Uptake and hydrolysis of sphingomyelin analogues in Plasmodium falciparum-infected red cells.
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4-Chloro-7-nitrobenzofurazan↗
Biomedical subjects
S A Lauer
Publications and source records attributed to S A Lauer.
Ocular adnexal lymphoid tumors.
This year, advances in the management of ocular adnexal lymphoid tumors have been based on the distinction between MALT and non-MALT lymphomas. MALT lymphomas have a more indolent course than non-MALT lymphomas, and in the conjunctiva a more conservative approach can be taken than has been recommended previously. In the orbit the likelihood of progression to systemic disease seems high, even with MALT lymphomas, and treatment with radiation is still recommended in all cases. The REAL classification system has replaced the Rappaport and Lukes-Collins system for classifying ocular adnexal lymphomas. Most ocular adnexal lymphomas are composed of neoplastic B-lymphocytes. Additional cases of T-cell lymphoma involving the orbit and conjunctiva were reported in the literature this past year.
Conjunctival Neoplasms↗
Orbital trauma.
In this review, a number of current issues on the management of orbital trauma are discussed including the indications for orbital exploration in zygomatic complex fractures, the utility of transantral endoscopy in orbital trauma surgery, and preferred implant materials in orbital reconstruction. We emphasize the need for a classification system to define some of the clinical terms used in describing orbital trauma, to improve communication between clinical services, and to standardize the clinical literature on orbital trauma.
Endoscopy↗
Brown's syndrome diagnosed following repair of an orbital roof fracture: a case report.
The upgaze deficit of Brown's syndrome differs from the upgaze deficit of an orbital floor fracture with entrapment. In Brown's syndrome, the upgaze limitation is most evident in adduction of the eye. This difference may be difficult to establish at times, particularly beneath the periorbital edema of an acute traumatic injury. Nevertheless, it is important to recognize this differentiation, since the approach to management of these two clinical entities is distinctly dissimilar. Brown's syndrome is produced by restriction of the superior oblique muscle tendon, usually in the region of the trochlea. In the course of describing a case of Brown's syndrome, recognized following the repair of an orbital roof fracture, issues related to etiology, diagnosis, and management are discussed. In the case presented, surgical repair of the left eye was performed.
Adult↗
A membrane network for nutrient import in red cells infected with the malaria parasite.
The human malaria parasite Plasmodium falciparum exports an interconnected network of tubovesicular membranes (the TVM) that extends from the parasite's vacuolar membrane to the periphery of the red cell. Here it is shown that extracellular solutes such as Lucifer yellow enter the TVM and are delivered to the parasite. Blocking the assembly of the network blocked the delivery of exogenous Lucifer yellow, nucleosides, and amino acids to the parasite without inhibiting secretion of plasmodial proteins. These data suggest that the TVM is a transport network that allows nutrients efficient access to the parasite and could be used to deliver antimalarial drugs directly into the parasite.
Adenosine↗
An immortalized cell culture from a malignant mixed tumor of the lacrimal gland.
Tumor cells from a malignant mixed tumor of the lacrimal gland were maintained in tissue culture for more than 55 generations. Comparative immunohistochemical analysis was performed on whole tumor sections and on the tumor cell culture to define the origin of the cells in culture. The cultured cells expressed cytokeratin, smooth-muscle actin, S-100 protein, and vimentin and were negative for glial fibrillary acidic protein. Tumor sections expressed cytokeratin but were negative for muscle-specific actin, vimentin, and glial fibrillary acidic protein. Through tissue culture studies of salivary gland epithelial neoplasias, which are very similar to lacrimal gland epithelial neoplasias, pluripotential stem cells have been identified. Similar tissue culture analysis of lacrimal gland epithelial neoplasms can be a valuable tool for studying the origin of these uncommon tumors.
Antigens, Neoplasm↗
Classification of orbital floor fractures.
