Femtosecond dovetail penetrating keratoplasty: surgical technique and case report

AIM

To report a dovetail configuration for femtosecond-enabled penetrating keratoplasty (PK) with the corresponding laser parameters and suturing technique.

METHODS

A 40-year-old man, with a history of penetrating corneal injury as a child, underwent femtosecond-enabled dovetail keratoplasty, anterior vitrectomy and secondary intraocular lens suturing to repair his corneal scar and aphakia. A partial thickness dovetail pattern was performed in the recipient cornea using the femotsecond laser. The posterior side-cut was initiated approximately 100 microm anterior to the Descemet membrane and extended obliquely towards the outer edge of a ring lamellar cut, positioned at approximately 300 microm stromal depth. The anterior side-cut was extended from the internal edge of the ring lamellar cut to the corneal surface. Using an artificial chamber, the femtosecond laser was used to create a full-thickness 0.2 mm oversized femtosecond-enabled dovetail trephination with similar anterior lamellar depth (approximately 300 microm). Wound closure, using interrupted 10-0 nylon sutures, was guided by preplaced radial alignment laser microincisions and tongue-in-groove midstromal suture positioning.

RESULTS AND DISCUSSION

Excellent alignment and stability of the donor and recipient tissue were observed immediately postoperatively and 5 months after surgery. The feasibility of the "dovetail" pattern of PK and the tongue-in-groove suture positioning is demonstrated.

IMVP-16/Pd followed by high-dose chemotherapy and autologous stem cell transplantation as a salvage therapy for refractory or relapsed peripheral T-cell lymphomas

The present study aimed to analyse the treatment outcome of IMVP-16/Pd (ifosfamide, methotrexate, etoposide and prednisone) followed by high-dose chemotherapy and autologous stem cell transplantation (HDC/ASCT) for patients with peripheral T-cell lymphomas (PTCLs) who were previously treated with CHOP. Since 1995, 32 PTCL patients were treated with IMPV-16/Pd. Nine of 32 patients achieved a response (5 demonstrating complete response (CR) and 4 partial response), with an overall response rate of 28.1% (95% onfidence interval 0.12-0.45). Considering histopathologic subtypes, 3 of 4 relapsed natural killer (NK)/T-cell lymphoma patients (75%) achieved CR, but only 1 of 6 in non-NK/T-cell lymphoma patients (16.7%) achieved CR (P = 0.19). Six of 9 IMVP-16/Pd sensitive patients underwent HDC/ASCT. Three of them relapsed after 3, 4 and 15 months, respectively, of HDC/ASCT. Estimated 3-year overall survival and progression-free survival rates were 14.2% and 12.2%, respectively. Multivariate analysis revealed that responsiveness to first-line CHOP was a significant prognostic factor (P < 0.05). These results indicate that IMVP-16/Pd followed by HDC/ASCT appears to be an effective salvage regimen, especially for NK/T-cell lymphoma.

Ethanol preference in C. elegans

Caenorhabditis elegans senses multiple environmental stimuli through sensory systems and rapidly changes its behaviors for survival. With a simple and well-characterized nervous system, C. elegans is a suitable animal model for studying behavioral plasticity. Previous studies have shown acute neurodepressive effects of ethanol on multiple behaviors of C. elegans similar to the effect of ethanol on other organisms. Caenorhabditis elegans also develops ethanol tolerance during continuous exposure to ethanol. In mammals, chronic ethanol exposure leads to ethanol tolerance as well as increased ethanol consumption. Ethanol preference is associated with the development of tolerance and may lead to the development of ethanol dependence. In this study, we show that C. elegans is a useful model organism for studying chronic effects of ethanol, including the development of ethanol preference. We designed a behavioral assay for testing ethanol preference after prolonged ethanol exposure. Despite baseline aversive responses to ethanol, animals show ethanol preference after 4 h of pre-exposure to ethanol and exhibit significantly enhanced preference for ethanol after a lifetime of ethanol exposure. The cat-2 and tph-1 mutant animals have defects in the synthetic enzymes for dopamine and serotonin, respectively. These mutants are deficient in the development of ethanol preference, indicating that dopamine and serotonin are required for this form of behavioral plasticity.

National survey of physicians practice patterns: Fertility preservation and cancer patients

CRA9508

Background: Addressing the impact of cancer treatment on fertility is a high priority in providing quality cancer care to patients of childbearing age. Evidence suggests less than 50% of patients receive adequate fertility information prior to cancer treatment. This study assessed the practice patterns of physicians and identified perceptions of barriers to communication about fertility. Methods: A 37 item survey was developed by a review of the literature and previous qualitative interviews. A random sample of physicians from the American Medical Association Masterfile was stratified by board specialty related to oncology. Three waves of surveys were distributed across the United States. The domains of the survey included demographics, knowledge, attitudes and practice behaviors related to FP with patients of childbearing age. Results: Of 1,979 physicians identified, a total of 613 physicians completed the survey, yielding a 33% response rate among oncologists. Oncologists with favorable attitudes towards FP were 4.9 times more likely to discuss the impact of cancer treatment on future fertility than those who have unfavorable attitudes. GYN or Medical/Hematological oncologists were 2.1 times more likely than other specialists to report feeling comfortable discussing FP with their patients. The majority of oncologists reported discussing FP with patients and indicated the primary barrier to discussion was a patient too ill to delay treatment. However, less than 25% of oncologists report referring patients for FP and only 38% report knowledge of the ASCO guidelines suggesting oncologists should discuss FP and refer all patients of childbearing age. Less than 25% of physicians surveyed reported distributing educational materials regarding FP. Conclusions: The majority of physicians in this survey report discussing FP; however they are not consulting specialists or providing educational materials to their patients. Future research will include the development of physician and nurse training curricula and interventions to facilitate discussion of FP between physicians and cancer patients.

