Human and monkey fetal brain development of the supramammillary-hippocampal projections: a system involved in the regulation of theta activity

The supramammillary (SUM)-hippocampal pathway plays a central role in the regulation of theta rhythm frequency. We followed its prenatal development in eight Cynomolgus monkeys (Macaca fascicularis) from embryonic day E88 to postnatal day 12 (term 165 days) and in eight human fetuses from 17.5 to 40 gestational weeks, relying on neurochemical criteria established in the adult (Nitsch and Leranth [1993] Neuroscience 55:797-812). We found that 1) SUM afferents reached the dentate juxtagranular and CA2 pyramidal cell layers at midgestation in human fetuses, earlier than in monkeys (two-thirds of gestation [E109]). They co-expressed calretinin, substance P, and acetylcholinesterase but not gamma-aminobutyric acid (GABA) or glutamic acid decarboxylase (GAD); 2) the presumed parent neurons in the monkey SUM expressed calretinin or both calretinin and substance P; 3) most of them were surrounded by GAD-containing terminals that might correspond to the septo-SUM feedback pathway (Leranth et al. [1999] Neuroscience 88:701); and 4) in addition, a large band of calretinin-labeled terminals that did not co-express substance P, GAD, or acetylcholinesterase was present in the deepest one-third of the dentate molecular layer in both the Cynomolgus monkey and human fetuses. It persisted in the adult monkey but not in adult human hippocampus; it remains questionable whether it originates in the SUM. In conclusion, the early ingrowth of the excitatory SUM-hippocampal system in human and non-human primates may contribute to the prenatal activity-dependent development of the hippocampal formation. The possibility and the functional importance of an in utero generation of hippocampal theta-like activity should also be considered.

Comparative study of a portable prothrombin time monitor employing three different systems in oral anticoagulant units

The aim of this study was to evaluate the accuracy of the portable coagulometer CoaguChek (Roche Diagnostics) as a prothrombin time (PT) monitor, and to correlate capillary blood results with those of three different routine methods used for monitoring oral anticoagulant therapy (OAT): capillary, plasma and whole blood samples. Three hospitals participated in the study with a total of 235 patients on OAT. The international normalized ratio (INR) results obtained with CoaguChek were compared with those obtained using each of the routine methods. The study presents a good correlation between the PT monitor and the three methods studied: r = 0.9745 (hospital A), r = 0.9283 (hospital B), r = 0.9136 (hospital C). A simplified concordance test of the methods results in a nine-field comparison table showing concordances of 87.2, 85.7 and 68.4%, respectively. The absolute difference (mean +/- SD) between laboratory A and CoaguChek INRs was 0.0571 +/- 0.2042, with values of 0.04286 +/- 0.3906 for laboratory B and 0.6986 +/- 0.6170 for laboratory C. These results confirm that CoaguChek could be used as a new method for oral anticoagulant monitoring, and is in best agreement with the capillary blood PT system.

Effects of experimental diabetes on renal IGF/IGFBP system during neonatal period in the rat

Changes in the renal synthesis and concentration of insulin-like growth factors (IGFs) and their serum-binding proteins (IGFBPs) reported in insulin-deficient diabetes mellitus may be implicated in the alterations of the kidney function and morphology accompanying this disease. Most research on this subject has been carried out in adult animals, as well as in peripubertal rats, when the regulation of the IGF system is fully dependent on serum growth hormone (GH). However, relevant differences in the regulatory pathways of IGFs between adult and neonatal periods have been described. To examine the response of the IGF/IGFBP system of neonatal kidney to diabetes, renal IGF-I and -II and IGFBP-1, -2, and -3 concentration and mRNA expression were determined in streptozotocin-induced diabetic rat neonates. Diabetic neonates exhibited a kidney weight-to-body weight ratio higher than that of control rats, together with decreased IGF-I and increased IGF-II renal concentration. Because kidney mRNA expression of both IGFs decreased, the elevated renal IGF-II might result from increased uptake from circulation. Insulin treatment recovered the altered IGFs to control values, indicating the insulin-dependent regulation of IGFs in the neonatal kidney. Elevated levels of the IGFBP-1 and -2 in the kidney of diabetic neonates did not result from changes in their kidney mRNA transcript expression, suggesting also a possible uptake from circulation.