A retrospective series of orbital, axial, and coronal computed tomography scans from 24 orbital floor fractures was studied to define the anatomic location of the fracture. Floor fractures without rim involvement, which are referred to clinically as blowout fractures, were located medial to the infraorbital nerve or extended on both sides of the nerve. Floor fractures with rim involvement were associated with zygomatico-orbital or Le Fort II or III fractures, and were located either lateral to or on both sides of the infraorbital nerve. No blowout fractures were confined to the lateral half of the orbital floor and no floor fractures with rim involvement were confined to the medial half of the orbital floor. The authors propose a classification system for describing orbital floor fractures based on their anatomic location relative to the infraorbital nerve.
Adolescent↗
Sphingolipid synthesis as a target for chemotherapy against malaria parasites.
The human malaria parasite Plasmodium falciparum contains sphingomyelin synthase in its Golgi apparatus and in a network of tubovesicular membranes in the cytoplasm of the infected erythrocyte. Palmitoyl and decanoyl analogues of 1-phenyl-2-acylamino-3-morpholino-1-propanol inhibit the enzyme activity in infected erythrocytes. An average of 35% of the activity is extremely sensitive to these drugs and undergoes a rapid, linear decrease at drug concentrations of 0.05-1 microM. The remaining 65% suffers a slower linear inhibition at drug concentrations ranging from 25 to 500 microM. Evidence is presented that inhibition of the sensitive fraction alone selectively disrupts the appearance of the interconnected tubular network in the host cell cytoplasm, without blocking secretory development at the parasite plasma membrane or in organelles within the parasite, such as the Golgi and the digestive food vacuole. This inhibition also blocks parasite proliferation in culture, indicating that the sensitive sphingomyelin synthase activity as well as the tubovesicular network may provide rational targets for drugs against malaria.
Animals↗
Mesenchymal chondrosarcoma with secondary orbital invasion.
Orbital involvement with mesenchymal chondrosarcoma is rare. Until recently, despite the young age of the affected population, exenteration was the recommended management. We report a patient with orbital invasion by mesenchymal chondrosarcoma managed surgically without exenteration. Adjuvant chemotherapy and radiotherapy were administered. There is no evidence of local or distant tumor recurrence with 30 months of postoperative follow-up. This and other recent case reports suggest that exenteration may not be necessary for local tumor control of mesenchymal chondrosarcoma in the orbit.
Adolescent↗
Orbitocraniofacial gunshot wounds: craniofacial reconstruction and preparation of the anophthalmic socket.
This article is a retrospective clinical and radiographic analysis of four patients who survived high caliber orbitocraniofacial gunshot injuries. Early multidisciplinary craniofacial reconstruction included repair of comminuted orbital fractures with multiple autogenous bone grafts and/or porous polyethylene implants, enucleation, and insertion of a hollow silicone sphere as an anophthalmic socket implant. Migration of the silicone implant occurred in one case, requiring replacement with an autogenous dermis fat graft. There were no cases of extrusion or infection. Socket motility remained limited in all cases, despite reapposition of the extraocular muscles. In two cases with autogenous bone grafts along the orbital roof, there was no radiographic evidence of graft resorption after three years. Soft tissue volume deficiency and superior sulcus deformity developed in the three cases which were followed for more than six months. Despite these limitations, all four patients are wearing comfortable ocular prostheses. The postoperative results support immediate preparation of the anophthalmic socket after craniofacial reconstruction of these injuries.
Adipose Tissue↗
Zygomatico-orbital fractures: historical perspective and current surgical management.
This article presents a general historical review of zygomatico-orbital (ZO) fractures with application of contemporary surgical procedures. Two surgical cases are presented, in which the ZO fractures were approached via a transconjunctival incision with a lateral canthotomy. A two-point rigid internal fixation, combined with a porous high-density polyethylene orbital floor reconstruction, produced uniformly excellent cosmetic and functional results in a total of 42 patients with ZO fractures who were treated over a 2-year period.
