Infectious disease: changing antibiotic susceptibility

The field of ophthalmology is fortunate to have an array of antibiotics to treat bacterial infections. Because many of the older antibiotics are no longer useful for treating systemic infections, their use and associated acquired resistance have been reduced. These antibiotics, therefore, likely will continue to be effective for treating ophthalmic infections. The bacteria that cause recurrent infections (e.g., blepharitis) may acquire antibiotic resistance because of the repeated use of one particular agent for therapy (e.g., erythromycin). Recurrent pathologies and those that are treated with antibiotics that have varied broadspectrum activities should be cultured routinely to confirm infection and to institute appropriate therapy. Resistant trends of Staphylococcus aureus to the second-generation fluoroquinolones have been confirmed, and new trends of resistance for Pseudomonas aeruginosa have emerged. These antibiotics are effective but should be used judiciously to avoid bacterial resistance to them and to ensure their future potency.     

Computer-aided surgical planning in the treatment of soft-tissue sarcoma

INTRODUCTION

Soft-tissue sarcoma resections are often highly complex procedures that demand meticulous pre-operative planning in order to maximise the potential for complete excision with clear margins, while preserving vital neurovascular structures and muscle groups.

SUBJECTS AND METHODS

We present a computer-aided model for surgical planning using Microsoft Powerpoint as a tool for cross referencing magnetic resonance images and normal anatomical diagrams.

RESULTS

Using this system the operator follows a sequence of pre-planned steps, minimising intra-operative decision making and unexpected adverse events. Four case studies are discussed.

CONCLUSIONS

The visual plan optimises the potential to meet surgical and oncological goals, and serves as an excellent nct to the operation note for documentation of the procedure.     

Hypoxanthine as a graft ischemia marker stimulates catalase activity in the renal vein during reperfusion in humans

BACKGROUND: The impairment of organ function derived from ischemia-reperfusion injury is still an important problem in solid organ transplantation. Cell alterations induced by ischemia prime the tissue for subsequent damage occurring during the reperfusion phase. Purine nucleotides and oxypurines are products of adenine nucleotide degradation. Reperfusion and reoxygenation are characterized by great production of reactive oxygen species and free radicals. On the contrary, superoxide dismutase, catalase, glutathione, and glutathione peroxidase are involved in protecting against free radicals. The aim of the study was to examine the correlation between concentrations of ischemia markers (hypoxanthine or inosine) and the activity of erythrocyte superoxide dismutase, catalase, or glutathione peroxidase. PATIENTS AND METHODS: The study included 40 renal transplant recipients. Before anastomosis of the kidney vessels with the recipient's iliac vessels, a "0" blood sample was taken from the iliac vein. Then, after anastomosis, the renal vein of the graft was cannulated and blood samples I, II, and III were obtained. The reperfusion of the transplanted kidney was measured with a thermovision camera ThermaCAM SC500. RESULTS: The plasma concentrations of hypoxanthine and inosine increased in statistically significant fashion immediately after total tissue reperfusion (P < .0001). Catalase activity at 4 minutes after total tissue reperfusion correlated positively with hypoxanthine concentrations immediately after total tissue reperfusion (Rs = +0.49), 2 minutes after total tissue reperfusion (Rs = +0.47), and 4 minutes after total tissue reperfusion (Rs = +0.46). There were no statistically significant correlations between hypoxanthine or inosine concentrations or superoxide dismutase or glutathione peroxidase activities. CONCLUSIONS: The results of the present study suggest that catalase activity may correlate with the concentration of hypoxanthine in the graft renal vein and other mediators of oxidative stress.     

Efficacy of topical cidofovir on multiple adenoviral serotypes in the New Zealand rabbit ocular model

PURPOSE: The goal of the present study was to determine the efficacy of topical 0.5% cidofovir twice daily for 7 days on the replication of multiple adenovirus (Ad) serotypes of subgroup C (Ad1, Ad5, Ad6) in the New Zealand rabbit ocular model. METHODs: In duplicate experiments for each serotype, a total of 20 rabbits (Ad5) or 16 rabbits each (Ad1 and Ad6) were inoculated topically in both eyes, with 1.5 X 10(6) pfu/eye of the appropriate virus. Twenty-four hours later, the rabbits in each serotype group were randomly divided into two topical treatment groups: I, 0.5% cidofovir; II, control vehicle. Treatment was twice daily for 7 days. All eyes were cultured for virus on days 0, 1, 3, 4, 5, 7, 9, 11, and 14. RESULTS: Compared to the control, treatment with 0.5% cidofovir reduced the following: mean Ad titer (days 1 to 7) for Ad1 (6.3 +/- 20 x 10(1) versus 2.5 +/- 3.9 X 102 pfu/ml; P < 0.0003), Ad5 (3.4 +/-5.8 x 102 versus 1.6 +/- 2.0 x 10(3) pfu/ml; P < 0.000001), and Ad6 (1.2 +/- 5.1 x 10(2) versus 5.5 +/-14 x 10(2) pfu/ml; P = 0.015); reduced Ad-positive eyes/total for Adl [45/128 (35%) versus 84/128 (66%); P = 0.000002], Ad5 [84/160 (53%) versus 131/152 (86%); P < 0.000001], and Ad6 [36/128 (28%) versus 82/128 (64%); P < 0.000001]: and reduced the duration of Ad shedding forAdl (4.9 +/-1.9 versus 9.3 +/- 3.3 days; P < 0.00007), Ad5 (6.4 +/- 2.8 versus 11.5 +/- 2.3 days; P < 0.0001), and Ad6 (4.4 +/- 2.1 versus 8.4 +/- 2.5 days; P < 0.00004). CONCLUSIONS: Topical 0.5% cidofovir twice daily for 7 days demonstrated significant antiviral activity against multiple adenoviral serotypes (Ad1, Ad5, and Ad6) in the New Zealand rabbit ocular model. These in vivo data expand in vitro studies indicating the efficacy of cidofovir against different adenovirus serotypes and support its use in clinical trials.