Biodegradable Electrospun Conduit with Aligned Fibers Based on Poly(lactic-co-glycolic Acid) (PLGA)/Carbon Nanotubes and Choline Bitartrate Ionic Liquid

Functionally active aligned fibers are a promising approach to enhance neuro adhesion and guide the extension of neurons for peripheral nerve regeneration. Therefore, the present study developed poly(lactic-co-glycolic acid) (PLGA)-aligned electrospun mats and investigated the synergic effect with carbon nanotubes (CNTs) and Choline Bitartrate ionic liquid (Bio-IL) on PLGA fibers. Morphology, thermal, and mechanical performances were determined as well as the hydrolytic degradation and the cytotoxicity. Results revealed that electrospun mats are composed of highly aligned fibers, and CNTs were aligned and homogeneously distributed into the fibers. Bio-IL changed thermal transition behavior, reduced glass transition temperature (Tg), and favored crystal phase formation. The mechanical properties increased in the presence of CNTs and slightly decreased in the presence of the Bio-IL. The results demonstrated a decrease in the degradation rate in the presence of CNTs, whereas the use of Bio-IL led to an increase in the degradation rate. Cytotoxicity results showed that all the electrospun mats display metabolic activity above 70%, which demonstrates that they are biocompatible. Moreover, superior biocompatibility was observed for the electrospun containing Bio-IL combined with higher amounts of CNTs, showing a high potential to be used in nerve tissue engineering.

Epoxidized Ionic Liquids as Processing Auxiliaries of Poly(Lactic Acid) Matrix: Influence on the Manufacture, Structural and Physical Properties

In this study, we set out to modify poly(lactic acid) (PLA) by incorporating epoxidized ionic liquids (ILs) that were specifically designed with imidazolium-NTf₂ moieties. First, we synthesized di-, tri- and tetra-epoxidized ILs, which were incorporated into a PLA matrix at 3, 5, and 10 wt% through a melt extrusion process. We investigated the relationship between the structure and properties of the resulting materials in terms of thermal, mechanical, rheological, and surface properties. The results showed the potential of ILs to impact these properties. Notably, the tri- and tetra-epoxidized ILs enhanced the thermal stability of the PLA matrix as well as the crystallinity while reducing the glass transition temperature and melting point, which is promising for reactive extrusion processing. Overall, this research opens new routes for using reactive ILs to improve the processing and properties of PLA polymers.

Aligned electrospun nerve conduits with electrical activity as a strategy for peripheral nerve regeneration

Peripheral nerve injuries affect the quality of life of people worldwide. Despite advances in materials and processing in recent decades, nerve repair remains a challenge. The autograft is considered the most effective nerve repair in cases of serious injuries in which direct suture is not applied. However, the autograft causes the loss of functionality of the donor site, and additionally, there is a limited availability of donor nerves. Nerve conduits emerge as an alternative to the autograft and nowadays some conduits are available for clinical use. Nevertheless, they still need to be optimized for better functional nerve response. This review proposes to analyze the use of aligned electrospun nerve conduits with electrical activity as a strategy to enhance a satisfactory nerve regeneration and functional recovery.

Prophylactic intraoperative uterine artery embolization for the management of major placenta previa

PURPOSE

Placenta previa is a major cause of maternal morbidity and mortality, associated to a high risk of peripartum hemorrhage and hysterectomy. We aimed to verify if prophylactic intraoperative uterine artery embolization in patients with placenta previa and at least one additional risk of bleeding (major placenta previa), can reduce hemorrhage, need for blood transfusions, peripartum hysterectomy and maternal morbidity.

MATERIALS AND METHODS

We enrolled 76 patients with major placenta previa; a specific multidisciplinary protocol was designed for management, including ultrasound evaluation, hospitalization at 34 weeks, antenatal corticosteroids and scheduled cesarean section at 35-36 weeks. 44 patients (control group or CTR) were treated with elective cesarean section, 32 patients (embolized group or EMB) underwent selective catheterization of bilateral uterine arteries before cesarean section and subsequent uterine embolization. In both cases cesarean section was performed by a senior surgeon.

