Corneal Culture and Antibiotic Susceptibility Results for Microbial Keratitis in the Mid-Atlantic Region of the United States, 2016 to 2020.

OBJECTIVE: To examine the microbial distribution and antimicrobial susceptibility of culture-positive microbial keratitis at a large tertiary referral center in the mid-Atlantic region of the United States. METHODS: Retrospective review of culture-positive microbial keratitis cases at the Wilmer Eye Institute from 2016 through 2020. RESULTS: Of the 474 culture-positive microbial keratitis cases, most were bacterial (N=450, 94.9%), followed by fungal (N=48, 10.1%) and Acanthamoeba keratitis (N=15, 3.1%). Of the 450 bacterial isolates, 284 (69.5%) were gram-positive organisms, whereas 157 (28.4%) were gram-negative organisms. The most common bacterial species isolated was coagulase-negative Staphylococcus spp (N=154, 24.8%), and the most common gram-negative isolate was Pseudomonas aeruginosa (N=76, 12.3%). Among fungi, the most common isolates were Candida (N=25, 45.4%), whereas Fusarium (N=6, 10.9%) and Aspergillus (N=3, 5.5%) were less common. Of the 217 bacterial isolates tested for erythromycin susceptibility, 121 (55.7%; ∼60% of coagulase-negative staphylococci and corynebacteria tested) showed resistance to erythromycin. CONCLUSIONS: Microbial keratitis in the Baltimore Mid-Atlantic region of the United States is most commonly caused by bacteria, with fungi and acanthamoeba being less common. Gram-positive bacterial infections predominate. Among fungal keratitis cases, Candida species are more commonly encountered than are filamentous species. Use of erythromycin as infection prophylaxis should be reexamined. Findings from our study may guide empiric treatment in this geographic region.

Retrobulbar respiratory epithelial orbital cyst in a dog: A case report.

A 10-month-old female, neutered French Bulldog presented with a history of unilateral right-sided intermittent conjunctivitis and exophthalmos. The patient suffered blunt force trauma to the right eye after a tennis ball impact approximately five months prior to presentation. Examination identified the patient was visual with exophthalmos, lateral strabismus, conjunctival hyperaemia, episcleral congestion, and papilloedema. Magnetic resonance imaging and ultrasonography identified an approximately two centimeter diameter fluid-filled structure directly posterior to the globe leading to displacement of the optic nerve and distortion of the posterior globe wall. Centesis of the lesion demonstrated neutrophilic and macrophagic inflammation with evidence of prior hemorrhage. Within four weeks, the structure had re-filled to its original size and was subsequently excised in its entirety, via a lateral orbitotomy. Histopathologic findings indicated a non-keratinising orbital cyst, the lining of which was consistent with a respiratory epithelial cyst. Recurrence had not occurred seven months' post-surgery. To the author's knowledge, previous reports of retrobulbar respiratory epithelial cysts have not been documented in animals.

Sustainability capacity of a vegetable gardening intervention for cancer survivors.

