Herpetic stromal disease: response to acyclovir/steroid therapy

The efficacy of combined acyclovir and steroid therapy in the treatment of herpetic stromal disease was evaluated by clinical evaluation of disease, the rebound of disease following termination of therapy, and the recovery of virus and viral DNA from corneas in a rabbit model. Therapy with acyclovir alone produced a significant reduction in corneal thickness in 10% of eyes. Addition of steroid to acyclovir therapy decreased the severity of stromal disease as measured by corneal thickness and increased the frequency of response to treatment to 63% of eyes. All eyes receiving acyclovir alone experienced rebound of disease following termination of therapy. Combined therapy increased the severity of rebound of corneal disease. Virus was recovered from cell cultures established after recovery from rebound in 50% of untreated and treated eyes. Viral DNA was detected by PCR in five of the nine corneal cultures which did not produce infectious virus.

The occurrence of serum autoantibodies against enolase in cancer-associated retinopathy

Cancer-associated retinopathy (CAR) is an uncommon paraneoplastic disease in which degeneration of the retina occurs as a remote effect of cancer in a distant part of the body. Immunoreactivity of sera from CAR patients and controls have been analyzed. Immunostaining of human retinal proteins showed that a soluble protein of Mr approximately 46 kDa (p46) is labeled by antibodies from several CAR patients with various types of cancer (lung, breast, bladder, prostate, salivary gland, and gastrointestinal tract cancer and chronic lymphocytic leukemia). These sera did not show reactivity with the 23-kDa protein previously associated with CAR. To identify and further characterize p46, the retinal protein was purified to homogeneity by anion-exchange chromatography and preparative gel electrophoresis. Protein sequence analysis of the peptides from p46 revealed a high homology with human enolase, an important glycolytic enzyme. Although enolase has been previously identified as a product of several types of tumors, and enolase activity has been detected in the sera of some cancer patients, the existence of autoantibodies directed to enolase has not been described. This is the first report of the presence of serum antibodies to retinal enolase in the patients with cancer and the CAR syndrome. When antibodies of specific isotypes (IgG, IgM, and IgA) were measured, IgG1 isotype was dominant. The significance of these antibodies for the disease process is under investigation.

Long-term safety of the aminobisphosphonate alendronate in adult dogs. I. General safety and biomechanical properties of bone

Alendronate (4-amino-1-hydroxybutylidene bisphosphonate, ALN) is an aminobisphosphonate that is being developed for the treatment of diseases characterized by increased bone resorption. The purpose of this study was to assess the long-term safety of ALN with special emphasis on bone strength and bone morphology. Thirty-two (16 males and 16 females) 83- to 86-week-old beagle dogs were treated p.o. for up to 3 years with ALN at 0.00, 0.25, 0.5 or 1.0 mg/kg/day. The following parameters of toxicity were assessed: physical signs, body weight, ophthalmology, radiographic evaluation of bone, electrocardiography, hematology, clinical chemistry, urinalysis, necropsy including organ weight assessment, histopathology and biomechanical testing of bone. There were no apparent compound-related alterations in any of the above mentioned parameters except the expected changes (related to the pharmacological activity of ALN) in serum phosphorus and Ca concentrations and in the histology of bones with active endochondral bone formation (rib). There were mild transient reductions in the serum phosphorus and Ca concentrations at the 1.0 mg/kg/day dose level during the early part of the study. There was a dose-dependent delay in bone remodeling in the ribs of all dogs treated with ALN. There was no similar change in the tibia. Most importantly, there were no spontaneous fractures and there were no changes in the structural properties of femoral or vertebral bone. The total ALN content of bone in an average dog (10 kg) after 3 years of treatment with approximately five items of the intended dose for the treatment of osteoporosis was approximately 8 mg, which is only 0.001% of total bone mass (700 g). Introduction.

