KRD (carfilzomib and lenalidomide plus dexamethasone) for the treatment of relapsed or refractory multiple myeloma in the real-life: a retrospective survey in 123 patients

From April 2016, carfilzomib, in combination with lenalidomide and dexamethasone (KRD), became available for use in the daily practice in Italy for patients with relapsed or refractory multiple myeloma (RRMM). We performed a retrospective survey at 14 different institutions from Southern Italy in order to evaluate patient characteristics and treatment results from an unselected series of patients treated accordingly so far. One hundred and twenty-three consecutive patients were included, with a median of 2 previous lines of therapy (range 1-9) and a median age of 63 years (range 39-82). At the time of analysis, median number of courses administered is 11 (range 1-34), and all patients are evaluable for response. Overall response rate including complete remission, very good partial remission, and partial remission is 85%. After a median follow-up of 27 months, median overall and progression-free survival are 33 and 23 months, respectively. Sixty-three patients are alive and between them, 45 (37%) are in continuous remission. Sixty patients have died (49%), mainly from progressive disease. There were 6 treatment-related deaths (5% of the whole patient population). Overall, hematological and non-hematological toxicity were manageable, mostly on outpatient basis. Arterial hypertension has been observed in 43 cases (35%) but did not lead to treatment interruption. Our data demonstrate that in real life, KRD is highly effective and well tolerated in the majority of patients with RRMM.

Combination of all-trans-retinoic acid and gemtuzumab ozogamicin in an elderly patient with acute promyelocytic leukemia and severe cardiac failure

All-trans-retinoic acid (ATRA) combined with anthracyclines is currently the standard treatment for acute promyelocytic leukemia (APL). In elderly patients the presence of comorbidities, such as cardiomyopathy or different organ failures, often represents an absolute contraindication to standard chemotherapy. In this particular setting of patients, alternative front-line approaches are needed. Here we report the use of gemtuzumab ozogamicin as consolidation therapy in a 68-year-old patient not eligible for standard dose anthracycline due to severe cardiac failure and chronic anticoagulant therapy, affected by low-risk APL. Induction therapy was started with ATRA alone, at a dose of 45 mg/m2 for 80 days. The patient obtained a complete hematological and molecular remission. At day +170 the patient was treated with 6 mg/m2 gemtuzumab ozogamicin monthly for two months (2 total doses) as a consolidation therapy and then started a maintenance program with ATRA 45 mg/m2 for 15 days every three months, for a total time of two years. No adverse events were observed in every phase of treatment and the patient is still in complete continuous hematological and molecular remission 29 months from diagnosis. This approach represents an intriguing therapeutic option to be investigated in randomized studies in low- and intermediate-risk elderly patients (older than 65 years), aiming to minimize or to eliminate standard chemotherapy in advantage of new non-conventional agents, including ATO.

[The problem of the aged person living alone: a methodological proposal for a pilot project of the aged person's and university student's cohabitation]

The objective of the present study was to evaluate the outcome of a promotion program for the cohabitation between healthy living-alone-old person and university student. The study aimed to highlight the benefits of both the parts in terms of psyco-physical behaviour of the old subject and of logistic and financial support for the student. The survey was carried out between 1998 and 2000 on voluntary couples of old person-university student living in Padua. The study quantified the level of satisfaction of the material needs of the both parts and it also showed the affective relationship established between the old people and the young subjects.

[Immediate post-extraction implant in infected site. An eight-year clinical and radiographic control]

The use of immediate post-extraction implants presents several advantages in term of reduction of surgical steps and time required to conclude the therapy. Particularly important is the possibility to minimize the bone loss that otherwise would occur in the physiologic healing of the alveolus. Many authors agree that an infected site is one of the main contraindications to use post-extraction implants. In spite of this, favourable results have been reported also in these conditions. In this study, an immediate post-extraction implant has been placed to substitute the maxillary left second premolar, extracted due to vertical root fracture. Suppuration with fistula in the vestibule was present. The residual wide bone defect at the end of the debridement of the surgical socket has made it necessary a regenerative procedure by means of e-PTFE membrane, at the same time of implant insertion. After 9 month-healing the membrane has been removed and the implant exposed to perform the prosthetic procedures. The clinical and radiographic control after 8 years prove that infection in the surgical site has not compromised the final success, even in the long-term observation, suggesting the need to re-evaluate the contraindications conventionally reported.

