Treatment of experimental Salmonella typhimurium infection in mice with lomefloxacin

To evaluate the difluorinated quinolone lomefloxacin in murine typhoid, mice were inoculated intraperitoneally with the LT-2 strain of Salmonella typhimurium and treated with graded doses of the drug given once daily by an orogastric needle. Treatment with lomefloxacin for seven days reduced mortality with a 50% effective dose of 2.5-7.8 mg/kg/day. When given once daily for three days, doses greater than or equal to 5 mg lomefloxacin/kg/day caused significant reductions in splenic counts of S. typhimurium and prevented the inflammatory response to infection in the spleen.

Evaluation of patient, physician, nurse, and family attitudes toward do not resuscitate orders

We investigated attitudes toward resuscitation by interviewing 97 competent patients classified as do not resuscitate, 60 physicians, 80 family members, and 84 nurses. In addition, 58 family members of incompetent do not resuscitate patients were interviewed. Interview patients were generally elderly, female widows with a diagnosis of malignancy. The majority (66%) preferred that their medical decision making be shared with the physician and/or family. Only 38 patients (39%) could correctly define a "living will." After hearing the definition, 59 patients (61%) thought it was a good idea to ask noncritically ill patients at the time of hospital admission, if they had a living will. Fifty-six patients (58%) said they had discussed resuscitation with their physician, whereas 44 physicians (73%) said they had discussed it with the patient. Only 53 patients (55%) said that they thought their physician understood their wishes. Sixty-five patients (67%) wanted involvement in resuscitation decisions. Forty-eight patients (49%) offered "quality of life" reasons for not wanting to be resuscitated. Sixty-four patients (66%) did not think discussing resuscitation was cruel and insensitive. Eighteen physicians (30%) said they were uncomfortable discussing resuscitation with patients. We recommend introducing the topic of resuscitation early in the patient-physician relationship before diminished competency occurs.

Causes of death and the histopathologic findings in fatal shigellosis

Thirty-seven children (median age, 2 years) with shigellosis in Bangladesh were subjected to postmortem examination to determine causes of death and the spectrum of intestinal histopathology. Infecting species were: Shigella dysenteriae 1, 7 cases; S. dysenteriae 2, 2 cases; Shigella flexneri, 23 cases; Shigella boydii, 4 cases; and mixed infection with Shigella boydii and Shigella sonnei, 1 case. Complicating conditions detected before death included malnutrition in 25 cases, pneumonia in 11 cases and septicemia in 8 cases. In all 37 cases the colon showed gross colitis, consisting of mucosal erythema and edema; superficial ulcerations were visible in 15 cases. Microscopically in the colon the lamina propria showed inflammatory cellular infiltration in 27 cases and crypt abscesses were present in 22 cases. In 9 cases each there were colonic glands in the submucosa and branching of colonic crypts, indicating increased regenerative activity of crypt cells. Severe lesions were mucosal denudation and deep ulceration in 15 cases with a pseudomembrane in 7 and pseudopolyposis in 2 of these patients. The most common underlying cause of death was colitis, whereas the most common immediate and associated causes were, respectively, septicemia and pneumonia. These results indicated that fatal childhood shigellosis results from severe colitis, often complicated by septicemia and concomitant malnutrition and pneumonia.

Evaluation of the do not resuscitate orders at a community hospital

Demographic, medical, and outcome characteristics for 821 do not resuscitate (DNR) patients were compared with 300 age- and sex-matched control patients, and with 230 patients for whom cardiopulmonary resuscitation had been performed. Do not resuscitate patients were more likely to be female and older than cardiopulmonary resuscitation patients and to have a child as next of kin. Although DNR patients in intensive care units had comparable illness levels before and at the time of the order, treatment levels were reduced when the order was written. In general, DNR patients received more nursing care than other patients. Hospital mortality was 59.8% for DNR, 83.9% for CPR, and 1.7% for control patients. We identified diagnosis, prior activity, hospital unit, and employment status as predictors of DNR. According to documentation, 20% of patients participated in the DNR decision. Introduction of a DNR progress note form significantly improved documentation of the DNR process, but further efforts to improve DNR practice and patient participation are recommended.

