Bilateral endogenous Serratia marcescens endophthalmitis secondary to endocarditis following cardiac surgery.

INTRODUCTION: Endogenous endophthalmitis is a sight-threatening condition caused by microorganisms crossing the blood-ocular barrier and inducing profound intraocular inflammation. CASE REPORT: A 65-year-old female experienced bilateral loss of vision after developing infective endocarditis as a complication of combined Bentall procedure and coronary artery bypass grafting. She was diagnosed with bilateral endogenous endophthalmitis secondary to Serratia marcescens. Despite aggressive treatment with intravitreal injections of antibiotics and steroids, intensive topical and systemic antibiotic therapy, there was permanent loss of sight in both eyes. CONCLUSION: The case highlights the importance of early recognition of the symptoms and signs of endogenous endophthalmitis in any patient with systemic infection by all clinicians and the necessity of prompt ophthalmological referral if a useful level of vision is to be preserved.

An image-based eyelid lesion management service-evaluation of a pilot.

BACKGROUND/AIMS: Oculoplastics is a predominantly visual specialty and many of the pathologies can be diagnosed based on external appearance. An image-based eyelid lesion management service was piloted to reduce the number of patients who would require outpatient clinic review. The aim of this study was to determine its accuracy and feasibility, both as a hospital-based and community optometrist-based service. If successful, the service was envisaged to significantly reduce the number of patients that require face-to-face (F2F) review, in accordance with current post-COVID-19 principles of social distancing. METHODS: Patients with lid lesions attending an oculoplastics clinic were assessed by consultant oculoplastic surgeons in an F2F consultation (Arm A). The lesions were photographed by a professional clinical photographer (Arm B) and by an optometrist with a handheld digital camera (Arm C). These images were reviewed by independent consultants masked to the outcome of the F2F clinical encounter. Data were collected prospectively including patient demographics, diagnosis, suspicion of malignancy and management. The image-based clinic results were compared to the F2F clinic results. RESULTS: Ninety-five patients were included. Clinical diagnoses were compared for intra-observer variability and substantial agreement was demonstrated between gold-standard F2F clinic visit (Arm A) and Arm B (Ƙ = 0.708) and C (Ƙ = 0.776). There was no statistically significant difference in the rate of discharge and all cases of malignancy were either identified or flagged for F2F review in the image-based arms. CONCLUSION: This pilot demonstrated substantial diagnostic agreement of image-based diagnoses with F2F consultation and image review alone did not miss any cases of malignancy.

Enzymatic methylation of microsomal metabolites of benzo(a)pyrene.

These studies suggest that the microsomal metabolism of benzo(a)pyrene (BP) produces metabolites which can be methylated by the catechol-o-methyltransferase (COMT)/S-adenosylmethionine (SAM) enzyme/donor combination. Induced microsomes converted 12 to 15% of substrate BP to polar products. Approximately 0.06% of substrate BP was recovered as COMT/SAM-reactive substances. In tests for specificity, COMT/SAM was found to react with catechols, but not with dihydrodiols, quinones, a phenol, an epoxide, or 1,4-hydroquinone. Organic extracts of COMT/[14C]SAM incubations with BP were fractionated by high-performance liquid chromatography. The appearance of radiolabeled chromatographic bands required the presence of substrate BP, microsomes, and COMT/[14C]SAM. When the Ames mutagenesis assay was supplemented with COMT/SAM, a 36% reduction was observed in the number of revertant colonies induced by the microsomal oxidation of BP. In contrast, the mutagenic properties of 2-aminofluorene were not affected by COMT/SAM. These observations indicate that COMT/SAM does not generally inhibit mixed-function oxidase activity but rather reacts with substances which are activated by ring oxygenations.

A visual programming environment for bioprocess control.

The paper introduces the use of a visual programming environment (LabVIEW) to program custom control functions for bioprocess research. The time taken for a bioprocess scientist to program new functions compared well with typical times expected for experienced programmers using conventional languages. Experienced LabVIEW programmers will develop applications significantly faster. The package described was flexible, easy to use and was ideally suited to developing new applications for control of bioprocesses. It was demonstrated with the development of a system to control specific growth rate in a fed-batch culture.

