Bowel perforation in intestinal lymphoma: incidence and clinical features

BACKGROUND

Perforation is a serious life-threatening complication of lymphomas involving the gastrointestinal (GI) tract. Although some perforations occur as the initial presentation of GI lymphoma, others occur after initiation of chemotherapy. To define the location and timing of perforation, a single-center study was carried out of all patients with GI lymphoma.

PATIENTS AND METHODS

Between 1975 and 2012, 1062 patients were identified with biopsy-proven GI involvement with lymphoma. A retrospective chart review was undertaken to identify patients with gut perforation and to determine their clinicopathologic features.

RESULTS

Nine percent (92 of 1062) of patients developed a perforation, of which 55% (51 of 92) occurred after chemotherapy. The median day of perforation after initiation of chemotherapy was 46 days (mean, 83 days; range, 2-298) and 44% of perforations occurred within the first 4 weeks of treatment. Diffuse large B-cell lymphoma (DLBCL) was the most common lymphoma associated with perforation (59%, 55 of 92). Compared with indolent B-cell lymphomas, the risk of perforation was higher with aggressive B-cell lymphomas (hazard ratio, HR = 6.31, P < 0.0001) or T-cell/other types (HR = 12.40, P < 0.0001). The small intestine was the most common site of perforation (59%).

CONCLUSION

Perforation remains a significant complication of GI lymphomas and is more frequently associated with aggressive than indolent lymphomas. Supported in part by University of Iowa/Mayo Clinic SPORE CA97274 and the Predolin Foundation.

Lenalidomide can be safely combined with R-CHOP (R2CHOP) in the initial chemotherapy for aggressive B-cell lymphomas: phase I study

Lenalidomide was shown to have significant single-agent activity in relapsed aggressive non-Hodgkin's lymphoma (NHL). We conducted a phase I trial to establish the maximum tolerated dose of lenalidomide that could be combined with R-CHOP (rituximab-cyclophosphamide, doxorubicin, vincristine, and prednisone). Eligible patients were adults with newly diagnosed, untreated CD20 positive diffuse large cell or follicular grade III NHL. Patients received oral lenalidomide on days 1-10 with standard dose R-CHOP every 21 days. All patients received pegfilgrastim on day 2 of the cycle and aspirin prophylaxis. The lenalidomide dose levels tested were 15, 20 and 25 mg. A total of 24 patients were enrolled. The median age was 65 (35-82) years and 54% were over 60 years. Three patients received 15 mg, 3 received 20 mg and 18 received 25 mg of lenalidomide. No dose limiting toxicity was found, and 25 mg on days 1-10 is the recommended dose for phase II. The incidence of grade IV neutropenia and thrombocytopenia was 67% and 21%, respectively. Febrile neutropenia was rare (4%) and there were no toxic deaths. The overall response rate was 100% with a complete response rate of 77%. Lenalidomide at the dose of 25 mg/day administered on days 1 to 10 of 21-day cycle can be safely combined with R-CHOP in the initial chemotherapy of aggressive B-cell lymphoma.

The absolute monocyte and lymphocyte prognostic score predicts survival and identifies high-risk patients in diffuse large-B-cell lymphoma

Despite the use of modern immunochemotherapy regimens, almost 50% of patients with diffuse large-B-cell lymphoma will relapse. Current prognostic models, including the International Prognostic Index, incorporate patient and tumor characteristics. In contrast, recent observations show that variables related to host adaptive immunity and the tumor microenvironment are significant prognostic variables in non-Hodgkin lymphoma. Therefore, we retrospectively examined the absolute monocyte and lymphocyte counts as prognostic variables in a cohort of 366 diffuse large-B-cell lymphoma patients who were treated between 1993 and 2007 and followed at a single institution. The absolute monocyte and lymphocyte counts in univariate analysis predicted progression-free and overall survival when analyzed as continuous and dichotomized variables. On multivariate analysis performed with factors included in the IPI, the absolute monocyte and lymphocyte counts remained independent predictors of progression-free and overall survival. Therefore, the absolute monocyte and lymphocyte counts were combined to generate a prognostic score that identified patients with an especially poor overall survival. This prognostic score was independent of the IPI and added to its ability to identify high-risk patients.