Point-of-care testing of cardiac markers: results from an experience in an Emergency Department

AIM

An experimental approach to the use of point-of-care testing for cardiac markers in the Emergency Department (ED) of our Institution has been carried out using two devices (SCS, Dade Behring and Triage Cardiac Panel, Biosite Diagnostics) for the measurement of cardiac markers.

RESULTS

(1) From the analytical point of view, a fundamental tool for an efficient management of patients was the agreement between results from point-of-care testing and from the instruments located in STAT lab and/or central laboratory: in about 5% of patients, a lack of comparability of data, resulted in an inappropriate admission of patients (medical vs. intensive care unit). (2) The actual total turnaround time (TAT) in the management of samples sent to STAT lab was estimated to be equal to 82.5 min (50th percentile). (3) In the same organizational setting, the use of a point-of-care device produced a turnaround time equal to 17 min (50th percentile). (4) The reduction in turnaround time resulted in a faster discharge for five patients who had normal ECG findings and cardiac marker values, the Delta time (POCT-STAT lab) ranging from -10 to -70 min.

CONCLUSIONS

The point-of-care option evaluated also in relation to personnel issues for staff working in the ED, brought some interesting questions about the characteristics of POCT devices (easy to use 100%, safety for operator 91%) and the obtained results (quantitative and correlated to STAT lab, 91%), as well as the need of other options such as the implementation of rapid tube sample delivery.

Clinical outcome of patients with internal carotid artery occlusion: a prospective follow-up study

PURPOSE

We prospectively evaluated whether, and to what extent, different clinical presentations (symptomatic or asymptomatic) or the presence of atherosclerotic narrowing of the contralateral carotid system modifies the mortality rate and the incidence of nonfatal cerebrovascular events in patients with internal carotid artery (ICA) occlusion.

METHODS

A prospective cohort study was conducted in the Unit Care of Angiology at the University Hospital of Padua in Italy. Consecutive patients with ICA occlusion were eligible for the study. Between 1990 and 1991, 41 such patients were identified at our center. All patients were observed prospectively for a mean of 44.5 months, except for one patient who was lost to follow-up after 12 months. Patients with severe (ie, more than 75%) stenosis of the contralateral internal carotid artery were scheduled for thromboendarterectomy. ICA occlusion was objectively documented in all patients by using a combination of echo-color Doppler scanning and continuous-wave Doppler scanning (periorbital flow).

RESULTS

The overall mortality rate was 22.0% (95% CI, 10.6-37.6), and the stroke-related mortality rate was 7.3% (95% CI, 1.5-19.9). No differences in overall and stroke-related mortality rates were observed between asymptomatic and symptomatic patients. None of the patients experienced nonfatal cerebrovascular events.

CONCLUSION

ICA occlusion seems to represent a relatively benign condition, in both its symptomatic and asymptomatic presentation. The presence of an atherosclerotic stenosis less than 75% of the contralateral ICA does not seem to worsen the prognosis of this condition.

Recombinant human relaxin in the treatment of scleroderma. A randomized, double-blind, placebo-controlled trial

BACKGROUND

Relaxin is a pregnancy-related hormone that has tissue remodeling and antifibrotic effects. Systemic sclerosis (scleroderma) is characterized by fibrosis of the skin, vasculature, and internal organs.

OBJECTIVE

To assess the efficacy, safety, and dose-response effect of recombinant human relaxin in patients with scleroderma.

