Myopia Control Efficacy and Long-Term Safety of a Novel Orthokeratology Lens (MESOK Study)-A Randomized Controlled Clinical Trial Combining Clinical and Tear Proteomics Data

Myopia control efficacy and long-term safety of the Breath-O-Correct orthokeratology (OK) lens was evaluated in a 2-year randomized, single vision (SV) spectacle lens-controlled, single-blind clinical trial combining clinical and tear proteomics data. A total of 71 children (43 OK, 9.8 ± 1.3 years; 28 SV, 9.5 ± 1.4 years) completed the 2-year study. Axial length (AL), cycloplegic refraction, clinical safety parameters (best-corrected visual acuity, central cornea thickness, corneal endothelial health, ocular surface disease index), and quantitative tear proteomics were evaluated by masked examiners. Mean 2-year-normalized AL elongations in the OK and SV groups differed significantly (p = 0.03) and were 0.37 ± 0.37 mm and 0.60 ± 0.41 mm, respectively. OK-mediated myopia control efficacy was 37.1%. No significant difference was found in clinical safety parameters of both groups (p > 0.10), except for a thinner central corneal thickness in the OK group (p = 0.01). Proteomics revealed modest OK lens-mediated effects on immune response proteins, including an increased abundance of haptoglobin at 6 and 12 months and a decreased abundance of two proteins (neutrophil defensin 3 and histone 4) at 6 months. The changes were further validated using a high-resolution multiple-reaction monitoring (MRM^HR) mass spectrometry. In summary, the Breath-O-Correct OK lens significantly reduced AL elongation in schoolchildren without adverse clinical effects or subclinical inflammatory responses.

Safety of Reduction Mammaplasty and Mastopexy After Breast Conservation Therapy and Radiation Therapy: A Case Series

BACKGROUND

Conservative surgery and radiotherapy (CS + RT) have become the standard of care for early-stage breast cancer as an alternative to mastectomy. With the increasing rate of obesity and incidence of macromastia, surgeons increasingly encounter patients with a history of breast radiation desiring breast reduction. However, elective breast surgery after irradiation remains to be controversial due to known adverse effects of radiation, especially on wound healing, and unknown effects of lumpectomy on traditional pedicle choices. Herein, we present our experiences and outcomes of reduction mammaplasties and mastopexies in patients with breast cancer previously treated with CS + RT.

METHODS

Between 2009 and 2020, 13 patients undergoing reduction mammaplasty or mastopexy, who have previously underwent CS + RT with or without axillary surgery, were included in this study. Surgical techniques and complications, including delayed wound healing, infection, fat necrosis, and nipple-areolar necrosis, were recorded and analyzed based on the irradiated versus nonirradiated sides.

RESULTS

Of the 13 patients, delayed wound healing occurred in 7% on the irradiated side and 15% on the nonirradiated sides (P > 0.05). No significant correlation was observed between the number of complications and time of elective breast surgery from the last radiation therapy. Complications between irradiated and nonirradiated breasts did not significantly differ in both the reduction mammaplasty and mastopexy groups.

CONCLUSIONS

Reduction mammaplasty and mastopexy in patients with a history of lumpectomy and breast irradiation can be safely performed and should be considered in those experiencing macromastia or asymmetry post-CS + RT.

Integrated Mass Spectrometry Reveals Celastrol As a Novel Catechol-O-methyltransferase Inhibitor

Natural product celastrol is known to have various biological activities, yet its molecular targets that correspond to many activities remain unclear. Here, we used multiple mass-spectrometry-based approaches to identify catechol-O-methyltransferase (COMT) as a major binding target of celastrol and characterized their interaction comprehensively. Celastrol was found to inhibit the enzymatic activity of COMT and increased the dopamine level in neuroendocrine chromaffin cells significantly. Our study not only revealed a novel binding target of celastrol but also provided a new scaffold and cysteine hot spot for developing new generation COMT inhibitors in combating neurological disorders.

Preparation of Hard Tissues Like Bone or Cartilage for Shotgun Mass Spectrometry Analysis of the Proteome

Proteomic analyses of intervertebral discs (IVDs) reveal information for understanding the fundamentals of biological processes and pathogenesis but also provide insights for novel pharmaceutical development. Sensitive mass spectrometry techniques and bioinformatics have advanced the detection and identification of proteins from any sample. Due to the challenges of catastrophic sample-loss artifacts during hard-tissue extraction, however, many researchers have omitted the cartilage endplates of IVDs for protein extraction, analyzing only the cellular components of the annulus fibrosus and/or nucleus pulposus. The full proteomic picture of IVDs is compromised without extracting proteins from intact IVDs. Here, we describe a novel preparation method using snap-freeze grinding, which allows for mechanical disruption and customized chemical lysis of hard tissues such as bone or cartilage. This method replaces the time-consuming and insufficient conventional tissue homogenization methods. Sample loss and contamination could be minimized during proteolysis by using an in-solution protein digestion and desalting procedure. We demonstrate excellent proteome coverage with intact mouse IVDs by analyzing samples in a hybrid quadrupole time-of-flight tandem mass spectrometer. © 2021 Wiley Periodicals LLC.

Integrating Clinical Data and Tear Proteomics to Assess Efficacy, Ocular Surface Status, and Biomarker Response After Orthokeratology Lens Wear

Purpose

This study evaluated the efficacy and ocular surface status of Breath-O Correct, novel orthokeratology (OK) lenses, worn overnight for 3 months. Lens-induced changes in the tear proteome were evaluated.

