronary artery disease.

Effects of staurosporine on the capacitative regulation of the state of the Ca2+ reserves in activated Jurkat T lymphocytes

Staurosporine (Stp) is an inhibitor of protein kinase C (PKC) that has been used to address the role of this enzyme in a variety of cells. However, Stp can also inhibit protein tyrosine kinases (PTK). We have investigated the effects of Stp on the InsP3-(using mAb C305 directed against the beta chain of the T cell receptor (TcR/CD3 complex) and the thapsigargin (Tg)-dependent release and influx of Ca2+ in human (Jurkat) T cells. The addition of Stp (200 nM) during the sustained phase of the TcR-dependent Ca2+ response resulted in a rapid inhibition of the influx of Ca2+ that was not seen when Ca2+ mobilization was triggered by Tg (1 microM). When the cells were preincubated with Stp (200 nM), there was an inhibition of the mAb C305- but not the Tg-dependent Ca2+ response. The effect of Stp was not the result of the inhibition of PKC as shown by down-regulation of PKC and with the use of the specific PKC inhibitor bis-indolyl maleimide GF 109203X. The effect of Stp on the entry of Ca2+ in activated (mAb C305) Jurkat lymphocytes was dose-related and was not the result of a direct inhibition of plasma membrane Ca2+ channels based on an absence of effect on the Tg-dependent entry of Ca2+ and the use of Ca2+ channel blockers (econazole and Ni2+). These blockers terminated the influx of Ca2+ but the Tg-sensitive Ca2+ reserves were not refilled in marked contrast to the effect of Stp. Quantification of InsP3 revealed that the addition of Stp resulted in an approximate 40% reduction in mAb C305-activated Jurkat cells. The effects of Stp can be explained as follows. Stp decreases the mAb C305-induced production of InsP3 by inhibiting the TcR/CD3-dependent activation of PTK associated with the stimulation of phospholipase C-gamma 1. A decrease in [InsP3] without a return to baseline is sufficient to close the InsP3 Ca2+ channel, endoplasmic Ca2+ ATPases use the incoming Ca2+ to refill the Ca2+ pools and that terminates the capacitative entry of Ca2+. A simple kinetic model reproduced the experimental data.

Cellular distribution of protein kinase C isozymes in CD3-mediated stimulation of human T lymphocytes with aging

Protein kinase C (PKC) is involved in a variety of cellular responses, such as the expression and secretion of IL-2, the regulation of cytotoxic killing and cell proliferation. It is known that these immune functions are altered with aging. Here, we show that anti-CD3-triggered T cell proliferation is significantly decreased with aging and that H7, an inhibitor of PKC, impairs the anti-CD3-induced T cell proliferation in a differential manner, lymphocytes of healthy young subjects being more sensitive to the PKC inhibitor than those of elderly subjects. We examined (Western blot) the presence and the cellular distribution of PKC isozymes in T lymphocytes of healthy young and elderly subjects in the resting state and after anti-CD3 mAb stimulation using antibodies directed against PKC alpha, beta, delta, epsilon and zeta isoforms in the cytosol and the plasma membrane fractions. These five PKC isotypes were present in human T cells of young and elderly subjects. However, their distribution between the cytosolic and membrane fractions varied according to the isozymes and the age of the subjects. In resting lymphocytes of young subjects, all the PKC isozymes were found in the cytosolic fraction, except PKC-zeta. In resting lymphocytes of elderly subjects PKC-zeta and -epsilon were almost equally distributed between the cytosolic and the membrane fractions, whereas PKC-alpha and -zeta were mainly found in the membrane fraction and PKC-beta was almost exclusively located in the cytosolic fraction. The translocation of PKC-alpha, -beta, -delta and -epsilon could be observed under anti-CD3 mAb stimulation in lymphocytes of young subjects, while in the case of elderly subjects only the PKC beta isoform was translocated. Our results suggest tha the decreased availability of cytosolic PKC may contribute to the diminished PKC-dependent responses to CD3-triggered stimulation of human T lymphocytes with aging.

