[ANCA-negative granulomatosis with polyangiitis: a case report]

We reported a case of 73-year-old male with multiple pulmonary nodules and cavities. The patient was admitted with a chief complaint of "dry cough with shortness of breath for 3 months". Chest CT showed multiple irregular masses, nodules, and patchy lesions in both lungs, accompanied by the formation of cavities. He also had anemia and renal dysfunction. Despite given empirical anti-infective and anti-tuberculosis treatments, the pulmonary nodules progressed, and the cavities enlarged. Anti-neutrophil cytoplasmic antibodies (ANCA) were negative twice. Bronchoscopic biopsy was performed. The mucosal pathology of the right middle lobe lesion showed little necrosis, focal granulomatous structure formation, and relevant vasculitis and remaining vessel wall structure in the necrosis lesions by elastic fiber staining. A clinical diagnosis of ANCA-negative necrotizing granulomatous polyangiitis was made and the patient was treated with glucocorticoids and cyclophosphamide. The nodules and cavities shrank, and some lesions were absorbed.

The influence of the environment and lifestyle on myopia

BACKGROUND

Myopia, commonly known as near-sightedness, has emerged as a global epidemic, impacting almost one in three individuals across the world. The increasing prevalence of myopia during early childhood has heightened the risk of developing high myopia and related sight-threatening eye conditions in adulthood. This surge in myopia rates, occurring within a relatively stable genetic framework, underscores the profound influence of environmental and lifestyle factors on this condition. In this comprehensive narrative review, we shed light on both established and potential environmental and lifestyle contributors that affect the development and progression of myopia.

MAIN BODY

Epidemiological and interventional research has consistently revealed a compelling connection between increased outdoor time and a decreased risk of myopia in children. This protective effect may primarily be attributed to exposure to the characteristics of natural light (i.e., sunlight) and the release of retinal dopamine. Conversely, irrespective of outdoor time, excessive engagement in near work can further worsen the onset of myopia. While the exact mechanisms behind this exacerbation are not fully comprehended, it appears to involve shifts in relative peripheral refraction, the overstimulation of accommodation, or a complex interplay of these factors, leading to issues like retinal image defocus, blur, and chromatic aberration. Other potential factors like the spatial frequency of the visual environment, circadian rhythm, sleep, nutrition, smoking, socio-economic status, and education have debatable independent influences on myopia development.

CONCLUSION

The environment exerts a significant influence on the development and progression of myopia. Improving the modifiable key environmental predictors like time spent outdoors and engagement in near work can prevent or slow the progression of myopia. The intricate connections between lifestyle and environmental factors often obscure research findings, making it challenging to disentangle their individual effects. This complexity underscores the necessity for prospective studies that employ objective assessments, such as quantifying light exposure and near work, among others. These studies are crucial for gaining a more comprehensive understanding of how various environmental factors can be modified to prevent or slow the progression of myopia.

Axial length elongation profiles from 3 to 6 years in an Asian paediatric population: the Growing Up in Singapore Towards Healthy Outcomes birth cohort study (GUSTO)

AIMS

To determine axial length (AL) elongation profiles in children aged 3-6 years in an Asian population.

METHODS

Eligible subjects were recruited from the Growing Up in Singapore Towards Healthy Outcomes birth cohort. AL measurement was performed using IOLMaster (Carl Zeiss Meditec, Jena, Germany) at 3 and 6 years. Anthropometric measurements at birth, cycloplegic refraction at 3 and 6 years, questionnaires on the children's behavioural habits at 2 years and parental spherical equivalent refraction were performed. Multivariable linear regression model with generalised estimating equation was performed to determine factors associated with AL elongation.

RESULTS

273 eyes of 194 children were included. The mean AL increased from 21.72±0.59 mm at 3 years to 22.52±0.66 mm at 6 years (p<0.001). Myopic eyes at 6 years had greater AL elongation (1.02±0.34 mm) compared with emmetropic eyes (0.85±0.25 mm, p=0.008) and hyperopic eyes (0.74±0.16 mm, p<0.001). The 95th percentile limit of AL elongation was 1.59 mm in myopes, 1.34 mm in emmetropes and 1.00 mm in hyperopes. Greater birth weight (per 100 g, β=0.010, p=0.02) was significantly associated with greater AL elongation from 3 to 6 years, while parental and other behavioural factors assessed at 2 years were not (all p≥0.08).

CONCLUSION

In this preschool cohort, AL elongates at an average length of 0.80 mm from 3 to 6 years, with myopes demonstrating the greatest elongation. The differences in 95th percentile limits for AL elongation between myopes, emmetropes and hyperopes can be valuable information in identifying myopia development in preschool children.

Benchmarking large language models' performances for myopia care: a comparative analysis of ChatGPT-3.5, ChatGPT-4.0, and Google Bard

BACKGROUND

Large language models (LLMs) are garnering wide interest due to their human-like and contextually relevant responses. However, LLMs' accuracy across specific medical domains has yet been thoroughly evaluated. Myopia is a frequent topic which patients and parents commonly seek information online. Our study evaluated the performance of three LLMs namely ChatGPT-3.5, ChatGPT-4.0, and Google Bard, in delivering accurate responses to common myopia-related queries.

METHODS

We curated thirty-one commonly asked myopia care-related questions, which were categorised into six domains-pathogenesis, risk factors, clinical presentation, diagnosis, treatment and prevention, and prognosis. Each question was posed to the LLMs, and their responses were independently graded by three consultant-level paediatric ophthalmologists on a three-point accuracy scale (poor, borderline, good). A majority consensus approach was used to determine the final rating for each response. 'Good' rated responses were further evaluated for comprehensiveness on a five-point scale. Conversely, 'poor' rated responses were further prompted for self-correction and then re-evaluated for accuracy.

FINDINGS

ChatGPT-4.0 demonstrated superior accuracy, with 80.6% of responses rated as 'good', compared to 61.3% in ChatGPT-3.5 and 54.8% in Google Bard (Pearson's chi-squared test, all p ≤ 0.009). All three LLM-Chatbots showed high mean comprehensiveness scores (Google Bard: 4.35; ChatGPT-4.0: 4.23; ChatGPT-3.5: 4.11, out of a maximum score of 5). All LLM-Chatbots also demonstrated substantial self-correction capabilities: 66.7% (2 in 3) of ChatGPT-4.0's, 40% (2 in 5) of ChatGPT-3.5's, and 60% (3 in 5) of Google Bard's responses improved after self-correction. The LLM-Chatbots performed consistently across domains, except for 'treatment and prevention'. However, ChatGPT-4.0 still performed superiorly in this domain, receiving 70% 'good' ratings, compared to 40% in ChatGPT-3.5 and 45% in Google Bard (Pearson's chi-squared test, all p ≤ 0.001).

INTERPRETATION

Our findings underscore the potential of LLMs, particularly ChatGPT-4.0, for delivering accurate and comprehensive responses to myopia-related queries. Continuous strategies and evaluations to improve LLMs' accuracy remain crucial.

FUNDING

Dr Yih-Chung Tham was supported by the National Medical Research Council of Singapore (NMRC/MOH/HCSAINV21nov-0001).

