Multimodal imaging of white preretinal lesions in atypical familial exudative vitreoretinopathy: Case report and literature review.

Purpose: To report a rare clinical finding of preretinal granules associated with atypical familial exudative vitreoretinopathy (FEVR) and perform a review of the literature. Observations: An asymptomatic 18-year-old male was referred for unilateral peripheral avascular retina evaluation in association with presumed FEVR. He was first noted to have white preretinal granules on fundus examination at five years of age. The lesions remained unchanged over the subsequent years. Genetic testing did not reveal a pathogenic or likely pathogenic variant in a known FEVR gene. A review of the literature revealed five other cases of FEVR with similar findings. Conclusions and Importance: Literature review suggests preretinal granules may present rarely in FEVR. Negative genetic screening of known FEVR genes in our patient with atypical FEVR suggests either a molecularly distinct etiology supporting the rarity of this association with FEVR or, alternatively, the presence of granules in developmental retinal vascular anomalies that are not specific to FEVR. Future study and genetic testing is necessary to better understand the cause of these preretinal granules and the clinical manifestations of FEVR.

Architecture and regulation of filamentous human cystathionine beta-synthase.

Cystathionine beta-synthase (CBS) is an essential metabolic enzyme across all domains of life for the production of glutathione, cysteine, and hydrogen sulfide. Appended to the conserved catalytic domain of human CBS is a regulatory domain that modulates activity by S-adenosyl-L-methionine (SAM) and promotes oligomerisation. Here we show using cryo-electron microscopy that full-length human CBS in the basal and SAM-bound activated states polymerises as filaments mediated by a conserved regulatory domain loop. In the basal state, CBS regulatory domains sterically block the catalytic domain active site, resulting in a low-activity filament with three CBS dimers per turn. This steric block is removed when in the activated state, one SAM molecule binds to the regulatory domain, forming a high-activity filament with two CBS dimers per turn. These large conformational changes result in a central filament of SAM-stabilised regulatory domains at the core, decorated with highly flexible catalytic domains. Polymerisation stabilises CBS and reduces thermal denaturation. In PC-3 cells, we observed nutrient-responsive CBS filamentation that disassembles when methionine is depleted and reversed in the presence of SAM. Together our findings extend our understanding of CBS enzyme regulation, and open new avenues for investigating the pathogenic mechanism and therapeutic opportunities for CBS-associated disorders.

Relentless Placoid Chorioretinitis With Branch Retinal Vein Occlusion and Secondary Peripheral Retinal Neovascularization.

Purpose: We report a case of relentless placoid chorioretinitis (RPC) that developed branch retinal vein occlusion and peripheral retinal neovascularization in one eye. Methods: A case report is presented. Results: A 33-year-old healthy man presented with decreased visual acuity (20/150) in both eyes. Slit-lamp examination revealed anterior chamber and vitreous inflammation. Multiple yellow-white lesions were evident in the macula and scattered throughout the fundus. Following workup, a diagnosis of RPC was made. The patient was started on Pred Forte (prednisolone acetate 1%) and atropine drops. Three months later, visual acuity improved to 20/70 and 20/100 in the right and left eyes, respectively. At this time, fundus examination and fluorescein angiography revealed peripheral retinal neovascularization. Sectoral scatter laser photocoagulation was performed in the areas of nonperfusion. Conclusions: We describe a novel presentation of RPC associated with branch retinal vein occlusion and retinal neovascularization. Although the pathophysiology of RPC is believed to be primarily a choroidal vasculitis, retinal vascular changes may also occur, as observed in other white dot syndromes.

Morphological multivariate cluster analysis of murine retinal ganglion cells selectively expressing yellow fluorescent protein.