Losartan, a selective inhibitor of subtype AT1 receptors for angiotensin II, inhibits neutrophil recruitment in the lung triggered by fMLP

We have shown that losartan, a selective inhibitor of AT1 receptors for angiotensin II (AII), inhibits the binding of [3H]fMLP to neutrophil receptors (FPR). Here, we analyze, in Wistar rats, the effect of losartan on neutrophil recruitment in the lung triggered by fMLP. We found that i.v. infusion of losartan (0.4-20.0 microg/kg/min) inhibits neutrophil recruitment induced by i.t. instillation of fMLP, without affecting the responses induced by other stimuli, such as aggregated human IgG (aIgG), precipitating immune complexes (IC), or zymosan. Histological evaluation of lungs as well as the analysis of lung hemorrhage indices showed that losartan prevents tissue injury partially in fMLP-challenged rats. We also analyzed the effect of losartan on lung-neutrophil recruitment triggered by i.t. instillation of Pseudomonas aeruginosa. Not only was there a marked decrease in neutrophil recruitment but also a significant increase in the survival of rats instillated with Pseudomonas aeruginosa, as a consequence of losartan treatment. Our results support the notion that losartan may be useful in the treatment of certain lung inflammatory disorders associated with bacterial infectious diseases.

A DNA polymorphism at the alpha2-macroglobulin gene is associated with the severity of rheumatoid arthritis

OBJECTIVE

To determine if DNA polymorphisms at the alpha2-macroglobulin (alpha2m) and angiotensin converting enzyme (ACE) genes were associated with rheumatoid arthritis (RA).

METHODS

A total of 160 patients (71 with early active severe RA, 89 with non-severe RA) were genotyped (polymerase chain reaction) for the alpha2m (5 bp deletion/insertion) and ACE (I/D) polymorphisms. We also genotyped 500 healthy controls from the same Caucasian population (Asturias, Northern Spain).

RESULTS

Carriers of the alpha2m deletion allele were at a significantly higher frequency among patients with an early active severe form of the disease, compared to patients with non-severe RA (p = 0.037). The frequency of the alpha2m deletion allele was significantly higher in patients with severe compared to nonsevere RA (p = 0.017). In addition, the frequency of the deletion allele was significantly higher among patients with 5 or more episodes of acute exacerbation of disease activity per year (n = 39) compared to those with none (n = 46) (p = 0.002). Gene and genotype frequencies for the ACE-I/D polymorphism did not differ between those with early active severe and non-severe RA.

CONCLUSION

The genetic variation at alpha2m is associated with the severity of RA. Carriers of the alpha2m deletion allele would have increased risk of developing an early active severe form of the disease. Our data suggest that alpha2m could be a valuable target in the treatment of RA.

The origin of the Jingwei gene and the complex modular structure of its parental gene, yellow emperor, in Drosophila melanogaster

Jingwei (jgw) is the first gene found to be of sufficiently recent origin in Drosophila to offer insights into the origin of a gene. While its chimerical gene structure was partially resolved as including a retrosequence of alcohol dehydrogenase (ADH:), the structure of its non-ADH: parental gene, the donor of the N-terminal domain of jgw, is unclear. We characterized this non-ADH: parental locus, yellow emperor (ymp), by cloning it, mapping it onto the polytene chromosomes, sequencing the entire locus, and examining its expression patterns in Drosophila melanogaster. We show that ymp is located in the 96-E region; the N-terminal domain of ymp has donated the non-ADH: portion of jgw via a duplication. The similar 5' portions of the gene and its regulatory sequences give rise to similar testis-specific expression patterns in ymp and jgw in Drosophila teissieri. Furthermore, between-species comparison of ymp revealed purifying selection in the protein sequence, suggesting a functional constraint in ymp. While the structure of ymp provides clear information for the molecular origin of the new gene jgw, it unexpectedly casts a new light on the concept of genes. We found, for the first time, that the single locus of the ymp gene encompasses three major molecular mechanisms determining structure of eukaryotic genes: (1) the 5' exons of ymp are involved in an exon-shuffling event that has created the portion recruited by jgw; (2) using alternative cleavage sites and alternative splicing sites, the 3' exon groups of ymp produce two proteins with nonhomologous C-terminal domains, both exclusively in the testis; and (3) in the opposite strand of the third intron of ymp is an essential gene, musashi (msi), which encodes an RNA-binding protein. The composite gene structure of ymp manifests the complexity of the gene concept, which should be considered in genomic research, e.g., gene finding.

