Airway reactivity and exhaled NO following swine dust exposure in healthy volunteers.

Short-time exposure to swine dust causes an intense inflammation of upper and lower airways and induces increased bronchial responsiveness to methacholine in previously non-exposed healthy volunteers. The objective to this study was to investigate the nasal inflammatory response and mucosal reactivity to swine dust exposure and whether nitric oxide metabolism is involved in the inflammatory process. Nitric oxide in expired air, nasal histamine test (NH), nasal lavage (NAL) and bronchial histamine challenges were studied before and after a 3 h exposure to swine dust in a swine confinement building in 17 non-smoking healthy subjects not previously exposed to farm dust. To detect any interference between NAL and NH, the subjects were divided into two groups: in group 1, NAL was performed after NH and in group 2, NAL preceded NH. Nasal histamine response increased significantly in group 1, but not in group 2 (P=0.012). Albumin levels in NAL were higher before as well as after dust exposure in group 1 compared to group 2 (P=0.036 and 0.015 respectively). Bronchial histamine responsiveness increased following exposure (P= 0.045). Nitric oxide in expired air decreased following bronchial histamine challenge at baseline (P=0.013) but was otherwise unaltered. Short-time exposure to swine dust increases non-specific reactivity of both nose and bronchi. Nasal lavage procedure interferes with nasal histamine test when performed with connection to each other. The inflammatory reaction may involve NO metabolism.

Expression of nitric oxide synthases in subcutaneous adipose tissue of nonobese and obese humans.

Studies have shown evidence of production of nitric oxide (NO) in adipose tissue, as well as inhibition of lipolysis by NO. We have analyzed nitric oxide synthase (NOS) expression in subcutaneous adipose tissue from 13 nonobese and 18 obese male subjects. Using a competitive reverse transcription polymerase chain reaction method, endothelial (eNOS) and inducible (iNOS), but not neuronal (nNOS), nitric oxide synthase mRNA expression was detected in isolated fat cells and pieces of adipose tissue. Tissue mRNA levels for eNOS were 3,814 +/- 825 and 5,956 +/- 476 amol/mg RNA (P = 0.043), and for iNOS 306 +/- 38 and 332 +/- 48 amol/mg RNA, for nonobese and obese individuals, respectively. Western blotting revealed similar eNOS protein levels in isolated fat cells and adipose tissue pieces. Protein levels for eNOS in nonobese and obese individuals, respectively, were (in optical density [OD] units per mm(2) per 100 microgram of total protein) 0.11 +/- 0.08 and 2.80 +/- 1.30 (P = 0.043). iNOS protein was detectable, but not measurable, at low levels in a subset of obese patients (3 of 10). iNOS protein levels could not be detected in nonobese individuals. Hormone-sensitive lipase (HSL), the key regulating enzyme in lipolysis, is reduced in obesity. The expression of HSL protein in subcutaneous adipose tissue was studied in the same subset of patients; in agreement with previous results, HSL levels were reduced in obese subjects: 4.64 +/- 1.10 and 1.27 +/- 0.35 (P = 0.012) in nonobese and obese subjects, respectively. In conclusion, this study shows that eNOS and iNOS, but not nNOS, are present in human subcutaneous adipose tissue. Gene expression and protein levels of eNOS are increased, whereas HSL protein levels are decreased in obesity. It is speculated that increased NO production, preferably by eNOS, and decreased HSL levels may cause decreased subcutaneous adipose tissue lipolysis in obesity. synthases in subcutaneous adipose tissue of nonobese and obese humans.

No effect of carvedilol on nitric oxide generation in phagocytes but modulation of production of superoxide ions.