[Nodular or pseudo-nodular Hashimoto thyroiditis. Value of cytologic examination]

OBJECTIVES

Nodular or pseudo-nodular aspects of Hashimoto's thyroiditis raise the problem of the association with a differentiated carcinoma or a non Hodgkin's lymphoma.

METHODS

We looked for patients needing surgery in 165 cases of Hashimoto's thyroiditis. For this purpose, we used fine needle aspiration cytology.

RESULTS

We found a differentiated carcinoma in 4% of cases and a non Hodgkin's lymphoma in 1% of cases.

CONCLUSION

In nodular or pseudo-nodular aspects of Hashimoto's thyroiditis, fine needle aspiration cytology is helpful for the nodule diagnosis and for the selection of suspicious nodules only to be referred to surgery.

Panic disorder, chest pain and coronary artery disease: literature review

OBJECTIVE

To examine the association among panic disorder, atypical chest pain and coronary artery disease (CAD). This article's purpose is to inform cardiologists of the prevalence of psychiatric disorders, primarily panic disorder, among patients consulting for chest pain. Panic disorder is described. Treatment modalities are summarized, and social, financial and medical consequences of nondetection are underlined.

DATA SOURCES

PSYCHLIT and MEDLINE searches under panic disorder and chest pain-related headings were conducted.

DATA EXTRACTION

The search covered January 1973 to June 1993. Thirty-eight articles were studied.

DATA SYNTHESIS

Panic disorder is present in 30% or more of chest pain patients with no or minimal CAD and may coexist with CAD. Panic disorder may often be unrecognized by physicians. Left untreated, risk for disease progression may be augmented, and social vocational disability as well as medical costs may increase.

CONCLUSION

Physicians should attend to the panic symptomatology and, when in doubt, refer possible panic patients with or without CAD to a mental health professional for assessment and treatment. Future panic prevalence studies in cardiology patients should be prospective, attempt to increase sample size and use randomized protocols where experimenters are blind to chest pain and medical diagnoses. Studies should also focus on CAD patients with atypical chest pain refractory to optimal cardiac therapy.

Porous balloon catheters for local delivery: assessment of vascular damage in a rabbit iliac angioplasty model

OBJECTIVES

This experimental study assessed long-term vascular damage induced by the use of porous balloon catheters designed for local delivery.

BACKGROUND

Local drug delivery using porous balloon catheters has emerged as a possible means by which compounds designed to prevent restenosis might be delivered locally at concentrations higher than achievable by systemic administration. There are, nonetheless, some concerns about the possibility of greater arterial trauma induced by the high pressure fluid jets from the delivery catheter itself, a complication that could provide additional stimulus for intimal hyperplasia. Because these concerns are based mainly on in vitro studies and on studies performed after acute experiments, further work is required to assess the long-term effects of this device on the arterial wall.

METHODS

Local delivery of a saline solution was performed in 32 rabbits in one iliac artery, using an inflation pressure of 6 atm and a balloon/artery ratio of 1.3 to 1.5, followed by angioplasty in both iliac arteries. Vascular injury was assessed using tritiated thymidine incorporation at 4 days (12 rabbits) and planimetry at 30 days after the procedure (20 rabbits).

RESULTS

Tritiated thymidine incorporation did not reveal any significant difference between the angioplasty group and the group with local delivery and angioplasty (117,921 +/- 18,853 vs. 140,652 +/- 23,125 cpm/mg protein, p = NS). Planimetry at 30 days was also similar in the two groups (neointimal area 0.11 +/- 0.02 vs. 0.13 +/- 0.02 mm2).

CONCLUSIONS

In this model the use of porous balloon catheters before angioplasty did not lead to greater intimal hyperplasia than angioplasty alone. Further experimental investigation is required to determine whether this strategy could be used to prevent postangioplasty restenosis in humans.