DESIGN

Multicenter, parallel-group, randomized, double-blind, placebo-controlled trial.

SETTING

Academic referral centers.

PATIENTS

68 patients who had had stable, diffuse scleroderma (moderate to severe) for less than 5 years.

INTERVENTION

Recombinant human relaxin, 25 or 100 microg/kg of body weight per day, or placebo administered by continuous subcutaneous infusion over 24 weeks.

MEASUREMENTS

Modified Rodnan skin score was the primary efficacy measure. Secondary measurements were pulmonary function, the Health Assessment Questionnaire, and other measures of scleroderma that reflected fibrosis.

RESULTS

Patients who received 25 microg/kg of recombinant human relaxin per day had significantly lower skin scores than those who received placebo (mean change, -3.6 at 4 weeks [P = 0.021], -7.5 at 12 weeks [P < 0.001], and -8.7 at 24 weeks [P = 0.040]). Similar trends were noted in other outcome measures, including forced vital capacity, measures of oral aperture and hand extension, functional status, and global assessment. Patients who received 100 microg/kg of relaxin per day did not differ from those who received placebo. Drug-related adverse events included menometrorrhagia, reversible anemia, and complications of the subcutaneous drug administration system (site irritation and local infection).

CONCLUSIONS

Twenty-four weeks of recombinant human relaxin, 25 microg/kg per day, is associated with reduced skin thickening, improved mobility, and improved function in patients with moderate to severe diffuse scleroderma.

Prolonged response to cyclosporin-A in hypoplastic refractory anemia and correlation with in vitro studies

BACKGROUND AND OBJECTIVE

Lymphocyte abnormalities in myelodysplastic syndromes (MDS) have been widely described, but the role of the immune system in the pathogenesis of these clonal disorders remains controversial. An active role of lymphocytes in suppressing normal hematopoiesis may be implicated in MDS with hypoplastic marrow. We have studied in vitro and in vivo activity of cyclosporin-A (CSA) on hematopoiesis in patients affected by hypoplastic MDS without blast excess.

DESIGN AND METHODS

Nine consecutive patients with hypoplastic refractory anemia (RA), followed up in our out-patient unit, were treated with CSA at daily doses of 1-3 mg/kg for at least three months. Low dose steroids or danazol were transiently added in 7/9 patients. Differences between pre- and post-treatment parameters were studied by the Student's t-test. In vitro effect of CSA on circulating hematopoietic progenitors was studied by the methylcellulose colony assay.

RESULTS

Before treatment, fewer circulating hematopoietic progenitors were found in all patients as compared to normal subjects. The number of CD34+ cells was about halved, while circulating erythroid and myeloid colony-forming cells (CFC) were reduced to one-fifth. After a mean period of 22 months of CSA treatment (median: 14.5 months), hemoglobin was significantly and persistently increased in two patients, platelets in one, platelets and hemoglobin in two. Two patients showed transient responses, one patient did not tolerate the treatment and one patient is close to a significant response. At in vitro CSA concentrations similar to those achieved in vivo after oral administration the drug significantly increased cell colony growth in hypoplastic RA. This test correctly predicted a positive clinical response to CSA in 3/5 cases and treatment failure in 4/4 cases.

INTERPRETATION AND CONCLUSIONS

About one half of hypoplastic RA patients benefited from CSA treatment. A larger study could verify whether in vitro culture of hematopoietic progenitors in the presence of CSA can predict the clinical response and whether this treatment could prolong patients' survival.

Reversible adult respiratory distress in primary antiphospholipid syndrome

Antiphospholipid antibody syndrome (APS) is a disorder caused by circulating antibodies reacting with biological membranes and characterized by recurrent thrombosis, chronic thrombocytopenia and miscarriages. It has been reported to occur either as a primary syndrome or secondary to systemic autoimmune disorders. We describe a case of primary APS in a young patient, in whom the clinical course was particularly severe and complicated by a respiratory distress syndrome. The patient was resistant to a number of treatments, and eventually responded to intravenous high dose corticosteroids.

