Design and evaluation of an imaging spectrophotometer incorporating a uniform light source.

Accounting for light that is diffusely scattered from a surface is one of the practical challenges in reflectance measurement. Integrating spheres are commonly used for this purpose in point measurements of reflectance and transmittance. This solution is not directly applicable to a spectral imaging application for which diffuse reflectance measurements are desired. In this paper, an imaging spectrophotometer design is presented that employs a uniform light source to provide diffuse illumination. This creates the inverse measurement geometry to the directional illumination/diffuse reflectance mode typically used for point measurements. The final system had a spectral range between 400 and 1000 nm with a 5.2 nm resolution, a field of view of approximately 0.5 m by 0.5 m, and millimeter spatial resolution. Testing results indicate illumination uniformity typically exceeding 95% and reflectance precision better than 1.7%.

Buoyant plumes from solute gradients generated by non-motile Escherichia coli.

The effect of hydrodynamic mixing in bacterial populations due to bacterial chemotaxis is a well-described phenomenon known as bioconvection. Here we report the observation of buoyant plumes that result in hydrodynamic mixing, but in contrast to bioconvection the plumes form in the absence of bacterial motility. We propose that the buoyant flow originates from solute gradients created by bacterial metabolism, similar to solute-induced buoyant flow around growing protein crystals. In our experiments, metabolically-active non-motile Escherichia coli were layered along the bottom of flat-bottomed containers. The E. coli consumed glucose in the medium creating a lighter fluid beneath a heavier fluid. The situation is an example of Rayleigh-Taylor instability, in which a lighter fluid pushes on a heavier one. We developed a numerical model to study the effect of E. coli nutrient consumption and by-product excretion on extracellular solute gradients. The model solutions showed reduced-density fluid along the bottom of the fluid domain leading to buoyant plumes, which were qualitatively similar to the experimental plumes. We also used scaling analyses to study the dependence of plume formation on container size and cell size, and to investigate the effect of reduced gravity, such as the microgravity conditions encountered during spaceflight.

Exposure to increased pressure or hyperbaric oxygen suppresses interferon-gamma secretion in whole blood cultures of healthy humans.

This study examines the effects of hyperoxia, increased atmospheric pressure, and hyperbaric oxygen on cytokine synthesis. Five healthy volunteers were exposed to 90 min of room air, 100% oxygen, 10.5% oxygen at 2 atm abs, or 100% oxygen at 2 atm abs (HBO2). All subjects were blinded and randomly exposed to each of the 4 conditions. Immediately before entering the chamber, immediately after exposure, and 3 and 24 h later, blood was drawn and stimulated ex vivo with phorbol myristate acetate (PMA) and phytohemagglutinin A (PHA). Since lymphocytes are the primary source of PMA/PHA-induced interferon-gamma (IFN-gamma), these results were expressed as IFN-gamma production per 10(6) lymphocytes. Following the HBO2 exposure, PMA/PHA-stimulated lymphocytes released 51% less IFN-gamma than cells obtained before the exposure. This suppression persisted for 24 h following HBO2 (P < 0.05). Surprisingly, increased atmospheric pressure alone also inhibited IFN-gamma secretion (P < 0.05). Room air and hyperoxia alone had no significant effect upon IFN-gamma release. HBO2's anti-inflammatory effect may, in part, be due to inhibition of IFN-gamma release.

The drug-resistant pneumococcus: clinical relevance, therapy, and prevention.

Streptococcus pneumoniae has been known for > 100 years as the most important bacterial pathogen of the respiratory tract in adults and children. In recent years, the pneumococcus has begun to exhibit increasing resistance to antimicrobial agents. Because of the huge number of infections caused by this organism, the development of resistance has changed the approach to many infectious disease problems, particularly with regard to empiric antibiotic therapy and prophylaxis. In our review of the antibiotic-resistant pneumococcus, we review the microbiologic basis for resistance, risk factors for and clinical relevance of infection by a resistant organism, and infection control measures.

Managing by numbers: using outcome measures in the NHS.

The paper explores the literature concerning outcome measures used in health services. The need to measure outcomes subsequent to encounters with health services has been identified and occurs as a result of the current "value for money" approaches being used within the NHS. Provider units are required to establish the effects which interventions have had on the health of each individual using their services, despite the fact that definitions of health outcomes used by both professionals and managers are problematic. It is suggested here, however, that outcome measures which answer all requirements will remain elusive, and their effectiveness will vary according to the circumstances of their generation and use. Moreover, the very use of outcome measures as management tools can lead to a subversion of the meaning which led to their selection in the first place. Managing by (outcome measure) numbers is not a realistic way forward.

Aetiologies and outcomes of wounds in an outpatient programme.

