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Biomedical subjects

Thomas J Liesegang

Publications and source records attributed to Thomas J Liesegang.

At least 19 recordsLinked to original sources
PubMed2005

The Open Access initiative in scientific and biomedical publishing: fourth in the series on editorship.

PURPOSE: To provide basic information about the Open Access concept and its historical development, define the benefits and challenges inherent in this new model, and identify the value of the traditional print model and its movement towards more open access. DESIGN: Review of current information on the subject from numerous sources. METHODS: Medline search and Internet search engines on the topic of Open Access Publishing. RESULTS: The Open Access initiative derives from several premises: medical libraries can no longer afford journal subscriptions; society benefits from the open exchange of ideas; society has in large part already paid for this research; the Internet provides an available venue. The traditional journal publishers model, however, has functioned well over many years with a robust peer review system and increasing Internet digital components permitting search and cross referencing, including elements of the Open Access model. CONCLUSIONS: It will be difficult to maintain the costs of both the traditional journal system and the fully implemented Open Access model. Any decisions that are made must ensure that the archive of prior medical knowledge is not lost, that financial barriers do not restrict publication, and that research continues to be available to those who need it, in the media that they prefer.

Access to Information↗
PubMed2005

Chlamydia conjunctivitis and central retinal vein occlusion.

PURPOSE: To report a case of coexistent Chlamydia conjunctivitis and central retinal vein occlusion (CRVO) in which both problems improved significantly after oral doxycyline. DESIGN: Interventional case report. METHODS: A healthy 39-year-old man presented with follicular and papillary conjunctivitis, unresponsive to topical antibiotic therapy, and a CRVO. The patient had serum IgG titers of 1:256 to both Chlamydia pneumonia and Chlamydia trachomatous. RESULTS: Treatment with oral doxycyline (100 mg orally twice daily for 2 weeks) resulted in complete resolution of the conjunctivitis and rapid improvement of the CRVO. CONCLUSIONS: Because of its ability to cause chronic vascular endothelial infection and localized inflammation, Chlamydia has been implicated in the development of arterial vascular disease. The positive Chlamydia serology, conjunctivitis, CRVO, and excellent response to doxycycline in this patient suggest that Chlamydia may have contributed to his vascular occlusion. Further studies investigating a possible association between Chlamydia and CRVO may be indicated.

Administration, Oral↗
PubMed2005

Survey of ophthalmologists about ocular toxoplasmosis.

PURPOSE: To investigate the number of patient visits to ophthalmologists in the United States that are associated with ocular toxoplasmosis, and to assess ophthalmologists' knowledge and treatment practices with regard to the disease. DESIGN: Written survey. METHODS: A random sample of 1000 US ophthalmologists was surveyed by mail in early 2002 by a questionnaire that was developed to collect information about physician demographics, and with regard to toxoplasmosis, number of patients seen, management practices, and knowledge about pathogenesis and risk factors. RESULTS: Among 478 respondents (48%), 261 (55%) indicated that they had seen one or more patients thought to have active toxoplasmic retinochoroiditis in the prior 2 years, and 445 (93%) indicated that they had seen one or more patients with inactive retinochoroidal scars thought to be inactive toxoplasmosis in the prior 2 years. There was a diversity of opinions regarding topics, including the timing of infection and risk factors for ocular involvement. Many ophthalmologists expressed uncertainty about questions regarding the disease. CONCLUSIONS: Ocular toxoplasmosis is associated with a substantial number of patient visits in the United States each year. A variable understanding of the disease indicates a need for continuing medical education regarding ocular toxoplasmosis.

Chorioretinitis↗
PubMed2004

Herpes zoster virus infection.

PURPOSE OF REVIEW: The virology, pathophysiology, and treatment of the varicella zoster virus (VZV) have been investigated for many years now. Infection with VZV has different ramifications for people of different ages and immune status. The various aspects of VZV disease make it difficult to treat. Selected aspects of VZV disease that pertain to ocular disease are presented. RECENT FINDINGS: The risk factors for VZV disease in the different age spectrums and with concomitant immunodeficiencies have been further clarified. Studies suggest that the VZV may persist for prolonged periods on the cornea after herpes zoster ophthalmicus (HZO). Herpes Simplex Virus (HSV) or VZV may cause many cases of idiopathic uveitis with sectoral iris atrophy. The different patterns of retinal disease caused by VZV may relate to the immune status. Systemic antiviral medications for herpes zoster should be instituted within 72 hours of the rash but could be used later. Systemic antivirals combined with systemic corticosteroids improve the early quality of life in HZ patients. Postherpetic neuralgia is not prevented by early systemic antivirals or corticosteroids. Present systemic antivirals are all effective, but Famvir offers the best dosing schedule. The VZV vaccine is effective but there are some issues that suggest the need for a different vaccination regimen. SUMMARY: Further research must be performed on the clinical and therapeutic aspects of the VZV disease. Although both the vaccine and systemic antivirals have brought tremendous improvements, the disease persists. Therapy lessens but does not eliminate many of the complications. The disease may manifest in unpredictable patterns in this era of vaccination.

Antiviral Agents↗
PubMed2002

Physiologic changes of the cornea with contact lens wear.

PURPOSE: This article reviews the corneal changes resulting from the hypoxia that occurs during sleep and specifically during contact lens wear. METHODS: Discussion includes a literature review and observations regarding the changes to the corneal epithelium, stroma, and endothelium that take place during sleep and wearing of contact lenses made from different materials. RESULTS: Hypoxia and hypercapnia cause significant changes to the corneal epithelium, stroma, and endothelium. Some of these changes can also be seen following the sleep cycle. Epithelial changes include decreased metabolic rate, morphologic changes, microcysts, changes in junctional integrity, decreased corneal sensation, and pannus formation. Stromal changes include stromal edema, stromal acidosis, neovascularization, and changes in corneal shape and, ultimately, corneal thinning. Endothelial changes include bleb formation, polymegethism, changes in endothelial cell density, and possible changes in endothelial function. CONCLUSIONS: There are multiple and significant corneal changes resulting from hypoxia and hypercapnia. These changes vary with the specific lens style. The high-oxygen-permeable contact lenses recently introduced may overcome some of these problems.

Contact Lenses↗