Efficacy of short-term induction therapy with low-dose testosterone as a diagnostic tool in the workup of delayed growth and puberty in boys.

PURPOSE: Constitutional delay of growth and puberty (CDGP) represents the most frequent cause of delayed puberty in males, sharing some clinical features with growth hormone deficiency (GHD) and isolated hypogonadotropic hypogonadism (IHH). Short-term induction therapy (SIT) has been approved for the induction of puberty in CDGP. We aim to investigate the efficacy of SIT with transcutaneous testosterone gel (TTG) or intramuscular testosterone therapy (IMTT) in a cohort of CDGP subjects, compared to clinical observation. Furthermore, we aim to evaluate the role of SIT as a diagnostic tool to differentiate CDGP from GHD and IHH subjects. METHODS: The retrospective study included 246 male subjects with delayed puberty. The study population was divided into three groups: TTG, IMTT, and control group (CNT). RESULTS: At 6 months observation, height velocity (HV) was significantly increased in both treated groups compared to CNT group, particularly higher in TTG than IMTT group. A significant testicular enlargement was revealed in both CNT and TTG group compared to IMTT group. Furthermore, LH value was significantly greater in TTG compared to IMTT group. IGF-1 values after SIT rose significantly in both treated groups compared to CNT group. Moreover, almost all GH provocative tests performed after SIT showed a normal GH response. CONCLUSION: SIT with TTG appears to be more effective to induce growth spurt, better tolerated and with a more physiological effect on pubertal induction compared to IMTT in CDGP population. Finally, TTG might be a useful tool in the diagnostic work up to discriminate CDGP from GHD or IHH.

Testosterone positively regulates vagina NO-induced relaxation: an experimental study in rats.

PURPOSE: Female sexual response involves a complex interplay between neurophysiological mechanisms and the nitric oxide (NO)-mediated relaxation of clitoris and vagina. The aim of this study was to evaluate sex steroids regulation of the relaxant pathway in vagina, using a validated animal model. METHODS: Subgroups of OVX Sprague-Dawley rats were treated with 17ß-estradiol, testosterone, or testosterone and letrozole, and compared with a group of intact animals. Masson's trichrome staining was performed for morphological evaluation of the distal vaginal wall, in vitro contractility studies investigated the effect of OVX and in vivo treatments on vaginal smooth muscle activity. RNA from vaginal tissue was analyzed by semi-quantitative RT-PCR. RESULTS: Immunohistochemical analysis showed that OVX induced epithelial and smooth muscle structural atrophy, testosterone and testo + letrozole increased the muscle bundles content and organization without affecting the epithelium while 17ß-estradiol mediated the opposite effects. In vitro contractility studies were performed on noradrenaline pre-contracted vaginal strips from each experimental group. Acetylcholine (0.001-10 µM) stimulation induced a concentration-dependent relaxation, significantly reduced by NO-synthase inhibitor L-NAME and by guanylate cyclase inhibitor ODQ. OVX resulted in a decreased responsiveness to acetylcholine, restored by testosterone, with or without letrozole, but not by 17ß-estradiol. OVX sensitivity to the NO-donor SNP was higher than in the control. Vardenafil, a PDE5 inhibitor, enhanced SNP effect in OVX + testosterone as well as in control, as supported by RNA expression analysis. CONCLUSIONS: Our study demonstrates that testosterone improves the NO-mediated smooth muscle vaginal cells relaxation confirming its role in maintaining the integrity of muscular relaxant machinery.

Higher testosterone is associated with increased inflammatory markers in women with SARS-CoV-2 pneumonia: preliminary results from an observational study.

PURPOSE: Objective of this study was to assess the association between testosterone (T) levels and biochemical markers in a cohort of female patients admitted for SARS-CoV-2 infection in a respiratory intensive care unit (RICU). METHODS: A consecutive series of 17 women affected by SARSCoV-2 pneumonia and recovered in the RICU of the Hospital of Mantua were analyzed. Biochemical inflammatory markers as well as total testosterone (TT), calculated free T (cFT), sex hormone-binding globulin (SHBG), and luteinizing hormone (LH) were determined. RESULTS: TT and cFT were significantly and positively associated with PCT, CRP, and fibrinogen as well as with a worse hospital course. We did not observe any significant association between TT and cFT with LH; conversely, both TT and cFT showed a positive correlation with cortisol. By LOWESS analysis, a linear relationship could be assumed for CRP and fibrinogen, while a threshold effect was apparent in the relationship between TT and procalcitonin, LDH and ferritin. When the TT threshold value of 1 nmol/L was used, significant associations between TT and PCT, LDH or ferritin were observed for values above this value. For LDH and ferritin, this was confirmed also in an age-adjusted model. Similar results were found for the association of cFT with the inflammatory markers with a threshold effect towards LDH and ferritin with increased LDH and ferritin levels for values above cFT 5 pmol/L. Cortisol is associated with serum inflammatory markers with similar trends observed for TT; conversely, the relationship between LH and inflammatory markers had different trends. CONCLUSION: Opposite to men, in women with SARS-CoV-2 pneumonia, higher TT and cFT are associated with a stronger inflammatory status, probably related to adrenal cortex hyperactivity.