A phase II trial of the oral mTOR inhibitor everolimus in relapsed aggressive lymphoma

The phosphatidylinositol 3-kinase signal transduction pathway members are often activated in tumor samples from patients with non-Hodgkin's lymphoma (NHL). Everolimus is an oral agent that targets the raptor mammalian target of rapamycin (mTORC1). The goal of this trial was to learn the antitumor activity and toxicity of single-agent everolimus in patients with relapsed/refractory aggressive NHL. Patients received everolimus 10 mg PO daily. Response was assessed after two and six cycles, and then every three cycles until progression. A total of 77 patients with a median age of 70 years were enrolled. Patients had received a median of three previous therapies and 32% had undergone previous transplant. The overall response rate (ORR) was 30% (95% confidence interval: 20-41%), with 20 patients achieving a partial remission and 3 a complete remission unconfirmed. The ORR in diffuse large B cell was 30% (14/47), 32% (6/19) in mantle cell and 38% (3/8) in follicular grade 3. The median duration of response was 5.7 months. Grade 3 or 4 anemia, neutropenia and thrombocytopenia occurred in 14, 18 and 38% of patients, respectively. Everolimus has single-agent activity in relapsed/refractory aggressive NHL and provides proof-of-concept that targeting the mTOR pathway is clinically relevant.

CD20-targeted measles virus shows high oncolytic specificity in clinical samples from lymphoma patients independent of prior rituximab therapy

New therapeutic modalities for B-cell non-Hodgkin's lymphomas (B-NHL) are needed, especially for relapsing and aggressive subtypes. Toward this end, we previously generated a fully CD20-targeted and armed measles virus, and tested its efficacy in a xenograft model of mantle cell lymphoma (MCL). Here, we quantify its spread in peripheral blood mononuclear cells and/or tissue of patients with different histological subtypes of B-NHL, including splenic marginal zone lymphoma (SMZL). CD20-targeted MV efficiently infects lymphoma cells from SMZL and MCL while sparing most cells in the CD20-negative population, in contrast to the parental vaccine-lineage MV, which infects CD20-positive and CD20-negative cells equally. Rituximab therapy (4-8 months before relapse) did not interfere with the infectivity and specificity of MV(green)H(blind)antiCD20 in patient lymphoma samples. Thus, CD20-targeted oncolytic virotherapy is likely to be effective after previous antiCD20 therapy.

Taxonomic features of seven serotypes of simian and ape foamy viruses

Two new simian viruses were recovered from squirrel monkeys and galagos. They possess foamy virus group properties which appear distinct from other virus groups. Serologically they were designated types 4 and 5 and are completely specific from each other and from types 1, 2, 3, 6, and 7 by neutralization tests. The study includes a comparison of the properties of all seven types in one laboratory.

Low risk of symptomatic venous thromboembolic events during growth factor administration for PBSC mobilization

The use of erythropoietic agents has been associated with an increased risk of venous thromboembolic events (VTEs), especially in patients with underlying malignancies. However, it is not known whether there is an increased risk of VTE associated with granulocyte growth factors. We reviewed 621 patients undergoing PBSC mobilization using granulocyte growth factors, alone or in combination with CY. Patients with a diagnosis of AL amyloidosis (AL: 114; 18%), multiple myeloma (MM: 278; 44%) Hodgkin lymphoma (HL: 20; 3%) or non-Hodgkin lymphoma (NHL: 209; 33%) were included. Symptomatic VTE occurred in six (0.97%) patients: two AL, two MM and two NHL. Of the six patients, two had pulmonary embolism, one developed deep vein thrombosis and three developed symptomatic catheter related thrombosis. Two patients with AL had heparin-induced thrombocytopenia and thrombosis. We found a low incidence of VTE among patients undergoing PBSC mobilization.

