Cysteine 230 is essential for the structure and activity of the cytotoxic ligand TRAIL

Unlike other tumor necrosis factor family members, the cytotoxic ligand tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)/Apo-2L contains an unpaired cysteine residue (Cys(230)) in its receptor-binding domain. Here we show that the biological activity of both soluble recombinant TRAIL and cell-associated, full-length TRAIL is critically dependent on the presence of Cys(230). Mutation of Cys(230) to alanine or serine strongly affected its ability to kill target cells. Binding to its receptors was decreased by at least 200-fold, and the stability of its trimeric structure was reduced. In recombinant TRAIL, Cys(230) was found engaged either in interchain disulfide bridge formation, resulting in poorly active TRAIL, or in the chelation of one zinc atom per TRAIL trimer in the active, pro-apoptotic form of TRAIL.

alpha-t-butyl- and alpha-i-propyl-ortho-hydroxybenzylamines: racemic synthesis/resolution and asymmetric synthesis

Efficient routes to alpha-tert-butyl- and alpha-iso-propyl-ortho-hydroxybenzylamines 1a and 1b are described. Highly enantioenriched 1a and 1b were obtained by resolution of the methoxy derivatives 2 by recrystallization of the salts formed with mandelic acid followed by Lewis acid mediated demethylation. The chiral 1,3-amino alcohol 1a has also been obtained in an asymmetric synthesis with the key step a diastereoselective alkylation of the imine obtained by condensation of o-anisaldehyde with phenyl glycinol. The absolute stereochemistry of these 1,3-aminophenols was determined by CD spectroscopy of the salicylideneamines 12 and by an X-ray structure analysis of the salt formed between (R)-mandelic acid and (S)-alpha-tert-butyl-ortho-methoxybenzylamine ((S)-2a).

Direct MR arthrography of the shoulder: is exercise prior to imaging beneficial or detrimental?

PURPOSE

To define the beneficial and detrimental effects of adding exercise to direct magnetic resonance (MR) shoulder arthrography.

MATERIALS AND METHODS

Direct, intraarticular, gadolinium arthrography of the shoulder was performed in 41 patients, who underwent 1.5-T MR imaging before and after 1 minute of arm swinging. Fourteen milliliters of dilute gadolinium solution was injected. Two readers blinded to exercise independently graded the randomly distributed images with a five-point scale for capsular contrast material resorption; extraarticular contrast material leakage; rotator cuff, glenoid labrum, and anterior capsule conspicuity; and partial-thickness or full-thickness rotator cuff tear and labral tear detectability. The sign test was performed to evaluate the significance of differences between preexercise and postexercise grading for each reader. A second review was performed, with direct side-by-side comparison of preexercise and postexercise images.

RESULTS

There was evidence of increased capsular resorption after exercise but no alteration in the depiction of the rotator cuff tendons or glenoid labrum. There was no significant extraarticular contrast material leakage after exercise and no alteration in depiction of the anterior capsule. There was no difference in the detectability of rotator cuff or labral tears.

CONCLUSION

Exercise with direct shoulder MR arthrography has no beneficial or detrimental effect on image quality or on the depiction of rotator cuff or labral tears.

Nitric oxide modulates expression of cell cycle regulatory proteins: a cytostatic strategy for inhibition of human vascular smooth muscle cell proliferation

BACKGROUND

We examined the effect of NO on the proliferation and cell cycle regulation of human aortic vascular smooth muscle cells (VSMCs).

METHODS AND RESULTS

The NO donor diethylenetriamineNONOate (10(-5) to 10(-3) mol/L) inhibited proliferation in response to 10% fetal calf serum (FCS) and 100 ng/mL platelet-derived growth factor-BB in a concentration-dependent manner. This effect was not observed with disintegrated diethylenetriamineNONOate or with the parent compound, diethylenetriamine. Adenoviral transfection of endothelial NO synthase (NOS) inhibited proliferation in response to FCS, which was prevented with N(G)-nitro-L-arginine methyl ester. NOS overexpression did not inhibit proliferation in response to platelet-derived growth factor, although the transfection efficiency and protein expression were similar to those of FCS-stimulated cells. Nitrate release was selectively enhanced from FCS-treated cells, indicating that NOS was activated by FCS only. NO caused G(1) cell cycle arrest. Cytotoxicity was determined with trypan blue exclusion, and apoptosis was assessed with DNA fragmentation. Cyclin-dependent kinase 2 expression level, threonine phosphorylation, and kinase activity were inhibited. Cyclin A expression was blunted, whereas cyclin E remained unchanged. p21 expression was induced, and p27 remained unaltered. The effect on cyclin A and p21 started within 6 hours and preceded the changes in cell cycle distribution. Proliferation in response to 10% FCS was barely inhibited with 8-bromo-cGMP (10(-3) mol/L) but was blunted with both forskolin and 8-bromo-cAMP. Proliferation in response to 2% FCS was inhibited with 8-bromo-cGMP, but it did not mimic the cell cycle effects of NO.