BACKGROUND: Health behavior interventions, especially those that promote improved diet and physical activity, are increasingly directed toward cancer survivors given their burgeoning numbers and high risk for comorbidity and functional decline. However, for health behavior interventions to achieve maximal public health impact, sustainability at both the individual and organizational levels is crucial. The current study aimed to assess the individual and organizational sustainability of the Harvest for Health mentored vegetable gardening intervention among cancer survivors. METHODS: Telephone surveys were conducted among 100 cancer survivors (mean age 63 years; primarily breast cancer) completing one-of-two Harvest for Health feasibility trials. Surveys ascertained whether participants continued gardening, and if so, whether they had expanded their gardens. Additionally, surveys were emailed to 23 stakeholders (Cooperative Extension county agents, cancer support group leaders, and healthcare representatives) who were asked to rate the intervention's ability to generate sustained service and produce benefits over time using the eight-domain Program Sustainability Assessment Tool (PSAT). RESULTS: The survey among cancer survivors (91.9% response rate) indicated that 85.7% continued gardening throughout the 12 months following intervention completion; 47.3% expanded their gardens beyond the space of the original intervention. Moreover, 5.5% of cancer survivors enrolled in the certification program to become Extension Master Gardeners. The survey among stakeholders generated a similar response rate (i.e., 91.3%) and favorable scores. Of the possible maximum of 7 points on the PSAT, the gardening intervention's "Overall Capacity for Sustainability" scored 5.7 (81.4% of the maximum score), with subscales for "Funding Stability" scoring the lowest though still favorably (5.0) and "Program Evaluation" scoring the highest (6.3). CONCLUSIONS: Data support the sustainability capacity of the Harvest for Health vegetable gardening intervention for cancer survivors. Indeed, few interventions have proven as durable in terms of individual sustainability. Furthermore, Harvest for Health's overall organizational score of 5.7 on the PSAT is considered strong when compared to a previous review of over 250 programs, where the mean overall organizational PSAT score was 4.84. Thus, solutions for long-term funding are currently being explored to support this strong, holistic program that is directed toward this vulnerable and growing population. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02150148.

The diagnostic yield of advanced imaging in dogs with Horner's syndrome presenting with and without additional clinical signs: A retrospective study of 120 cases (2000-2018).

PURPOSE: To evaluate the diagnostic yield of advanced imaging in dogs with Horner's syndrome (HS) both with and without additional clinical signs. METHODS: Retrospective review of clinical records from a UK referral hospital (2000-2018). Cases were excluded if HS was trauma- or surgery-related and if no advanced imaging with MRI or CT was performed. Imaging findings were assessed as well as any additional investigations performed. RESULTS: One hundred twenty cases met the inclusion criteria; 88 with additional clinical signs and 32 with isolated HS. MRI or CT of head and neck was performed in 115 cases and/or thoracic CT in eight cases. Causative lesions were identified in 98% (86/88) of cases with additional clinical signs and 3% (1/32) of cases with isolated HS. This was statistically significant (p < .001). Pharmacological localization using phenylephrine (0.1%-10%) was accurate in predicting the site of a causative lesion in 79% (19/24) of tested cases. Overall, 28% (33/120) of cases were idiopathic, of which 49% (16/33) were golden retrievers. When compared to the overall hospital population, and UK Kennel Club records, this confirmed a significant predisposition in this breed (p < .001). No associations between idiopathic HS and concurrent systemic disease were identified. CONCLUSION: This is the first study to evaluate the diagnostic yield of advanced imaging in dogs with HS. Isolated HS is significantly more likely to be idiopathic than cases presenting with additional clinical signs; this could guide decision-making regarding further investigations performed in a clinical setting. Idiopathic HS is over-represented in the golden retriever.

Melting corneal ulcers (keratomalacia) in dogs: A 5-year clinical and microbiological study (2014-2018).

OBJECTIVES: To identify bacterial microorganisms associated with canine keratomalacia, review their antimicrobial sensitivity, and evaluate clinical outcomes compared to results of microbial culture. METHODS: Retrospective analysis of clinical records of dogs diagnosed with a melting corneal ulcer presented to a referral hospital in Hertfordshire, UK between 2014 and 2018. RESULTS: One hundred and ten melting corneal ulcers were sampled in 106 dogs. The most common pure bacterial isolate was Pseudomonas aeruginosa (n = 26) followed by ß-hemolytic Streptococcus (n = 12). Melting corneal ulcers that cultured coagulase-positive Staphylococcus, coliform bacteria, Pasteurella multocida, Enterococcus, and Streptococcus viridans presented in smaller numbers and were analyzed together (n = 16). Multiple cultures were identified in nine cases (n = 9). Forty-seven cultures yielded no bacterial growth (n = 47). The susceptibility to fluoroquinolones remained high with the exception of ß-hemolytic Streptococci. There was no significant difference in the ulcer severity at presentation in regard to the cultured bacteria. Overall, 63 eyes (57%) received surgical grafting in addition to medical treatment. In 14 cases (13%), the progression of corneal melting despite medical ± surgical treatment resulted in enucleation. Fifty-seven percent (8/14) of the enucleated eyes cultured pure Pseudomonas aeruginosa isolates. In contrast, all ß-hemolytic Streptococcus-associated ulcers healed. CONCLUSIONS: The most common bacterial species associated with canine keratomalacia were Pseudomonas aeruginosa and ß-hemolytic Streptococcus. Because of the variation in antibacterial sensitivity between these two species, bacterial culture and sensitivity testing should be performed in all dogs presenting with keratomalacia. Melting corneal ulcers associated with pure Pseudomonas infection were significantly more likely to result in globe loss than melting corneal ulcers associated with other cultures.

