Biomedical subjects
I Ashkenazi
Publications and source records attributed to I Ashkenazi.
Diurnal rhythm of prostanoid secretion from bone/marrow organ in the rat.
The secretion of prostanoids from an adult diaphysial rat bone organ was assessed throughout a 24 h period at 4 h intervals as well as the 24 h activities of bone alkaline phosphatase isoenzyme and serum corticosterone levels. Femurs were removed from 16 rats at each interval and incubated in the absence or presence of indomethacin (100 micrograms). The levels of prostaglandin E2 (PGE2) prostaglandin F2 alpha (PGF2 alpha), and the stable metabolites of thromboxane and prostacyclin, thromboxane B2 (TxB2), and 6-keto prostaglandin F1 alpha (6-keto PGF1 alpha) were measured by radioimmunoassay (RIA). The patterns for each of the variables was subjected to cosinor analysis for predetermined various periods. The chronograms obtained indicated that PGF2 alpha, PGE2, and TxB2 showed 24 h rhythms with computed peak hour acrophases at 1700, 1800, and 2200 h, respectively, and prostacyclin demonstrated a 19 h rhythm with a peak secretion at 1100 h. Corticosterone levels and bone alkaline phosphatase isoenzyme activity in the serum were at peak at 1630 and 2200 h, and at nadir at 0500 and 1000 h, respectively, both exhibiting 24 h rhythms similar to those of PGF2 alpha, PGE2, and TxB2. Bone alkaline phosphatase isoenzyme activity in the femurs' incubation media showed a 12 h diurnal rhythm with peaks at 1230 and 2330 h and nadirs at 0600 and 2330 h (p < 0.01). In summary, this study demonstrated for the first time a 24 h rhythm of prostanoid secretion from diaphysial bone.(ABSTRACT TRUNCATED AT 250 WORDS)
Patient dissatisfaction after functionally successful conjunctivodacryocystorhinostomy with Jones tube.
Conjunctivodacryocystorhinostomy with a Jones tube is an accepted procedure for the treatment of epiphora resulting from obstructed canaliculi. Because of our clinical impression that a high rate of functional success after surgery is associated with a lower rate of patient satisfaction, we analyzed the results and patient satisfaction of 121 patients who underwent conjunctivodacryocystorhinostomy with Jones tubes. The surgical success rate was 92.6% (112 of 121 patients). However, 13 of 112 patients (11.6%) whose operation was functionally successful were not satisfied and 36 of 112 patients (32%) reported having more complications than expected. The highest rate of dissatisfied patients occurred in patients 70 years of age or older (ten of 46 patients, 22%) and in patients 19 years of age or younger (one of four patients). Thus, the indication for conjunctivodacryocystorhinostomy in these age groups should be limited to exceptionally remarkable symptomatic cases. The drawbacks of the procedure should be explained to all candidates to minimize dissatisfaction resulting from unrealistic expectations.
[Ocular metastatic carcinoma--rare or common?].
Ocular metastatic carcinoma is the most common malignant neoplasm of the eye. It usually occurs after diagnosis of the primary tumor and the appearance of metastatic disease. However, it may be the initial manifestation of disease. Subclinical disease is often unnoticed because patients usually have metastatic disease to other organs which dominate the clinical picture. Regardless of the primary tumor, the prognosis following metastasis to the eye or orbit is poor, with average survival only a few months. The most common part of the eye involved by metastases is the highly vascular choroid, followed by the anterior segment, other orbital structures, lids, and retina. Early diagnosis and local treatment of the lesion maximize quality of life, but do not increase survival time.
Exploding bottles: eye injury due to yeast fermentation of an uncarbonated soft drink.
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Proximity-sensor dimmer device as an aid in the reduction of operating microscope-induced retinal phototoxicity.
The length of exposure to the light source of the operating microscope is a major factor determining retinal phototoxicity. In our experience, for about 20% of the time during cataract surgery, the surgeon is not looking through the oculars. To take advantage of these times, we designed a device, a proximity switch consisting of an infrared sensor mounted between the oculars in the operating microscope. When the surgeon's forehead approaches the microscope to look through the oculars, the sensor increases the illumination; when the surgeon moves away, it is automatically reduced. The resulting decreased overall exposure to light may reduce retinal phototoxicity.
[Acanthamoebic keratitis].