Salvage chemotherapy with rituximab, oxaliplatin, cytosine arabinoside, and dexamethasone (ROAD) in patients with relapsed CD20+ aggressive B-cell lymphoma

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Background: In the original PARMA trial it was demonstrated that salvage chemotherapy with DHAP followed by autologous bone marrow transplant resulted in increased overall survival over salvage chemotherapy with DHAP alone in patients with aggressive lymphomas. The current study was designed to assess safety and feasibility of ROAD as a salvage chemotherapy regimen which could be administered as an inpatient or outpatient. Methods: Patients received immunochemotherapy on the following schedule: rituximab 375 mg/m2 weekly × 4, oxaliplatin 130 mg/m2 on day 2, Ara C 2000mg/m2 x 2 doses on day 2 and dexamethasone 40 mg on days 2–5, with OAD repeated at 3 week intervals (up to 6 cycles). Patients were considered for autologous stem cell transplantation after 2 cycles if eligible. Eligible histologies included diffuse large B cell lymphoma, mantle cell lymphoma and transformed lymphoma in first relapse. Results: 50 patients were accrued from Aug 2006 through Jul 2008: 5 patients were deemed ineligible after central pathology review. Baseline characteristics of eligible patients included median age 69 (range 23 - 77), 53% were male, 53% had advanced stage at relapse, LDH was elevated in 58% and all patients had an ECOG PS of 2 or less. Patients received a median of 2 cycles of therapy (range 1–6) with 39/45 receiving treatment in cycle 2, with 12 patients continuing beyond 2 cycles. 31 patients experienced grade III/IV hematologic toxicity and 22 patients had grade III/IV non-hematologic toxicity, primarily febrile neutropenia. One patient developed grade III nephrotoxicity due to disease progression. Twenty patients received their treatments exclusively as outpatients. 26 responses were seen in the 45 eligible patients (58%, 95% CI: 44–74%), with 20 responding patients proceeding to autologous SCT. Conclusions: ROAD is a safe and effective salvage chemotherapy regimen for relapsed aggressive lymphoma, including as a preparatory regimen prior to stem cell transplant. It appears to have similar response rates to R-DHAP in a similar patient population, but without the potential nephrotoxicity (data from prior published study from NCCTG). ROAD can be safely administered as an inpatient or outpatient.

No significant financial relationships to disclose.

Phase II trial of the oral mTOR inhibitor everolimus (RAD001) for patients with relapsed or refractory lymphoma

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Background: mTOR inhibition with intravenous temsirolimus (Wyeth Pharmaceuticals) has been associated with responses in mantle cell lymphoma (J Clin Oncol 23;5347, 2005) as well as other lymphomas (Blood 108 (11) 2483; 2006). This phase II study tested the oral mTOR inhibitor everolimus (RAD001, Novartis Pharmaceuticals) in three simultaneous two-stage phase II lymphoma studies - aggressive (group 1), indolent (group 2), or uncommon (group 3). The goals were to learn the toxicity profile and to assess the anti-tumor response. Planned interim analysis for groups 1 and 3 have been completed and are the subject of this report. Methods: Patients (pts) received 10 mg PO daily for each 28 day cycle (up to 12) and restaged after 2, 6, and 12 cycles. The primary endpoint is the confirmed response rate, including CR, CRu or PR. 12 pts were enrolled in stage 1 of each study. At least 1 success in 12 is required to proceed to stage 2, to a total of 37 pts. Overall, the treatment will be considered promising if 4 or more successes are observed in all 37 pts in each group. Results: The median age of the 12 pts in group 1 was 68.5 yrs (range: 53–80), with a median of 3 (range, 1–15) prior therapies. Four pts had a prior stem cell transplant (SCT). Pts completed a median of 7 (range, 1–12) cycles of therapy. 6 confirmed responses have been achieved (1 CR, 5 PR), meeting the overall criteria for promising results in this study. Common grade 3 adverse events (AEs) include thrombocytopenia (3 pts) and anemia (2 pts). For group 3, the median age was 49 yrs (range, 27–78), with a median of 7 (range, 1–13) prior therapies and 6 pts had a prior SCT. Pts have completed a median of 6.5 cycles (range, 1–11). 5 confirmed responses have been achieved (5 PR), meeting the criteria for this regimen to be considered promising. Of these 5 patients, 3 had HD, 1 T-cell NHL, and 1 had macroglobulinemia. Common grade 3 AEs include anemia (3 pts) and thrombocytopenia (2 pts). No grade 4 AEs were reported. Conclusions: Oral everolimus has activity in a spectrum of lymphomas with acceptable toxicity. The responses observed in both group 1 and group 3 met the criteria to continue accrual. These results provide the rationale for additional studies with this novel class of agents and to integrate mTOR inhibitors into salvage treatment regimens.

