Functional analysis of the amino acids in the DNA recognition alpha-helix of the human thyroid hormone receptor

The roles in DNA binding and transcriptional activation of individual amino acids in the putative recognition alpha-helix of the first zinc finger of the beta-isoform of the human thyroid hormone receptor (hT3R beta) have been probed by site-directed mutagenesis. Alanine substitutions of highly conserved residues involved in the folding of this zinc finger abolished the binding of hT3R beta to various thyroid response elements. A similar effect was observed for alanine substitutions of those conserved residues in hT3R beta that were expected to make specific contacts to DNA bases common to all hormone response elements. The three P-box amino acids have previously been shown to be essential for discrimination of the base pairs that differ between the DNA binding sites for related steroid/thyroid hormone receptors. In hT3R beta, the P-box residues are E, G, and G; the results of this study show that alanine substitution of the glutamic acid dramatically reduces DNA binding activity by hT3R beta, while the substitution of either glycine has little or no effect on DNA binding. The effects of alanine substitutions on hT3R beta transcriptional activation properties were consistent with the effect of these substitutions on DNA binding properties, with the exception of the second P-box amino acid. T3R beta substituted with alanine at this position is substantially more defective in transcriptional activation than it is in specific DNA binding. These results indicate that there are two separate mechanisms of response element discrimination by P-box amino acids of steroid/thyroid hormone receptors, one which operates at the level of DNA recognition and a second which operates at the level of transcriptional activation.

Tissue specificity and serologic reactivity of an autoantigen associated with autoimmune thyroid disease

A recent report has identified a new autoantigen called D1 that appears to be associated with Graves' ophthalmopathy and is expressed in the thyroid and eye muscle. To better characterize the tissue specificity and disease relevance of this antigen, we evaluated the expression of D1 RNA in various human tissues using a reverse transcriptase polymerase chain reaction assay. These studies indicate a wide tissue distribution of the messenger RNA for this antigen, including the thyroid, eye muscle, parathyroid, spleen, skeletal muscle, and uterus. There were variations in the relative amounts of specific message for D1 in the different tissues, with the uterus, thyroid, and eye muscle having the greatest amount of product per microgram of total RNA. A maltose binding protein-D1 fusion protein was expressed in Escherichia coli, purified, and used to assess serologic reactivity to D1 by Western blot. Autoantibodies to this antigen were noted in 19 of 24 (78%) of Hashimoto's disease patients, 26 of 41 (63%) of Graves' disease patients, and in 9 of 17 (53%) of normal controls. Sixty percent of Graves' disease patients with clinical ophthalmopathy had antibodies to D1, as did 63% of Graves' patients without signs or symptoms of clinical ophthalmopathy. There was no correlation between reactivity to D1 and either clinical measures of hyperthyroidism or antibody titers to thyroid peroxidase or thyroglobulin. The presence of autoantibodies to this antigen in patients with Hashimoto's disease, in Graves' disease patients without ophthalmopathy and in normal controls indicate that serologic recognition of this antigen is not restricted to patients with ophthalmopathy. In addition, the expression of messenger RNA for this antigen in multiple types of cells questions the tissue specificity of this autoantigen.

AIDS prevention programs in a smaller community

This paper discusses the development and implementation of an AIDS prevention program in a non-urban area. A non-urban area provides challenges, issues and barriers not found in a large urban area. Characteristics of smaller centre residents, their attitudes and values will shape their response to HIV/AIDS issues. To facilitate HIV service delivery and program implementation, a variety of strategies to facilitate "ownership" are required to create a supportive, caring environment for families affected or infected by AIDS within small community settings.

Tension pneumoorbitus

Posttraumatic tension orbitus developed in a young man causing subconjunctival emphysema and proptosis. Intraocular pressures were monitored as a means of indirectly measuring intraorbital pressure. The patient was serially examined for evidence of compressive optic neuropathy. Because of the possibility of orbital pressure increasing several hours from the time of injury, we recommend monitoring of these patients through intraocular pressure measurement and evaluation of the optic nerve for evidence of compression. Our findings, however, do support previous documentation that the intraocular pressure rise following orbital trauma with orbital emphysema is usually not of sufficient severity or duration to result in visual compromise.

Acute dacryoadenitis and Crohn's disease: findings and management

Concurrent orbital pseudotumor and Crohn's disease, although rare, have been described. To the best of our knowledge, pseudotumor isolated to the lacrimal gland (dacryoadenitis) with concurrent Crohn's disease has never been reported. We present the clinical course and ultrasonographic and radiologic findings of an acute case of isolated bilateral lacrimal gland pseudotumor in a patient with Crohn's disease. The treatment and review of the literature are discussed.