[Diabetes and road safety]

The purpose of this study is to analyse the driving habits of a group of diabetic individuals, insulin and noninsulin treated, compared with the driving habits of an equivalent group of individuals in good health. Specific attention is given to the evaluation and management of stress related to driving. The analysis relies mainly upon the answers of 307 persons of both sex on a questionnaire regarding their driving habits and concerning twenty more or less risky behaviors. The diabetic subjects were sampled among the patients of an endocrinology clinic, and the pilot group (in good health) was gathered among the patients from the clinic of a general practitioner. The subjects were aged between 25 and 65. All were in possession of a driving licence and had a driving experience of over two years. The results show, on one hand, that the evaluation of stress related to a risky behavior is associated to the taking of risk at the wheel, and on the other hand, that compared with the other subjects in the study the diabetic subjects had a lesser tendency to taking risks in driving. The subjects avoided the behaviors they judged risky. Beside avoiding dangerous road behaviors, the latter brought special attention to food and relaxation needs and they showed a great alertness towards climatic and road conditions. Finally, they are especially careful in preventing and curing hypoglycaemic states.

A new approach for quality of life assessment in cardiac patients: rationale and validation of the Quality of Life Systemic Inventory

OBJECTIVE

To validate an interview-like questionnaire measuring quality of life, based on the subject's capacity to reach personal goals in different life domains.

DESIGN

One group repeated measures for test-retest reliability (two-week interval) and correlational approach for concurrent validity.

PARTICIPANTS

A total of 171 normal subjects (95 males and 76 females) was interviewed. Mean age was 43.6 years.

OUTCOME MEASURES

The Quality of Life Systemic Inventory (QLSI), the Beck Depression Inventory, the State-Trait Anxiety Inventory, the Marlowe and Crowne Social Desirability Scale, the Buss and Durkee Hostility Inventory, the Carver and Sheerer self-efficacy scale and the Derogatis Stress Profile were used.

RESULTS

The quality of life score (a gap score representing the difference between a subject's actual state and personal goal) has a high test-retest reliability of 0.838. The two other scores (goal and potential for conflict) also have good test-retest reliability: 0.858 for both. Intercorrelations between scores are low-gap-goal, 0.293; gap-conflict, 0.172; and goal-conflict, 0.115--suggesting their distinctiveness. Correlations between scores and social desirability are also low-gap, 0.106; conflict, -0.024; and goal, -0.128. Finally, correlations with other psychological variables such as depression, anxiety, self-efficacy and stress are moderate to low, showing that the questionnaire measures dimensions different from these variables.

CONCLUSIONS

The QLSI has good test-retest reliability, and scores are not much influenced by social desirability despite the fact that the test is used in an interview setting. The questionnaire may be administered in small groups or face-to-face situations. It yields a wealth of clinical information and is easily used in research. Furthermore, patients much prefer this interactive exchange to the long self-administered questionnaires.

Priming of human monocytes with leukotriene B4 enhances their sensitivity in IL-2-driven tumor necrosis factor-alpha production. Transcriptional and post-transcriptional up-regulation of IL-2 receptors

Cytotoxic activity of monocytes may be mediated by their production of TNF-alpha, and IL-2 has been shown to induce TNF-alpha production in monocytes and alveolar macrophages. Unstimulated human monocytes constitutively express the beta-chain of the IL-2R (IL-2R beta), but little or no IL-2R alpha. When monocytes were pretreated with leukotriene (LT) B4, they responded to IL-2 with both enhanced production of TNF-alpha (two- to threefold) and, more strikingly, with augmented sensitivity (1000-fold) to IL-2. Treatment of monocytes with LTB4 induced IL-2R alpha gene transcription at 30 min and augmented expression of IL-2R alpha gene transcripts by 3 h, maximal at 10(-8) M LTB4. LTB4 induced increased shedding of the IL-2R alpha in the culture supernatants and a modest induction of IL-2R alpha protein expression on monocytes. On the other hand, although LTB4 could stimulate the cell membrane expression of IL-2R beta and the accumulation of IL-2R beta mRNA, LTB4 did not significantly affect IL-2R beta gene transcription. The augmented expression of IL-2R on monocytes was associated with augmented binding of 125I-labeled IL-2 to LTB4-pretreated monocytes. Our data present direct evidence that the inflammatory lipid mediator LTB4 can induce the expression of IL-2R alpha in human monocytes by activating IL-2R alpha gene transcription; it can also stimulate the expression of IL-2R beta, through post-transcriptional regulation; this augmented expression of both alpha- and beta-chains of the IL-2R is associated with enhanced sensitivity of monocytes to IL-2 in terms of TNF-alpha production and may be relevant to the proinflammatory actions of LTB4.

