Analysis of liquid accumulated in the distended capsular bag in early postoperative capsular block syndrome

PURPOSE

To analyze the transparent liquid between the posterior lens capsule and the posterior chamber intraocular lens (PC IOL) in early postoperative capsular block syndrome and discuss the mechanism of posterior capsule distention.

SETTING

Department of Ophthalmology, Tokyo University School of Medicine, and Tokyo Research Institute, Seikagaku Corporation, Tokyo, Japan.

METHODS

This study evaluated 3 cases of capsular block syndrome presenting with transparent liquid in the distended capsular bag 1 day after cataract surgery. The transparent liquid material between the posterior capsule and PC IOL was aspirated and analyzed using high-performance liquid chromatography (HPLC). Also, sodium hyaluronate was diluted using a dialyzer to determine whether the aqueous humor was drawn into the capsular bag by an osmotic gradient across the capsule.

RESULTS

The elution time of the samples was almost the same as that of sodium hyaluronate 1.0% (Healon) The concentration of the samples ranged from 3.29 to 9. 01 mg/mL by HPLC analysis. The sodium hyaluronate absorbed the physiological salt solutions through the dialyzer and expanded to 1. 9 times its original volume.

CONCLUSIONS

These results indicate that the main ingredient of the transparent liquid in capsular bags is sodium hyaluronate and that the distention is caused by aqueous humor being drawn into the capsular bag by an osmotic gradient across the capsule when the capsulorhexis diameter is smaller than that of the PC IOL and by viscoelastic material retained and trapped in the bag intraoperatively.

Role of the cytomegalovirus (CMV)-antigenemia assay as a predictive and follow-up detection tool for CMV disease in AIDS patients

Forty-two patients were evaluated to determine the value of the CMV antigenemia (CMV-Ag) test as a follow-up marker as well as a prediction marker of CMV disease. Twenty patients were positive for at least one positive CMV-Ag assay and 9 of them developed CMV retinitis. With the threshold value (10 positive cells), sensitivity was 56% and specificity was 94%. The CMV-Ag assay, with the threshold value, produced high specificity, positive predictive value and negative predictive value but relatively poor sensitivity. Eight patients experienced CMV disease relapse a total of 16 times. At relapse, 8 of the 16 times showed negative for CMV-Ag assay; 7 underwent systemic maintenance while 1 underwent local maintenance. It is inferred that the CMV-Ag test is a poor follow-up marker to detect the relapse of CMV disease, particularly in patients undergoing systemic maintenance.

Optimal level of pressure support ventilation for recovery from diaphragmatic fatigue in rabbits

OBJECTIVE

To determine whether there is an optimal level of pressure support ventilation (PSV) for recovery from acute diaphragmatic fatigue.

DESIGN

Prospective laboratory trial.

SETTING

Experimental laboratory.

SUBJECTS

Twenty healthy adult New Zealand White rabbits.

INTERVENTIONS

Diaphragmatic fatigue was induced with 50 Hz of phrenic nerve stimulation for 30 mins. Recovery was compared between inspiratory load + PSV of 0 cm H2O (L0), inspiratory load + PSV of 60 cm H2O (L60), inspiratory load + PSV of 80 cm H2O (L80), and PSV of 0 cm H2O without inspiratory load (SB) for 90 mins immediately after the end of the fatigue-inducing procedure. To add inspiratory load during the recovery phase, three pressure threshold valves, each having an opening pressure of -20 cm H2O, were used.

MEASUREMENTS AND MAIN RESULTS

After the fatigue-inducing procedure, diaphragmatic electromyogram and transdiaphragmatic pressure remained at baseline in both SB and L60, decreased in L80, and increased in L0. Recovery was assessed by abdominal cavity pressure (Pabd) generated by high-frequency (100 Hz) and low-frequency (20 Hz) stimulation. Pabd at 100 Hz recovered to baseline in L60 and SB but not in L0 and L80 (69.1%, 81.3%, 100.3%, and 100.7% of the baseline at 90 mins for L0, L80, L60, and SB, respectively). Pabd at 20 Hz did not differ among ventilatory settings.