Orbital diagnosis and imaging

A myriad of imaging modalities now exists to aid in the diagnosis of orbital disease. Most of the recent advances in orbital diagnosis are based on refinements of established techniques, although several represent the application of new technology. Invasive techniques, such as orbital arteriography and venography, have been supplanted with computed tomography, which has become the mainstay of orbital diagnosis. The use of magnetic resonance imaging in the assessment of orbital pathology has also increased. Color Doppler, a recent development in ultrasonography, has now been applied to the eye and orbit.

Chromatographic and mass spectrometric methods for determination of lysergic acid diethylamide (LSD) and metabolites in body fluids

Continued illicit use of the potent psychedelic drug lysergic acid diethylamide (LSD) has stimulated efforts to develop effective analytical methods for detection of the drug and its metabolites in body fluids from suspected LSD users. Recently reported methods based on gas and liquid chromatography, combined with single- and multiple-stage mass spectral analysis, now permit accurate detection and quantitation of LSD at sub-nanogram/milliliter concentrations.

Determination of lysergic acid diethylamide (LSD), iso-LSD, and N-demethyl-LSD in body fluids by gas chromatography/tandem mass spectrometry

Procedures for detection and quantitation of lysergic acid diethylamide (LSD), iso-LSD, and N-demethyl-LSD by capillary chromatography/tandem mass spectrometry (GC/MS/MS) are presented. Several methods for derivatization, sample introduction, and ionization, in combination with mass spectrometry/mass spectrometry (MS/MS), have been evaluated for overall ionization efficiency and product-ion sensitivity and specificity. Fragmentation pathways derived from low-energy collision-induced dissociation (CID) spectra of protonated LSD, and the protonated trimethylsllyl derivatives of LSD (LSD-TMS) and deuterium-labeled analogs of LSD, have been proposed. Principal dissociations primarily involve the amide and piperidine-ring moieties in which losses of CH3 radical, CH3NH2, CH3NCH2, diethylamine, diethylformamide, and N,N-diethylpropenamide from MH+ are observed. Positive-ion ammonia chemical ionization and subsequent MS/MS analysis of the protonated molecules (MH+) of the trimethylsilyl (TMS) derivatives of LSD, iso-LSD, and N-demethyl-LSD provide a high degree of specificity for identification of these compounds in urine or blood at low-pg/mL concentrations. Negative-ion chemical ionization and GC/MS/MS analysis of the molecular anion (M-) of the trifluoroacetyl (TFA) derivative is well suited for trace-level identification of N-demethyl-LSD, a metabolite of LSD.

Extrascleral malignant melanoma

We present two cases of anterior extrascleral extension of malignant melanoma in eyes previously blind from other causes. In both cases, the tumor was not detected by the physician but rather by the patient himself (case 1) or his wife (case 2). In one case, the tumor became manifest more than 60 years after the eye became blind from trauma. Although blind eyes may harbor lethal tumors and, therefore, need regular examinations, this simple part of the physical examination frequently remains neglected by ophthalmologists as well as by primary care physicians. We wish to emphasize the potential life-saving importance of regular examinations of blind eyes.

Oculocardiac reflex in the anophthalmic socket

The oculocardiac reflex occurred in a patient with an anophthalmic socket undergoing surgery for inferior fornix shortening and laxity of the lower lid. This reflex occurs only rarely in anophthalmia; it has not been previously reported during socket surgery.

Management of eyelid trauma

The management of eyelid trauma presents some frustrating challenges to the general ophthalmologist. Because each case is unique, adaptation of general principles is essential for optimal ophthalmic treatment. This review includes the essentials of approaches to the evaluation and treatment of eyelid margin and canalicular lacerations. Specific attention is directed towards avoidance of complications.

Argon laser versus thermal cautery for punctal occlusion. An animal study

A subset of the dry-eye patient group manifests their problem so severely that permanent punctal occlusion is required. The technique most often used today is thermal cautery. In this prospective study, an animal model was developed, and the effectiveness of the argon laser as a primary alternative therapy to thermal cautery was evaluated. Dogs were found to have a punctum similar in shape and location to humans; therefore, they were deemed to be a more appropriate animal model for punctal studies than cats. Both laser and thermal cautery are similarly effective in completely occluding puncta in animals. There was a trend toward greater stenosis with the laser in those puncta that were only partially occluded. In addition, laser punctal occlusion appeared to be less painful than thermal cautery.

