An extensive field study reveals the circulation of new genetic variants of subtype 1a of bovine viral diarrhea virus in Uruguay.

Bovine viral diarrhea virus (BVDV) is a major pathogen worldwide, causing significant economic losses to the livestock sector. In Uruguay, BVDV seroprevalence at the farm level is >80%. In this work, 2546 serum, blood or tissue samples collected from animals suspected of being affected by BVD between 2015 and 2017 were analyzed by reverse transcription PCR and sequencing. Analysis of the BVDV genomic regions 5'UTR/Npro, Npro and E2 revealed that BVDV-1a, 1i and 2b circulate in the country, with BVDV-1a being the most prevalent subtype. Population dynamics studies revealed that BVDV-1a has been circulating in our herds since ~1990. This subtype began to spread and evolve, accumulating point mutations at a rate of 3.48 × 10-3 substitutions/site/year, acquiring specific genetic characteristics that gave rise to two local genetic lineages of BVDV-1a. These lineages are divergent from those circulating worldwide, as well as the vaccine strain currently used in Uruguay. The most notable differences between field and vaccine strains were found in the E2 glycoprotein, suggesting that the amino acid substitutions could result in failure of cross-protection/neutralization after vaccination. This is the first study that compares Uruguayan BVDV field and vaccine strains with other BVDV strains from throughout the world. The results obtained in this study will be very useful for developing a suitable immunization program for BVDV in Uruguay by identifying local field strains as candidates for vaccine development.

Isoforms of the DHTKD1-Encoded 2-Oxoadipate Dehydrogenase, Identified in Animal Tissues, Are not Observed upon the Human DHTKD1 Expression in Bacterial or Yeast Systems.

Unlike the OGDH-encoded 2-oxoglutarate dehydrogenase (OGDH), which is an essential enzyme present in all animal tissues, expression of the DHTKD1-encoded isoenzyme, 2-oxoadipate dehydrogenase (OADH), depends on a number of factors, and mutant DHTKD1 phenotypes are rarely manifested. Physiological significance of OADH is also obscured by the fact that both isoenzymes transform 2-oxoglutarate and 2-oxoadipate. By analogy with other members of the 2-oxo acid dehydrogenases family, OADH is assumed to be a component of the multienzyme complex that catalyzes oxidative decarboxylation of 2-oxoadipate. This study aims at molecular characterization of OADH from animal tissues. Phylogenetic analysis of 2-oxo acid dehydrogenases reveals OADH only in animals and Dictyostelium discoideum slime mold, within a common branch with bacterial OGDH. Examination of partially purified animal OADH by immunoblotting and mass spectrometry identifies two OADH isoforms with molecular weights of about 130 and 70 kDa. These isoforms are not observed upon the expression of human DHTKD1 protein in either bacterial or yeast system, where the synthesized OADH is of expected molecular weight (about 100 kDa). Thus, the OADH isoforms present in animal tissues, may result from the animal-specific regulation of the DHTKD1 expression and/or posttranslational modifications of the encoded protein. Mapping of the peptides identified in the OADH preparations, onto the protein structure suggests that the 70-kDa isoform is truncated at the N-terminus, but retains the active site. Since the N-terminal domain of OGDH is required for the formation of the multienzyme complex, it is possible that the 70-kDa isoform catalyzes non-oxidative transformation of dicarboxylic 2-oxo acids that does not require the multienzyme structure. In this case, the ratio of the OADH isoforms in animal tissues may correspond to the ratio between the oxidative and non-oxidative decarboxylation of 2-oxoadipate.

Molecular detection of Bartonella in fleas (Hexapoda, Siphonaptera) collected from wild rodents (Cricetidae, Sigmodontinae) from Argentina.