Effects of testosterone treatment on clitoral haemodynamics in women with sexual dysfunction.

PURPOSE: To explore the effects of 6-month systemic testosterone (T) administration on clitoral color Doppler ultrasound (CDU) parameters in women with female sexual dysfunction (FSD). METHODS: 81 women with FSD were retrospectively recruited. Data on CDU parameters at baseline and after 6 months with four different treatments were available and thus further longitudinally analyzed: local non-hormonal moisturizers (NH group), n = 37; transdermal 2% T gel 300 mcg/day (T group), n = 23; local estrogens (E group), n = 12; combined therapy (T + E group), n = 9. Patients underwent physical, laboratory, and genital CDU examinations at both visits and completed different validated questionnaires, including the Female Sexual Function Index (FSFI). RESULTS: At 6-month visit, T therapy significantly increased clitoral artery peak systolic velocity (PSV) when compared to both NH (p < 0.0001) and E (p < 0.0001) groups. A similar increase was found in the T + E group (p = 0.039 vs. E). In addition, T treatment was associated with significantly higher FSFI desire, pain, arousal, lubrication, orgasm, and total scores at 6-month visit vs. baseline. Similar findings were observed in the T + E group. No significant differences in the variations of total and high-density lipoprotein-cholesterol, triglycerides, fasting glycemia, insulin and glycated hemoglobin levels were found among the four groups. No adverse events were observed. CONCLUSION: In women complaining for FSD, systemic T administration, either alone or combined with local estrogens, was associated with a positive effect on clitoral blood flow and a clinical improvement in sexual function, showing a good safety profile. TRIAL REGISTRATION NUMBER: NCT04336891; date of registration: April 7, 2020.

Biochemical predictors of structural hypothalamus-pituitary abnormalities detected by magnetic resonance imaging in men with secondary hypogonadism.

PURPOSE: Organic conditions underlying secondary hypogonadism (SH) may be ascertained by magnetic resonance imaging (MRI) of the hypothalamic-pituitary region that could not be systematically proposed to each patient. Based upon limited evidence, the Endocrine Society (ES) guidelines suggest total testosterone (T) < 5.2 nmol/L to identify patients eligible for MRI. The study aims to identify markers and their best threshold value predicting pathological MRI findings in men with SH. METHODS: A consecutive series of 609 men seeking medical care for sexual dysfunction and with SH (total T < 10.5 nmol/L and LH ≤ 9.4 U/L) was retrospectively evaluated. An independent cohort of 50 men with SH was used as validation sample. 126 men in the exploratory sample and the whole validation sample underwent MRI. RESULTS: In the exploratory sample, patients with pathological MRI findings (n = 46) had significantly lower total T, luteinizing hormone (LH), follicle stimulating hormone (FSH) and prostate specific antigen (PSA) than men with normal MRI (n = 80). Receiver Operating Characteristics analysis showed that total T, LH, FSH and PSA are accurate in identifying men with pathologic MRI (accuracy: 0.62-0.68, all p < 0.05). The Youden index was used to detect the value with the best performance, corresponding to total T 6.1 nmol/L, LH 1.9 U/L, FSH 4.2 U/L and PSA 0.58 ng/mL. In the validation cohort, only total T ≤ 6.1 nmol/L and LH ≤ 1.9 U/L were confirmed as significant predictors of pathologic MRI. CONCLUSION: In men with SH, total T ≤ 6.1 nmol/L or LH ≤ 1.9 U/L should arise the suspect of hypothalamus/pituitary structural abnormalities, deserving MRI evaluation.

Risk of heat illness in men and women: A systematic review and meta-analysis.