Modification of acquired immunity in BALB/c mice by aztreonam

Recent studies have suggested that antibiotics may act as biological response modifiers. In this study we investigated the effect of aztreonam, a monobactam antibiotic, on different parameters of acquired immunity in BALB/c mice. Different dosages of aztreonam injected into mice induced an increase in the lymphoproliferative response to specific mitogens and in the production of interleukin-2 by splenic cells, as well as a decreased response of this immune population to sheep erythrocytes lower total blood cell counts and a lower percentage of monocytes than in untreated mice. These results show a modulatory action of aztreonam on different immune parameters, which is independent of its antimicrobial activity and that could be of interest in human therapy.

Technique and early results of outpatient laparoscopic mesh onlay repair of ventral hernias

BACKGROUND

This report describes the technique and early results of a simple outpatient laparoscopic ventral hernia repair.

METHODS

Data were gathered prospectively for all laparoscopic ventral hernia repairs from January 1996 to December 1997 at a 228-bed hospital. Prolene mesh was stapled to the peritoneal surface of the abdominal wall, leaving sac in situ and mesh uncovered. Patients were seen by the operating surgeon within 2 months, and by an impartial surgeon (J.S.) after 3 to 14 months (average, 7 months; median, 6 months).

RESULTS

Repairs involved 44 hernias with orifice sizes 2 to 20 cm in diameter, and an average area of 20 cm(2). Of these 44 hernias, 36 were postoperative and 8 primary. Furthermore, 20% were recurrent hernias. There were four conversions. The outpatient rate was 98%, with one readmission for ileus. The early recurrence rate was 5%.

CONCLUSIONS

Laparoscopic mesh onlay repair is a safe, easy, and effective procedure with minimal discomfort and a low early recurrence rate that can be performed safely on an outpatient basis.

Effect of early dietary restriction on insulin action and secretion in the GK rat, a spontaneous model of NIDDM

The availability of the Goto-Kakisaki (GK) rat model of non-insulin-dependent diabetes mellitus prompted us to test the effect of a limited period of undernutrition in previously diabetic young rats on their insulin secretion and insulin action during adult age. Four-week-old female GK rats were either food restricted (35% restriction, 15% protein diet) or protein and energy restricted (35% restriction, 5% protein diet) for 4 wk. Food restriction in the young GK rat lowered weight gain but did not aggravate basal hyperglycemia or glucose intolerance, despite a decrease in basal plasma insulin level. Furthermore, the insulin-mediated glucose uptake by peripheral tissues in the GK rat was clearly improved. We also found that food restriction, when it is coupled to overt protein deficiency in the young GK rat, altered weight gain more severely and slightly decreased basal hyperglycemia but conversely aggravated glucose tolerance. Improvement of basal hyperglycemia was related to repression of basal hepatic glucose hyperproduction, despite profound attenuation of basal plasma insulin level. Deterioration of tolerance to glucose was related to severe blunting of the residual glucose-induced insulin secretion. It is, however, likely that the important enhancement of the insulin-mediated glucose uptake helped to limit the deterioration of glucose tolerance.

Complicated enterocutaneous fistulas: failure of octreotide to improve healing

Octreotide has been promoted as a potential aid during closure of enterocutaneous fistulas (ECFs) on the basis of clinical and experimental evidence that it can reduce gastrointestinal secretions. We retrospectively reviewed the records of patients admitted with ECF to our tertiary referral center to ascertain whether use of octreotide affected fistula duration, length of hospitalization, closure rate, and morbidity. Of 60 patients diagnosed and treated for ECF over a 4-year period, 13 underwent a therapeutic trial with octreotide. Thirteen patients from the group who did not receive octreotide were matched by cause, location, and output of the fistula, age, and primary diagnosis to the treatment group. Octreotide was administered in therapeutic dosage for a mean course of 57 +/- 29 days, resulting in a substantial acute decrease (84.7 +/- 4.8%) in fistula output. Prolonged therapy nevertheless failed to affect the outcome parameters studied, particularly fistula duration, spontaneous closure rate, and length of hospitalization. There was a significantly higher incidence of septic and thrombotic complications associated with octreotide use. In this patient population with complicated ECFs, use of octreotide showed no benefit and was associated with increased morbidity.

Higher levels of serum copper in schizophrenic patients treated with depot neuroleptics

The findings of previous research on the status of trace elements in patients with schizophrenia have been controversial. We studied 62 outpatients with a DSM-IV diagnosis of schizophrenia, and compared them with sex- and age-matched healthy controls. Serum copper levels were significantly higher in schizophrenic patients (mean 117.4 microg/dl; S.D. 23.4) than in healthy controls (105.6+/-27.9). Those patients on treatment with depot neuroleptics had higher copper levels. Zinc levels did not differ between patients and healthy controls. Altered levels of trace elements in schizophrenic patients may be a consequence of antipsychotic treatment.