Methods

Thirty-one subjects, aged 19 to 26 years with refractive error from -1.00 to -5.00 D, were randomly assigned 1:1 to the treatment or control group. Refraction, visual acuity, corneal integrity, biomechanics and endothelial health, ocular surface changes, and subjective symptoms were assessed at the baseline, one-month, and three-month visits. The tear proteome was characterized over time using sequential window acquisition of all theoretical ion spectra mass spectrometry.

Results

Lenses improved uncorrected visual acuity and reduced spherical powers with similar efficacy to other OK lenses. Significant reductions (P < 0.05) in corneal hysteresis (11.12 ± 1.12 to 10.38 ± 1.36 mm Hg) and corneal resistance factor (11.06 ± 1.32 to 9.90 ± 1.45 mm Hg) were observed in the treatment group after one month of lens wear, whereas other assessed factors remained unchanged. Thirteen and eight differentially expressed proteins were found after one month and three months of lens wear, respectively. Two proteins (proline-rich protein 27 and immunoglobulin V regions) were differentially expressed at both visits.

Conclusions

Over a three-month period, Breath-O Correct lenses were overall safe, well tolerated, efficacious in refractive power reduction, and comparable with other OK lenses. Furthermore, their use caused only minor noninflammatory protein expression changes in the tear proteome.

Translational Relevance

This study investigated the safety of orthokeratology contact lenses on the ocular surface in molecular aspects and standard clinical parameters.

Differential Retinal Protein Expression in Primary and Secondary Retinal Ganglion Cell Degeneration Identified by Integrated SWATH and Target-Based Proteomics

To investigate the retinal proteins associated with primary and secondary retinal ganglion cell (RGC) degeneration and explore their molecular pathways, SWATH label-free and target-based mass spectrometry was employed to identify the proteomes in various retinal locations in response to localized optic nerve injury. Unilateral partial optic nerve transection (pONT) was performed on adult Wistar rats and their retinas were harvested 2 weeks later. To confirm the separation of primary and secondary RGC degeneration, immunohistochemistry of RNA binding protein with multiple splicing (RBPMS) and glial fibrillary acidic protein (GFAP) was performed on retinal whole-mounts. Retinal proteomes in the temporal and nasal quadrants were evaluated with high resolution hybrid quadrupole time-of-flight mass spectrometry (QTOF-MS), and SWATH-based acquisition, and their expression was compared to the corresponding retinal quadrant in contralateral control eyes and further validated by multiple reaction monitoring mass spectrometry (MRM-MS). A total of 3641 proteins (FDR < 1%) were identified using QTOF-MS. The raw data are available via ProteomeXchange with the identifier PXD026783. Bioinformatics data analysis showed that there were 37 upregulated and 25 downregulated proteins in the temporal quadrant, whereas 20 and five proteins were upregulated and downregulated, respectively, in the nasal quadrant, respectively (n = 4, p < 0.05; fold change ≥ 1.4-fold or ≤0.7). Six proteins were regulated in both the temporal and the nasal quadrants, including CLU, GFAP, GNG5, IRF2BPL, L1CAM, and CPLX1. Linear regression analysis indicated a strong association between the data obtained by means of SWATH-MS and MRM-MS (temporal, R² = 0.97; nasal, R² = 0.96). Gene ontology analysis revealed statistically significant changes in the biological processes and cellular components of primary RGC degeneration. The majority of the significant changes in structural, signaling, and cell death proteins were associated with the loss of RGCs in the area of primary RGC degeneration. The combined use of SWATH-MS and MRM-MS methods detects and quantifies regional changes of retinal protein expressions after localized injury. Future investigation with this integrated approach will significantly increase the understanding of diverse processes of progressive RGC degeneration from a proteomic prospective.

Combination atezolizumab, bevacizumab, pemetrexed and carboplatin for metastatic EGFR mutated NSCLC after TKI failure

INTRODUCTION

Acquired resistance to TKI is an important unmet need in the management of EGFR mutated lung cancer. Recent clinical trial IMPower150 suggested that combination approach with VEGF inhibitor, check point inhibitor immunotherapy and platinum-based chemotherapy was effective in oncogene driven lung cancer. The current trial examined the efficacy of a modified regimen in an EGFR mutated cohort.

METHODS

An open-labelled, single arm, phase II study was conducted in patients with EGFR mutated NSCLC who had progressed on at least one EGFR TKI. For those with T790M mutation, radiological progression on osimertinib was required for enrolment. Patients were treated with combination atezolizumab (1200 mg), bevacizumab (7.5 mg/kg), pemetrexed (500 mg/m2) and carboplatin (AUC 5) given once every 3 weeks until progression.

RESULTS

Forty patients were enrolled. Median age was 62 (range 45-76) years. More than one half (23/40, 57.5%) had progressed on osimertinib. PD-L1 expression was < 1% in 52.5%. Median follow-up time was 17.8 months. ORR was 62.5%. Median PFS was 9.4 months (95% CI: 7.6 - 12.1). One year OS was 72.5% (95% CI: 0.56-0.83). Treatment related grade 3 or above adverse events (AE) occurred in 37.5% (15/40). Immune-related AE occurred in 32.5% (13/40) patients. Quality of life measures of function and symptoms did not change significantly throughout the course of treatments. Post-trial rechallenge with EGFR TKI containing regimen resulted in PFS of 5.8 months (95% CI 3.9-10.0 months).