No significant financial relationships to disclose.

Intraocular use of rituximab

PURPOSE

To evaluate the toxicity of 1 mg of intraocular rituximab and to present a small case-series of patients treated with intravitreal rituximab.

METHODS

Rituximab (1 mg/0.1 ml) was injected in the vitreous of one eye of three Dutch-belted rabbits. Two animals were injected with balanced salt solution as controls. At 1 month the rabbits were killed and the eyes examined by light microscopy. Three patients (five eyes) with intraocular lymphoma were also treated with a 1 mg injection of rituximab.

RESULTS

The treated rabbit eyes and the control eyes showed no light microscopic evidence of ocular toxicity at 1 month following injection. The five human eyes of three patients have shown no evidence of intraocular toxicity with a median follow-up time of 3.6 months (range 2.0-6.4 months). One patient received a total of four injections in the right eye and three injections in the left eye.

CONCLUSION

Intravitreal rituximab at a dose of 1 mg does not appear to cause toxicity in rabbit eyes and in the five eyes of three patients.

Early lymphocyte recovery after autologous stem cell transplantation predicts superior survival in mantle-cell lymphoma

Autologous stem cell transplantation (ASCT) is an effective treatment strategy for mantle-cell lymphoma (MCL) demonstrating significantly prolonged progression-free survival (PFS) when compared to interferon-alpha maintenance therapy of patients in first remission. The study of absolute lymphocyte count at day 15 (ALC-15) after ASCT as a prognostic factor in non-Hodgkin lymphoma (NHL) included different lymphoma subtypes. The relationship of ALC-15 after ASCT in MCL has not been specifically addressed. We evaluated the impact of ALC-15 recovery on survival of MCL patients undergoing ASCT. We studied 42 consecutive MCL patients who underwent ASCT at the Mayo Clinic in Rochester from 1993 to 2005. ALC-15 threshold was set at 500 cells/microl. The median follow-up after ASCT was 25 months (range, 2-106 months). The median overall survival (OS) and PFS times were significantly better for the 24 patients who achieved an ALC-15 >or=500 cells/microl compared with 18 patients with ALC-15 <500 cells/microl (not reached vs 30 months, P<0.01 and not reached vs 16 months, P<0.0006, respectively). Multivariate analysis demonstrated ALC-15 to be an independent prognostic factor for OS and PFS. The ALC-15 >or=500 cells/microl is associated with a significantly improved clinical outcome following ASCT in MCL.