Taxonomic and ecophysiological characteristics of actinobacteria in soils of the dry steppe zone of the Selenga Highlands (Western Transbaikalia)

Arid habitats have recently attracted increasing attention in terms of biodiversity research and the discovery of new bacterial species. These habitats are among the target ecosystems suitable for isolating new strains of actinobacteria that are likely to produce new metabolites. This paper presents the results on the isolation of actinobacteria from soils of the dry steppe zone of the Selenga Highlands, the characterization of their taxonomic diversity, as well as ecological and trophic properties. The bacterial counts on ISP 4 medium ranged from 6.6 × 105 to 7.1 × 106 CFU/g. The highest bacterial counts were observed in the subsurface and middle horizons of the studied soils. 28 strains of Gram-positive bacteria represented by thin-branched mycelium, coccoid and bacilliform forms were isolated. According to the results of 16S rRNA gene analysis, the isolated strains were representatives of Streptomyces, Arthrobacter, Glycomyces, Kocuria, Microbacterium, Micromonospora, Nocardioides, Pseudarthrobacter, and Rhodococcus (Actinomycetota). One isolate that showed low 16S rRNA gene sequence similarity with previously isolated and validly described species was a new species of the genus Glycomyces. It was shown that all tested strains are mesophilic, prefer neutral or slightly alkaline conditions, have growth limits in the temperature range of 5-45 °C and pH 6-9. The optimal NaCl concentration for growth of most strains was 0-1 %. The strains under study were capable of utilizing a wide range of mono- and disaccharides and polyatomic alcohols as a carbon source. The isolated strains were capable of using both organic (proteins and amino acids) and inorganic (ammonium salts and nitrates) compounds as nitrogen sources. The examinations of extracellular enzymes showed that all isolates were capable of producing catalase and amylase; 78.6 % of the total number of isolates produced protease and lipase; 53.6 %, cellulase; and 28.6 %, urease. The data obtained expand current knowledge about the diversity of microbial communities in soils of the Selenga Highlands and also confirm the potential of searching for new actinobacteria species in these soils.

Association of time outdoors and patterns of light exposure with myopia in children

BACKGROUND/AIMS

To evaluate the association of reported time outdoors and light exposure patterns with myopia among children aged 9 years from the Growing Up in Singapore Towards Healthy Outcomes birth cohort.

METHODS

We assessed reported time outdoors (min/day), light exposure patterns and outdoor activities of children aged 9 years (n=483) with a questionnaire, the FitSight watch and a 7-day activity diary. Light levels, the duration, timing and frequency of light exposure were assessed. Cycloplegic spherical equivalent (SE), myopia (SE≤-0.5 D) and axial length (AL) of paired eyes were analysed using generalised estimating equations.

RESULTS

In this study, 483 (966 eyes) multiethnic children (50.0% boys, 59.8% Chinese, 42.2% myopic) were included. Reported time outdoors (mean±SD) was 100±93 min/day, and average light levels were 458±228 lux. Of the total duration children spent at light levels of ≥1000 lux (37±19 min/day), 76% were spent below 5000 lux. Peak light exposure occurred at mid-day. Children had 1.7±1.0 light exposure episodes/day. Common outdoor activities were walks, neighbourhood play and swimming. Greater reported time outdoors was associated with lower odds of myopia (OR=0.82, 95% CI 0.70 to 0.95/hour increase daily; p=0.009). Light levels, timing and frequency of light exposures were not associated with myopia, SE or AL (p>0.05).

CONCLUSION

Reported time outdoors, light levels and number of light exposure episodes were low among Singaporean children aged 9 years. Reported time outdoors was protective against myopia but not light levels or specific light measures. A multipronged approach to increase time outdoors is recommended in the combat against the myopia epidemic.

Sleep Patterns and Myopia Among School-Aged Children in Singapore

Purpose

To evaluate the associations of sleep factors with myopia, spherical equivalent (SE), and axial length (AL) in elementary school-aged children from the Growing Up in Singapore Towards healthy Outcomes (GUSTO) birth cohort.

Methods

This cross-sectional study included multi-ethnic children who participated in the GUSTO prospective birth cohort and were delivered in two major tertiary hospitals in Singapore (2009–2010). Sleep factors and myopia outcomes were assessed at the 8- and 9-year study visits, respectively. Parent-reported sleep quality was assessed with the Children's Sleep Habits Questionnaire (CSHQ) total scores. Additionally, each child's sleep duration, timing (bedtime; waketime), and the consistency of sleep duration or timing (i.e., the difference between weekends and weekdays) were parent-reported. Outcomes included cycloplegic SE, myopia (SE ≤ −0.5 D) and AL. Eye measurements from both eyes were included in the analyses. Multivariable linear or logistic regression with Generalized Estimating Equations were used to account for the correlation between paired eyes and confounders in the associations of sleep factors at age 8 and myopia at age 9.

Results

A total of 572 multi-ethnic children (49.5% boys; 56.1% Chinese) aged 9 years were included in the analyses. Overall, 37.3% of eyes were myopic. Children reported a mean total CSHQ score of 46 [standard deviation (SD) = 6]. The mean duration of sleep was 9.2 (SD = 1.0) hours per day (h/day), with 59.9% of children reporting sufficient sleep (≥9 h/day) based on guidelines recommended by the National Sleep Foundation, USA. The mean bedtime and wake time were 22:00 (SD = 00:53) and 07:08 (SD = 00:55), respectively. In multivariable regression models, total CSHQ scores, the duration of sleep, bedtime and wake time were not significantly associated with myopia, SE, or AL (p ≥ 0.05 for all), adjusting for gender, ethnicity, time outdoors, near-work, parental myopia, maternal education levels (and additionally the child's height when the outcome was AL). Similarly, the consistency of both the duration and timing of sleep (across weekends and weekdays) were not significantly associated with myopia, SE, or AL (p ≥ 0.05 for all).

Conclusion

In this cross-sectional study, sleep quality, duration, timing, and the consistency of specific sleep factors were not independently associated with myopia, SE, or AL among elementary school-aged children in Singapore. Large longitudinal studies are warranted to corroborate these results.

[Efficacy analysis of selective genicular artery embolization in the treatment of knee pain secondary to osteoarthritis]

Objective: To evaluate the efficacy and safety of selective genicular artery embolization for the treatment of the knee pain secondary to osteoarthritis. Methods: From October 2020 to July 2021, 17 patients (23 knees) aged (68±7) years with moderate to severe knee pain secondary to knee osteoarthritis were prospectively included in the General Hospital of Ningxia Medical University. There were 6 males and 11 females included in this research. Patients were assessed with knee pain, stiffness, and function with the Visual Analogue Scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at baseline, using the Kellgren-Lawrence (K-L) grading to evaluate the severity of KOA, and using the Magnetic Resonance Knee Osteoarthritis Score (MOAKS) to evaluate the MR imaging characteristics of the affected knee. Selective genicular artery embolization (GAE) was performed in all patients. The patients were followed up for 6 months after the procedure. Patients were assessed with the VAS score and WOMAC scale at 1 d, 1 week and 1, 3 and 6 months after the procedure to evaluate the clinical outcomes, including the improvement of knee joint pain, stiffness and function, as well as the occurrence of adverse reactions. Results: Three to seven genicular artery branches were superselected and embolized in 23 knees, and 4 to 7 genicular artery branches were embolized in 7 patients with K-L grade 4. The clinical improvement was 95.6% (22/23) at 1 month, 86.9% (20/23) at 3 months, and 91.3% (21/23) at 6 months. Twenty-three knees completed the 6-month follow-up, and the VAS score, WOMAC pain score, and total WOMAC score at 1, 3, and 6 months after surgery were (2.5±1.3), (3.4±2.4), and (19.7±9.8) points, (3.0±1.8), (4.5±3.4), and (22.3±11.3) points, (2.8±1.5), (4.1±3.0), and (20.5±11.0) points, which were lower than the (6.6±0.9), (11.4±2.6) and (47.0±12.0) points at baseline (all P<0.001). During the follow-up period, 7 patients had adverse reactions: 3 cases had skin ecchymosis in the femoral artery puncture area, 4 cases had knee joint stiffness and pain within 1 day after operation, which were relieved spontaneously in 1 week, 6 patients had joint clicking during extension and flexion activities after operation, of which 3 cases subsided spontaneously within 3 months after operation. None of the patients had major procedure-related adverse events. Conclusion: GAE has a high clinical improvement rate and a low incidence of adverse reactions in the treatment of the pain secondary to knee osteoarthritis, which provides a new treatment option for patients who fail to respond to conservative treatment.

