A Review of Current Uses of Amniotic Membrane Transplantation in Ophthalmic Plastic and Reconstructive Surgery

PURPOSE

To review and summarize the existing literature on the clinical applications of amniotic membrane transplantation (AMT) in ophthalmic plastic and reconstructive surgery.

METHODS

A literature review was conducted on the PubMed database using the following search terms: "amniotic membrane" and "eyelid" or "orbit" or "fornix" or "socket" or "lacrimal".

RESULTS

In total 516 articles resulted from the search, of which 62 were included. Numerous cases and case series have been published on the use of amniotic membrane transplantation for ocular surface reconstruction, eyelid and forniceal reconstruction, and cicatricial eyelid abnormalities. Surgical methods of securing the graft vary. Few comparative studies exist; some show a similar or improved result when compared to oral mucous membrane grafting for certain indications.

CONCLUSIONS

Amniotic membrane transplantation can be a useful tool for the oculoplastic surgeon when faced with a case requiring reconstruction of the posterior lamellae, particularly in patients without other graft donor sites available, and uses of AMT continue to expand. Additional studies directly comparing AMT to other reconstructive techniques would be helpful in choosing between the available surgical techniques and standardizing best practices.

P-ANCA Vasculitis Presenting with Orbital Infiltration

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) may affect the eye or orbit, and ophthalmic manifestations of AAV are associated with higher mortality than other inflammatory eye diseases. Perinuclear ANCA (p-ANCA) vasculitis is an uncommon cause of orbital inflammation. A 70-year-old woman with chronic kidney disease presented with a 1-year history of orbital mass and edema around her OD. Fundoscopy revealed 360° optic disc elevation OD. MRI orbits showed an infiltrative, intra- and extraconal lesion extending through the right orbital apex to the cavernous sinus. Labwork and orbital biopsy were consistent with p-ANCA vasculitis, and the patient's ocular symptoms improved after methylprednisolone. Diagnosis of AAV is complicated by a wide diversity of symptoms, and this case highlights an unusual presentation of p-ANCA vasculitis in the orbit. Ophthalmologists have an important role in diagnosing systemic conditions such as AAV by initiating the proper inflammatory workup.

Baseline Characteristics and Clinical Presentation of Biopsy-Proven Giant Cell Arteritis in White Compared with Black Patients

BACKGROUND

Giant cell arteritis (GCA) is the most prevalent systemic vasculitis in the elderly and can lead to permanent vision loss if left untreated. Most earlier studies have evaluated GCA in primarily white populations, and GCA was traditionally thought to occur at nearly negligible frequency in black populations. Our previous study showed that GCA may occur at similar rates in white and black patients, but little is known about the presentation of GCA in black patients. The purpose of this study is to examine baseline presentation of biopsy-proven GCA (BP-GCA) in a tertiary care center-based population with a sizeable proportion of black patients.

METHODS

Retrospective study from a single academic institution of a previously described cohort of BP-GCA. Presenting symptoms, laboratory findings, and GCA Calculator Risk score were compared in black and white patients with BP-GCA.

RESULTS

Among 85 patients with biopsy-proven GCA, 71 (84%) were white and 12 (14%) were black. White patients had higher rates of elevated platelet count (34% vs 0%, P = 0.04), whereas black patients had higher rates of diabetes mellitus (67% vs 12%, P < 0.001). There were no statistically significant differences in age, gender, biopsy classification (active vs healed arteritis), cranial symptoms, visual symptoms/ophthalmic findings, rates of abnormal erythrocyte sedimentation rate or C-reactive protein, unintentional weight loss, polymyalgia rheumatica, or GCA risk calculator score.

CONCLUSIONS

Presenting features of GCA were similar between white and black patients in our cohort, except for rates of abnormal platelet level and diabetes. Physicians should feel comfortable relying on the usual clinical features for the diagnosis of GCA independent of race.

[Study on formulation and revision of detection methods of "Standards for indoor air quality (GB/T 18883-2022)" in China]

The formulation and revision of the detection methods of indoor air quality standards is an important, rigorous and delicate endeavor. This paper introduced the formulation and revision of the detection methods of the standards for indoor air quality (GB/T 18883-2022), focusing on the revision process, revision principles, main adjustments and technical points of some key indicators to facilitate users to better understand and apply the detection methods in standards for indoor air quality (GB/T 18883-2022).