CONCLUSION

There is an optimal range of PSV assist level to improve recovery from diaphragmatic fatigue. Recovery was hampered not only by inadequate PSV but also by excessive PSV.

Surface active properties of simple cyclic and heterocyclic amines in water

The surface tension of aqueous solutions of simple cyclic, heterocyclic and aromatic amines was measured with a Du Nöuy tensiometer at 25 degrees C and the results discussed in terms of structure-aggregation relationships. The simple compounds used in this study were piperazine, piperidine, morpholine, 3-methylpyridine, cyclohexylamine and benzylamine, with carbon numbers ranging from four to seven. Piperazine, piperidine and morpholine did not form micellar associations but cyclohexylamine, benzylamine and 3-methylpyridine did, indicating that more than six carbons are necessary to form micellar associations, at least for compounds having a six-membered ring.

The relationship between gas delivery patterns and the lower inflection point of the pressure-volume curve during partial liquid ventilation

STUDY QUESTION

To determine whether a positive end-expiratory pressure (PEEP) level equivalent to the lower inflection point (LIP) could be identified by evaluation of the airway pressure, flow (f1. gif" BORDER="0">), and volume vs time waveforms during partial liquid ventilation (PLV).

DESIGN

Prospective application of PEEP during PLV in a healthy animal model.

SETTING

University hospital animal laboratory.

PARTICIPANTS

Five healthy sheep weighing 30 kg each.

INTERVENTIONS

The sequential application of 0 to 20 cm H(2)O PEEP in 2.5-cm H(2)O steps during PLV with both pressure and volume ventilation.

MEASUREMENTS

Analysis of the pressure, volume, and f1. gif" BORDER="0"> waveforms as PEEP is sequentially increased.

RESULTS

At 0 cm H(2)O PEEP, VT was markedly reduced compared with PEEP VT at > or = 7.5 cm H(2)O (p < 0.05) in pressure control ventilation (PCV), and peak inspiratory pressure minus PEEP was markedly increased compared with PEEP at > or = 5.0 cm H(2)O (p < 0.05) in volume control ventilation. At 10 cm H(2)O PEEP, all waveforms began to stabilize, and no significant differences in any variable assessed were measured at > 12.5 cm H(2)O PEEP.

CONCLUSIONS

The application of PEEP during PLV markedly alters airway waveforms. Low PEEP decreases VT in PCV and increases airway pressure in VCV. The PEEP level equal to the LIP during PLV can be grossly estimated from airway waveforms. PEEP at > or = 10 cm H(2)O is needed to normalize gas delivery to functional residual capacity in the uninjured lung that is partially filled with perfluorocarbon.

[Evaluation of mortality of patients admitted to ICU for the last 12 years]

We evaluated mortality of 2689 patients admitted to the Intensive Care Unit, Osaka University Hospital from January, 1987 to December, 1998. The patients were divided into 3 groups. Group A consisted of 1408 patients who underwent cardiovascular surgery, group B, 1082 patients who underwent other surgical procedures and group C, 199 patients who were transferred from the department of medicine. We studied mortality rate, causes of death, correlation between length of ICU stay and mortality rate, and mortality rate among age groups for 12 years. The main causes of death were cardiac failure and sepsis in group A, and respiratory failure and sepsis in group B and C. Mortality rate in each group showed no significant change for the last 12 years. Those who stayed more than 2 weeks in ICU showed a significantly higher mortality rate (p < 0.0001). Thus, length of ICU stay and mortality rate showed a positive correlation (p < 0.0001). The youngest group (age 0-1) showed a significantly higher mortality rate than other age groups (p < 0.0001). As sepsis was the most important cause of death in all the groups, the prevention and treatment of infection are the most important issue in our ICU to reduce mortality rate.