CONCLUSIONS

NO inhibits VSMC proliferation by specifically changing the expression and activity of cell cycle regulatory proteins, which may occur independent of cGMP. Adenoviral overexpression of endothelial NOS represents a cytostatic strategy for gene therapy of vascular disease.

The Drosophila caspase DRONC is regulated by DIAP1

We have isolated the recently identified Drosophila caspase DRONC through its interaction with the effector caspase drICE. Ectopic expression of DRONC induces cell death in Schizosaccharomyces pombe, mammalian fibroblasts and the developing Drosophila eye. The caspase inhibitor p35 fails to rescue DRONC-induced cell death in vivo and is not cleaved by DRONC in vitro, making DRONC the first identified p35-resistant caspase. The DRONC pro-domain interacts with Drosphila inhibitor of apoptosis protein 1 (DIAP1), and co-expression of DIAP1 in the developing Drosophila eye completely reverts the eye ablation phenotype induced by pro-DRONC expression. In contrast, DIAP1 fails to rescue eye ablation induced by DRONC lacking the pro-domain, indicating that interaction of DIAP1 with the pro-domain of DRONC is required for suppression of DRONC-mediated cell death. Heterozygosity at the diap1 locus enhances the pro-DRONC eye phenotype, consistent with a role for endogenous DIAP1 in suppression of DRONC activation. Both heterozygosity at the dronc locus and expression of dominant-negative DRONC mutants suppress the eye phenotype caused by reaper (RPR) and head involution defective (HID), consistent with the idea that DRONC functions in the RPR and HID pathway.

Massive suprachoroidal hemorrhage: secondary treatment and outcome

PURPOSE

Massive suprachoroidal expulsive hemorrhage (SCH) is a dramatic and devastating intraocular complication of intraocular surgery and trauma that can result in total loss of vision. The aim of our study was to present the results of secondary surgical treatment of eyes following massive SCH.

PATIENTS AND METHODS

We treated 10 patients suffering from massive SCH by combined radial sclerotomies for suprachoroidal drainage and vitrectomy with use of perfluorocarbon and instillation of silicone oil. We analyzed the clinical characteristics, visual acuity and anatomical status before and after secondary treatment.

RESULTS

Visual acuity of all eyes suffering from SCH was light perception. Postoperatively five patients with SCH showed either no improvement of function or visual acuity of counting fingers. An increase in visual acuity to maximal 0.1 was seen in four eyes; one patient achieved 0.6. With a minimum of 6 months' follow-up, four eyes developed hypotony, two eyes became phthisical, and in two eyes recurrent traction retinal detachment occurred.

CONCLUSIONS

Secondary treatment by combined suprachoroidal drainage by sclerotomies and vitrectomy should be performed to minimize the damaging effect of choroidal hemorrhage.

[Penetrating and perforating eye injuries with foreign bodies during motorized brush-cutting while wearing head protection gear]

BACKGROUND

Protective clothing is prescribed concerning gloves, shoes, protective trousers and a helmet for protection of hearing and the face during brush-cutter work.

PATIENTS AND METHODS

Seven patients were observed in a time period from 1994 to 1998. Mostly a nylon head protection had been used. The side of the helmet has no protection shield. The 1- to 4-mm large foreign bodies passed the head protection shield from the side or by entering through the holes of the nylon mesh which may be not small enough to stop the foreign body. A pars plana vitrectomy with foreign body removal was performed after primary wound repair.

RESULTS

An endophthalmitis was diagnosed in two patients after primary wound treatment. In these cases, a pars plana vitrectomy and antibiotic instillation was performed. In 5 patients visual acuity increased postoperatively. We measured a postoperative visual acuity from 1/50 to 1.6. The development of proliferative vitreoretinopathy with retinal detachment in 4 patients was the main complication observed after pars plana vitrectomy.

CONCLUSIONS

A cosmetically satisfactory appearance of the injured eye was reached by pars plana vitrectomy in all patients. Anatomic and functional success was reached in most of the patients. For prophylaxis, a head-protection seems not safe enough. The additional usage of eye protection glasses may be imperative for the prevention of these eye injuries.

[Management of submacular hemorrhage by tissue plasminogen activator and SF(6) gas injection]

The formation of platelet-fibrin clots causes degeneration of foveolar photoreceptors by subretinal hemorrhage.

