Gamma interferon and lymphotoxin, released by activated T cells, synergize to inhibit granulocyte/monocyte colony formation.

We have shown that lymphocytes stimulated by PHA produce colony-forming unit of granulocyte/monocyte (CFU-GM)-stimulating and -inhibiting activities, IFN-gamma, and lymphotoxin (LT). IFN-gamma is necessary for inhibition of CFU-GM by PHA-conditioned medium (CM), as shown by experiments in which removal of IFN-gamma from PHA-CM abrogated inhibition. However, experiments in which rIFN-gamma was added to IFN-gamma-depleted PHA-CM revealed the presence, in PHA-CM, of other factors that act in synergy with IFN-gamma to inhibit CFU-GM. Fractionation of PHA-CM on a Sephadex G-100 column was used to separate IFN-gamma and LT. Colony-inhibiting activity was eluted in fractions that contained both IFN-gamma and LT activities, identifying LT as a factor present in PHA-CM that synergizes with IFN-gamma to inhibit CFU-GM. Treatment of PHA-CM with mAb against either IFN-gamma or LT completely abrogated the colony-inhibiting activity, demonstrating a requirement for both lymphokines in PHA-CM-induced inhibition of CFU-GM. Experiments using rIFN-gamma and preparations of purified LT confirmed that neither lymphokine alone, when added to bone marrow cells at the concentrations present in PHA-CM, strongly inhibited day 7 or day 14 CFU-GM, but that the two lymphokines, added together, behaved synergistically to inhibit CFU-GM by up to 70%. The inhibition observed using purified preparations of lymphokines shows that synergy between IFN-gamma and LT is sufficient to explain PHA-CM-induced inhibition of CFU-GM. Our findings suggest that activated T cells regulate hematopoiesis through the release of inhibitory as well as stimulatory factors, and that the simultaneous production of IFN-gamma and LT may represent a mechanism of suppression of hematopoiesis in the cases of bone marrow failure associated with the presence of activated T cells.

Tumor necrosis factor and lymphotoxin induce differentiation of human myeloid cell lines in synergy with immune interferon.

We show that the cytotoxins tumor necrosis factor (TNF) or lymphotoxin (LT), at concentrations of approximately 10(-11) M induce monocytic differentiation of human myeloid cell lines. After 5 d of culture in the presence of rTNF and LT, a significant proportion of the myeloid cell lines express monocyte differentiation antigens and ANAE activity, and become able to reduce nitroblue tetrazolium (NBT) and mediate low levels of ADCC against tumor target cells. These markers of differentiation, however, are maximally induced when rIFN-gamma, at concentrations as low as 4 U/ml, is present simultaneously with the cytotoxins, and the two classes of cytokines act synergistically to induce terminal differentiation. The appearance of monocytic antigens is accompanied by acquisition of morphology and other functional properties of mature monocytic cells, such as chemiluminescence and phagocytosis, and by expression of FcR for monomeric IgG. A decrease in cell proliferation accompanies induced differentiation, and is not due to the cytotoxic properties of TNF or LT, as indicated in simultaneous analysis of surface phenotype and cell cycle. The lack of cytotoxicity of TNF on the HL-60 cell line is also demonstrated by the enhancing effect of TNF on HL-60 cell growth and nucleoside uptake in the first 2 d of culture. These data show that the cytotoxins TNF and LT mediate complex effects on cells of the myelomonocytic lineage and, in synergy with IFN-gamma, can fully induce immature myeloid cells to differentiate into cells with phenotypic, functional, and proliferative characteristics of terminally differentiated myelomonocytic cells.

Production of hematopoietic colony-stimulating factors by human natural killer cells.