The Nictavi Tarsus Patch: A New Device for Achieving Temporary Eyelid Closure in Lagophthalmos

Purpose

To evaluate the effectiveness, tolerability, and safety of the Nictavi Tarsus Patch™ (NTP) in inducing temporary eyelid closure for the management of lagophthalmos in the pediatric and young adult population.

Methods

We prospectively enrolled 20 patients <21 years of age who had previously been managed for lagophthalmos to trial the NTP in clinic. Inter-palpebral fissure distance (IPFD) was compared before and after the placement of the NTP in the eyes-closed position using paired t-tests. Subjects then underwent a 3-night home trial with the NTP, and parent and subject perceptions of effectiveness, comfort, and complications with the patch were analyzed using Likert scale survey questions.

Results

Twenty subjects ages 2-20 years with paralytic (65%) and non-paralytic (35%) lagophthalmos were enrolled. The NTP improved lagophthalmos from a mean pre-placement IPFD of 3.3 mm to post-placement IPFD of 0.4 mm (p < 0.01). Overall, 80% of subjects achieved successful eyelid closure defined as ≤1 mm of post-placement IPFD. When stratified by subtype, 100% of subjects with paralytic lagophthalmos achieved successful eyelid closure compared to 71% of subjects with non-paralytic lagophthalmos. On a scale of 1 (worst) to 5 (best), parents rated the NTP at 4.3±0.7 for comfort while wearing, 4.3±1.0 for comfort in removing, 4.6±0.7 for ease of use, and 4.3±0.9 for effectiveness. Ninety-three percent of parents reported preferring NTP to other eyelid closure methods previously tried and indicated that they would use it again.

Conclusion

The NTP is an effective, tolerable, and safe method of eyelid closure for children and young adults.

Demographic and physiological factors associated with clinically significant eyelid edema in patients following upper eyelid surgery

PURPOSE

To investigate demographic and physiological variables associated with clinically significant edema after upper eyelid surgery.

METHODS

A retrospective chart review was performed on patients who underwent blepharoplasty or external levator advancement with or without lid crease formation between January 2018 and January 2021 at the University of Southern California. Age, sex, pertinent medical history (medications causing edema and comorbidities), and pertinent surgical procedures were all collected. Postoperative photos were graded by two independent physician graders on a newly developed photographic scale ranging from 0 (no edema) to 3 (severe edema). Clinically significant edema of the eyelids was defined as Grade 3 edema at any postoperative point or ≥ Grade 1 edema after 90 days post operation. Patients without postoperative photos were excluded. Mann-Whitney U test, Fisher's exact test, and χ2 test were used to compare groups with and without significant edema. All analyses were conducted using SAS version 9.4 (SAS Institute Inc.) with α=0.05.

RESULTS

Out of 217 patients, East Asian participants had higher odds of developing edema than White participants (odds ratio, 7.92; CI, 3.15-19.93, p < 0.0001) and Hispanic participants (odds ratio, 3.47; CI, 1.51-7.97, p = 0.003). Southeast Asian participants also had higher odds of developing CSEE than White participants (odds ratio, 6.19; CI, 1.71-22.43, p = 0.006). Fifty-four (24.9%) patients had clinically significant edema. Although BMI, medical comorbidities, medication use, and age did not affect edema, there was a statistically significant relationship between race and incidence of edema (p = 0.0001). Those in the CSEE group were also more likely to require reoperation (p = 0.0143).

CONCLUSIONS

There is a statistically significant relationship between Asian race and the incidence of clinically significant eyelid edema. CSEE is associated with a higher incidence of reoperation.

Presenting Features of Giant Cell Arteritis with Active Versus Healed Arteritis on Biopsy

Giant cell arteritis (GCA) is often categorised as "active" or "healed" on temporal artery biopsy (TAB). The purpose of this study was to compare the initial clinical presentation of patients with GCA according to active versus healed arteritis on TAB. A retrospective chart review was performed for patients with biopsy-proven GCA (BP-GCA) at a single academic medical institution from a previously reported cohort. The arteritis on TAB was categorised as "active" or "healed" based on the pathological reports. Demographic information, clinical presentation, past medical history, and test results were collected from the date of TAB. These baseline characteristics were entered into the GCA Risk Calculator. Of 85 patients with BP-GCA, 80% had active and 20% had healed disease according to histopathology. A higher percentage of those with active arteritis had ischaemic optic neuropathy (ION) (36% versus 6%, p = .03), elevated erythrocyte sedimentation rates (92% versus 63%, p = .01), elevated C-reactive protein levels (79% versus 46%, p = .049), GCA risk score > 7.5% (99% sensitivity, 100% versus 71%, p < .001), higher mean GCA risk calculator scores (neural network p = .001; logistic regression p = .002). Patients with healed arteritis were less likely to have visual manifestations than the active arteritis group (38% versus 71%, p = .04). Patients with active vasculitis on biopsy had higher rates of ION and elevated inflammatory markers, as well as higher predictive scores from the GCA risk calculator. Further research is needed regarding correlation of biopsy findings and risk of complications or relapses.