BACKGROUND: Heat illness (HI) is a growing global concern; its incidence has risen dramatically across the world in recent years. The individual factors whereby elevated core temperature produces HI are not well-understood. Given known physiological differences between men and women pertaining to temperature regulation, we hypothesized that women would be at increased risk of HI than men. OBJECTIVES: We aimed to determine the relative risk of HI in women compared with men through an exhaustive literature review and meta-analysis. METHODS: We search PubMed and Ovid Medline databases from inception to Apr 2017. Search terms included all permutations of sex and heat illness (including heatstroke and exertional heat illness) with no language restrictions. We included adult or adolescent human data reporting comparable male and female HI rates. One reviewer identified and screened titles and abstracts. Two independent reviewers applied eligibility criteria. Disagreements were resolved with a third reviewer. RESULTS: Of 5888 articles identified by searches, 36 were included in the systematic review and 22 in the meta-analysis. The mean (standard deviation) quality score was 3.31(1.25)/5. Overall the rate among women was consistently lower than men across the lifespan. The male: female pooled IRR was 2.28 (p < 0.001, 95% CI: 1.66-3.16). There was modest heterogeneity (between-studies variance (τ2) = 0.02). The rates did not differ significantly when corrected for severity or occupation. DISCUSSION: The rate of HI was significantly increased in men compared with women. Risk for HI might be conferred by psychological and behavioral factors rather than physiological ones. Further research is required to delineate which groups are at greatest risk, leading to the development of mitigation strategies against HI. OTHER: No funding was received. The authors acknowledge the support of the UK Women in Ground Close Combat Review. The Study was registered with PROSPREO CRD42017064739.

Genetics of ncHH: from a peculiar inheritance of a novel GNRHR mutation to a comprehensive review of the literature.

BACKGROUND: Normosmic congenital hypogonadotropic hypogonadism (ncHH) is caused by the deficient production, secretion, or action of gonadotropin-releasing hormone (GnRH). Its typical clinical manifestation is delayed puberty and azoospermia. Homozygous and compound heterozygous mutations in the GNRHR gene (4q13.2) are the most frequent genetic causes of ncHH. OBJECTIVES: (i) Characterization at the molecular level (genetic origin and functional effect) of a unique homozygous mutation (p.Gly99Glu) in a ncHH man; (ii) to provide a comprehensive catalog of GNRHR mutations with genotype-phenotype correlation and comparison of in vitro studies vs. in silico prediction tools. MATERIAL AND METHODS: A ncHH man and his parents, in whom we performed the following: (i) Sanger sequencing, qPCR of the GNRHR gene; (ii) chromosome 4 SNP array; and (iii) competition binding assay and inositol phosphate signaling assay. PubMed and Human Genome Mutation Database (HGMD) search for GNRHR mutations. Bioinformatic analysis of 55 reported variants. RESULTS: qPCR showed two GNRHR copies in the index case. SNP array revealed the inheritance of two homologous chromosomes 4 from the mother (maternal heterodisomy; hUPD) with two loss of heterozygosity regions, one of them containing the mutated gene (maternal isodisomy; iUPD). Functional studies for the p.Gly99Glu mutation demonstrated a right-shifted GnRH-stimulated signaling response. Bioinformatic tools show that commonly used in silico tools are poor predictors of the function of ncHH-associated GNRHR variants. DISCUSSION: Functional analysis of the p.Gly99Glu mutation is consistent with severely decreased GnRH binding affinity (a severe partial loss-of-function mutation). Complete LOF variants are associated with severe and severe/moderate phenotype, whereas partial LOF variants show wide range of clinical manifestations. CONCLUSION: This is the first ncHH patient carrying a novel causative missense mutation of GNRHR with proven 'severe pLOF' due to maternal hUPD/iUPD of chromosome 4. Our literature review shows that functional studies remain essential both for diagnostic and potential therapeutic purposes.

An Italian experience of sequential intravenous and oral azithromycin plus intravenous ampicillin/sulbactam in hospitalized patients with community-acquired pneumonia.