Building Capacity in Health Professionals to Conduct Quality Improvement: Evaluation From a Collaborative Interorganizational Program.

BACKGROUND: The Toronto Academic Health Sciences Network Health Professions Innovation Fellowship Program began in 2014 as a pilot initiative among 4 academic teaching hospitals in Toronto, Ontario. The purpose of the Program was to cultivate applied leadership, interprofessional collaboration, and quality improvement capacity among health professionals. PURPOSE: This article reports on the evaluation findings from the initial year as well as an update on current program status and sustainability. METHODS: A formative evaluation was conducted focused on the impact on clinical practice, participant skill development, participant experience, and cross-organizational partnerships. Data were collected through a focus group, interviews, and pre- and postsurveys. RESULTS: Data from the initial pilot showed increases in leadership practices, project management, and quality improvement knowledge, with changes in leadership practices being significant. Positive changes in clinical practice at both the individual and unit/team levels and capacity for building relationships were also reported. Since the pilot, more than 160 participants from 15 health professions and 9 organizations have participated. Several graduates have taken on leadership roles since their participation in the Program. CONCLUSIONS: Health care organizations wishing to advance academic practice may benefit from implementing a similar collaborative program to reap benefits beyond organizational silos.

Outcome of phacoemulsification in 71 cats: A multicenter retrospective study (2006-2017).

PURPOSE: To assess outcome of phacoemulsification in cats. METHODS: Records of 71 cats (82 eyes) from five referral centers were reviewed. Groups were divided by cause of cataract (congenital/juvenile [n = 32], traumatic [n = 33], and secondary to uveitis [n = 6]), and group comparisons were performed for the most common complications: postoperative ocular hypertension (POH), uveitis, corneal ulceration, synechia/dyscoria, and posterior capsular opacity (PCO) in three different time periods: immediately postoperatively, at 1-90 days, and at >90 days. RESULTS: Median follow-up was 198 days (interquartile range 64-518 days). The overall visual success rate of the cats with a 12-month follow-up was 92.6% (25/27 eyes). POH occurred in 35/82 (42.6%) eyes. Immediately postoperatively, uveitis was the most common complication in 28/82 eyes (34.1%) followed by corneal ulceration in 22/82 eyes (26.8%). At 1-90 days, uveitis in 41/81 eyes (50.6%) remained the most common complication, followed by synechia/dyscoria in 21/81 eyes (25.9%), corneal ulceration in 16/81 eyes (19.7%), and PCO in 15/81 eyes (18.5%). At >90 days, PCO in 17/47 eyes (36.1%), followed by synechia/dyscoria in 16/47 eyes (34%), was the most common complications. The number of eyes with synechia/dyscoria in the trauma group was higher (13/33 [39.3%]) than in the congenital/juvenile group (5/31 [16.1%]) at 1-90 days (P = .039). No statistical difference was found for the other group comparisons. Three eyes in total were enucleated owing to endophthalmitis, post-traumatic ocular sarcoma, and secondary glaucoma. CONCLUSION: Uveitis in the short-term and PCO and synechia/dyscoria in the long-term were the most common complications following phacoemulsification in cats.

A home-based mentored vegetable gardening intervention demonstrates feasibility and improvements in physical activity and performance among breast cancer survivors.

