Immediate and delayed flap reconstruction have equivalent outcomes and associated costs following soft tissue sarcoma surgery.

BACKGROUND AND OBJECTIVES: Surgical treatment of soft tissue sarcoma (STS) involves wide resection of the tumor, which can necessitate soft tissue reconstruction with local or free tissue flaps. This retrospective study compares cost, surgical and oncologic outcomes between patients undergoing reconstruction with immediate versus delayed flap coverage following STS resection. METHODS: Thirty-four patients who underwent planned flap reconstruction following resection of primary STS were identified retrospectively. Twenty-four (71%) received immediate reconstruction during the index surgery and 10 (29%) underwent planned delayed reconstruction. Preoperative patient-specific metrics, tumor characteristics, and surgical and patient outcomes were collected. Total hospital charges associated with every encounter during the perioperative period were obtained. RESULTS: Patient demographics, comorbidities, tumor metrics, and surgical characteristics were equivalent between groups. Postoperative wound complications, reoperations, readmissions, and disease-specific survival did not differ between cohorts. Costs associated with each reconstruction strategy were equivalent on bivariate and multivariate testing, when accounting for operating room time, hospital length of stay, and reoperation rate. CONCLUSIONS: Our study identifies no significant difference in patient outcome measures or cost between planned immediate and delayed flap reconstruction following STS resection. These results support the implementation of either treatment strategy in keeping with patient-centered, multidisciplinary care principles.

Evaluation of the early warning, alert and response system after Cyclone Winston, Fiji, 2016.

OBJECTIVE: To assess the performance of an early warning, alert and response system (EWARS) developed by the World Health Organization (WHO) - EWARS in a Box - that was used to detect and control disease outbreaks after Cyclone Winston caused destruction in Fiji on 20 February 2016. METHODS: Immediately after the cyclone, Fiji's Ministry of Health and Medical Services, supported by WHO, started to implement EWARS in a Box, which is a smartphone-based, automated, early warning surveillance system for rapid deployment during health emergencies. Both indicator-based and event-based surveillance were employed. The performance of the system between 7 March and 29 May 2016 was evaluated. Users' experience with the system was assessed in interviews using a semi-structured questionnaire and by a cross-sectional survey. The system's performance was assessed using data from the EWARS database. FINDINGS: Indicator-based surveillance recorded 34 113 cases of the nine syndromes under surveillance among 326 861 consultations. Three confirmed outbreaks were detected, and no large outbreak was missed. Users were satisfied with the performance of EWARS and judged it useful for timely monitoring of disease trends and outbreak detection. The system was simple, stable and flexible and could be rapidly deployed during a health emergency. The automated collation, analysis and dissemination of data reduced the burden on surveillance teams, saved human resources, minimized human error and ensured teams could focus on public health responses. CONCLUSION: In Fiji, EWARS in a Box was effective in strengthening disease surveillance during a national emergency and was well regarded by users.

Acoustical Direction Finding with Time-Modulated Arrays.

Time-Modulated Linear Arrays (TMLAs) offer useful efficiency savings over conventional phased arrays when applied in parameter estimation applications. The present paper considers the application of TMLAs to acoustic systems and proposes an algorithm for efficiently deriving the arrival angle of a signal. The proposed technique is applied in the frequency domain, where the signal and harmonic content is captured. Using a weighted average method on harmonic amplitudes and their respective main beam angles, it is possible to determine an estimate for the signal's direction of arrival. The method is demonstrated and evaluated using results from both numerical and practical implementations and performance data is provided. The use of Micro-Electromechanical Systems (MEMS) sensors allows time-modulation techniques to be applied at ultrasonic frequencies. Theoretical predictions for an array of five isotropic elements with half-wavelength spacing and 1000 data samples suggest an accuracy of ± 1 ∘ within an angular range of approximately ± 50 ∘ . In experiments of a 40 kHz five-element microphone array, a Direction of Arrival (DoA) estimation within ± 2 . 5 ∘ of the target signal is readily achieved inside a ± 45 ∘ range using a single switched input stage and a simple hardware setup.

A feasibility study determining surgical ergonomics in a live surgical setting.