Optic neuropathies, such as glaucoma, lead to retinal ganglion cell (RGC) death. Transgenic mouse strains that express fluorescent proteins under the control of the Thy1 promoter have permitted single RGC imaging. Specifically, in one strain of mice expressing yellow fluorescent protein (Thy1-YFP), fluorescence is expressed in only 0.2% of RGCs. This reduced expression allows visualization of the full dendritic arbour of YFP-expressing RGCs, facilitating the investigation of structural changes. As susceptibility amongst RGCs varies with morphology and subtype, labelling methods should ideally non-discriminately label RGCs to accurately determine the effects of experimental glaucoma. This study therefore sought to determine morphological subtypes of RGCs in the Thy1-YFP mouse strain. Retinas from Thy1-YFP mice were imaged ex vivo with fluorescence microscopy. With Sholl analysis, a technique for quantifying the morphology of individual neurons, the dendritic field (DF), area under the curve (AUC), normalized AUC (Nav), peak number of intersections (PNI), and skew for single RGCs were computed. The distance of the RGC from the optic nerve head (dONH) was also measured. These morphological parameters were inputted into a multivariate cluster analysis to determine the optimal number of clusters to group all RGCs analyzed, which were then grouped into "Small", "Medium", and "Large" sized cluster groups according to increasing DF size. A total of 178 RGCs from 10 retinas of 8 mice were analyzed from which the cluster analysis identified 13 clusters. Eighty-eight (49%), 77 (43.2%), and 13 (7.3%) RGCs were grouped into small, medium and large clusters, respectively. Clusters 1-6 had small DFs. Clusters 1 and 3 had the lowest AUC and Nav. Clusters 2, 3, and 5 had asymmetric DFs while Clusters 3, 5, and 6 were distal to the ONH. Clusters 7-11 had medium DFs; of these, Clusters 7 and 10 had the lowest AUC, Clusters 8 and 10 had the highest skew, and Clusters 7 and 11 were closest to the ONH. Clusters 12 and 13 had large DFs. Both had low skew and high AUC. High PNI and dONH distinguished Cluster 12 from Cluster 13. We present the largest study to date examining YFP expression in RGCs of transgenic Thy1-YFP mice. Among the 13 clusters, there was a wide range of morphological features with further variation within size categories. Our findings support the notion that YFP is expressed non-discriminatingly in RGCs of Thy1-YFP transgenic mice and this strain is a valuable tool for studies of experimental optic neuropathies.

NOVEL PATIENT POSITIONING APPARATUS FOR RETINAL SURGERY IN A CASE OF SEVERE KYPHOSIS.

PURPOSE: To describe a novel patient positioning apparatus for intraocular surgery capable of accommodating patients with thoracic kyphosis. METHODS: Case report. RESULTS: A 60-year-old man presented with a macula-off retinal detachment and severe ankylosing spondylitis. The patient was scheduled for combined pars plana vitrectomy and scleral buckle. Because of the patient's severe kyphosis, a custom-designed positioning apparatus was built. The setup involved a canvas with 10 sewn-on straps and a Skytron operating table with strap inserts. Padding and blankets were also used to secure the patient comfortably in the Trendelenburg position. Surgery was uncomplicated and retinal detachment repair was successfully performed. CONCLUSION: To the authors' knowledge, this is the first report detailing a vest-like support apparatus for patients with thoracic kyphosis used in vitreoretinal surgery. This apparatus can be prepared using any conventional operating table, and it offers an effective approach to intraocular surgery for patients who cannot lie flat.

Outcome of Wilms tumor patients with bone metastasis enrolled on National Wilms Tumor Studies 1-5: A report from the Children's Oncology Group.