BACKGROUND: The current study assessed the feasibility of a mentored home-based vegetable gardening intervention and examined changes in health-related outcomes among breast cancer survivors (BCS). METHODS: BCS were randomized to either a year-long vegetable gardening intervention to begin immediately or a wait-list control. Master Gardeners mentored participants in planning, planting, and maintaining 3 seasonal gardens over the course of 1 year. Participant accrual, retention, and satisfaction rates of ≥80% served as feasibility (primary outcome) benchmarks. Secondary outcomes (ie, vegetable consumption, physical activity, performance and function, anthropometrics, biomarkers, and health-related quality of life) were collected at baseline and post-intervention (1-year follow-up) using subjective and objective measures. RESULTS: The trial surpassed all feasibility benchmarks at 82% of targeted accrual, 95% retention, and 100% satisfaction (ie, experience ratings of "good to excellent" and willingness to "do it again"). Compared with the controls, intervention participants reported significantly greater improvements in moderate physical activity (+14 vs -17 minutes/week) and demonstrated improvements in the 2-Minute Step Test (+22 vs + 10 steps), and Arm Curl (+2.7 vs + 0.1 repetitions) (P values < .05). A trend toward improved vegetable consumption was observed (+0.9 vs + 0.2 servings/day; P = .06). Approximately 86% of participants were continuing to garden at the 2-year follow-up. CONCLUSIONS: The results of the current study suggest that a mentored, home-based vegetable gardening intervention is feasible and offers an integrative and durable approach with which to improve health behaviors and outcomes among BCS. Harvest for Health led to the establishment of a group of trained Master Gardeners and gave rise to local and global community-based programs. Larger studies are needed to confirm the results presented herein and to define applicability across broader populations of survivors.

Inherent Resistance to 14α-Demethylation Inhibitor Fungicides in Colletotrichum truncatum Is Likely Linked to CYP51A and/or CYP51B Gene Variants.

Anthracnose disease, caused by Colletotrichum truncatum, affects marketable yield during preharvest production and postharvest storage of fruits and vegetables worldwide. Demethylation inhibitor (DMI) fungicides are among the very few chemical classes of single-site mode of action fungicides that are effective in controlling anthracnose disease. However, some species are inherently resistant to DMIs and more information is needed to understand this phenomenon. Isolates of C. truncatum were collected from the United States and China from peach, soybean, citrus, and begonia and sensitivity to six DMIs (difenoconazole, propiconazole, metconazole, tebuconazole, flutriafol, and fenbuconazole) was determined. Compared with DMI sensitive isolates of C. fructicola, C. siamense, and C. fioriniae (EC50 value ranging from 0.03 to 16.2 µg/ml to six DMIs), C. truncatum and C. nymphaeae were resistant to flutriafol and fenbuconazole (with EC50 values of more 50 µg/ml). Moreover, C. truncatum was resistant to tebuconazole and metconazole (with resistance factors of 27.4 and 96.0) and displayed reduced sensitivity to difenoconazole and propiconazole (with resistance factors of 5.1 and 5.2). Analysis of the Colletotrichum spp. genome revealed two potential DMI targets, CYP51A and CYP51B, that putatively encode P450 sterol 14α-demethylases. Both genes were identified and sequenced from C. truncatum and other species and no correlation between CYP51 gene expression levels and fungicide sensitivity was found. Four amino acid variations L208Y, H238R, S302A, and I366L in CYP51A, and three variations H373 N, M376L, and S511T in CYP51B correlated with the DMI resistance phenotype. CYP51A structure model analysis suggested the four alterations may reduce azole affinity. Likewise, CYP51B structure analysis suggested the H373 N and M376L variants may change the conformation of the DMI binding pocket, thereby causing differential sensitivity to DMI fungicides in C. truncatum.

Factors emerging from the "Zarit Burden Interview" and predictive variables in a UK sample of caregivers for people with dementia.