Bartonella are facultative intracellular Gram-negative bacteria, transmitted mainly by hematophagous arthropods, and the rodents act as a natural reservoir. Different species of Bartonella associated with rodents have been implicated as causing human disease. Studies from Argentina are scarce and no Bartonella from fleas have been reported previously. The present study investigated the presence of Bartonella spp. in fleas associated with sigmodontine rodents in four localities of the Santa Cruz Province, Argentina. In total, 51 fleas (four species) were analysed of which 41.2% were found to be positive for the gltA gene fragment via a nested polymerase chain reaction. All positive fleas were of the species Neotyphloceras crackensis from three different localities. Eight of the 21 amplified samples were sequenced, and the presence of three different genotypes was detected with an identity of 95.5-98.8% amongst themselves. Bartonella genotypes from American rodents and rodent fleas were recovered in a monophyletic group. Similarly, most of the Peruvian and all Argentinean variants constitute a natural group sister of the American remainder. The importance of the Bartonella spp. with respect to public health is unknown, although future studies could provide evidence of the possible involvement of N. crackensis in the Bartonella transmission cycles.

[Molecular detection of Rickettsia massiliae and Anaplasma platys infecting Rhipicephalus sanguineus ticks and dogs, Bahía Blanca (Argentina)]. / Detección molecular de Rickettsia massiliae y Anaplasma platys en garrapatas Rhipicephalus sanguineus y caninos domésticos del municipio de Bahía Blanca (Argentina).

BACKGROUND: Rickettsioses, ehrlichioses and anaplasmoses are caused by Gram negative obligate intracellular bacteria and transmitted mainly by arthropods. AIM: To detect and perform the molecular characterization of these pathogens in ticks and domestic dogs in Bahia Blanca City (Buenos Aires, Argentina). METHODS: Fifty six blood samples from dogs and 82 ticks (75 Rhipicephalus sanguineus and 7 Amblyomma tigrinum) were studied. The samples were analyzed by PCR for Rickettsia (intergenic space 23S-5S rRNA), Ehrlichia/Anaplasma (16S rRNA), and Anaplasma platys (16S rRNA). RESULTS: 12% of R. sanguineus resulted positive for Rickettsia, identified by sequencing as Rickettsia massiliae; and 37.5% of the canine blood samples analyzed were positive for A. platys. Molecular characterization was also performed by amplification of the fragment of the citrate synthase gene (gltA) (Rickettsia genus) and the groESL gene (A. platys). Phylogenetic trees were constructed using the neighbor-joining method. These trees revealed that sequences obtained are similar to those from other geographical regions. CONCLUSION: The results indicate the presence of R. massiliae in R. sanguineus ticks for the second time in an urban area of South America and A. platys infection in dogs, being the southernmost region of Argentina where it has been notified.

Estimating the savings of a national project to prevent healthcare-associated infections in intensive care units.

BACKGROUND: Healthcare-associated infections (HAIs) have a significant impact on patients' morbidity and mortality, and have a detrimental financial impact on the healthcare system. Various strategies exist to prevent HAIs, but economic evaluations are needed to determine which are most appropriate. AIM: To present the financial impact of a nationwide project on HAI prevention in intensive care units (ICUs) using a quality improvement (QI) approach. METHODS: A health economic evaluation assessed the financial results of the QI initiative 'Saúde em Nossas Mãos' (SNM), implemented in Brazil between January 2018 and December 2020. Among 116 participating institutions, 13 (11.2%) fully reported the aggregate cost and stratified patients (with vs without HAIs) in the pre-intervention and post-intervention periods. Average cost (AC) was calculated for each analysed HAI: central-line-associated bloodstream infections (CLABSIs), ventilator-associated pneumonia (VAP) and catheter-associated urinary tract infections (CAUTIs). The absorption model and time-driven activity-based costing were used for cost estimations. The numbers of infections that the project could have prevented during its implementation were estimated to demonstrate the financial impact of the SNM initiative. RESULTS: The aggregated ACs calculated for each HAI from these 13 ICUs - US$8480 for CLABSIs, US$10,039 for VAP, and US$7464 for CAUTIs - were extrapolated to the total number of HAIs prevented by the project (1727 CLABSIs, 3797 VAP and 2150 CAUTIs). The overall savings of the SNM as of December 2020 were estimated at US$68.8 million, with an estimated return on investment (ROI) of 765%. CONCLUSION: Reporting accurate financial data on HAI prevention strategies is still challenging in Brazil. These results suggest that a national QI initiative to prevent HAIs in critical care settings is a feasible and value-based approach, reducing financial waste and yielding a significant ROI for the healthcare system.