BACKGROUND: Wilms tumor (WT) is the most common renal tumor in children. We describe the outcomes for patients with WT that metastasized to bone (WTBM) to assist in decision making for these uncommon patients. PROCEDURE: We retrospectively reviewed the research records of patients identified with WTBM from the National Wilms Tumor Study (NWTS 1-5) database. We then related overall survival (OS) to histology, chemotherapy, radiation therapy to bone, location of metastasis, and when bone metastasis presented. RESULTS: Thirty-eight of 8609 patients enrolled on NWTS 1-5 (0.44%) developed bone metastasis. Bone metastasis most commonly first occurred at progression or relapse (29/38, 76%). Five of thirty-eight survived (13%) with the 5-year OS following presentation of bone metastasis of 14.3% (95% CI: 2.7-25.8%). The primary cause of death was tumor (29/33, 88%). Of those who died, the median survival time was 10.9 months (range 0.49-61.4). Four of nine (44%) patients presenting at diagnosis and 3% (1/29) of patients presenting in progression or relapse survived (P = 0.0075). Nineteen percent (5/26) of patients with favorable histology and 0% (0/12) with anaplastic histology survived (P = 0.16). Of the five survivors, median follow-up was 14 years (range 6.7-23.8). Radiation to metastatic bone sites was recorded in three of five survivors. No consistent chemotherapeutic approach appeared to be associated with disease outcome. CONCLUSION: Bone metastasis is rare in patients with WT, occurring more commonly in progression or relapse than at initial diagnosis. Patients with WTBM have poor prognosis. We could not identify a consistent chemotherapeutic strategy associated with survival.

Inner, outer, and full-thickness retinal folds after rhegmatogenous retinal detachment repair: A review.

Partial-thickness folds of the inner retina and outer retina, as well as full-thickness retinal folds, may occur after the repair of rhegmatogenous retinal detachment. Although these can look similar on clinical examination, imaging with optical coherence tomography facilitates differentiation. With optical coherence tomography analysis, inner retinal folds exhibit corrugations of the inner retina while outer retinal folds display hyperreflective lesions located just above the retinal pigment epithelium that may extend into the outer nuclear layer. In the case of a classic full-thickness retinal fold, all layers of the neurosensory retina may separate together from the retinal pigment epithelium with retinal reduplication and base-to-base photoreceptor orientation. We review the pathogenesis, risk factors, prevention, and management options of retinal folds. As the terminology for retinal folds is diverse, we highlight optical coherence tomography-based descriptions for retinal folds that have been used in the literature. Factors predicting visual recovery, mechanisms of spontaneous fold regression, and the effect of internal limiting membrane peeling on the incidence of folds are potential areas of future study.

A pilot study examining the effects of consuming a high-protein vs normal-protein breakfast on free-living glycemic control in overweight/obese 'breakfast skipping' adolescents.

To examine whether the daily consumption of normal-protein (NP) vs higher-protein (HP) breakfasts improve free-living glycemic control in overweight/obese, 'breakfast skipping' adolescents. Twenty-eight healthy, but overweight, teens (age: 19±1 year; BMI: 29.9±0.8 kg m(-2)) completed a 12-week randomized parallel-arm study in which the adolescents consumed either a 350 kcal NP breakfast (13 g protein) or HP breakfast (35 g protein). Pre- and post-study 24-h blood glucose measures were assessed using continuous glucose monitoring. Although no main effects of time or group were detected, time by group interactions were observed. Post hoc pairwise comparisons assessing the post-pre changes revealed that the daily consumption of the HP breakfasts tended to reduce the 24-h glucose variability (s.d.) vs NP (-0.17±0.09 vs +0.09±0.10 s.d.; P=0.06) and tended to reduce the time spent above the high glucose limit (-292±118 vs -24±80 min; P=0.09). The consumption of the HP breakfasts also reduced the 24-h maximal (peak) glucose response (-0.94±0.36 vs +0.30±0.18 mmol l(-1); P<0.01) and reduced postprandial glucose fluctuations (-0.88±0.44 vs +0.49±0.34 mmol l(-1); P<0.03) vs NP. These data suggest that the daily addition of a HP breakfast, containing 35 g of high-quality protein, has better efficacy at improving free-living glycemic control compared with a NP breakfast in overweight/obese, but otherwise healthy, 'breakfast skipping' adolescents.

First Report of Boxwood Blight Caused by Cylindrocladium pseudonaviculatum in the United States.

