Oral fluconazole for vaginal candidiasis

The recent surge of interest in fluconazole is due to its approval by the U.S. Food and Drug Administration for use as a single 150-mg oral dose in the treatment of vaginal candidiasis. Fluconazole is a triazole antifungal agent that acts primarily by inhibiting sterol synthesis in the fungal cell membrane. Recent studies have shown that a single dose of oral fluconazole is as effective as intravaginal antifungal agents. Many physicians and patients prefer this single-dose regimen because of its low rate of side effects, cost-effectiveness and ease of administration.     

Importance of beta2-microglobulin in murine resistance to mucosal and systemic candidiasis

beta2-Microglobulin knockout (beta2m-/-) mice, which lack major histocompatibility complex class I expression and are deficient in CD8alpha/beta T-cell receptor alpha/beta (TcRalpha/beta) T cells, were as resistant to systemic (intravenous) challenge with Candida albicans as immunocompetent controls. Conversely, the beta2m-/- mutant mice were susceptible to systemic candidiasis of endogenous origin despite the induction of C. albicans-specific antibody and cell-mediated immune responses after colonization with a pure culture of C. albicans. Despite some superficial and transient infections of tongues and esophagi (detected by histology) at 1 to 2 weeks after oral colonization and gastric infections (cardia-antrum section) which were observed at 10 to 12 weeks after oral challenge, C. albicans-colonized beta2m-/- mice showed an overall resistance to candidiasis in other mucosal and cutaneous tissues. These data suggest that immune defects that accompany the loss of beta2-microglobulin play an important role in murine resistance to gastric and disseminated candidiasis of endogenous (intestinal tract) origin and that innate immunity and CD4 TcRalpha/beta as well as CD8alpha/alpha TcRalpha/beta (or -gamma/delta) T cells play an important role in resistance to systemic, cutaneous, and nongastric mucosal tissues.     

Curative treatment with fluconazole in 5 cases of invasive candidiasis

BACKGROUND: Amphotericin B is the treatment of choice for invasive and disseminated Candida sp. infections. Fluconazole is an antifungal drug with less toxicity. Because of its pharmacokinetic properties, fluconazole can be specially useful in the treatment of invasive candidiasis. Although it is useful in several forms of candidiasis, its efficacy in deep-seated candidal infections is not totally proved due to the lack of comparative studies with amphotericin. In order to contribute new data about the usefulness of fluconazole in the treatment of invasive candidiasis, we report 5 patients which cured with this antifungal drug. METHODS: The clinical records of those patients with invasive candidiasis that cured with fluconazole were retrospectively reviewed. RESULTS: Fluconazole was used in 2 patients after detecting toxicity to amphotericin. Fluconazole was used from the beginning in the other 3 patients. None of the patients were neutropenic. All the patients cured without recurrence. CONCLUSIONS: In this series, the employment of fluconazole was a non-toxic and effective alternative to amphotericin B in nonneutropenic patients with invasive candidiasis.     

Combination therapy with fluconazole and flucytosine in the murine model of cryptococcal meningitis

This study elucidates the role of combined fluconazole and flucytosine as therapy for cryptococcosis in the murine model of meningitis. Three strains of Cryptococcus neoformans for which the range of fluconazole MICs was wide--2 microg/ml (susceptible strain), 8 microg/ml (moderately susceptible strain), and 32 microg/ml (resistant strain)--were used for infection. One day postinfection, the mice were randomized into eight treatment groups: placebo; flucytosine (40 mg/kg of body weight/day); fluconazole at 3 mg/kg/day (low dosage), 10 mg/kg/day (moderate dosage), or 20 mg/kg/day (high dosage); and combined flucytosine and fluconazole at low, moderate, or high doses of fluconazole. Three major findings were demonstrated: (i) correlation between the MICs for the isolates and the in vivo effectiveness of fluconazole as assessed by the reduction in cryptococcal brain burden, (ii) a dose-response curve (a higher dose of fluconazole was significantly more efficacious than a lower dose [P < 0.001]), and (iii) synergism between fluconazole and flucytosine (therapy with a combination of fluconazole and flucytosine was superior to therapy with either agent alone [P < 0.01]).     