Dietary intake and associations with myopia in Singapore children

PURPOSE

To evaluate associations of dietary factors with myopia, spherical equivalent refractive error (SE) and axial length (AL) in children at age 9 from the Growing Up in Singapore Towards healthy Outcomes (GUSTO) birth cohort.

METHODS

We included 467 multi-ethnic children (933 eyes) who participated in the GUSTO prospective birth cohort and were delivered in two major hospitals in Singapore (2009-2010). At the 9-year visit, we assessed the 6-year incidence of myopia (between ages 3 to 9), cycloplegic SE and AL in children without myopia (SE ≤ -0.5 D in either eye) at the 3-year visit. Using a validated 112-item food frequency questionnaire, parents reported each child's average daily intake of dietary factors (nutrients and food groups) in the past month. Paired eyes were analysed using Generalised Estimating Equations with multivariable logistic or linear regression. Bonferroni corrections were applied, correcting for multiple comparisons between the 13 nutrients (p < 0.004) or 8 food groups (p < 0.006) and each outcome.

RESULTS

In children aged 9 years (51.0% boys; 56.3% Chinese), the 6-year incidence of myopia was 35.5%. Overall, the mean (SD) SE and AL were -0.3 (1.7) D and 23.4 (1.0) mm, respectively. In multivariable regression, macronutrients or micronutrients were not associated with incident myopia (p ≥ 0.004 for all), adjusting for total energy, gender, ethnicity, time outdoors, near-work and the number of myopic parents (additionally child's height for outcome AL). Similarly, all food groups (including refined grains, sugar-sweetened beverages, protein foods, fruits and vegetables) were not associated with incident myopia (p ≥ 0.006 for all). Additionally, none of the nutrients (p ≥ 0.004 for all) or food groups (p ≥ 0.006 for all) were associated with SE or AL.

CONCLUSIONS

Our study findings of no significant association between specific nutrients or food groups and incident myopia or SE or AL suggest that diet may not be associated with myopia in children aged 9 years. Well-conducted prospective studies in other populations may clarify the association.

[Several considerations on the establishment of a new public health and preventive medicine system in national level]

Based on the new mission of public health set in the Healthy China strategy and the insufficient response to COVID-19, this article pointed out the problems of the current public health and preventive medicine system from the macro-system level, meso-organization level, and micro-individual level, including insufficient strategic planning, resource input, institutional coordination, talent training and team building. It was creatively proposed that a disease prevention and control bureau should be set up outside the health commission to implement the vertical management at four levels, from national level to province-level, including autonomous region, municipality directly under the central government, city-level and district/county-level. The disease prevention and control bureau should consist of a strategic research institute, a center for disease prevention and control (CDC), a human resources training base, and a scientific research institute, which could perform their own duties and rely on each other. Enhancing the functions of strategic planning, overall coordination, and evidence-based decision-making in the original system, emphasizing the foresight and continuity of scientific research, and allowing the CDC to focus more on health management and emergency response could better facilitate in protecting the public health, improving the health and quality of life of the entire population, and guaranteeing the social stability and development.

[Crouzon syndrome with secretory otitis media: a case report and literature review]

Summary Clinical data from a case of Crouzon syndrome with secretory otitis media in our department was collected and the related literatures were reviewed. Whole exome sequecing and Sanger sequencing were performed to analyze genetic cause. The 6-year old patient with Crouzon syndrome had snoring and mouth breathing during sleep for 2 years, and was found hearing loss for 2 weeks. The results of endoscopy showed adenoid hypertrophy and secretory otitis media of both ears. And CT scan proved chronic rhinosinusitis. Myringotomy and adenoidectomy were done under general anesthesia. The follow-up at 6 months showed normal sleep and hearing level. A heterozygous fibroblast growth factor receptor 2 missense mutation（c.1061C>G, p.S354C） in exon 8 was identified in this patient.

High quality nursing of children with pneumonia complicated with heart failure

Children with severe pneumonia often have heart failure. This study explored the clinical effect of high quality nursing intervention on children with pneumonia complicated with heart failure. In the study, 96 children with pneumonia complicated with heart failure were selected and randomly divided into a conventional nursing group (n=48) and a high quality nursing group (n=48). Based on the conventional nursing, the children in one group were given high quality nursing, and comprehensive nursing was carried out in aspects such as respiratory tract, medication, psychology and diet. Then, the heart rate, respiratory rate, heart failure correction time, hospitalization time, cost and nursing satisfaction were compared between the two groups. The results showed that the heart rate of the high quality nursing group was 145.37±8.72 times/min and the respiratory rate was 45.65±6.08 times/min, which were significantly lower than those of the conventional nursing group (P less than 0.05). The correction time of heart failure was about 32 h in the high quality nursing group, and the length and cost of hospitalization were significantly lower than those in the conventional nursing group (P less than 0.05). The nursing satisfaction of the patients' family members in the high quality nursing group was also higher (P less than 0.05). This study shows that high quality nursing can promote the recovery of children with pneumonia complicated with heart failure, and is worth popularizing widely in clinics.

[Sleep problems and the association with the levels of 6-sulfatoxymelatonin in children with autism spectrum disorder]

Objective: To identify the prevalence of sleep problems in children with autism spectrum disorder (ASD) and to explore the association with the main melatonin metabolite, 6-sulfatoxymelatonin (6-SM). Method: This was a prospective case-control study. Children with ASD were recruited from Child Development and Behavioral Research Center (CDBRC) of the Harbin Medical University and Harbin Special Education School from October 2015 to April 2017 (ASD group) . Healthy controls were selected from five kindergartens and one primary school in Harbin by the stratified cluster random sampling (control group) . The Children's Sleep Habits Questionnaire (CSHQ) was used to investigate the sleep problems of the two groups. The patients were matched in a 1∶1 ratio for the age and sex, and the urine samples of case-control pairs were collected in the morning. The level of 6-SM was measured by the enzyme linked immunosorbent assay (ELISA). The student's t test was used for comparison between the ASD group and control group, and the Pearson correlation analysis was used to determine the correlation difference. Result: A total of 212 ASD children (mean (±SD) age was (6.0±2.7) years, and 181 patients (85.4%) were male), and a total of 334 healthy children(mean (±SD) age was (5.9±2.6) years, and 272 patients (81.4%) were male) were recruited. Among them, 101 matched case-control pairs completed the collection of urine samples. According to the statistical analysis, the scores of total CSHQ, bedtime resistance, sleep onset delay, sleep duration, night waking, parasomnia, sleep disordered breathing and daytime sleepiness in children with ASD were significantly higher than those in the control group (48.2±6.2 vs. 46.6±5.4, 11.4±2.5 vs. 10.7±2.8, 1.7±0.8 vs. 1.5±0.7, 4.1±1.4 vs. 3.7±1.1, 4.2±1.5 vs. 3.8±1.1, 8.5±1.5 vs. 8.3±1.4, 3.7±1.0 vs. 3.4±0.8, 11.7±2.5 vs. 12.4±2.7, t=3.16, 3.00, 3.23, 2.76, 3.19, 1.99, 3.45,-2.72, P=0.002, 0.003, 0.001, 0.006, 0.002, 0.048, 0.001, 0.007), the level of 6-SM was significantly lower in children with ASD than that of healthy controls ((1.24±0.50) vs. (1.68±0.63)μg/h, t=-5.50, P<0.01), and the total CSHQ score was negatively correlated with the level of 6-SM (r=-0.50, P<0.01). Conclusion: The children with ASD were at high risk for sleep problems, and the melatonin metabolite of ASD group was abnormal compared with that of the control group. Moreover, there was a negative correlation between the severity of sleep problems and the level of 6-SM in ASD children. The results of our study indicate that the abnormal melatonin metabolism may be one of the causes of sleep problems in children with ASD.