In September and October 2011, a new disease was observed on Buxus spp. in North Carolina and Connecticut, respectively. In North Carolina, over 10,000 containerized Buxus sempervirens (American boxwood) were affected at one location. A few weeks later, the disease was found in Connecticut on entire plantings of B. sempervirens 'Suffruticosa' (English boxwood) at two residential properties, and shortly thereafter on over 150,000 plants at two production nurseries. Initial foliar symptoms appeared as light to dark brown spots, often with dark borders. Spots enlarged and coalesced, often with a concentric pattern, and black streaks or cankers developed on stems. Infected leaves became brown or straw colored and dropped quickly after foliar symptoms were visible. Branch dieback and plant death were also observed in Connecticut. Cultures were isolated from symptomatic leaves and stems and identified as Cylindrocladium pseudonaviculatum Crous, Groenewald & Hill 2002 (1) (syn. Cylindrocladium buxicola Henricot 2002 [2]) on the basis of morphological characteristics. Macroconidiophores were single or in groups of up to three and comprised a stipe, stipe extension, and a penicillate arrangement of fertile branches. The stipe extension was septate, hyaline (89 to 170 × 2 to 4.5 µm), and terminated in an ellipsoidal vesicle (6 to 11 µm diameter) with a papillate or pointed apex. Conidia were cylindrical, straight, hyaline, and one septate (48 to 62 × 4 to 6 µm), occurring in slimy clusters. No microconidiophores were observed. Chlamydospores were medium to dark brown, thick walled, and smooth to rough. Microsclerotia were observed on PDA (1). A portion of ß-tubulin gene sequence from two Connecticut (Genbank Accession Nos. JQ866628 and JQ866629) and two North Carolina isolates showed 100% similarity with only C. pseudonaviculatum strains. USDA-APHIS-PPQ confirmed this new United States record on October 24, 2011. Pathogenicity was confirmed by inoculating three 1-gallon container plants of B. sempervirens 'Suffruticosa' in North Carolina and four liners of B. sinica var. insularis × B. sempervirens 'Green Velvet' in Connecticut with a spore suspension of approximately 5.0 × 106 conidia (North Carolina) or 1.0 × 106 conidia (Connecticut) on the foliage of each plant; untreated control plants were sprayed with water. After incubation at ambient temperature, all inoculated plants developed foliar and stem lesions within 3 to 4 days and blighting occurred within 2 weeks; control plants remained asymptomatic. C. pseudonaviculatum was reisolated from inoculated plants. To our knowledge, this is the first report of C. pseudonaviculatum in the United States. C. pseudonaviculatum causes a serious disease of Buxus spp. in the United Kingdom and several other European countries as well as New Zealand (1). Confirmation of boxwood blight in the United States is significant because of the popularity of boxwood as a landscape plant, and because of the potential economic impact this disease may have on commercial growers; boxwood production in the United States has an annual wholesale market value of approximately $103 million (3). References: (1) P. Crous, et al. Sydowia 54:23, 2002. (2) B. Henricot and A. Culham Mycologia 94: 980, 2002. (3) USDA-NASS, Census of Horticulture, 2010.

First Report of Cylindrocladium pseudonaviculatum Causing Leaf Spot of Pachysandra terminalis.