Lateral orbital wall anomaly in a patient with thyroid eye disease

An isolated defect in the lateral orbital wall is an uncommon occurrence, although cases of orbital floor, roof, and medial wall spontaneous dehiscence have been described in the literature. Here, we describe a lateral orbital wall defect in a patient with thyroid eye disease - which may be related to bony remodeling or may represent a rare congenital anomaly. Computed tomography (CT) prior to decompression surgery revealed a defect in the left lateral orbital wall. At the time of orbital decompression, prolapse of buccal fat into the orbit was noted once the subperiosteal plane was entered along the lateral orbital wall in the area of this bony defect. Literature review revealed only a few previous reports of lateral wall abnormalities, including two involving the inferior orbital fissure; one other case was associated with Down syndrome, and other reports consist of sphenoid hypoplasia associated with neurofibromatosis.

Perioperative Considerations for Antithrombotic Therapy in Oculofacial Surgery: A Review of Current Evidence and Practice Guidelines

PURPOSE

Recent survey studies have demonstrated wide variability in practice patterns regarding the management of antithrombotic medications in oculofacial plastic surgery. Current evidence and consensus guidelines are reviewed to guide perioperative management of antithrombotic medications.

METHODS

Comprehensive literature review of PubMed database on perioperative use of antithrombotic medication.

RESULTS/CONCLUSIONS

Perioperative antithrombotic management is largely guided by retrospective studies, consensus recommendations, and trials in other surgical fields due to the limited number of studies in oculoplastic surgery. This review summarizes evidence-based recommendations from related medical specialties and provides context for surgeons to tailor antithrombotic medication management based on patient's individual risk. The decision to continue or cease antithrombotic medications prior to surgery requires a careful understanding of risk: risk of intraoperative or postoperative bleeding versus risk of a perioperative thromboembolic event. Cessation and resumption of antithrombotic medications after surgery should always be individualized based on the patient's thrombotic risk, surgical and postoperative risk of bleeding, and the particular drugs involved, in conjunction with the prescribing doctors. In general, we recommend that high thromboembolic risk patients undergoing high bleeding risk procedures (orbital or lacrimal surgery) may stop antiplatelet agents, direct oral anticoagulants, and warfarin including bridging warfarin with low-molecular weight heparin. Low-risk patients, regardless of type of procedure performed, may stop all agents. Decision on perioperative management of antithrombotic medications should be made in conjunction with patient's internist, cardiologist, hematologist, or other involved physicians which may limit the role of guidelines depending on patient risk and should be used on a case-by-case basis. Further studies are needed to provide oculofacial-specific evidence-based guidelines.

Aspiration as a Novel Technique to Address Facial and Periocular Myiasis

Suction aspiration, which has not yet been described in the treatment for myiasis in the periorbital and facial regions, was used to achieve rapid resolution of maggot burden in a 78-year-old patient who presented with a large ulcerated squamous cell carcinoma of the face. This technique also facilitates submission of parasite samples for further analysis. Suction aspiration had no complications, such as significant residual ruptured maggots in the wound or eye injury. Suction aspiration is a safe and efficient technique to reduce maggot burden that has advantages over classic myiasis treatments, especially near the eyes and airway.

Thyroid Eye Disease-Related Epiblepharon: A Comparative Case Study

PURPOSE

This study describes the clinical features and management of epiblepharon as a manifestation of thyroid eye disease (TED). In addition, we compare the frequency and age in Asian and non-Asian patients, and discuss pathophysiologic implications.

DESIGN

Retrospective case-control study.

METHODS

This is a single-center retrospective review that identified 172 adult patients (age 19 to 83) with TED that were consecutively evaluated by 1 author (T.J.M.) between December 2015 and July 2018. Diagnosis of TED and epiblepharon was based upon clinical assessment as documented in the medical record.