Since carvedilol has been claimed to possess antioxidative effects, this drug might affect functional responses, including nitric oxide (NO) generation, of polymorphonuclear neutrophils (PMN) and macrophages. When we assessed the effects of carvedilol on PMN responses in vitro, we observed that carvedilol dose dependently modulated generation of superoxide ions by NADPH oxidase when induced by the formylpeptide formyl-methionyl-leucyl-phenylalanine (fMLP) or the phorbol ester phorbol myristate acetate. This effect was not coupled to diminished phospholipase C activity. In contrast to the effect on NADPH oxidase, neither the fMLP-elicited NO generation by PMN nor the response of the murine macrophage cell line J774 to lipopolysaccharide was affected. There was no evidence from cell-free assay systems that carvedilol is a scavenger for superoxide ions or NO. Moreover, carvedilol did not affect other reactions dependent on NO, e.g. spontaneous or fMLP-stimulated PMN migration or lipoxin A(4)-, fMLP-, or A23187-induced neutrophil cytotoxicity for human umbilical vein endothelial cells. Thus, these effects point to the possibility that carvedilol modulates the NADPH oxidase of PMN but leaves the nitric oxide synthase of phagocytes intact.

Electrochemical detection of nitric oxide production in human polymorphonuclear neutrophil leukocytes.

The detection of nitric oxide (NO) release by human polymorphonuclear neutrophil leukocytes (PMNs) presents several difficulties, mainly due to concomitant production of O2- and H2O2, which could interfere with the measurements. A Nafion and nickel porphyrin-coated microelectrode was used to measure NO production in PMNs in vitro. It allowed detection of 6.3 +/- 1.9 nM NO in a PMN-containing system and was unaffected by added chemicals. Addition of the chemotactic oligopeptide f-met-leu-phe (fMLP; 100 nM) induced a NO release which reached a value of 71 +/- 30 pmol NO/10(6) PMN x ml(-1) 5 min after stimulation in the presence of SOD (150 U/ml). If SOD was omitted, the corresponding value was 36 +/- 20 pmol NO/10(6) PMN x ml(-1). Presence or absence of catalase did not alter the amount of NO measured. Addition of the NO-synthase inhibitor N(G)-monomethyl-L-arginine (LNMMA; 1 mM) reduced the current by 82 +/- 20%. These results agree with the rate of NO production in human PMNs when measured spectrophotometrically using the NO-dependent oxidation of oxyhaemoglobin to methaemoglobin. The NO production in human PMN was dependent on fMLP concentrations, but independent of cell-concentrations of 0.5-3.5 x 10(6)/ml. This paper shows that a electrochemical method, e.g. Nafion and porphyrin-coated microelectrode, is suitable for studies of NO release from stimulated human PMNs.

Impaired granulocyte formylpeptide-induced superoxide generation in chronically ill, malnourished, elderly patients.

OBJECTIVE: Protein-energy malnutrition (PEM), often occurring in patients with chronic disease, is associated with a decreased capacity to combat infections. In this study we assessed polymorphonuclear neutrophil (PMN) superoxide anion (*O2-) formation in elderly PEM patients with various chronic diseases. DESIGN AND SUBJECTS: Nineteen patients (75+/-1 years), with body mass index 17.1+/-0.4, and 19 age-matched healthy controls were included. Fourteen patients and 14 controls were re-examined in a 3 month follow-up. SETTING: A service of internal medicine at a university-affiliated hospital. INTERVENTIONS: Eight patients were prescribed a dietary liquid supplementation during the observation period. MAIN OUTCOME MEASURES: Superoxide production in PMN induced by fMLP (a receptor ligand) and phorbol myristate acetate (PMA), which acts directly on protein kinase C. RESULTS: fMLP-induced superoxide generation in the malnourished patients was 55+/-5% of that of the controls. However, the patients retained their capacity, 108+/-6% of control PMN generation, to respond to PMA. In those who received formula supplementation, fMLP-generated *O2- production levels were 48+/-8 and 73+/-13% (P = 0.12) of those of controls at the start and after 3 months, respectively. Corresponding figures in those who were not prescribed supplementation were 57+/-8 and 64+/-4% (P = 0.55). CONCLUSION: Possibly contributing to reduced host defence, receptor ligand-induced PMN generation of *O2 is significantly lower in chronically ill, elderly patients with PEM than in age-matched healthy controls.