Pressure-release tracheal gas insufflation reduces airway pressures in lung-injured sheep maintaining eucapnia

Although tracheal gas insufflation (TGI) has proved to be a useful adjunct to mechanical ventilation, end-inspiratory as well as end-expiratory pressures may increase. We investigated the ability of continuous-flow TGI to maintain eucapnia while reducing airway pressure (Paw) and tidal volume (VT). Seven sheep (36 +/- 2 kg) were ventilated using the Dräger Evita 4 in the pressure control plus mode where flow is released via the expiratory valve to maintain constant inspiratory pressure. To avoid TGI-generated positive end-expiratory pressure (PEEP), a prototype reverse flow TGI tube was used. Two TGI flows (5 and 10 L/min) were investigated pre- and postsaline lavage-induced lung injury. Inspiratory pressures and VT were significantly reduced as TGI flow increased. At 10 L/min TGI flow the carinal pressures (Pcar) and VT were reduced pre- and postinjury by 15% and 20%, and by 28% and 34%, respectively. Tidal volume to dead space ratio (VD/VT) decreased preinjury from 0.49 +/- 0.1 to 0.18 +/- 0.2 and postinjury from 0.62 +/- 0.1 to 0.33 +/- 0.1 at a TGI flow of 10 L/min. The combination of the reverse flow TGI tube and a ventilator with an inspiratory pressure relief mechanism kept set end-inspiratory and end-expiratory pressures constant. This TGI system effectively reduced set Paw and VT while maintaining eucapnia.

[Neurological complications of ulcerative colitis]

Extraintestinal complications of ulcerative colitis(UC) affect various organ systems. However, there is a notable sparing of the nervous system. In this review, we describe the complications of nervous system dividing into some categories. Most frequently reported is cerebrovascular disease(CVD), which occurs in hypercoagulable state or vasculitis. Young patient with active UC seems to be a risk of CVD. Some authors suggest that the familial concurrence of multiple sclerosis and UC. However, there is only one report in Japan. Myopathy and neuropathy are rare diseases in a group of this review. The former are considered an overlapping occurrence of UC. The latter have various areas in peripheral nervous system. A detailed investigation of immunological back-ground is required to define the nature of their association.

Effects of monoclonal antibodies directed at cell surface molecules on murine experimental autoimmune uveoretinitis

BACKGROUND

To elucidate the immunopathogenic mechanism of endogenous uveitis, the effects of monoclonal antibodies to molecules involved in the immune response were studied in murine experimental autoimmune uveoretinitis (EAU).

METHODS

Monoclonal antibodies to CD4, CD8, Ia(k), Ia(d), lymphocyte function-associated antigen-1 (LFA-1), and intercellular adhesion molecule-1 (ICAM-1) were used in this study. The monoclonal antibodies were added in the culture of lymph node cells from B10.BR mice(H-2(K)) immunized with interphotoreceptor retinoid-binding protein (IRBP) and the inhibition of proliferative response was measured. In vivo, IRBP-immunized mice were treated with a high dose of the antibody, and the EAU induction was examined both clinically and pathologically.

RESULTS

Proliferative response of IRBP-sensitized lymph node cells was inhibited strongly by anti-CD4 or anti-LFA-1 monoclonal antibody and moderately by anti-Ia(k) or anti-ICAM-1 monoclonal antibody. In contrast, no inhibitory effect of anti-CD8 or anti-Ia(d) monoclonal antibody was observed. In vivo treatment with anti-CD4 monoclonal antibody inhibited development of EAU in a dose-dependent manner, while in vivo treatment with other monoclonal antibodies did not cause significant suppression of EAU.

CONCLUSIONS

CD4, Ia, LFA-1, and ICAM-1 molecules play important roles in the antigen-specific immune response of lymphocytes. However, in in vivo treatment with monoclonal antibodies to these molecules, only anti-CD4 monoclonal antibody had a strong inhibitory effect on the development of EAU.