We have analyzed the ability of highly purified preparations of human NK cells to produce CSF. NK cells, purified by negative selection from 10-d cultures of PBMC incubated with irradiated B-lymphoblastoid cell lines, were stimulated with rIL-2, FcR(CD16) ligands (particulate immune complexes or anti-CD16 antibodies bound to Sepharose), a combination of CD16 ligands and rIL-2, or the phorbol diester phorbol dibutyrate (PDBu) together with the Ca2+ ionophore A23187. Both rIL-2 and CD16 ligands induce accumulation of GM-CSF mRNA in NK cells and the combined effect of the two stimuli is synergistic. Maximal accumulation of GM-CSF mRNA is observed after PDBu/A23187 stimulation. The participation of contaminant T cells in the observed expression of the GM-CSF gene is excluded because CD16 ligands do not stimulate T cells and CD3 ligands, powerful stimulators of T cells, are inactive on NK cells. Accumulation of CSF-1 mRNA is observed only in NK cells stimulated with both CD16 ligands and rIL-2, whereas accumulation of IL-3 mRNA is observed only in NK cells stimulated with PDBu/A23187. Transcripts of the G-CSF, IL-1 alpha, and IL-1 beta genes were never detected in NK cells in these experiments. The kinetics of accumulation of GM-CSF and CSF-1 mRNA in NK cells stimulated with CD16 ligands and rIL-2 peaked at 2-4 h and was slower than that of TNF and IFN-gamma mRNA, which peak at 1 h. GM-CSF was precipitated from the supernatant fluids of NK cells stimulated with PDBu/A23187 and its biological activity was demonstrated by the ability of the supernatants to sustain proliferation of the TALL-101 cell line or CML blasts. Biological activity of IL-3 and CSF-1 was demonstrable in supernatant fluids of NK cells stimulated with PDBu/A23187 and CD16 ligands/rIL-2, respectively.

Identification and purification of natural killer cell stimulatory factor (NKSF), a cytokine with multiple biologic effects on human lymphocytes.

We have identified and purified a novel cytokine, NK cell stimulatory factor (NKSF), from the cell-free supernatant fluid of the phorbol diester-induced EBV-transformed human B lymphoblastoid cell line RPMI 8866. NKSF activity is mostly associated to a 70-kD anionic glycoprotein. The purified 70-kD protein, isolated from an SDS-PAGE gel, yields upon reduction two small species of molecular masses of 40 and 35 kD, suggesting that this cytokine is a heterodimer. When added to human PBL, purified NKSF preparations induce IFN-gamma production and synergize with rIL-2 in this activity, augment the NK cell-mediated cytotoxicity of PBL preparations against both NK-sensitive and NK-resistant target cell lines, and enhance the mitogenic response of T cells to mitogenic lectins and phorbol diesters. The three activities remain associated through different purification steps resulting in a 9,200-fold purification, and purified NKSF mediates the three biological activities at concentrations in the range of 0.1-10 pM. These data strongly suggest that the same molecule mediates these three activities, although the presence of traces of contaminant peptides even in the most purified NKSF preparations does not allow us to exclude the possibility that distinct biologically active molecules have been co-purified. The absence of other known cytokines in the purified NKSF preparations, the unusual molecular conformation of NKSF, the high specific activity of the purified protein, and the spectrum of biological activities distinguish NKSF from other previously described cytokines.

Metastatic pulmonary calcification in primary hyperparathyroidism.

Metastic pulmonary calcification (MPC) developed in a patient with primary hyperparathyroidism. Renal function was only minimally impaired (creatine clearance of 65 ml/min) the day prior to appearance of the lung infiltrate, but deteriorated (creatinine clearance of 14 ml/min) concomitantly with the appearance of MPC. Lung imaging with 99mTc bone-scanning agents helps differentiate MPC from other problems with similar clinical and roentgenographic findings, thus allowing prompt therapy.

Involvement of 5-hydroxytryptamine in the blood pressure changes evoked by electrical stimulation of the median raphe nucleus.