The efficacy and safety of intravenous (i.v.) azithromycin followed by the oral form, given in addition to i.v. ampicillin-sulbactam, were evaluated in 151 patients hospitalized due to community-acquired pneumonia (CAP). Azithromycin 500 mg i.v. once daily plus ampicillin/sulbactam 3 g i.v. twice daily were administered for 2-5 days, then followed by oral azithromycin 500 mg once daily plus the same i.v. ampicillin/sulbactam regimen for a total of 7-10 days of treatment. The clinical response at day 14 was defined as cure, improvement or failure (with the addition of relapse at follow-up at day 30). The other efficacy measures included microbiological (eradication, presumed eradication, persistence, relapse, superinfection) and radiological (resolution, improvement, failure) findings, and outcome of signs and symptoms. Adverse events, vital signs and routine laboratory tests were the safety variables. The number and rate of patients with a positive clinical outcome at day 14 (cured + improved) in the intention-to-treat (ITT) analysis (n = 138) were 119 (86.2%), while 118 (87.4%) were cured or improved in the per-protocol population (PP) subset (n = 135). The rate of success at day 14 was slightly lower in the treated population (78.8%), which included all patients discontinued due to any cause. Clinical failures in the ITT population were 19 (13.8%) at day 14 and 1 (0.9%) at day 30, while 4 patients (3.6%) relapsed at day 30. Signs and symptoms of CAP improved from baseline to endpoint. The results in patients with a pathogen isolated at baseline in the cultures of respiratory tract secretions showed that 17 patients (77.3%) had eradication and 5 (22.7%) had presumed eradication (i.e. absence of adequate sputum for culture) at day 14, with no cases of persistence or superinfection. In the X-ray exam at day 30, 96 patients (85.0%) had resolution, 11 (9.7%) had improvement and 4 (3.5%) had failure. Treatment-related adverse events were reported in 10 patients (6.6%) and caused study discontinuation in 5 of them (one case of angioedema and one case of anaphylactic reaction were serious). No abnormal changes from baseline were found in laboratory parameters. Azithromycin i.v. followed by oral form given in addition to i.v. ampicillin/sulbactam was effective and well tolerated in patients with CAP who required hospital care.

Efficacy and safety of azithromycin 1 g once daily for 3 days in the treatment of community-acquired pneumonia: an open-label randomised comparison with amoxicillin-clavulanate 875/125 mg twice daily for 7 days.

This randomised, open-label, non-inferiority study was designed to demonstrate that a 3-day course of oral azithromycin 1 g once daily was at least as effective as a standard 7-day course of oral amoxicillin-clavulanate 875/125 mg twice daily in the treatment of outpatients with community-acquired pneumonia (Fine class I and II). In total, 267 patients with clinically and radiologically confirmed community-acquired pneumonia were randomly assigned to receive either the azithromycin (n=136) or the amoxicillin-clavulanate (n=131) regimen. At screening, 60/136 (58.8%) and 61/131 (62.9%) respectively had at least one pathogen identified by sputum culture, PCR, or serology. The primary endpoint was the clinical response in the intent-to-treat population at the end of therapy (day 8 to 12). Clinical success rates were 126/136 (92.6%) for azithromycin and 122/131 (93.1%) for amoxicillin-clavulanate (treatment difference: - 0.48%; 95% confidence interval: - 5.66%; 4.69%). Clinical and radiological success rates at follow-up (day 22-26) were consistent with the end of therapy results, no patient reporting clinical relapse. Bacteriological success rates at the end of therapy were 32/35 (91.4%) for azithromycin and 30/33 (90.9%) for amoxicillin-clavulanate (treatment difference: 0.52%; 95% confidence interval - 10.81%; 11.85%). Both treatment regimens were well tolerated: the overall incidence of adverse events was 34/136 (25.0%) for azithromycin and 22/132 (16.7%) for amoxicillin-clavulanate. In both treatment groups, the most commonly reported events were gastrointestinal symptoms. Azithromycin 1g once daily for 3 days is at least as effective as amoxicillin-clavulanate 875/125 mg twice daily for 7 days in the treatment of adult patients with community-acquired pneumonia.

Clinical and bacteriological outcomes in hospitalised patients with community-acquired pneumonia treated with azithromycin plus ceftriaxone, or ceftriaxone plus clarithromycin or erythromycin: a prospective, randomised, multicentre study.