Endothelial barrier function and Na+/K(+)-ATPase pump density in herpetic stromal disease

PURPOSE

Corneal edema is a significant component of the various forms of herpes simplex virus type 1 (HSV-1)-induced stromal disease. Maintenance of corneal thickness, a reflection of corneal hydration, depends on a physical barrier formed by endothelial cell-cell junctions and by the activity of Na+/K(+)-ATPase pumps that regulate ion flux and thus influence water movement through this cell layer. These functions were measured in corneas with increased corneal thickness caused by HSV-1-induced stromal disease to determine their contribution to the pathogenesis of the edema.

METHODS

Stromal disease with corneal edema was induced in rabbits by intrastromal injection of the RE strain of HSV-1. At various times after infection, during the development of and recovery from stromal disease, endothelial barrier function and Na+/K(+)-ATPase pump sites were measured in excised rabbit corneas.

RESULTS

The endothelial permeability coefficient, Ktrans, for 14C-dextran, 3H-inulin, and 14C-mannitol, were not altered significantly during periods of maximal corneal edema and stromal disease. Endothelial Na+/K(+)-ATPase pump density, as measured by ouabain binding, showed a statistically significant (P < 0.05) decrease in HSV-1-infected corneas during peak edema compared to mock antigen-injected or uninjected control corneas. Pump density returned to baseline values by 24 days after infection, concurrent with the resolution of corneal edema.

CONCLUSIONS

These results indicate that corneal endothelial barrier function was not altered in this form of HSV-1-induced stromal edema; however, pump density was reduced significantly.

Reducing surgical length of stay: quantifying the impact

Length-of-stay (LOS) reduction is a strategy encouraged at all levels of health care to manage within a resource limited environment. However, few organizations have attempted to quantitatively understand the impact of reducing LOS. This study examines the relationship between reducing LOS and cost through a retrospective, medical records analysis of three surgical procedures (appendectomy, cholecystectomy and caesarean section) at an Ontario community hospital Department of Surgery. Hypotheses are presented and a methodology is described. The results are discussed with a focus on the factors that hospitals, administrators and physicians might consider in a LOS reduction program.

Clinical efficacy and safety of low-dose flutamide alone and combined with an oral contraceptive for the treatment of idiopathic hirsutism

BACKGROUND AND OBJECTIVE

High doses of flutamide, which is the only antiandrogen that specifically blocks the androgen receptor, have recently been used with good clinical results in women with hirsutism. Since regression of hair growth requires long-term therapy, clinical and economic considerations are important. The use of the lowest efficacious dosage could reduce costs. This study was undertaken to compare safety and efficacy of a low dose of flutamide (125 mg twice daily) alone and in combination with a triphasic oral contraceptive (OC) in women with idiopathic hirsutism.

PATIENTS

Flutamide was administered orally in a low dose of 125 mg twice daily for 12 months alone in women with no risk of pregnancy or during the use of an oral contraceptive.

MEASUREMENTS

Women were seen every 3 months and were evaluated for hirsutism score, hormone and lipid measurements.

DESIGN

The study, which was conducted as a prospective open trial, was proposed to patients with idiopathic hirsutism, that is, with serum androgen levels in normal range and LH/FSH ratio less than 2.

RESULTS

A statistically significant decrease in hirsutism score as compared to baseline was observed after only 3 months with either treatment, flutamide alone (16.9 +/- 1.6 vs 14.2 +/- 1.7, P < 0.0001) or the combination of flutamide with OC (15.6 +/- 0.8 vs 11.9 +/- 0.8, P < 0.001). Three months after cessation of treatment a statistically significant decrease from baseline was observed in the two groups. Nevertheless, at 6 months post-treatment this decrease was still significant only in the group who took flutamide in combination with an oral contraceptive. Flutamide alone does not appear to modify the levels of lipoproteins. The association of flutamide with a triphasic formulation significantly increased the HDL-C levels.

CONCLUSIONS

This study shows beneficial effects of a low dose of flutamide in women with idiopathic hirsutism. The addition of an oral contraceptive is judicious to prevent pregnancy and reduce recurrence of hirsutism after cessation of flutamide. Peripheral androgenic blockage does not modify lipid profiles and it might reduce the negative effect of oral contraceptive on HDL-C levels. The addition of electrolysis delays the recurrence of hirsutism after cessation of flutamide.