RESULTS

Significant differences were found in term of intraoperative blood loss (CTR: 1431 ml; EMB: 693 ml); despite an high percentage of CTR patients had a bleeding greater than 1000 ml (56%), the need for blood transfusion was not significantly different between the two groups. Time of surgery was higher in the EMB group, considering that embolization procedure required approximatively 30 min. Three patients from the CTR group needed hysterectomy and ICU admission, compared to none in the EMB group. Duration of hospitalization and neonatal outcome were similar. Uterine embolization was not related to any short or long-term complications; return to normal menses and preservation of fertility were confirmed at follow up.

CONCLUSIONS

Our results are promising, although we believe that a major contribution is referable to the multidisciplinary approach rather than the procedure itself. Nevertheless, we demonstrated the feasibility and safety of preventive uterine embolization in patients with placenta previa; in order to establish its prophylactic role in the prevention of peripartum hemorrhage, randomized trial should be carried out, on a larger population.

In vitro evaluation of bilayer membranes of PLGA/hydroxyapatite/β-tricalcium phosphate for guided bone regeneration

Membranes for guided bone regeneration represent valuable resources, preventing fibroblast infiltration and aiding anatomical bone reconstruction. Nonetheless, available membranes lack bone regenerative capacity, suitable mechanical behavior, or adequate degradation profile. Therefore, to overcome these limitations, this study developed bilayer membranes with a dense layer (dry phase inversion) of PLGA (poly(lactic-co-glycolic acid)):HAp (hydroxyapatite) - 95:05 (wt%) - and an electrospun layer of PLGA and HAp:β-TCP (β-tricalcium phosphate) with ratios of 60:40, 70:30 and 85:15 (wt%), evaluating its mechanical, morphological and in vitro properties. The bilayer membranes displayed adequate interlayer adhesion, dense layer pore size of 4.20 μm and electrospun layer with porosity degree of 38.2%, thus capable of preventing fibroblast infiltration while allowing osteoblast migration and nutrient permeation. They also showed T_g of 82 °C and higher storage modulus, which was constant up to 54.6 °C, characteristics important for membrane implantation and use with no mechanical compromise. In vitro degradation mass loss was only 10% after 60 days, a profile suitable for the application requirement. Membranes with calcium phosphates had better osteoblast attachment, proliferation and migration. Taken together, results indicate the great potential of PLGA/HAp/β-TCP bilayer membranes on bone reconstruction with proper degradation profile, morphology, mechanical behavior and bone regenerative capacity.

Manufacturing and characterization of plates for fracture fixation of bone with biocomposites of poly (lactic acid-co-glycolic acid) (PLGA) with calcium phosphates bioceramics

Commercially, there are several plates and screws for bone fracture fixation made with PLA, however, its long degradation time and lack of integration with bone structure, provides interest in research using polymers with faster degradation, such as PLGA, and together with bioceramics, in order to improve bioactivity in bone regeneration. Based on this, in this study, bone fracture fixation plates composed of PLGA polymer matrix and combinations of 5 and 10%wt. of bioceramics were processed by microinjection. The bioceramics used comprehend nanostructured hydroxyapatite (n-HA), β-tricalcium phosphate (β-TCP) and calcium phosphate with ion substitution of magnesium (Mg-Ca/P) and strontium (Sr-Ca/P). The introduction of bioceramics modified thermal and mechanical properties of the polymer. The TGA analysis showed that there was a variation on the ceramic's mass inserted in relation to the expected values (5% and 10%wt.) in all groups of biocomposites. In general, Tg values obtained by DMA were slightly increased in almost all the biocomposites. The storage modulus (E') of biocomposites was higher for almost all groups of inserted ceramics, with exception of 5%n-HA. In the flexural tests, the biocomposites obtained a great dispersion in average values of fracture loading, presented lower values in relation to pure PLGA. There were difficulties in the processing of biocomposites with Mg-Ca/P and Sr-Ca/P, a factor that can be attributed to lack of homogeneity in the material mixing process. The results suggest modifications in thermal and mechanical properties of the PLGA plates with the bioceramics insertion and provide improvement understanding about of manufactured composites with PLGA and bioceramics.