Oropharyngeal candidiasis resistant to fluconazole in patients infected by HIV

Uncomplicated extracapsular cataract extraction (EC) followed by posterior chamber lens implantation (PCL) has been shown to cause long-term lowering of intraocular pressure (IOP) in most patients. Since it has been suggested that Neodymium: YAG (Nd:YAG) laser capsulotomy can provoke persistent glaucoma, we examined the hypothesis that Nd:YAG laser capsulotomy may lead to a permanent elevation of IOP. In a case-control study, we compared two groups of 75 normotensive patients, who were unilaterally pseudophakic after phacoemulsification (PE) + PCL. Patients in group 1 had undergone Nd:YAG capsulotomy at least 2 months prior to this study, while in group 2 the posterior capsule was intact. Both groups were selected at random. Prior to surgery, none of the patients had suffered from glaucoma. Goldmann applanation tonometry was performed in both eyes of each patient and from that the ratio of IOP(pseudophakic)/IOP(phakic) was calculated. The distribution of this ratio for the two groups was compared using the Wilcoxon signed-rank test. There were 52 female and 23 male patients in group 1 versus 56 female and 19 male patients in group 2. Their mean ages were 75 + or -11 (group 1) and 75 + or - 9 years (group 2). The mean interval after PE + PCL was 48 + or - 29 months for patients with Nd:YAG capsulotomy and 16 + or - 17 months for patients with intact posterior capsule. Since the Nd:YAG capsulotomy, 28 + or - 23 months had elapsed on average. The median ratio of IOP (pseudophakic)/IOP(phakic) was higher in the Nd:YAG capsulotomy group than in the group of patients with an intact posterior capsule (1.00 vs. 0.80; p < 0.0001). There was almost no percentile, for which the distribution curve of group 1 intersected the curve of group 2. The median IOP in pseudophakic eyes was 14 mm Hg in group 1 and 12 mm Hg in group 2 (p<0.0001). These results are in accordance with the hypothesis that Nd:YAG capsulotomy will raise IOP permanently in most patients. Therefore Nd:YAG capsulotomy may harbor the risk of glaucomatous optic nerve damage in the long run. Long-term follow-up seems advisable in order to prevent possible glaucoma damage.     

A 70-kilodalton recombinant heat shock protein of Candida albicans is highly immunogenic and enhances systemic murine candidiasis

The 70-kDa recombinant Candida albicans heat shock protein (CaHsp70) and its 21-kDa C-terminal and 28-kDa N-terminal fragments (CaHsp70-Cter and CaHsp70-Nter, respectively) were studied for their immunogenicity, including proinflammatory cytokine induction in vitro and in vivo, and protection in a murine model of hematogenous candidiasis. The whole protein and its two fragments were strong inducers of both antibody (Ab; immunoglobulin G1 [IgG1] and IgG2b were the prevalent isotypes) and cell-mediated immunity (CMI) responses in mice. CaHsp70 preparations were also recognized as CMI targets by peripheral blood mononuclear cells of healthy human subjects. Inoculation of CaHsp70 preparations into immunized mice induced rapid production of interleukin-6 (IL-6) and tumor necrosis factor alpha, peaking at 2 to 5 h and declining within 24 h. CaHsp70 and CaHsp70-Cter also induced gamma interferon (IFN-gamma), IL-12, and IL-10 but not IL-4 production by CD4+ lymphocytes cocultured with splenic accessory cells from nonimmunized mice. In particular, the production of IFN-gamma was equal if not superior to that induced in the same cells by whole, heat-inactivated fungal cells or the mitogenic lectin concanavalin A. In immunized mice, however, IL-4 but not IL-12 was produced in addition to IFN-gamma upon in vitro stimulation of CD4+ cells with CaHsp70 and CaHsp70-Cter. These animals showed a decreased median survival time compared to nonimmunized mice, and their mortality was strictly associated with organ invasion by fungal hyphae. Their enhanced susceptibility was attributable to the immunization state, as it did not occur in congenitally athymic nude mice, which were unable to raise either Ab or CMI responses to CaHsp70 preparations. Together, our data demonstrate the elevated immunogenicity of CaHsp70, with which, however, no protection against but rather some enhancement of Candida infection seemed to occur in the mouse model used.     