Ventilatory management in critical neurologic illness

Evolution and refinement of airway and ventilatory management has taken place in neurologic critical care. Applications for ventilatory management have been extended to virtually all acute life-threatening illnesses found in neurologic critical care units today. This article focuses on the airway and ventilatory management of patients with acute raised intracranial pressure, cervical spine injuries, and neuromuscular ventilatory failure.

Delivery of DNA into mammalian cells by receptor-mediated endocytosis and gene therapy

The correction of genetically based disorders by the introduction of a therapeutic genetic construct into the appropriate cell type ("gene therapy"), has become a distinct possibility in recent years. In order for gene therapy to be a practical alternative to more conventional pharmaceutical approaches to treatment, it must be administrable in vivo. This demands that a system be developed that can specifically target the DNA to the desired cell type once introduced into the patient. Among the procedures that are currently being pursued, the delivery of DNA to cells by receptor mediated endocytosis (RME), comes closest to fulfilling this crucial requirement. The natural physiological process of RME can be exploited to deliver genetic material to cells. An antibody or ligand to a cell surface receptor that is known to undergo endocytosis, is complexed with DNA through a covalently linked polycationic adjunct (e.g., polylysine, protamines). Such complexes retain their binding specificity to the cell surface and are taken up into the cell where they enter the endosomal compartment via normal endocytotic processes. In addition, steps must be taken to avoid degradation of the DNA within the endosome-lysosome. Cells can be treated with the lysosomatropic agent chloroquine during the transfection procedure. Alternatively, the components of viruses that enter cells by endocysis and possess an endosomal "break out" capacity can be used. Replication defective adenovirus coupled to the ligand-DNA complex gives transfection efficiencies of virtually 100% on tissue culture cells in vitro. Synthetic peptides that mimic the membrane fusing region of influenza virus hemagglutinin, have also been successfully used as part of the ligand-DNA complex to bring about endosomal escape. Preliminary studies have demonstrated the potential of this method to specifically target DNA to the cell type of choice in vivo. Delivery of genes by receptor-mediated endocytosis offers the greatest hope that gene therapy can be an inexpensive, easily applicable, widespread technology.

Fat-suppressed MR of the orbit and cavernous sinus: comparison of fast spin-echo and conventional spin-echo

PURPOSE

To compare T2-weighted fat-suppressed fast spin-echo imaging with fat-suppressed conventional spin-echo imaging in the detection of normal intraorbital and pericavernous anatomy and orbital disease, and to determine the efficacy of fat saturation with T2-weighted fast spin-echo imaging of the cavernous sinus.

METHODS

Contrast-to-noise ratios of normal intraorbital anatomy were calculated and compared in 10 consecutive patients using fat-suppressed fast spin-echo and conventional spin-echo T2-weighted images. Contrast-to-noise ratios of common intraorbital lesions were calculated and compared using fat-suppressed fast spin-echo and fat-suppressed conventional spin-echo. Qualitative evaluation was performed and compared for normal intraorbital anatomy using both fat-suppressed fast spin-echo and fat-suppressed conventional spin-echo in 16 patients. Qualitative evaluation for the detection of normal anatomic structures of the pericavernous region was performed and compared using fast spin-echo with and without fat suppression and fat-suppressed conventional spin-echo T2-weighted images in 16 patients. Fat saturation was performed using standard commercially available chemical saturation technique.

RESULTS

Reduced imaging time allowed more acquisitions for fat-suppressed fast spin-echo images, which significantly improved visibility of intraorbital and pericavernous anatomy over fat-suppressed conventional spin-echo. Anatomic visibility was also improved because of reduced motion, phase encoding, and susceptibility artifacts. There was no significant difference between contrast-to-noise ratios for fat-suppressed fast spin-echo and fat-suppressed conventional spin-echo imaging of the lateral and medial rectus muscles. Contrast-to-noise ratios of fat suppressed fast spin-echo of orbital disease was significantly greater than contrast-to-noise ratios of fat-suppressed conventional spin-echo. Detection of several normal anatomic structures of the pericavernous region was significantly improved with non-fat-suppressed fast spin-echo over fat-suppressed fast spin-echo because of significantly reduced magnetic susceptibility artifact.