Detection of Neorickettsia sp. in Oligoryzomys flavescens rodent from a protected urban area in Buenos Aires City (Argentina).

Rodents play an important role in vector-borne pathogens cycle. To detect Anaplasma, Ehrlichia, Neorickettsia, Rickettsia and Borrelia species in rodents from a protected urban area in Buenos Aires City (Argentina) were analyzed 203 organ pools of Mus musculus, Oligoryzomys flavescens, Rattus norvegicus, Deltamys kempi and Scapteromys aquaticus by PCR. Only one O. flavescens (1.2%) was positive by PCR for 16S rRNA fragment for the Anaplasmataceae family and the sequence had 99.7% identity with Neorickettsia risticii. Plus, the sequence obtained for a fragment of the p51 gene for the genus Neorickettsia from positive sample had 95.3-96.1% identity with N. risticii found previously in bats Tadarida brasiliensis from Buenos Aires City. Our study presents the first finding of Neorickettsia in rodents from natural environment, but further studies are necessary about these vector-borne bacteria and the rol of rodents in its epidemiology.

One-Year Surveillance of SARS-CoV-2 and Rotavirus in Water Matrices from a Hot Spring Area.

The pandemic of Coronavirus Disease 2019 (COVID-19) caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is still impacting not only on human health but also all economic activities, especially in those related to tourism. In this study, in order to characterize the presence of SARS-CoV-2 in a hot spring park in Uruguay, swimming pools water, wastewater, and surface water from this area were analyzed by quantitative PCR. Wastewater from Salto city located next to the hydrothermal spring area was also evaluated as well as the presence of Rotavirus (RV). Overall, SARS-CoV-2 was detected in 13% (13/102) of the analyzed samples. Moreover, this virus was not detected in any of the samples from the swimming pools water and was present in 18% (3/17) of wastewater samples from the hotels area showing the same trend between the titer of SARS-CoV-2 and the number of infected people in Salto city. SARS-CoV-2 was also detected in wastewater samples (32% (11/34)) from Salto city, detecting the first positive sample when 105 persons were positive for SARS-CoV-2. Rotavirus was detected only in 10% (2/24) of the wastewater samples analyzed in months when partial lockdown measures were taken, however, this virus was detected in nearly all wastewater samples analyzed when social distancing measures and partial lockdown were relaxed. Wastewater results confirmed the advantages of using the detection and quantification of viruses in this matrix in order to evaluate the presence of these viruses in the population, highlighting the usefulness of this approach to define and apply social distancing. This study suggests that waters from swimming pools are not a source of infection for SARS-CoV-2, although more studies are needed including infectivity assays in order to confirm this statement.

Microstructure characterization of erosion resistant coatings on carbon-bonded carbon fibre composites.

The microstructure of as received and surface treated carbon-bonded carbon fibre composites has been examined by light microscopy, scanning and transmission electron microscopy. The microstructure of the as received material consists of a bonded together layered carbon fiber network, identified as graphitic carbon (hexagonal close packed). To improve the erosion resistance of the carbon-bonded carbon fibre composites composite, the SiC and silicate glass-ceramic coatings from the system SiO(2)-Al(2)O(3)-Y(2)O(3) were produced on carbon-bonded carbon fibre composites composites by a low-cost slurry technique. Transmission electron microscopy investigations of cross-section thin foils allowed for detailed analysis of the coatings microstructure. It was found that the SiC coating was consisting mainly of a nanocrystalline SiC (fcc). The multilayered glass-ceramic coating showed a complex microstructure consisting of an external SiO(2)-Al(2)O(3)-Y(2)O(3) layer and an intermediate nanocrystalline SiC layer. The SiO(2)-Al(2)O(3)-Y(2)O(3) layer was composed of SiO(2) (fcc), Y(2)Si(2)O(7) (op) and Al(4.644)Si(1.357)O(9.68) (op).

Preoperative fasting - "nihil per os" a difficult myth to break down: a randomized controlled study.