Gamma interferon treatment of patients with chronic granulomatous disease is associated with augmented production of nitric oxide by polymorphonuclear neutrophils.

Treatment with gamma-interferon (IFN-gamma) is associated with reduced frequency and severity of infections in chronic granulomatous disease (CGD), but the mechanism is unknown. Since the inducible nitric oxide (NO) synthase can be amplified by IFN-gamma in murine macrophages, for example, we hypothesized that IFN-gamma might modulate NO release from polymorphonuclear neutrophils (PMNs) in patients with CGD. Eight patients with CGD and eight healthy controls were studied. Each patient was given either 50 or 100 microg of IFN-gamma per m2 on two consecutive days. The production of NO from N-formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated PMNs was assessed as the NG-monomethyl-L-arginine-inhibitable oxidation of oxyhemoglobin to methemoglobin in the presence of catalase and superoxide dismutase. Prior to IFN-gamma treatment, the PMNs from CGD patients produced 372 +/- 27 (mean +/- standard error of the mean) pmol of NO/10(6) PMNs at 45 min, while the control PMNs produced 343 +/- 44 pmol. On day 1 after IFN-gamma treatment, NO production increased to 132% +/- 25% of that for controls, and on day 3 it reached 360% +/- 37% (P < 0.001) of that for controls. On day 8, the values still remained higher, 280% +/- 78% more than the control values. Likewise, the bactericidal capacity of PMNs increased on day 3. The present data show that IFN-gamma treatment of CGD patients is associated with an increased production of NO from PMNs when activated by fMLP. Since these PMNs lack the capacity to produce superoxide anions, it is conceivable that this increase in NO release could be instrumental in augmenting host defense.

Activation of nitric oxide release and oxidative metabolism by leukotrienes B4, C4, and D4 in human polymorphonuclear leukocytes.

Because arachidonate metabolites are potent mediators of inflammation, we have studied the effects of leukotriene B4 (LTB4) and the cysteinyl leukotrienes C4 and D4 (LTC4 and LTD4) on the release of nitric oxide (NO), in vitro, by human polymorphonuclear granulocytes (PMN). Two independent and highly sensitive real-time methods were used for these studies, ie, the NO-dependent oxidation of oxyhemoglobin (HbO2) to methemoglobin and a NO-sensitive microelectrode. When activated with LTB4, LTC4, or LTD4, but not with other lipoxygenase products such as 5S-HETE, 5-oxo-ETE or 5S, 12S-diHETE, PMN produced NO in a stimulus- and concentration-dependent manner. The rank order of potency was LTB4 = LTC4 > LTD4, corresponding to 232 +/- 50 pmol of NO/10(6) PMN for 100 nmol/L LTB4 after 30 minutes. The kinetic properties of the responses were similar for all three leukotrienes with a maximum response at 13 +/- 3 minutes. Cysteinyl leukotriene and LTB4 antagonists inhibited the agonist-induced NO production by 70%, and treatment with Bordetella pertussis toxin, or chelation of cytosolic Ca2+, [Ca2+]i, also efficiently inhibited this response. In contrast, treatment of PMN with cytochalasin B (5 microg/mL) enhanced the LTB4-induced NO formation by 86%. Thus, this is the first demonstration that the cysteinyl leukotrienes LTC4 and LTD4, as well as LTB4, activate NO release from human PMN by surface receptor, G-protein and [Ca2+]i-dependent mechanisms. This effect differs from activation of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, for which only LTB4 is an activator.

Stimulus-dependent transduction mechanisms for nitric oxide release in human polymorphonuclear neutrophil leukocytes.