CONCLUSIONS

Fat-suppressed fast spin-echo is superior to fat-suppressed conventional spin-echo for T2-weighted orbital imaging. Non-fat-suppressed fast spin-echo is the preferred pulse sequence for T2-weighted imaging of the cavernous sinus because of the minimal susceptibility artifact.

Reversals of blood-brain barrier disruption by catalase: a serial magnetic resonance imaging study of experimental optic neuritis

PURPOSE

To investigate serially the role of catalase detoxification of endogenous H2O2 in the disruption of the blood-brain barrier (BBB) and demyelination of experimental optic neuritis.

METHODS

Serial contrast-enhanced magnetic resonance imaging (MRI) of the optic nerves (T1 weighted) and T2 weighted MRI without contrast were performed on 18 guinea pigs 3 to 14 days after sensitization with central myelin for experimental allergic encephalomyelitis. Sex and age-matched littermates were paired and sensitized with the identical antigenic emulsion. To detoxify endogenous hydrogen peroxide (H2O2), animals received daily intraperitoneal injections of polyethylene glycol (PEG)-catalase at a dose of 12,000 U/kg per day for 3 days, then 1,200 U/kg daily for the next week, commencing 3 days after antigenic sensitization. Littermates received an equal volume of preservative-free saline. The intensity of gadolinium-DTPA (Gd-DTPA) enhancement was quantitated by obtaining the value for a region of interest (ROI) of the right optic nerve and the left optic nerve. The effect of H2O2 detoxification by catalase was evaluated by differences in the intensity of Gd-DTPA enhancement and T2 weighted signal in the ROI of the right and the left optic nerves at 7, 10, and 14 days after antigenic sensitization, from the pretreatment value obtained at day 3. The effectiveness of catalase detoxification of H2O2 was assessed with quantitative ultracytochemical localization of electron-dense, H2O2-derived cerium perhydroxide in the optic nerves.

RESULTS

With PEG-catalase treatment, mean differences for Gd-DTPA enhancement in the ROI at 7, 10, and 14 days after antigenic sensitization were significantly reduced from the pretreatment values obtained 3 days after antigenic sensitization compared with the comparable interval values for untreated littermates. For T2 weighted signal intensity, only the 7- and 14-day values were significantly less with PEG-catalase compared with values for littermates obtained at comparable intervals. Quantitative ultracytochemical localization of H2O2-derived cerium perhydroxide reaction product revealed significant reductions in the medium number of cerium particle counts of the optic nerve head, sheath, and myelinated retrobulbar nerve.

CONCLUSIONS

PEG-catalase reduced H2O2-derived cerium perhydroxide reaction product in the optic nerve but did not eliminate it, reversed disruption of the BBB as measured by Gd-DTPA enhancement, and reduced demyelination and edema as measured by T2 weighted signal intensity, suggesting detoxification of H2O2 as a new treatment strategy for disorders of primary demyelination of the central nervous system.

Regulation of herpes simplex virus thymidine kinase in cells treated with a synergistic antiviral combination of alpha interferon and acyclovir

Alpha interferon (IFN-alpha) and acyclovir (ACV) are synergistic in their anti-herpes simplex virus activities. IFN-alpha treatment reduced the herpes simplex virus thymidine kinase (TK) activity present in cells 6 h postinfection, while steady-state levels of TK mRNA remained at or above the amount in infected, untreated cells. The inhibition of TK production by IFN-alpha treatment appeared to be transient and translational, not transcriptional.

Disruption of the blood-brain barrier in experimental optic neuritis: immunocytochemical co-localization of H2O2 and extravasated serum albumin

PURPOSE

To probe the role of endogenous hydrogen peroxide (H2O2) in the pathogenesis of disruption of the blood-brain barrier (BBB) associated with experimental allergic encephalomyelitis (EAE), an animal model for primary central nervous system demyelination.