ABSTRACTBackground:Caring for persons with dementia (PWD) can create "caregiver burden," which is associated with negative outcomes for caregivers and PWD. The ZBI (Zarit Burden Interview) is a widely used unitary measure of caregiver burden. However, recent research has found caregiver burden to be multi-dimensional. The purpose of this study was to explore the factor structure of the ZBI within a sample of UK caregivers. A secondary aim was to identify variables that predicted burden dimensions found. METHODS: A total of 110 unpaid community caregivers of PWD completed the ZBI. They also completed the EACQ (Experiential Avoidance in Caregiving Questionnaire), DEX (Dysexecutive Questionnaire), PACS (Positive Aspects of Caregiving Scale), and a demographic questionnaire. ZBI data were analyzed via exploratory factor analysis (principal axis factoring). Relationships between burden factors and other variables were studied using Pearson correlations and multiple regression. RESULTS: Analysis identified three burden factors, namely direct impact of caregiving, uncertainty around the future, and frustration/embarrassment. A direct impact of caregiving and frustration/embarrassment has been found previously. Uncertainty over the future is a new factor, which was predicted by adult-child caregiver role, highlighting that spouses and adult children are likely to have different burden experiences. Additionally, uncertainty over the future and frustration/embarrassment were inversely predicted by PACS, suggesting that being mindful of positive aspects of caregiving may function as a protective factor for burden. CONCLUSIONS: This study found caregiver burden to be multi-dimensional and uncovered a novel factor in uncertainty over the future, which warrants further exploration. Burden factors were associated with a range of modifiable variables that could be targeted within health and social care interventions to improve outcomes for caregivers and PWD.

Alternative acetate production pathways in Chlamydomonas reinhardtii during dark anoxia and the dominant role of chloroplasts in fermentative acetate production.

Chlamydomonas reinhardtii insertion mutants disrupted for genes encoding acetate kinases (EC 2.7.2.1) (ACK1 and ACK2) and a phosphate acetyltransferase (EC 2.3.1.8) (PAT2, but not PAT1) were isolated to characterize fermentative acetate production. ACK1 and PAT2 were localized to chloroplasts, while ACK2 and PAT1 were shown to be in mitochondria. Characterization of the mutants showed that PAT2 and ACK1 activity in chloroplasts plays a dominant role (relative to ACK2 and PAT1 in mitochondria) in producing acetate under dark, anoxic conditions and, surprisingly, also suggested that Chlamydomonas has other pathways that generate acetate in the absence of ACK activity. We identified a number of proteins associated with alternative pathways for acetate production that are encoded on the Chlamydomonas genome. Furthermore, we observed that only modest alterations in the accumulation of fermentative products occurred in the ack1, ack2, and ack1 ack2 mutants, which contrasts with the substantial metabolite alterations described in strains devoid of other key fermentation enzymes.

A randomised controlled trial of a nanofilled composite at three years: Did selective enamel etching have an effect?

General dental practice is increasingly being recognised as the ideal situation for the conduct of clinical trials into the longevity of restorations. The aim of this study was to investigate the survival of 75 nanofilled resin composite restorations placed in an assortment of cavities using a self-etch dentine bonding agent, in five UK dental practices by members of the UK-based practice-based research group, the PREP Panel, with half of the restorations receiving a selective enamel etch and the other half being placed using a self-etching approach. The results indicated good performance of the restorations examined, with no failures being identified and excellent surface characteristics, in terms of colour stability, minimal surface roughness and optimal anatomic form. Selective enamel etching tended to produce less marginal discolouration, although these results were not statistically significant.

Biochemical and Kinetic Characterization of the Eukaryotic Phosphotransacetylase Class IIa Enzyme from Phytophthora ramorum.

