Therapeutic limitations of argon laser trabeculoplasty.

Sixty-one patients (82 eyes) were studied after argon laser trabeculoplasty (ALT) to determine the lasting efficacy of such treatment. This investigation, now in its fourth year, was prospective, and the information derived was analysed with the aid of a computer. Success was defined as intraocular pressure (IOP) below baseline (22 mmHg). The mean follow-up time was 24.5 months, when the success rate was 74% compared with 75% at three months. Success declined to 45% at 42 months. No significant difference was noted when (a) first lasered eyes of all patients and those fellow eyes treated were analysed separately, (b) when right and left eyes were analysed separately, nor (c) when patients were divided into two treatment groups, (I) 100 burns at 1 W, and (II) 65 burns at 850 mW. Eight of 11 eyes showed progressive postlaser field loss despite below-baseline intraocular pressures. ALT is an alternative to carbonic anhydrase inhibitor therapy, with a success rate of 66.7% at two years. However, repeat ALT was successful in only 25% of patients seven months after treatment.     

Sensitivity of intracellular signals responsible for cell cycle progression to cyclosporine.

Within the cascade of intracellular activation signals triggering T lymphocyte effector response to alloantigen is a cytoplasmic protein, ADR, that activates DNA replication in isolated nuclei. Quantitative changes in ADR (exclusive to activated cells) regulate cell cycle progression and may indicate changes in intracellular proliferative control. The present communication documents that inhibition of ADR activity reflects the in vitro immunosuppressive effects of Cyclosporine. CsA inhibition of both proliferation and generation of ADR was concentration-dependent and occurred only in the G0 phase of the cell cycle. Drug addition did not affect G1 cells. ADR generation was inhibited both by CsA and by PGE2 alpha, possibly via effects on calcium-dependent activation pathways confined to G0/G1 transition. On the other hand, ADR generation was not inhibited by the immunosuppressive agents 6-mercaptopurine, Enisoprost (a PGE1 analog), or FK506. ADR activity was sensitive to aprotinin, which typically inhibits serine proteases. Using an enzymatic assay to quantitate serine protease activity (SPA) following PHA stimulation revealed that ADR content inversely correlated with SPA: ADR was only present in activated cells; SPA was highest in resting cells and decreased after PHA stimulation. The PHA-induced fall in SPA activity was inhibited by CsA, consistent with the failure to generate ADR. Like ADR, SPA was sensitive to PGE2 alpha and quantitatively unaffected by 6-mercaptopurine, Enisoprost, or FK506. Thus, ADR and SPA may represent opposing components of a cytoplasmic signaling cascade the balance of which reflects the level of immunosuppression, and thus represents a focus for in vitro evaluation of the immunologic response of allografted patients to cyclosporine.     

Complications associated with alloplastic implants used in orbital fracture repair.

BACKGROUND: The treatment of orbital wall fractures involves observation and/or surgical reduction with repositioning of herniated orbital tissues. To prevent reherniation of tissue and development of enophthalmos, the orbital floor or wall defect is commonly covered with an alloplastic implant. Complications associated with these implants are infrequent and generally appear as isolated case reports. METHODS: The authors reviewed the files of four consultative oculoplastic surgeons and searched for individuals with complications secondary to their alloplastic implants used during orbital fracture repair. FINDINGS: Seventeen patients were identified with a variety of complications related to their alloplastic implant. CONCLUSION: Although these implants are relatively inert and develop a fibrous capsule walling them off from the surrounding orbit, they remain foreign bodies and are thus subject to possible complications at any time. The authors review the spectrum of complications occurring with various alloplastic implants.     

HLA-DR expression in macaque neuroendothelial cells in vitro and during SIV encephalitis

HLA-DR expression in neuroendothelial cells (NEC) was studied during the course of SIV encephalitis in rhesus monkeys. HLA-DR determinants were detected on NEC in monkeys with SIV encephalitis, but not in control animals. In situ hybridization with an SIV probe indicated that HLA-DR expression was not a consequence of SIV replication within NEC. Cultured rhesus NEC stimulated with gamma interferon expressed HLA-DR to a higher degree than cultured brain fibroblasts or astrocytes. These data support the contention that NEC participate in retrovirus-induced inflammation and autoimmunity within the central nervous system.     

Functional restoration in chronic low back pain

Conventional treatments have not slowed down the ever expanding low back pain (LBP) problem. Traditional treatment has most probably contributed to the growth of the problem. Therefore, in a search for new solutions, 'functional restoration' has been devised. In connection with chronic LBP the term has been associated with a full-day program lasting from 3 to 5 weeks. it includes multidisciplinary treatment of patients in groups with intensive physical and ergonomic training, psychological pain management, back school, as well as teaching in social/work related issues. The key concepts are 'acceptance of the pain', 'activity', 'self-responsibility', 'multidisciplinary' and 'quantitative functional evaluation (QFE)'. The latter is aimed so that the participants can feel the physical improvement, encouraging them to be able to go back to work, or at least to lead a more active life style. Several controlled studies suggest a lasting effect in terms of regaining their ability to work and improving pain behavior for a good part of disabled chronic LBP patients. However, it is noteworthy that randomized studies seemingly show poorer results than studies not employing randomized controls.     

PCR amplification introduces errors into mononucleotide and dinucleotide repeat sequences.

The polymerase chain reaction (PCR) is used universally for accurate exponential amplification of DNA. We describe a high error rate at mononucleotide and dinucleotide repeat sequence motifs. Subcloning of PCR products allowed sequence analysis of individual DNA molecules from the product pool and revealed that: (1) monothymidine repeats longer than 11 bp are amplified with decreasing accuracy, (2) repeats generally contract during PCR because of the loss of repeat units, (3) Taq and proofreading polymerase Pfu generate similar errors at mononucleotide and dinucleotide repeats, and (4) unlike the parent PCR product pool, individual clones containing a single repeat length produce no "shadow bands". These data demonstrate that routine PCR amplification alters mononucleotide and dinucleotide repeat lengths. Such sequences are common components of genetic markers, disease genes, and intronic splicing motifs, and the amplification errors described here can be mistaken for polymorphisms or mutations.