Diagnosing influenza: the value of clinical clues and laboratory tests.

OBJECTIVE: Our goal was to determine the utility of clinical clues, white blood cell (WBC) and differential counts, and a rapid antigen test for differentiating influenza from coexistent infectious diseases during influenza epidemics. STUDY DESIGN: Data were collected during 3 consecutive influenza outbreaks over a 2-year period. The information collected included date of onset, symptoms, vaccine status, WBC and differential counts, ZstatFlu test (ZymeTx, Oklahoma City, Ok), and influenza culture. Using culture positivity as the criterion for influenza diagnosis, we compared cases with noncases on each variable independently and by logistic regression. Receiver operating characteristic curves were plotted for WBC count, ZstatFlu, and their combination in an effort to determine the most useful diagnostic strategy. POPULATION: We included consecutive patients presenting to a family practice office with fever, cough, sore throat, myalgia, and/or headache during flu season. OUTCOMES MEASURED: The outcomes were sensitivity, specificity, and other measures of test accuracy. RESULTS: Culture-positive cases could not be reliably distinguished from those that were culture negative using symptoms or vaccination status. Both WBC count and ZstatFlu results discriminated fairly well, and their combination did somewhat better. Differential counts were not helpful. WBC counts above 8000 were associated with a low probability of influenza. The sensitivity and specificity of the ZstatFlu were 65% and 83%, respectively. CONCLUSIONS: Our data suggest that symptoms and vaccine status do not reliably identify patients with influenza. Use of WBC counts and the ZstatFlu test can be helpful. The sequence, combination, and criteria for use of these tests depend on tradeoffs between undertreatment of influenza cases and the overtreatment of noninfluenza cases, and the cost and benefit projections for individual patients.

Incidence of periorbital necrotising fasciitis in the UK population: a BOSU study.

BACKGROUND: Periorbital necrotising fasciitis (PNF) is a devastating infection of subcutaneous soft tissue and underlying fascia causing severe morbidity and even loss of life. Few case reports of PNF exist and there are no prospective epidemiological studies. METHODS: A prospective observational study was undertaken using the British Ophthalmological Surveillance Unit reporting system. Questionnaires were sent to reporting ophthalmologists in the UK seeking cases of PNF over a 2-year period. RESULTS: 30 new cases were confirmed. 16 of the reported cases followed a precipitating event, 9 cases followed trauma and 3 followed surgery. ß-haemolytic Streptococcus A was the causative organism identified in 76%, either alone or with concurrent infection, and antibiotic sensitivities are discussed. Systemic complications occurred in the majority of cases (66.6%), with sepsis and death occurring in 10%. Over 50% of surviving patients had subsequent morbidity, reduced acuity (<6/18) being common. CONCLUSION: PNF is a rare, dangerous condition. This study identified an incidence of 0.24 per 1,000,000 per annum in the UK. ß-haemolytic Streptococcus A is the most common causative organism. Mortality remains a potential outcome, and survivors suffer significant morbidity. Early intravenous antibiotic management with a consensus favouring penicillin and clindamycin combined with debridement.

Observation of the in vivo movement of host keratocytes into donor tissue following corneal graft; a novel technique.

BACKGROUND/AIMS: The cornea is a highly cellular structure that exists in a dynamic state of cell loss, renewal and replacement. The limbus contains corneal epithelial stem cells. The progenitor or stem cell of the keratocyte remains poorly defined. The authors sought to investigate the in vivo movement of corneal stromal and epithelial cells using a chromosome in situ hybridisation (CISH) technique on human tissue. METHODS: Four explanted sex-mismatched human corneal buttons were studied using the CISH technique to identify corneal epithelial and keratocyte cells containing the Y chromosome. Keratocyte identity and lack of infiltrating inflammatory cells were confirmed by immunohistochemistry. The sex mismatch of donor (XX) and host (XY) suggested any identified Y chromosomes cells were of host origin having migrated into the donor tissue. RESULTS: Host corneal epithelial cells were identified in all four buttons, and corneal stromal keratocytes were present in three of the four specimens in the central corneal area. CONCLUSION: Defining the corneal cell movements and the location of the progenitor or stem cells has important clinical implications. This study has successfully used the CISH technique to demonstrate the in vivo centripetal movement of corneal stromal keratocytes and epithelial cells. The CISH technique may allow further investigation of the corneal stromal dynamics using archival tissue.