No significant financial relationships to disclose.

Mechanisms in knockout reactions

We report the first detailed study of the relative importance of the stripping and diffraction mechanisms involved in nucleon knockout reactions, by the use of a coincidence measurement of the residue and fast proton following one-proton knockout reactions. The measurements used the S800 spectrograph in combination with the HiRA detector array at the NSCL. Results for the reactions 9Be(9C,8B+X)Y and 9Be(8B,7Be+X)Y are presented and compared with theoretical predictions for the two reaction mechanisms calculated using the eikonal model. The data show a clear distinction between the stripping and diffraction mechanisms and the measured relative proportions are very well reproduced by the reaction theory. This agreement adds support to the results of knockout reaction analyses and their applications to the spectroscopy of rare isotopes.

Dendritic cells engineered to secrete anti-GITR antibodies are effective adjuvants to dendritic cell-based immunotherapy

A number of monoclonal antibodies (mAbs) have been studied for their ability to enhance immune responses. Although these antibodies are effective in pre-clinical and clinical studies, they are costly and have occasionally been associated with adverse effects such as autoimmunity and cytokine storm. Numerous studies have shown that treatment of mice with an agonistic mAb, clone DTA-1, targeting murine glucocorticoid-induced tumor necrosis factor receptor (GITR) results in enhanced immune responses in tumor-bearing animals. Herein, we evaluate the novel approach of transfecting dendritic cell (DC) with mRNA encoding the heavy and light chain of the anti-GITR mAb. We show the induction of significantly enhanced tumor immunity by vaccinating with a combination of anti-GITR-secreting DC and tumor antigen-presenting DC. This enhancement is comparable to that seen with systemically delivered mAb along with the antigen-presenting DC. Importantly, when anti-GITR was delivered using RNA-transfected DC, we observed no evidence of autoimmune hypopigmentation in any tumor-free mice. We also show enhanced induction of cytotoxic T-lymphocyte responses, which is only observed when the antigen-presenting and antibody-secreting DC are co-injected at the same site. To illustrate the broad utility of this strategy, we show that DC transfected with mRNA encoding GITR-ligand/Fc fusion protein is also an effective tumor vaccine adjuvant.

Prodrug delivery of novel PTP1B inhibitors to enhance insulin signalling

A growing percentage of the population is resistant to two key hormones - insulin and leptin - as a result of increased obesity, often leading to significant health consequences such as type 2 diabetes. Protein tyrosine phosphatase 1B (PTP1B) is a key negative regulator of signalling by both of these hormones, so that inhibitors of this enzyme may provide promise for correcting endocrine abnormalities in both diabetes and obesity. As with other tyrosine phosphatases, identification of viable drug candidates targeting PTP1B has been elusive because of the nature of its active site. Beginning with novel phosphotyrosine mimetics, we have designed some of the most potent PTP1B inhibitors. However, their highly acidic structures limit intrinsic permeability and pharmacokinetics. Ester prodrugs of these inhibitors improve their drug-like properties with the goal of delivering these nanomolar inhibitors to the cytoplasm of cells within target tissues. In addition to identifying prodrugs that is able to deliver active drugs into cells to inhibit PTP1B and increase insulin signalling, these compounds were further modified to gain a variety of cleavage properties for targeting activity in vivo. One such prodrug candidate improved insulin sensitivity in ob/ob mice, with lowered fasting blood glucose levels seen in the context of lowered fasting insulin levels following 4 days of intraperitoneal dosing. The results presented in this study highlight the potential for design of orally active drug candidates targeting PTP1B, while also delineating the considerable challenges remaining.

Adding nutritional value to meat and milk from pasture-fed livestock

Staple meat and milk provide excellent nutrition, but when traditional foods and ingredients are tailored to meet the particular nutritional or lifestyle demands of a population they become even more attractive and valuable. These foods can be considered as delivery systems for health-promoting nutrients. Nutritional improvement of meat and milk can be achieved several ways, preferably by making desirable changes on-farm to directly improve the food without subsequent manipulations. Scope for these changes is limited by animal homeostasis, but alternatives may be less desirable. Methods in vivo that suit typical pastoral farming practice and can complement the solving of animal health and production problems include: selection of traits or phenotypes; specialty diets; long-acting parenteral supplements; and modification of ruminal microflora. Successful techniques to increase the concentration of calcium, selenium, iodine and iron in milk or meat are described. Manipulations to change composition are only one part of bringing tailored foods to market. Commercial realisation of these new products needs the initiative and collaboration of scientists, veterinarians, growers and producers responding to market pull. The uptake of future biotechnologies to capture more value inside the farm gate will also be required if the pastoral industry in New Zealand is to sustain a global competitive advantage.