Cylindrocladium pseudonaviculatum Crous, J.Z., Groenew. & C.F. Hill 2002 was recently reported infecting common boxwood, Buxus sempervirens L., in Connecticut (2). We isolated the pathogen from leaf and stem lesions of B. sempervirens and obtained single-spored cultures on half-strength potato dextrose agar (½PDA). The pathogen was identified as C. pseudonaviculatum by morphological characteristics (1). Colony size reached 71 mm in diameter after 14 days at room temperature on ½PDA, and was fluffy with white aerial hyphae, mars brown, and reverse color chestnut brown at the center fading to pale brown forming concentric bands. Macroconidiophores were solitary or in a group of up to three, comprised a stipe, a sterile elongation, and one to three penicillate fertile branches. The stipe was up to nine septate, 90 to 250 µm long, colorless, smooth, terminating in a naviculate or broadly ellipsoidal vesicle with a pointed or papillate apex, and 27 to 50 × 6.5 to 9 µm. Primary branches were zero- to one-septate, 20 to 36 × 4 to 5 µm; secondary branches were aseptate and 11 to 20 × 3 to 4.5 µm; tertiary branches were rare, each terminal branch producing two to five phialides; phialides were doliiform or reniform, colorless, 12 to 18 µm. Conidia were cylindrical, rounded at both ends, straight, smooth, colorless, two-celled, 48 to 55 × 4.5 to 5.5 µm, and in colorless slimy cylindrical clusters. Microconidiophores were not observed. Chlamydospores were golden to dark brown, thick-walled, and smooth or rough. Microsclerotia were present on ½PDA. Primers T1 and T22 (3) were used to amplify a portion of the ß-tubulin gene from isolates Cps-CT-L1 and Cps-CT-S1. Amplified sequences were used in a BLAST search against the GenBank database to demonstrate 100% sequence identity only with other C. pseudonaviculatum strains. Both sequences were deposited in GenBank (Accession Nos. JQ866628 and JQ866629), using corresponding gene data from C. pseudonaviculatum strain STE-U 3399 (GenBank Accession No. AF449455) to distinguish coding from noncoding regions. Healthy plants of Japanese spurge, Pachysandra terminalis, with three plants per 10 cm diameter pot, were inoculated with water alone or a conidial suspension of C. pseudonaviculatum isolate Cps-CT-L1 (ATCC MYA-4891) (1.0 × 106 conidia/plant) with a handheld sprayer until runoff. Plants were kept moist in a plastic bag for 48 h at laboratory temperature and then transferred to the greenhouse. Circular lesions (1- to 4-mm diameter) were evident on leaves after 10 days. All 12 inoculated plants developed lesions, and no lesions were observed on noninoculated plants. Leaves with lesions were surface sterilized in 0.5% NaOCl for 30 s, rinsed twice in sterile water, and lesion margins plated onto water agar or ½PDA. The pathogen was reisolated from at least one leaf per plant. Koch's postulates were performed again with isolate Cps-CT-S1 (ATCC MYA-4890). After 3 weeks, many of the leaves with lesions yellowed and dropped to the soil surface and heavy sporulation of C. pseudonaviculatum and microsclerotia were observed. To our knowledge, this is the first report of C. pseudonaviculatum causing a leaf spot disease on P. terminalis. Pachysandra is a widely grown ground cover suitable for shady, humid environmental conditions that may be conducive for the development of disease. References: (1) P. Crous, et al. Sydowia 54:23, 2002. (2) K. Ivors et al. Plant Disease. 96:X, 2012. (3) K. O'Donnell and E. Cigelnik Mol. Phylogenet. Evol. 7:103, 1997.

Preparation for a medical mission to Jamaica--pharmacy's perspective.

OBJECTIVE: To describe preparation of a medical mission from a pharmacy team's perspective. METHODS: Essential components of the medication planning process include the development of a separate medication budget, a medication formulary (based on needs assessment and availability) and acquisition of medications and medical supplies. RESULTS: For the medical mission to Jamaica, medications are often purchased or donated from various locations, including retail pharmacies, drug wholesalers, medication drives, pharmaceutical companies, and medication assistance programmes specific to medical missions. It is essential to understand the policy associated with the importation of medications which can be found in the Approval Process for Food, Drugs, Cosmetics, Medical devices, Precursor Chemicals and Narcotics, a paper developed by the Ministry of Health, Jamaica. CONCLUSIONS: Elevated levels of planning and preparation are required for the medical mission to Jamaica to be a success; assistance and cooperation is necessary from all members of the interdisciplinary medical mission team. It is imperative to plan ahead, be organized and equipped to handle unexpected situations so that quality care can be delivered to the patients to be served.

First Report of Uromyces acuminatus on Honckenya peploides, the Endangered Seabeach Sandwort.