RESULTS

In a cohort of 172 patients (mean age 52; 138 female), 3 patients with acquired epiblepharon were identified, all of whom were Asian. The proportion of affected Asian patients (3/of 17, 17.6%) was significantly higher than that of non-Asian patients (0/155, P < 0.001). Patients with epiblepharon were also significantly younger than those without epiblepharon, 29.7 ± 2.1 versus 48.7 ± 13 years of age (P = 0.026). All 3 patients underwent surgical correction with lateral canthoplasty and anterior lamellar pretarsal fixation with successful outcomes.

CONCLUSIONS

Lower eyelid epiblepharon may occur in TED. In our clinic-based population, this finding was significantly more frequent in Asian patients and in younger patients. Relieving horizontal tension in conjunction with anterior lamella pretarsal fixation is an effective method of correcting TED-associated epiblepharon.

Association of Giant Cell Arteritis With Race

Importance

Giant cell arteritis (GCA) is the most common vasculitis in adults and is associated with significant morbidity and mortality. Its incidence has been carefully studied in white populations, yet its relevance among other racial and ethnic groups is less well known.

Objective

To examine the incidence of biopsy-proven GCA (BP-GCA) in a tertiary care center-based population with a sizeable proportion of black patients.

Design, Setting, and Participants

This retrospective cohort study identified all patients who underwent temporal artery biopsy (TAB) from July 1, 2007, through September 30, 2017, using the electronic medical record system at the Johns Hopkins Wilmer Eye Institute. Associations between self-reported race, sex, and age were explored and compared with all other patients attending the hospital over the same period. Data were analyzed from November 1, 2017, through July 31, 2018.

Main Outcomes and Measures

Estimated incidence rates of BP-GCA in black and white patients.

Results

Among 586 patients who underwent TAB (mean [SD] age, 70.5 [11.1] years; age range, 32-103 years; 423 [72.2%] women), 167 (28.5%) were black, 382 (65.2%) were white, and 37 (6.3%) were other or unknown. Of 573 individuals 50 years and older, 92 (16.1%) had BP-GCA; 14 were black (8.4% of all black patients undergoing testing) and 75 were white (19.6% of all white patients undergoing testing). Crude annual incidence rates for BP-GCA were 2.9 (95% CI, 1.3-5.5) per 100 000 for black and 4.2 (95% CI, 3.0-5.6) per 100 000 for white patients within the study population. Population-adjusted age- and sex-standardized incidence rates were 3.1 (95% CI, 1.0-5.2) and 3.6 (95% CI, 2.5-4.7) per 100 000 for black and white patients, respectively (difference, 0.5; 95% CI, -1.7 to 2.7; P = .70). The incidence rate ratio was 1.9 in women compared with men (95% CI, 1.1-3.4; P = .03) but was not significant in white compared with black patients (1.2; 95% CI, 0.6-2.4; P = .66).

Conclusions and Relevance

In our cohort, BP-GCA occurred more commonly in women, but rates were similar between races. These findings do not appear to support the conclusion that GCA occurs more frequently in white compared with black patients.

Delayed Orbital Emphysema Mimicking Orbital Cellulitis: An Uncommon Complication of Dental Surgery

A 79-year-old man presented to the ophthalmology clinic with acute-onset left orbital and periorbital swelling, 6 days following surgery to revise a zygomatic implant to anchor his dentures. On evaluation, there was left eye proptosis with ipsilateral facial crepitus. Emphysema was confirmed on computed tomography. With visual function and motility remaining intact, he was observed without intervention. Within 2 weeks, his evaluation returned to baseline. Periorbital emphysema is a rare complication of dental procedures. Awareness of this potential complication enables timely diagnosis and avoidance of unnecessary therapy.