Electrically pressure sensitive poly(vinylidene fluoride)/polypyrrole electrospun mats

Non-woven mats with highly pressure-sensitive electrical conductivity have been prepared by electrospinning of poly(vinylidene fluoride) (PVDF) containing up to 23 wt% of polypyrrole (PPy) particles synthesized by using dodecylbenzenesulfonic acid (DBSA) as a dopant.

Efeito do tratamento alcalino de fibras de juta no comportamento mecânico de compósitos de matriz epóxi

Neste trabalho foi avaliada a influência do tratamento químico de fibras vegetais nas propriedades mecânicas e dinâmico-mecânicas de resina epóxi reforçada com tecidos de fibras de juta. As fibras foram modificadas a partir de solução de hidróxido de sódio, e caracterizadas por microscopia eletrônica de varredura (MEV), espectrometria no infravermelho com transformada de Fourier (FTIR) e resistência à tração. As análises de FTIR e MEV evidenciaram, respectivamente, que o tratamento alcalino promoveu a remoção parcial da hemicelulose e modificou a morfologia das fibras de juta. Amostras dos compósitos com fibras tratadas e não tratadas foram confeccionadas a partir da laminação manual seguida da moldagem por compressão. Compósitos com fibras tratadas apresentaram propriedades mecânicas e módulo de armazenamento maiores do que as da resina epóxi sem reforço e compósitos com fibras sem tratamento. As micrografias de microscopia eletrônica de varredura (MEV) revelaram que compósitos com fibras tratadas possuem menor quantidade de vazios e menor quantidade de pull-out, sugerindo maior adesão com a matriz polimérica do que os compósitos com fibras sem tratamento.

Inhibition of intracellular growth of Staphylococcus aureus by exposure of infected human monocytes to clarithromycin and azithromycin

The direct effect of clarithromycin and azithromycin on human polymorphonuclear leukocyte (PMN) functions and their intracellular activity against Staphylococcus aureus, phagocytosed by human monocytes, were studied. The presence of both antibiotics, in the range of concentrations from 0.25 to 20 micrograms/ml, did not affect chemotaxis, opsonized-zymosan phagocytosis, respiratory burst measured by nitroblue tetrazolium reduction and phorbol myristate acetate-induced superoxide production, or the microbicidal activity of human PMNs against Candida albicans. Both macrolides were bactericidal against staphylococci in the monocyte system, while bacteriostatic activity was found in cell free system. At concentrations equal to the minimum inhibitory concentrations (MICs) (0.75 and 0.1 respectively for azithromycin and clarithromycin) more than 99% of intraphagocytic S. aureus were killed after 24 h incubation. Increasing the concentrations of each drug above the MICs (5 and 10 MICs) did not alter the killing rate of intracellular bacteria. Moreover, no differences between the intracellular bioactivity of these antibiotics were demonstrated, despite their different uptake kinetics.