The production of nitric oxide (NO) may play an important role in functional responses of the human polymorphonuclear neutrophil granulocytes (PMNs). Others have described the presence of both an inducible, Ca2+-independent and a constitutionally expressed, Ca2+-dependent nitric oxide synthase (NOS) in human PMNs. However, the conditions for production and release of NO in human PMNs are still largely unknown. We assessed mechanisms for activation of NO release from human PMNs and particularly the dependence on extracellular and intracellular Ca2+. We addressed this question by applying a variety of agonists with known and differing mechanisms of activation in PMNs and measuring the released NO by two highly sensitive and specific real-time methods for detection of NO, the oxidation of oxyhemoglobin to methemoglobin and an electrochemical method. We found that human PMNs activated with the surface receptor-dependent agonist, N-formyl-methionyl-leucyl-phenylalanine (fMLP); the calcium ionophore, A23187; or the direct stimulator of protein kinase C, phorbol myristate acetate (PMA), produced NO which was inhibited by a specific NOS inhibitor, NG-monomethyl-L-arginine. The NO production induced by fMLP or A23187 was dependent on the presence of extracellular Ca2+, but this was not the case for PMA. The stimulatory effect of fMLP was almost completely inhibited by Bordetella pertussis toxin. These results indicate an NOS activity in purified human PMNs in vitro, and the transduction mechanisms for the agonists used show strong similarity with previously known pathways for other neutrophil functions.

Measurement of methemoglobin formation from oxyhemoglobin. A real-time, continuous assay of nitric oxide release by human polymorphonuclear leukocytes.

We have evaluated the spectrophotometric measurement (at 401 vs. 411 nm) of nitric oxide (NO)-dependent methemoglobin formation from oxyhemoglobin in order to assess NO release from human polymorphonuclear neutrophil leukocytes (PMN). S-nitroso-D,L-acetyl-penicillamine (SNAP, 25-200 microM), a donor of NO, induced a dose-dependent methemoglobin formation. Furthermore, when PMN were activated with N-formyl-methionylleucyl-phenylalanine or phorbol myristate acetate in the presence of superoxide dismutase (SOD) and catalase, methemoglobin formation ensued. The amount of methemoglobin formed was dependent on the amounts of oxyhemoglobin and stimulus used, and the number of PMN in the assay. The NO synthase (NOS) inhibitors NG-monomethyl-L-arginine or nitro-L-arginine methyl ester did not affect methemoglobin generation from oxyhemoglobin induced by SNAP but inhibited that mediated by activated PMN with IC50 values of 250 microM and 340 microM, respectively. The substrate for NO formation from NOS, L-arginine in concentrations up to 1 mM did not significantly influence the methemoglobin formation either induced by SNAP or activated PMN. Exclusion of SOD did not affect SNAP-dependent oxidation of oxyhemoglobin. Exclusion of SOD from the cell-containing system attenuated methemoglobin formation, and if catalase was also excluded the response was further reduced. Finally, PMN from a patient with X-linked chronic granulomatous disease, unable to produce superoxide anions, showed a similar production of methemoglobin from HbO2 as did healthy PMN, activated with the respective agonists. We conclude that spectrophotometric measurement of methemoglobin formation from oxyhemoglobin in the presence of SOD and catalase is a suitable method for the measurement of NO release from PMN, with the benefits of a real-time, continuous assay.

The role of nitric oxide in lipoxin A4-induced polymorphonuclear neutrophil-dependent cytotoxicity to human vascular endothelium in vitro.