Honckenya peploides (L.) Ehrh. (Caryophyllaceae), commonly known as seabeach sandwort, is a species of special concern in Connecticut (4). Nearly an entire population of H. peploides in New London County, CT was found to be severely infected by the aecial stage of a rust fungus in June of 2008. Representative plants in the population were infected with aecia on more than 50% of the leaves. Aecia were amphigenous, gregarious, cupulate, pulverulent, yellowish, and erumpent with a hyaline to whitish peridium having a lacerate, somewhat recurved margin. Peridial cells were rhomboidal, 26 to 31 × 25 to 29 µm, smooth to finely verrucose. Aeciospores were globose to ellipsoid, 23.5 to 29 × 20.5 to 22 µm, hyaline to pale yellowish with a verrucose surface and hyaline walls 1.5 to 2 µm thick. Morphological characters corresponded to a reference specimen (BPI 000105) of the aecial stage of Uromyces acuminatus Arthur from Nova Scotia, as well as published descriptions (1,2). Subsequently, telia of U. acuminatus were discovered on Spartina patens (Aiton) Muhl. (Poaceae) in May of 2009 in New London County, CT. Telia were adaxial, intercostal, scattered to gregarious, linear and at times elongate, dark brown to black, pulverulent, and erumpent. Teliospores were obovate to ellipsoid with rounded to acuminate apices rarely having two points, 30 to 41 × 19 to 24 µm, with a smooth surface and brownish-yellow to brown walls 9 to 14 µm thick at apex, which is sometimes paler, and 1 to 3 µm thick laterally, pedicels with a portion persisting on the teliospore that is up to 82 µm long and brownish-yellow. The ITS2 and 5' region of the 28S rDNA (998 bp) from the rust on H. peploides (GenBank Accession No. GU109282, BPI 879300) and the rust on S. patens (GenBank Accession No. GU058008, BPI 879285B) were sequenced to confirm the identification of U. acuminatus on H. peploides with the resulting sequences identical. U. acuminatus is widespread in the eastern United States and Canada (1-3). The telial stage is found on Spartina spp., while the aecial stage is found on numerous taxa including members of the Asparagaceae (formerly Ruscaceae, Liliaceae), Caryophyllaceae, Polemoniaceae, and Primulaceae (1-3). Puccinia arenariae (Schumach.) G. Winter, previously reported from H. peploides (4), is microcyclic and stages 0, I, and II are unknown. To our knowledge, this is the first report of U. acuminatus on the genus Honckenya. This report has significance to natural resource conservation managers and scientists working in endangered plant habitats because H. peploides and H. peploides subsp. robusta are listed as plants of special concern or endangered/extirpated in Connecticut, Maryland, New Hampshire, and Rhode Island (4). References: (1) J. C. Arthur. Order Uredinales. N. Am. Flora 7(3):161, 1912. (2) G. B. Cummins. The Rust Fungi of Cereals, Grasses and Bamboos. Springer-Verlag, New York, 1971. (3) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Mycology and Microbiology Laboratory. Online publication. ARS, USDA, 2009. (4) USDA, NRCS. The PLANTS Database. Online publication. National Plant Data Center, Baton Rouge, LA, 2009.

Sensitivity of Botrytis cinerea from Connecticut Greenhouses to Benzimidazole and Dicarboximide Fungicides.

Botrytis cinerea was isolated from infected plants in six greenhouses in Connecticut. Forty-five isolates were evaluated in vitro to determine fungicide sensitivity to benzimidazole (benomyl and thiophanate-methyl) and dicarboximide fungicides (vinclozolin and iprodione). B. cinerea isolates with fungicide resistance were recovered from each greenhouse sampled. Benzimida-zole resistance was more common than dicarboximide resistance (74 to 76% versus 36 to 43%, respectively). Multiple fungicide resistance was common. Nineteen isolates were resistant to both a benzimidazole and a dicarboximide fungicide. The level (EC50) of resistance to dicer-boximides was low compared with resistance to benzimidazoles. Isolate growth rate was not correlated to fungicide sensitivity or EC50. Fungicide resistance was apparently unrelated to the patterns of fungicide use in greenhouses sampled.