INTRODUCTION: For several years the scientific anaesthesia societies declared a preoperative fast of 6 hours for solid foods and 2 hours for clear liquids before elective surgical interventions to be sufficient. The aim of this study is to identify the extent of the gap that exists between the preoperative fasting time required and that actually encountered in operating rooms. PATIENTS AND METHODS: The safety and clinical applicability of a reduction of the preoperative fasting time was investigated through the use of oral solutions enriched with maltodextrin and their effects on the pre- and postoperative well-being that this may have on patients who are candidates for elective abdominal surgery. The study was conducted in two successive phases (I and II) and patients divided into two groups (A and B). DISCUSSION: Clinical practice is slow to change, in fact, in our study the duration of fasting was an average of 19 hours for solids and 13 hours for liquids. The duration of the fasting did not show differences in the various surgical departments, demonstrating that it is a transversal practice and is not only limited to abdominal surgery in which the utility of fasting would theoretically be greater. Among Group patients A, the fasting time for liquids was about 9 hours. This shows that the time is certainly shorter but not much different when compared to the fasting time for liquids in group B which was on average 14 hours. It is important how difficult it is to achieve good compliance from patients when trying to reduce the time of preoperative fasting based on scientific evidence that is now well established. CONCLUSION: The use of carbohydrate-enriched drinks up to 2 hours after induction of anaesthesia appears to be a safe procedure. The use of these solutions reduces the catabolic response to surgery and contributes to maintaining a pre-operative state of well-being by reducing feelings of hunger and thirst and the state of preoperative anxiety.

Surgical repair of the distal biceps brachii tendon: clinical and isokinetic long-term follow-up.

Anatomical reinsertion of the avulsed distal biceps tendon is the recommended treatment, but the results are hampered by complications. The purpose of this study is to show the results of patients surgically treated with a non-anatomical reinsertion of this tendon. From 1972 to 2006, 26 non-professional athletic patients were surgically treated by suture of the tendon on the brachialis muscle tendon. At follow-up 23/26 patients underwent clinical and isokinetic evaluation. At a medium follow-up of 84 months, patients provided satisfactory subjective and objective clinical results. Flexion was restored in all patients, while a 10 degrees supination deficit was found in two patients. Dynamometric tests showed satisfactory results both regarding Maximum Strength Power and Endurance tests. Reinsertion of the distal biceps tendon on the brachialis tendon can be considered, in a long-term follow-up, a safe and effective procedure, with low complication rate.

Long term results of unprotected left main percutaneous coronary intervention with DES versus BMS.

AIM: Stenosis in the unprotected left main coronary artery (ULMCA) is considered a standard indication for surgical revascularization. Some studies have demonstrated that stenting of the ULMCA is safe and feasible in selected patients. Drug eluting stents (DES) have been shown to be superior to bare metal stents (BMS) in reducing restenosis and major adverse cardiac events (MACE) both in-hospital and at follow-up after treatment of ULMCA disease. Several studies showed that the mid-term prognosis of patients with left main stenting is good, but most of them are limited by small populations and the availability of mid-term results. Thus, we sought to evaluate the very long term impact of DES vs BMS in a large cohort of patients undergoing stent implantation for ULMCA disease in our center. METHODS: Between June 2002 and June 2008 a total of 354 consecutive patients with ULMCA stenosis were treated with percutaneous coronary intervention with BMS (53 patients) or DES (301 patients) implantation. A multivariable adjustment was provided in order to account for baseline differences between groups. RESULTS: The average clinical follow-up was 551+/-512 days. Overall, MACE rate was significantly lower in the DES group (16.6% vs 26.4%, P=0.02). The beneficial effect was driven by a reduction of death (6.0% vs 9.4%, P=0.11), MI (2.7% vs 3.8%, P=0.33) and target vessel revascularization after DES implantation (9.0 % vs 15.1%, P=0.11). After correcting for independent predictors of adverse events, the adjusted hazard ratios (HRs) for the risk of mortality and myocardial infarction after DES implantation relative to BMS implantation were 0.99 (95% CIs 0.30-3.21, P=0.98) and 0.59 (95% CIs 0.01-3.45, P=0.56), respectively. The adjusted HR for two-year MACE was 0.50 (95 CIs 0.25-1.02), P=0.056, mainly driven by a statistical significant reduction of TVR (HR 0.30 [95 CIs 0.11-0.82], P=0.018]. CONCLUSIONS: Patients presenting with ULMCA disease, who are treated with DES have a significant reduction in the rate of target lesion revascularization with no increased risk of death or myocardial infarction.