OBJECTIVE: To assess the mechanism for the cytotoxicity of human polymorphonuclear neutrophils (PMN) to human umbilical vein endothelial cells (HUVEC) induced by the 5- and 15-lipoxygenase product of arachidonate, lipoxin A4 (LXA4), and the phorbol ester, phorbol myristate acetate (PMA). METHODS: HUVEC were grown to confluence and labeled with 51Cr. PMN and stimuli were added, and the release of 51Cr into supernatants was assessed after 4 hours. RESULTS: Both LXA4 and PMA conferred highly significant PMN-dependent cytolysis. The cytotoxicity activated by LXA4 was inhibited by NG-monomethyl-L-arginine (L-NMA) and by nitro-L-arginine methyl ester, specific inhibitors of the nitric oxide (NO)-producing enzyme NO synthase. Also, the scavenger of extracellular NO, oxyhemoglobin (HbO2), prevented LXA4-induced cytolysis in a dose-dependent manner. In sharp contrast, L-NMA did not significantly affect the cytolysis induced by PMA, whereas HbO2 showed a modest inhibitory action. In experiments without PMN, addition of the NO donor S-nitroso-N-acetyl-penicillamine to HUVEC induced marked cytolysis, which was inhibited by HbO2, but not by L-NMA. Addition of L-arginine or arginine analogs did not affect superoxide anion production in a cell-free hypoxanthine/xanthine oxidase system. Both LXA4 and PMA induced the production of superoxide anion from PMN and of NO from HUVEC: CONCLUSION: NO produced by HUVEC, interacting with PMN which produce superoxide anions, is of marked significance for the endothelial cell damage in this in vitro model of vasculitis. This is probably due to the subsequent formation, via a radical-radical interaction between NO and .O2-, of cytotoxic products, such as peroxynitrite and its metabolites. Furthermore, although LXA4 and PMA induced comparable cytolysis at optimal concentrations, the relative importance of NO compared with other mechanisms mediating cytotoxicity was stimulus dependent, and NO was relatively more important for LXA4-induced PMN-dependent endothelial injury.

Neutrophil membrane potential changes and homotypic aggregation kinetics are pH-dependent: studies of chronic granulomatous disease.

Activated polymorphonuclear neutrophil granulocytes (PMN) from patients with chronic granulomatous disease (CGD) show reduced electron-proton shifts and an inability to acidify the cell. We studied whether this impaired pH-regulating capacity affected PMN membrane potential changes and the kinetics of homotypic aggregation by changing the extracellular pH over a wide range. At pH 7.4 normal PMN showed a rapid, transient membrane depolarization to leukotriene B4 (LTB4) and a slower response to N-formyl-methionyl-leucyl-phenylalanine. In contrast, PMN from 13 patients with CGD exhibited no or minute depolarization to these stimuli and 77% of tested patients with CGD displayed absence or marked reductions of the disaggregation to LTB4. On acidification of pH 5.0 to 6.4, PMN membrane depolarization appeared in six of nine tested patients. Likewise, disaggregation became evident in all of three patients. On alkalinization of normal PMN to pH 8.0 to 9.0, membrane depolarization and disaggregation to LTB4 disappeared, and cells reacted as CGD PMN. This change was not due to inefficient signal transduction, because normal PMN enhanced the superoxide ion production to N-formyl-methionyl-leucyl-phenylalanine on this alkalinization. Cytosolic pH changes in resting and LTB4-activated CGD cells at pH 6.0, 7.4, and 8.5 were similar those in control cells but for absence of an initial acidification. Thus neutrophil membrane potential changes and aggregation kinetics to LTB4 are abnormal in patients with CGD and return toward normal on extracellular acidification.

Natural interferon-alpha in combination with melphalan/prednisone versus melphalan/prednisone in the treatment of multiple myeloma stages II and III: a randomized study from the Myeloma Group of Central Sweden.

Three hundred thirty-five previously untreated patients with multiple myeloma in clinical stages II and III entered a randomized trial comparing intermittent oral melphalan and prednisone (MP) therapy (n = 171) with MP in combination with natural (leukocyte-derived) alpha-interferon (MP/IFN) (n = 164). The treatment groups were comparable with regard to major prognostic factors. The response frequency was 42% in the MP group and 68% in the MP/IFN group (P < .0001). Eighty-five percent of IgA myelomas and 71% of Bence-Jones myelomas responded to MP/IFN compared with 48% and 27%, respectively, to MP treatment (P = .001). There was no difference in the overall survival between the two treatment groups. However, the survival of 72 patients with IgA or Bence-Jones myeloma randomized to receive MP/IFN was significantly longer (median 32 months) than that of 71 patients treated with MP (median 17 months) (p < .05). No statistically significant difference in response frequency (60% v 46%) or survival was found for patients with IgG myeloma. Hematologic toxicity, WHO grades III and IV, was higher in the MP/IFN group (48%) than in the MP group (33%) (P < .05) during the induction treatment period. Flulike syndrome was observed in 68% of patients receiving MP/IFN. The results show that MP/IFN is a well-tolerated treatment regimen, superior to MP for remission induction, and it improves significantly the overall survival for patients with IgA and Bence-Jones myelomas.