Temperature changes associated with bone drilling in an orbital model: comparison of ultrasonic bone curette and conventional high-speed rotational drill

Purpose: Thermal injury to the optic nerve is a potential complication of bony decompression of the orbital apex. An animal model was used to compare and contrast temperature change while removing orbital bone with ultrasonic and conventional drills. Methods: Two devices, Sonopet ultrasonic bone curette and TPS CORE Micro drill, were used to remove bone from six unpreserved exenterated porcine orbits at fixed distances from the optic canal while temperature was recorded. Increasing irrigation flow rate and decreasing saline temperature with the ultrasonic bone curette were also investigated. Results: The mean change in temperature at the optic canal using the ultrasonic bone curette with 18 ml/min 24°C irrigation was +7.2 ± 3.3°C (range 3.3-12.7°C) at 60 s, and using the rotational drill was +1.7 ± 1.3°C (range 0.1-3.3°C), representing a statistically significant increase above baseline for both drills (p < 0.01 for each). The difference in temperature change between drills was statistically significant (p < 0.01). When irrigation fluid was changed from room temperature saline (24°C), rate 18 ml/min to chilled (10°C) irrigation saline, rate 40 ml/min, the magnitude of the mean temperature increase was reduced by 3.1°C, p < 0.05. Conclusions: In this orbital decompression model, both ultrasonic and rotational drills induced a rise in temperature. This increase was significantly greater with the ultrasonic bone curette, measuring up to 13.7°C. Clinicians should be aware of the potential for temperature spikes when decompressing the orbital apex. Increasing irrigation flow rate and using chilled saline may mitigate increases in temperature.

Orbital Disease in Neuro-Ophthalmology

Many abnormalities of the orbit present with neuro-ophthalmic findings, such as impaired ocular motility or alignment, and sensory changes, including optic neuropathy. Comprehensive coverage of all orbital diseases is beyond the scope of this article. This review focuses on diagnosis and management of the most common and the most vision- or life-threatening orbital conditions as well as more recently discovered entities and points of active controversy. These conditions include orbital trauma, vascular disease, inflammatory and infectious diseases, and neoplasms. Common presenting symptoms and associated neuro-orbital diseases also are summarized.

Ten-year incidence rates of age-related cataract in the Age-Related Eye Disease Study (AREDS): AREDS report no. 33

PURPOSE

To investigate the long-term incidence of age-related cataract and cataract surgery in the Age-Related Eye Disease Study (AREDS) cohort.

METHODS

Baseline and annual lens photographs of participants, aged 55-80 years, were graded centrally for nuclear, cortical, and posterior subcapsular (PSC) lens opacities using the AREDS System for Classifying Cataracts. Progression from a baseline status of no or mild lens opacity to at least moderate severity was analyzed and cumulative incidence estimated rates were calculated for each lens opacity type and cataract surgery stratified by age, sex, race, age-related macular degeneration category, multivitamin (Centrum) use and history of diabetes.

RESULTS

The ten-year cumulative incidence was 43.6% for any cataract, 23.1% for nuclear cataract, 22.0% for cortical cataract, 13.1% for PSC cataract, and 26.8% for cataract surgery. The 5- and 10-year incidence rates of all cataract types and cataract surgery were significantly higher with increasing age. Females had a higher incidence of any, nuclear and cortical cataract and cataract surgery (p = 0.02-0.05). Incidence of cortical cataract was higher in non-white participants (p = 0.001).

CONCLUSIONS

These results are largely consistent with the results of previous observational studies. Long-term incidence rates of type-specific cataract can be useful in designing clinical studies of age-related cataract.

Risk factors associated with incident cataracts and cataract surgery in the Age-related Eye Disease Study (AREDS): AREDS report number 32

OBJECTIVE

To investigate potential risk factors associated with incident nuclear, cortical, and posterior subcapsular (PSC) cataracts and cataract surgery in participants in the Age-Related Eye Disease Study (AREDS).

DESIGN

Clinic-based prospective cohort study.

PARTICIPANTS

Persons (n = 4425) 55 to 80 years of age enrolled in a controlled clinical trial of antioxidant vitamins and minerals, AREDS, for age-related macular degeneration and cataract.

METHODS

Lens photographs were graded centrally for nuclear, cortical, and PSC opacities using the AREDS system for classifying cataracts. Type-specific incident cataracts were defined as an increase in cataract grade from none or mild at baseline to a grade of moderate at follow-up, also with a grade of at least moderate at the final visit, or cataract surgery. Cox regression analyses were used to assess baseline risk factors associated with type-specific opacities and cataract surgery.

MAIN OUTCOME MEASURES

Moderate cataract was defined as a grade of 4.0 or more for nuclear opacity, 10% or more involvement within the full visible lens for cortical opacity, and 5% or more involvement of the central 5-mm circle of the lens for PSC opacity. These were graded on baseline and annual lens photographs.