Phosphotransacetylase (Pta), a key enzyme in bacterial metabolism, catalyzes the reversible transfer of an acetyl group from acetyl phosphate to coenzyme A (CoA) to produce acetyl-CoA and Pi. Two classes of Pta have been identified based on the absence (Pta(I)) or presence (Pta(II)) of an N-terminal regulatory domain. Pta(I) has been fairly well studied in bacteria and one genus of archaea; however, only the Escherichia coli and Salmonella enterica Pta(II) enzymes have been biochemically characterized, and they are allosterically regulated. Here, we describe the first biochemical and kinetic characterization of a eukaryotic Pta from the oomycete Phytophthora ramorum. The two Ptas from P. ramorum, designated PrPta(II)1 and PrPta(II)2, both belong to class II. PrPta(II)1 displayed positive cooperativity for both acetyl phosphate and CoA and is allosterically regulated. We compared the effects of different metabolites on PrPta(II)1 and the S. enterica Pta(II) and found that, although the N-terminal regulatory domains share only 19% identity, both enzymes are inhibited by ATP, NADP, NADH, phosphoenolpyruvate (PEP), and pyruvate in the acetyl-CoA/Pi-forming direction but are differentially regulated by AMP. Phylogenetic analysis of bacterial, archaeal, and eukaryotic sequences identified four subtypes of Pta(II) based on the presence or absence of the P-loop and DRTGG subdomains within the N-terminal regulatory domain. Although the E. coli, S. enterica, and P. ramorum enzymes all belong to the IIa subclass, our kinetic analysis has indicated that enzymes within a subclass can still display differences in their allosteric regulation.

Survey of the incidence of pectinate ligament dysplasia and glaucoma in the UK Leonberger population.

OBJECTIVE: To determine the prevalence of pectinate ligament dysplasia (PLD) in UK Leonbergers and identify cases affected by glaucoma. Also, to define the spectrum of pectinate ligament (PL) appearance in this breed and determine whether gonioscopic monitoring should be recommended. ANIMALS STUDIED: Data were compiled from 78 prospective gonioscopy examinations performed by one author (GF) and retrospective analysis of 233 UK eye scheme certificates (2009-2014). Clinical cases of glaucoma in Leonbergers diagnosed by UK veterinary ophthalmologists, where gonioscopy of the fellow eyes or histology of affected eyes had been performed, were also reviewed. PROCEDURE: In the prospective study, intraocular pressure was recorded prior to gonioscopy using a rebound tonometer. Gonioscopy was performed using a slit-lamp biomicroscope with a Koeppe goniolens. PLD was categorized according to the percentage of the iridocorneal drainage angle affected (grade 0 = <25% affected; grade 1 = 25-50% affected; grade 2 = 51-75% affected; and grade 3 = >75% affected), and the degree of narrowing of the angle was noted. RESULTS: Of 78 dogs examined prospectively, 64/78 (82%) were grade 0, 7/78 (9%) were grade 1, 3/78 (4%) were grade 2, and 4/78 (5%) were grade 3. A large phenotypic variation was observed. Spearman's rank correlation showed a positive correlation between age and severity of PLD (P < 0.0055). 52 (22%) of Leonbergers examined under the UK eye scheme 2009-2014 were affected by PLD. Five clinical cases of glaucoma were reviewed where gonioscopy had been performed and one where histology was performed. All individuals had grade 3 PLD with gonioscopy of the contralateral eye or severe goniodysgenesis with histological sections of the affected eye. CONCLUSION: This survey suggests the prevalence of PLD is sufficient to justify ongoing screening of Leonbergers.

Allosteric regulation of Lactobacillus plantarum xylulose 5-phosphate/fructose 6-phosphate phosphoketolase (Xfp).