Autologous stem cell transplant for primary CNS lymphoma results in prolonged progression free and overall survival

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Background: Survival for patient with primary CNS lymphoma (PCNSL), in general, is poor with patients requiring frequent chemotherapy treatments or receiving whole-brain radiation therapy, which can potentially result in significant neurologic decline and dementia. Because of the improved survival of high risk patients with aggressive lymphoma undergoing autologous stem cell transplant (ASCT), we began ASCT for patients with PCNSL in first or later remission with chemotherapy sensitive disease. We now report on outcomes of patients who have had at least 1 year follow up post ASCT. Methods: Between June, 2000 and September, 2004, 11 patients underwent ASCT for PCNSL. The medical records of consenting patients were abstracted for the following information. Median age at transplant was 47 years old (range 30–67). Median number of prior treatments 1 (range 1–3). Median time from diagnosis to transplant was 7.5 months (range 2.9 to 75.8). Median International Extranodal Working Study Group Prognostic Score: 2 (range 0–3). Disease status at transplant: First CR 5 patients, later CR or PR 6 patients. Results: Eleven patients underwent ASCT for PCNSL and have a minimum of 1 year follow-up. All patients received BEAM conditioning. Median follow up was 28.3 months. Four patients have relapsed at a median of 200 days (range 40–523). Of the patients who relapsed, one has died of disease progression and the remaining three are alive after additional therapy. Median overall survival and progression free survival from transplant have not been reached. Two year overall and event free survival are 89% and 61%, respectively. Conclusions: Although limited by patient selection and retrospective biases, this review suggests that ASCT for PCNSL demonstrates improved overall survival when compared to historical controls with similar PCNSL Prognostic Scores (2 year survival for patients from diagnosis with PS 2–3 was 48% in a prior published study). ASCT in first remission in patients with PCNSL appears promising and may limit the need for additional therapy which can be myelosuppressive or result in neurologic decline.

No significant financial relationships to disclose.

Absolute lymphocyte count prior to rituximab therapy predicts time to progression in patients with follicular grade 1 lymphoma

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Background: The immunologic mechanisms of action of rituximab have been described as complement mediated lysis, vaccine like effect, antibody-dependent cellular cytotoxicity (ADCC) and the cellular microenvironment. We hypothesized that in the treatment of follicular grade 1 lymphoma (FL), the presence of a stronger host immune status prior to rituximab therapy would result in a prolonged time to progression (TTP). As a surrogate marker for immune status, we evaluated the absolute lymphocyte count (ALC) prior to rituximab treatment. Methods: Between 1996 and 2002, 1,104 consecutive FL patients were evaluated at Mayo Clinic Rochester. Of these patients, we retrospectively analyzed a group of all FL patients who received rituximab (375 mg/m2 once a week for four weeks) alone at any time during their lymphoma treatment at the Mayo Clinic (n=79). The primary end-point was to assess the impact of ALC just prior to rituximab therapy on TTP for FL. Results: The median age of the cohort was 56.6 years (range: 25–98 years). The median follow-up was 12.5 months (range: 1–76 months). An ALC count of ≥ 890 cells/μL prior to rituximab therapy predicted a longer TTP compared with an ALC < 890 cells/μl (25 months versus 8 months, respectively, p < 0.0124). A higher complete response rate was observed in the ALC ≥ 890 cells/μL group compared with the ALC < 890 cells/μL group [15/40 (38%) vs 5/39 (13%), p < 0.035]. The groups were balanced regarding the Follicular Lymphoma International Prognostic Index (FLIPI) (p = 0.794). Multivariate analysis demonstrated ALC ≥ 890 cells/μL prior to rituximab therapy as an independent prognostic factor for TTP when compared to hemoglobin, LDH, and Ann Arbor stage. The ALC was independent of the FLIPI in multivariate analysis. Conclusions: This data supports the hypothesis that a higher lymphocyte count, as a marker of the immune status of the patient, predicts for a longer TTP following rituximab therapy.

No significant financial relationships to disclose.