Priming of human monocytes with leukotriene B4 enhances their sensitivity in IL-2-driven tumor necrosis factor-alpha production. Transcriptional and post-transcriptional up-regulation of IL-2 receptors

Cytotoxic activity of monocytes may be mediated by their production of TNF-alpha, and IL-2 has been shown to induce TNF-alpha production in monocytes and alveolar macrophages. Unstimulated human monocytes constitutively express the beta-chain of the IL-2R (IL-2R beta), but little or no IL-2R alpha. When monocytes were pretreated with leukotriene (LT) B4, they responded to IL-2 with both enhanced production of TNF-alpha (two- to threefold) and, more strikingly, with augmented sensitivity (1000-fold) to IL-2. Treatment of monocytes with LTB4 induced IL-2R alpha gene transcription at 30 min and augmented expression of IL-2R alpha gene transcripts by 3 h, maximal at 10(-8) M LTB4. LTB4 induced increased shedding of the IL-2R alpha in the culture supernatants and a modest induction of IL-2R alpha protein expression on monocytes. On the other hand, although LTB4 could stimulate the cell membrane expression of IL-2R beta and the accumulation of IL-2R beta mRNA, LTB4 did not significantly affect IL-2R beta gene transcription. The augmented expression of IL-2R on monocytes was associated with augmented binding of 125I-labeled IL-2 to LTB4-pretreated monocytes. Our data present direct evidence that the inflammatory lipid mediator LTB4 can induce the expression of IL-2R alpha in human monocytes by activating IL-2R alpha gene transcription; it can also stimulate the expression of IL-2R beta, through post-transcriptional regulation; this augmented expression of both alpha- and beta-chains of the IL-2R is associated with enhanced sensitivity of monocytes to IL-2 in terms of TNF-alpha production and may be relevant to the proinflammatory actions of LTB4.

Microtubules are not an essential component of phytohemagglutinin-dependent signal transduction in Jurkat T lymphocytes

We have used two disruptors of the cytoskeleton microtubular network (colchicine and vinblastine) to investigate the role of microtubules in Phaseolus vulgaris phytohemagglutinin (PHA) signal transduction in Jurkat T cells. Both drugs decreased but did not abolish the PHA-dependent Ca2+ response of Jurkat cells. Neither colchicine nor vinblastine had any major effects on the PHA-dependent turnover of the mono-, di-, tri-, and tetra-substituted phosphorylated derivatives of D-myo-inositol or the cellular distribution of protein kinase C (PKC) activity. However, both microtubule disruptors increased interleukin-2 (IL-2) production. Whereas vinblastine enhanced IL-2 production approximately twofold at all the concentrations tested (0.1, 1.0, and 10 microM), colchicine did so only at a 10 microM concentration. When a combination of PHA and 12-O-tetradecanoyl-13-O-acetyl phorbol (TPA) was used, a small increase in IL-2 production was observed only in the presence of vinblastine (10 microM). In contrast to recent reports that microfilaments may be involved in the regulation of signal transduction, our data suggest that this is not the case for microtubules in PHA-dependent signal transduction in Jurkat T cells.