This study reviewed the records of all new patients seen in an outpatient wound-care programme during a six-month period. Most of the 115 patients were referred by physicians in internal medicine or family practice (48%) or surgeons (39%); 101 had a wound (88%). Of the 92 who had their wound measured at the time of their first clinic visit, 72 (78%) had their largest wound located on a lower extremity and 40% of all lower extremity wounds were on the feet. Wounds were most frequently due to pressure (36%), venous insufficiency (16%), diabetic neuropathy (16%), or arterial insufficiency (13%). Within 12 months of their initial presentation, wound closure was documented in 35 of the 92 patients (38%). Of the four most common aetiologies, the healing rate was highest in wounds attributable to venous insufficiency (67%) (p < 0.02).

Outpatient parenteral antibiotic therapy in the management of community-acquired lower respiratory infections.

Within the past several years, the decision to employ outpatient parenteral antibiotic therapy (OPAT) is driven by adequacy of insurance, availability of appropriate resources within the community, and the clinical stability of the patient. Current dogma is that virtually any diagnosed disease can be treated outside the hospital, provided the former criteria are met. The decision to utilize OPAT is complex and involves a number of decision points that relate to the patient, the disease and pathogen, the antibiotic, and the facilities available in the community. This article discusses the decision-making process to utilize OPAT or hospitalization for community-acquired lower respiratory infections.

A method to track surgical site infections.

We present an approach to assessing the impact of surveillance for surgical site infections and providing feedback to surgeons on their progress, as part of continuous quality improvement. Adjusting for patient risk factors using the Standardized Mortality Ratio, there was a marked decrease over time in both SMR (1.3 to 0.27) and crude infection rates (32 to 10 per thousand operations per year). These declines cannot be explained by decreased length of hospital stay.

Aetiologies and outcomes of wounds in an outpatient programme.

This study reviewed the records of all new patients seen in an outpatient wound-care programme during a six-month period. Most of the 115 patients were referred by physicians in internal medicine or family practice (48%) or surgeons (39%); 101 had a wound (88%). Of the 92 who had their wound measured at the time of their first clinic visit, 72 (78%) had their largest wound located on a lower extremity and 40% of all lower extremity wounds were on the feet. Wounds were most frequently due to pressure (36%), venous insufficiency (16%), diabetic neuropathy (16%), or arterial insufficiency (1 3%). Within 12 months of their initial presentation, wound closure was documented in 35 of the 92 patients (38%). Of the four most common aetiologies, the healing rate was highest in wounds attributable to venous insufficiency (67%) (p < 0.02).

Hereditary ataxia with sensory neuronopathy: Biemond's ataxia.

We report the case of a man with late-onset hereditary ataxia and sensory loss. Three of his sisters were affected by a similar disorder; to date no other members of his family have developed symptoms. The clinical features of this family are similar to a rare form of autosomal dominant hereditary ataxia, recently classified as SCA4. Postmortem findings indicate that this syndrome is marked by degeneration of cerebellar Purkinje cells, dorsal root sensory ganglion neurons, and the ascending posterior columns. Similar clinical and pathologic findings were reported by Biemond in 1954.

Why the NHS should abandon the search for the universal outcome measure.

This paper considers the use of outcome measures in the British National Health Service (NHS). Measuring outcomes is a major conceptual and practical problem. Many different measures are currently available yet no consensus has been reached on which should be preferred over others, or about which should take priority when they conflict. Some currently used measures are described, the relationship between these measures and the measured activities are discussed, and fundamental problems with both the measures and their use are revealed. It is shown that however assiduous the search, the 'perfect' outcome measure will always remain elusive.

Involving patients in the provision of community care: a change in philosophy.

The National Health Service (NHS) has many different kinds of professionals and managers working underneath its large umbrella: non-clinical managers administer the work of health-care professionals, who in turn are concerned with the management of patients' treatments. Delivery of health-care services involves the managers and professionals working together to achieve a service that is good for, and acceptable to, patients. A change in the philosophy of the NHS is indicated by the growing acceptance, by both managers and professionals, of the necessity to elicit the views of patients (i.e. the expectations and perceptions of service users) and to incorporate these views into the planning and implementation of services. Discusses one such attempt to elicit the perceptions of service users, and reports on the preliminary findings of a patient-centred audit which has been undertaken in Southend Community Care Services NHS Trust. Discusses the effects that the audit has had on the chiropody services in Southend, for both non-clinical managers and health-care professionals, in order to highlight the usefulness of the approach.

Outpatient treatment of community-acquired pneumonia in adults.

Most adults with community-acquired pneumonia are treated as outpatients. Despite this, the majority of studies regarding community-acquired pneumonia have been in hospitalized patients only and may not be applicable to an ambulatory population. This review critically examines the literature regarding the diagnosis, cause, appropriate patient selection, and treatment of nonhospitalized adults with community-acquired pneumonia, including human immunodeficiency virus-infected individuals. English-language articles on oral antibiotic trials for community-acquired pneumonia, obtained from a MEDLINE search from 1966 to the present, are reviewed. Etiologic diagnosis is helpful in determining appropriate outpatient treatment for community-acquired pneumonia, and usually requires only sputum Gram's stain analysis. Viral, mycoplasmal, and chlamydial agents are among the most common pathogens encountered in individuals treated as outpatients, although much variability exists. Many oral antibiotic trials for community-acquired pneumonia have been published, but shortcomings in study design limit their clinical applicability. A treatment algorithm is offered, using the best available data.

