A Clinical Comparison of Two Formulations of Tobramycin 0.3% Eyedrops in the Treatment of Acute Bacterial Conjunctivitis

Purpose

To compare the safety and efficacy of a new enhanced viscosity ophthalmic formulation of tobramycin, given twice daily (BID), with the existing four times daily (QID) treatment regimen in patients with acute bacterial conjunctivitis.

Methods

This was a 12-day, multicenter, observer-masked, randomized, parallel group study. Patients received one drop of tobramycin 0.3% (3 mg/mL) enhanced viscosity ophthalmic solution BID or tobramycin 0.3% (3 mg/mL) ophthalmic solution QID in the affected eyes for 7 days. The primary efficacy variable was the percentage of patients with sustained cure/presumed bacterial eradication based on clinical judgment at the test-of-cure visit (Day 12). Pretherapy bacterial isolates were obtained and tested for susceptibility to tobramycin by determination of minimum inhibitory concentrations (MIC).

Results

A total of 276 patients were enrolled in the study and 203 of these were culture positive and attended all follow-up examinations. In this group, 98% of those treated with tobramycin enhanced viscosity ophthalmic solution and 99% of those treated with tobramycin 0.3% ophthalmic solution were categorized as having sustained cure/presumed eradication at the test-of-cure visit (p=0.6037). Reported adverse events were not serious, mild to moderate in severity, and generally did not prevent continuation in the study. Several pretreatment pathogens demonstrated tobramycin resistance (MIC > 4 mg/mL). However, therapy with both treatments was effective in the majority of the cases.

Conclusions

Tobramycin enhanced viscosity ophthalmic solution is well tolerated and has equivalent efficacy to the established treatment regimen with a simplified posology. The formulation provides an alternative therapy for acute bacterial conjunctivitis that should improve patient compliance and satisfaction.

Bradykinin shifts endothelial fluid passage from para- to transcellular routes

The signalling peptide bradykinin (BK) is implicated in inflammation and angiogenesis. It promotes fluid transport from blood vessels to interstitial space, and thus facilitates oedema formation. To clarify whether paracellular or transcellular pathways mediate this effect, we investigated the BK-stimulated fluid transport across endothelial monolayers in vitro by comparison of electrical and fluorescence methods. Electrical cell impedance sensing monitored a biphasic response of cell layers to BK with high time resolution: a short decrease (18%, 1 min) was followed by a more sustained increase in paracellular resistance (30%, 10 min). The two phases can be assigned to second messengers of the BK-signalling pathway: Ca(2+) for the decrease and cyclic adenosine monophosphate for the rise of resistance, respectively. Despite tightening of the intercellular clefts, BK increased the fluid permeability by 39%, indicating transcellular fluid transport. Additionally, BK stimulated both in- and outwardly directed membrane trafficking as assessed by vesicular fluid uptake (by 49%) and secretion of von Willebrandt factor (by 85%). In conclusion, the combination of electrical and fluorescence data suggests that BK induces a shift from para- to transcellular fluid transport across endothelium.

Murine acariasis. II. Immunological dysfunction and evidence for chronic activation of Th-2 lymphocytes

The authors describe the immunological profile of BALB/c mice with Mite-Associated Ulcerative Dermatitis (MAUD)-like disease, due to Myocoptes musculinus (Koch 1844) infestation. The disease probably involves allergic mechanisms and is characterized by erythematous and pruritic skin lesions, widespread hair loss, lymphadenopathy, lymphocytopenia, granulocytosis and wasting. Affected individuals had much reduced numbers of pre-B and B cells in bone marrow and B cells in blood; decreased T-cell numbers in peripheral lymphoid organs and blood; hypergammaglobulinaemia with selective increases of IgG1, IgE and IgA, and depletion on IgM and IgG3, the same isotype distribution being detected in splenic plasmocytes; qualitative modifications of the serum antibody reactivity pattern; and increased production of IL-4 with decreased IL-2 production after in vitro polyclonal stimulation of T cells. Taken together, these results suggest that infestation by M. musculinus in BALB/c mice leads to a significant immunological disorder resulting in a T-helper-2 (Th-2) type response, with marked systemic consequences. This pathological condition may thus provide a useful model system for the immunobiological perturbation associated with chronic allergic disease.