[The relationship between gut microbiota and diet and nutrition related diseases]

The human gastro-intestinal tract is not only the habitat of gut microbiota, but also the main place that the body gets available nutrients. Therefore, the gut microbiota of human can be inseparable associated with the human nutrition. The common technologies used among gut microbiota research included metageonomic, metatranscriptomics, metaproteomics, and metabolomics. The research of gut microbiota based on above omics methods confirmed that diets were the main factors influencing the composition and expression of gut microbiota. The proportion, quantity, stable state, and metabolic changes of gut microbiota were closely related to obesity, diabetes mellitus, cardiovascular disease, and other nutritional-related diseases. Reasonable dietary intervention can adjust the disorders of gut microbiota, which can achieve prevention and treatment of obesity, diabetes, cardiovascular diseases, and other nutritional-related diseases. Although the single omics methods can be used to study the problems of some aspects of gut microbiota, the combination of multi-omics is needed to achieve the above objectives.

Optical Coherence Tomography in Patients With the Subretinal Implant Retina Implant Alpha IMS

BACKGROUND AND OBJECTIVE

The aim of this study was to assess changes in retinal structure and thickness after subretinal implantation of the Retina Implant Alpha IMS (Retina Implant AG, Reutlingen, Germany).

PATIENTS AND METHODS

Spectral-domain optical coherence tomography (SD-OCT) imaging was performed to assess the structure and thickness of the retina anterior to the microphotodiode array preoperatively, within 6 weeks and 6 months ± 1 month after implantation. Thickness measurements were performed using the distance tool of the built-in software. Three thickness measurements were performed in each of the four quadrants of the retina on the microchip within 6 weeks and 6 months ± 1 month after implantation.

RESULTS

The mean ± standard deviation change in retinal thickness from within 6 weeks to 6 months ± 1 month after implantation in all four quadrants combined was 24 μm ± 68 μm. None of the tested variables (location, time, or their interaction) had a statistically significant effect on the mean retinal thickness (P = .961, P = .131, and P = .182, respectively; n = 19).

CONCLUSION

The authors report on qualitative and quantitative findings in retinal structure in 27 patients after subretinal implantation of the Retina Implant Alpha IMS using OCT technology. No significant changes of retinal thickness could be observed in a period of 6 months after surgery. With more patients receiving subretinal implants and with advanced OCT technology, the data set will be extended to study possible changes in retinal structure in finer detail. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:993-999.].

Automated head motion system improves reliability and lessens operator dependence for head impulse testing of vestibular reflexes

Deficiency of the eye-stabilizing vestibulo-ocular reflex (VOR) is a defining feature in multiple diseases of the vestibular labyrinth, which comprises the inner ear's sensors of head rotation, translation and orientation. Diagnosis of these disorders is facilitated by observation and measurement of eye movements during and after head motion. The video head impulse test has recently garnered interest as a clinical diagnostic assessment of vestibular dysfunction. In typical practice, it involves use of video-oculography goggles to measure eye movements while a clinician examiner grasps the subject's head and manually rotates it left or right at sufficient acceleration to cover ~20 deg over ~150 mS, reaching a peak velocity of >120 deg/S midway through the movement. Manual delivery of head impulses incurs significant trial-by-trial, inter-session and inter-operator variability, which lessens the test's reliability, efficiency, safety and standardization across testing facilities. We describe application of a novel, compact and portable automated head impulse test (aHIT™) device that delivers highly repeatable head motion stimuli about axes parallel to those of the vestibular labyrinth's six semicircular canals, with programmable Gaussian and sinusoidal motion profiles at amplitudes, velocities and accelerations sufficient to test VOR function over the spectral range for which the VOR dominates other vision-stabilizing reflexes. We tested the aHIT™ on human subjects and demonstrated its high reproducibility compared to manually delivered head impulses. This device has the potential to be a valuable clinical and research tool for diagnostic evaluation and investigation of the vestibular system.

Determinants of optical coherence tomography-derived minimum neuroretinal rim width in a normal Chinese population

PURPOSE

To characterize an optical coherence tomography (OCT)-derived parameter, Bruch's membrane opening-minimum rim width (BMO-MRW), and its association with demographic and clinical parameters in normal Chinese subjects.

METHODS

Right eyes of 466 consecutive healthy subjects from a population-based study of Singaporean Chinese underwent Cirrus OCT imaging. The retinal internal limiting membrane (ILM) and BMO were automatically delineated using the built-in Cirrus algorithm. The standard 36 interpolated radial B-scans (72 BMO points, 5° increments) of each optic nerve head were manually extracted from the central circle (3.46-mm diameter). We used Matlab to measure the shortest distance from the BMO points to the ILM. Associations of BMO-MRW with demographic and clinical parameters were evaluated using marginal general estimating equations analysis.

RESULTS

There was a slight preponderance of male subjects (50.9%), with a mean age of 54.8 ± 7.63 years. Mean BMO-MRW was 304.67 ± 58.96 μm (range, 173.32-529.23 μm), which was highly associated with OCT-derived disc area (DA) (β = -91.78, P < 0.001) and rim area (RA) (β = 194.31, P < 0.001), followed by spherical refractive error (SRE) (β = -2.23, P = 0.02) and retinal nerve fiber layer (RNFL) thickness (β = 0.5, P = 0.04), after adjusting for the associated factors such as age, sex, intraocular pressure (IOP), and vertical cup-disc ratio (VCDR).

CONCLUSIONS

Disc area and RA had the strongest association with BMO-MRW, followed by SRE and RNFL thickness. The availability of this normative database will facilitate optic nerve head assessment using the BMO-MRW parameter in Chinese subjects.

Abstract W MP3: Endovascular Therapy in Large Vessel Occlusion Strokes with ASPECTS of 5-7 May Result in Reduced Infarct Volumes and Better Functional Outcomes

Introduction: Intra-arterial therapy (IAT) for large vessel occlusions strokes (LVOS) has been increasingly utilized. The benefit of endovascular reperfusion in patients with mid-range ASPECTS remains to be established.

Materials and methods: Retrospective analysis of LVOS patients with ASPECTS 5-7 treated with IAT (n=86) or medical therapy alone (±IV t-PA; n=15) at two academic centers from 2009-2012. Definitions employed: Symptomatic ICH: any parenchymal hematoma; Successful reperfusion: modified TICI≥2B; Good and acceptable clinical outcomes: 90-day mRS 0-2 and 0-3, respectively. Final infarct volumes were calculated based on 24-hour post-procedure CT or MRI scans.

Results: Mean age (67±14 vs. 67±19 years) and baseline NIHSS (20±5 vs. 20±6) were similar in the IAT and medical treatment groups. Successful reperfusion was achieved in 58 (67%) IAT patients. Symptomatic and asymptomatic ICH occurred in 9 (10%) and 31 (36%) IAT patients, respectively. The IAT rates of 90-day good and acceptable outcomes were 20% (17/86) and 33% (28/86), respectively. Successful reperfusion in IAT patients was associated with smaller FIV (p=0.015) and higher rates of good (p=0.02) and acceptable (p=0.03) outcomes. The median final infarct volume was significant lower with IAT vs. medical therapy (80ml [IQR, 38-122] vs. 190ml [121-267], p=0.015). There was a strong trend towards a higher hemicraniectomy requirement in medically vs. endovascularly treated patients (20% versus 6%, p=0.06) despite similar in-hospital mortality (20% versus 26.7 %, p=0.75).

Conclusions: Despite a low probability of achieving functional independence, IAT in LVOS patients with ASPECTS 5-7 appears to result in smaller final infarct volumes leading to a reduction in the need for hemicraniectomy and decreasing the degree of overall disability. Therefore, it may be a reasonable option for patients and families who favor a shift from severe to moderate disability. Prospective studies utilizing shift in outcome measures are warranted to confirm these results.