STUDY OBJECTIVE: To identify the biomechanical movements of laparoscopic surgeons during laparoscopic gynecologic procedures, and to determine whether such movements can be assessed and measured both temporally and biomechanically. DESIGN: Prospective descriptive kinematic study (Canadian Task Force classification II-3). SETTING: A tertiary referral hospital in Sydney, Australia. STUDY SUBJECTS: Five gynecologic laparoscopic surgeons. INTERVENTIONS: Video recording from a variety of fixed positions to assess surgeon stance, time spent in specific postures, and relative change of limb angles during laparoscopic surgical procedures. MEASUREMENTS AND MAIN RESULTS: Postoperative review of surgical movements during laparoscopic surgery was able to provide quantitative data. Motion and timing could be classified by angle banding ranges among surgeons. The most extreme shoulder abduction angles occurred during trocar insertion (61°) and insertion or removal of laparoscopic instruments (63.5°), with procedures involving morcellation requiring the greatest number of instrument insertions or removals (n = 57). The elbow is most frequently in a neutral position in TLH, and the shoulder spends the most time in abduction during myomectomy. CONCLUSION: This proof-of-concept study confirms that detailed ergonomic assessment is possible within live surgical settings, with identified limitations. This study may allow for a larger-scale study to determine at-risk movements during the various phases of a laparoscopic surgery and possibly control for some of these hazardous behaviors.

How nature can exploit nonspecific catalytic and carbohydrate binding modules to create enzymatic specificity.

Noncatalytic carbohydrate binding modules (CBMs) are components of glycoside hydrolases that attack generally inaccessible substrates. CBMs mediate a two- to fivefold elevation in the activity of endo-acting enzymes, likely through increasing the concentration of the appended enzymes in the vicinity of the substrate. The function of CBMs appended to exo-acting glycoside hydrolases is unclear because their typical endo-binding mode would not fulfill a targeting role. Here we show that the Bacillus subtilis exo-acting ß-fructosidase SacC, which specifically hydrolyses levan, contains the founding member of CBM family 66 (CBM66). The SacC-derived CBM66 (BsCBM66) targets the terminal fructosides of the major fructans found in nature. The crystal structure of BsCBM66 in complex with ligands reveals extensive interactions with the terminal fructose moiety (Fru-3) of levantriose but only limited hydrophobic contacts with Fru-2, explaining why the CBM displays broad specificity. Removal of BsCBM66 from SacC results in a ~100-fold reduction in activity against levan. The truncated enzyme functions as a nonspecific ß-fructosidase displaying similar activity against ß-2,1- and ß-2,6-linked fructans and their respective fructooligosaccharides. Conversely, appending BsCBM66 to BT3082, a nonspecific ß-fructosidase from Bacteroides thetaiotaomicron, confers exolevanase activity on the enzyme. We propose that BsCBM66 confers specificity for levan, a branched fructan, through an "avidity" mechanism in which the CBM and the catalytic module target the termini of different branches of the same polysaccharide molecule. This report identifies a unique mechanism by which CBMs modulate enzyme function, and shows how specificity can be tailored by integrating nonspecific catalytic and binding modules into a single enzyme.

Multi-Province Listeriosis Outbreak Linked to Contaminated Deli Meat Consumed Primarily in Institutional Settings, Canada, 2008.

A multi-province outbreak of listeriosis occurred in Canada from June to November 2008. Fifty-seven persons were infected with 1 of 3 similar outbreak strains defined by pulsed-field gel electrophoresis, and 24 (42%) individuals died. Forty-one (72%) of 57 individuals were residents of long-term care facilities or hospital inpatients during their exposure period. Descriptive epidemiology, product traceback, and detection of the outbreak strains of Listeria monocytogenes in food samples and the plant environment confirmed delicatessen meat manufactured by one establishment and purchased primarily by institutions was the source of the outbreak. The food safety investigation identified a plant environment conducive to the introduction and proliferation of L. monocytogenes and persistently contaminated with Listeria spp. This outbreak demonstrated the need for improved listeriosis surveillance, strict control of L. monocytogenes in establishments producing ready-to-eat foods, and advice to vulnerable populations and institutions serving these populations regarding which high-risk foods to avoid.

Salmonella typhimurium infections associated with peanut products.