RESULTS

A clinic-based cohort of 4425 persons 55 to 80 years of age at baseline was followed up for an average of 9.8±2.4 years. The following associations were found: increasing age with increased risk of all types of cataract and cataract surgery; males with increased risk of PSC and decreased risk of cortical cataracts; nonwhite persons with increased risk of cortical cataract; hyperopia with decreased risk of PSC, nuclear cataract, and cataract surgery; Centrum (Wyeth Consumer Healthcare, Madison, NJ) use with decreased risk of nuclear cataract; diabetes with increased risk of cortical, PSC cataract, and cataract surgery; higher educational level with decreased risk of cortical cataract; and smoking with increased risk of cortical cataract and cataract surgery. Estrogen replacement therapy in female participants increased the risk of cataract surgery.

CONCLUSIONS

These findings largely are consistent with the results of previous studies, providing further evidence for possible modifiable risk factors for age-related cataract.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Distinct signature of altered homeostasis in aging rod photoreceptors: implications for retinal diseases

Background

Advanced age contributes to clinical manifestations of many retinopathies and represents a major risk factor for age-related macular degeneration, a leading cause of visual impairment and blindness in the elderly. Rod photoreceptors are especially vulnerable to genetic defects and changes in microenvironment, and are among the first neurons to die in normal aging and in many retinal degenerative diseases. The molecular mechanisms underlying rod photoreceptor vulnerability and potential biomarkers of the aging process in this highly specialized cell type are unknown.

Methodology/Principal Findings

To discover aging-associated adaptations that may influence rod function, we have generated gene expression profiles of purified rod photoreceptors from mouse retina at young adult to early stages of aging (1.5, 5, and 12 month old mice). We identified 375 genes that showed differential expression in rods from 5 and 12 month old mouse retina compared to that of 1.5 month old retina. Quantitative RT-PCR experiments validated expression change for a majority of the 25 genes that were examined. Macroanalysis of differentially expressed genes using gene class testing and protein interaction networks revealed overrepresentation of cellular pathways that are potentially photoreceptor-specific (angiogenesis and lipid/retinoid metabolism), in addition to age-related pathways previously described in several tissue types (oxidative phosphorylation, stress and immune response).

Conclusions/Significance

Our study suggests a progressive shift in cellular homeostasis that may underlie aging-associated functional decline in rod photoreceptors and contribute to a more permissive state for pathological processes involved in retinal diseases.

beta2-Subunit-containing nicotinic acetylcholine receptors are involved in nicotine-induced increases in conditioned reinforcement but not progressive ratio responding for food in C57BL/6 mice

RATIONALE

Nicotine administration potentiates conditioned reinforcement in rats, an effect that persists for weeks after chronic exposure. Little is known regarding the nicotinic receptor subtypes that may mediate this effect.

OBJECTIVE

The purpose of this study was to determine whether beta2-subunit-containing nicotinic acetylcholine receptors (beta2*nAChRs) are necessary for lasting effects of nicotine on conditioned and primary reinforcement in mice.

METHODS

Beta2 knockout (beta2KO) and wild-type (WT) mice received 14 days of nicotine exposure (NIC, 200 microg/ml in 2% saccharin) or saccharin alone (SAC) in their drinking water. Five days later, mice received paired presentations of a conditioned stimulus (CS) with water unconditioned stimulus (US) or explicitly unpaired presentations of the CS and US during Pavlovian discriminative approach training. Training was followed by two conditioned reinforcement tests. Mice were subsequently tested for food-reinforced responding in the absence of explicit cues followed by a progressive ratio test.

RESULTS

During conditioned reinforcement testing, only mice in the paired condition showed increased responding in the CS-reinforced aperture over inactive apertures. WT-NIC mice showed enhanced conditioned reinforcement compared to WT-SAC animals. beta2KO-SAC mice showed elevated conditioned reinforcement compared to WT-SAC subjects, but beta2KO-NIC and beta2KO-SAC mice did not differ in responding with conditioned reinforcement. Prior nicotine exposure did not alter food-reinforced responding but resulted in elevated break points for food in both genotypes.

CONCLUSION

These data show that nicotine exposure enhances conditioned reinforcement in mice and indicate that beta2*nAChRs are necessary for nicotine-dependent enhancement of incentive aspects of motivation but not motivation for primary reinforcement measured by progressive ratio responding.