Possible functions of oxytocin/vasopressin-superfamily peptides in annelids with special reference to reproduction and osmoregulation

Annetocin is an earthworm oxytocin-related peptide that we previously isolated from the whole body of a lumbricid earthworm Eisenia foetida. We have reported that annetocin induces egg-laying-like behaviors in E. foetida and a gnathobdellid leech, Whitmania pigra, when it is injected into the respective animals. The present study was undertaken to probe physiological functions of invertebrate oxytocin-vasopressin-superfamily peptides with special reference to reproductive and osmoregulatory events in which vertebrate peptides of this superfamily are involved. Annetocin, Lys-conopressin (a leech vasopressin-related peptide) and two analog peptides, [Tyr(3)]-annetocin ((3)Y-annetocin) and [Phe(3)]-annetocin ((3)F-annetocin), were compared for their activities to induce egg-laying-like behavior and to change body weight as a measure of water balance in the leech W. pigra. Injection of annetocin, Lys-conopressin, and (3)F-annetocin caused both egg-laying-like behavior and reduction of body weight in the animals, but (3)Y-annetocin induced neither. Furthermore, leeches in the non-breeding season responded to peptides less conspicuously than those in the breeding season. Such a concomitant induction of egg-laying-like behavior and body-weight reduction suggests that these two phenomena are unitary and might be accounted for by the fact that egg-laying in leeches and earthworms is accompanied by secretion of a large quantity of mucus, which should significantly contribute to body-weight loss. J. Exp. Zool. 284:401-406, 1999.

Experimental uveitis induced by intravitreal or intravenous lipoteichoic acid in rabbits

PURPOSE

To investigate the role of lipoteichoic acid (LTA), one of the cell wall components in gram-positive bacteria in uveitis.

METHODS

Intraocular inflammation in rabbit eyes was induced by intravitreal or intravenous injections of LTA from Staphylococcus aureus or Streptococcus sanguis. The inflammation was monitored progressively with the laser flare-cell photometer, and examined by periodic clinical observations. Histological examinations were performed 24 hours after administration, and aqueous protein concentrations and cell counts were also determined.

RESULTS

Intraocular inflammation appeared within 6-9 hours of LTA intravitreal injection. became maximal at about 24-48 hours postinjection, and lasted for nearly 6 days. Intraocular inflammation was also induced by intravenous injection of LTA at a higher dose. Inflammation reached a peak 4-5 hours after injection, and rapidly disappeared in 24 hours. No cellular response was observed in intravenous LTA-treated eyes.

CONCLUSIONS

This study demonstrates that LTAs from gram-positive bacteria have the biological activity to induce intraocular inflammation in rabbits by intravitreal or intravenous injection. Therefore, we suggest that LTA may play a role in the pathogenesis of uveitis as one of the etiological factors.

[Two cases of frosted retinal angiitis with central retinal vein occlusion]

BACKGROUND

Frosted retinal angiitis usually occurs in children, and has a good prognosis. We report two cases of unilateral frosted retinal angiitis in adults. They resulted in visual degradation because of associated central retinal vein occlusion and neovascular glaucoma.

CASES

Case 1 was a 36-year-old female. Almost all retinal veins and some retinal arteries had vasculitis in her right eye, and the veins were slightly dilated and sheathed. Case 2 was a 23-year-old female. Angle hypopyon was observed in her left eye. Retinal veins were dilated, meandered, and sheathed. Retinal hemorrhages were also observed. In both cases, systemic steroid therapy gradually improved the retinal vasculitis, but central retinal vein occlusions gradually developed, and in spite of systemic administration of urokinase and panretinal photocoagulation, neovascular glaucoma developed, and visual acuity became degraded in both cases.

CONCLUSION

Two cases of frosted retinal angiitis complicated by retinal vein occlusion were reported. Careful observation of retinal blood flow is necessary in frosted retinal angiitis in adults.

Ciclosporin microemulsion preconcentrate treatment of patients with Behçet's disease

PURPOSE

The new microemulsion preconcentrate (MEPC) formulation of ciclosporin has been developed to reduce problems in intestinal absorption and to stabilize fluctuations in blood levels. A multicenter, open-label clinical trial of MEPC was conducted to assess its efficacy and safety in Behçet's disease patients with ocular involvement.

METHODS

The patient population comprised 17 de novo patients (patients not previously treated with ciclosporin in the currently available formulation) and 30 patients whose ciclosporin formulation was switched from the conventional formulation to MEPC. The patients were treated with the test formulation for 16 weeks in the former (de novo) group and for 12 weeks in the latter (switched) group.