Prevalence of genotypic resistance to nucleoside analogues and protease inhibitors in Spain. The ERASE-2 Study Group

OBJECTIVE

To examine the prevalence of resistance mutations to nucleoside reverse transcriptase inhibitors (NRTI) and protease inhibitors (PI) in a representative HIV-1 population in Spain.

METHODS

A cross-sectional study was conducted including 601 HIV-infected patients who attended 20 Spanish hospitals in June 1998. Drug resistant mutations were examined using hybridization line probe assays (LiPA). The 6 bp insert at position 69 and the codon 75 mutant were examined by sequencing analysis in specimens lacking reactivity to 69/70 and 74 bands on LiPA, respectively.

RESULTS

Primary resistance to NRTI was recognized in nine out of 52 (17%) naive individuals, whereas primary resistance to PI was found in seven out of 126 (6%) PI-naïve patients. The codons most frequently involved in NRTI resistance were at positions 70 (66%), 184 (44%), 215 (33%), and 41 (11%), whereas the most common PI resistance mutation was at codon 82 (6/7 subjects). In pre-treated patients, the overall prevalence of resistant genotypes was 72.9% for NRTI and 27.2% for PI. The most frequent NRTI mutations occurred at codons 184 (38.5%), 215 (30.1%), and 41 (22.5%), whereas the most frequent PI mutations in pre-treated subjects were found at positions 82 (15.8%) and 84 (11.4%). Overall, patients who began triple combinations as initial therapy showed a lower number of key resistance mutations than those who began highly active antiretroviral therapy (HAART) after being exposed to NRTI for a period of time (mean number of mutations, 0.1 versus 1.8, P< 0.05). Codon 75 mutant was found in three out of 387 patients (0.7%), whereas no insertions at codon 69 were recognized.

CONCLUSION

The prevalence of primary genotypic resistance to NRTI and PI in Spain was 17% and 6%, respectively. Zidovudine, lamivudine, indinavir and ritonavir were the drugs most frequently affected. These data support the use of resistance testing prior to the introduction of first-line antiretroviral therapies in Spain. Among pre-treated subjects, drug resistance genotypes were less prevalent in those who began HAART as initial therapy.

The membrane transport factor p115 recycles only between homologous compartments in intact heterokaryons

Cytosolic proteins that participate in membrane traffic are assumed to be recruited from the cytosol onto specific membrane sites where they perform their function, and then released into cytosol before rebinding to catalyze another round of transport. To examine whether the ER to Golgi transport factor p115 recycles through release into a cytosolic pool, we formed heterokaryons between rat NRK and simian COS-7 cells and examined the dynamics of rat p115 transfer from the rat to the simian portion of the heterokaryon. The heterokaryons shared a common cytosolic pool, as shown by the efficient relocation of a cytosolic green fluorescent protein (GFP) from the COS-7 to the NRK part of the heterokaryon. Unexpectedly, even 24 h after cell fusion, rat p115 did not redistribute to the COS-7 part of the heterokaryon. This was not due to the inability of the rat p115 to associate with simian membranes since rat p115 expressed in COS-7 cells was efficiently targeted to and associated with simian Golgi complex. Furthermore, rat p115 associated with heterologous simian membranes after the NRK and COS-7 Golgi fused into a single chimeric structure. Our results indicate that p115 is not freely diffusible in intact cells and might remain tethered to membranes throughout its life cycle. These findings suggest that p115, and perhaps other cytosolic proteins involved in membrane traffic, recycle not by being released into cytosol, but in association with recycling membranes.

Cellular activity of murine phagocytes isolated from peripheral blood by a discontinuous gradient

A mixture of Ficoll 400 and sodium diatrizoate (Hypaque) at a density of 1.077 g/ml has been used to isolate the mononuclear cells from the remaining haematic cells. A simple, inexpensive and classical method was established to obtain substantially erythrocyte-free polymorphonuclear cell preparations from mouse peripheral blood, using a mixture of the same substances but at a density of 1.119 g/ml. This method along with that at a density of 1.077 g/ml allows two cellular bands to appear which contain mononuclear and polymorphonuclear (PMN) cells, respectively. Using this method, the counts of monocytes isolated from peripheral blood are significantly greater than those obtained by a one-step Ficoll-Hypaque procedure. On the contrary, the counts of PMN cells are significantly smaller than when sedimentation in dextran (6% solution) is used after gradient centrifugation. In this paper, chemiluminescence assay has been used to analyze the possible variations in phagocytic activity of cells isolated by both procedures, since it appears to be one of the most sensitive methods available for this purpose. The results obtained show a slightly greater activation in monocytes and PMN cells isolated by one-step Ficoll-Hypaque procedure, in comparison with another method which uses both Ficoll-Hypaque 1077 and Ficoll-Hypaque 1119, although statistical differences were not significant.