Structural investigation of catalyst deactivation of Pt/SDB for catalytic oxidation of VOC-containing wastewater

The stability of styrene-divinyl benzene copolymer (SDB)-supported Pt (Pt/SDB) catalysts for destruction of volatile-organic-compound (VOC) in wastewater was examined. The test reaction was wet oxidation of water-containing aliphatic alcohol and formaldehyde at 140 degrees C and 90 psig for 40 h. The catalytic performance tests indicated that activity of the Pt/SDB catalysts could be maintained for VOC concentration of 3 wt.%, whereas the catalysts deactivated rapidly for 10 wt.% VOC containing wastewater. In order to investigate the nature of catalyst deactivation, extended X-ray absorption fine structure (EXAFS) and X-ray absorption near edge (XANES) spectroscopy were used to characterize the fresh and used catalysts. After the reaction, there is no oxidation of Pt clusters observed in EXAFS and XANES spectroscopy suggesting that the oxidation reaction takes places via the adsorbed oxygen. The spectroscopy results further indicated that deactivation of the catalysts were mainly caused by the increase of Pd particle size. After the reaction, the Pt-Pt coordination number has no significant change for the 3 wt.% wastewater whereas increase from 5.6 to 6.2 for 10 wt.% wastewater. Combined with the fact that the catalysts fractured during the reactions, we suggested that Pt agglomeration was mainly caused by thermal migration of the metal clusters.

The role of vascular endothelial growth factor (VEGF) in vasculogenesis, angiogenesis, and hematopoiesis in zebrafish development

Vascular endothelial growth factor (VEGF, VEGF-A), a selective mitogen for endothelial cells is a critical factor for vascular development. Two isoforms that differ in the presence of exons 6 and 7, Vegf(165) and Vegf(121), are the dominant forms expressed in zebrafish embryo. Simultaneous overexpression of both isoforms in the embryo results in increased production of flk1, tie1, scl, and gata1 transcripts, indicating a stimulation of both endothelial and hematopoietic lineages. We also demonstrate that vegf can stimulate hematopoiesis in zebrafish by promoting the formation of terminally differentiated red blood cells. Simultaneous overexpression of both isoforms also causes ectopic vasculature and blood cells in many of the injected embryos as well as pericardial edema in later stage embryos. Overexpression of vegf also resulted in earlier onset of flk1, tie1, scl, and gata1 expression in the embryo, indicating a possible role of vegf in stimulating the differentiation of both vascular and hematopoietic lineages. Co-injection of RNAs for both isoforms results in increased expression of three of these markers over and above that observed when either RNA is singly injected and analysis of vegf expression in the notochord mutants no tail and floating head suggests that the notochord patterns the formation of the dorsal aorta by stimulating adjacent somite cells to express vegf, which in turn functions as a signal in dorsal aorta patterning. Finally, studies of vegf expression in cloche mutant indicate that vegf expression is generally independent of cloche function. These results show that in the zebrafish embryo, vegf can not only stimulate endothelial cell differentiation but also hematopoiesis. Moreover, these effects are most dramatic when both vegf isoforms are co-expressed, indicating a synergistic effect of the expression of the two forms of the VEGF protein.

Purification and properties of Aquifex aeolicus DNA polymerase expressed in Escherichia coli

The gene encoding Aquifex aeolicus (Aae) DNA polymerase was expressed under the control of the trp promoter on a high-copy plasmid, pTRPNS, in Escherichia coli. The expressed enzyme was purified 11-fold with a 13.8% yield and a specific activity of 2268.3 U mg(-1). The optimum pH of the enzyme was 6.8-7.2. The optimal concentrations of KCl and Mg(2+) were 20-30 mM and 4-5 mM, respectively. Aae DNA polymerase contained a double-strand-dependent 3'-->5' proofreading exonuclease activity but lacked any detectable 5'-->3' exonuclease activity.