Electrical stimulation of the median raphe nucleus (MRN) in urethane-anaesthetised rats decreased systemic blood pressure at low intensities of stimulation (5-25 microA) and increased it with higher intensities (20-150 microA). Prazosin (0-5-5.0 micrograms/Kg i.v.) dose-dependently attenuated pressor responses concurrently with a reduction in the responsiveness of peripheral alpha-adrenoceptors to phenylephrine (500ng i.v.). Methiothepin (5-10 micrograms/Kg i.v.) abolished depressor responses and reduced the pressor effects without altering the response to phenylephrine. Ketanserin (5-10 micrograms/Kg i.v.) abolished depressor changes and potentiated pressor responses. High doses (20-200 micrograms/Kg) produced a decrease in pressor responses but correspondingly lowered BP and reduced the response to phenylephrine. The results suggest the presence of 5-HT-containing links between the MRN and the peripheral cardiovascular effector systems.

Quantitation of wheezing in acute asthma.

Pulmonary sounds were recorded before and after bronchodilator treatment in 20 patients with acute attacks of asthma. Analysis of the sounds showed that improvement in the forced expiratory volume in one second was associated with the following two changes in the sound signal: (1) the proportion of the respiratory cycle occupied by wheeze (Tw/Ttot ratio) was reduced from 86 percent to 31 percent on average; and (2) the sound frequency of the highest pitched wheeze was also reduced, from a mean of 440 Hz to 298 Hz.

Lung sound analysis for continuous evaluation of airflow obstruction in asthma.

We developed a system for monitoring airflow obstruction noninvasively, based on the principle that the proportion of the breath cycle occupied by wheezing (Tw/Ttot) in any one subject corresponds to the severity of airways obstruction. Lung sounds were recorded continuously from the chest wall. Fifty 250 ms sound segments were randomly chosen from five-minute periods and analyzed for the presence or absence of wheezes. The proportion with wheezes was used as an estimate of Tw/Ttot (Est Tw/Ttot). For 12 wheezy patients, there was a good correlation between the Est Tw/Ttot and the forced expiratory volume in one second (r = 0.893, p less than 0.001). The system was used to evaluate nocturnal asthma. Five subjects were studied over eight nights. It was found that there was more wheezing from 4:00 to 4:30 AM than from midnight to 12:30 AM (p less than 0.05). This technique may prove useful in continuous, noninvasive monitoring of wheezy patients.

The utility of a long-acting sympathomimetic agent, procaterol, for nocturnal asthma.

Patients with nocturnal asthma have their lowest pulmonary function and lowest serum epinephrine level at 4 to 6 AM. We studied a new long-acting beta-adrenergic agonist, procaterol, in ten patients with nocturnal asthma. The patients received 0.1 mg of procaterol one night and a placebo the other night in random order. Pulmonary function tests were performed every two hours from 10 PM to 8 AM. Pulmonary sounds were recorded using a modified stethoscope and were subsequently analyzed to estimate the proportion of time occupied by wheezing (est Tw/Ttot). The forced expiratory volume in one second (FEV1) while receiving the placebo and procaterol were similar at 10 PM (placebo, 1.35 +/- 0.18 L [mean +/- SE]; procaterol, 1.48 +/- 0.20 L); however, by 4 AM, the FEV1 had dropped significantly lower on the night with the placebo (1.01 +/- 0.14 L) than the night with procaterol (1.30 +/- 0.19 L; p less than 0.05). The est Tw/Ttot was similar at 12 AM for both nights, but at 4 AM, there was a significant increase in the est Tw/Ttot for the group with placebo but not the group with procaterol. The use of a long-acting beta-adrenergic sympathomimetic agent reversed the obstruction of the airways seen with nocturnal asthma.

Measuring crackles.

Crackles heard on auscultation can be represented graphically as a time-amplitude plot of the associated waveform. To assess the relative merits of several measures which might be considered for machine implementation in diagnostic instruments, we compared the reproducibility of those based on the initial voltage deflection which begins a crackle with those based on the largest deflection. The latter group showed less interobserver and less intraobserver variability when the same crackles were measured twice by each of two observers. Crackles from a teaching tape, categorized as fine and coarse, were used in this study. The ability of the various measures tested to distinguish between fine and coarse crackles on an individual basis was assessed and found to favor the measures based on the largest deflection. They showed an average of 9.96 percent incorrectly classified crackles, as opposed to 19.53 percent for the two measures based on the initial deflection.