Effects of modulators of cytosolic Ca2+ on phytohemagglutin-dependent Ca2+ response and interleukin-2 production in Jurkat cells

We have previously reported the presence, in Jurkat T cells, of outward K+ currents and inward currents that have been attributed to Ca2+ channels. Here, we have studied the effects of dimethyl 1,4-dihydro-2,6-dimethyl-4-(2-nitrophenyl)-3,5-pyridine-dicarboxylate (nifedipine) and 4-(2,1,3-benzoxadiazol-4-yl)-1,4-dihydro-2,6-dimethyl-5- methoxy-carbonylpyridine-3-carboxylate (PN200-110), two dihydropyridines (DHPs) known to inhibit voltage-dependent Ca2+ channel activity in different types of cells, and two inhibitors of internal Ca2+ release (muscle cells), ryanodine and 3,4,5-trimethoxybenzoic acid 8-(diethylamino)octyl ester (TMB-8), on the Phaseolus vulgaris phytohemagglutinin (PHA)-dependent responses in Jurkat T lymphocytes. Our results show that nifedipine and PN200-110 inhibit the PHA-dependent production of interleukin-2 except when 12-O-tetradecanoyl-13-O-acetyl phorbol is added to the cultures. Ryanodine and TMB-8 are not inhibitors. The PHA-dependent Ca2+ response is significantly reduced when the cells are preincubated in the presence of the DHPs. Under these conditions, ryanodine has only a small inhibitory effect and TMB-8 has no effect. In contrast, only ryanodine (50 microM) decreases the PHA-dependent cytosolic release of Ca2+i when the cells are bathed in a medium containing a low concentration of Ca2+ (60 nM). The inhibitory effects of nifedipine and PN200-110 may result from the binding of these DHPs to specific receptor sites as revealed by studies using [3H]PN200-110 (KD = 8.5 +/- 3.1 nM; 2300 +/- 500 apparent binding sites/cell). Photoaffinity labeling studies using [3H]azidopine as a probe showed specific incorporation of label into three glycoproteins of molecular mass (+/- SD) 170 +/- 13, 110 +/- 25, and 60 +/- 17 kd as analyzed by electrophoresis under reducing conditions.

Q fever endocarditis: diagnostic approaches and monitoring of therapeutic effects

The scope of current diagnostic methods for Q fever endocarditis includes serology, direct demonstration of Coxiella burnetii in the resected heart valve tissue, and animal inoculation studies. Illustrated by a clinical case report, the different methods are presented and discussed. Serology represents the primary method, using the techniques of complement fixation, indirect immunofluorescence, and enzyme-linked immunosorbent assay (ELISA). The latter two techniques allow the detection of immunoglobulins G, M, and A to the phase I and II antigens of C. burnetii. After cardiac surgery, we visualized C. burnetii on smears and specifically stained it on histologic sections of the resected heart valve by light and electron microscopic immunohistochemistry. In addition, seroconversion in animals after inoculation with valve specimens confirmed the presence of C. burnetii in the heart valve. The antibody titers determined by ELISA correlated well with the patient's clinical course during the treatment period. Therefore it is suggested that its usefulness for monitoring the efficacy of antimicrobial agents in patients with Q fever endocarditis should be further evaluated.

Dual regulation of the n type K+ channel in Jurkat T lymphocytes by protein kinases A and C

We have measured the activity of the n type K+ channel present in human (Jurkat) T lymphocytes using the patch clamp technique in the whole-cell configuration. We report that protein kinase A (PKA) and protein kinase C (PKC) modulate, in a dual manner, the K+ conductance in these cells. Activation of PKA decreases the amplitude of the current, as previously reported (Bastin, B., Payet, M. D., and Dupuis, G. (1990) Cell. Immunol. 128, 385-399), and this is also the case for 12-O-tetradecanoylphorbol-13-acetate-dependent activation of PKC. In contrast, inhibitors of PKC (H7, staurosporine, polymixin B, and anti-PKC antibody) increase the current amplitude. Of importance, down-regulation of PKC or its inhibition prevented the PKA-dependent inhibition of the K+ channels. Addition of alkaline phosphatase via the patch pipette increased the K+ conductance under basal conditions and reversed the inhibition produced by PKA. The dual modulation of K+ channels in Jurkat T cells is in agreement with the presence of consensus sequences in the primary structure of the n type K+ channel.