RESULTS

In the de novo group, ocular attacks decreased significantly as compared to the pretreatment incidence in 11 of the 14 patients (78.6%) evaluated after MEPC therapy. Ocular attacks also decreased significantly in the switched group. In the de novo group, visual acuity improved with MEPC therapy in 20 of the 28 eyes (71.4%) examined, and the overall efficacy evaluation was "improved" or "markedly improved" in 13 of the 16 patients evaluated (81.3%). The one case each of onset of neuro-Behçet's disease and intestinal Behçet's disease observed in the de novo group were regarded as adverse reactions.

CONCLUSION

It was concluded that ciclosporin MEPC is useful for controlling the ocular symptoms of Behçet's disease, and that it can be used as effectively and safely as the conventional formulation.

Epidemiological features and visual prognosis of Behçet's disease

PURPOSE

Retrospective evaluation of epidemiological features and visual prognosis of patients with Behçet's disease (BD) who visited the University of Tokyo Hospital between 1974 and 1993.

OBSERVATIONS

During the survey period, more than 100 new patients with BD visited the uveitis clinic in each 5-year period. The number of new patients decreased in the most recent 5-year period from 1989 to 1993. Although BD has always been more prevalent in men, the percentage of women has increased to 24.7% (19/77) in the most recent 5-year survey period. The percentage of patients who initially manifested ocular symptoms in their third or fourth decade was more than 70%. The proportion of the incomplete type of BD gradually had increased to 62.3% (48/77) by 1993. Among the extraocular major symptoms, oral aphtha and skin lesions have been frequent and genital ulcer has become less frequent in the last 20 years. The patients whose visual acuity was better than 0.4 at the first visit in the 1984-1993 period had a significantly better visual prognosis than the patients in the previous 10-year period. The main drug therapy consisted of colchicine and cyclophosphamide in the earlier 10-year period, and of colchicine and ciclosporin in the later 10-year period.

CONCLUSIONS

Behçet's disease is still one of the most frequently encountered types of endogenous uveitis. There have been some changes in the epidemiological features of the patients with BD over the past 20 years. The introduction of ciclosporin in 1985 is probably responsible for the improvement of the visual prognosis in BD patients.

Evaluation of endoscopic ultrasonography as an indicator for surgical treatment of gastric cancer

BACKGROUND AND METHODS

Clinicopathological analysis of 346 patients with gastric cancer was made retrospectively and new criteria for the indication of a limited operation using endoscopic ultrasonography (EUS) was developed. Suggested new criteria for selecting gastric cancer patients for the limited operation were: (i) the cancer is located in the mucosa and the lymph nodes are not involved as indicated by EUS examination; (ii) the maximum size of the tumour is less than 2.0 cm; (iii) there are no multiple gastric cancers or simultaneous abdominal cancers; and (iv) the mucosal cancer of elevated type less than 2.0 cm is excluded because there are good indications for endoscopic mucosal resection.

RESULTS AND CONCLUSIONS

We applied these new criteria to 262 patients and found that the patients who had limited operation had the same prognosis and a better quality of life compared with patients who had the conventional operation.

Unilateral papilledema after bone marrow transplantation

We describe a patient who developed unilateral papilledema after allogeneic BMT. This is a rare manifestation of pseudotumor cerebri, which results from elevated intracranial pressure caused by cyclosporin A. The papilledema usually involves the fundi bilaterally, but unilateral involvement has been described. Congenital anomalies, compression and adhesion of the optic nerve sheath are its causes. In this patient, the right optic fundus was spared although leukemic infiltration was present on this side and high-dose irradiation (72 Gy) was given. Although papilledema is a sensitive marker of elevated intracranial pressure, this sign may be masked by constriction of the optic sheath in patients who suffer from leukemic infiltration of the central nervous system and receive high doses of cranial irradiation.

Randomized clinical trial of ultrasonic dissector or conventional division in distal pancreatectomy for non-fibrotic pancreas

BACKGROUND

Resection of the non-fibrotic pancreas is prone to postoperative pancreatic fistula because of well preserved exocrine secretions and easily crushed soft parenchyma. The purpose of this study was to evaluate ultrasonic dissection for division of the non-fibrotic pancreas in distal pancreatectomy.