Fracture Fixation, Internal↗
Amino acid sequence of the region of beta 2-glycoprotein 1 (gp1) which mediates binding of autoantibodies to the cardiolipin-gp1 complex in humans.
Anticardiolipin antibodies (ACA) in sera from patients with autoimmune and infectious diseases were tested for binding to beta 2-glycoprotein 1 (gp1) in order to determine whether human gp1 acts as a cofactor for the binding of ACA to cardiolipin (CL) or as an antigen recognized by ACA. While none of the ACA-positive sera tested recognized gp1 by itself, gp1 was necessary for the binding of ACA to CL in sera from four patients with autoimmune diseases. In three of the four sera the presence of lupus anticoagulant (LA) was detected by prolonged partial thromboplastin time (PTT). Examinations using the bovine equivalent of human gp1 contained in fetal calf serum (FCS) and adult bovine serum (ABS) showed that the human protein can be replaced by the bovine equivalent in the enzyme-linked immunosorbent assay (ELISA). Using affinity-purified antibodies directed against the CL-gp1 complex it was shown that the binding of these antibodies is dependent on the concentration of the bovine gp1 equivalent contained in the formed complex. Similar results found with the human gp1 confirmed this assertion. In order to find out which region of gp1 might mediate the binding between ACA and cardiolipin, we examined to what extent selected oligopeptide sequences of gp1 can substitute for the protein. Peptide P2 (representing the amino acids at positions 268-278 of the gp1 molecule) and gp1 showed about the same binding capacity. Histidine in this peptide seems to be essential for the binding to CL as we found decreased binding with peptides modified in this position. Conclusions from this work show that gp1 does not act as a relevant antigen for ACA, but occupies an essential function in the complex formed with cardiolipin for a certain group of ACA.
Amino Acid Sequence↗
Recurrent conjunctival papilloma causing nasolacrimal duct obstruction.
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Conjunctival Neoplasms↗
Human papillomavirus type 18 in conjunctival intraepithelial neoplasia.
Human papillomaviruses are oncogenic viruses that have been found in a variety of epithelial neoplasias. We sought to confirm their presence in conjunctival intraepithelial neoplasia. Five tumors were studied with a polymerase chain-reaction assay designed to detect the E6 region of human papillomavirus types 16 and 18. Human papillomavirus type-16 DNA was found in four of the five tumors, including two tumors that contained both type-16 and type-18 DNA. Viral DNA was not present in the fifth tumor.
Autoradiography↗
Orbital T-cell lymphoma in human T-cell leukemia virus-I infection.
This is the first report of orbital involvement in systemic adult T-cell leukemia/lymphoma (ATLL). The etiologic agent of ATLL is the human T-cell leukemia virus-I (HTLV-I), the first retrovirus demonstrated to induce cancer in humans. The diagnosis of ATLL is based on characteristic clinicopathologic features in combination with serologic or virologic evidence of HTLV-I infection. Serum antibodies to HTLV-I were identified by immunofluorescent microscopy. Viral particles characteristic of HTLV-I were found in a culture of the patient's peripheral blood lymphocytes. The patient was a native of the Caribbean, one of the known endemic foci of HTLV-I infection. Adult T-cell leukemia/lymphoma should be considered in the differential diagnosis of orbital T-cell lymphomas.
Adult↗
Leber's optic atrophy with myopia masquerading as glaucoma: case report.
In recent years there has been much discussion in the literature regarding the proper approach to the patient who presents with apparent "low tension" glaucoma. In addition to a complete workup and proper management of such a patient, careful consideration must be given to the differential diagnosis of clinical conditions presenting with optic disc cupping and visual field changes. We present an interesting clinical situation in which a patient with severe myopia and Leber's optic atrophy was referred for surgery for treatment of apparent progressive "low tension" glaucoma.
Adult↗