Increased CA 125 serum levels in patients with advanced acute leukemia with serosal involvement

BACKGROUND

CA 125 is a tumor marker used for the diagnosis and monitoring of ovarian carcinoma. This marker also has been found to be increased in patients with serosal effusion derived from nonneoplastic inflammatory disease and in a few instances of advanced non-Hodgkin lymphoma with serosal involvement.

METHODS

CA 125 levels were tested in the serum of 15 patients with acute myeloblastic leukemia (AML) at the time of diagnosis and in 3 patients with advanced leukemia with serosal involvement. In two patients with elevated serum CA 125 levels, a CA 125 assay was performed on leukemic cells and on the supernatant fluid of short term liquid culture.

RESULTS

Increased serum CA 125 was found in the three patients with acute leukemia with extramedullary localization and serosal effusion, whereas it was normal in 15 AML patients tested at the time of diagnosis. CA 125 was not detectable in leukemic cell extracts nor in the supernatant fluid of primary cultures.

CONCLUSIONS

These results indicate that leukemic cells were unable to produce CA 125 and suggest that its elevation in the serum is likely due to a serosal inflammatory reaction caused by the leukemic infiltration.

[Chronobiology of acute pulmonary edema in an emergency service]

Some diseases like acute myocardial infarction, sudden death and stroke have been reported to disclose daily, weekly or annual incidence fluctuations. We analyzed the rhythm of pulmonary edema occurrence. We considered 105 consecutive subjects (mean age 73.7 +/- 9.7 years) who came to an Emergency Department because of acute pulmonary edema during a solar year. Chronobiologic analysis was performed using Halberg single cosinor test. Pulmonary edema incidence was higher during the night with an acrophase at 2:14 a.m. (p < 0.001). No significant weekly or circannual rhythms were detected. We discuss the possible relations with diminished heart output, increase in sympathetic tone or partial baroceptor desensitization, occurring at night.

Safety and pharmacokinetics of recombinant human relaxin in systemic sclerosis

OBJECTIVE

To investigate the safety and pharmacokinetics of a 28 day continuous subcutaneous infusion of recombinant human relaxin in patients with systemic sclerosis with diffuse scleroderma.

METHODS

Thirty patients with stable diffuse scleroderma of moderate severity received recombinant human relaxin at 6, 12, 50, 100, and 200 microg/kg/day or placebo in a double blind, sequential panel, dose escalation study.

RESULTS

All patients completed 28 days of study treatment. Steady state concentrations of serum relaxin were achieved by the 3rd day of infusion and were dose proportionate. Patients receiving 200 microg/kg/day achieved levels about 50-fold those of normal pregnancy. Pharmacokinetics of relaxin were nonlinear with hyperbolic increases of both t1/2 and volume of distribution and parallel decrease of elimination rate coefficient. An elimination transport system was suggested with saturation at serum relaxin concentration of 45 ng/ml. Adverse events included local infusion site rash and pain, minor bleeding episodes, and decreased hemoglobin concentration (mean reduction 1.1 g/dl). Standard measures of scleroderma were unchanged, although global assessment favored relaxin over placebo.

CONCLUSION

Recombinant human relaxin in the doses used was safe and well tolerated. Longer term controlled trials are warranted to define the potential efficacy of relaxin in patients with diffuse scleroderma.