Interleukin-10 reduces the systemic inflammatory response in a murine model of intestinal ischemia/reperfusion

BACKGROUND: Intestinal ischemia/reperfusion (I/R) is known to increase systemic cytokine levels, as well as to activate neutrophils in distant organs. This study was designed to investigate the effect of interleukin-10 (IL-10) on cytokine release, pulmonary neutrophil accumulation, and histologic changes in a murine model of I/R. METHODS: Forty female Swiss-Webster mice were divided into four groups. Group 1 underwent 45 minutes of superior mesenteric artery occlusion followed by 3-hour reperfusion (I/R). Group 2 underwent laparotomy alone (Sham). Group 3 underwent I/R, but was treated with IL-10, 10,000 units IP every 2 hours, starting 1 hour before reperfusion (Pretreatment). Group 4 was treated with an equal dose of IL-10, starting 1 hour after reperfusion (Posttreatment). All animals were killed at 3 hours, standard assays were performed for serum cytokine levels, and lung myeloperoxidase activity and intestinal histology were scored. RESULTS: Serum cytokines (TNF-alpha and IL-6), lung myeloperoxidase levels, and histologic score were significantly reduced when IL-10 was administered either before or after reperfusion. CONCLUSIONS: IL-10 reduced the severity of local and systemic inflammation in a murine model of intestinal I/R when given before or after reperfusion injury. These observations suggest that IL-10 may exert its effect by blocking cytokine production and distant organ neutrophil accumulation.     

Treatment of murine disseminated candidiasis with L-743,872

L-743,872 (M991), which is a pneumocandin derivative, was evaluated in a mouse model of disseminated candidiasis caused by a fluconazole-resistant isolate of Candida albicans. In immunocompetent mice M991 prolonged survival at doses as low as 0.0125 mg/kg of body weight per day. In neutropenic mice 0.05 mg/kg was the lowest effective dose. M991 is a very potent drug for treatment of disseminated candidiasis.     

Oropharyngeal candidiasis in patients with AIDS: randomized comparison of fluconazole versus nystatin oral suspensions

A total of 167 human immunodeficiency virus (HIV)-infected patients with oropharyngeal candidiasis were randomly assigned to receive 14 days of therapy with liquid suspension fluconazole (100 mg once daily) or liquid nystatin (500,000 U four times daily). At day 14, 87% of the fluconazole-treated patients were clinically cured, as opposed to 52% in the nystatin-treated group (P < .001). Fluconazole eradicated Candida organisms from the oral flora in 60%, vs. a 6% eradication rate with nystatin (P < .001). The fluconazole group had fewer relapses noted on day 28 (18%, vs. 44% in the nystatin group; P < .001). This relapse difference no longer existed by day 42. Fluconazole oral suspension as a systemic therapy was more effective than liquid nystatin as a topical therapy in the treatment of oral candidiasis in HIV-infected patients and provided a longer disease-free interval before relapse.     

Interactions of itraconazole with amphotericin B in the treatment of murine invasive candidiasis

The interactions of amphotericin B and itraconazole were studied in murine invasive candidiasis. Candida albicans-infected mice were treated for 10 consecutive days, 24 h after infection. Survival was monitored over 30 days and kidney cultures were done. Mice treated with amphotericin B (0.2 mg/kg/day intraperitoneally) or itraconazole (100 mg/kg/day by oral gavage in two divided doses/ day) had a 30-day survival of 20% or 40%. Concomitant administration of both drugs resulted in 100% mortality; 90% of mice treated with amphotericin B (1 mg/kg/day) survived. With the combination, 100% were dead by day 28 (P < or = .001 vs. amphotericin B). With sequential therapy (i.e., 5 days with one drug and then 5 days with the other), survival was inferior to that with amphotericin B alone but similar to that with itraconazole alone. Kidney culture results confirmed the antagonism of the combination compared with amphotericin B alone. In treatment of murine invasive candidiasis, the concomitant or sequential use of amphotericin B and itraconazole results in a negative interaction.     