First Report of Powdery Mildew of Tomato Caused by an Erysiphe sp. in Connecticut.

In 1995 and 1996, powdery mildew was observed on several samples of field-grown tomato foliage (Lycopersicon esculentum Mill.; various cultivars) submitted to the CAES Plant Disease and Information Office. Symptoms included gray superficial mycelium with abundant sporulation on adaxial and abaxial leaf surfaces, followed in the field by dessication of the foliage and rapid defoliation. No cleistothecia were observed, and single-celled, hyaline, ellipsoidal conidia occurred, usually singly, on unbranched conidiophores. Pyriform conidia occurred at a frequency of less than 1%. Conidia ranged in length from 25.6 to 43.2 µm (mean = 33.6, SE = 0.4) and in width from 13.1 to 23.1 µm (mean = 18.2, SE = 0.2; n = 500). Fibrosin bodies were not observed, and vacuoles were present. Based on conidial characteristics, the fungus was identified as an unknown Erysiphe sp. To confirm pathogenicity, 2-week-old tomato seedlings (cv. Rutgers) were inoculated by shaking dry conidia onto the leaves and placed within plastic tents on a greenhouse bench. Control plants were treated identically but not inoculated. The inoculated plants developed foliar powdery mildew symptoms, and sporulation was observed. Susceptible cultivars that were naturally infected included Better Boy, Better Beef, Celebrity, Rutgers, Ultra Magnum, Ultra Sweet, Whopper, Yellow Brandywine; cherry type tomatoes Matts Wild Cherry and Sweet Chelsea; and plum type tomatoes Roma and Super San Marzano. Eastern black nightshade (Solanum ptycanthum Dunal), eggplant (S. melongena L. 'Black Pride'), and tobacco (Nicotiana tabacum L. 'C9') were also naturally infected under greenhouse conditions. However, conidia size and number of conidia per conidiophore differed between hosts. Conidia from tobacco, eggplant, and nightshade averaged 37.8 × 19.1 µm (SE = 0.5 and 0.2, respectively) with a 95% CI of 35.5 to 40.0 × 18.1 to 20.3 µm (n = 300). Conidia from tomato were smaller, averaging 33.6 × 18.2 µm (SE = 0.3 and 0.2, respectively) with a 95% CI of 32.7 to 34.4 × 17.5 to 18.9 µm (n = 300). Factorial inoculation experiments between tomato and other hosts demonstrated cross-infectivity, but isolates originally from tobacco had significantly larger conidia when infecting tomato than isolates originally from tomato infecting tobacco. Powdery mildew isolates on tomato had fewer (P = 0.001) conidia per conidiophore (mean = 1.39, range = 1 to 4) than isolates infecting tobacco inoculated at the same time and held under the same conditions (mean = 2.54, range = 1 to 6). These results demonstrate considerable morphological variation in the powdery mildew fungus, perhaps associated with hosts such as tomato or other solanaceous plants. This is the first report of powdery mildew of tomato and tobacco in Connecticut. Powdery mildew of tomato has been reported to occur in the field in California, and in greenhouse tomatoes in New York (2). Powdery mildew of tobacco has only been reported on artificially inoculated plants in California (1). References: (1) C. R. Arredondo et al. Plant Dis. 80:1303, 1996. (2) D. M. Karasevicz and T. A. Zitter. Plant Dis. 80:709, 1996.

Maternal depression, assessment methods, and physical symptoms affect estimates of depressive symptomatology among children with cancer.

Investigated the incidence of depressive symptoms and their covariates in a sample of 99 children undergoing treatment for cancer and their mothers. Although the prevalence of depressive symptoms falling within the clinical range was low (7 to 8%), classification of these children was highly dependent upon the informant and instrument used. Interrater reliabilities did not differ from chance levels. Separate multiple regression analyses of the mother's and nurse's ratings of the child's level of depression, the child's self-report on the Child Depression Inventory, and the mother's responses to the Child Behavior Checklist depression scales revealed different statistical models for each method of assessment. However, increased severity of the mother's self-report of depressive symptoms on the Beck Depression Inventory, which was predicted by low perceived social support and hospitalization of her child, was associated with higher levels of child depression on all child- and parent-report measures. Parental adjustment, sociodemographic, and medical factors as well as methods of assessment must be addressed by models explaining the etiology of depressive symptoms among pediatric oncology patients.