The road to ambulatory laparoscopic management of perforated appendicitis

BACKGROUND

This study examines the contribution of increased laparoscopic skills to ambulatory management of perforated appendicitis.

METHODS

All 38 perforated appendicitides from 151 laparoscopic appendectomies done by one surgeon were studied and ambulatory management (discharge less than 24 hours after surgery) of the last 18 perforations reported.

RESULTS

Over 4 years, rate of attempted laparoscopic appendectomy rose from 67% to 100% for perforations. Conversion rate fell from 100% to 22%. Ileus and pain control were not problems for most laparoscopic perforations, so by the end of 1997, experience suggested these patients might be discharged within 24 hours. Ambulatory rate was 57% (conversions excluded). There were no readmissions for wound infections or postoperative abdominal abscesses.

CONCLUSIONS

Increasing laparoscopic skills allows laparoscopic treatment of complicated appendicitis with a low conversion rate and no infectious complications. Over one half of these patients can be managed as outpatients without jeopardy to outcome.

A modified AIDA protocol with anthracycline-based consolidation results in high antileukemic efficacy and reduced toxicity in newly diagnosed PML/RARalpha-positive acute promyelocytic leukemia. PETHEMA group

The Spanish PETHEMA group designed a protocol for newly diagnosed PML/RARalpha-positive acute promyelocytic leukemia (APL) in which induction and consolidation followed the original AIDA regimen, except for the omission of cytarabine and etoposide from consolidation. Induction consisted of 45 mg/m(2) all-trans retinoic acid (ATRA) daily until complete remission (CR) and 12 mg/m(2) idarubicin on days 2, 4, 6, and 8. Patients in CR received 3 monthly chemotherapy courses: idarubicin 5 mg/m(2)/d x 4 (course no. 1), mitoxantrone 10 mg/m(2)/d x 5 (course no. 2), and idarubicin 12 mg/m(2)/d x 1 (course no. 3). Maintenance therapy consisted of 90 mg/m(2)/d mercaptopurine orally, 15 mg/m(2)/wk methotrexate intramuscularly, and, intermittently, 45 mg/m(2)/d ATRA for 15 days every 3 months. Between November 1996 and December 1998, 123 patients with newly diagnosed PML/RARalpha-positive APL from 39 centers were enrolled. A total of 109 patients achieved CR (89%; 95% confidence interval [CI], 83 to 95), 12 died of early complications, and the remaining 2 were resistant. Consolidation treatment was associated with very low toxicity and no deaths in remission were recorded. Molecular assessment of response by reverse transcriptase-polymerase chain reaction (RT-PCR) showed conversion to PCR-negative in 48 of 99 (51%) and 82 of 88 patients (93%) after induction and consolidation, respectively. The 2-year Kaplan-Meier estimates of overall survival and event-free survival were 82% +/- 4% and 79% +/- 4%, respectively. For patients who achieved CR, the 2-year disease-free survival (DFS) was 92% +/- 3%. These data indicate that a significant reduction in toxicity might be obtained in APL using a less intensive consolidation without apparently compromising the antileukemic effect. These results also suggest a minor role for cytarabine and etoposide in the treatment of newly diagnosed PML/RARalpha-positive APL patients.

Cell proliferation activity and kinetic profile in the prognosis and therapeutic management of carcinoma of the pharynx and larynx

Prognosis and management of carcinoma of the pharynx and larynx is now based on the morphologic analysis of the tumor spreading, differentiation grading, and type of microscopic invasion. The DNA ploidy status and the cell proliferation activity analyzed by flow cytometry give us complementary information about the prognosis and the management and support of the patients. We performed a study of 91 cases of carcinoma of the larynx and pharynx by means of flow cytometry. Forty-three patients were treated by surgery alone, and 48 patients also received radiotherapy. Fifty-five were aneuploid (60%); this percentage increased to 74% in the pharynx area and fell to 47% at the larynx level. The aneuploid tumors showed worse behavior in the patients treated by surgery alone compared with those who also received radiotherapy. The S-phase fraction was high in aneuploid tumors, in positive lymph nodes, and in advanced stages. The S-phase fraction was higher in poorly differentiated tumors. In patients treated by surgery alone, we noticed that by combining both cytometric variables two different kinetic profiles could be defined related to the patients' behavior. The diploid tumors with a low S phase had the greatest rates of survival, whereas diploid tumors with a high rate of S phase and aneuploids had a lower rate.