Requirements for intracellular accumulation and release of clarithromycin and azithromycin by human phagocytes

Determination of clarithromycin (CL) and azithromycin (AZ) uptake by human polymorphonuclear leukocytes (PMNs), monocytes and alveolar macrophages showed that AZ achieved higher levels than CL. The uptake kinetics of AZ were time-dependent over an 18 h period, while those of CL were similar to erythromycin (ER) kinetics, with a maximum level of incorporation being obtained after a 60 min incubation. The accumulation of both drugs was influenced by extracellular antibiotic-concentrations, PMN viability, extracellular calcium, physiological environmental temperature and pH. The uptake was not modified by inhibitors of cell metabolism or activators of cell membranes. After removal of extracellular antibiotic, the release of AZ from PMNs was very slow: nearly 50% of the drug remained cell-associated after 24 h incubation. The efflux of this derivative was significantly enhanced when drug-loaded PMNs were stimulated by phorbol-myristate acetate (PMA). The kinetics of CL release indicated that this macrolide behaved like ER. Nevertheless, about 10% of the initial cell-associated antibiotic showed a prolonged retention. On the whole, these data suggest that diffusion through cell membranes and trapping into acidic compartments of PMNs are important events in CL and AZ uptake.

Specific and non-specific parameters of the host defence system in patients with superficial fungal infections

Some measures of systemic host defences, i.e. white cell counts, lymphocyte subsets, delayed-type hypersensitivity and polymorphonuclear leucocyte functions, were evaluated in 42 patients suffering from cutaneous superficial mycoses and in 35 healthy volunteers. Patients were divided according to the extent of their lesions into two groups: group A (30 patients) with skin involvement > or = 30% and group B (12 patients) with skin involvement < or = 1%. No significant abnormalities in systemic defence mechanisms were observed in group B patients, whereas multiple alterations of polymorphonuclear phagocyte activities, i.e. chemotaxis, phagocytosis, mitogen-induced superoxide anion production, were observed in patients with extensive lesions. The values of these phagocytic functions remained significantly reduced (P < 0.01) in these patients after recovery and during a 6-month follow-up period.

In vitro activity of two new oral cephalosporins, cefixime and cefdinir (CI 983), on human peripheral mononuclear and polymorphonuclear leukocyte functions

The in vitro effects of cefixime and cefdinir (CI 983), two so-called third-generation oral cephalosporin derivatives, on human polymorphonuclear and mononuclear phagocyte functions (random migration and chemotaxis, specific and nonspecific phagocytosis, nitroblue tetrazolium reduction, superoxide production, microbicidal activity) were studied. Neither antibiotic, in the range of its attainable therapeutic concentration, exhibited any toxic effect on random migration, chemotaxis, metabolic activation and microbicidal mechanisms of phagocytic cells. Cefixime did not interfere in phagocytosis while cefdinir enhanced both phagocytosis frequency and index. The modulating effect on phagocytosis exerted by cefdinir was achieved at very low antibiotic concentrations (0.06 mg/l for polymorphonuclear leukocytes and 0.03 mg/l for monocytes) when non-opsonized zymosan particles were used as phagocytic challenge. Moreover, the effect was demonstrated both in the presence of cefdinir and after pretreatment of cells with the antibiotic and its removal by washings. As for specific phagocytosis, parameters were slightly increased by cefdinir but only the phagocytosis index was significantly improved in the presence of 2 mg/l of antibiotic.

Influence of aging on some specific and nonspecific mechanisms of the host defense system in 146 healthy subjects

The influence of aging on some parameters of systemic host defense mechanisms, i.e. white cell counts, lymphocyte subpopulations, delayed-type hypersensitivity (DTH), polymorphonuclear and mononuclear leukocyte functions, was evaluated. One hundred and forty-six healthy volunteers (60 men and 86 women), aged 25-100 years, were enrolled. None of the subjects had taken any drug in the month before the study. Subjects were divided into three age groups: 25-45, 46-65 and 66-100 years. Groups were comparable in size, and sex distribution was similar throughout all age groups. Elderly people were 51 healthy volunteers between the ages of 66 and 100 years (mean age 79.2). Younger people were 41 subjects between the ages of 46 and 65 years (mean age 54.3) and 53 between the ages of 25 and 45 years (mean age 32.7). As for the comparison between sexes, no significant differences in the values of the studied parameters were found between males and females (p > 0.05). Only quantitative DTH data, i.e. the number of antigens producing positive reactions and the score (sum of positive reaction diameters), were significantly (p < 0.05) reduced in responsive females when compared to males. Aging did not affect white cell counts, lymphocyte subsets and many phagocytic functions, i.e. phagocytosis frequency and index, nitroblue tetrazolium reduction, superoxide production, microbicidal activity against bacteria and yeasts. A significant decrease (p < 0.05) in the chemotactic response to serum-derived chemotactic factors was observed in aged people in comparison to younger subjects. Anergy was more frequent in older (about 29%) than in younger (5-9.4%) healthy volunteers.(ABSTRACT TRUNCATED AT 250 WORDS)