UNLABELLED: Xylulose 5-phosphate/fructose 6-phosphate phosphoketolase (Xfp), which catalyzes the conversion of xylulose 5-phosphate (X5P) or fructose 6-phosphate (F6P) to acetyl phosphate, plays a key role in carbohydrate metabolism in a number of bacteria. Recently, we demonstrated that the fungal Cryptococcus neoformans Xfp2 exhibits both substrate cooperativity for all substrates (X5P, F6P, and Pi) and allosteric regulation in the forms of inhibition by phosphoenolpyruvate (PEP), oxaloacetic acid (OAA), and ATP and activation by AMP (K. Glenn, C. Ingram-Smith, and K. S. Smith. Eukaryot Cell 13: 657-663, 2014). Allosteric regulation has not been reported previously for the characterized bacterial Xfps. Here, we report the discovery of substrate cooperativity and allosteric regulation among bacterial Xfps, specifically the Lactobacillus plantarum Xfp. L. plantarum Xfp is an allosteric enzyme inhibited by PEP, OAA, and glyoxylate but unaffected by the presence of ATP or AMP. Glyoxylate is an additional inhibitor to those previously reported for C. neoformans Xfp2. As with C. neoformans Xfp2, PEP and OAA share the same or possess overlapping sites on L. plantarum Xfp. Glyoxylate, which had the lowest half-maximal inhibitory concentration of the three inhibitors, binds at a separate site. This study demonstrates that substrate cooperativity and allosteric regulation may be common properties among bacterial and eukaryotic Xfp enzymes, yet important differences exist between the enzymes in these two domains. IMPORTANCE: Xylulose 5-phosphate/fructose 6-phosphate phosphoketolase (Xfp) plays a key role in carbohydrate metabolism in a number of bacteria. Although we recently demonstrated that the fungal Cryptococcus Xfp is subject to substrate cooperativity and allosteric regulation, neither phenomenon has been reported for a bacterial Xfp. Here, we report that the Lactobacillus plantarum Xfp displays substrate cooperativity and is allosterically inhibited by phosphoenolpyruvate and oxaloacetate, as is the case for Cryptococcus Xfp. The bacterial enzyme is unaffected by the presence of AMP or ATP, which act as a potent activator and inhibitor of the fungal Xfp, respectively. Our results demonstrate that substrate cooperativity and allosteric regulation may be common properties among bacterial and eukaryotic Xfps, yet important differences exist between the enzymes in these two domains.

Biochemical and kinetic characterization of xylulose 5-phosphate/fructose 6-phosphate phosphoketolase 2 (Xfp2) from Cryptococcus neoformans.

Xylulose 5-phosphate/fructose 6-phosphate phosphoketolase (Xfp), previously thought to be present only in bacteria but recently found in fungi, catalyzes the formation of acetyl phosphate from xylulose 5-phosphate or fructose 6-phosphate. Here, we describe the first biochemical and kinetic characterization of a eukaryotic Xfp, from the opportunistic fungal pathogen Cryptococcus neoformans, which has two XFP genes (designated XFP1 and XFP2). Our kinetic characterization of C. neoformans Xfp2 indicated the existence of both substrate cooperativity for all three substrates and allosteric regulation through the binding of effector molecules at sites separate from the active site. Prior to this study, Xfp enzymes from two bacterial genera had been characterized and were determined to follow Michaelis-Menten kinetics. C. neoformans Xfp2 is inhibited by ATP, phosphoenolpyruvate (PEP), and oxaloacetic acid (OAA) and activated by AMP. ATP is the strongest inhibitor, with a half-maximal inhibitory concentration (IC50) of 0.6 mM. PEP and OAA were found to share the same or have overlapping allosteric binding sites, while ATP binds at a separate site. AMP acts as a very potent activator; as little as 20 µM AMP is capable of increasing Xfp2 activity by 24.8% ± 1.0% (mean ± standard error of the mean), while 50 µM prevented inhibition caused by 0.6 mM ATP. AMP and PEP/OAA operated independently, with AMP activating Xfp2 and PEP/OAA inhibiting the activated enzyme. This study provides valuable insight into the metabolic role of Xfp within fungi, specifically the fungal pathogen Cryptococcus neoformans, and suggests that at least some Xfps display substrate cooperative binding and allosteric regulation.

Promoting good dental health in older people: role of the community nurse.

