Biomedical subjects

W J Lipham

Publications and source records attributed to W J Lipham.

8 recordsLinked to original sources

PubMed2001

Multiple recurrences in malignant peripheral nerve sheath tumor of the orbit: a case report and a review of the literature.

PURPOSE: To report the onset of malignant peripheral nerve sheath tumor of the orbit 8 years after irradiation in a patient with neurofibromatosis type-1. METHODS: Case report of a young man with neurofibromatosis type-1 who received irradiation for presumed bilateral optic nerve and chiasmal gliomas and in whom a malignant peripheral nerve sheath tumor later developed. Exenteration with extirpation of the entire contents of the orbit was performed 6 times. RESULTS: Complete recurrence of the tumor occurred after each surgical procedure until the patient died of malignancy. CONCLUSIONS: Our case underscores the risk of irradiation, especially in children with neurofibromatosis type-1, and emphasizes that radiotherapy should never be given as an empirical therapy. The authors believe that irradiation and neurofibromatosis type-1 may, in combination, pose a significant risk for the development of malignancies. Clear-cut indications and a precise tissue diagnosis are desirable before the initiation of radiotherapy, particularly in the pediatric population. We recommend that if irradiation is necessary in persons with neurofibromatosis type-1, regular follow-up is imperative. In view of the hostile nature of malignant peripheral nerve sheath tumor, early aggressive treatment appears to be the only viable alternative at present.

Child, Preschool↗

PubMed2000

Anterior tarsal V-wedge resection for cicatricial entropion.

PURPOSE: To determine the effectiveness of using a radiofrequency instrument to resect a V-shaped tarsal wedge for the correction of cicatricial upper eyelid entropion. METHODS: Prospective evaluation of 16 upper eyelids of 11 consecutive patients. RESULTS: The operation was successful in all 16 eyelids, with excellent cosmetic and functional outcomes. CONCLUSIONS: Tarsal V-wedge resection is an effective alternative to other complicated techniques in the management of upper eyelid cicatricial entropion.

Adult↗

PubMed2000

Direct internal eyelash bulb extirpation for trichiasis.

PURPOSE: To evaluate the success of internal eyelash bulb extirpation in the management of trichiasis. METHODS: The procedure was performed on 26 consecutive eyelids. RESULTS: Our technique was successful in all cases, with no recurrence of signs or symptoms. CONCLUSIONS: Internal eyelash bulb extirpation is a safe and effective technique to remove trichiatic lashes, while avoiding injury to the conjunctiva.

Eyelashes↗

PubMed1998

Sebaceous gland carcinoma: a subtle second malignancy following radiation therapy in patients with bilateral retinoblastoma.

BACKGROUND: Second primary malignancies are common after bilateral retinoblastoma; their estimated incidence has been as high as 51% 50 years after diagnosis. Fifteen patients who developed sebaceous gland carcinoma after radiation therapy have been reported in the literature, five of whom were treated for bilateral retinoblastoma. METHODS: The authors conducted a retrospective chart review of patients treated for bilateral retinoblastoma at Duke University Medical Center who later developed sebaceous gland carcinoma. RESULTS: This article reports two patients who developed sebaceous gland carcinoma after radiation therapy for bilateral retinoblastoma. CONCLUSIONS: Delay in diagnosis is often associated with sebaceous gland carcinoma. Because high mortality is observed with metastatic disease, the recognition of this association is important for anyone who follows patients with a history of bilateral retinoblastoma or prior cranial radiation therapy.

Adult↗

PubMed1998

Remifentanil prevents an increase in intraocular pressure after succinylcholine and tracheal intubation.

We have studied changes in intraocular pressure (IOP) in 30 patients after succinylcholine (suxamethonium) and tracheal intubation following administration of propofol 2 mg kg-1 and either remifentanil 1 microgram kg-1 (group R) or saline (group S). IOP was measured before induction, before administration of succinylcholine and the study drug, before intubation and for every 1 min after intubation for 5 min. There was a significant decrease in IOP in group R compared with group S from the time of administration of the study drugs to the end of the study (P < 0.006).

Adult↗

PubMed1997

Idiopathic macular hole following vitrectomy: implications for pathogenesis.