CONCLUSION

Combination approach of atezolizumab, bevacizumab, pemetrexed and carboplatin achieved promising efficacy in metastatic EGFR mutated NSCLC after TKI failure. The results were comparable with taxane based regimen of IMPower150 while toxicity profile was improved.

Ten-Year Clinical Outcomes of Acute Primary Angle Closure Randomized to Receive Early Phacoemulsification Versus Laser Peripheral Iridotomy

PURPOSE

To compare the 10-year clinical outcomes of eyes with acute primary angle closure (APAC) randomized to receive either early phacoemulsification or laser peripheral iridotomy (LPI).

METHODS

Sixty-two APAC patients, who underwent either early phacoemulsification (phaco group) or laser peripheral iridotomy (LPI group) in a previous randomized controlled trial, were invited for assessment 10 years after the interventions. The results of the 2 groups were compared.

RESULTS

Forty of 62 patients (64.5%; 19 in phaco group and 21 from LPI group) were examined. None of them underwent additional glaucoma procedure but 15 (71.4%) patients in the LPI group received lens extraction before this assessment. The mean follow-up duration was 10.7±0.7 years. The phaco group used less medication (0.16±0.37 vs. 0.76±1.09 bottle per eye, P=0.028), had less extensive anterior synechiae (120.0±116.12 vs. 244.3±139.8 degree, P=0.010), and greater mean Shaffer gonioscopy grading (1.79±0.84 vs. 1.40±0.87; P=0.021) than the LPI group. Five eyes had persistent intraocular pressure elevation of >21 mm Hg in 2 consecutive visits and 4 eyes had blindness (best-corrected visual acuity worse than 6/60 and/or central visual field of <20 degree) in the LPI group, compared with none in the phaco group (P=0.022 and 0.045, respectively). There was no significant difference in the mean intraocular pressure, best-corrected visual acuity, and the number of eyes with visual field progression.

CONCLUSION

At 10 years, APAC eyes that underwent early phacoemulsification required less medication, less peripheral anterior synechiae, lower incidence of intraocular pressure elevation and a lower incidence of blindness compared with APAC eyes that underwent initial LPI.

Occult Breast Carcinoma Is More Common in Women Undergoing Breast Reduction after Contralateral Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Occult breast carcinoma is occasionally found in breast reduction specimens. Although its incidence varies widely, there is a trend toward an increased incidence for women with a history of breast cancer. The authors performed a systematic review and meta-analysis of occult carcinoma incidence in breast reduction specimens.

METHODS

The MEDLINE and Embase databases were searched for peer-reviewed studies with no language restrictions for studies that recorded the incidence of occult carcinoma in breast reduction specimens. Cancer incidence per specimen was pooled for women with and without a history of breast cancer.

RESULTS

Forty-two studies were eligible for inclusion, of which 29 were quantitatively analyzed. The pooled incidence of carcinoma was higher within specimens from women with breast cancer (3.4 percent; 95 percent CI, 2.2 to 5.3 percent) than without (0.6 percent; 95 percent CI, 0.4 to 0.8 percent), and this increased likelihood was significant when populations were compared directly (OR, 6.02; 95 percent CI, 3.06 to 11.86; p < 0.0001).

CONCLUSIONS

Women with a history of breast cancer have an increased incidence of occult breast carcinoma within their breast reduction specimens compared with women with no breast cancer history. There is a need for preoperative radiology screening, counseling, and histopathology guidelines to ensure adequate diagnosis and management of these women.

Disorder in Pixel-Level Edge Directions on T1WI Is Associated with the Degree of Radiation Necrosis in Primary and Metastatic Brain Tumors: Preliminary Findings

BACKGROUND AND PURPOSE

Co-occurrence of local anisotropic gradient orientations (COLLAGE) is a recently developed radiomic (computer extracted) feature that captures entropy (measures the degree of disorder) in pixel-level edge directions and was previously shown to distinguish predominant cerebral radiation necrosis from recurrent tumor on gadolinium-contrast T1WI. In this work, we sought to investigate whether COLLAGE measurements from posttreatment gadolinium-contrast T1WI could distinguish varying extents of cerebral radiation necrosis and recurrent tumor classes in a lesion across primary and metastatic brain tumors.

MATERIALS AND METHODS

On a total of 75 gadolinium-contrast T1WI studies obtained from patients with primary and metastatic brain tumors and nasopharyngeal carcinoma, the extent of cerebral radiation necrosis and recurrent tumor in every brain lesion was histopathologically defined by an expert neuropathologist as the following: 1) "pure" cerebral radiation necrosis; 2) "mixed" pathology with coexistence of cerebral radiation necrosis and recurrent tumors; 3) "predominant" (>80%) cerebral radiation necrosis; 4) predominant (>80%) recurrent tumor; and 5) pure tumor. COLLAGE features were extracted from the expert-annotated ROIs on MR imaging. Statistical comparisons of COLLAGE measurements using first-order statistics were performed across pure, mixed, and predominant pathologies of cerebral radiation necrosis and recurrent tumor using the Wilcoxon rank sum test.

RESULTS

COLLAGE features exhibited decreased skewness for patients with pure (0.15 ± 0.12) and predominant cerebral radiation necrosis (0.25 ± 0.09) and were statistically significantly different (P < .05) from those in patients with predominant recurrent tumors, which had highly skewed (0.42 ± 0.21) COLLAGE values. COLLAGE values for the mixed pathology studies were found to lie between predominant cerebral radiation necrosis and recurrent tumor categories.