Differential expression of TGF-beta, IL-2, and other cytokines in the CNS of Theiler's murine encephalomyelitis virus-infected susceptible and resistant strains of mice

Intracranial inoculation of susceptible SJL mice with Theiler's murine encephalomyelitis virus (TMEV) results in biphasic disease consisting of early acute disease, followed by late chronic demyelinating disease, associated with mononuclear infiltrates and demyelinating lesions. In contrast, resistant C57BL/6 (B6) mice develop only early acute disease. We employed cytokine-specific RT-PCR to determine the expression of cytokine transcripts in the CNS of TMEV-infected SJL and B6 mice. During early acute disease, we have found a strong proinflammatory (Th1) cytokine response in the CNS of both TMEV-infected SJL and B6 mice, demonstrated by the expression of transcripts for IFN-gamma, IL-1, IL-6, IL-12p40, and TNF-alpha. At 8 days postinfection (p.i.), TGF-beta1 and TNF-alpha transcripts were present at significantly higher levels (P < 0.01) in the CNS of SJL susceptible mice in comparison to those found in the CNS of B6 mice. Immunohistochemical staining revealed that TGF-beta protein was expressed in leptomeningeal mononuclear inflammatory cell infiltrates in the brain of SJL mice but not in B6 mice, at 8 days p.i. TGF-beta may be responsible for the failure of SJL mice to develop an effective anti-TMEV CTL response. During late chronic demyelinating disease, high levels of proinflammatory Th1 cytokines were found in the CNS of SJL mice, but not B6 mice. Significantly higher levels (P < 0.01) of anti-inflammatory cytokine transcripts (IL-4, IL-5, and IL-10 (Th2 cytokines) and TGF-beta) were found in the spinal cord of TMEV-infected SJL mice with chronic demyelinating disease than in the spinal cord of B6 mice during the same time period (39 or 60 days p.i.). These anti-inflammatory cytokines may contribute to the downregulation of the proinflammatory response in SJL mice. High levels of IL-2 transcripts and protein appeared transiently in the spinal cord of TMEV-infected SJL mice before the onset of demyelinating disease and coincided with an influx of new T cells into the CNS and/or expansion of remaining T cells that have not been eliminated after viral clearance.

Proliferative actinic keratosis: three representative cases

OBJECTIVE

This article describes a new subtype of actinic keratosis that exhibits proliferative characteristics both histologically and clinically. We describe three representative cases occuring in the presence of infiltrative squamous cell carcinoma (SCC) and/or basal cell carcinoma (BCC).

METHODS

Histories of each lesion in the three cases discussed were obtained. The lesions were removed by Mohs micrographic surgery. Permanent sections, stained with hematoxylin and eosin, were examined and studied under light microscopy.

RESULTS

All three lesions had failed conventional treatment with liquid nitrogen and/or 5-fluorouracil (5-FU). Histologic examination of the lesions revealed sheets of dysplastic cells growing along the basal layer of the epidermis and migrating down hair follicles and sweat ducts. An associated infiltrative SCC and/or BCC was found in each case.

CONCLUSIONS

Proliferative actinic keratosis is resistant to standard therapies because of deep migration of abnormal cells along hair follicles and sweat ducts. It has a strong propensity to develop infiltrative SCC and may occur concomitantly with BCC.

Granuloma annulare localized to the palms

Granuloma annulare typically affects the hands and the feet, sparing the volar surfaces. A case of granuloma annulare localized to the palms is described.

Scleromyxedema: treatment with interferon alfa

Scleromyxedema is a variant of papular mucinosis characterized by fibroblast proliferation and mucin deposition in the dermis. Historically, it has been very difficult to treat and can cause significant morbidity and mortality with systemic involvement. We describe a case of a woman with scleromyxedema and systemic manifestations treated with interferon alfa. Her skin responded very well to therapy within 3 months; however, her systemic manifestations showed little change. We conclude that interferon alfa may be a useful therapy for patients with scleromyxedema, particularly if the disease process is limited to the skin.

The use of luciferase as a reporter for response of plant cells to the fireblight pathogen Erwinia amylovora

We have introduced the gene encoding luciferase from Photinus pyralis into pear and tobacco cells in order to judge the reaction of plant tissue to damaging conditions such as incubation at high temperature or inoculation with a pathogen. The constitutive expression of the luciferase gene via a strong promoter slowly decreased during propagation of the transformed pear cell line. After various stress treatments the resulting luciferase activity and the ATP content of the plant cells were determined by bioluminescence and found to correspond to each other. Inoculation of transformed pear cells with Erwinia amylovora resulted in a continuous decrease of luciferase activity in contrast to tobacco cells, where the enzyme activity was significantly higher in the first period after inoculation with bacteria compared to the untreated control cells. The pattern of the luciferase activity reflected the slow damage of the host-plant cells by E. amylovora and the elevated metabolism of the non-host cells after inoculation with the pathogen.