Mutations within the putative membrane-spanning domain of the simian immunodeficiency virus transmembrane glycoprotein define the minimal requirements for fusion, incorporation, and infectivity

The membrane-spanning domain (MSD) of a number of retroviral transmembrane (TM) glycoproteins, including those from the human and simian immunodeficiency viruses (HIV and SIV), have been predicted to contain a charged arginine residue. The wild-type SIV TM glycoprotein is 354 amino acids long. The entire putative cytoplasmic domain of SIV (amino acids 193 to 354) is dispensable for virus replication in vitro, and such truncation-containing viruses are capable of reaching wild-type titers after a short delay. We show here that further truncation of eight additional amino acids to TM185 results in a protein that lacks fusogenicity but is, nevertheless, efficiently incorporated into budding virions. By analyzing a series of nonsense mutations between amino acids 193 and 185 in Env expression vectors and in the SIVmac239 proviral clone, a region of the SIV TM that contains the minimum requirement for glycoprotein-mediated cell-to-cell fusion and that for virus replication was identified. Virus entry and infectivity were evident in truncations to a minimum of 189 amino acids, whereas cell-cell fusion was observed for a protein of only 187 amino acids. Glycoprotein was efficiently incorporated into budding virions in truncations up to 185 amino acids, indicating that such proteins are membrane anchored and are transported to the cell surface. However, truncation of the TM to 180 amino acids resulted in a protein that displays a transport defect and may be retained in the endoplasmic reticulum. Based on our analyses of these mutants, an alternative model for the MSD of SIV is proposed. Our model suggests that membrane-imbedded charged residues can be neutralized by side-chain interactions with lipid polar head groups. As a consequence, the membrane-spanning region can be reduced by more than a helical turn. This new model accounts for the ability of truncations within the predicted MSD to remain membrane anchored and maintain biological activity.

Transport of a lysosomally targeted Rous sarcoma virus envelope glycoprotein involves transient expression on the cell surface

The details of intracellular transport pathways for glycosylated proteins remain incompletely described. We previously described a mutant Rous sarcoma virus envelope glycoprotein (gp), mu 26, with an altered membrane-spanning domain that was targeted to lysosomes after traversing the trans-Golgi. This mutant protein was not detectable on the cell surface by immunofluorescence, but its pathway for degradation remained unclear. To investigate this we have employed a second env mutation, S19, that results in a protein which is defective for normal cleavage/activation by intracellular enzymes, but remains susceptible to cleavage by extracellular proteases. Cleavage/activation of the double mutant by trypsin, which could only occur if it was exposed on the cell surface, was observed, indicating that the plasma membrane is an intermediate destination in the transport of this mutant protein. To substantiate these results, cells expressing the mu 26 glycoprotein were incubated with an antibody specific for the native protein in the presence of chloroquine. The specific accumulation of this antibody/gp complex in vesicles, as detected by internal immunofluorescence, confirmed the trypsin cleavage results. We conclude that this rapidly degraded mutant protein is transported from the trans-Golgi to the cell surface, where it is only transiently exposed, and then rapidly endocytosed and lysosomally degraded. The relevance of these results to the targeting of lysosomal proteins is discussed.

Treatment and long-term follow up of a capillary angioma of the optic disc

This case report describes the treatment of a capillary angioma involving the temporal aspect of the optic disc by photocoagulation therapy. It chronicles the effect of creating a retinal-choroidal adhesion at the temporal margin of the lesion in reducing exudation from the angioma spreading to involve the macula. The patient in question has been followed for sixteen years and vision in this eye has been maintained at 6/6 following the course of therapy described. Our experience suggests that direct laser treatment to capillary angiomas of the optic disc combined with photocoagulation barrier protection of the macula is beneficial and should be considered early when the lesion is relatively small.

Is genetic predisposition an important risk factor in age-related macular degeneration?

Age-related macular degeneration (ARMD) is the most common cause of visual morbidity in the aged in the Western world. The aetiology of ARMD is unknown. Although clinicians have noted that ARMD demonstrates a familial tendency, the question regarding the role of hereditary factors in ARMD remains unanswered. The aims of this study were to assess the level of genetic input into ARMD and to assess the mode of inheritance of the disease. Fifty affected patients and 50 age- and sex-matched controls and their immediate families were invited to take part in the study. Thirty-six patients, controls and their families were studied. Eighty-one siblings of affected patients and 78 control siblings were available. Twenty of the 81 affected siblings were found to suffer from ARMD. In contrast only 1 of 78 control siblings had ARMD. This was statistically significant. The results confirm that hereditary factors are important in the aetiology of ARMD.