CONCLUSIONS

With additional independent multisite validation, COLLAGE measurements might enable noninvasive characterization of the degree of recurrent tumor or cerebral radiation necrosis in gadolinium-contrast T1WI of posttreatment lesions.

Breast Cancer-Related Lymphedema: Differentiating Fat from Fluid Using Magnetic Resonance Imaging Segmentation

BACKGROUND

Lymphedema is an iatrogenic complication after breast cancer treatment in which lymph fluid in the affected limb progresses to fat deposition and fibrosis that are amenable to liposuction treatment. Magnetic resonance imaging (MRI) for lymphedema can differentiate fat tissue from fluid, but estimating relative volumes remains problematic.

METHODS AND RESULTS

Patients underwent routine bilateral arm MRI both before and after liposuction for advanced lymphedema. The threshold-based level set (TLS) segmentation method was applied to segment the geometric image data and to measure volumes of soft tissue (fat, muscle, and lymph fluid) and bone. Bioimpedance testing (L-Dex^®) to detect extracellular fluid was also used. Volumes derived by using TLS or girth measurement were evaluated and showed consistent agreement, whereas L-Dex showed no significant reduction between pre- and postoperative measures. The percentage median volume difference between the affected and unaffected sides was 132.4% for girth measures compared with 137.2% for TLS (p = 0.175) preoperatively, and 99.8% and 98.5%, respectively (p = 0.600), postoperatively. MRI segmentation detected reductions in fat (median 52.6%, p = 0.0163) and lymph fluid (median 66%, p = 0.094), but the volumes of muscle and bone were relatively constant.

CONCLUSIONS

MRI imaging with TLS technology may be a useful tool to quantitatively measure fat tissue and fluid for patients with advanced lymphedema and may assist in the selection of eligible liposuction candidates at initial assessment and follow-up of patients who proceed with surgery.

Lipidomic Profiling of Adipose Tissue Reveals an Inflammatory Signature in Cancer-Related and Primary Lymphedema

Cancer-related and primary lymphedema (LE) are associated with the production of adipose tissue (AT). Nothing is known, however, about the lipid-based molecules that comprise LE AT. We therefore analyzed lipid molecules in lipoaspirates and serum obtained from LE patients, and compared them to lipoaspirates from cosmetic surgery patients and healthy control cohort serum. LE patient serum analysis demonstrated that triglycerides, HDL- and LDL-cholesterol and lipid transport molecules remained within the normal range, with no alterations in individual fatty acids. The lipidomic analysis also identified 275 lipid-based molecules, including triacylglycerides, diacylglycerides, fatty acids and phospholipids in AT oil and fat. Although the majority of lipid molecules were present in a similar abundance in LE and non-LE samples, there were several small changes: increased C20:5-containing triacylglycerides, reduced C10:0 caprinic and C24:1 nervonic acids. LE AT oil also contained a signature of increased cyclopropane-type fatty acids and inflammatory mediators arachidonic acid and ceramides. Interestingly C20:5 and C22:6 omega-3-type lipids are increased in LE AT, correlating with LE years. Hence, LE AT has a normal lipid profile containing a signature of inflammation and omega-3-lipids. It remains unclear, however, whether these differences reflect a small-scale global metabolic disturbance or effects within localised inflammatory foci.

Liposuction for Advanced Lymphedema: A Multidisciplinary Approach for Complete Reduction of Arm and Leg Swelling

Purpose

This research describes and evaluates a liposuction surgery and multidisciplinary rehabilitation approach for advanced lymphedema of the upper and lower extremities.

Methods

A prospective clinical study was conducted at an Advanced Lymphedema Assessment Clinic (ALAC) comprised of specialists in plastic surgery, rehabilitation, imaging, oncology, and allied health, at Macquarie University, Australia. Between May 2012 and 31 May 2014, a total of 104 patients attended the ALAC. Eligibility criteria for liposuction included (i) unilateral, non-pitting, International Society of Lymphology stage II/III lymphedema; (ii) limb volume difference greater than 25 %; and (iii) previously ineffective conservative therapies. Of 55 eligible patients, 21 underwent liposuction (15 arm, 6 leg) and had at least 3 months postsurgical follow-up (85.7 % cancer-related lymphedema). Liposuction was performed under general anesthesia using a published technique, and compression garments were applied intraoperatively and advised to be worn continuously thereafter. Limb volume differences, bioimpedance spectroscopy (L-Dex), and symptom and functional measurements (using the Patient-Specific Functional Scale) were taken presurgery and 4 weeks postsurgery, and then at 3, 6, 9, and 12 months postsurgery.

Results

Mean presurgical limb volume difference was 45.1 % (arm 44.2 %; leg 47.3 %). This difference reduced to 3.8 % (arm 3.6 %; leg 4.3 %) by 6 months postsurgery, a mean percentage volume reduction of 89.6 % (arm 90.2 %; leg 88.2 %) [p < 0.001]. All patients had improved symptoms and function. Bioimpedance spectroscopy showed reduced but ongoing extracellular fluid, consistent with the underlying lymphatic pathology.

Conclusions

Liposuction is a safe and effective option for carefully selected patients with advanced lymphedema. Assessment, treatment, and follow-up by a multidisciplinary team is essential.