The prevalence of dysphonia and dysphagia in patients affected by immunomediated diseases and the role of psychometric tests.

This cross-sectional investigation examined the prevalence and severity of dysphonia, globus pharyngeus, and dysphagia in patients affected by immunomediated (IM) diseases. Seventy subjects were administered the Voice Handicap Index (VHI) (scale 0-4), Glasgow-Edinburgh Throat Scale (GETS) (scale from 0 to 7) for globus pharyngeus assessment, and modified Swallowing Outcomes After Revised Laryngectomy (SOAL) (scale 0, 1, 2) to test swallowing symptoms. VHI: the mean percentage of answers with a score greater than 1 (corresponding to a frequency of situation's occurrence "sometimes," "almost always," or "always") was 25.7, 26.7, and 44.1% for functional, emotional, and physical groups of sub-items respectively. GETS: the mean percentage of answers with a score ≥ 3 was 60.85%, significantly higher if compared with that of answers with a score < 3 (40.14%). The mean percentages of answers with a score 0-2, 3-4, and 5-7 were 40.1, 16.7, and 43.7% respectively. SOAL: a mean of 57.9% of answers gained a symptomatic score (1 ["a little"] or 2 ["a lot"]) and 41.9%, the score 0. The difference was statistically significant (p < 0.05). The first two most recurrent items with a score 2 ("a lot") were "Do you have a problem swallowing dry food?" (46%) and "Do you have a problem swallowing solid food?" (36%). The study represents the first to describe the globus pharyngeus symptoms in IM population. Moreover, it allows to confirm the recurrence of dysphonia and dysphagia in this type of patients. Particularly, it has been demonstrated that the alteration of swallowing function is related to solid and dry food. The self-assessment questionnaires proved as a useful tool to early detection of dysfunctions in order to avoid further deterioration of quality of life and to prevent serious life-threatening complications.

Activity profile of elite goalkeepers during football match-play.

AIM: The purpose of this study was to analyse the activities of a goalkeeper during a match and to identify the distances covered at different velocities between the first and second halves. METHODS: Sixty-two goalkeepers belonging to 28 teams in the English Premier League were monitored over 109 matches using the Prozone(R) system. All values are averages and standard deviations. Pearson product moment correlation was used to examine selected bivariate correlation. To analyze the differences in averages, the paired Student t-test was used. The analyses were performed using SPSS (v.13.0; SPSS, Inc. Chicago, IL). The significance level was set at P<0.05. RESULTS: Mean total distance covered by the goalkeeper during the match was 5 611+/-613 m. There were no differences between distances covered in the first and second halves. The distance covered at high-intensity was 56+/-34 m, while the distance covered sprinting was 11+/-12 m. The average number of high speed actions was 10+/-6, with a total range between 0 and 40. The goalkeeper walked during 73% of the match, while spending just 2% moving at high-intensity. CONCLUSION: The goalkeeper's physical activity was not as great as that of the field players, but the high-intensity actions carried out will be very decisive in the final result of the match.

Proteases and chronic leg ulcers.

AIM: The aim of this study was to compare the effect of cadexomer on reducing wound surface area of leg ulcers compared to that obtained in a group patients whose ulcers were treated by compression therapy. METHODS: For each ulcer group, wound surface area was calculated at day 0 and after 28 days of treatment: this allowed to calculate the average wound surface area reduction, the percent reduction in wound size, as well as the weekly wound size reduction index. RESULTS: In the cadexomer-treated ulcers the total wound area reduction was 9.67 cm(2)/week, with a weekly wound size reduction index per patient of 0.96 cm(2); in the controls (compression therapy-treated patients) the total wound area reduction was 6.11 cm(2)/week, with a weekly reduction index per patient of 0.61 cm(2). At the end of treatment, in the group of patients whose ulcers were treated with cadexomer ointment the average wound size reduction was 43%, whereas in the control-treated patient group the average wound size reduction was 28%. CONCLUSION: These data suggest that cadexomer can play an important role in the healing of chronic leg ulcers.