Feasibility of the assessment of cholesterol crystals in human macrophages using micro optical coherence tomography

The presence of cholesterol crystals is a hallmark of atherosclerosis, but until recently, such crystals have been considered to be passive components of necrotic plaque cores. Recent studies have demonstrated that phagocytosis of cholesterol crystals by macrophages may actively precipitate plaque progression via an inflammatory pathway, emphasizing the need for methods to study the interaction between macrophages and crystalline cholesterol. In this study, we demonstrate the feasibility of detecting cholesterol in macrophages in situ using Micro-Optical Coherence Tomography (µOCT), an imaging modality we have recently developed with 1-µm resolution. Macrophages containing cholesterol crystals frequently demonstrated highly scattering constituents in their cytoplasm on µOCT imaging, and µOCT was able to evaluate cholesterol crystals in cultured macrophage cells. Our results suggest that µOCT may be useful for the detection and characterization of inflammatory activity associated with cholesterol crystals in the coronary artery.

12S-hydroxyeicosatetraenoic acid levels link to coronary artery disease in Type 2 diabetic patients

BACKGROUND

12(S)-Hydroxyeicosatetraenoic acid (12(S)-HETE) is a metabolite of arachidonic acid. 12(S)-HETE is involved in the pathogenesis of atherosclerosis and diabetes. However, the correlation between 12(S)-HETE and coronary artery disease (CAD) in the diabetic patient is unclear.

AIMS

The study investigated the relationship between 12(S)-HETE and CAD in Type 2 diabetes (T2D).

METHODS

Plasma 12(S)- HETE levels were detected by enzyme-linked immunosorbent assay in 103 healthy controls (control), 109 diabetic patients without CAD (diabetic), and 152 diabetic patients with CAD (diabetic-CAD).

RESULTS

12(S)-HETE levels were higher in both diabetic and diabetic-CAD groups compared to control and in the diabetic-CAD group compared to the diabetic group. In the multiple linear stepwise regression analysis, 12(S)-HETE levels correlated independently with CAD, systolic blood pressure, and glycated hemoglobin.

CONCLUSIONS

These results indicate that 12(S)-HETE levels are increased in diabetic patients with CAD, suggesting a role for atherosclerosis in T2D.

Histidine supplementation improves insulin resistance through suppressed inflammation in obese women with the metabolic syndrome: a randomised controlled trial

AIMS/HYPOTHESIS

Increased inflammation and oxidative stress are associated with insulin resistance (IR) and metabolic disorders. Serum histidine levels are lower and are negatively associated with inflammation and oxidative stress in obese women. The objective of this study was to evaluate the efficacy of histidine supplementation on IR, inflammation, oxidative stress and metabolic disorders in obese women with the metabolic syndrome (MetS).

METHODS

A total of 100 obese women aged 33-51 years with BMI ≥ 28 kg/m² and diagnosed with MetS were included following a health examination in the community hospital in this randomised, double-blinded, placebo-controlled trial. Participants were allocated to interventions by an investigator using sequentially numbered sealed envelopes and received 4 g/day histidine (n = 50) or identical placebo (n = 50) for 12 weeks. Participants then attended the same clinic every 2 weeks for scheduled interviews and to count tablets returned. Serum histidine, HOMA-IR, BMI, waist circumference, fat mass, serum NEFA, and variables connected to inflammation and oxidative stress were measured at baseline and 12 weeks. Participants, examining physicians and investigators assessing the outcomes were blinded to group assignment. In addition, the inflammatory mechanisms of histidine were also explored in adipocytes.

RESULTS

At 12 weeks, a total of 92 participants completed this trail. Compared with the placebo group (n = 47), histidine supplementation significantly decreased HOMA-IR (-1.09 [95% CI -1.49, -0.68]), BMI (-0.86 kg/m² [95% CI -1.55, -0.17]), waist circumference (-2.86 cm [95% CI -3.86, -1.86]), fat mass (-2.71 kg [95% CI -3.69, -1.73]), serum NEFA (-173.26 μmol/l [95% CI -208.57, -137.94]), serum inflammatory cytokines (TNF-α, -3.96 pg/ml [95% CI -5.29, -2.62]; IL-6, -2.15 pg/ml [95% CI -2.52, -1.78]), oxidative stress (superoxide dismutase, 17.84 U/ml [95% CI 15.03, 20.65]; glutathione peroxidase, 13.71 nmol/ml [95% CI 9.65, 17.78]) and increased serum histidine and adiponectin by 18.23 μmol/l [95% CI 11.74, 24.71] and 2.02 ng/ml [95% CI 0.60, 3.44] in histidine supplementation group (n = 45), respectively. There were significant correlations between changes in serum histidine and changes of IR and its risk factors. No side effects were observed during the intervention. In vitro study indicated that histidine suppresses IL6 and TNF mRNA expression and nuclear factor kappa-B (NF-κB) protein production in palmitic acid-induced adipocytes in a dose-dependent manner, and these changes were diminished by an inhibitor of NF-κB.

CONCLUSIONS/INTERPRETATION

Histidine supplementation could improve IR, reduce BMI, fat mass and NEFA and suppress inflammation and oxidative stress in obese women with MetS; histidine could improve IR through suppressed pro-inflammatory cytokine expression, possibly by the NF-κB pathway, in adipocytes.

The effect of Fe doping on adsorption of CO2/N2 within carbon nanotubes: a density functional theory study with dispersion corrections

An ab initio density functional theory (DFT) study with correction for dispersive interactions was performed to study the adsorption of N(2) and CO(2) inside an (8, 8) single-walled carbon nanotube. We find that the approach of combining DFT and van der Waals correction is very effective for describing the long-range interaction between N(2)/CO(2) and the carbon nanotube (CNT). Surprisingly, exohedral doping of an Fe atom onto the CNT surface will only affect the adsorption energy of the quadrupolar CO(2) molecule inside the CNT (20-30%), and not that of molecular N(2). Our results suggest the feasibility of enhancement of CO(2)/N(2) separation in CNT-based membranes by using exohedral doping of metal atoms.

First principle study of hydrogenation of MgB2: an important step toward reversible hydrogen storage in the coupled LiBH4/MgH2 system

Recent experiments [F. E. Pinkerton, M. S. Meyer, G. P. Meisner, M. P. Balogh, and J. J. Vajo, J. Phys. Chem. C 111, 12881 (2007) and J. J. Vajo and G. L. Olson, Scripta Mater. 56, 829 (2007)] demonstrated that the recycling of hydrogen in the coupled LiBH4/MgH2 system is fully reversible. The rehydrogenation of MgB2 is an important step toward the reversibility. By using ab initio density functional theory calculations, we found that the activation barrier for the dissociation of H2 are 0.49 and 0.58 eV for the B and Mg-terminated MgB2(0001) surface, respectively. This implies that the dissociation kinetics of H2 on a MgB2(0001) surface should be greatly improved compared to that in pure Mg materials. Additionally, the diffusion of dissociated H atom on the Mg-terminated MgB2(0001) surface is almost barrier-less. Our results shed light on the experimentally-observed reversibility and improved kinetics for the coupled LiBH4/MgH2 system.

Stability of Supershort Single-Walled Carbon Nanotubes

How short can single-walled carbon nanotubes (SWNTs) be? How stable are such supershort SWNTs (ss-SWNTs)? This work is the first to address these questions. On the basis of binding energy (E(B)), standard heats of formation , and strain energy (E(S)), we found that SWNTs with only one benzene ring in the axial direction, which we refer to as supershort SWNTs (ss-SWNTs), can be thermodynamically stable. On the basis of the data of E(B), , and E(S), the relative stabilities of ss-SWNTs, fullerenes, polycyclic aromatic hydrocarbons, and butadiyne are discussed. This study has laid a theoretical foundation for the possible synthesis of ss-SWNTs.

Development of a novel indwelling balloon applicator for optimizing light delivery in photodynamic therapy

BACKGROUND AND OBJECTIVE

A human glioma spheroid model is used to investigate the efficacy of different light delivery schemes in 5-aminolevulinic acid (ALA)--mediated photodynamic therapy (PDT). The results provide the rationale for the development of an indwelling balloon applicator for optimizing light delivery.