A new approach to preexisting vertical midline abdominal scars with crossover DIEP flap breast reconstruction

Breast reconstruction using a free transverse rectus abdominis myocutaneous flap or a deep inferior epigastric perforator (DIEP) flap is a challenge in patients with a vertical midline abdominal scar due to the poor perfusion of the lower abdominal skin ellipse across the midline. In such patients, only one half of the abdominal skin ellipse can be used with certainty, and this limits the amount of tissue available for reconstructing the breast. Two cases of breast reconstruction in patients with a lower midline abdominal scar are presented using the DIEP flap, in which the poor perfusion across the midline scar was overcome by a technique of crossover anastomoses between the two deep inferior epigastric pedicles. Reliable perfusion of the entire lower abdominal skin ellipse was achieved. This crossover anastomoses technique overcomes the poor perfusion imposed by the vertical midline abdominal scar and enables DIEP flap breast reconstruction to be offered to women with midline abdominal scars.

Epidemiology and outcome of Candida bloodstream infection in an intensive care unit in Hong Kong

OBJECTIVE

To study the epidemiology of Candida bloodstream infection in the Intensive Care Unit.

DESIGN

Retrospective study.

SETTING

A 22-bed, mixed medical and surgical Intensive Care Unit of a 1400-bed university teaching hospital in Hong Kong.

PATIENTS

All adult patients (>18 years) who had at least one blood culture positive for Candida.

RESULTS

During the 9 years of the study period, there were 128 patients with episodes of candidaemia (point prevalence, 9.6 per 1000 Intensive Care Unit admissions), 72 entailed albicans candidaemia and 56 non-albicans candidaemia. Albicans was still the predominant species, but the incidence of tropicalis was increasing. The median lengths of hospital and Intensive Care Unit stays prior to taking of the culture revealing candidaemia were 15 and 6 days, respectively. In all, 61% of patients did not have Candida colonisation within 2 weeks of their candidaemia. The main anti-fungal agents used were fluconazole and amphotericin B, but only 89 (70%) of the patients received appropriate anti-fungal treatment. Intensive Care Unit and hospital mortalities were 70% and 78%, respectively. Patients who did not receive appropriate treatment within 3 days had a worse outcome than those who did.

CONCLUSIONS

Our data showed a high point prevalence of candidaemia in the Intensive Care Unit. Albicans was still the predominant species. Candidaemia occurred early during Intensive Care Unit stay, and a significant proportion of patients did not have prior fungal colonisation. Candidaemia in the Intensive Care Unit was associated with high morbidity and mortality. Many patients did not receive appropriately early anti-fungal therapy, and endured higher mortality than in the remainder.

Radiation-induced peripheral nerve neurofibromata in a patient receiving hypofractionated radiation therapy

Radiation-induced peripheral nerve tumor, in particular a benign entity such as a neurofibroma, is rare, with only a few cases being reported so far. We demonstrate a case of radiation-induced neurofibromata along the left cervical nerve roots in a man with a background of localized targeted hypofractionated radiation therapy as adjuvant treatment for left cervical nodal metastasis complicating nasopharyngeal carcinoma. The toxicity of high-dose radiation in a hypofractionated regime is also stressed.

Application of proteomic technology in eye research: a mini review

Proteomics is a rapidly growing research area for the study of the protein cognate of genomic data. This review gives a brief overview of the modern proteomic technology. In addition to general applications of proteomics, we highlight its contribution to studying the physiology of different ocular tissues. We also summarise the published proteomic literature in the broad context of ophthalmic diseases, such as cataract, age-related maculopathy, diabetic retinopathy, glaucoma and myopia. The proteomic technology is a useful research tool and it will continue to advance our understanding of a variety of molecular processes in ocular tissues and diseases.

Application of fluorescence difference gel electrophoresis technology in searching for protein biomarkers in chick myopia

The lens-induced myopia (LIM) in response to concave lens (negative lens) is a well established animal model for studying myopia development. However, the exact visual and neurochemical signaling mechanisms involving myopic eye growth are yet to be elucidated. The feasibility of applying a novel two-dimensional fluorescence difference gel electrophoresis technique for global protein profilings and a search for differential protein expressions in LIM were explored in the present study. Two-dimensional polyacrylamide gel electrophoresis was performed employing a "minimal Lysine labeling" approach and a reverse CyeDye experimental protocol using retinal tissue from chicks. The retinal protein profiles between myopic and control eyes were found to be very similar. More than a thousand protein spots could be detected on a 2D gel. Sixteen and ten protein spots were found to be up-regulated and down-regulated respectively in the myopic eyes according to our preset criteria with the inclusion of an internal pool standard. About 65% of those filtered spots could be successfully identified by peptide mass fingerprinting by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry . Most of the differentially expressed proteins were found to be related to cytoskeletal or oxidative functions. According to the prediction of subcellular locations, most of them (about 84%) were classified as cytoplasmic proteins. The cellular functions for those differentially expressed proteins were reported and their possible involvements in the compensated eye growth were discussed. We have optimized a workable protocol for the study of the differential retinal protein expressions in the LIM using 2D-DIGE approach which was shown to have a number of advantages over the traditional 2D electrophoresis technique.