BACKGROUND: Contaminated food ingredients can affect multiple products, each distributed through various channels and consumed in multiple settings. Beginning in November 2008, we investigated a nationwide outbreak of salmonella infections. METHODS: A case was defined as laboratory-confirmed infection with the outbreak strain of Salmonella Typhimurium occurring between September 1, 2008, and April 20, 2009. We conducted two case-control studies, product "trace-back," and environmental investigations. RESULTS: Among 714 case patients identified in 46 states, 166 (23%) were hospitalized and 9 (1%) died. In study 1, illness was associated with eating any peanut butter (matched odds ratio, 2.5; 95% confidence interval [CI], 1.3 to 5.3), peanut butter-containing products (matched odds ratio, 2.2; 95% CI, 1.1 to 4.7), and frozen chicken products (matched odds ratio, 4.6; 95% CI, 1.7 to 14.7). Investigations of focal clusters and single cases associated with nine institutions identified a single institutional brand of peanut butter (here called brand X) distributed to all facilities. In study 2, illness was associated with eating peanut butter outside the home (matched odds ratio, 3.9; 95% CI, 1.6 to 10.0) and two brands of peanut butter crackers (brand A: matched odds ratio, 17.2; 95% CI, 6.9 to 51.5; brand B: matched odds ratio, 3.6; 95% CI, 1.3 to 9.8). Both cracker brands were made from brand X peanut paste. The outbreak strain was isolated from brand X peanut butter, brand A crackers, and 15 other products. A total of 3918 peanut butter-containing products were recalled between January 10 and April 29, 2009. CONCLUSIONS: Contaminated peanut butter and peanut products caused a nationwide salmonellosis outbreak. Ingredient-driven outbreaks are challenging to detect and may lead to widespread contamination of numerous food products.

A brief description of the epidemiology of dengue in Dili, Timor-Leste, 2018-2022.

Abstract: Dengue virus (DENV) infection causes 390 million infections per year and 40,000 deaths globally. It is endemic in many countries in Asia, Africa, the Americas, the Caribbean, and Oceania. Dengue is endemic in Timor-Leste year-round, but peak transmission occurs during the rainy season. We briefly describe the epidemiology of DENV in the Municipality of Dili between 2018 and 2022. There were 6,234 cases notified, with a mean annual incidence rate of 330 cases per 100,000 population. There were 55 deaths (case fatality rate 0.9%). The peak annual incidence (3,904 cases) occurred in 2022 after an outbreak was declared in January of that year; this outbreak included 760 cases of dengue haemorrhagic fever and 35 deaths. The number of outbreak cases requiring hospital treatment exceeded the usual capacity, but facilities established for coronavirus disease 2019 (COVID-19) isolation and treatment were repurposed to meet this demand. Existing strategies of vector control, minimising breeding sites and promoting early presentation for treatment should continue, as should the utilisation of surveillance systems and treatment facilities established during the COVID-19 pandemic. However, dengue incidence remains high, and other dengue control strategies-including the deployment of Wolbachia-infected mosquitoes-should be considered in Timor-Leste.

Comparison of the burden of diarrhoeal illness among individuals with and without household cisterns in northeast Brazil.

BACKGROUND: Lack of access to safe and secure water is an international issue recognized by the United Nations. To address this problem, the One Million Cisterns Project was initiated in 2001 in Brazil's semi-arid region to provide a sustainable source of water to households. The objectives of this study were to determine the 30-day period prevalence of diarrhoea in individuals with and without cisterns and determine symptomology, duration of illness and type of health care sought among those with diarrhoea. A subgroup analysis was also conducted among children less than five years old. METHODS: A face-to-face survey was conducted between August 20th and September 20th, 2007 in the Agreste Central Region of Pernambuco State, Brazil. Households with and without a cistern that had at least one child under the age of five years were selected using systematic convenient sampling. Differences in health outcomes between groups were assessed using Pearson's Chi-squared and two-way t-tests. Demographic variables were tested for univariable associations with diarrhoea using logistic regression with random effects. P-values of 0.05 or less were considered statistically significant. RESULTS: A total of 3679 people from 774 households were included in the analysis (1863 people from 377 households with cisterns and 1816 people from 397 households without cisterns). People from households with a cistern had a significantly lower 30-day period prevalence of diarrhoea (prevalence = 11.0%; 95% CI 9.5-12.4) than people from households without a cistern (prevalence = 18.2%; 95% CI 16.4-20.0). This significant difference was also found in a subgroup analysis of children under five years old; those children with a cistern had a 30-day period prevalence of 15.6% (95% CI 12.3-18.9) versus 26.7% (95% CI 22.8-30.6) in children without a cistern. There were no significant differences between those people with and without cisterns in terms of the types of symptoms, duration of illness and health care sought for diarrhoea. CONCLUSIONS: Our results indicate that the use of cisterns for drinking water is associated with a decreased occurrence of diarrhoea in this study population. Further research accounting for additional risk factors and preventative factors should be conducted.