Treatment of multiple myeloma with interferon alpha: the Scandinavian experience.

IFN alpha is a biologic therapeutic agent with documented antitumoral effect in multiple myeloma. 15% of previously untreated myeloma patients achieve a clinical response to IFN alpha alone with a possible dose-response relationship. A particularly good effect is noted in IgA myelomas treated with natural IFN alpha. A randomized study was started in April 1986 comparing melphalan/prednisone (MP) therapy with MP plus natural IFN alpha (MP/IFN) in untreated patients with multiple myeloma stages II and III. 220 patients had entered the study by autumn 1989. An interim report is given here. The response frequency was 48% in the MP group and 66% in the MP/IFN group (P less than 0.02). Stage II patients responded better to MP/IFN (76%) than to MP alone (48%) (P less than 0.01). No significant difference was noted for stage III patients. 91% of all IgA myelomas responded to MP/IFN and 52% to MP (P less than 0.01). The difference in response frequency of IgG and BJ myelomas between the two treatment groups was not statistically significant. The observation period is still too short to draw firm conclusions on survival. However, a statistically significant longer response duration time and survival from response (P less than 0.01) was noted for stage II patients.

Effects of an essential fatty acid-supplemented diet on leukotriene B4-induced rat neutrophil functions.

This study evaluated the effect of dietary supplementation with the essential fatty acid linoleic acid to 10% of the energy content of a diet on the stimulus-response coupling of rat peritoneal neutrophils. When stimulated with leukotriene B4 neutrophils from essential fatty acid supplemented rats responded with a significantly more pronounced oxidative metabolism (assessed as luminol augmented chemiluminescence) relative to control cells from rats on a normal 3% of total energy essential fatty acid diet. Chemiluminescence response to the formylpeptide N-formyl-norleucyl-leucyl-phenylalanine-norleucyl-thyrosyl-leucine was similarly enhanced. In contrast, responses elicited by the lectin concanavalin A did not differ between the two dietary groups. In response to leukotriene B4 a dose-related inhibition of neutrophil aggregation was observed, whereas chemotaxis did not differ between the two groups. Thus, linoleate supplementation is associated with a stimulus-specific modulation of neutrophil oxidative and aggregatory responses suggesting an effect on early, conceivably receptor-linked, steps of the stimulus-response coupling.

The effect of 20-trifluoromethyl leukotriene B4 on neutrophil functional responses.

20-trifluoromethyl-leukotriene B4 (20CF3-LTB4) is a stable derivative of leukotriene B4 (LTB4) that is not subjected to omega-oxidation to less active metabolites. 20CF3-LTB4 was as potent as LTB4 as a chemotactic, adhesion-promoting and aggregatory agent for human neutrophils, but had only 11 +/- 3% of the ability to induce an oxidative response. Nonetheless, both compounds were equally efficient in order to confer a rapid and monophasic increment of the concentration of cytosolic calcium. The kinetics of the calcium, aggregatory and chemiluminescent responses to 20CF3-LTB4 were similar to that of LTB4. These findings suggest that the insertion of the trifluoromethyl group into the LTB4 molecule causes a shift of the biological activity profile, suggesting that 20CF3-LTB4 binds mainly to high affinity LTB4 receptors. Moreover, the similarity of the response kinetics of LTB4 and 20CF3-LTB4 suggests that the mechanism for the rapid and transient responses of LTB4 is not due to its omega-oxidation.

Dietary linoleate supplementation modulates formyl-peptide receptor expression and functional responses of rat neutrophils.