Human PAF receptor gene expression: induction during HL-60 cell differentiation

Platelet-activating factor is a potent lipid mediator of inflammation and immune regulation. Its numerous biological activities are mediated through specific receptors on the plasma membranes of responsive cells. The expression of such receptors may be modulated by various agents, including those responsible for cell differentiation. Here, we demonstrate that differentiation of the human promyelocytic leukemia cell line HL-60 by 1 alpha,25(OH)2 vitamin D3 towards the macrophage phenotype is associated with induction of PAF receptor gene expression: PAF receptor mRNA accumulation correlates with the induction and development of specific PAF responsiveness as assayed by [Ca2+]i fluxes. Our studies suggest that PAF responsiveness parallels macrophage differentiation and that PAF receptor expression can be regulated at the transcriptional level.

Evaluation of the nutritive value of grass hays for growing sheep

Data collected during 2 years on four grasses (three cultivars of timothy and one cultivar of bromegrass) harvested at four stages of growth were analyzed to identify variables that affect the nutritive value of grass hays for sheep. From 11 June, the day of the first harvest, to July 25, the percentage of crude protein (CP) decreased 0.17 unit/d (r2 = 0.86, P < 0.001) and the percentage of acid detergent lignin (ADL) increased 0.06 units/d (r2 = 0.74, P < 0.001). Over this period, dry matter (DM) intake decreased at a rate of 0.41 g kg−0.75 d−1 (r2 = 0.54, P < 0.001) and was negatively correlated with fiber content (P < 0.001). Delay of harvest caused a decrease in percent digestibility of 0.39 unit/d for DM (r2 = 0.86, P < 0.001), 0.38 unit/d for energy (r2 = 0.85, P < 0.001), 0.54 unit/d for CP (r2 = 0.77, P < 0.001) and 0.63 unit/d for NDF (r2 = 0.93, P < 0.001). Total digestible nutrients (TDN) decreased 0.35 unit/d (r2 = 0.86, P < 0.001). Date of harvest and %ADL were used to estimate energy value of hays. Digestible energy intake and TDN intake values decreased by 122.4 kJ kg−0.75 (r2 = 0.87, P < 0.001) and 6.6 g kg−0.75 (r2 = 0.89, P < 0.001), respectively, for each 1% increase in ADL of the hays. Equations were developed to estimate digestible DM intake and TDN intake, using NDF and ADF as independent variables. The predictive value of the equations was good when applied to data obtained from previous experiments (r2 = 0.87–0.91, n = 11, P < 0.001). Key words: Nutritive value, forages, sheep

Predictive model to determine cost/benefit of early detection and intervention in occupational low back pain

Low back pain related to work injury has major socioeconomic implications. Theoretically, the early detection of patients at risk for continued work disability after 6 months of work absence, and of those with a recurrence of pain (RP) and leave work once again, should be cost-effective if combined with effective intervention. The objective of this prospective research was to analyze the cost-effectiveness of a detection-intervention system (DIS) developed from a logistic predictive model of work status. A sample of newly injured workers (N=135 males) were assessed following a first episode of compensated low back pain. A predictive biopsychosocial profile was obtained from a series of univariate and multivariate regression analyses. Structural diagnosis, pain rating, length of inactivity before treatment, negative life changes, and self-efficacy expectancies were found to be best predictors. With a correct classification rate of 72% the predictive model parameters (sensitivity and specificity) were chosen in order to reduce the number of false negatives (recurrence of pain or chronic patients not detected). The calculation of the cost/benefit proportions reveals that the detection-intervention system generates savings of up to $39,595 Can./100 patients a year. By combining low treatment expenses ($250 Can to $1,000 Can.) and increasing the success rates (40-75% return to work), the detection-intervention system is potentially more cost effective than the current approach without detection-intervention.