Efficacy of fluconazole in the treatment of upper gastrointestinal candidiasis in neutropenic patients with cancer: factors influencing the outcome

Fluconazole has proved to be effective in treating oropharyngeal and esophageal candidiasis in immunocompromised patients. However, sufficient data are lacking regarding the efficacy of this agent in neutropenic hosts. The aim of the present study was to determine the clinical and mycological efficacy of fluconazole and to define the factor(s) affecting the outcome of fluconazole therapy in severely neutropenic patients (peripheral neutrophil count, < 500/microL) with cancer who have oropharyngeal and/or esophageal candidiasis. One hundred eleven patients with 129 episodes of candidal infections were treated with intravenous and consequently oral fluconazole (200 mg/d and 100 mg/d, respectively). Overall clinical cure and mycological eradication rates were 82% and 56%, respectively. Persistent neutropenia (P < .01), infection with a non-albicans strain of Candida (P = .012), and administration of antifungal therapy during the second or a later neutropenic episode (P < .002) were independently associated with a worse outcome. We conclude that fluconazole is effective in the treatment of upper gastrointestinal candidiasis in neutropenic patients with cancer. Effective treatment of the underlying malignancy, with the resultant recovery from neutropenia, and the determination of the species of infecting Candida isolates are required for the prediction of the outcome of antifungal therapy.     

Virulence characteristics of oral treponemes in a murine model

This study was designed to investigate the virulence characteristics of Treponema denticola, T. socranskii, T. pectinovorum, and T. vincentii following challenge infection of mice. These microorganisms induced well-demarcated, dose-dependent, raised subcutaneous (s.c.) abscesses which were similar in time of onset, lesion progression, and duration of healing. Only viable cells were capable of inducing these characteristic s.c. abscesses. Histological examination of the skin lesion 3 and 5 days postinfection revealed abscess formation in the s.c. tissues, and abundant spiral organisms were demonstrated to be present in the abscess. Host resistance modulation by dexamethasone (neutrophil alteration) and cyclophosphamide (neutrophil depletion) pretreatment had a minimal effect on the virulence expression by any of these treponemes. The T. denticola isolates demonstrated significant trypsin-like protease (TLPase) activity, while both T. socranskii and T. vincentii were devoid of this activity. Interestingly, T. pectinovorum strains were heterogeneous with respect to TLPase as high producers, low producers, and nonproducers. However, no differences in lesion formation were noted regardless of whether the species expressed this proteolytic activity or whether treatment with N alpha-p-tosyl-L-lysine chloromethyl ketone (TLCK) and dithiothreitol was performed. These results showed that (i) a murine model may be used to evaluate virulence expression by oral treponemes; (ii) while TLPase activity varies among the oral treponemes, this protease does not appear to participate in abscess induction in the mouse model; and (iii) T. pectinovorum strains show variation in TLPase activity.     

A novel model of cutaneous candidiasis produced in prednisolone-treated guinea-pigs

In an attempt to develop an animal model of cutaneous candidiasis useful for the pre-clinical evaluation of antifungal drugs, experimental cutaneous Candida albicans infections were produced in mature and immature guinea-pigs treated with prednisolone. The morbidity of this model in terms of the extent and the duration of the superficial infection was compared with that of two other reported models: those produced by alloxan treatment, or the use of occlusive dressings. Infected animals were also included which received neither of these treatments. The Candida infection continued steadily for 14 days or more in both mature and immature animal groups treated subcutaneously with prednisolone and appeared to be more suitable than that produced with alloxan treatment or under occlusive dressings. In prednisolone-induced infection, most of the micro-organisms were confined to the epidermis and there was no evidence of their dermal penetration during the 14 day experimental period. In view of these facts, we attempted a more quantitative method by counting viable Candida in order to evaluate antimycotics in a shorter therapy period during which animals would receive less exposure to the vehicle. These findings appear to indicate that the experimental model of cutaneous C. albicans infection produced in prednisolone-treated mature and immature guinea-pigs would be useful for studies on the therapeutic efficacy of antifungal agents against cutaneous candidiasis.     