This study compared patients with moderate-to-severe community-acquired pneumonia (CAP) requiring hospitalisation, who received initial therapy with either intravenous ceftriaxone plus intravenous azithromycin, followed by step-down to oral azithromycin (n = 135), with patients who received intravenous ceftriaxone combined with either intravenous clarithromycin or erythromycin, followed by step-down to either oral clarithromycin or erythromycin (n = 143). Clinical and bacteriological outcomes were evaluated at the end of therapy (EOT; day 12-16) or at the end of study (EOS; day 28-35). At baseline, mean APACHE II scores were 13.3 and 12.6, respectively, with >50% of patients classified as Fine Pneumonia Severity Index (PSI) category IV or V. Clinical success rates (cure or improvement) in the modified intent-to-treat (MITT) population at EOT were 84.3% in the ceftriaxone/azithromycin group and 82.7% in the ceftriaxone/clarithromycin or erythromycin group. At EOS, MITT success rates (cure only) were 81.7% and 75.0%, respectively. Equivalent success rates in the clinically evaluable population were 83% and 87%, respectively, at EOT, and 79% and 78%, respectively, at EOS. MITT bacteriological eradication rates were 73.2% and 67.4%, respectively, at EOT, and 68.3% vs. 60.9%, respectively, at EOS. Mean length of hospital stay (LOS) was 10.7 and 12.6 days, and the mean duration of therapy was 9.5 and 10.5 days, respectively. The incidence of infusion-related adverse events was 16.3% and 25.2% (p 0.04), respectively. An intravenous-to-oral regimen of ceftriaxone/azithromycin was at least equivalent in efficacy and safety to the comparator regimen and appeared to be a suitable treatment option for hospitalised patients with CAP.

An open, comparative pilot study of thiamphenicol glycinate hydrochloride vs clarithromycin in the treatment of acute lower respiratory tract infections due to Chlamydia pneumoniae.

The aim of this study was to evaluate the efficacy and tolerability of thiamphenicol glycinate hydrochloride (TGH) i.m. versus clarithromycin in acute lower respiratory infections due to Chlamydia pneumonia. 113 patients with suspected pneumonia were screened. 40 patients with IgM and/or IgA titers > or = 1:16 and/or IgG titers > or = 1:512 were assigned to 10 days of treatment with TGH 1500 mg daily or clarithromycin 1000 mg daily. 34 patients were considered a clinical success. 33 patients were a radiological success. 22 patients showed a decrease in IgG values. 3 patients had an increase in IgG values. Blood/urine values presented no clinically significant variations. Clinical efficacy was similar in both treatment groups. These are the first results confirming in vivo the recent in vitro evidence that TGH is effective against acute lower respiratory tract infections due to C. pneumoniae, thus representing an alternative therapy to clarithromycin.

Basis for nebulized antibiotics: droplet characterization and in vitro antimicrobial activity versus Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa.

The aims of this study were to (1) quantify the particle size characteristics of several antibiotics considered suitable for aerosol therapy after aerosolization with the PARI IS/2 nebulizer (Pari GmbH, Sarnberg, Germany) and (2) determine the degree to which in vitro antimicrobial activity of these antibiotics is maintained after nebulization. The aerosolized drugs were tobramycin sulfate, streptomycin, and imipenem, with saline solution as the control. Mean mass aerodynamic diameter of the nebulized drugs was 3.25 microns for tobramycin, 2.26 microns for imipenem, and 2.38 microns for streptomycin. In vitro tests showed that tobramycin and imipenem were unaltered in their bacteriostatic activity against strains of Escherichia coli (American Type Culture Collection [ATCC] 25922) and Staphylococcus aureus (ATCC 29213) as well as against Pseudomonas aeruginosa (ATCC 27853) with minimal inhibitory concentration (MIC) values less than 0.3 microgram/mL. Nebulized streptomycin showed significantly higher MIC values against P. aeruginosa (ATCC 27853). These results suggest that tobramycin and imipenem may be prescribed as an aerosol generated by jet nebulization (PARI IS/2) to treat S. aureus, E. coli, and P. aeruginosa infections without any risk of altering the drugs minimum bacteriostatic activity by the nebulization process. Aerosolization of streptomycin with this nebulizer may not be as effective against P. aeruginosa because it seems to alter the bacteriostatic activity.

Myasthenic inspiratory vocal cord dysfunction: efficacy of nasal continuous positive airway pressure treatment.

Myasthenic vocal cord dysfunction (VCD), presenting with severe inspiratory stridor, was successfully treated with nasal continuous positive airway pressure (nCPAP), thus giving the medical staff time to make the diagnosis and avoiding intubation or tracheostomy. An important sign leading to diagnosis was the very high MEF(50)/MIF(50) ratio calculated from the flow-volume loop. nCPAP treatment induced prompt remission of stridor and a sharp reduction in the MEF(50)/MIF(50) ratio from 9.90 to 1.36. A review of the literature has shown that VCD with inspiratory stridor is an unusual onset symptom of myasthenia gravis and that nCPAP treatment may avoid emergency oral/tracheal intubation and tracheostomy. After diagnosis, the patient underwent thymectomy, and today, 3 years later, he is well without any further therapy.