Spectrofluorimetric and image recordings of spontaneous and lectin-induced cytosolic calcium oscillations in Jurkat T cells

Intracellular variations in Ca2+ concentrations have been measured in single Jurkat T lymphocyte variants (77 6.8 and E6.1) using Fura-2 as a probe. Under basal conditions, the cytosolic Ca2+ level is stable but some cells show spontaneous Ca2+ oscillations (frequency, 0.30 +/- 0.06 Hz). These oscillations are sensitive to the external concentration of Ca2+ since they can no longer be observed when the bathing solution is replaced (superfusion) with a Ca(2+)-free medium or when a Ca2+ chelator (EGTA) is added. Various changes in the cytosolic concentration of Ca2+ ([Ca2+]i) can be observed when the cells are exposed to the mitogenic lectin phytohemagglutinin (PHA, 80 nM). For instance, in the case of non-oscillating cells, the lectin induces either a rapid increase in [Ca2+]i that is followed by a sustained response (plateau) or it triggers Ca2+ spikes. In the case of experiments done in Ca(2+)-free medium, only the initial spike was observed. In the case of spontaneously oscillating cells, PHA induces a rapid increase in [Ca2+]i that is followed by a plateau where oscillations are absent. In every case, the PHA-dependent Ca2+ response is abrogated in a Ca(2+)-free medium. Computer simulations based on the model of Goldbeter et al. [27] show that the various Ca2+ responses of Jurkat cells are related to the cytosolic level of free Ca2+. Video imaging analyses show that the cellular Ca2+ responses are not homogeneous whether the observations are made in spontaneously oscillating Jurkat cells or when they are exposed to PHA.

[The diagnosis of Lyme borreliosis. Apropos of a neurological case]

The clinical diagnosis of Lyme borreliosis is easily established in the initial phase of the illness. Erythema chronicum migrans is pathognomonic of this infection. However, during further complications (neurological, cardiac or articular) the diagnosis is chiefly based on laboratory results. The detection of specific antibodies to B. burgdorferi is one of the effective means of confirming the diagnosis. Culture or isolation of this bacteria is not routinely performed due to its very low yield. In this article a case of serologically proved neuro-borreliosis is described and the methods of diagnosis are discussed. Intrathecal synthesis of antibodies observed in the cerebrospinal fluid of this patient and the specificity of serologic tests confirmed by Western-blot provide the diagnosis. However, the absence of locally synthesized antibodies in the cerebrospinal fluid is not sufficient to rule out neuro-borreliosis.

Effects of modulators of adenylyl cyclase on interleukin-2 production, cytosolic Ca2+ elevation, and K+ channel activity in Jurkat T cells

We have studied the effects of prostaglandin E2 (PGE2) and cholera toxin, two modulators of adenylyl cyclase, and 8-bromo cAMP (8-BrcAMP) on various parameters of lymphocyte activation using the human T cell line Jurkat. Our results show that PGE2 and cholera toxin inhibit, in a dose-related manner, the phytohemagglutinin (PHA)-dependent production of interleukin 2 by these cells. The data are consistent with the interpretation that the inhibition is due to an intracellular increase in cAMP, since the metabolically stable 8-BrcAMP analog produced the same inhibitory effect. However, PGE2 or 8-BrcAMP did not interfere with the PHA-induced elevation in the cytosolic concentration of Ca2+, suggesting that changes in the intracellular concentration of cAMP does not affect the internal release or the influx of Ca2+. In contrast, cholera toxin prevented the Ca2+ response of Jurkat cells to PHA. We studied the effects of PGE2, cholera toxin, and 8-BrcAMP on the amplitude of the K+ outward current using the patch clamp technique in the whole cell configuration. Results showed that PGE2, 8-BrcAMP, and cholera toxin inhibited K+ channel activity. For instance, the amplitude of the outward K+ current was reduced to 43 +/- 19%, 50 +/- 26%, and 46 +/- 16% of control values in the case of cells perfused in the presence of PGE2, 8-BrcAMP, and cholera toxin, respectively. Blocking K+ channels with tetraethylammonium ions did not prevent the characteristic Jurkat Ca2+ response to PHA. Our observations that cAMP inhibits K+ channel activity in a T cell line provide an additional explanation for its reported inhibition of lymphocyte activation. Increasing the intracellular concentration of cAMP may result in reduction of K+ movements and in negative modulation of signal transduction via G-proteins as previously suggested. These two effects could act in synergy to impair signal transduction.