STUDY DESIGN/MATERIALS AND METHODS

Human glioma spheroids were incubated in ALA (100 or 1000 microg /ml-1) for 4 hours and subjected to various light irradiation schemes. In one set of experiments, spheroid survival was monitored as a function of light fluence rate (5-200 mW cm-2). In all cases, spheroids were exposed to fluences of either 25 or 50 J cm-2. In a second study, the effects of repeated weekly PDT treatments, using sub-threshold fluences, were investigated. One group of spheroids was subjected to three treatments using fluences of 12, 12, and 25 J cm-2. Results were compared to spheroids receiving single treatments of either 12 or 25 J cm-2. A fluence rate of 25 mW cm-2 was used for all three groups of spheroids. In all cases, the effect of a given irradiation scheme was evaluated by monitoring spheroid growth.

RESULTS

Low fluence rates produce greater cell kill than high fluence rates. The minimum effective fluence rate in human glioma spheroids is approximately 10 mW cm-2. Repeated weekly PDT treatments with sub-threshold fluences result in significant cell kill. In spheroids surviving the PDT treatments, growth is suppressed for the duration of the treatment period.

CONCLUSION

The results of the in vitro studies support the development of an indwelling balloon applicator for the delivery of light doses in long term multi-fractionated PDT regimens.

[Bioequivalence of bambuteral and its metabolites terbutaline after oral bambuteral tablet in healthy volunteers by HPLC/MS]

AIM

To study bioequivalence of bambuteral and its metablites terbutaline in 20 healthy male volunteers.

METHODS

A single oral dose of domestic or imported bambuteral tablet was given according to a randomized 2-way cross-over design. The plasma bambuteral and terbutaline concentrations were determined by HPLC/MS.

RESULTS

The pharmacokinetic parameters of domestic and imported bambuteral: AUC0-t were (52 +/- 21) microgram.h.L-1 and (51 +/- 20) microgram.h.L-1, Tmax were (2.9 +/- 0.9) h and (2.6 +/- 0.7) h, Cmax were (6.0 +/- 2.6) microgram.L-1 and (6.2 +/- 2.9) microgram.L-1, T1/2Ke were (11.2 +/- 2.3) h and (11.2 +/- 1.9) h, respectively; terbutaline: AUC0-t were (191 +/- 30) microgram.h.L-1 and (197 +/- 37) microgram.h.L-1; Tmax were (4.2 +/- 1.0) h and (4.2 +/- 1.0) h; Cmax were (10 +/- 5) microgram.L-1 and (10 +/- 4) microgram.L-1; T1/2Ke were (20 +/- 3) h and (21 +/- 4) h, respectively. The bioavaiability of the domestics was 102% +/- 8% (bambuteral) and 100% +/- 12% (terbutaline).

CONCLUSION

The results demonstrate that the two forms of bambuteral and terbutaline were bioequivalent by analysis of variance, two-one sided test and 90% confidential limit.

Two-photon laser scanning microscopy of epithelial cell-modulated collagen density in engineered human lung tissue

Tissue remodeling is a complex process that can occur in response to a wound or injury. In lung tissue, abnormal remodeling can lead to permanent structural changes that are characteristic of important lung diseases such as interstitial pulmonary fibrosis and bronchial asthma. Fibroblast-mediated contraction of three-dimensional collagen gels is considered an in vitro model of tissue contraction and remodeling, and the epithelium is one factor thought to modulate this process. We studied the effects of epithelium on collagen density and contraction using two-photon laser scanning microscopy (TPLSM). TPLSM was used to image autofluorescence of collagen fibers in an engineered tissue model of the human respiratory mucosa -- a three-dimensional co-culture of human lung fibroblasts (CCD-18 lu), denatured type I collagen, and a monolayer of human alveolar epithelial cell line (A549) or human bronchial epithelial cell line (16HBE14o(-)). Tissues were imaged at days 1, 8, and 15 at 10 depths within the tissue. Gel contraction was measured concurrently with TPLSM imaging. Image analysis shows that gels without an epithelium had the fastest rate of decay of fluorescent signal, corresponding to highest collagen density. Results of the gel contraction assay show that gels without an epithelium also had the highest degree of contraction (19.8% +/- 4.0%). We conclude that epithelial cells modulate collagen density and contraction of engineered human lung tissue, and TPLSM is an effective tool to investigate this phenomenon.

The porcine and lagomorph septal cartilages: models for tissue engineering and morphologic cartilage research

Interest in reconstruction and modification of the facial cartilaginous frameworks using advanced technology and instrumentation is growing rapidly. Despite this maturing interest, no animal model has been established to provide morphologic cartilage tissue with similar characteristics to human septum in suitable quantities. The objective of this study was to characterize porcine and lagomorph (rabbit) nasal septal cartilage tissue. Both models share great similarity with their human counterpart and provide a low-cost, high-volume, and easily obtained source of bulk cartilage tissue. We present a technique for harvesting intact septal cartilages from these species, and characterize select cellular, metabolic, and physical properties using pulse-chase radiolabeling, flow cytometry, and mechanical analysis. Our selective evaluation of key tissue properties establishes these species as appropriate animal models for nasal septal cartilaginous surgery.

Photodynamic therapy of human glioma spheroids using 5-aminolevulinic acid

The response of human glioma spheroids to 5-aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) is investigated. A two-photon fluorescence microscopy technique is used to show that human glioma cells readily convert ALA to protoporphyrin IX throughout the entire spheroid volume. The central finding of this study is that the response of human glioma spheroids to ALA-mediated PDT depends not only on the total fluence, but also on the rate at which the fluence is delivered. At low fluences (< or = 50 J cm-2), lower fluence rates are more effective. At a fluence of 50 J cm-2, near-total spheroid kill is observed at fluence rates of as low as 10 mW cm-2. The fluence rate effect is not as pronounced at higher fluences (> 50 J cm-2), where a favorable response is observed throughout the range of fluence rates investigated. The clinical implications of these findings are discussed.

Photodynamic therapy of human glioma spheroids using 5-aminolevulinic acid

The response of human glioma spheroids to 5-aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) is investigated. A two-photon fluorescence microscopy technique is used to show that human glioma cells readily convert ALA to protoporphyrin IX throughout the entire spheroid volume. The central finding of this study is that the response of human glioma spheroids to ALA-mediated PDT depends not only on the total fluence, but also on the rate at which the fluence is delivered. At low fluences (< or = 50 J cm-2), lower fluence rates are more effective. At a fluence of 50 J cm-2, near-total spheroid kill is observed at fluence rates of as low as 10 mW cm-2. The fluence rate effect is not as pronounced at higher fluences (> 50 J cm-2), where a favorable response is observed throughout the range of fluence rates investigated. The clinical implications of these findings are discussed.

In vitro and in vivo comparison of argon-pumped and diode lasers for photodynamic therapy using second-generation photosensitizers

BACKGROUND AND OBJECTIVE

Three prototype microchannel-cooled stacked diode array lasers were compared with the currently used conventional argon ion laser-pumped tunable dye lasers for suitability as light sources in photodynamic therapy (PDT) treatment.

STUDY DESIGN/MATERIALS AND METHODS

The PDT response of Chinese hamster ovary (CHO-K1) cells in culture and SMT-F tumor bearing mice treated with chloro-aluminum sulfonated phthalocyanin (CASPc), benzoporphyrin derivative mono-acid (BPD-MA), and lutetium texaphyrin (Lutex) was determined using each laser light source. Survival of the CHO cells was measured using a cloning assay. Tumor regression/eradication was used to assess response in the mice.

RESULTS

Both sources of laser light produced comparable PDT responses in the two systems tested.

CONCLUSION

It would be possible to replace the currently used argon ion laser-pumped dye laser systems with the diode lasers tested.