Eyelid lipogranuloma after hydraulic oil injury

The cytopathology of a lipogranuloma of external origin is reported in the eyelid of a 32-year-old man excised 1 year following regional exposure to an explosion of hydraulic oil under high pressure. The foreign lipids were still present in chronic lipogranulomas with intercellular lipid-filled cysts surrounded by macrophages and giant cells containing intracellular lipid-filled vacuoles. These indicate efforts in storage and very slow digestion. Secondary fibrosis in the region of the lipogranuloma was an important associated process. In view of the widespread technical use of hydraulic oily fluids under high pressure, it is recommended that these fluids be biodegradable.

Adenovirus E1b-58 kD antigen binds to p53 during infection of rodent cells: evidence for an N-terminal binding site on p53

We show using mild extraction procedures that the p53 proto-oncogene forms a complex with adenovirus 5 E1b-58 kD during infection. These complexes are detected as coimmunoprecipitates from radiolabeled extracts of adenovirus infected cells on SDS-PAGE. Furthermore, adenovirus mutants with defects in E1b-58 kD fail to form complexes, whereas mutants in other early region genes still show evidence of complex. Using a panel of monoclonal antibodies to mouse p53, we show that antibodies reacting with N-terminal epitopes on p53, displace E1b-58 kD. This result suggests that E1b-58 kD binds to an N-terminal region of mouse p53. In addition, in a transient transfection assay in monkey COS cells, we show that an N-terminal deletion mutant of mouse p53 does not bind to E1b-58 kD but wild-type mouse p53 does bind. This result again suggests that E1b-58 kD binds an N-terminal determinant on p53.

Orbicularis oculi muscle in children. Histologic and histochemical characteristics

This is the first study devoted to the histologic and histochemical characteristics of the orbicularis oculi muscle in children to the authors' knowledge. The orbicularis muscle was compared with extraocular, facial, and limb striated muscle. Light microscopy showed the orbicularis oculi muscle to be much smaller and more loosely packed than skeletal limb muscles. It further showed these muscle fibers to have greater variation in fiber size and shape and more endomysial and perimysial connective tissue. Finally, analysis of the histochemical reactions showed the orbicularis oculi had a higher percentage of fast-contracting fibers (Type II). This study establishes the histologic and histochemical standard characteristics for the orbicularis oculi muscle in children. It was found that orbicularis oculi muscles have some histologic and histochemical features in common with other facial muscles and other features in common with extraocular muscles.

E1a revisited: the case for multiple cooperative trans-activation domains

Products encoded in the E1a oncogene of adenoviruses are required to activate transcription of all viral early genes and some cellular genes. A current interpretation of experimental data supports the hypothesis that this "trans-activation" is mediated solely by a block of amino acids known as conserved domain 3, which is unique to the largest E1a protein, while the remaining E1a protein sequences contain discrete domains required for functions other than trans-activation. However, there is also considerable evidence inconsistent with this simple model of E1a structure and function. Both of the major E1a proteins appear to participate in trans-activation by three different types of interaction with cellular transcription factors and other regulatory proteins. In this review we attempt to rationalize the experimental data and provide a more integrated view of E1a structure and function.

E1a-dependent expression of adenovirus genes in OTF963 embryonal carcinoma cells: role of E1a-induced differentiation

Some undifferentiated F9 embryonal carcinoma cells allow adenovirus genes to be expressed independently of the E1a oncogene normally required for their activation; this has been attributed to a cellular equivalent of E1a in F9 cells. However, transcription of all early genes was low in undifferentiated OTF963 embryonic carcinoma cells during the first 48 hr after infection with adenovirus type 5 (Ad5). Transcription then increased to about the level seen 16 hr after infection of cells induced to differentiate by retinoic acid (RA) (referred to as RA-dF9 cells), but this increase did not occur in cells infected by the E1a deletion mutant dl312. Addition of E1a in trans, or of RA, had no immediate effect on viral transcription in OTF963 cells, but viral transcription increased about 48 hr after these additions. Ad5 induced transcription of several differentiation-specific genes in OTF963 cells with about the same kinetics as their induction by RA. These genes were superinduced in RA-dF9 cells by cAMP or infection by adenovirus. We suggest the small amount of E1a produced early in infection of OTF963 cells activates cellular genes, some of which are differentiation specific and required for efficient transcription of viral genes, so that E1a both induces and is induced by differentiation. The simple hypothesis of a cellular equivalent to E1a does not adequately explain the complex interactions between viral and cellular genes in OTF963 embryonic carcinoma cells.