Sodium regulating hormones at high altitude: basal and post-exercise levels

High altitude (HA)-induced diuresis is associated with marked changes in sodium and water regulating hormones, particularly the renin-angiotensin-aldosterone system (RAAS) and atrial natriuretic hormone (ANH). These hormones are also strongly stimulated by physical exercise, which is a major component of daily activity at HA. In spite of the numerous studies in literature, a clear relationship between hormonal changes, HA diuresis, and physical exercise has not yet been established. We therefore evaluated the response of sodium regulating hormones to exhaustive exercise in a group of seven males exposed to prolonged HA hypoxia. The study was divided into four phases: sea level (SL1), after 7 (P1) and after 21 (P2) days at 5050 m (Italian National Research Council Pyramid Laboratory, Nepal), and back at sea level (SL2). At each phase plasma hematocrit (Ht), total body water (TBW), 24-hr sodium excretion (uNa), and urinary volume (uV) were evaluated together with PRA, plasma aldosterone, and ANH, in samples drawn basally from patients in upright position, and at the end of graded step-wise (30 W/2 min) maximal exercise. Levels of uNa and uV were raised at P1 and then declined at P2, with a parallel decrease in TBW and an increase in Ht. Basal PRA and aldosterone levels were suppressed both at P1 and P2 (from 1.9 +/- 0.4 to 0.08 +/- 0.03 and 0.5 +/- 0.1 ng/mL/3 h, and from 7.9 +/- 1.8 to 3.9 +/- 0.4 and 4.5 +/- 0.4 ng/dL, respectively; P < .05). Exhaustive exercise at HA did not induce any significant response in PRA and aldosterone, unlike SL1. Otherwise at P1 ANH levels remained unchanged both basally and during exercise, while at P2 they decreased significantly vs. SL1, both basally and after exercise (from 13.3 +/- 5.7 to 3.5 +/- 1.2 and from 40.2 +/- 10.2 to 17.5 +/- 8.3, respectively; P < .05). Our data show that PRA and aldosterone levels were constantly suppressed at HA and were unresponsive to exercise, whereas the ANH response was significantly stimulated during acute HA exposure, but not during chronic exposure. This suggests that hypoxia-induced chemoreceptor stimulation may cause the natriuretic phenomenon through direct suppression of the RAAS.

Interleukin-6 receptor antagonists inhibit interleukin-11 biological activity

The IL-6 receptor system comprises two functionally different chains: a binding chain (IL-6R) and a signal-transducing chain (gp130). The IL-6/IL-6R complexes associate with gp130, induce its dimerization and signal transduction. When IL-6 is complexed to IL-6R, two distinct sites of IL-6 are able to bind gp130. Other cytokines-oncostatin M (OM), leukemia inhibitory factor (LIF) or ciliary neurotrophic factor (CNTF) also use the gp130 transducer and induce its heterodimerization with LIF receptor (LIFR). A series of IL-6 mutants have been generated which function as IL-6 receptor antagonists (IL-6RA). These IL-6RA carried substitutions that increased their affinity with IL-6R and abolished 1 or the 2 sites of interaction with gp130. All the IL-6RA inhibited wild-type IL-6. The IL-6RA with one mutated binding site to gp130 inhibited IL-11 activity. They did not affect those of CNTF, LIF and OM, even when used at a very high concentration at which virtually all membrane IL-6R were bound to IL-6RA. IL-6RA with two mutated gp130 binding sites did not affect IL-11, CNTF, LIF or OM activities. The results indicate that the interaction of one gp130 chain with IL-6R/IL-6R complexes inhibited further the dimerization of gp130 induced by IL-11/IL-11R but not its heterodimerization with LIFR. Thus these IL-6RA can also function as IL-11 antagonists.