Non specific immunity in aged healthy subjects and in patients with chronic bronchitis

We investigated the effects of aging on some functional activities (chemotaxis, phagocytosis, nitroblue tetrazolium reduction and candidacidal activity) of peripheral polymorphonuclear and mononuclear phagocytes in 96 healthy subjects and 89 patients with chronic bronchitis, aged 40 to 100 years. The subjects were divided according to age into younger (40-65 years) and older (66-100 years) individuals. No subject was taking any drug known to affect phagocytic functions. A few abnormalities in PMN and monocyte functions were observed in aged healthy subjects, in comparison to the younger ones; in fact, only the chemotactic response to complement-derived chemotactic factors was significantly impaired in elderly healthy individuals. On the contrary, multiple alterations of phagocyte activities, i.e., chemotaxis, phagocytosis, and candidacidal activity were observed in aged subjects with chronic bronchitis, compared to healthy adults. However, the results obtained in older and younger patients with chronic bronchitis were superimposable. The present data suggest that the decline in functional activities of phagocytes in the aged could depend on the effect of the underlying chronic bronchitis on the cellular components of the non-specific host defense system, rather than a direct effect of the aging process.

Bioactivity of flurithromycin and other macrolides against intracellular susceptible staphylococci

The intracellular activity of flurithromycin, erythromycin, roxithromycin and miocamycin against susceptible clinical isolates of Staphylococcus aureus, phagocytosed by human monocytes, was investigated. Intracellular bioactivity was studied in a 24-hour assay, using experimental conditions which allowed the intracellular growth of bacteria. A colony counting method was used to differentiate between intracellular bacteriostatic and bactericidal activity of antibiotics. Moreover, the effect of macrolides against extracellular staphylococci was assessed. All agents showed higher intracellular than extracellular activity against staphylococci. At low concentration (0.1 mg/l) they had intracellular bacteriostatic activity. At concentrations higher than the minimal inhibitory ones (1 and 5 mg/l), miocamycin only still produced a bacteriostatic effect while flurithromycin, erythromycin and roxithromycin also showed intracellular bactericidal activity.

A mathematical model for the computation of the forces exerted by the facial orthopedic mask

This study presents a model for the computation of the forces exerted on the chin and on the forehead by the facial orthopedic mask in skeletal Class III malocclusions. Cephalometric data as well as geometry of the mask are taken into account to simulate in quantitative terms the entire approach. A computer program has been implemented to validate the model on a group of patients. Despite the approximations about the mechanical characteristics of the appliance and of the constraints (rigid body, ideal constraints) and despite the unavoidable errors in the estimation of the geometric parameters (dimensions and angles), it is shown that the computation of the forces (in orientation and in magnitude) at the forehead and at the chin is possible. Some practical applications of the model are presented.