In vitro and in vivo photosensitizing capabilities of 5-ALA versus photofrin in vascular endothelial cells

BACKGROUND AND OBJECTIVE

The objective of the present study was to evaluate the feasibility of photodynamic therapy (PDT) for complicated hemangiomas. The photosensitizing activities of 5-aminolevulinic acid (5-ALA) and Photofrin were evaluated in vitro with human dermal microvascular endothelial cells (MEC) and in vivo with the chicken cox comb.

STUDY DESIGN/MATERIALS AND METHODS

The in vitro absorption and photosensitizing activities of 5-ALA and Photofrin were examined in a MEC culture system. The percentages of MEC killed by different drug concentrations at a wavelength of 630 nm were measured by either live/dead or lactate dehydrogenase-released assays. Similarly, the in vivo biological activities of 5-ALA and Photofrin exposed to different total light dosages at 630 nm were studied by determining the amount of necrosis produced in chicken combs.

RESULTS

MEC incubated with 5-ALA at a concentration of 35 microg/ml and exposed to laser light at 630 nm at a power density of 100 mW/cm2 showed a 50% cell kill. MEC incubated with Photofrin at a concentration of 3.5 microg/ml and exposed to laser light at 630 nm at a power density of 100 mW/cm2 showed a 50% cell kill. Chicken combs that received 200 mg/kg of 5-ALA exposed to laser light at 630 nm at a power density of 100 mW/cm2 had an injury depth of 362.5+/-27.6 microm at histologic examination. Combs exposed to a power density of 100 or 120 mW/cm2 showed injury depths of 732.5+/-29.1 and 792.5+/-36.0 microm, respectively. Chicken combs that received 2.5 mg/kg of Photofrin exposed to laser light at 630 nm at a power density of 80 mW/cm2 had an injury depth of 535.6+/-22.3 microm at histologic examination. Combs exposed to a power density of 100 or 120 mW/cm2 showed injury depths of 795.8+/-32.5 and 805.2+/-49.1 microm, respectively.

CONCLUSION

Both 5-ALA and Photofrin have the capability to destroy MEC in vitro and vasculature in vivo. However, Photofrin achieved a higher degree of cell kill and tissue destruction at lower drug concentrations and at lower power densities.

Ephrins stimulate or inhibit neurite outgrowth and survival as a function of neuronal cell type

The Eph family of tyrosine kinase receptors and ligands play key roles in cell segregation and axon targeting in the developing nervous system. Interactions between the ligands and receptors cause repulsion or degeneration of receptor-positive axons from several brain regions including the retina, hippocampus, thalamus, and midbrain dopaminergic system. We extend these previous observations by showing that three A-ephrins also negatively regulate the growth of neurites from striatal and olfactory neurons. In addition to negative effects, however, we also report a trophic activity of the A-ephrins: Ephrin-A2 and A5 promote survival and neurite outgrowth of sympathetic neurons. These observations provide support to the notion that ephrins may function as either negative or positive signals in the developing nervous system.

Proteoglycan synthesis in porcine nasal cartilage grafts following Nd:YAG (lambda = 1.32 microns) laser-mediated reshaping

Mechanically deformed morphologic cartilage grafts undergo temperature-dependent stress relaxation during sustained laser irradiation resulting in stable shape changes. In this study, porcine nasal septal cartilage specimens were evaluated for viability by measuring the incorporation of Na2(35)SO4 into proteoglycan (PTG) macromolecules in whole tissue culture following laser-mediated reshaping. Synthesis rates of PTG were determined by scintillation counting lyophilized specimens and normalizing these values by total protein content. Positive controls were established by inducing chondrocyte apoptosis using prolonged exposure to nitric oxide (NO). In chondrocytes, apoptosis induced using NO resulted in significantly lower PTG synthesis rates compared to untreated native specimens. Cartilage specimens were irradiated with light emitted from a Nd:YAG laser (25 W/cm2, lambda = 1.32 microns) while recording simultaneously radiometric surface temperature, internal stress and back-scattered light intensity from a probe laser. Each specimen received one, two or three sequential laser exposures. The duration of each exposure was determined from real-time measurements of characteristic changes in back-scattered light intensity that correlate with accelerated stress relaxation. A 5 min time interval between each laser exposures allowed the cartilage specimen to return to thermal equilibrium. Average PTG synthesis rates decreased with successive laser exposures, though these were always higher than baseline rates established for NO-treated tissues, suggesting that laser-mediated cartilage reshaping acutely does not eliminate the entire population of viable chondrocytes. The reduction in PTG synthesis is correlated with the time-temperature-dependent heating profile created during laser irradiation, supporting our hypothesis that careful monitoring of laser dosimetry is required to ensure chondrocyte viability.

Development of a tetracycline controlled gene expression system in the parasitic protozoan Giardia lamblia

Giardia lamblia is a very common intestinal protozoan pathogen of humans. Recent development of gene transfection systems in G. lamblia has allowed constitutive expression of selected genes in the organism. To extend the uses of DNA transfection in G. lamblia, an inducible gene expression system was developed by integrating the bacterial tet operator-repressor elements into an episomal DNA transfection vector. Tetracycline-responsive promoters with insertions of multiple tet operator sequences in the vicinity of a synthetic ran promoter were tested for their inducibility of a luciferase reporter gene expression. Stable cell lines transfected with individual plasmid constructs were established under drug selection. By assaying luciferase activity in transfected cells in response to tetracycline, an inducible promoter with insertion of two tet operators downstream of the adjacent synthetic ran promoter was found to confer a 10-fold inducibility in gene expression with co-expression of the tet-repressor driven by a gdh promoter. To further improve its inducibility, several other synthetic promoter contexts were also tested to increase expression of the tet-repressor gene. An optimal inducibility of 50-fold was obtained when a synthetic alpha-giardin promoter was used. Fine tuning of luciferase expression was achieved by adjusting the concentration of tetracycline and duration of drug exposure. The inducible gene expression system provides us an easy way to manipulate the level of gene expression in G. lamblia in a controllable manner that could not previously be achieved.

Identification and characterization of a ran gene promoter in the protozoan pathogen Giardia lamblia

The promoter elements that regulate transcription initiation in Giardia lamblia are poorly understood. In this report, the promoter of the Giardia ran gene was studied using a luciferase expression plasmid pRANluc+ to monitor transcription efficiency. An AT-rich sequence spanning -51/-20 relative to the translation start site of the ran gene was identified and was found to be required for efficient luciferase expression by deletion and mutation mapping of pRANluc+. The -51/-20 sequence was also sufficient for promoter activity as revealed from studies on a 32-base pair synthetic promoter derived from this region. Deletion mapping of the synthetic promoter revealed two minimal promoter elements, -51/-42 and -30/-20, sufficient for 6- and 30-fold luciferase expression above background, respectively. The transcription start sites on luc+ messenger RNA were determined by the position of the synthetic promoter in the luciferase expression plasmids as shown by primer extension experiments. Results from electrophoretic mobility shift assays revealed multiple DNA-protein complexes upon binding of nuclear proteins with either DNA strand but not the double-stranded DNA derived from the ran promoter. Our results delineate the first promoter sequence of the Giardia gene (ran), which provides an excellent model for future studies on transcription regulation in this protozoan parasite.

Stable DNA transfection of the primitive protozoan pathogen Giardia lamblia

We have developed a stable DNA transfection vector pRANneo for genetic manipulation of the primitive protozoan Giardia lamblia. pRANneo was constructed by replacing the protein coding region of a Giardia ran gene with a bacterial neomycin phosphotransferase gene (neo). This plasmid was electroporated into G. lamblia, and the transfectants were selected by G418. pRANneo replicated episomally to approximately 80 copies per G. lamblia trophozoite as demonstrated by dot hybridizations, Southern hybridizations and transformations of the DpnI-treated plasmids into Escherichia coli. pRANneo/GDHluc was then constructed by incorporation of a luciferase expression system into pRANneo to persistently express firefly luciferase in G. lamblia under G418 selection. The NEO and luciferase proteins were detected in the transfected G. lamblia cells by Western blottings. The level of luciferase activity and the plasmid copy number correlated with the concentration of G418. Removal of G418 from the transfectant culture resulted in gradual loss of the plasmid and luciferase activity. The stable DNA transfection system should provide a valuable tool for genetic studies of G. lamblia.