Two novel Ehrlichia strains detected in Amblyomma tigrinum ticks associated to dogs in peri-urban areas of Argentina.

The aim of this work was to describe two novel strains of Ehrlichia associated to Amblyomma tigrinum from Argentina. Molecular detection of agents belonging to the family Anaplasmataceae was performed targeting three different loci: 16S rRNA gene, dsb gene and a fragment of groESL heat shock operon. The results have shown that two different strains of Ehrlichia sp. associated to A. tigrinum are circulating in peri-urban areas of Argentina. The Ehrlichia strain detected in ticks from San Luis Province, named as Ehrlichia sp. strain San Luis, is closely related to the Ehrlichia chaffeensis. The novel Ehrlichia strain detected in Córdoba Province, named as Ehrlichia sp. strain Córdoba, is phylogenetically related to three Ehrlichia strains from Brazil, two of them isolated from wild carnivorous and the third one isolated from horse. Even though Ehrlichia sp. strain Córdoba was clustered with the three Ehrlichia strains from Brazil, the genetic similarity was too low to consider them as the same taxonomic entity. Blood samples of dogs were positive to Anaplasma platys. The association of these two novel strains with A. tigrinum has epidemiological relevance because adult stages of this tick species are common parasite of dogs in rural and peri-urban areas and they are aggressive to humans. The presence of these two novel Ehrlichia strains implies a potential epidemiological risk in Argentina because the species of the genus Ehrlichia are known to be pathogenic to both domestic mammals and humans.

Enzymatic debridement: is HA-collagenase the right synergy? Randomized double-blind controlled clinical trial in venous leg ulcers.

OBJECTIVE: The aim of this study is to evaluate the efficacy and safety of a new ointment containing Hyaluronic Acid and collagenase from non-pathogenic Vibrio alginolyticus. PATIENTS AND METHODS: Double blind, multicenter, controlled clinical trial (no. ISRCTN71239043) conducted to demonstrate the superiority of Hyaluronic Acid-Collagenase applied once a day over placebo in mean reduction of devitalized/fibrinous/slough tissue after 15 days of treatment. 113 patients with venous ulcers were enrolled and randomized to receive active treatment therapy or vehicle preparation. Both arms also received compression therapy. Subjects were assessed at baseline and at 4 different clinical study visits up to a maximum of 30 days. Outcome measures included mean percentage debridement evaluated by digital planimetry, pain during change of dressing measured on a visual analogue scale and adverse event assessment for tolerance. RESULTS: After 15 days the debridement rate in the active group was 67.5% compared to 59% in the placebo group (p = 0.0436). A significantly higher number of patients in the treatment group achieved 100% debridement by day 15 (p = 0.0025) than in the control group, and a higher percentage also demonstrated complete debridement at every other time point. Pain perception was similar in both groups with low levels during medication. No differences in tolerance were observed between groups. CONCLUSIONS: Chronic venous ulcers treated with this novel compound of Hyaluronic Acid and collagenase resulted in a significantly higher debridement rate at Day 15 vs. the control group. Hyaluronic Acid-Collagenase was well tolerated and a low degree of pain was perceived during dressing change. The preparation of 0.2% of Hyaluronic acid-collagenase shows significant benefits in the management of chronic ulcers.

Wastewater contamination in Antarctic melt-water streams evidenced by virological and organic molecular markers.