Defective expression of adenovirus genes during early infection of undifferentiated OTF963 embryonal carcinoma cells

Adenovirus infection was compared in F9 (OTF963) cells and cells induced to differentiate with retinoic acid, in order to study expression of early genes under the control of the reported "E1a-like factor" in F9 cells. However, not only was transcription of the viral E1a gene defective in undifferentiated cells but expression of all the other early genes was found to be reduced in OTF963 cells in comparison to differentiated cells. The defect in early gene expression was detected at the level of transcriptional initiation during the first 48 h of infection and resulted in similarly low levels of viral cytoplasmic mRNA and viral protein synthesis. Viral DNA replication was delayed and reduced. After 48 h of infection, the defect in transcription in OTF963 cells of E1a and other early genes was relieved, so that by 72 h postinfection the level of transcription was similar to that 16 h after infection of differentiated cells. At no time did adenovirus early gene expression occur independently of viral E1a. These results suggest limits to the generality and explanatory power of the hypothesis that F9 embryonal carcinoma cells contain an E1a-like factor.

Eye shield for patients undergoing laser treatment

We developed a patient eye shield consisting of a sandwich of polymethylmethacrylate and tinfoil to provide corneal and retinal protection from inadvertent injury during argon, neodymium:YAG, or dye laser treatment. The shield was tested with argon, dye, neodymium:YAG and CO2 lasers. This new eye shield is safe, comfortable, and easy to clean and use.

A comparison of two methods of punctal occlusion

We performed punctal occlusion by thermal cautery on 23 patients (45 sides, 90 puncta). One punctum on the right side was randomly assigned to deep cauterization of the punctum and vertical canaliculus, and the other punctum assigned to cauterization of the punctum only. The two treatments were assigned to the opposite puncta on the left side. One month after cauterization, the puncta that received deep cauterization were significantly more likely to have remained closed than those that received superficial cauterization (P less than .01). Survival analysis over a period of follow-up that exceeded one year after surgery, using time to examination because of a reopened punctum as the endpoint, indicated a long-term advantageous effect of deep over superficial cauterization.

Malignant melanoma of the iris in xeroderma pigmentosum

Xeroderma pigmentosum is an autosomal recessive, precancerous dermatosis caused by defective repair of ultraviolet-damaged DNA. Characterized clinically by progressive cutaneous pigmentary alterations and tumorigenesis, it serves as a model for ultraviolet carcinogenesis. We describe the clinical and histopathologic findings in a 31-year-old woman with xeroderma pigmentosum and a massive iris melanoma of the left eye. Histologic examination following enucleation revealed diffuse iris replacement by spindle and epithelioid cells with extension into the trabecular meshwork. Evidence of direct extraocular extension was absent, and a metastatic evaluation showed no abnormalities. To our knowledge, this is the first reported case of xeroderma pigmentosum complicated by melanoma of the iris. It provides further evidence suggesting a role for sunlight exposure in the pathogenesis of uveal melanoma.

The effect of omitting botulinum toxin from the lower eyelid in blepharospasm treatment

We randomly selected 26 patients with essential blepharospasm to receive either botulinum toxin or saline injection in their lower eyelids to evaluate the necessity of lower eyelid injection to relieve blepharospasm. As diplopia may occur from botulinum toxin injections for blepharospasm, most commonly from injection of the lower eyelid, and surgical relief of blepharospasm is often achieved by excision of only the upper eyelid protractors, omission of toxin from the lower eyelid seemed both desirable and possible. All patients received botulinum toxin in the upper eyelids, above the eyebrows, across the glabella, and near the lateral canthus. Thirteen of 15 patients who received saline in their lower eyelids had relief of spasm, with the same spasm-free interval as those who received toxin. We recommend avoiding injection of toxin in the medial two thirds of the lower eyelid in order to diminish the likelihood of diplopia from inferior oblique muscle paresis.

Invasive squamous cell carcinoma of the conjunctiva presenting as necrotizing scleritis with scleral perforation and uveal prolapse

A 64-year-old white man presented with necrotizing scleritis with scleral perforation and uveal prolapse. Pathologic examination revealed squamous cell carcinoma of the conjunctiva invading adjacent corneal stroma and ciliary body. Invasive squamous cell carcinoma of the conjunctiva is uncommon, and intraocular invasion has rarely been reported in the literature.