Modification of acquired immunity in mice by imipenem/cilastatin

The immunomodulating properties of antimicrobial drugs may have important implications for clinical practice, particularly for those patients whose immune system has been compromised. In this study, we assessed the influence of different treatments with a beta-lactam antibiotic (imipenem/cilastatin) on several acquired immune responses of BALB/c mice; splenocyte responses to specific mitogens and to sheep red blood cells, IL-2 production and proportions of the different lympho-monocytic populations. Impenem/cilastatin was shown to modify some lymphocyte-associated immune functions and it would be useful to investigate whether immunomodulatory effects also occur in humans.

Histological characteristics of the intestinal mucosa of the rat during the first year of life

In spite of the widespread use of rats in gastrointestinal research, there is a lack of information on the qualitative and quantitative histological characteristics. Therefore, a study was performed in 69 male Wistar rats with ages ranging from one day to one year old. The features studied included: height and number of villi in the duodenum, jejunum and ileum, and depth and number of crypts in the duodenum, jejunum, ileum, colon and rectum. Morphometric observations were expressed in a mathematical logarithmic curve that showed a normal, pattern of intestinal growth for each intestinal level. The number of villi in the small intestine decreased from 1 to 35 days of age, whereas the other intestinal parameters all increased during the same period. After 35 days the rates of increase or decrease were lower. The quantification of these intestinal changes provides a new complementary pattern as a reference for research as indicators of normality or malfunction in the rat intestine.

Stereoselective drug release from ketoprofen and ricobendazole matrix tablets

Crystalline characteristics of racemic, pure R and S enantiomers and physical mixtures of Ketoprofen (KET) have been studied by DSC and X-ray diffractometry. Aqueous solubilities were 182.6 +/- 9.1 microg/ml for racemic KET, 259.6 +/- 6.6 microg/ml for R-KET, and 304.3 +/- 2.7 microg/ml for S-KET. Matrix tablets made with racemic and physical mixtures of KET show stereoselective drug release, which is faster for S-KET than for R-KET. This effect is more marked when the chiral excipient hydroxypropylmethylcellulose (HPMC) is used in place of the achiral Eudragit RL. Stereoselectivity of release is also affected by the amount of KET. Similar results were obtained when another chiral drug with low solubility, Ricobendazole (RBZ), is used. Depending on the excipient and drug dosage, more or less marked stereoselective drug release is obtained in RBZ matrix tablet formulations.

Evaluation of cytokine production and phagocytic activity in mice infected with Campylobacter jejuni

The effect of several Campylobacter jejuni strains on the immune response was analyzed in mice after intraperitoneal inoculation with 10(10) colony forming units (CFU). Three C. jejuni strains were assayed: CCUG 6968 (enterotoxigenic), CCUG 7580 (enterotoxigenic), and CCUG 7440 (non-enterotoxigenic). These C. jejuni strains induced a peritoneal inflammatory response and an important increase in the peritoneal phagocyte oxidative activity measured by chemiluminescence assay, as well as an increase in the number of peritoneal cells. Both interleukin-1 (IL-1) and tumor necrosis factor alpha (TNFalpha) production by peritoneal cells were not modified. However, C. jejuni 7440 caused a statistically significant increase in TNFalpha production. These results have demonstrated that different strains of C. jejuni induce an increase of the inflammatory response without a significant cytokine release. However, these infectious microorganisms may be eliminated efficiently by murine macrophages after phagocytosis.

Effects of aztreonam on natural immunity in mice

The influence of the dose and the duration of treatment with aztreonam, a monocyclic beta-lactam antibiotic, on the natural immune response of mice has been investigated. The results show the effects induced by the antibiotic on several immune parameters were affected by the duration of treatment. Thus, treatment with 28 mg/kg per day of aztreonam over 14 days increased every immune parameter tested, while treatment with 57 mg/kg per day of aztreonam for 7 days only enhanced the natural killer (NK) activity of splenocytes. Since aztreonam does not apparently impair the innate immune response, it might be a suitable therapy for the treatment of patients who are immunosuppressed.