Expression and characterization of glycophospholipid-anchored human immunodeficiency virus type 1 envelope glycoproteins

Four chimeric human immunodeficiency virus type 1 (HIV-1) env genes were constructed which encoded the extracellular domain of either the wild-type or a cleavage-defective HIV-1 envelope glycoprotein (gp160) fused at one of two different positions in env to a C-terminal glycosyl-phosphatidylinositol (GPI) attachment signal from the mouse Thy-1.1 glycoprotein. All four of the constructs encoded glycoproteins that were efficiently expressed when Rev was supplied in trans, and the two cleavable forms were processed normally to gp120 and a chimeric "gp41." The chimeric glycoproteins, in contrast to the wild-type glycoprotein, could be cleaved from the surface of transfected cells by treatment with phosphatidylinositol-specific phospholipase C, indicating that they were anchored in the plasma membrane by a GPI moiety. These GPI-anchored glycoproteins were transported intracellularly at a rate only slightly lower than that of the full-length HIV-1 glycoprotein and were present on the cell surface in equivalent amounts. Nevertheless, all four glycoproteins were defective in mediating both cell-cell and virus-cell fusion as determined by syncytium formation in COS-1-HeLa-T4 cell mixtures and trans complementation of an env-defective HIV-1 genome.

Truncations of the simian immunodeficiency virus transmembrane protein confer expanded virus host range by removing a block to virus entry into cells

We have investigated how truncation of the cytoplasmic domain of the transmembrane (TM) glycoprotein of simian immunodeficiency virus (SIV) modulates the host range of this virus. Termination codons were introduced into the env gene of SIVmac239 which resulted in the truncation of the transmembrane protein from a wild-type 354 amino acids (TM354) to 207 (TM207) and 193 (TM193) amino acids. Expression of the wild-type and mutant env genes from a simian virus 40-based vector resulted in normal biosynthesis and processing of the glycoproteins to gp130 and gp41 or the truncated TM proteins (gp28 and gp27). When expressed on the surface of COS-1 cells, all three glycoproteins mediated fusion of both CEMX174 and HUT78 cells. Virions containing the wild-type and mutant glycoproteins were capable of efficient replication in macaque peripheral blood lymphocytes and CEMX174 cells; in contrast, only virions that contained TM207 were capable of rapid infection of HUT78 cells. Both truncated glycoproteins were capable of efficiently mediating infection of both CEMX174 and HUT78 cells by an env-deficient human immunodeficiency virus. The wild-type SIV glycoprotein, however, was unable to mediate human immunodeficiency virus infection of HUT78 cells when assayed with this system. An analysis of the protein composition of SIV released from infected CEMX174 cells showed that the mutant virions contained significantly higher levels of glycoprotein compared with the wild type. These results demonstrate that truncation of the SIV cytoplasmic domain removes a block at the level of glycoprotein-mediated virus entry into HUT78 cells and points to a role for glycoprotein density in determining virus tropism.

Peripapillary subretinal neovascular membranes: the natural history

We studied the natural course of peripapillary subretinal neovascular membranes in 20 eyes. The membranes were either idiopathic in nature or associated with underlying disease. We found that the visual prognosis was related to the behaviour of the membrane and to the patient's age. Patients under the age of 40 years had unilateral disease and a more favourable visual prognosis. Older patients had a uniformly poor visual prognosis and a high incidence of bilateral disease. Fifty-four per cent of patients over 45 years and 62% over 70 years of age had bilateral membranes. In those over the age of 70 years, 75% of untreated eyes lost vision to a level of 3/60 or less in both eyes. The probability of the second eye becoming involved in the older group of patients was 62%. The period of time elapsing between involvement of the first and second eye varied between simultaneous occurrence and a delay of 7 years.