Subzero nonfreezing preservation in a murine limb replantation model

This study was designed to examine the most effective temperature for hypothermic storage, without freezing, to prolong ischemic tolerance in an amputated murine hindlimb model. We measured freezing points in the calf muscle and the subcutaneous tissue of the foot in the amputated limbs of Fisher 344 strain male inbred rats. The highest freezing point was -1.5 degrees C, which was recorded in the calf muscle. To prevent freezing in any of the tissues in the amputated limb, the temperature for the lowest nonfreezing preservation was defined as -1 degrees C. The amputated limbs were preserved at subzero nonfreezing temperature (-1 degrees C) and at 4 degrees C for 4, 8, 12, 24, 48, and 72 h, and were then transplanted to other inbred rats by microsurgical techniques. We evaluated the vascular patency of the anastomoses by direct observation and performed histological examinations on the seventh day after replantation. Subzero nonfreezing preservation of a limb at -1 degrees C for 72 h was significantly superior to hypothermic preservation at 4 degrees C for 72 h in terms of anastomotic patency rates (P < 0.05). The histology of skeletal muscles preserved at -1 degrees C for 8 h showed greater similarity to the normal situation than the histology of those preserved at 4 degrees C for 8 h. Bone viability with osteoblastic activity was maintained in grafted limbs preserved at -1 degrees C for 72 h, but in the limbs preserved at 4 degrees C for 72 h the bone was not viable, showing no osteoblastic activity. Clinically, the period of ischemia in major limb replantation at normal ambient temperatures is limited to about 6 h. In this study, the maximum ischemia time for replantation of a limb containing muscle tissue was prolong to 8 h at -1 degrees C, but the maximum ischemia time at 4 degrees C could not be prolonged to 8 h. Our results suggest that, in the major replantation of a limb containing muscular tissue, hypothermic preservation at -1 degrees C would be more useful than preservation at 4 degrees C.     

Comparison of therapeutic activity of fluconazole and itraconazole in the treatment of oesophageal candidiasis in AIDS patients: a double-blind, randomized, controlled clinical study

The aim of this study was to assess the role and therapeutic efficacy of two azole antifungal drugs, fluconazole and itraconazole, in the treatment of endoscopically-diagnosed Candida oesophagitis in patients with Acquired Immunodeficiency Syndrome (AIDS). The study considered 120 Human Immunodeficiency Virus (HIV)-positive patients (67 males and 53 females, mean age 27 +/- 5) at their first episode of oesophageal candidiasis diagnosed by endoscopy (Kodsi's grade II endoscopic classification). The patients were double-blindly randomized into 2 groups of 60 patients each according to the pharmacological therapy administered: a) the patients in the first group received fluconazole (100 mg b.i.d. per os); b) the patients in the second group received itraconazole (100 mg b.i.d. per os). In order to evaluate the efficacy of the pharmacological therapy, a clinical examination was performed every week up to the end of the follow-up period (2 months); endoscopic examination was performed at the end of pharmacological treatment (3 weeks). All patients selected for the study gave their informed consent. Complete remission of endoscopic lesions was observed in 45 patients (75%) in the fluconazole group and in 23 patients (38%) in the itraconazole group (p < 0.001); partial remission of endoscopic lesions was observed in 15 patients (25%) in the fluconazole group and in 28 patients (47%) in the itraconazole group (p < 0.05). No response was observed in 9 patients (15%) in the itraconazole group. Complete clinical remission was observed in 47 patients (78%) in the fluconazole group and in 44 patients (73%) in the itraconazole group (p = n.s.); partial clinical remission was observed in 13 patients (22%) in the fluconazole group and in 12 patients (20%) in the itraconazole group (p =- m.s.). No clinical response was observed in 4 patients (7%) in the itraconazole group. No side-effects worthy of note were observed in the patients of either treatment group. The results of this study demonstrated that fluconazole is associated with higher rates of endoscopic and clinical cure than itraconazole, with a statistically significant difference as regards endoscopic cure. Both drugs appear to be safe and well tolerated. Nevertheless, further controlled clinical investigations are needed to improve our knowledge of the therapeutic action of antifungal drugs in the treatment of Candida oesophagitis in HIV disease.     