Uptake of flurithromycin by human polymorphonuclear phagocytes: partial characterization of the entry mechanism

The ability of flurithromycin and erythromycin to enter human polymorphonuclear phagocytes were studied and compared by a velocity centrifugation gradient technique. Both macrolides were markedly concentrated by human cells and attained cellular to extracellular concentration ratios (C/E) > or = 10. The incorporation was rapid and essentially complete after 60 min incubation. When PMNs were pretreated with formaldehyde, or incubated at low temperatures (4-25 degrees C) or at low pH, the transport ratios of both molecules were reduced. Sodium fluoride and 2,4-dinitrophenol, which decreased erythromycin uptake, did not affect flurithromycin penetration. Perturbation of cell membrane by phorbol myristate acetate, but not by formyl methionyl leucyl peptide, affected C/E ratios of both antibiotics. The addition of amino acids or nucleosides did not influence their transfer into PMNs.

Immunological and clinical effect of long-term oral treatment with RU 41740 in patients with chronic bronchitis: double-blind trial long-term versus standard dose regimen

The immunological and clinical effects of two oral treatment schedules of RU 41740 (standard for 3 months vs. long-term for 6 months) were assessed in 40 patients with chronic bronchitis by a controlled, double-blind, randomized trial. Both treatments significantly improved phagocytosis index of both neutrophils and monocytes, and the phagocytosis frequency and the candidacidal activity of neutrophils, showing the maximum stimulation at the end of the third course of treatment. Both treatment schedules reduced the number and the duration of infectious exacerbations of chronic bronchitis with respect to those observed in the corresponding period of the previous year. However, no significant difference between standard and long-term treatment with RU 41740 was found with respect to the immunological and clinical effect and tolerability.

Evidence for CD8+ cell increase in long-term PUVA-treated psoriatic patients after PUVA discontinuation

Long-term PUVA-treated psoriatic patients given maintenance therapy (UVA doses greater than 1,000 J/cm2) have been demonstrated to undergo lymphopenia and a decrease in the total number of circulating CD3+ and CD4+ T cells. The aim of this study was to assess whether the impairment of T cells is detectable also in psoriatic patients after long-lasting PUVA discontinuation. A group of 34 psoriatic patients (25 males, 9 females; mean age 52.7 +/- 12.82 years), who had previously been treated by PUVA therapy (average cumulative dose 1,898.48 +/- 1,207.12 J/cm2), was studied 1 year or more after discontinuation of PUVA therapy. The patients studied failed to show any impairment in CD3+ and CD4+ cells. Nevertheless, a significant increase (p less than 0.05) in circulating CD8+ cells (both in the percentage and the total number) was detectable in PUVA patients as compared to appropriate controls. The significance and implications of this finding are not known and need further investigations.

[Apical resorption in pre-surgical orthodontics]

Apical root resorption is a frequent phenomenon observed in pre-surgical orthodontic; the reason is double: we deal with adult patients and we often move the teeth in the opposite direction compared to the position obtained in previous inefficacious orthodontic treatments. Notwithstanding the amount of apical root resorption we couldn't record an hyper-mobility of the teeth and a long term evaluation of occlusal stability didn't show any significant change.

[Odontogenic and nonodontogenic epithelial rests. Embryological origin]

The close examination of the central osseous and/or parosteal lesions of the jaws must be reconducted to the study of the main fundamental embryonal processes that take place in the primordial stomodeus. Some pathological lesions can arise from the rests that survive after the disgregation of various odontogenic epithelial structures destined to disappear with growth: the epithelial root sheath, the dental lamina and the external epithelium of the enamel organ. Some osseous lesions can also originate from the nonodontogenic epithelial rests: this tissue comes from the uncompleted obliteration of the ectodermic layer during the processes of union and fusion of the various embryonal components of the maxillary structures.

[Inflammatory odontogenic lesions of the jaws]

The apical granuloma, the periapical abcess and the radicular cyst are the most frequent between the inflammatory odontogenic lesions of the jaws. These three lesions are caused by the necrosis of the pulp but are very different between each other from an histological point of view and they can correspond to different stages of the same pathological process considering the fact that from a granuloma can arise a periapical abcess or a radicular cyst and from a radicular cyst and abcess can originate. About these three pathological processes we discuss in this article the clinical, radiographical, ethiological, microscopical features, we suggest the treatment and the differential diagnosis.