Histological evidence for adulticidal effect of low doses of diethylcarbamazine in bancroftian filariasis

The ability of diethylcarbamazine (DEC) to kill adult Wuchereria bancrofti worms was evaluated by examining lymphatic nodules formed after treatment with 4 different treatment schedules of 193 males living in the endemic area of Greater Recife, Brazil. Lymphatic nodules appeared in the spermatic cord or upper extremities in 43 of 138 microfilaraemic individuals, in 3 of 30 amicrofilaraemic patients with filarial disease manifestations, and in 1 of 25 asymptomatic amicrofilaraemic residents of the endemic area treated with DEC. Fourteen of these nodules were surgically removed 10-150 d after the start of treatment. Regardless of the DEC dosage and schedule used, all nodules contained damaged and degenerating adult worms. An exuberant granulomatous process with large numbers of eosinophils and progressive fibrosis gradually developed around the dead parasites. The mechanism(s) by which DEC killed adult W. bancrofti could not be determined.

Murine acariasis: I. Pathological and clinical evidence suggesting cutaneous allergy and wasting syndrome in BALB/c mouse

We describe here a disease related to mite-associated ulcerative dermatitis in BALB/c mice, a strain previously classified as resistant to this condition. The disease was recognized by pruritic cutaneous pathology and wasting. Pathologic studies showed a marked allergic-type inflammation in the skin. The dominant histologic feature was extensive mast cell infiltration in cutaneous lesions and in lymphoid tissues, associated with a greatly elevated serum IgE concentration. The disease was secondary to infestation with an acarian ectoparasite Myocoptes musculinus, and seemed to represent an allergic reaction to the parasite-derived substances, with an associated wasting syndrome. This condition may be a useful experimental model for allergic diseases.

Bancroftian lymphangitis in northeastern Brazil: a histopathological study of 17 cases

The histological features in 17 patients (3 males and 14 females) with bancroftian lymphangitis, apparently not associated with lymphadenitis, are described. Degenerative alteration in the worms and a severe inflammatory process were observed in the great majority of the cases. The patterns of tissue reaction varied, including exudative, infiltrative and granulomatous lesions. Eosinophils were present, usually in great numbers. Thirteen out of 14 female subjects showed involvement of the breast lymphatics, and in two of these cases microfilariae were found in addition to adult worms. The breast parenchyma was in general spared. In men, lymphatics of the epididymis were affected; in one case, the patient was submitted for surgical castration for prostatic cancer and intact filarial worms without tissue reaction were incidentally detected in peritesticular lymphatics.

Bancroftian lymphadenopathy: a histopathologic study of fifty-eight cases from northeastern Brazil

Histologic study of Bancroftian lymphadenopathy in 58 patients originating from an endemic area revealed a wide range of tissue reactions to the filarial worms. In seven patients (12.0%), no attendant inflammation or parasite damage was observed. A mild-to-intense nongranulomatous chronic lymphangitis was found in 12 patients (20.7%). Granulomatous reactions with variable composition were the most common pattern observed (37 patients, 63.8%); fibrotic lesions containing calcified worms were present in 13 of these patients. Epithelioid granulomas without worms, associated either with granulomatous reactions to the worms (seven patients) or nongranulomatous lymphangitis (two patients), were also detected. Lymphoid hyperplasia and lymphatic dilation were constant, and eosinophil infiltration was usually remarkable. These findings were compared with those reported from nonendemic populations and emphasize the parallelism between the pathologic findings and the immune responsiveness reported in such patients.

Peeling technique for cataracta secundaria associated with posterior chamber lenses

A new method for removing a secondary cataract with a posterior chamber lens in situ was developed using a specially designed irrigation/aspiration handpiece. In two cases, a focal rupture of the posterior capsule without vitreous prolapse occurred. There were no other serious complications observed in 367 patients who were treated.

[Clinical use of a simplified suction-irrigation system for extracapsular cataract extraction]

This paper discusses the clinical application of a simplified irrigation-aspiration system for extracapsular cataract extraction. This simplified apparatus represents a reasonably-priced alternative to the existing expensive and complicated systems. When the surgeon has gained sufficient practice in the use of this method it is a useful complement to the expensive electronic systems.