Nasal-continuous positive airway pressure in the treatment of near-drowning in freshwater.

In patients who have experienced near-drowning, hypoxemia is the major clinical consequence. We report two cases of patients who have experienced near-drowning in freshwater who were successfully treated with nasal-continuous positive airway pressure (N-CPAP) plus oxygen therapy. Both patients presented a radiographic appearance of bilateral pulmonary edema. We suggest the use of N-CPAP as an easier and less costly alternative to tracheal intubation for treating near-drowning in patients who are breathing spontaneously and who have not experienced loss of consciousness.

A phase II trial of combined chemotherapy and surgery in stage IIIA non-small cell lung cancer.

A poor prognosis for patients with Stage IIIA clinical N2 treated by surgery alone has led clinical researchers to find a new treatment modality to improve the curative potential of surgery. Many Phas II trials have been carried out with induction chemo- or chemo-radiotherapy prior to surgery. From June 1988 to July 1991, 46 patients with non-small cell lung cancer (NSCLC) Stage IIIA clinical N2 entered a Phase II induction-chemotherapy trial. Patients received 2-3 cycles of high-dose cisplatin and etoposide. Forty-five were evaluable for response; the response rate was 82% (37/45: 3 CR, 34 PR). Toxicity was primarily hematologic. Surgical resection was performed in 35 patients; radical resection was possible in 28 patients (62%); three patients were incompletely resected and two patients were only explored. Three deaths were surgery-related. Median survival was 24.5 months with a 2-year survival of 53%. Cisplatin with etoposide is an active and safe induction chemotherapy regimen for NSCLC Stage IIIA N2 with a high response rate. The median survival seems to be prolonged and therefore, randomized trials are needed to compare this approach with other treatment modalities.

Effect of bamiphylline on tracheobronchial mucus clearance in subjects with smokers' simple chronic bronchitis.

A double-blind study versus placebo was performed to assess the effect of bamiphylline, a new xanthylic derivative, on tracheobronchial mucus clearance (TBMC) in smokers with simple chronic bronchitis and impaired mucus clearance as compared to normal controls. Twenty patients were enrolled and divided into two randomized groups. The first group was treated with bamiphylline (600 mg b.d.) for 15 days, while the second group received placebo with the same oral dosage regimen. Complete clinical-functional examinations were made before and after the test period to establish the effects of treatment. At the end of the study, only the group treated with bamiphylline showed a net increase in mucus clearance (mean radioaerosol elimination 28 +/- 7% before treatment and 38 +/- 11% after treatment; p < 0.01) and an improvement in the clinical score and pulmonary function parameters, in particular the residual volume (RV = 3.41 +/- 0.75 liters before treatment and 2.7 +/- 0.6 after treatment; p < 0.01) and the forced expiratory volume at 1 s (FEV1 = 2.37 +/- 0.7 liters before treatment and 2.88 +/- 0.5 after treatment; p < 0.05). No side effects or adverse reactions that could be attributed to the study drug were observed.

Encapsulation of Cryptococcus neoformans regulates fungicidal activity and the antigen presentation process in human alveolar macrophages.

Our previous studies have shown that unstimulated alveolar macrophages (AM) play a predominant role as antigen-presenting cells in Cryptococcus neoformans infections, while the function as effector cells seems to be of minor relevance. The present study focuses on the role of encapsulation of C. neoformans on fungicidal activity and the antigen presentation process of AM. Fungicidal activity in unstimulated AM occurs to a higher degree when the acapsular strain is employed, but this is impaired compared with other natural effectors, such as peripheral blood monocytes (PBM) and polymorphonuclear (PMN) cells. Cryptococcus-laden AM also induce a higher proliferative response in autologous CD4+ lymphocytes when the acapsular strain is used compared with encapsulated yeast. The enhanced blastogenic response is, in part, ascribed to an augmented IL-2 production by T cells. In addition, higher levels of interferon-gamma (IFN-gamma), but not IL-4, are produced by the responding T cells, when the acapsular strain is used compared with the encapsulated yeast. Moreover, IFN-gamma is able to induce fungicidal activity in AM against the encapsulated yeast and augments killing activity of the acapsular strain. This phenomenon is not mediated by nitric oxide production, but is correlated with an enhancement of fungicidal activity of cytoplasmic cationic proteases. We speculate that encapsulation of C. neoformans could down-regulate the development of the immune response mediated by Cryptococcus-laden AM at lung level.