Rosai-Dorfman: Rare Manifestations of a Rare Disease.

Rosai-Dorfman disease (RDD) is an exceedingly rare non-Langerhans cell histiocytosis of uncertain etiology that most commonly presents in children as self-limited, painless, massive cervical lymphadenopathy. However, extranodal disease occurs in 43% of cases and has a wide range of phenotypic presentations. The pathogenesis has not been clearly understood in the literature and coupled with a wide range of clinical manifestations, early diagnosis and initiation of an appropriate treatment modality have been challenging. Herein, we describe a cohort of five cases that occurred at the same institution within a 12-month period. These cases highlight unique and atypical presentations of an already rare disease, outline the varying and tailored diagnostic and therapeutic approaches, and propose a novel environmental predisposing factor given the exceptionally high incidence at our institution over a short period of time. We emphasize the need for further investigation of predisposing factors and to discern targeted therapies that may offer benefits.

Involvement and readiness of fellows from Papua New Guinea's Field Epidemiology Training Programme in the COVID-19 response, 2020-2021.

Problem: Fellows of the Papua New Guinea Field Epidemiology Training Programme (FETP) were part of the national coronavirus disease (COVID-19) response. However, the specific activities and challenges experienced by fellows in the field were unknown. Context: The advanced FETP cohort commenced just before the COVID-19 pandemic and all fellows were involved in the response. The advanced fellows participating in this review represented a cross-section of the country's public health workforce. Action: A review was conducted to better understand the scope of activities undertaken by FETP fellows, identify the challenges experienced and assess how well the programme prepared fellows for their COVID-19 response roles. A facilitated discussion based on the World Health Organization COVID-19 intra-action review methodology and an online survey was conducted with advanced FETP fellows. Outcome: The fellows made important contributions to the national COVID-19 response by assuming leadership positions at all levels of government, leading training activities and applying core field epidemiology competencies in surveillance and response activities. The programme had prepared them well for the response, giving them the confidence and skills to undertake a diverse range of response roles. Discussion: The FETP review of the COVID-19 response in Papua New Guinea highlighted the role and influence of the fellows during the pandemic response. Fellows were able to apply core field epidemiology competencies across a range of roles. The recommendations derived from this review will be instructive for the FETP specifically and the COVID-19 response generally.

Substrate and metal ion promiscuity in mannosylglycerate synthase.

The enzymatic transfer of the sugar mannose from activated sugar donors is central to the synthesis of a wide range of biologically significant polysaccharides and glycoconjugates. In addition to their importance in cellular biology, mannosyltransferases also provide model systems with which to study catalytic mechanisms of glycosyl transfer. Mannosylglycerate synthase (MGS) catalyzes the synthesis of α-mannosyl-D-glycerate using GDP-mannose as the preferred donor species, a reaction that occurs with a net retention of anomeric configuration. Past work has shown that the Rhodothermus marinus MGS, classified as a GT78 glycosyltransferase, displays a GT-A fold and performs catalysis in a metal ion-dependent manner. MGS shows very unusual metal ion dependences with Mg(2+) and Ca(2+) and, to a lesser extent, Mn(2+), Ni(2+), and Co(2+), thus facilitating catalysis. Here, we probe these dependences through kinetic and calorimetric analyses of wild-type and site-directed variants of the enzyme. Mutation of residues that interact with the guanine base of GDP are correlated with a higher k(cat) value, whereas substitution of His-217, a key component of the metal coordination site, results in a change in metal specificity to Mn(2+). Structural analyses of MGS complexes not only provide insight into metal coordination but also how lactate can function as an alternative acceptor to glycerate. These studies highlight the role of flexible loops in the active center and the subsequent coordination of the divalent metal ion as key factors in MGS catalysis and metal ion dependence. Furthermore, Tyr-220, located on a flexible loop whose conformation is likely influenced by metal binding, also plays a critical role in substrate binding.

A novel, noncatalytic carbohydrate-binding module displays specificity for galactose-containing polysaccharides through calcium-mediated oligomerization.