Community-acquired bacteremias from tunneled central intravenous lines: results from studies of a single vendor.

Tunneled central intravenous catheters are a common method for rendering prolonged outpatient intravenous therapy. Their safety, however, has not been well studied. We conducted a retrospective evaluation of bacteremias associated with tunneled central intravenous catheters managed by a single home health care vendor during a 1-year period. All catheters were inserted in the operating room under sterile conditions. To calculate total line days, the dates of catheter insertion and removal were obtained from either the hospital operating room or the home health care agency. Catheter care was conducted according to written protocols. Total line days were calculated. Community-acquired bacteremia (defined as bacteremia occurring more than 6 days after the patients' discharge from the hospital) was determined from records available in the infection control department. Sixty-eight patients received intravenous therapy from the vendor during the 1-year study period. Total line days were 5548 (median 52 days/patient). Eleven episodes of bacteremia occurred in five patients, providing an incidence density rate of 2.0 infections/1000 catheter days. The most frequent bacteria encountered were Staphylococcus epidermidis (five), Klebsiella pneumoniae (two), and Acinetobacter calcoaceticus var anitratus (two). Median time to bacteremia was 103 days. Two patients, both younger than 4 years, accounted for seven of the infections; both had short-bowel syndrome. On the basis of historical comparisons, outpatient intravenous therapy appears to be associated with a lower risk of bacteremia than in-hospital therapy. These data can provide quality improvement information and may be a means for comparing home infusion therapy vendors.

Laparoscopic hernia repair: a rural perspective.

Laparoscopic hernia repair has been used successfully to repair inguinal as well as some ventral, incisional, and umbilical hernias. The laparoscopic approach is favored by patients because they experience little, if any, postoperative pain and enjoy a rapid return to unrestricted activity. We repaired 84 hernias in 61 patients from March 1991 to December 1992. All patients were treated by the author in rural west-central Minnesota hospitals, each of which has 30 beds or less. A unique preperitoneal patch design was used, and a novel technique for the dissection of an indirect hernia sac was developed. The patient population treated was older than that reported in other series, with an average age of 55 and a median age of 61 years. Based on postoperative interviews, 95% of the patients reported being satisfied with the procedure and their outcome. All ten patients who had also experienced traditional hernia surgery preferred the laparoscopic repair. They cited less postoperative pain and a quicker return to full activity as the main reasons for their preference. Of the three patients who had a recurrence of their hernia, two have had a repeat laparoscopic hernioplasty without subsequent recurrence. The third patient has indicated that he plans to have his recurrent hernia repaired laparoscopically again. One hundred percent of the patients indicated that they would choose to have a laparoscopic hernia repair should they need another hernia repaired in the future.

Who is the NHS for?

The immediate, common sense answer to the question, "Who is the NHS for?" would obviously be, "The patients who use it". This may well be the fundamental purpose of the NHS, yet it would appear that differing views of how this is to be achieved contribute to a misreading between stakeholders of each others' remit. The different positions taken by the two most important NHS stakeholders, the professional clinicians and the administrative managers, affect their definitions of, and therefore their attitudes to their own contribution to the purpose of the NHS. Suggests that before priorities in health care can be considered and discussed, let along be set, consensual agreement needs to be reached concerning the views of professional clinicians and managers of ways of achieving their vision of who the NHS is for.

Carcass and meat sensory traits of steers finished on fescue and clover, summer forage, or for different periods in drylot.

During a 3-yr period 184 steers were allotted to five treatment groups. Group 1 steers were pastured on fescue-clover and slaughtered in the spring at approximately 540 d of age. Group 2 steers were pastured on fescue-clover then placed on summer pasture regimens and slaughtered at approximately 620 d of age. Group 3 steers were treated the same as Group 2 then placed in the drylot for 45 d. Group 4 steers were treated the same as Group 2 steers then placed in the drylot for 75 d. Group 5 steers were placed in drylot after weaning and conditioning and were slaughtered at endpoints that corresponded with those for Group 3. Steers selected for slaughter at each endpoint were those evaluated to have reached the most optimum slaughter weight and finish by project personnel. Carcasses of steers from fescue-clover and summer pasture had lower yield grades and a lower quality grade than carcasses of steers from drylot (P < .05). Carcasses of steers from fescue-clover and summer pasture had a more yellow fat covering than carcasses of steers that received a concentrate (Treatments 3, 4, and 5, P < .0001). Fescue-clover- and summer pasture-fed steers had a higher percentage of lean and a lower percentage of fat in the 9-10-11th rib section than did steers that received concentrate (P < .005). Chemical analysis of the lean tissue of the 9-10-11th rib section indicated that summer pasture-fed steers had a lower percentage of ether extract and higher percentage of moisture than the lean tissue from steers that received concentrate (P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)