A family of bicistronic vectors to enhance both local and systemic antitumor effects of HSVtk or cytokine expression in a murine melanoma model

The herpes simplex virus-thymidine kinase/ganciclovir (HSVtk/GCV) system produces both direct and immune-mediated tumor cell killing. Here, we compare the efficacy of HSVtk/GCV with cytokines, alone and in combination, on the tumorigenicity and immunogenicity of B16 cells. With respect to single gene modifications, only HSVtk/GCV, or high-level interleukin-2 (IL-2) secretion, completely prevented tumor growth, whereas granulocyte-macrophage colony-stimulating factor (GM-CSF) generated the best levels of long-term systemic protection. To augment both local killing and immune activation, we constructed bicistronic constructs that express HSVtk and a cytokine within the same cell. Co-expression of HSVtk with IL-2 or GM-CSF enhanced the local antitumor activity of any gene alone. In a tumor-prevention model, HSVtk killing, in an environment preprimed with GM-CSF, generated the best long-term immune protection. However, in a short-term therapy model, continued IL-2 expression was most effective against 3-day established tumors. This probably reflects differences in the activities of IL-2 and GM-CSF in generating short-term, nonspecific immune stimulation compared to long-term immunological memory, respectively. As a prelude to in vivo delivery experiments, we also demonstrated that these bicistronic cassettes can be packaged normally into retroviral (5 x 10(5) virus/ml from pooled populations) and adenoviral vectors (5 x 10(9) virus/ml) and function as predicted within virally infected cells. This family of bicistronic vectors can be used to stimulate synergy between suicide and cytokine genes, overcomes the problems of delivering two genes on separate vectors, and should allow easier preparation of vectors for the delivery of multiple genes to patients' tumor cells.     

Mixed cryoglobulinemia as a model of systemic vasculitis

Leukocytoclastic vasculitis is the dominant lesion of mixed cryoglobulinemia (MC). The high prevalence of antibodies to hepatitis C virus (HCV) in association with the higher concentration of HCV RNA genomic sequences in the cryoglobulins suggests a close relationship between MC and HCV infection and strongly supports the view that this virus plays a key role in causing vascular damage. Analysis of the composition of immune complexes (ICs) provides evidence that cryoglobulins include virions mostly bound to IgG that is specifically reactive with HCV-related proteins, which in turn are crosslinked by monoclonal IgM with rheumatoid factor (RF) activity, frequently bearing the WA crossidiotype (XId). This structure is similar (if not identical) to that of circulating ICs from HCV-infected patients without cryoglobulins, suggesting that the virus may be directly responsible for the production of WA RF. Evidence for the role of circulating cryoproteins in the pathogenesis of cutaneous and renal vasculitis stems from the demonstration of HCV-related proteins and/or HCV RNA genomic sequences in the vessel wall of patients with MC. Our data indicate that endothelial cells are fully susceptible to infection by and replication of HCV, and support the contention that they serve as sufficient targets for the binding of HCV proteins expressed on the cell surface to serum immunoglobulins. The in situ demonstration of IgM RF WA XId adds further evidence that RF of the WA group participates in the development of vasculitis and probably stabilizes the binding of IgG antibodies. Lymphocytes may be crucial in the infection of endothelial cells by acting as a circulating viral reservoir. After encouraging initial results, controlled trials have defined the substantive efficacy of IFN-alpha in the treatment of MC. A response of IFN can be achieved in more than 50% of patients and includes improvement of cutaneous vasculitis and renal function. This clinical response is accompanied by a reduction in hepatitis C viremia, serum cryoglobulin concentration, and IgM RF synthesis. However, almost 80% of responders eventually have a clinical and biochemical relapse. Additional studies are required to improve the outcome and extension of this therapy, define the best candidates, and indicate the situations in which it is needed.