Human activities in the Antarctica including tourism and scientific research have been raised substantially in the last century with the concomitant impact on the Antarctic ecosystems through the release of wastewater mainly from different scientific stations activities. The aim of this study was to assess the wastewater contamination of surface waters and sediments of three melt-water streams (11 sites) by leaking septic tanks located in the vicinity of the Uruguayan Scientific Station in the Fildes Peninsula, King George Island, Antarctica, during summer 2015. For this purpose, we combined the analysis of fecal steroids in sediments by using gas chromatography and six enteric viruses in surface waters by quantitative and qualitative PCR. Coprostanol concentrations (from 0.03 to 3.31µgg-1) and fecal steroids diagnostic ratios indicated that stations C7 and C8 located in the kitchen stream presented sewage contamination. Rotavirus was the only enteric virus detected in five sites with concentration ranging from 1.2×105gcL-1 to 5.1×105gcL-1 being three of them located downstream from the leaking AINA and Kitchen septic tanks. This study shows for the first time the presence of both virological and molecular biomarkers of wastewater pollution in surface waters and sediments of three melt-water streams in the vicinity of a scientific station in the Antarctica. These results highlight the importance of the complementation of these biomarkers in two different matrices (surface waters and sediments) to assess wastewater pollution in an Antarctic environment related to anthropogenic activities in the area.

X-ray structure of Escherichia coli pyridoxine 5'-phosphate oxidase complexed with FMN at 1.8 A resolution.

BACKGROUND: Escherichia coli pyridoxine 5'-phosphate oxidase (PNPOx) catalyzes the terminal step in the biosynthesis of pyridoxal 5'-phosphate (PLP), a cofactor used by many enzymes involved in amino acid metabolism. The enzyme oxidizes either the 4'-hydroxyl group of pyridoxine 5'-phosphate (PNP) or the 4'-primary amine of pyridoxamine 5'-phosphate (PMP) to an aldehyde. PNPOx is a homodimeric enzyme with one flavin mononucleotide (FMN) molecule non-covalently bound to each subunit. A high degree of sequence homology among the 15 known members of the PNPOx family suggests that all members of this group have similar three-dimensional folds. RESULTS: The crystal structure of PNPOx from E. coli has been determined to 1.8 A resolution. The monomeric subunit folds into an eight-stranded beta sheet surrounded by five alpha-helical structures. Two monomers related by a twofold axis interact extensively along one-half of each monomer to form the dimer. There are two clefts at the dimer interface that are symmetry-related and extend from the top to the bottom of the dimer. An FMN cofactor that makes interactions with both subunits is located in each of these two clefts. CONCLUSIONS: The structure is quite similar to the recently deposited 2.7 A structure of Saccharomyces cerevisiae PNPOx and also, remarkably, shares a common structural fold with the FMN-binding protein from Desulfovibrio vulgaris and a domain of chymotrypsin. This high-resolution E. coli PNPOx structure permits predictions to be made about residues involved in substrate binding and catalysis. These predictions provide testable hypotheses, which can be answered by making site-directed mutants.

Ocular Munchausen syndrome resulting in bilateral blindness.

PURPOSE: Münchausen syndrome is a factitious disorder in which patients knowingly harm themselves for subconscious psychological reasons in order to be hospitalized. Recognition of this psychopathology is important, to prevent potentially severe eye damage. Ocular Münchausen syndrome is uncommon. The authors describe an elderly woman with recurrent, probably self-induced, ocular trauma leading to bilateral blindness. The authors are unaware of any previously reported cases of Münchausen syndrome resulting in bilateral blindness and occurring in old age. CASE REPORT: A 73-year-old woman was first seen in 1991 with a closed-globe injury to the right eye, apparently following a household fall. Physical examination showed no sign of extraocular trauma. Right visual acuity was 20/30 after 2 months. She was readmitted in May 2003 with left globe rupture, allegedly following a domestic fall. No extraocular trauma was found. She developed ocular phthisis 6 months postoperatively. The patient was admitted again in February 2004 with right globe rupture, following another alleged domestic fall. Physical examination showed no sign of extraocular trauma. Right visual acuity was 20/400 2 months postoperatively. Psychiatric evaluation revealed Münchausen syndrome. Psychotherapy was prescribed, but refused by her family. CONCLUSIONS: Diagnosis of Münchausen syndrome is difficult to make in the ophthalmic department. Münchausen patients have little or no ability to control their self-destructive behavior. A sympathetic and supportive approach is therefore required and these patients should be urgently referred to a psychiatrist with experience in factitious disorders. Even with psychotherapy, which is often refused, the prognosis remains poor.