METHODS

All pancreata included in this study were soft on direct palpation and their main ducts had no dilatation, at least proximally from the transection line. Fifty-eight patients with gastric cancer or pancreatic disease were randomly assigned to the two groups. In the ultrasonic dissection (UD) group (n = 27), all pancreatic ducts were identified and ligated securely. The stump was left open without parenchymal suturing. In the conventional (CV) group (n = 31), the pancreas was cut with a knife and the stump was oversewn in mattress fashion. The main pancreatic duct was ligated in all patients in both groups. Pancreatic fistula was defined as a pancreatic fluid discharge for more than 7 days after operation diagnosed according to amylase concentration in the drainage fluid.

RESULTS

In the UD group, approximately 20-30 tubes including a mean(s.d.) 5.2(0.8) (range 4-6) pancreatic ducts were skeletonized and ligated per patient. There were nine pancreatic fistulas (16 per cent); one in the UD group and eight in the CV group (P = 0.020).

CONCLUSION

In distal pancreatectomy for the non-fibrotic pancreas, ultrasonic dissection without suture closure of the stump reduced the incidence of pancreatic fistula compared with conventional division and suture, in this randomized trial.

The effect of mode, inspiratory time, and positive end-expiratory pressure on partial liquid ventilation

Partial liquid ventilation (PLV) has been shown to be an effective means of improving oxygenation in the injured lung. However, little is known about how approach to ventilation during PLV affects gas exchange and pulmonary mechanics. We hypothesized that gas exchange and pulmonary mechanics would be best with positive end-expiratory pressure (PEEP) set above the lower inflection point (LIP) of the pressure-volume (P-V) curve regardless of mode of ventilation or inspiratory to expiratory time (I:E) ratio and that the efficiency of ventilation would be greatest with volume-controlled ventilation (VCV) compared with pressure-controlled ventilation (PCV) and with long inspiratory time as compared with short inspiratory time. Lung injury was induced in 14 sheep by lavage, 10 of which were studied. Sheep were then assigned to high-PEEP (Group H, n = 5) and low-PEEP (Group L, n = 5) groups. In Group H applied PEEP was set at the LIP and in Group L applied PEEP was set at 5 cm H2O after the lung was filled with perflubron (PFB). We randomly compared VCV and PCV with I:E ratios of 1:2, 1:1, and 2:1. Peak inspiratory pressure and VT were adjusted to maintain a constant end-inspiratory plateau pressure (Pplat) of about 25 cm H2O in both groups and a constant total PEEP of about 5 cm H2O in Group L and about 12 cm H2O in Group H. There were no differences in oxygenation among modes in Group H. In Group L VCV 2:1 and all of the PCV modes in Group L had a lower PaO2 than VCV 1:1 (p < 0.05). PaCO2 and VD/VT were significantly different (p < 0.05) among modes. VD/VT was highest during PCV 1:2 with PEEP of 5 cm H2O (p < 0.05). Quasi-static compliance in Group H was higher than in Group L (p < 0.05). We conclude that during low PEEP gas exchange deteriorated in VCV with long inspiratory time and in PCV. Oxygenation was enhanced during VCV 1:1 when compared with VCV at longer I:E ratios or PCV at any I:E ratio. With PEEP set at the LIP, adequate gas exchange and improved lung mechanics could be obtained in all modes assessed.

Dynamic measurement of intrinsic PEEP does not represent the lowest intrinsic PEEP

OBJECTIVE

Dynamic intrinsic PEEP (PEEPi-dyn) is the airway pressure required to overcome expiratory flow and is considered to represent the lowest regional PEEPi. However, there are few data to validate this assumption. We investigated if PEEPi-dyn represents the lowest PEEPi.

SETTING

The animal laboratory at the Osaka University Medical School.