PATIENTS

Twenty-two patients with submacular hemorrhages were treated by intravitreal injection of 50 microg tpa and 0.5 ml SF(6) gas within 1 h. Biomicroscopy, fundus photography and fluorescein angiography were performed pre- and postoperatively. Further multifocal electroretinograms were recorded.

RESULTS

The subfoveolar hemorrhages were dissoluted and displaced out of the macular region. The visual acuity increased in 18 cases and ranged from hand movement and 0.3 to values between 1/10 and 0.5.

CONCLUSIONS

Toxic and hypoxic damage of foveolar photoreceptors by subretinal hemorrhage can be prevented by early and minimal invasive fibrinolytic therapy. After localization of choroidal neovascularizations, treatment by focal laser coagulation is possible in some cases.

[Hyperplastic persistent pupillary membrane--surgical procedure]

BACKGROUND

Persistent pupillary membranes are a common congenital anomaly seen in 95% of neonates. Extensive persistent pupillary membranes, occluding the visual axis and resulting in reduced visual acuity, are relatively uncommon.

CASE REPORT

A 4-year-old male infant was seen in our hospital with reduced visual acuity of his left eye. Slit-lamp examination revealed a dense, extensive, persistent pupillary membrane associated with anterior polar cataract. We performed an excision of the pupillary membrane, lens aspiration of the lens material, posterior capsulorhexis, anterior vitrectomy and placement of a posterior chamber-intraocular lens in the capsular bag. 8 weeks after operation visual acuity improved to 0.25.

CONCLUSIONS

Dense pupillary membranes associated with polar cataract require early surgical treatment. Membranectomy, lens aspiration and implantation of an intraocular lens clear the visual axis and optimize the treatment of amblyopia.

Regulation of Hoxa2 in cranial neural crest cells involves members of the AP-2 family

Hoxa2 is expressed in cranial neural crest cells that migrate into the second branchial arch and is essential for proper patterning of neural-crest-derived structures in this region. We have used transgenic analysis to begin to address the regulatory mechanisms which underlie neural-crest-specific expression of Hoxa2. By performing a deletion analysis on an enhancer from the Hoxa2 gene that is capable of mediating expression in neural crest cells in a manner similar to the endogenous gene, we demonstrated that multiple cis-acting elements are required for neural-crest-specific activity. One of these elements consists of a sequence that binds to the three transcription factor AP-2 family members. Mutation or deletion of this site in the Hoxa2 enhancer abrogates reporter expression in cranial neural crest cells but not in the hindbrain. In both cell culture co-transfection assays and transgenic embryos AP-2 family members are able to trans-activate reporter expression, showing that this enhancer functions as an AP-2-responsive element in vivo. Reporter expression is not abolished in an AP-2(alpha) null mutant embryos, suggesting redundancy with other AP-2 family members for activation of the Hoxa2 enhancer. Other cis-elements identified in this study critical for neural-crest-specific expression include an element that influences levels of expression and a conserved sequence, which when multimerized directs expression in a broad subset of neural crest cells. These elements work together to co-ordinate and restrict neural crest expression to the second branchial arch and more posterior regions. Our findings have identified the cis-components that allow Hoxa2 to be regulated independently in rhombomeres and cranial neural crest cells.

The REMATCH trial: rationale, design, and end points. Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure

BACKGROUND

Because left ventricular assist devices have recently been approved by the Food and Drug Administration to support the circulation of patients with end-stage heart failure awaiting cardiac transplantation, these devices are increasingly being considered as a potential alternative to biologic cardiac replacement. The Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure (REMATCH) trial is a multicenter study supported by the National Heart, Lung, and Blood Institute to compare long-term implantation of left ventricular assist devices with optimal medical management for patients with end-stage heart failure who require, but do not qualify to receive cardiac transplantation.

METHODS

We discuss the rationale for conducting REMATCH, the obstacles to designing this and other randomized surgical trials, the lessons learned in conducting the multicenter pilot study, and the features of the REMATCH study design (objectives, target population, treatments, end points, analysis, and trial organization).

CONCLUSIONS

We consider what will be learned from REMATCH, expectations for expanding the use of left ventricular assist devices, and future directions for assessing clinical procedures.

Clinical application of a new disposable lithotripter: a prospective multicenter study

BACKGROUND

Mechanical lithotripsy has become a well-accepted method of bile duct stone fragmentation and removal. The Olympus lithotripter (Olympus American, Melville, NY) is the standard reusable lithotripter at the institutions that participated in this study. A disposable device with a preassembled pistol grip may perform equally well and facilitate operation.

METHODS

Twenty patients with bile duct stones were evaluated as part of a multicenter prospective study. Data were obtained regarding stone size and number, bile duct diameter, and configuration, ease of cannulation, basket function, stone capture and crushing success, and complications.