Angiotensin II receptors in cortical and medullary adrenal tumors

Several pieces of evidences suggest that angiotensin II (Ang II) has mitogenic effects, and a link between Ang II receptors and adrenal tumors can be suggested. In various adrenal tumors, aldosterone-producing adenoma (APA), Cushing's adrenal adenomas (Cush), pheochromocytomas (Pheo), and adrenal carcinomas, we studied the density, affinity, and subtype of Ang II receptors. Ang II binding was tested in cell membrane homogenates. [125I]Ang II was used as ligand, and Losartan and CGP 42112 were used as selective Ang II type 1 and type 2 antagonists, respectively. In APA, Ang II receptor density was 178.5 +/- 82.7 fmol/mg: however, due to the high degree of variability, the receptor density was not significantly higher than that in nontumorous adrenal cortex (59.3 +/- 8.4 fmol/mg). In Cush, the receptor density (27.6 +/- 8.2 fmol/mg; P < 0.05) was significantly lower than that in controls, whereas in Pheo and cortical carcinoma, Ang II binding was very low and in several cases almost undetectable. There was no remarkable difference in the Ang II receptor affinity among all tissues tested. The ratio between type 1 and type 2 Ang II receptors showed a large prevalence of type 1 in controls, APA, and three cases of Cush; in two cases of Cush, this ratio was reversed. In conclusion, our data indicate that Ang II receptors are normally expressed in APA and can also be detected in Cush, whereas they have a very low density in Pheo and adrenal carcinoma. Therefore, Ang II receptors are not involved in the lack of response to Ang II that is characteristic of APA; additionally, a reduction of Ang II receptors can be associated with dedifferentiation or malignancy of adrenal tumors. Further investigation of the expression and functional characterization of Ang II receptors is required to better clarify their possible role in adrenal tumorigenesis.

Combined treatment with amphotericin-B and granulocyte transfusion from G-CSF-stimulated donors in an aplastic patient with invasive aspergillosis undergoing bone marrow transplantation

Granulocyte transfusions from G-CSF stimulated donors were added to standard anti-infective treatment in preparation for and during allogeneic bone marrow transplantation in a young man affected by very severe acute aplastic anemia and invasive aspergillosis. Nine concentrates with a mean neutrophil content of 18.7 x 10(9)/L (2.6 x 10(8)/kg patient b.w.) were transfused before and after marrow infusion. An impressive clinical improvement was noticed after each granulocyte transfusion, although this was not always paralleled by a neutrophil increase in the peripheral blood. Engraftment (N > 0.5 x 10(9)/L and Plt > 25 x 10(9)/L) was verified at +16 and +40 days, respectively. The patient is currently in complete hematological and microbiological remission 14 months after transplantation. Granulocyte apheresis from G-CSF stimulated donors provides a high number of activated neutrophils. At the dose given (300 micrograms/day) donor tolerance to G-CSF was excellent. This new approach is indicated when life-threatening infections develop in patients exposed to prolonged severe neutropenia.

Echo Doppler color flow (EDCF) evaluation of vascular pathology in pediatric age groups

Although rarely observed, vascular diseases in children constitute a complex clinical problem. Until recently the diagnostic approach to infant vascular diseases was based on invasive methods such as arteriography, but now the use of ultrasonographic methods such as Doppler c.w. and Echo Doppler Color Flow (EDCF) in angiology can offer new and interesting application even in the pediatric age range. In the present study 15 children affected by vascular diseases (eight with arteriovenous fistulas (AVF), two with pseudoaneurysms, and five with angiomas or cysts) either of iatrogenic or congenital etiology, were examined by Doppler c.w. and EDCF. In three additional cases a suspected vascular disease was not confirmed. The data obtained by Doppler c.w. and EDCF proved useful to perform a preoperative diagnosis; however some diagnostic criteria differed from those described in adulthood, as in the AVF cases, for instance, we observed the prevalence of indirect signs such as alterations of venous flow, and the presence of "multicolored speckled mass" and of "the spreading of the color in extravasal space" rather than a direct connection between an artery and a vein. Also pseudoaneurysms were easily detected by EDCF. In two cases of congenital AVF, the diagnosis was confirmed by arteriography. Surgery was performed in 9 children, 7 with AVF and 2 with pseudoaneurysm; in all cases, the vascular defect detected by ultrasonography was visualized and corrected. In 7 cases EDCF was also used in the follow-up. In conclusion this study suggests a possible more extensive use of ultrasonographic methods in the diagnostic approach to vascular diseases in pediatric age groups, and points out their validity in screening very young patients and in their surgical follow-up.