MEASUREMENTS AND RESULTS

We compared static PEEPi (PEEPi-stat) and PEEPi-dyn in healthy animals. Five adult white rabbits (2.77+/-0.05 kg) were anesthetized, tracheostomized, and intubated with several different sizes of endotracheal tubes (ETT) (2.0, 2.5, 3.0, 3.5, or 4.0 mm i.d.). The animals were paralyzed and ventilated (Siemens Servo 900C). Baseline ventilator settings were at a rate of 50/min, inspiratory:expiratory (I:E) ratio of 2:1 or 4:1, and minute ventilation was manipulated to create 3 or 5 cm H2O PEEPi-stat. PEEPi-stat was measured using the expiratory hold button of the ventilator. PEEPi-dyn showed large variations. In all ventilator settings, PEEPi-dyn was higher than PEEPi-stat (p<0.001). The larger the ETT, the higher the PEEPi-dyn at an I:E ratio of 2:1 (p<0.05). The higher the minute ventilation, the greater the difference between PEEPi-stat and PEEPi-dyn. The tidal volume and the difference showed a significant correlation (r2 = 0.514, p<0.001).

CONCLUSIONS

The value of PEEPi-dyn was dependent on ventilatory settings, and PEEPi-dyn does not necessarily represent the lowest regional PEEPi within the lungs.

[Cataract surgery and intraocular lens implantation in patients with Behçet's disease]

PURPOSE

To evaluate the outcome of cataract surgery in patients with Behçet's disease.

METHODS

The results of 27 eyes of 19 patients with Behçet's disease that had undergone cataract surgery with or without intraocular lens implantation from October 1993 to December 1996 were retrospectively analyzed. The postoperative follow-up period ranged from 13 to 50 months (average, 28 months).

FINDINGS

Visual acuity improved postoperatively in 25 eyes, to 20/40 or better in 9 eyes. In 19 eyes, ocular attacks were seen within the preoperative 6 months in 2 eyes, and within the postoperative 6 months in 8 eyes. In 8 eyes, the first ocular attacks occurred within 2 months after the surgery. The frequency of ocular attacks increased after the surgery in 7 patients who received immunosuppressive a gents, with relatively short duration of the disease.

CONCLUSION

These results suggest that the frequency of ocular attacks increases after cataract surgery in some patients who use immunosuppressive agents for controlling ocular attacks, even though they had no inflammatory history for a long period before the surgery.

Positive end-expiratory pressure improves gas exchange and pulmonary mechanics during partial liquid ventilation

Partial liquid ventilation (PLV) with perflubron (PFB) has been proposed as an adjunct to the current therapies for the acute respiratory distress syndrome (ARDS). Because PFB has been also referred to as "liquid PEEP," distributing to the most gravity-dependent regions of the lung, less attention has been paid to the amount of applied positive end-expiratory pressure (PEEP). We hypothesized that higher PEEP levels than currently applied are needed to optimize gas exchange, and that the lower inflection point (LIP) of the pressure-volume curve could be used to estimate the amount of PEEP needed when the lung is filled with PFB. Lung injury was induced in 23 sheep by repeated lung lavage with warmed saline until the PaO2/FIO2 ratio fell below 150. Five sheep were used to investigate the change of the LIP when the lung was filled with PFB in increments of 5 ml/kg/body weight to a total of 30 ml/kg/body weight. To evaluate the impact of PEEP set at LIP +1 cm H2O we randomized an additional 15 sheep to three groups with different doses (7.5 ml, 15 ml, 30 ml/kg/body weight) of PFB. In random order a PEEP of 5 cm H2O or PEEP at LIP +1 cm H2O was applied. The LIP decreased with incremental filling of PFB to a minimum at 10 ml (p < 0.05). Increasing PEEP from below LIP to LIP +1 cm H2O at 15 and 30 ml/kg resulted in an improvement in PaO2 from 152 +/- 36 to 203 +/- 68 (NS) and 193 +/- 57 to 298 +/- 80 (p < 0.05), respectively. Pulmonary shunt, and ratio of dead space volume to tidal volume (VD/VT) decreased, and static lung compliance increased with PEEP at LIP +1 cm H2O (p < 0.05). No changes were observed in hemodynamics. We conclude that increasing the dose of PFB shifts the LIP to the left, and that setting PEEP at LIP +1 cm H2O improves gas exchange at moderate to high doses of PFB.