Injection of perfluoropropane gas to prevent hypotony in eyes undergoing tube implant surgery

Hypotony after fistulizing surgery is common, and most cases resolve without complications. Occasionally, a flat anterior chamber in phakic or pseudophakic eyes may lead to corneal decompensation or cataract formation. In aphakic eyes that have undergone previous vitreous surgery, flat anterior chambers will not develop, but large choroidal detachments and delayed suprachoroidal hemorrhage may occur while the eye is soft. To maintain intraocular pressure (IOP) in the early postoperative period, the authors used a technique to seal the drainage tube with a Vicryl tie, combined with injection of sodium hyaluronate, sulfur hexafluoride (SF6), or perfluoropropane (C3F8), perioperatively in 28 eyes undergoing glaucoma tube implant surgery. Eight eyes were treated with injection of sodium hyaluronate, 8 with SF6, and 12 eyes with C3F8. Hypotony was significantly less frequent in eyes treated with C3F8 compared with sodium hyaluronate (P less than 0.05). Mean IOP was significantly higher for eyes treated with C3F8 injection compared with sodium hyaluronate for the first 4 days after surgery (P less than 0.05).     

Long-term effects of glaucoma therapy with 4% pilocarpine gel on corneal clarity and endothelial cell density

Corneal thickness measurements and endothelial cell counts were carried out in 34 patients undergoing treatment for glaucoma with 4% pilocarpine gel between 18 to 78 months after initiation of therapy. The corneal thickness and endothelial cell population were found to be within normal limits in all cases except two, one patient with increased corneal thickness who had recently undergone cataract and glaucoma filtering surgery and another patient with decreased cell count who had an old endothelial scar sustained prior to pilocarpine gel therapy. There was a very close correlation for both of these parameters noticed in patients treated with pilocarpine gel and in age-matched control group of patients with glaucoma. The present study has shown that there are no adverse corneal effects with pilocarpine gel therapy.     

Retention of "safe" blood donors. The Retrovirus Epidemiology Donor Study

BACKGROUND: There are obvious advantages to increasing donor retention. However, for reasons of blood safety, certain donors may, in fact, be more desirable to retain than others. “Safe” donors are defined as those who provided a blood donation that was negative on all laboratory screening tests and who subsequently reported no behavioral risks in response to an anonymous survey. This study identifies the most important factors affecting the intention of “safe” donors to provide another donation. STUDY DESIGN AND METHODS: An anonymous survey asking about donation history, sexual history, injecting drug use, and recent donation experience was mailed to 50,162 randomly selected allogeneic donors (including directed donors) who gave blood from April through July or from October through December 1993 at one of the five United States blood centers participating in the Retrovirus Epidemiology Donor Study. Before mailing, questionnaires were coded to designate donors with nonreactive laboratory screening tests at their most recent donation. RESULTS: A total of 34,726 donors (69%) responded, with substantially higher response among repeat donors. According to reported intentions only, the vast majority of “safe” donors indicated a high likelihood of donating again within the next 12 months. Only 3.4 percent reported a low likelihood of donating again. A comparison of those likely to return and those unlikely to return reveals significant differences in demographics and in ratings of the donation experience. A higher proportion of those unlikely to return were first-time donors, minority-group donors, and donors with less education. The highest projected loss among “safe” donors was seen for those who gave a fair to poor assessment of their treatment by blood center staff or of their physical well-being during or after donating. CONCLUSION: These data suggest that efforts to improve donors' perceptions of their donation experience, as well as attention to the physical effects of blood donation, may aid in the retention of both repeat and first-time donors.     

Biochemical approach to new medications.

In this plenary symposium address, the author describes historically his progress from the antimetabolite 2,6-diaminopurine to 6-mercaptopurine as a useful drug against tumours and leukaemia. Subsequently a 6-mercaptopurine derivative, and eventually azathioprine, were discovered to be useful drugs to ensure kidney transplant acceptance. Several of his group's diaminopurines proved to be selective antifolates in combatting pathogenic bacteria when combined with sulfanilamide, a useful drug combination already estimated to have saved a million lives.     

Surgery for normal tension glaucoma.

The long term follow up of surgery in normal tension glaucoma is presented. One eye of 18 patients with bilateral progressive disease underwent fistulising surgery. Over follow up periods ranging from 2 to 7 years (50% > or = 5 years) the operated eye showed on average a 30% reduction in intraocular pressure (IOP). This was associated with a marked difference in the rate and number of retinal locations showing a progressive decline in retinal function, suggesting some protective function for lowering IOP in patients with normal tension glaucoma.     

Frequent ongoing T-cell receptor rearrangements in childhood B- precursor acute lymphoblastic leukemia: implications for monitoring minimal residual disease

Crosslineage T-cell receptor delta (TCR delta) rearrangements are widely used as tumor markers for the follow up of minimal residual disease in childhood B-precursor acute lymphoblastic leukemia (ALL) by polymerase chain reaction (PCR). The major drawback of this approach is the risk of false-negative results due to clonal evolution. We investigated the stability of V delta 2D delta 3 rearrangements in a group of 56 childhood B-precursor ALL patients by PCR and Southern blot analysis. At the PCR level, V delta 2D delta 3-to-J alpha rearranged subclones (one pathway for secondary TCR delta recombination) were demonstrated in 85.2% of V delta 2D delta 3-positive patients tested, which showed that small subclones are present in the large majority of patients despite apparently monoclonal TCR delta Southern blot patterns. Sequence analysis of V delta 2D delta 3J alpha rearrangements showed a biased J alpha gene usage, with HAPO5 and J alpha F in 26 of 32 and 6 of 32 clones, respectively. Comparison of V delta 2D delta 3 rearrangement status between diagnosis and first relapse showed differences in seven of eight patients studied. In contrast, from first relapse onward, no clonal changes were observed in six patients studied. To investigate the occurrence of crosslineage TCR delta rearrangements in normal B and T cells, fluorescence-activated cell sorter-sorted peripheral blood CD19+/CD3- and CD19-/CD3+ cell populations from three healthy donors were analyzed. V delta 2D delta 3 rearrangements were detected at low frequencies in both B and T cells, which suggests that V delta 2-to-D delta 3 joining also occurs during normal B-cell differentiation. A model for crosslineage TCR delta rearrangements in B-precursor ALL is deduced that explains the observed clonal changes between diagnosis and relapse and is compatible with multistep leukemogenesis of B-precursor ALL.