Factors that influence metaphor comprehension skills in adulthood.

We investigated differences between older and younger adults in interpreting metaphors describing emotions (e.g., "Joe was crashing thunder," meaning that he was angry). Subjects selected emotional interpretations and explained the basis of their selection for 12 metaphors. Twenty-four older and 24 younger adults read metaphors that described emotions. The group performed identically when selecting interpretations, but older adults were more likely to make up stories about the person named in the metaphor to explain the metaphor than were younger adults, who focused on attributes of the metaphoric terms. These findings suggest that observed adult age differences in metaphor comprehension reflect methodological factors and may reflect cognitive style differences.

Closed-loop control of fed-batch cultures of recombinant Escherichia coli using on-line HPLC.

This article describes a fully automated system for the on-line monitoring and closed-loop control of a fed-batch fermentation of recombinant Escherichia coli, and presents two case studies of its used in limiting production of unwanted byproducts such as acetic in fed-batch fermentations. The system had two components. The first components, on-line monitoring, comprised an aseptic sampling device, a microcentrifuge, and HPLC System. These instruments removed a Sample from a fermentor, spun it at high speed to separate solid and liquid components, and then automatically injected the supernatant onto an HPLC column for analysis. The second component consisted of control algorithms programmed using the LabView visual programming environment in a control computer that was linked via a remote components were linked so that results from the on-line HPLC were captured and used by the control algorithm was designed to demonstrate coarse feedback control to confirm the operability of the controller. The second case study showed how the system could be used in a more sophisticated feedings strategy providing fine control and limiting acetate concentration to a low level throughout the fermentation. (c) 1994 John Wiley & Sons, Inc.

The role of the upper airway in contributing to respiratory responses during experimental seizures in piglets.

Recent data demonstrating stimulation of respiration during seizures are at odds with the frequent clinical finding of respiratory impairment in patients with generalized seizures. To determine the role of the upper airway in contributing to these clinical observations, a study was performed in 12 weanling piglets. An arterial catheter and epidural electrodes were placed in ketamine-anesthetized piglets. In intact piglets, all airflow was measured through a snug-fitting nasal mask whereas pressure was measured with a subglottic catheter. Tracheostomized piglets had airflow and pressure measured at the trachea. Seizures were induced with i.v. injections of pentylenetetrazol. Peak inspiratory flow resistance was calculated by averaging three epochs of five to seven consecutive breaths. Epochs of greater than 20 s in duration with a tidal volume of < 10 mL were termed apnea. Apnea was considered central when airway pressure was > -2 cm H2O and obstructive when < -10 cm H2O. After 20 min of untreated seizures, intact piglets had significant respiratory and metabolic acidosis, whereas tracheostomized piglets had significant increases in Ve and mild metabolic acidosis. Apnea and obstruction were observed frequently in intact piglets. Resistance was unchanged during seizures in tracheostomized piglets, whereas a nearly 4-fold increase in inspiratory resistance was observed in intact piglets. We conclude that upper airway patency and resistances are important determinants of respiratory responses during generalized seizures in piglets.

Performance modeling and simulation of biochemical process sequences with interacting unit operations.

Many biochemical processes consist of a sequence of operations for which optimal operating conditions (setpoints) have to be determined. If such optimization is performed for each operation separately with respect to objectives defined for each operation individually, overall process performance is likely to be suboptimal. Interactions between unit operations have to be considered, and a unique objective has to be defined for the whole process. This paper shows how a suitable optimization problem can be formulated and solved to obtain the best overall set of operating conditions for a process. A typical enzyme production process has been chosen as an example. In order to arrive at a demonstrative model for the entire sequence of unit operations, it is shown how interaction effects may be accommodated in the models. Optimal operating conditions are then determined subject to a global process objective and are shown to be different from those resulting from optimization of each separate operation. As this strategy may result in an economic benefit, it merits further research into interaction modeling and performance optimization.