Noncontact transscleral Nd:YAG cyclophotocoagulation: a long-term follow-up of 500 patients.

Long-term experience with transscleral cyclophotocoagulation in 500 patients suggests that this operation is the cyclodestructive procedure of choice. It offers a reasonable surgical option in the high-risk glaucoma population, which includes patients with neovascular glaucoma, glaucomas with active uveitis, glaucomas in aphakia or pseudophakia, and other cases in which filtering surgery has failed or is felt to have a low chance for success. Satisfactory intraocular pressure reduction was achieved in 62% of the patients with one treatment session. After one or more repeated procedures in 21% of the study group, the final intraocular pressure was below baseline in 94%, with a mean final reduction of 24 mm Hg, which was judged to be adequate for 87% of the patients. However, visual loss remains a significant postoperative complication, with some degree of reduced vision occurring in 39% of the study population. Patients with neovascular glaucoma had the greatest percentage of visual loss at 46%, compared with 34% and 38% for patients with glaucomas in pseudophakia and aphakia, respectively. While it is hard to know how many of these cases of visual loss were a direct result of the cyclophotocoagulation, the procedure should be used with caution in eyes with a potential for good central vision. Further study is needed to determine the relative indications for transcleral cyclophotocoagulation and the various operations to increase aqueous outflow in the management of patients in the high-risk glaucoma population.

Major morbidity and mortality within 1 month of ambulatory surgery and anesthesia.

OBJECTIVE: To determine the incidence and time sequence of mortality and major morbidity after ambulatory surgery. DESIGN: Prospective outcome survey of patients at 16 to 72 hours and 30 days after their surgical procedures. SETTING: A tertiary care rural referral center providing ambulatory care. PATIENTS: A total of 38,598 patients aged 18 years and older undergoing 45,090 consecutive ambulatory procedures and anesthetics. Contact rates for 72 hours and 30 days were 99.94% and 95.9%, respectively. MAIN OUTCOME MEASURES: Mortality and major morbidity incidences, including myocardial infarction, central nervous system deficit, pulmonary embolism, and respiratory failure. RESULTS: Thirty-three patients either experienced major morbidity or died (1:1366 [proportional risk]). Four patients died (1:11,273), two of myocardial infarction and two in automobile accidents. No patient died of a medical complication within 1 week of surgery. Of the 31 patients who developed a major morbidity (1:1455), 14 (45%) had myocardial infarction (1:3220), seven (23%) had a central nervous system deficit (1:6441), five (16%) had pulmonary embolism (1:9018), and five (16%) had respiratory failure (1:9018). Four events (13%) occurred within 8 hours of surgery (1:11,273), 15 (48%) in the next 40 hours (1:3006), and 12 (39%) in the next 28 days (1:3758). CONCLUSION: In this ambulatory surgical population, more than one third of major morbidity occurred 48 hours or later after surgery. Overall morbidity and mortality rates, however, were very low.

Degradation of basement membrane collagens by metalloproteases released by human, murine and amphibian tumours.

In this investigation it has been found that naturally-occurring (i.e. indigenous, not transplanted) tumours of diverse organs in a spectrum of vertebrates from frogs to man can secrete enzymes which degrade basement membrane collagens (type IV and V). The enzymes are inhibited by chelating agents (EDTA) but not by other protease antagonists and are, therefore, specific metalloproteases. Individual tumours do not necessarily secrete collagenases active against all collagen types (I, IV and V) and release of these different enzymes does not, therefore, appear to be coordinated. These biochemical findings support those reported for serially transplanted tumour cell lines and provide a plausible mechanism for the destruction of basement membranes and stromal collagen fibres observed morphologically in tumour spread.

Density labelling characterisation of the effects of cordycepin and cycloheximide on the turnover of phenylalanine ammonia-lyase.

L-Phenylalanine ammonia-lyase (EC 4.3.1.5) undergoes a transient increase in activity in illuminated disc of Solanum tuberosum tuber parenchyme. Cycloheximide and cordycepin inhibit the initial increase in enzyme activity, but if addition of these anti-metabolites is delayed until the time of maximum enzyme levels, the subsequent decline in enzyme activity is inhibited (Lamb, C.J. (1977) Planta, 135, 169-175). The effect of delayed treatment with cycloheximide or cordycepin on the turnover of phenylalanine ammonia-lyase has been analysed by density labelling with 2H from 2H2O. Delayed introduction of cycloheximide or cordycepin reduces the rate of labelling of phenylalanine ammonia-lyase whilst preventing the decay in enzyme activity observed in controls not treated with inhibitor, and this labelling pattern cannot be accounted for by effects of cycloheximide or cordecypin on the labelling of amino acid pools. It is concluded that delayed treatment with cycloheximide or cordycepin leads to the maintenance of high levels of phenylalanine ammonia-lyase by inhibition of the removal of active enzyme rather than by maintenance of high rates of enzyme synthesis.