Hazard from weapons impulses: histological and electrophysiological evidence

Current methods of rating the hazard of weapons impulses for the ear have recently been challenged by electrophysiological data from experiments with animal ears which indicate that the hazard from low-frequency impulses is much lower than the hazard from higher frequency impulses (Dancer et al., 1981; Price, 1986b). To supplement these data, histological data are reported here for 51 cats that were exposed on one occasion to either rifle or howitzer impulses at peak pressures from 145 to 155 dB or 153 to 166 dB, respectively. Histological procedures (scanning electron and light microscopy) were carried out over 2 months after the exposure and after electrophysiological measures had been made. For both types of impulse the losses tended to be in the middle of the cochlea in focused lesions, even though the spectral peaks of the acoustic stimuli had been at about 80 Hz (howitzer) and 1000 Hz (rifle). Outer hair cells were more susceptible than the inner hair cells and interindividual differences in effects were large. Furthermore, the two impulse sources were equally hazardous when the peak pressure of the rifle impulse was lower than the peak pressure of the howitzer impulse by about 9 dB. In terms of A-weighted energy, the exposures were equally hazardous when the rifle exposure contained about 35 times less energy than the howitzer exposure. The histological data are thus consistent with the electrophysiological data, which indicate that present standards for impulse noise exposure may overrate the hazard of low-frequency impulses relative to impulses in the midrange.

Micropenis and congenital adrenal hypoplasia

Micropenis is often an early sign of congenital hypopituitarism. It has also been associated with congenital adrenal hypoplasia in infants with anencephaly and pituitary agenesis. This report is on two infants with micropenis and congenital adrenal hypoplasia. One presented with a similar clinical course and postmortem findings to previously reported cases of adrenal hypoplasia and pituitary agenesis. The other patient represents the first reported case of an infant with micropenis and congenital adrenal hypoplasia in the absence of pituitary agenesis. The histologic patterns of adrenal hypoplasia, as well as the etiologic and clinical implications of its association with micropenis, are discussed.

The interaction of alpha thalassaemia and sickle cell-beta zero thalassaemia

The effects of alpha thalassaemia on sickle cell-beta zero thalassaemia have been studied by comparing haematological and clinical features in four subjects homozygous for alpha thalassaemia 2 (2-gene group), 27 heterozygotes (3-gene group), and 55 with a normal alpha globin gene complement (4-gene group). Alpha thalassaemia was associated with significantly higher haemoglobin levels and lower reticulocyte counts independent of the presence of splenomegaly. Contrary to expectation, alpha thalassaemia was associated with small but significant increases in mean cell volume and mean corpuscular haemoglobin concentration. Splenomegaly at age 5 years and episodes of acute splenic sequestration were significantly more frequent in the 4-gene group. There were no significant differences in painful crises, acute chest syndrome, or other clinical features.

Resource-based relative values. An overview

Studies have been conducted over the past decade to develop a Resource-Based Relative Value Scale (RBRVS) for physicians' services. Policymakers view an RBRVS as a potential tool to pay physicians. The Physician Payment Review Commission, under a congressional mandate, has endorsed the general concept of a fee schedule based on resource costs for physician payment under Medicare. In this overview article, we present the policy context in which the RBRVS may play a role and describe the approach taken to develop this scale, specifically consultation with clinicians, researchers, and insurers and data gathering, including a national survey of physicians. We discuss underlying elements that are necessary to constructing an RBRVS, each of which is described more fully in subsequent articles: measuring the work (intraservice work) of performing medical services and procedures, estimating preservice and postservice work, comparing work across specialties, measuring practice costs, extrapolating from surveyed services, and establishing an RBRVS for evaluation/management services and for invasive procedures. Overall results are presented in a companion article.