[Apical scars. A healing abnormality]

The Authors presented the clinical report of an apical scar because of the rareness of the case and because of the interesting differential diagnosis: this lesion has a cystic radiological aspect and must be differentiated from the real odontogenic cysts of the jaws; the apical scar does not belong to the cystic pathology and represents just a defect of the healing process: no treatment is requested as the apical scar mustn't be considered a pathology.

[Intraosseous developmental cysts of the jaw. 2]

The Authors conclude the chapter about the central intraosseous developmental odontogenic cysts. Some of them are very rare, others are very similar histogenetically with other more frequent cystic lesions of the jaws. Notwithstanding the radiographic and macroscopic aspect apparently similar, these lesions are very different between each other in their biological activity. The classification, suggested by Hoffman, Jacoway and Krolls lists these lesions from the least to the most aggressive. We have here considered the multiple nevoid basal cell carcinoma syndrome, also known as Gorlin-Goltz syndrome, associated to one or more keratinized maxillary cysts, the calcifying odontogenic cyst, the more frequent and well known dentigerous cyst, the lateral periodontal cyst with its uncertain etiology and the harmless eruption cyst.

[Intraosseous developmental cysts of the jaw. 1]

Discussing the central intraosseous developmental odontogenic cysts of the jaws the Authors have followed the classification suggested by Hoffman et Al. that lists the lesions according to their biological activity. After a short foreword about the most important stages of the embryological dental development, grouped in six phases, the Authors referred to the principal concepts emerging from the literature about the most aggressive developmental odontogenic cysts of the jaws: the primordial cyst and the odontogenic keratocyst of which they have outlined a definition, and referred to the clinical, radiological, ethiological and microscopical data, the treatment and the differential diagnosis.

Gynaecomastia and azoospermia as sole presenting symptoms of feminizing adrenal tumor

Adrenal feminizing tumours are rare but frequently malignant. A case of adrenal feminizing tumour in a 35-year-old man, which presented with gynaecomastia and infertility due to azoospermia, without loss of libido and sexual potency is reported in this paper. Our patient represents a relatively unusual case. The long free interval from the excision allows us to consider the patient cured as despite the pathological malignant features of the neoplasm.

Double-blind trial RU 41740 vs. placebo: immunological and clinical effects in a group of patients with chronic bronchitis

A double-blind trail was performed to investigate the effects of RU 41740, a glycoprotein extract from Klebsiella pneumoniae, on host defenses and its efficacy in reducing the number of exacerbation in 29 evaluable patients with chronic bronchitis, out of 36 patients who entered the study. The drug enhanced the phagocytosis indexes of both polymorphonuclear and mononuclear phagocytes. Increased candidacidal activity of monocytes was also observed. These effects, already detectable after one course of therapy and during the entire period of treatment, were no longer detectable when tested 6 months after the end of treatment. A significantly (p less than 0.05) larger number of patients in the treated group than in the placebo group had no exacerbations during drug administration (0-3 months). Moreover, patients treated with RU 41740 had significantly fewer and shorter episodes of acute exacerbation. The positive decreases in these two parameters persisted throughout the follow-up.

In vitro and ex vivo influence of rifamycins on human phagocytes

We studied the effects of rifamycin SV, rifampicin and rifapentine on human phagocyte functions. Rifamycins inhibited in vitro neutrophil chemotaxis in the range of their therapeutic levels, and they significantly affected the survival of a rifamycin-sensitive strain of Staphylococcus aureus inside human monocytes. Both effects were related to the intraphagocytic penetration of these antibiotics. For the ex vivo studies, 600 mg of rifampicin were orally administered to five subjects with defective S. aureus killing. A significant reduction of neutrophil chemotaxis and increased activity against S. aureus were shown 150 and 210 min after administration of the drug.