A chick retinal proteome database and differential retinal protein expressions during early ocular development

Proteomics approach as a research tool has gained popularity in a growing number of basic and clinical researches. However, proteomic research has yet to gain significant momentum in eye research. Hence, we decided to build a retinal proteome database using postnatal retinal tissue from chick, a commonly used animal model in eye research. Employing 2-D gels with the coverage of 3-10 pH gradients, we were able to resolve hundreds of proteins from young chick retinae. Among them, 155 high abundant proteins were identified by Peptide Mass Fingerprinting (PMF) after the Matrix-Assisted Laser Desorption Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF MS). These proteins were then classified according to their functions. Making use of the retinal database, we were able to identify several differentially expressed proteins that might be involved in early retinal development by comparing the 2-DE maps of chick retinal tissues (3, 10, and 20 days after hatching). With the current proteomics approach, we not only documented the most abundant soluble proteins in the chick retinal tissue, but also demonstrated the dynamic protein expression changes during early ocular development. This represents one of the first steps in building a complete protein database in chick retinae which is applicable to the study of eye diseases from a few selected protein candidates to the whole proteome. Proteomic technology may provide a high throughput platform for advancing eye research in the feasible future.

Free perforator crossover TRAM flap for breast reconstruction

Breast reconstruction using a transverse rectus abdominis musculocutaneous (TRAM) flap has become the preferred method of autogenous reconstruction for most surgeons. The vascular basis of both the superior and inferior vascular pedicles of this flap has been well documented. When a pedicled TRAM flap is based superiorly, the perfusion across the midline to zone 4 and sometimes zone 3 is, at best, variable. Augmentation of the blood supply of the contralateral side with various methods has been reported. The methods include the delay procedure, bipedicled flaps, supercharging, and turbo-charging. The deep inferior epigastric artery is the dominant blood supply, and a microsurgical free TRAM flap based inferiorly provides reliable perfusion, even to zone 4, which obviates the need for many of these maneuvers. It has also been demonstrated that the circulation across the midline in a TRAM flap is primarily by means of a subdermal plexus and that with a previous vertical midline abdominal scar there is virtually no midline crossover at any anastomotic level. Therefore, even with a free TRAM flap based on the dominant inferior pedicle, perfusion across a vertical midline scar is unreliable. As a result, many patients with a vertical midline scar have been denied the best autogenous reconstructive option. The authors present their experience with a free perforator crossover TRAM flap using a constant premuscular branch of the deep inferior epigastric artery and vein that provides many patients who have a previous midline scar with a genuine option for autogenous tissue breast reconstruction.

Regeneration of nerve fibres across a colonic anastomosis in the guinea-pig

Resection and re-anastomosis of the bowel interrupts enteric neuronal pathways. The reestablishment of neuronal connections across a colonic anastomosis was studied using immunohistochemical, retrograde tracing and physiological techniques. In control guinea-pig proximal colon, retrograde labelling with 1,1'-didodecyl-3,3,3,3'-tetramethylindocarbocyanine perchlorate (DiI) revealed that enteric neurons with anally-directed projections are more numerous and have longer axons than orally-projecting neurons. In resected bowel, up to 26 weeks after re-anastomosis, descending neuronal pathways were substantially interrupted. Immunohistochemical labelling of nerve fibres revealed that some enteric nerve fibres did regenerate across narrow regions of the anastomosis, growing preferentially in the oral to anal direction. However, nerve fibres immunoreactive for neurofilament protein triplet were substantially depleted in myenteric ganglia anal to the anastomosis, even after the longest recovery periods, demonstrating that axonal regrowth was limited. This was confirmed in retrograde tracing studies, as no nerve cell bodies oral to an anastomosis were labelled when DiI was placed on myenteric ganglia just anal to the anastomosis. Physiological studies confirmed that regrowth of nerve fibres across the anastomosis occurred and that it was asymmetric, as electrical stimulation led to aboral conduction across the anastomosis more reliably than oral conduction, as measured by circular muscle contraction. After resection and re-anastomosis of the colon, the disruption of neuronal pathways in the enteric nervous system was observed, with limited and preferential re-establishment of aborally-directed long connections.

Variations in rupture site and surface strains at failure in the maturing rabbit medial collateral ligament

The relationship between the pattern of surface strain and the site of failure in maturing rabbit ligaments was studied in vitro. Bone-medial collateral ligament (MCL)-bone complexes of 24 female New Zealand White rabbits at 3, 6, 9 and 12 months of age (n = 6 rabbits, 12 MCLs per group) were tested in tension to failure. A video dimension analysis (VDA) system was used to map the surface strain at failure across the width and along the length of the medial side of each MCL during testing. Results showed that the highest strains were consistently located at the femoral insertion decreasing towards the midsubstance, with the highest strain occurring in the anterior portion of the MCL immediately adjacent to the femoral insertion. Strains of the complex at failure increased with rabbit maturation. The strain distribution however, did not change dramatically, even though the locations of MCL failure changed from exclusively tibial avulsion in the three month old rabbits to predominantly midsubstance failures in the 12 month old rabbits. In the six month old rabbits, there was a particular dissociation with all MCLs failing near the tibial insertion while femoral strains were apparently the highest. These results suggest two possibilities beyond that of some unknown artifacts of optical strain measurement. First, since failure sites rarely correlated with areas of maximum surface strain in this study, it seems possible that higher strains could exist deeper in the tissue, particularly at the bone-ligament interface of the tibial insertion in immature animals and somewhere within the midsubstance of the MCL in the adult. Secondly, it is possible that the ligament material may be heterogeneous.

A cure for xerostomia? Free jejunal patch graft in oral reconstruction

A case of oral carcinoma associated with extensive leukoplakia and severe xerostomia is presented. The advantage of using a free jejunal patch graft to restore large intra-oral mucosal defects and concurrently eradicate xerostomia is demonstrated. Further, it is recommended that a tracheostomy be used routinely in such cases to avoid postoperative aspiration of the graft secretions. Following healing the use of osseointegrated implants can complete oral rehabilitation without compromising the graft.