RESULTS

The maximum stone size averaged 16.5 +/- 1.2 mm (range 10 to 30 mm). Sixteen patients had multiple stones (median 5, range 2 to 12). The mean bile duct diameter was 20.5 +/- 1.5 mm (range 12 to 38 mm). Cannulation was successful in all within 5 attempts. Basket deployment failed in 1 patient because of stone size and the basket was misshapen in 14. Bile duct clearance was complete in 16 subjects (80%), incomplete in 2 patients, and failed in 2 patients. Abnormal duct configuration (sigmoid, stricture) was noted in 2 of 4 patients with failed capture and 7 of 16 patients with successful clearance. No statistically significant difference was observed between the bile duct diameter, maximum stone size, number of stones, and successful clearance.

CONCLUSION

The disposable lithotripter is easy to use and, compared with the published results for the reusable lithotripter, performs almost as well.

Dormancy of mammary carcinoma after mastectomy

BACKGROUND

The longest interval between primary treatment of breast cancer and tumor recurrence, i.e., the limit of breast cancer dormancy, defines the appropriate length of follow-up, the effectiveness of treatment, and curability (no excess mortality risk for patients relative to the general population) for the disease. To determine this limit, we analyzed long-term follow-up data from patients who underwent a radical mastectomy during a four-decade period at the University of Chicago Hospitals.

METHODS

For 1547 patients operated on during the period from 1945 through mid-1987, the number of recurrences and deaths occurring within each postoperative year were tabulated, and the hazard rate for first recurrence or death from breast cancer was estimated by use of the actuarial method. The excess mortality rate was calculated for successive 5-year intervals, beginning at the time of mastectomy, by use of U.S. life tables and matching on the basis of age, race, and sex.

RESULTS

Most recurrences occurred within the first 10 years after mastectomy. Recurrences were rare after 20 years; only one recurrence was reported among 192 patients followed for 26-45 years. Patients who had a recurrence within 5 years following mastectomy had shorter subsequent survival times than those whose recurrence appeared after 5 years (two-sided P = .0001). The excess death rate increased with pathologic stage of the primary tumor. Overall, there was evidence of excess mortality up to 20 years postsurgery (two-sided P = .009).

CONCLUSIONS

The limit of breast cancer dormancy in this patient population appears to be between 20 and 25 years. After this time, recurrences were rare, and the mortality rate was no longer statistically significantly different from that of the general population. Patients surviving to this time without evidence of recurrence or contralateral breast cancer are probably cured.

[Pars plana vitrectomy in Borrelia burgdorferi endophthalmitis]

BACKGROUND

Ocular manifestations of Lyme borreliose present with unusual forms of conjunctivitis, keratitis, optic nerve disease, uveitis, vitritis and rarely endophthalmitis.

CASE REPORT

A 57-year-old man working as logger in Sax-ony-Anhalt suffering from an endophthalmitis on his left eye was referred to us. The vision of his left eye was intact light perception and hand motions. The slit-lamp examination revealed severe inflammation of the anterior chamber with hypopyon, posterior synechiae, and opacity of the posterior lens capsule. Funduscopy showed no red reflex, no retinal details. In the local hospital serum analysis was performed and showed in Western-Blot IgM- and IgG-antibodies against Borrelia burgdorferi. Despite of intravenous application of ceftriaxon for 14 days panuveitis persisted, and endophthalmitis developed when antibiotic therapy was finished.

RESULTS

During pars plana vitrectomy a sharply delineated cystic lesion containing yellowish fluid was revealed, and creamy yellow fluid was aspirated. Microscopically in hematoxylineosin stained slides of the aspirate structures consistent with Borrelia burgdorferi were found. Postoperatively vision increased to 1/15. Despite of a second intravenous ceftriaxon treatment for 14 days we observed a retinal vasculitis in the follow up of 6 months.

CONCLUSIONS

Despite intravenous ceftriaxon-therapy borrelia burgdorferi must have survived in the vitreous body. Further investigations are required with respect to the use of other antibiotics or immunosuppressives.

Primary basal cell carcinoma of the caruncle

We describe a 24-year-old man with primary basal cell carcinoma of the caruncle. Clinically the lesion was a whitish, slightly prominent nodule surrounded by fine vessels. No associated cutaneous lesion and no connection to the surrounding skin was present. The lesion was subsequently completely excised, and histopathological examination revealed a solid-cystic basal cell carcinoma of the caruncle. Primary basal cell carcinoma of the caruncle is an extremely rare but distinct entity. To our knowledge, review of the literature has not demonstrated a previous photographically documented case of primary basal cell carcinoma of the caruncle.