The enzymic degradation of plant cell walls plays a central role in the carbon cycle and is of increasing environmental and industrial significance. The catalytic modules of enzymes that catalyze this process are generally appended to noncatalytic carbohydrate-binding modules (CBMs). CBMs potentiate the rate of catalysis by bringing their cognate enzymes into intimate contact with the target substrate. A powerful plant cell wall-degrading system is the Clostridium thermocellum multienzyme complex, termed the "cellulosome." Here, we identify a novel CBM (CtCBM62) within the large C. thermocellum cellulosomal protein Cthe_2193 (defined as CtXyl5A), which establishes a new CBM family. Phylogenetic analysis of CBM62 members indicates that a circular permutation occurred within the family. CtCBM62 binds to d-galactose and l-arabinopyranose in either anomeric configuration. The crystal structures of CtCBM62, in complex with oligosaccharides containing α- and ß-galactose residues, show that the ligand-binding site in the ß-sandwich protein is located in the loops that connect the two ß-sheets. Specificity is conferred through numerous interactions with the axial O4 of the target sugars, a feature that distinguishes galactose and arabinose from the other major sugars located in plant cell walls. CtCBM62 displays tighter affinity for multivalent ligands compared with molecules containing single galactose residues, which is associated with precipitation of these complex carbohydrates. These avidity effects, which confer the targeting of polysaccharides, are mediated by calcium-dependent oligomerization of the CBM.

The active site of a carbohydrate esterase displays divergent catalytic and noncatalytic binding functions.

Multifunctional proteins, which play a critical role in many biological processes, have typically evolved through the recruitment of different domains that have the required functional diversity. Thus the different activities displayed by these proteins are mediated by spatially distinct domains, consistent with the specific chemical requirements of each activity. Indeed, current evolutionary theory argues that the colocalization of diverse activities within an enzyme is likely to be a rare event, because it would compromise the existing activity of the protein. In contrast to this view, a potential example of multifunctional recruitment into a single protein domain is provided by CtCel5C-CE2, which contains an N-terminal module that displays cellulase activity and a C-terminal module, CtCE2, which exhibits a noncatalytic cellulose-binding function but also shares sequence identity with the CE2 family of esterases. Here we show that, unlike other CE2 members, the CtCE2 domain displays divergent catalytic esterase and noncatalytic carbohydrate binding functions. Intriguingly, these diverse activities are housed within the same site on the protein. Thus, a critical component of the active site of CtCE2, the catalytic Ser-His dyad, in harness with inserted aromatic residues, confers noncatalytic binding to cellulose whilst the active site of the domain retains its esterase activity. CtCE2 catalyses deacetylation of noncellulosic plant structural polysaccharides to deprotect these substrates for attack by other enzymes. Yet it also acts as a cellulose-binding domain, which promotes the activity of the appended cellulase on recalcitrant substrates. The CE2 family encapsulates the requirement for multiple activities by biocatalysts that attack challenging macromolecular substrates, including the grafting of a second, powerful and discrete noncatalytic binding functionality into the active site of an enzyme. This article provides a rare example of "gene sharing," where the introduction of a second functionality into the active site of an enzyme does not compromise the original activity of the biocatalyst.

Evidence that family 35 carbohydrate binding modules display conserved specificity but divergent function.

Enzymes that hydrolyze complex carbohydrates play important roles in numerous biological processes that result in the maintenance of marine and terrestrial life. These enzymes often contain noncatalytic carbohydrate binding modules (CBMs) that have important substrate-targeting functions. In general, there is a tight correlation between the ligands recognized by bacterial CBMs and the substrate specificity of the appended catalytic modules. Through high-resolution structural studies, we demonstrate that the architecture of the ligand binding sites of 4 distinct family 35 CBMs (CBM35s), appended to 3 plant cell wall hydrolases and the exo-beta-D-glucosaminidase CsxA, which contributes to the detoxification and metabolism of an antibacterial fungal polysaccharide, is highly conserved and imparts specificity for glucuronic acid and/or Delta4,5-anhydrogalaturonic acid (Delta4,5-GalA). Delta4,5-GalA is released from pectin by the action of pectate lyases and as such acts as a signature molecule for plant cell wall degradation. Thus, the CBM35s appended to the 3 plant cell wall hydrolases, rather than targeting the substrates of the cognate catalytic modules, direct their appended enzymes to regions of the plant that are being actively degraded. Significantly, the CBM35 component of CsxA anchors the enzyme to the bacterial cell wall via its capacity to bind uronic acid sugars. This latter observation reveals an unusual mechanism for bacterial cell wall enzyme attachment. This report shows that the biological role of CBM35s is not dictated solely by their carbohydrate specificities but also by the context of their target ligands.