Good dental health enables a person to eat, speak, and socialise. It contributes to nutrition, general health, and quality of life. The dental health of people living in the UK has improved in the last 40 years, and older people are retaining their natural teeth throughout their life; nontheless, a significant proportion of people over 75 years still rely on partial and full dentures. Dental disease in all age groups is readily prevented by daily oral hygiene and adherence to a healthy diet, avoidance of smoking, and sensible alcohol intake. Some older people may simply need reminding and encouragement to carry out oral hygiene, while more dependent adults may need support and active help to do so. Nursing teams and health professionals play a key role in promoting oral health by supporting oral hygiene and adequate nutrition, preventing discomfort, and detecting dental diseases early. This article gives a brief overview of how nursing teams and health professionals can promote oral health and provides details of resources from which further detailed information may be obtained.

Racial Variation in Visual Impairment of Patients With Keratoconus at Presentation.

PURPOSE: This study aimed to investigate racial disparities in the severity of keratoconus (KCN) at presentation, their intersection with socioeconomic variables, and other factors associated with visual impairment. METHODS: This retrospective cohort study examined medical records of 1989 patients (3978 treatment-naive eyes) with a diagnosis of KCN seen at Wilmer Eye Institute between 2013 and 2020. A multivariable regression model adjusting for age, sex, race, insurance type, KCN family history, atopy, smoking status, and vision correction method examined factors associated with visual impairment, defined as a best available visual acuity of worse than 20/40 in the better eye. RESULTS: Demographically, Asian patients were the youngest (33.4 ± 14.0 years) ( P < 0.001), and Black patients had the highest median area deprivation index (ADI) of 37.0 [interquartile range (IQR): 21.0-60.5] ( P < 0.001). Multivariable analysis showed a higher risk of visual impairment for Black (OR 2.25, 95% CI, 1.71-2.95) versus White patients. Medicaid (OR 2.59, 95% CI, 1.75-3.83) and Medicare (OR 2.48, 95% CI, 1.51-4.07) were also associated with a higher odds of visual impairment compared with private insurance, and active smokers were more likely to have visual impairment than those with no prior smoking history (OR 2.17, 95% CI, 1.42-3.30). Eyes of Black patients had the highest maximum keratometry (Kmax) (56.0 ± 11.0D) ( P = 0.003) and the lowest thinnest pachymetry (463.2 ± 62.5 µm) ( P = 0.006) compared with eyes of other races. CONCLUSIONS: Black race, government-funded insurance, and active smoking were significantly associated with increased odds of visual impairment in adjusted analyses. Black race was also associated with higher Kmax and lower thinnest pachymetry, suggesting that Black patients have more severe disease at presentation.

Factors Associated With Receipt of Crosslinking for Keratoconus.

PURPOSE: The aim of this study was to identify factors associated with receipt of standard fluence epithelium-off crosslinking (CXL) for keratoconus (KCN). METHODS: This retrospective, cross-sectional study reviewed electronic health records of treatment-naive patients with KCN seen at the Wilmer Eye Institute between January 2017 and September 2020. Tomographic data were derived from Pentacam (Oculus, Wetzlar, Germany) devices. Multivariable population-average model using generalized estimating equations adjusting for age, sex, race, national area deprivation index, vision correction method, and disease severity was used to identify factors associated with receipt of CXL. RESULTS: From 583 patients with KCN, 97 (16.6%) underwent CXL for KCN. Patients who received CXL in at least 1 eye were significantly younger (mean 24.0 ± 7.8 years) than patients who had never undergone CXL (33.4 ± 9.3 years) ( P < 0.001). In multivariable analysis, Black patients had 63% lower odds of receiving CXL for KCN (OR: 0.37, 95% CI, 0.18-0.79) versus White patients, and older age was protective against receipt of CXL (OR: 0.89 per 1-year increase, 95% CI, 0.86-0.93). Comparison of characteristics by race demonstrated that Black patients presented with significantly worse vision, higher keratometric indices (K1, K2, and Kmax), and thinner corneal pachymetry at baseline versus White or Asian patients. CONCLUSIONS: In this clinical cohort of patients with KCN from a tertiary referral center, Black patients were less likely to receive CXL presumably because of more advanced disease at presentation. Earlier active population screening may be indicated to identify and treat these patients before they become ineligible for treatment and develop irreversible vision loss. Such strategies may improve health equity in KCN management.