Blood cell flow cytometry in paroxysmal nocturnal hemoglobinuria: a tool for measuring the extent of the PNH clone

The membrane expression of nine glycosyl phosphatidyl inositol (GPI)-linked molecules was analyzed by flow cytometry on circulating cells from 18 patients affected by paroxysmal nocturnal hemoglobinuria (PNH). The results allowed us to select CD66b, CD14, CD59, CD24 and CD59 monoclonal antibodies as the most suitable reagents for discriminating between normal and PNH cells in PMN, monocytes, RBC and B or T lymphocytes, respectively. In order to assess whether the analysis of distinct cell populations could provide differential information on the extent of the disease, we compared the proportion of residual normal cells in RBC, monocyte and PMN populations. The mean percentage of unaffected cells was higher in RBC as compared to PMN (50.5 +/- 18.7 vs 17.7 +/- 19.7, P < 0.0001). The proportion of normal PMN was, in turn, significantly greater than that of normal monocytes (17.7 +/- 19.7 vs 8.7 +/- 11.0; P < 0.05). The percentage of CD14+ monocytes was directly related to Hb concentration and platelet (Plt) count, and inversely to percent lysis at the Ham's test. The percentage of CD66b+ PMN was directly related to Plt count and Hb level, while the percentage of CD59+ RBC was associated, in an inverse fashion, only to the Ham's test. No significant correlation was found between cell marker expression and PMN count, reticulocytosis, bilirubin and serum LDH. By dividing the patients into two groups, according to high (> 10 percent) or low (< 10 percent) percentage of CD14+ monocytes, a statistical analysis showed that the main hematological parameters were significantly different.

Two different dosages of yeast derived recombinant hepatitis B vaccines: a comparison of immunogenicity

The efficacy of a 10 or 20 micrograms antigen load of HB recombinant vaccines is still being debated. A comparison of anti-HBs titres in two groups of healthy subjects vaccinated by the same schedule (0, 1 and 6 months) employing recombinant HB vaccines with different antigen loads, 20 micrograms (group A, 251 subjects) and 10 micrograms (group B, 256 subjects) was carried out. A seroprotection rate of 99.6 and 99.2% was observed for group A and group B, respectively, at the end of primary immunization. No statistically significant difference in seroprotection rate was observed. Group A showed significantly higher GMTs than group B for all age groups and for both sexes except for males above 25 years. The difference was more marked for younger age groups and for the female sex. These data support the higher immunogenicity of vaccine with 20 micrograms antigen load as compared to vaccines with 10 micrograms antigen load.

Bacterial lipopolysaccharide stimulates glucocorticoid secretion in hypophysectomized rats

The effect of an i.p. bolus injection of 200 micrograms.kg-1 bacterial lipopolysaccharide (LPS) on the plasma concentrations of ACTH and corticosterone (B) were studied in intact and hypophysectomized/ACTH replaced (Hx) rats. Hormonal blood levels were measured by RIA, 30, 60, 120, 180 and 240 min after the injection. The stress evoked by the vehicle i.p. injection provoked significant rises in ACTH and B blood levels at 30 and 60 min in intact rats, but not in Hx animals. In intact rats, LPS enhanced (over the respective control value) ACTH plasma level at 60, 120 and 180 min, and B plasma concentration at 120, 180 and 240 min. In Hx rats, LPS did not affect ACTH blood level, but raised B plasma concentration at 60, 120 and 180 min. B response to LPS at 120 min was completely annulled, in both intact and Hx rats, by the simultaneous administration of 25 nmol.kg-1 alpha-helical-CRH and corticotropin-inhibiting peptide that are competitive inhibitors of CRH and ACTH, respectively. The hypothesis is advanced that LPS may activate hypothalamo-pituitary adrenal axis in rats, by stimulating not only the central (hypothalamo-pituitary), but also the peripheral (intra-adrenal) branch of the CRH/ACTH system.