METHODS

Strain-13 guinea pigs were sensitized for EAE with central myelin in complete Freund's adjuvant. Magnetic resonance imaging with Gd-DTPA was performed twice a week for 2 weeks to assess disruption of the BBB, in vivo, by the enhancement of the optic nerves. Two weeks after antigenic sensitization, ultracytochemical localization of endogenous H2O2 was performed using the cerium perhydroxide method, with co-localization of endogenous serum albumin extravasation using gold-labeled antibodies against serum albumin. Examination of blood vessels for perivascular immunogold-labeled serum albumin and H2O2 derived reaction product began in the optic nerve head and proceeded toward the retrobulbar optic nerve until a total of 20 vessels were evaluated per animal.

RESULTS

Magnetic resonance imaging revealed Gd-DTPA enhancement of the optic nerves in all animals sensitized for EAE. Optic nerve ultrastructure revealed colloidal gold-labeled antibodies against serum albumin in the perivascular and adjacent interstitial spaces of capillaries and small venules in which H2O2 derived cerium perhydroxide reaction product was also simultaneously evident. Immunogold-labeled serum albumin was predominantly confined to the intravascular compartment of the optic nerve in the absence of perivascular H2O2 and/or perivascular foci of inflammatory cells. The difference between the mean percentage of blood vessels (61.8%) with co-localization of perivascular immunogold-labeled serum albumin and cerium perhydroxide reaction product, to the mean percentage of blood vessels (9.5%) with perivascular immunogold-labeled serum albumin in the absence of cerium perhydroxide, was statistically significant (P = 0.0019).

CONCLUSIONS

Endogenous H2O2, found at the foci of BBB disruption, may be one of the mediators involved in the alteration of vascular permeability in experimental optic neuritis.

A randomized, double-blind, placebo-controlled study on the effect of conjugated estrogens on skin thickness

OBJECTIVE

Our purpose was to assess the potential benefit of therapy with conjugated estrogens therapy on skin thickness in postmenopausal women.

STUDY DESIGN

Sixty postmenopausal women were randomly allocated to receive conjugated estrogens or placebo treatment for 12 months. Neither participants nor investigators were aware of the group allocation. Skin thickness was measured by ultrasonography at baseline and after 6 to 12 months of treatment. Histologic changes were evaluated by skin biopsy at baseline and after 12 months' treatment. Quality of life and adverse events were recorded at each visit and at the end of treatment.

RESULTS

Treatment with conjugated estrogens for 12 months significantly increases, at the level of the right great trochanter, the thickness of the skin (p < 0.01), as assessed by ultrasonography, and of the dermis (p < 0.05), as assessed by skin biopsy. No statistically significant difference was observed in the control population. Quality of life was reported to be improved (p < 0.05) in women treated with estrogen compared with those in the placebo group.

CONCLUSION

The results may help postmenopausal women to better appraise the benefits of estrogen replacement therapy, and they provide further evidence of the potential of conjugated estrogens in preventing skin aging.

Evaluation of anterior segment tolerance to short-term intravitreal perfluoron

PURPOSE

A study was performed to evaluate corneal and anterior segment toxicity from short-term (24-hour) intravitreal use of perfluoro-n-octane.

METHODS

Forty aphakic, vitrectomized eyes of pigmented rabbits underwent intravitreal injection of either 0.5 ml of perfluoro-n-octane (Perfluoron; Infinitech, St. Louis, MO; treated) or 0.5 ml balanced saline solution (control). Perfluoron was allowed to remain in the vitreous cavity for 24 hours. Serial measurements of corneal pachymetry and pneumotonometry were performed at 1, 4, 12, and 24 hours after injection. After 24 hours, endothelial cell morphology and barrier function were evaluated.

RESULTS

No significant differences in corneal thickness or intraocular pressure were noted between the two groups at any of the time points studied, and no differences in endothelial cell density/hexagonality or endothelial cell barrier function were observed 24 hours after injection.

CONCLUSIONS

In the absence of sustained corneal contact, no evidence of significant acute corneal or anterior segment toxicity was observed in response to short-term intravitreal perfluoro-n-octane in aphakic, vitrectomized rabbit eyes.