Lung sound terminology in case reports.

Terms used to describe lung sounds in published case reports were tabulated, including qualifying adjectives. Seven journals were reviewed, and a total of 663 case reports were included. From the frequency of usage and similarity of qualifying adjectives it appears that "rales" and "crepitations" are equivalent terms. Many authors feel the need to qualify "rales": sixteen descriptive adjectives were encountered. Some authors distinguish between "rhonchus" and "wheeze," but the terms, for most, appear to mean the same thing. It is evident that current usage varies widely, even in the terminology of the basic categories of sounds.

Evaluation of dyspnea during physical and speech activities in patients with pulmonary diseases.

STUDY OBJECTIVES: Dyspnea is most commonly assessed by questioning patients about their subjective perception of shortness of breath during physical exertion. Although speech production is altered by pulmonary disease, it has not been included in current dyspnea assessment tools. A questionnaire was developed to address reports of dyspnea during (1) physical activity, (2) speech activity, and (3) simultaneous speech and physical activity. DESIGN: An equal number of self- and experimenter-administered 30-item questionnaires was given to 203 patients with restrictive and obstructive pulmonary diseases. Their responses were analyzed statistically. RESULTS: The questionnaire had high internal consistency for individual items within each of the three sections. The sections were highly correlated but provided separate and distinct information. Factors extracted from each section were related to severity of dyspnea. Pairwise t tests demonstrated highly significant differences in subject responses to the three sections. The least dyspnea was experienced during speech activities, more during physical activities, and the most when speech and physical activities were combined. CONCLUSIONS: The questionnaire proved to be a quickly administered tool for providing information about the effect of dyspnea on activities of daily living. Because of the emphasis on dyspnea during speech production, it may be particularly useful for assessing patients who rely extensively on speaking ability for their livelihood.

Bronchoscopy with bronchoalveolar lavage in tuberculosis and fungal infections.

STUDY OBJECTIVE: To determine the utility of bronchoscopy with bronchoalveolar lavage for diagnosing M tuberculosis and fungal infections. DESIGN: Retrospective review of patients over a six-year period. SETTING: In- and outpatients of one University hospital and affiliated Veterans Administration Medical Center. PATIENTS: Those who were subsequently found to have either M tuberculosis or fungal infections. INTERVENTIONS: Bronchoscopy with bronchoalveolar lavage specimens were compared to prebronchoscopy sputum, when available. Specimens were sent for smear and culture for both acid-fast bacilli and fungi. In the case of lavage, an aliquot also was studied for cellular differential. MEASUREMENTS AND RESULTS: For TB, sputum was smear-positive in 6/47 (34 percent) and culture positive in 24/47 (51 percent), while bronchoscopy was smear positive in 34/50 (68 percent) and culture positive in 46/50 (92 percent). For fungal infections, no sputum was smear-positive and only 1/22 (5 percent) was sputum culture-positive, while bronchoscopy was smear-positive in 14/41 (34 percent) and culture positive in 35/41 (85 percent). Bronchoscopy washings and BAL provided complementary specimens. Eighty-three patients had adequate lavages and the cellularity was significantly different from controls (lymphocytes: TB 18 +/- 11.2 percent [mean +/- SD]; fungal: 13 +/- 11.1 percent; controls 6 +/- 3.1 percent; p less than 0.001; neutrophils: TB 9 +/- 11.5 percent; fungal: 6 +/- 9.1 percent controls: 2 +/- 1.5 percent, p less than 0.01); however, there was overlap and no pattern was characteristic for TB or fungal infections. CONCLUSION: Bronchoscopy with BAL is useful in diagnosing tuberculosis and fungal infections.

Crackles in interstitial lung disease. Comparison of sarcoidosis and fibrosing alveolitis.