Vitamin D Deficiency in the Military: It's Time to Act!

Vitamin D is critically important to numerous physiologic functions, including bone health. Poor vitamin D status is a common but underrecognized problem that predisposes the military population to stress fracture and completed fracture. This has significant implications for force health protection, warfighter readiness, attrition, and cost. Despite this, vitamin D deficiency is still underdiagnosed and undertreated in the military. This is a major hindrance to military readiness and one that could easily be modified with awareness, prevention, and early treatment. In this commentary, we review the literature on vitamin D deficiency and critically examine the current status of policies and clinical practice related to vitamin D in the military health system. We offer several practical recommendations to increase awareness and readiness while decreasing musculoskeletal injury and the associated costs.

Metastatic Endometrioid Carcinoma Mimicking a Subungual Melanoma.

CASE: We report a case of a 76-year-old female with a stage IB, grade I endometrioid endometrial carcinoma who presented with right-hip pain and an enlarging black, exophytic, subungual lesion on her right-small-finger distal phalanx. Clinically, the distal phalanx lesion was suspicious for a subungual melanoma; however, advanced imaging suggested metastatic disease, with lesions in the acetabulum, lungs, brain, vulva, and vagina. CONCLUSION: Partial amputation of the right, small finger and vulvar biopsies confirmed an endometrial carcinoma. To our knowledge, this is the first described case of endometrial adenocarcinoma metastasis to the phalanx of an upper extremity, mimicking a subungual melanoma.

Ready to respond: adapting rapid response team training in Papua New Guinea during the COVID-19 pandemic.

Problem: Rapid response teams (RRTs) are critical for effective responses to acute public health events. While validated training packages and guidance on rolling out training for RRTs are available, they lack country-specific adaptations. Documentation is limited on RRT programming experiences in various contexts. Context: In Papua New Guinea, there remain gaps in implementing standardized, rapid mobilization of multidisciplinary RRTs at the national, provincial and district levels to investigate public health alerts. Action: The human resources needed to respond to the coronavirus disease (COVID-19) pandemic forced a review of the RRT training programme and its delivery. The training model was contextualized and adapted for implementation using a staged approach, with the initiation training phase designed to ensure RRT readiness to deploy immediately in response to COVID-19 and other public health events. Lessons learned: Selecting appropriate trainees and using a phased training approach, incorporating after-training reviews, and between-phase support from the national programme team were found to be important for programme design in Papua New Guinea. Using participatory training methods based on principles of adult learning, in which trainees draw on their own experiences, was integral to building confidence among team members in conducting outbreak investigations. Discussion: The RRT training experience in Papua New Guinea has highlighted the importance of codeveloping and delivering a context-specific training programme to meet a country's unique needs. A staged training approach that builds on knowledge and skills over time, used together with ongoing follow-up and support in the provinces, has been critical in operationalizing ready-to-respond RRTs.

Circular permutation provides an evolutionary link between two families of calcium-dependent carbohydrate binding modules.

The microbial deconstruction of the plant cell wall is a critical biological process, which also provides important substrates for environmentally sustainable industries. Enzymes that hydrolyze the plant cell wall generally contain non-catalytic carbohydrate binding modules (CBMs) that contribute to plant cell wall degradation. Here we report the biochemical properties and crystal structure of a family of CBMs (CBM60) that are located in xylanases. Uniquely, the proteins display broad ligand specificity, targeting xylans, galactans, and cellulose. Some of the CBM60s display enhanced affinity for their ligands through avidity effects mediated by protein dimerization. The crystal structure of vCBM60, displays a ß-sandwich with the ligand binding site comprising a broad cleft formed by the loops connecting the two ß-sheets. Ligand recognition at site 1 is, exclusively, through hydrophobic interactions, whereas binding at site 2 is conferred by polar interactions between a protein-bound calcium and the O2 and O3 of the sugar. The observation, that ligand recognition at site 2 requires only a ß-linked sugar that contains equatorial hydroxyls at C2 and C3, explains the broad ligand specificity displayed by vCBM60. The ligand-binding apparatus of vCBM60 displays remarkable structural conservation with a family 36 CBM (CBM36); however, the residues that contribute to carbohydrate recognition are derived from different regions of the two proteins. Three-dimensional structure-based sequence alignments reveal that CBM36 and CBM60 are related by circular permutation. The biological and evolutionary significance of the mechanism of ligand recognition displayed by family 60 CBMs is discussed.