Does squatting reduce pelvic floor descent during defaecation?

Neurogenic faecal and urinary incontinence result from a stretch-induced injury to the pelvic nerves, from difficult childbirth or from chronic straining at stool. It has been suggested that the condition occurs less frequently in societies where the squatting position is used during defaecation, and that squatting may minimize pelvic floor descent. This is a prospective study which evaluates the position of the pelvic floor during defaecation straining in 52 patients. The position of the perineum was measured at rest and during maximal defaecation straining using a perineometer, with the patient in the left lateral, sitting and squatting positions. There was a significant difference in the position of the perineum at rest and on straining between the left lateral position and both the sitting and squatting positions. However, there was no significant difference at rest or on straining between the sitting and squatting positions. These results show that squatting does not reduce pelvic floor descent during defaecation straining, and imply that squatting would not help reverse stretch-induced pudendal nerve damage.

Changes in the cyclic and static relaxations of the rabbit medial collateral ligament complex during maturation

There is at present no information on how the viscoelastic properties of bone-ligament-bone complexes change during maturation. Changes in the static and the cyclic relaxation behaviours of rabbit bone-medial-collateral-ligament-bone complexes at 3, 6, 9 and 12 months of age are described. These ages cover maturation and initial ageing of this complex. The specimens were subject to 30 cycles of uniaxial tension between zero and 0.68 mm extension at 10 mm min-1. Immediately after the cyclic test, the specimens were held at a constant 0.68 mm extension for 1200 s. The results showed that in both the cyclic and the static tests, specimens from 3-month-old animals relaxed significantly more than specimens at 6, 9 or 12 months of age, whereas those 6, 9 and 12 months old were not significantly different from each other. When the results of the cyclic tests were compared to those of the static tests, cyclic relaxation was higher than static relaxation for each of the 6-, 9- and 12-month-old specimens. For specimens 3 months of age, the opposite was observed. An explanation is offered whereby the total relaxation is suggested to be comprised of two parts: a material relaxation and a water flux component. Differing contributions by each of the two components at particular ages can explain the observed results.

Calibration characteristics of a video dimension analyser (VDA) system

A comprehensive calibration and error analysis of a video dimension analyser (VDA) system was carried out to determine the effects of various parameters relevant to actual test conditions on the characteristics of the system. The parameters considered were: (1) varying distances or angles between the test specimen and the camera; (2) refractive effects of glass tank and physiologic solutions; and (3) dynamic response of the VDA system. The error analysis shows that, at low strain levels, the strain computed by the VDA is sensitive to camera placement and orientation as well as the media through which the object is observed. Very large errors can occur at small nominal strains, depending on the system parameters (e.g. 80% error at 1% nominal strain for one set of parameters). At higher strain levels, the sensitivity of the system is reduced, and the strain computed by the VDA system approaches the nominal strain (10% error at 10% nominal strain).

Anastomotic complications after esophagectomy for cancer. A comparison of neck and chest anastomoses

Leakage, tumor recurrence, and stricture formation at the anastomosis are serious problems after esophagectomy for cancer of the esophagus or cardia. Because the prevalence of these postoperative complications may be affected by whether an anastomosis is made in the neck or in the chest, a comparison was made between anastomoses made at these two sites. During a period of some 7 years, we studied prospectively 411 patients who underwent resection for cancer of the esophagus or cardia and, after immediate reconstruction, had an anastomosis made in the neck or chest. The anastomotic leak rate for the neck anastomosis group was 4.3% and for the chest anastomosis group, 3.7% (p = not significant). The difference between leak rates of anastomoses fashioned by hand-sewn (5.0%) or stapled (3.0%) techniques was also not significant. The median upper resection margins in the neck and chest anastomosis groups were 4.5 cm and 3.5 cm, respectively. The corresponding rates of anastomotic tumor recurrence were 6.1% and 8.1% (p = not significant). The prevalence of benign stricture formation was significantly higher in the chest anastomosis group (19.2%) than in the neck anastomosis group (9.0%) (p = 0.002). This difference was a reflection of a significantly increased prevalence of stricture formation when an anastomosis was made by the stapler technique than with the hand-sewn method, and whereas most of the anastomoses in the neck were hand sewn (90%) the majority of those in the chest were stapled (80%). There were thus no statistically significant differences between the sites in terms of anastomotic leak and tumor recurrence rates, and the higher stricture rate in the chest anastomosis group was the result of more stapled anastomoses.

Surgical management of anal incontinence

The complex nature of the continence mechanism is reflected in the difficulties experienced in the surgical management of patients with faecal incontinence. Apparent anatomical abnormalities may be identified but the functional outcome following surgery may be unsatisfactory. It is therefore important to improve both the selection of patients as well as the surgical procedures themselves. Selection of patients for appropriate treatment should be based on clinical findings as well as anorectal physiology tests. Most patients referred for assessment fall into one of six categories: incontinence with a normal sphincter; minor incontinence due to local anal conditions; direct sphincter injury; neurogenic ("idiopathic") incontinence; rectal prolapse; generalised neurological condition. Minor anal conditions causing incontinence must be carefully identified for appropriate treatment. A large amount of work has been done over the past ten years on the pathophysiology of major incontinence and new surgical procedures have been developed. A common difficulty is deciding whether anterior sphincter attenuation or neurogenic weakness is the dominant lesion causing incontinence; overlapping sphincter repair is indicated for the former and postanal repair for the latter. Anorectal physiology studies can be helpful in differentiating these conditions and are now used routinely in the assessment of patients.