Fulminant hepatic failure as the first manifestation of Wilson disease: a report of two cases

Two cases of fulminant hepatic failure as a first manifestation of Wilson disease are reported. They were diagnosed as acute hemolytic anemia initially, and took a fatal course despite intensive medical therapy. The main object of this report is to emphasize that Wilson disease must be included in the differential diagnosis of fulminant hepatic failure in children. Liver transplantation is the only effective means of treatment in patients presenting with fulminant hepatic failure, but this procedure is difficult to perform because of insufficient organ donation in Taiwan. The best treatment for Wilson disease is prevention through diagnosis at a presymptomatic stage, and institution of life-long therapy with D. penicillamine.

Accumulation of 5-aminolevulinic acid-induced protoporphyrin IX in normal and neoplastic human endometrial epithelial cells

The aim of this study was to evaluate 5-Aminolevulinic acid (ALA)-induced fluorescence of normal and neoplastic endometrial epithelial cells for diagnosis and photodynamic treatment. Fluorescence of ALA-induced PpIX in vitro was measured by flow cytometry in two different human endometrial adenocarcinoma cell lines and in normal cells cultivated from fresh endometrial tissue of three premenopausal patients. The cells were analysed after incubation with different concentrations of ALA during 3, 6, or 24 hours. Both tumor cell lines showed a statistically significant higher fluorescence of PpIX than normal epithelial cells after incubation with 1 mg ALA per ml medium during 24 hours. The well-differentiated cancer cells produced significantly more PpIX than the poorly differentiated cancer cells. Relative PpIX intensity of the two cancer cell lines correlated with cell proliferation rate as measured by the doubling times of the cells. Higher accumulation of Pp IX in neoplastic endometrium compared to normal endometrial epithelial cells may provide targeted biopsies and selective photodynamic destruction of neoplastic micro-lesions.

Purification and characterization of 6xHis-tagged Bm3R1 repressor of Bacillus megaterium

The bm3R1 gene-encoded repressor controls the expression of cytochrome P450BM-3 gene as well as its own expression in Bacillus megaterium. We have developed an efficient system for overexpression and purification of Bm3R1 protein by nickel ion affinity chromatography. Adding six histidine residues at either N-terminus or C-terminus of Bm3R1 repressor caused no loss of its operator DNA binding ability. We have investigated the interaction between Bm3R1(His)6 and its operator DNA by equilibrium and kinetic methods. The results showed that the apparent dissociation constant is around 1.8 x 10(-9) M and the half-life of Bm3R1(His)6-operator complex is about 50 minutes. We have also found by gel filtration chromatography that Bm3R1(His)6 may exist in low oligomeric state(s) in solution, which is competent for binding to its operator DNA.

Effect of administration route and estrogen manipulation on endometrial uptake of Photofrin porfimer sodium

OBJECTIVE

Our purpose was to evaluate the influence of the route of drug administration and target tissue vascularity on the distribution of a photosensitizer, Photofrin porfimer sodium, in the uterus.

STUDY DESIGN

The study was divided in two phases. In phase I 80 mature female rats were hormonally suppressed and then stimulated with estrogen. They were randomized to receive intravenous, intraperitoneal, or intrauterine Photofrin and killed 3, 6, 24, or 48 hours later. Drug distribution and levels were then determined. In phase II 40 female rats were randomized to receive hormonal stimulation, suppression, both, or neither. All received intrauterine Photofrin and were killed 24 hours later. Statistical analysis was performed with the unpaired t test and the two-way analysis of variance.

RESULTS

Intrauterine administration was determined to be the simplest and most effective method of delivery because it provided for optimal uptake and distribution (p = 0.05) within the uterus, at lower doses.

CONCLUSIONS

Selective localization of photosensitizer within the target tissue suggests that highly selective photodynamic destruction of endometrial tissue can be achieved. Furthermore, the combination of intrauterine administration of photosensitizer with estrogen adjuvant may minimize the most debilitating side effect of Photofrin, cutaneous phototoxicity.

Activation of macrophages by Photofrin II during photodynamic therapy

In order to obtain information about the activation of macrophages (M phi s) during photodynamic therapy (PDT), the influence of Photofrin II (Pf II) on the viability of thioglycollate-elicited murine M phi s and the subsequent generation of superoxide anion was studied. Irradiations were performed at an energy density of 5 J cm-2, a power density of 150 mW cm-2 and a wavelength of 405 nm. Viability of M phi s was assessed using the acridine orange-ethidium bromide assay. Superoxide anion generation was determined using ferricytochrome c (cyt c) and nitroblue tetrazolium (NBT) reduction. Our results indicate that the M phi s are highly susceptible to PDT as their viability is decreased to approximately 30% by 1 microgram ml-1 Pf II at the energy density indicated above. Within the first 30 min of addition of the photosensitizer, a reducing agent is generated intracellularly by the stimulation of the M phi s. An extracellular release of superoxide anion does not occur, as measured by the cyt c assay. Preincubation of the cells for 1 or 24 h with Pf II and a second challenge with phorbol myristate acetate (PMA) does not enhance the reduction of NBT. Thus, Pf II exerts an immediate effect on the M phi s which could be interpreted as a first step for subsequent reactions.

Free electron laser irradiation at 200 microns affects DNA synthesis in living cells

We describe the effect of a 200-microns wavelength free electron laser beam on the ability of asynchronized and synchronized mammalian tissue culture cells to incorporate tritiated thymidine. Compared to controls (unexposed cells), a significant proportion of exposed cells exhibited a reduction in isotope incorporation. The results suggest that this wavelength may affect DNA synthesis.

Serum erythropoietin levels after renal transplantation

We measured serum erythropoietin levels serially in 31 renal-transplant recipients treated with cyclosporine, using the recently developed recombinant human erythropoietin-based radioimmunoassay. The mean (+/- SEM) serum erythropoietin concentration in these patients before transplantation (14 +/- 2 U per liter) was similar to that in normal subjects who did not have anemia. A transient postoperative 9-fold increase (range, 0- to 74-fold) in the serum erythropoietin levels was followed by a smaller (3-fold) and sustained (28 +/- 3 days) second elevation. The initial increase occurred in the absence of graft function and was not accompanied by an erythropoietic response, whereas the second increase was associated with graft recovery and the complete resolution of the anemia. Serum erythropoietin levels returned to normal as the hematocrit rose above 0.32. Thereafter, the hematocrit continued to rise toward normal, while the serum erythropoietin levels remained normal. The patients in whom erythrocytosis or iron-deficiency anemia developed had persistently elevated serum erythropoietin levels. We conclude that in patients who have undergone renal transplantation, slight increases in endogenous erythropoietin levels induce erythropoiesis to the same extent as do large doses of exogenous erythropoietin in patients with uremia. Moreover, once initiated, erythropoiesis in renal-transplant recipients may be sustained by normal serum erythropoietin levels. These results suggest that the restoration of renal function improves the erythropoietic response to erythropoietin.

Erythropoietin in renal transplant recipients: studies based on recombinant human erythropoietin radioimmunoassay

In posttransplant patients, modest increases in endogenous EPO induce erythropoiesis similar to that observed in uremic patients who are given large doses of exogenous rHuEPO that generate vastly higher circulating EPO levels. Moreover, once it is initiated, erythropoiesis may be sustained by normal levels of EPO. These observations raise the possibility that the restoration of renal function may alter the EPO-erythropoiesis response pattern. It is also possible that the resolution of uremic anemia is dependent on factors in addition to the level of circulating EPO.