We studied effects of dietary supplementation with the essential fatty acid (EFA) linoleic acid (LA) to see if neutrophil responses would be modulated. Neutrophils from rats maintained on a diet supplemented with EFA to 10% of the energy content--the high EFA (HEFA) group--showed a significantly higher LA concentration (but similar arachidonic acid content) compared with neutrophils from control rats maintained on a standard diet with 3% of the energy content as EFA. The HEFA group showed a significantly higher neutrophil oxidative metabolism compared with controls in response to N-formyl-methionyl-leucyl-phenylalanine (FMLP), but this response was equal to control values when stimulated by ionophore A23187, sodium fluoride, or phorbol myristate acetate. Similarly, FMLP conferred a more pronounced increase of intracellular Ca2+ in HEFA neutrophils, whereas this response to ionomycin was equal to that in controls. In contrast, HEFA rat neutrophil migration was decreased to 71% of the value in controls in response to FMLP. Similar results were observed for aggregation responses. On A23187 stimulation, HEFA and control neutrophils generated equal amounts of leukotriene B4 and other 5-lipoxygenase products as well as thromboxane B2 and 6-keto-prostaglandin F1 alpha. However, assessment of binding of FMLP labeled with tritium revealed an increase of the low affinity state of the FMLP receptor population. Thus an increased intake of one unsaturated fatty acid, LA, leading to its accumulation in neutrophils, conferred alterations in formyl-peptide-elicited responses, not associated with the formation of the assessed arachidonate-derived mediators, but most likely through the observed modulation of FMLP receptor subpopulations.

Oral versus intravenous melphalan and prednisone treatment in multiple myeloma stage II. A randomized study from the Myeloma Group of Central Sweden.

Eighty-one previously untreated patients with multiple myeloma stage II entered a randomized trial comparing oral melphalan (0.25 mg/kg/day; n = 40) with intravenous melphalan (0.125 mg/kg/day; n = 41) in combination with oral prednisone (2 mg/kg/day). The courses were given for 4 days and repeated every sixth week. The treatment groups were well comparable with regard to major prognostic factors. There was no statistically significant difference in the response rates, the response duration times and the survival times. No significant difference in nonhematological and hematological toxicity was noted. Since intravenous administration of melphalan did not result in a substantial increase in response rate or survival, this study supports the use of oral melphalan/prednisone as first-line therapy for patients with multiple myeloma.

Substance P activates and modulates neutrophil oxidative metabolism and aggregation.

The substance P (SP) fragment SP(7-11) induced chemiluminescence (CL) and aggregation in human neutrophils at high concentrations (greater than or equal to 10 microM), whereas the entire molecule SP(1-11) was less potent and the SP(1-4) fragment was inactive. At these concentrations SP and its fragments also inhibited CL and aggregation evoked by subsequent addition of formyl-methionyl-leucyl-phenylalanine (fMLP), an effect that may depend on desensitization. However, at lower concentrations (1-10 nM) SP was able to prime human neutrophils to enhanced CL and enzyme release stimulated by fMLP. These findings indicate that, in addition to direct activation of CL and aggregation, SP also modulates neutrophil function and can thus amplify the release of potentially cytotoxic substances, a possible mechanism for nervous system involvement in rheumatoid arthritis.

Alternating combination chemotherapy (VMCP/VBAP) is not superior to melphalan/prednisone in the treatment of multiple myeloma patients stage III--a randomized study from MGCS.

86 previously untreated patients with multiple myeloma stage III entered a randomized trial comparing combination chemotherapy (VMCP/VBAP) (n = 42) with intermittent oral melphalan and prednisone (MP) treatment (n = 44). The treatment gropus were well comparable with regard to major prognostic factors. There was no statistically significant difference in the response rates, 52% (VMCP/VBAP) vs 61% (MP); in the response duration times, median 19 months vs 22 months, or in the survival times, median 24 months vs 28 months. However, survival of patients older than 65 years was significantly shorter in the VMCP/VBAP group (median 15 months) compared to the MP group (median 23 months) (p = 0.03). No significant difference in non-hematological or hematological toxicity was noted. The study further supports the notion that MP therapy should be used as primary standard treatment for patients with multiple myeloma.