Amiloride-sensitive sodium-hydrogen exchange in osmotically shrunken rabbit red blood cells.

As part of a detailed study of cell volume regulation in high-potassium mammalian erythrocytes, we have characterized ouabain-insensitive sodium transport in normal and osmotically shrunken rabbit red cells. In cells of normal volume and physiological pH, there is no amiloride-inhibited component of the sodium efflux (into either sodium-containing or sodium-free media). Osmotic shrinkage activates an amiloride-sensitive (50% inhibitory concentration = 10(-5) M) sodium transport system that can catalyze net sodium movement in either direction. This system appears to be distinct from the sodium-sodium (sodium-lithium) counter-transporter that operates in cells of normal volume. Replacement of chloride with acetate does not inhibit the sodium flux, but replacement with either nitrate or thiocyanate is inhibitory. An inward sodium gradient in shrunken cells induces a net uphill efflux of acid equivalents, indicating that the sodium transport is a sodium-hydrogen exchange. However, a sevenfold inward gradient of hydrogen ions (pHo = 6.4; pHi = 7.2) does not stimulate net sodium efflux in shrunken cells. This suggests that the extracellular affinity of the transport site for hydrogen ions is high, and that there is an extracellular noncompetitive inhibitory site for proton binding. Bilateral pH reduction stimulates an amiloride-inhibitable sodium flux in cells of normal volume; this indicates that, as has been found in kidney, brain, and lymphocytes, there is an intracellular protonation site that can activate the transport. Shrinkage of the cells shifts the pH dependence of the transport, suggesting that part of the signal for the osmotic activation of the transport is a shift in the pKa of this modifier site.

Functions of extracellular lysine residues in the human erythrocyte anion transport protein.

The extracellular lysine residues in the human erythrocyte anion transport protein (band 3) have been investigated using chemical modification with the impermeant homobifunctional active ester bis(sulfosuccinimidyl)-suberate (BSSS). This agent forms covalent intra- and intermolecular cross-links in human band 3 in intact cells (Staros and Kakkad. 1983. J. Membr. Biol. 74:247). We have found that the intermolecular cross-link has no detectable effect on the anion transport function of band 3. The intramolecular cross-link, however, causes major changes in the characteristics of the anion transport. These functional alterations are caused by the modification of lysine residues at the stilbene disulfonate binding site. BSSS pretreatment at pH 7.4 irreversibly inhibits Cl-Br exchange by at least 90% when the transport is assayed at extracellular pH above 8. In the same BSSS-pretreated cells, however, the Cl-Br exchange rate is activated by lowering the pH of the flux medium (intracellular pH fixed at 7). The flux is maximal at pH 5-6; a further lowering of the extracellular pH inhibits the anion exchange. This acid-activated Cl-Br exchange in the BSSS-treated cells is mediated by band 3, as indicated by phenylglyoxal and phloretin inhibition of the flux. Thus, the BSSS pretreatment has little effect on the maximal Cl-Br exchange flux catalyzed by band 3, but it shifts the alkaline branch of its extracellular pH dependence by approximately 5 pH units. BSSS also eliminates the self-inhibition of Cl-halide exchange by high extracellular Br or I concentrations. These results indicate that the BSSS-modified lysines do not participate directly in anion translocation, but that one of the lysines normally provides a positive charge that is necessary for substrate anion binding. This positive charge is removed by the BSSS treatment but can be replaced by lowering the extracellular pH. The results also provide insight regarding the halide selectivity of the maximal rate of chloride-halide exchange: the native selectivity (Br much greater than I) is nearly abolished by BSSS treatment, which suggests that the selectivity results from the very strong binding of iodide to an outward-facing modifier site.