Acanthamoebic keratitis is still a rare infection. It occurs in contact lens-wearers, especially when saline is prepared at home from contaminated tap water. There are periods of remission, and occasionally misleading findings resembling those of herpetic keratitis, which make the diagnosis difficult. The isolation of the acanthamoeba is not easy and special culture media are required. Early recognition and aggressive therapy with antiamebic medication and epithelial debridement, often in conjunction with penetrating keratoplasty, are needed. We describe the clinical course, laboratory diagnosis and treatment of 3 patients with acanthamoebic keratitis, 2 men aged 20 and 25, respectively and a women aged 42.
Optic nerve compression by carotid arteries in low-tension glaucoma.
Low-tension glaucoma (LTG) is manifested by glaucomatous optic nerve damage and visual field loss despite normal intraocular pressure (IOP). We describe 62 patients with classical signs of LTG. Computed tomography (CT) was performed in all patients. In 56 of the patients (90.3%), pathology of the intracavernous carotid arteries adjacent to the intracranial opening of the optic canal could be demonstrated. In 28 patients (45.2%) a clear asymmetry of the optic nerve cupping was found and could be correlated with the severity of the carotid artery pathology. A control group of 24 age-matched patients included five (20.8%) with intracavernous carotid artery calcification and only one (4.2%) with intracavernous ectasia. We suggest that calcification, dilatation and ectasia of the carotid artery into the optic canal may play an important role in the pathogenesis of many cases of LTG. The close proximity of the carotid artery to the optic nerve at this location may result in compressive neuropathy with subsequent glaucomatous damage of the optic nerve head.
Major depressive episode secondary to antiglaucoma drugs.
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Suggested mechanism for acute transient myopia after sulfonamide treatment.
This report describes the occurrence of acute transient myopia in a patient treated with sulfonamide. We followed this patient by performing A-scan ultrasonographic ocular measurements documenting the anterior chamber depth, lens thickness, and axial length during the acute and convalescent periods. The outstanding feature in this case was the documented ultrasonographically significant reduction of the anterior chamber depth combined with lens thickening. This could be caused by a forward displacement of the lens as a result of allergic ciliary body edema and rotation. These changes could explain the mechanism of drug-induced transient myopia.
[Considerations in the selection of corneal graft donors before corneal transplantation].
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[Chronobiology in medicine: new concepts in understanding and treatment of disease].
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[Guidelines for selecting sunglasses].
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Corneal graft rejection after neodymium-yttrium-aluminum-garnet laser posterior capsulotomy.
Neodymium-yttrium-aluminum-garnet (Nd-YAG) laser capsulotomy was performed in three patients with corneal graft. Acute corneal graft rejection was noted in these patients 4 weeks to 4 months after posterior capsulotomy. In one patient, enlargement of the capsulotomy opening was followed by a second episode of corneal graft rejection. We discuss the complications of Nd-YAG laser capsulotomy, and its possible role as a cause for corneal graft rejection.
Self-inflicted ocular mutilation in the pediatric age group.
Three mentally retarded children with severe self-inflicted ocular injuries are presented. All three suffered from severe ocular injuries including retinal detachment resulting in progressive visual loss and even blindness. Self-inflicted injuries to the eyes, including self enucleation, is an extremely uncommon form of behavior, rarely encountered by pediatricians. The risk of ocular morbidity is high if the diagnosis is overlooked. Technical advances in ophthalmology permit much improvement in some formerly hopeless cases of ocular self-mutilation, but there is still no accurate method to repair destroyed retinal or nervous tissue. Early identification of patients at risk of ocular self-mutilation is essential in order to prevent or minimize such severe ocular injuries.
Silicone oil-induced corneal hydrops?
A 27-year-old man with a personality disorder, who did not have keratoconus previously, recently presented with a clinical picture resembling acute corneal hydrops OS three years after silicone oil injection for a complicated retinal detachment. Although self-induced trauma could not be excluded completely, this case might represent a newly described late corneal complication of intracameral silicone oil.
Small-incision manual extracapsular cataract extraction using selective hydrodissection.
Hydrodissection is a technique in which balanced salt solution is injected through a cannula into various layers of a cataractous lens to separate the lens lamella in a nonspecific location. Selective hydrodissection allows separation of the lens lamella at different desired anatomical layers. The technique allows the smallest possible nucleus, ie, the hard-core nucleus, to be hydroexpressed as a separate entity, requiring, correspondingly, a relatively small capsulorhexis and limbal incision. Then, in a second maneuver, the epinucleus, which engulfs the hardcore nucleus to form the adult nucleus, also can be aspirated or hydroexpressed as a whole. Selective hydrodissection permits scleral incision and stitchless surgery in planned extracapsular cataract extraction and also may serve as an intermediate step for surgeons who wish to convert to or learn phacoemulsification techniques.