STUDY OBJECTIVE: Determine why crackles on chest auscultation are characteristic of most interstitial lung diseases, but may not be heard in sarcoidosis. DESIGN: All patients with sarcoidosis or cryptogenic fibrosing alveolitis seen during a four-week period were studied. In a second study to relate ausculatory findings to anatomy, patients with fibrotic changes on their chest roentgenogram were studied. SETTING: Patients were recruited from outpatient clinics. PATIENTS: In the first part, all patients seen over the course of one month were studied. In the second study, patients with pulmonary fibrosis seen on chest roentgenograms were studied. INTERVENTIONS: For the first study, two independent observers performed auscultation on five sites for crackles and reviewed four roentgenogram quadrants for changes. For the second study, patients underwent VC measurements, auscultation, and high resolution computer tomography scans. MEASUREMENTS AND RESULTS: For the first study, crackles were noted at greater than 2 sites in all 11 CFA patients, but only one of 17 SARC patients (p less than 0.001). Roentgenogram changes were seen in greater than 2 quadrants in nine of 11 CFA patients and eight of 17 SARC patients (p = ns). In the second study, the VC was similar in the two groups: SARC: 1.96 +/- .90 L (means +/- SD), 58 +/- 20.4 percent predicted; CFA: 1.81 +/- .33 L, 59 +/- 9.2 percent predicted). Only two of 14 SARC patients had crackles in greater than 1 area, while all 14 CFA patients had crackles at greater than 2 sites. The HRCT studies were read by a radiologist unaware of the diagnosis. The presence and degree (0 to 3 scale) of subpleural and peribronchial fibrosis were scored. Twelve SARC patients had peribronchial changes (mean score 1.9 +/- 1.08), while only eight had subpleural fibrosis (mean score .6 +/- .52). There was a significantly different pattern in the CFA patients, where eight had peribronchial fibrosis (mean score = .9 +/- .78, p less than 0.05) and all 14 had subpleural fibrosis (mean score = 1.6 +/- .73, p less than 0.01). CONCLUSIONS: We conclude that crackles are more frequent in fibrosing alveolitis than in sarcoidosis; this difference may be due to the distribution of parenchymal fibrosis.

Cerebrospinal fluid ions in metabolic acidosis in dogs: effects of acetazolamide.

We hypothesized that, during isosmotic isonatremic HCl acidosis with maintained isocapnia in cisternal cerebrospinal fluid (CSF), acetazolamide, by inhibiting carbonic anhydrase (CA) in the central nervous system (CNS), should produce an isonatric hyperchloric metabolic acidosis in CSF. Blood and CSF ions and acid-base variables were measured in two groups of anesthetized and paralyzed dogs with bilateral ligation of renal pedicles during 5 h of HCl acidosis (plasma [HCO3-] = 11 meq/l). Mechanical ventilation was regulated such that arterial PCO2 dropped and CSF Pco2 remained relatively constant. In group I (control group, n = 6), CSF [Na+] remained unchanged, [HCO3-] and strong ions difference (SID) fell, respectively, 6.1 and 5 meq/l, and [Cl-] rose 3.5 meq/l after 5 h of acidosis. In acetazolamide-treated animals, (group II, n = 7), CSF [Na+] remained unchanged, [HCO3-], and SID fell 11 and 7.1 meq/l, respectively, and [Cl-] rose 7.1 meq/l. We conclude that during HCl acidosis inhibition of CNS CA by acetazolamide induces an isonatric hyperchloric metabolic acidosis in CSF, which is more severe than that observed in controls.

Arrestins and G-protein--coupled receptors: an on-again, off-again relationship.

Arrestins are a family of regulatory proteins that uncouple activated seven-transmembrane domain receptors from G-proteins leading to termination of ligand-induced signaling. Our understanding of arrestins has been greatly enhanced in recent years through the identification of several new members of the arrestin family, clarification of the mechanisms by which these proteins turn off receptors, and elucidation of their role as adaptor molecules in receptor internalization.

Peptide LSARLAF activates alpha(IIb)beta3 on resting platelets and causes resting platelet aggregate formation without platelet shape change.