Ocular siderosis

The authors report their experience in the management of 8 patients with ocular siderosis due to a retained intraocular foreign body (IOFB). All patients were male, aged between 19 and 39 years. Seven had a definite history of trauma; 3 had presented at the time of injury to a casualty department, and the diagnosis had been missed. The interval between injury and diagnosis ranged from 2 to 24 months. IOFB removal was performed in 7 patients: through a sclerotomy and magnet or foreign body forceps in 4 eyes and via a pars plana vitrectomy and intraocular foreign body forceps in 3 eyes. Cataract extraction was performed in 4 patients. Histological examination of specimens removed at the time of surgery showed iron deposition in the conjunctiva, anterior lens capsule and pars plana. Transmission electron microscope X-ray microanalysis showed that iron was contained in siderosomes, intracytoplasmic membrane-bound dense bodies. Final visual acuity was 6/12 or better in 6 patients and reduced to light perception in the remaining 2 due to proliferative vitreoretinopathy.

Cornea plana and sclerocornea in association with recessive epidermolysis bullosa dystrophica. Case report

We report a case of bilateral cornea plana and sclerocornea in a 14-year-old boy with recessive epidermolysis bullosa dystrophica. This is the first reported association of these anomalies. Bilateral cataracts were present at initial presentation. These spontaneously reabsorbed over the subsequent 18 months.

Metastatic disease from untreated choroidal and ciliary body melanomas

We report the case histories of three patients with untreated malignant melanoma of the choroid or ciliary body. Metastatic disease which resulted in death was diagnosed four years in two patients and 13 years in one patient after the diagnosis of choroidal melanoma was suspected. The diagnosis of malignant melanoma was confirmed by histopathology in two of these patients.

Traumatic retinal detachment

Seventy-seven patients developed retinal breaks following an episode of ocular contusion, and 65 (84.4%) of these developed rhegmatogenous retinal detachment. Surgical treatment successfully restored or maintained retinal apposition in 74 (96.1%) of the eyes. Thirty-six (46.8%) eyes recovered visual acuity of 6/9 or better. Of the retinal breaks recognised dialysis at the ora serrata was observed in 49 eyes, of which 28 were situated at the lower temporal quadrant. Seventeen eyes had irregular breaks arising within necrotic retina at the site of scleral impact. Twenty-four (31.2%) patients had retinal break or retinal detachment diagnosed within 24 hours of injury and 49 (63.6%) within six weeks. Immediate retinal detachment was a feature of necrotic retinal breaks, while inferior oral dialyses led to a slow accumulation of subretinal fluid. Delayed diagnosis of retinal detachment was due either to opaque media or to failure to examine the retina after injury. Visual prognosis was good when retinal break or detachment were diagnosed within six weeks of injury. However, those patients who escaped initial retinal examination and were lost to follow-up had a less favourable visual outcome.

The effect of indomethacin 0.5% ophthalmic suspension in preventing surgically induced miosis during planned extracapsular cataract extraction

The effect of topical Indomethacin 0.5% ophthalmic suspension in preventing surgically induced miosis during planned extracapsular cataract extraction is examined. Eighteen patients received Indomethacin per-operatively while 16 did not and served as controls. Our study failed to show any difference in per-operative pupil size between either group.

Pseudophakic retinal detachments and post-operative visual acuity

We reviewed 254 cases of extracapsular cataract extraction and posterior chamber intraocular lenses (ECCE & IOL) which were performed between the years 1983 and 1985 at the Royal Victoria Hospital, Belfast. The aim of the study was to evaluate the incidence of pseudo-phakic retinal detachment in uncomplicated cases of ECCE & IOL. The incidence of retinal detachment (RD) was found to be 0.79% overall. The incidence of other post-operative complications such as posterior capsular thickening was 2.8% and of cystoid macular oedema 1.2%.