BACKGROUND AND OBJECTIVE: Attention to the pathogenesis and clinical features of macular hole formation has increased with the advent of therapy. The purpose of this study is to present three cases that occurred in atypical settings that may have important pathogenic implications. PATIENTS AND METHODS: The authors conducted a retrospective study of three patients who presented with macular holes that developed 10 months to 5.5 years after previous vitrectomy. In each case, the cortical vitreous layer was absent in the region of the macula at the time of operation for the macular hole. RESULTS: The macular hole was successfully sealed and the visual acuity improved in all patients. All three cases in this report lacked an operculum, occurred long after vitreous removal, and had no evidence of any residual cortical vitreous. CONCLUSIONS: Macular hole formation in the absence of cortical vitreous suggests the possibility that the etiology of macular holes may involve a spontaneous umbo dehiscence rather than vitreous-induced surface traction. A mechanism involving a cystic degenerative process is proposed as the cause of atypical and typical macular hole formation.

Aged↗

PubMed1991

Recognition of peptides that are immunopathogenic but cryptic. Mechanisms that allow lymphocytes sensitized against cryptic peptides to initiate pathogenic autoimmune processes.

Interphotoreceptor retinoid binding protein (IRBP) is a glycoprotein that localizes in the retina and induces inflammatory changes in this tissue in immunized animals. Certain IRBP-derived peptide determinants are also immunopathogenic, and we have previously shown that these determinants could be either immunodominant or cryptic. Lymphocytes sensitized against the cryptic peptides do not recognize whole IRBP in vitro, and yet these lymphocytes must recognize the protein in vivo to initiate the autoimmune pathogenic process. We have examined here two hypothetical explanations for this dissociation: 1) It is possible that when IRBP is processed in vitro, immunodominant peptide determinants compete with the cryptic ones and inhibit their interaction with the MHC molecules on the APC. This explanation was ruled out here by the finding that the immunodominant peptide 1179-1191 ("W10") did not inhibit the response to a cryptic one, 1158-1180 ("R4"), when added at equivalent and even moderately higher concentrations. 2) The second hypothesis proposes that the cryptic antigenic sites are not generated from IRBP by the APC in vitro, whereas enzymes in the retina digest the protein to yield fragments that generate these antigenic sites upon processing by the APC. In line with this hypothesis, we have found that cleavage of IRBP by certain endoproteinases (Asp-N, Glu-C, or V-8) produced molecules that were recognized in culture by lymphocytes sensitized to the immunopathogenic but cryptic peptide R4. This study, therefore, describes a putative Ag processing mechanism that results in IRBP recognition and, consequently, the initiation of an autoimmune process by lymphocytes sensitized against a cryptic peptide. Furthermore, experiments with R4 and other cryptic peptides have shown that cleavage fragments of up to 38 residues in length can be presented by APC, to stimulate lymphocytes sensitized against these peptides. No responses were stimulated, however, by fragments of 75 or more residues. The data thus provide new insights into the processing and presentation of cryptic peptide determinants by APC.

Amino Acid Sequence↗

PubMed1990

Immunological features of synthetic peptides derived from the retinal protein IRBP: differences between immunodominant and non-dominant peptides.

Interphotoreceptor retinoid-binding protein (IRBP) is a glycoprotein of 1264 residues (bovine) which localizes specifically in the retina and pineal gland and induces inflammatory changes in these organs (EAU and EAP, respectively) in immunized animals. We report here on differences between the immunological activities in Lewis rats of four IRBP-derived synthetic peptides. Only one of these peptides, designated R14 (residues: 1169-1191) is immunodominant, i.e., it has the capacity to stimulate lymphocytes sensitized against whole IRBP. The remaining peptides, R4 (1158-1180), R8 (1197-1209), and R12 (248-266), are non-dominant and are not recognized by IRBP-sensitized lymphocytes. R14 differed profoundly from the other peptides in its immunogenicity, inducing cellular immunity at the low dose of 0.1 nmol/rat, whereas the non-dominant peptides initiated immune responses at doses approximately 100 times higher. R14 was also superior to the non-dominant peptides in its antigenicity, as determined by the lowest concentration required to induce sensitized lymphocytes to proliferate. Responses were stimulated by R14 at a concentration of 10(-6) microM, while the three non-dominant peptides were stimulatory at the much higher concentration of 10(-1) microM. These data support the concept that immunodominance is linked to a high binding affinity of the peptide determinant to the major histocompatibility complex antigens on antigen-presenting cells.

Amino Acid Sequence↗