Hypotension and endoscopic stigmata of recent haemorrhage in bleeding peptic ulcer: risk models for rebleeding and mortality

Clinical and endoscopic data were collected prospectively in 1050 patients with bleeding peptic ulcer admitted between September 1985 and July 1989 to the care of one surgical team. Seventy-nine patients underwent therapeutic endoscopy soon after admission and in 129 patients either immediate or early elective surgery was performed. Eight hundred and forty-two patients, in whom therapeutic endoscopy was not performed at any stage, underwent initial conservative management and data from this latter group are now presented. Shock on admission was defined as systolic blood pressure (BP) less than or equal to 100 mmHg on presentation. There were 10 deaths of 147 shocked patients (6.8%) compared with only 25 deaths of 695 patients (3.6%) not in shock (P less than 0.08). Bleeding recurred in 30 patients (20.4%) shocked on presentation but in only 96 (13.8%) with a BP greater than 100 mmHg (P less than 0.05). Twenty-one of 358 patients (5.9%) with endoscopic stigmata of recent haemorrhage (ESRH) died, but only 14 of 484 patients (2.9%) without such stigmata (P less than 0.05) died. In shocked patients rebleeding was evident in 21 of 73 (28.8%) cases with ESRH but in only 9 of 74 (12.2%) patients in whom ESRH were absent (P less than 0.02). In the absence of fresh blood at endoscopy rebleeding occurred in 22 of 124 (17.8%) shocked patients and only 74 of 629 (11.8%) of those not shocked on presentation (P less than 0.07). When ulcer size was documented rebleeding rates for ulcers less than or equal to 1 cm, less than or equal to 2 cm and greater than 2 cm in size were 54 of 485 (11.1%), 30 of 142 (21.2%) and 12 of 44 (27.3%) respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical procedures for uncomplicated ("routine") female stress incontinence

Routine incontinence in the woman is defined as stress urinary incontinence associated with a hypermobile urethra and bladder neck that has not been subjected to an operative procedure. Although urgency and occasional urgency incontinence may accompany the symptoms of stress incontinence, they are not a significant component of the patient's complaints. Regardless of technique, the goal common to all procedures designed to cure stress urinary incontinence is to immobilize and support the hypermobile urethra. The support provided by the operation creates a foundation on which the urethra can be compressed shut during abdominal straining. The operation of choice is determined by its ability to provide this strong foundation over a long period of time. Although numerous reports have been published outlining the results of bladder neck suspension, most authors have not utilized objective long-term follow-up when assessing cure rates. We prefer either the Burch colpourethropexy or the modified Pereyra needle bladder neck suspension because the vaginal wall is firmly supportive without interfering with the delicate mechanisms of the urethra.

The effects of temperature on the viscoelastic properties of the rabbit medial collateral ligament

There are disparate views on the effects of temperature on the mechanical properties of ligaments and tendons. We attempted to resolve the inconsistencies by testing the medial collateral ligaments of twelve, three-month old New Zealand white rabbits in both elastic-dominated and viscous-dominated tests between 25 degrees C and 55 degrees C. We found that in elastic-dominated monotonic loading, the loading portions of the load-extension curves were mathematically similar. Differences could be accounted for through a base-line shift of the origin caused by additional relaxation and thermal contraction/expansion of the apparatus and specimen. In tests where the viscous component of behavior was manifest, we found results similar to those of other investigators. Thus we conclude that in assessing the effects of temperature on the mechanical properties of tissues it is important to account for both temperature and initial positions of the apparatus and specimen, and to consider the effects of both relaxation and thermal contraction/expansion.

A new method of measuring the cross-sectional area of connective tissue structures

There appears to be no generally accepted method of measuring in-situ the cross-sectional area of connective tissues, particularly small ones, before mechanical testing. An instrument has therefore been devised to measure the cross-sectional area of one such tissue, the rabbit medial collateral ligament, directly and nondestructively. However, the methodology is general and could be applied to other tissues with appropriate changes in detail. The concept employed in the instrument is to measure the thickness of the tissue as a function of position along the width of the tissue. The plot obtained of thickness versus width position is integrated to provide the cross-sectional area. This area is accurate to within 5 percent, depending mainly on alignment of the instrument and pre-load of the ligament. Results on the mid-substance of the rabbit medial collateral ligaments are repeatable and reproducible. Values of maximum width and thickness are less variable than those obtained with a vernier caliper. The measured area is considerably less than that estimated assuming rectangular cross-section and slightly less than that estimated on the assumption of elliptical cross-section.

Influence of dietary lipid on the metabolism of hexobarbital by the isolated, perfused rat liver

Isolated livers from rats fed a diet containing corn oil (10% W/W) perfused with a blood-free, modified Krebs-Henseleit solution cleared hexobarbital at a rate significantly faster than livers from rats fed a similar diet devoid of corn oil. The half-lives of hexobarbital in these experiments were 22.4 +/- 1.8 min for livers from rats fed corn oil and 30.0 +/- 1.2 min for those from rats fed the fat-free diet. This represented a metabolic rate of 54 microgram hexobarbital/g liver/min in fat-fed animals and 36 microgram hexobarbital/g liver/min in those fed a rat-free diet.