Adhesion of resting platelets to fibrinogen was enhanced by a peptide which was designed to bind near the presumptive fibrinogen gamma-chain binding site of the alpha subunit of the integrin alpha(IIb)beta3. This peptide, but not a scrambled control peptide, induced adhesion of resting platelets to fibronectin, vitronectin, von Willebrand factor, and monovalent (lacks one functional gamma-chain) fibrinogen. Resting platelets not treated with the agonist peptide did not adhere to these ligands. Agonist peptide induced adhesion of resting platelets to Fg was not secretion dependent and was inhibited by the monoclonal antibody 7E3. The agonist peptide caused aggregation of resting platelets on resting platelets adherent to immobilized Fg without causing platelet shape change. Therefore, the agonist peptide may activate alpha(IIb)beta3 by directly inducing a conformation change in the receptor on resting platelets.

The lung exam.

Accurate diagnosis is essential for effective treatment. After history-taking, the physical examination is second in importance in assessing a pulmonary patient. The time-honored sequence of inspection, palpation, percussion, and auscultation is appropriate. Diagnostic tests are becoming more complex, more expensive, and more inclined to separate the patient and physician. The stethoscope is still the more commonly used diagnostic medical instrument, but it is not always used to best advantage. It is familiar, harmless, portable, and inexpensive. Its appropriate use improves medical practice and reduces costs. Improvements in sound recording and analysis techniques have spurred a renewed interest in lung sounds and their meaning. This is likely to lead to better understanding of what we hear, and perhaps to the development of new noninvasive diagnostic and monitoring techniques.

Mechanisms of hyperventilation in head injury: case report and review.

We report the case of a head-injured patient with spontaneous hyperventilation who had recurrent episodes of relative hypoventilation associated with increases in intracranial pressure. Detailed ventilatory studies were performed during the 2nd week after injury. Our findings in this patient prompted us to review the possible mechanisms underlying the observed changes. We suggest that spontaneous hyperventilation in head injury is secondary to a decrease in cortical inhibitory influences on respiratory control mechanisms and that the transient episodes of relative hypoventilation observed in our patient may reflect modified ventilatory responses dependent on the altered state of consciousness. (Neurosurgery, 5: 701--707, 1979).

A novel method of guideline development for the diagnosis and management of mild to moderate hypertension.

BACKGROUND: There are large numbers of clinical guidelines available covering many clinical areas. However, the variable quality of their content has meant that doctors may have been offered advice that has been poorly researched or is of a conflicting nature. It has been shown that local involvement in guideline development increases the likelihood of their use. AIM: To develop a guideline to be used by general practitioners in six practices in Birmingham from existing evidence-based guidelines. METHOD: Recommendations from the four most cited international hypertension guidelines, and the more recently published New Zealand guidelines, were divided into subject areas and tabulated to facilitate direct comparison. Where there was complete or majority (> or = 3/5) agreement, the recommendation was taken as acceptable for inclusion in the new guideline. Where there was disagreement (< or = 2/5), recommendations were based on the best available evidence following a further MEDLINE literature search and critical appraisal of the relevant literature. Each recommendation was accompanied by a grade of evidence (A-D), as defined by the Canadian Hypertension Society, and an 'action required' statement of either 'must', 'should', or 'could', based on the Eli-Lilly National Clinical Audit Centre Hypertension Audit criteria. The recommendations were summarized into a guideline algorithm and a supporting document. The final format of both parts of the guideline was decided after consultation with the practice teams. The practices individually decided on methods of data collection. RESULTS: The guideline was presented as a double-sided, A4 laminated sheet and an A4 bound supporting document containing a synthesis of the original guidelines in tabular form, a table of the resulting recommendations, and appendices of current literature reviews on areas of disagreement. The content of the final Birmingham Clinical Effectiveness Group (BCEG) guideline differed minimally from any of the original guidelines. CONCLUSION: The main strength of this method of guideline development may lie, not in the actual content of the resulting guideline, but in the strength of ownership felt by the BCEG and the practices following its development. While the full process is unlikely to be possible for general practitioners working outside an academic environment, the techniques used could provide a framework for practitioners to adapt national and international guidelines for use at a local level.