A method for estimating the preservice and postservice work of physicians' services

The goal of the Resource-Based Relative Value Scale is to measure the resource costs of physicians' services, or, more centrally, the physicians' total work. This article describes the estimation of relative values for physicians' work before and after the performance of a service (preservice and postservice work). For methodological and practical reasons, we could not obtain direct ratings of preservice and postservice work except for a few services. We therefore developed a systematic process to estimate preservice and postservice time and rate of work per unit of time. Then time and work per unit of time were multiplied to estimate work. The major finding of our investigation is that preservice and postservice work make up a substantial portion of total work. The typical percentages of total work accounted for by preservice and postservice work range from 26% and 33% for imaging services and evaluation and management services, respectively, to 46% for invasive services performed in a hospital inpatient setting.

Measurement and analysis of intraservice work

The work that physicians perform represents a major resource input to medical services and procedures. In this article we describe the concepts of work and its dimensions, as well as the methods developed to measure them. We also describe the design and results of a national probability survey of physicians in 18 specialties. We present the results--estimated values of work and its dimensions--for selected services. Our findings indicate that physicians can give reliable and valid ratings of work and that we can model this work as a function of four dimensions: time, mental effort and judgment, technical skill and physical effort, and stress. Analyzing the complex functional relationship between work and these four dimensions shows that all four dimensions are important and statistically significant in predicting work. Time is a more important dimension in predicting work for medical specialties than for surgical specialties, with the estimated regression coefficients between .3 and .5 and .2 and .3, respectively. In contrast, technical skill is a more important dimension in predicting work in surgical specialties than for medical specialties, with the estimated regression coefficients between .3 and .5 and .2 and .3, respectively. Finally, we found that an exponential equation of the four dimensions precisely describes total work.

Cross-specialty linkage of resource-based relative value scales. Linking specialties by services and procedures of equal work

This article describes methods used to combine into a common scale resource-based relative values from separate specialties. The key to producing a common scale is identifying pairs ("links") of services from different specialties that require approximately equal amounts of intraservice work. We distinguished two kinds of pairs of link services, those judged to be the same and those judged to be equivalent, usually within a narrow category of medical activity. Working with a cross-specialty panel of physicians and with data on time factors from a national survey, we selected sufficient links to connect each specialty to others by at least four links. We then used the weighted least-squares method to locate all the links optimally on a single, common scale. Analyses of the accuracy of this scale showed that the typical disagreement between specialties about where to locate the intraservice work of a given service was only 7%. Other analyses showed that the accuracy of the common scale was not sensitive to different classes of links.

Relative cost differences among physicians' specialty practices

Practice costs, defined as those costs of medical practice that exclude the physician's own time and effort, represent a substantial portion of the resources necessary to perform a service. In this article we describe the development of the practice cost index used in constructing the Resource-Based Relative Value Scale (RBRVS). We derived the practice cost index value for each specialty, using specialty-specific practice costs and gross revenue data. The index values for all other specialties are standardized to the value for general surgery, and these are used to adjust the resource-based relative values for services performed by each specialty; in this way, the RBRVS incorporates practice cost variations. The data used in the construction of the practice cost index are the 1983 Physician Practice Cost and Income Survey data, adjusted to reflect the relative levels of 1986 professional liability insurance. Our findings show that among most specialties, the range of relative difference in practice costs as a percentage of gross revenue is approximately 15%. Four specialties fall outside this range: pathology, psychiatry, rheumatology, and orthopedic surgery. We discuss problems with the available data on practice costs as these relate to their use in the RBRVS and conceptual issues in applying practice costs to the construction of the RBRVS.

Results and policy implications of the resource-based relative-value study

The resource-based relative-value scale (RBRVS) is a measure of relative levels of resource input expended when physicians produce services and procedures. It is a function of the physician's work input, the opportunity cost of specialty training, and the relative practice costs for each specialty. This paper presents resource-based relative values (RBRVs) for selected procedures of four major specialties--family practice, internal medicine, general surgery, and thoracic and cardiovascular surgery. We compare RBRVs with current charges and find several general patterns. Invasive procedures are typically compensated at more than double the rate of evaluation-and-management services, when both consume the same resource inputs. Imaging and laboratory procedures fall between invasive and evaluation-and-management services. We analyze the financial implications of the RBRVS by developing a simple model and simulating the effects of an RBRVS-based fee schedule on physicians' revenues in various specialties. We use Medicare data to perform the simulation under the "budget-neutral" assumption. Results show that an RBRVS-based fee schedule affects specialties differently. The average family practitioner could receive 60 percent more revenue from Medicare, whereas the average ophthalmologist could lose 40 percent of current revenues. The effects on other specialties fall between these two.

Varicella optic neuritis

A 14-year-old girl developed severe bilateral optic neuritis 1 week after the onset of chickenpox. Though previous case reports state that complete recovery is the rule, this child had a persistent decrease in visual acuity in the right eye and loss of color vision and defects in visual fields in both eyes.

Quantitative analysis of the tomographic thallium-201 myocardial bullseye display: critical role of correcting for patient motion

Single photon emission computed tomography (SPECT) myocardial 201TI imaging appears to offer major improvements over planar imaging. Quantitative analysis of the 201TI images appears to offer major advantages over subjective analysis in planar imaging, but the three-dimensional data available in SPECT images requires special approaches to analysis and display. Thus the myocardial "bullseye" display was developed to summarize and analyze the three-dimensional images of the left ventricle in two dimensions. The relative 201TI distribution to each region of the left ventricle of an individual patient can be displayed as the number of s.d.s away from normal that the region falls. We found that patient motion during the 22 min required for SPECT imaging appeared to produce artifactual defects. Thus, computer programs were developed to quantitate motion between consecutive frames of a [201TI] SPECT myocardial imaging study, simulate nonreturning vertical motion in normal patients, and correct the acquired data for motion. Motion as small as 0.5-1.0 pixel (3-6 mm) in the vertical (axial) direction caused artifactual defects in the quantitative bullseye display that resulted in a false-positive rate of up to 40% for a +1.0 pixel shift. Patient motion of magnitude greater than the threshold value for artifact-production (0.5 pixel) occurred at a rate of 10%, and should be corrected before tomographic reconstruction.

Zulu XX/XX dispermic chimaera from Natal with two populations of red blood cells and patchy skin pigmentation

The chimaera is female and has two children. Her blood contains 99% group O, type AcP:BA, Pep-A:8-2 and 1% group A2B, type AcP:RA, Pep-A:1 red cells. H-, A- and B-transferase activities were demonstrated in her serum. The level of the H enzyme activity is low but is at the lower end of the normal range for group O persons. The levels of the A and B enzymes are also low but are higher than expected in a person with 1% A2B red cells in the blood. The levels of the A and B enzymes indicate that tissues other than the chimaera's haemopoietic tissue carry her genetically A2B cell line and are contributing the corresponding transferases to her plasma. Gross patchy skin pigmentation is present on the upper part of her body. The chimaera has evidently inherited two dissimilar germ nuclei from each parent.

Additives to biological substances. IV--Lyophilization conditions in the preparation of international standards: an analysis by high-performance liquid chromatography of the effects of secondary desiccation

Many International Standards, Reference Preparations and Reference Reagents are routinely prepared by lyophilization in the presence of 'inert' carriers followed by an extensive period of secondary desiccation. In this study we have used high-performance liquid chromatography (HPLC) to analyse the effects of lyophilization and secondary desiccation on initial degradation and subsequent stability of a model protein, insulin. Secondary desiccation was found to promote a reaction of the insulin with a carrier consisting of non-volatile buffer salts and a sugar. Secondary desiccation did not improve the stability of the insulin as determined by accelerated thermal degradation and analysis using the Arrhenius equation. We conclude that careful consideration needs to be given, on a case-by-case basis, to the selection of the procedures for the preparation of International Standards, particularly those ampouled in the absence of carrier proteins and intended for physicochemical analysis such as HPLC.

Use of cross-correlation function to detect patient motion during SPECT imaging

We have developed a procedure to detect patient motion during a tomographic acquisition. The method uses frame-to-frame cross-correlation functions of the summed profiles in the vertical and horizontal directions of the planar images. The quantitative output derived from examination of the variation of the change in the pixel value, corresponding to the maximum of the cross-correlation function at each view, provides an effective and nonsubjective means of performing quality control on the presence and amount of movement during a single photon emission computed tomographic scan. In contrast to cine mode and sinogram display, easy to interpret hard copy can be generated through this procedure.