Human granulocytic ehrlichiosis in a renal allograft recipient: review of the clinical spectrum of disease in solid organ transplant patients.

BACKGROUND: Ehrlichiosis is a recently described zoonotic infection with two major expressions: human granulocytic ehrlichiosis (HGE) and human monocytic ehrlichiosis (HME). The organisms associated with HGE and HME have been detected in a tick vector in several regions of United States and cases of ehrlichiosis have been reported in the general population. METHODS: We report a case of HGE in a renal allograft recipient and review the clinical spectrum of disease in solid organ transplant recipients and the epidemiological basis for risk. RESULTS: Our patient demonstrated the typical epidemiological, clinical and laboratory features of human granulocytic ehrlichiosis and responded to treatment with doxycycline. CONCLUSIONS: Human ehrlichiosis should be considered in the differential diagnosis of patients with solid organ transplants, who present with fever and thrombocytopenia. The incidence of ehrlichiosis in the solid organ transplant population is similar to that in the United States general population. As reported in immunocompetent patients, prompt diagnosis and treatment results in the rapid resolution of symptoms in transplanted individuals.

Radiographic analysis of metatarsus primus elevatus: a preliminary study.

The authors investigated the effect of x-ray tube head angulation and central ray direction on the position of the first metatarsal relative to the second metatarsal in the lateral foot radiographic view. This preliminary study shows that these variables may influence the perception of metatarsus primus elevatus in the weightbearing lateral foot radiograph.

In vivo Hahn spin-echo decay (Hahn-T2) observation of regional changes in the time course of oleic acid lung injury.

We studied the time course of changes in the Hahn spin-echo decay (Hahn-T2) in lungs of spontaneously breathing living rats at 1 hour, 3 hours, and 7 days following oleic acid injection. Motion artifacts were minimized by using the motion-insensitive interleaved rapid line scan (ILS) imaging technique. Prior to injury, the lungs exhibited two resolvable exponential Hahn-T2 components. One and 3 hours after injury the decay showed a regionally nonuniform behavior, which was fit with one, two, or three exponential components. The short and medium components increased at 1 and 3 hours after injection. The third, much longer, component is probably due to intraalveolar pulmonary edema. After 7 days the Hahn decay was similar to that observed before injury, probably reflecting resolution of the edema. Our data suggest that Hahn-T2 measurements can be used to characterize the time course and regional distribution of lung injury in living animals.

Clinical consequences of alterations in platelet transfusion dose: a prospective, randomized, double-blind trial.

BACKGROUND: The dose-response relationship for platelet transfusion has become increasingly important as the use of platelet transfusion has grown. STUDY DESIGN AND METHODS: One hundred fifty-eight prophylactic apheresis platelet transfusions were administered to 46 patients undergoing high-dose therapy followed by hematopoietic progenitor cell transplantation in a prospective, randomized, double-blind, multiple-crossover study. Transfusions were administered in pairs, differing only in platelet content. Each pair consisted of a lower-dose platelet component (LDP) and a higher-dose platelet component (HDP) administered in random order to the same patient. LDPs contained a mean of 3.1 x 10(11) platelets (range, 2.3-3.5 x 10(11)), and HDPs contained a mean of 5.0 x 10(11) platelets (range, 4.5-6.1 x 10(11)). Patients with active bleeding and those who were refractory to platelet transfusions were excluded. RESULTS: The mean posttransfusion platelet count increment with LDP was 17,010 per microL, and that with HDP was 31,057 per microL (p<0.0001). Only 37 percent of LDPs resulted in platelet count increments of at least 20,000 per microL, whereas 81 percent of HDPs resulted in increments above this level (p<0.0001). The mean transfusion-free interval with LDP was 2.16 days, whereas that with HDP was 3.03 days (p<0.01). Administration of LDPs was associated with a 39 to 82 percent increase in the relative risk (per day) of requiring subsequent platelet transfusions (p<0.0001). CONCLUSION: As compared to the administration of HDPs, the administration of LDPs for prophylactic transfusion in hematopoietic progenitor cell transplant patients results in a lower platelet count increment, a lower likelihood of obtaining a posttransfusion platelet increment >20,000 per microL, a shorter transfusion-free interval, and a greater relative risk per day of requiring additional transfusions.

Tuberculosis screening in private physicians' offices, Pennsylvania, 1996.

OBJECTIVE: To assess tuberculin skin testing practices of physicians after community-wide screening of 1400 children exposed to a pediatrician with active tuberculosis (TB). DESIGN: A self-administered questionnaire. SETTING: Medium-sized city in eastern Pennsylvania. PARTICIPANTS: Pediatricians and family practitioners seeing pediatric patients. MAIN OUTCOME MEASURES: Percentages of physicians who followed published recommendations for placement and reading of TB skin tests published by the American Academy of Pediatrics (AAP) and the Centers for Disease Control and Prevention (CDC). RESULTS: Questionnaires were completed by 60/80 (75%) physicians. The 60 physicians had practiced a mean of 17 years (range 3-38 years), and only one did not do TB skin testing for pediatric patients. The 59 physicians doing TB skin testing reported routinely tuberculin testing more than 900 children per month. Only 8/59 (14%) physicians followed published guidelines for placement and reading of tuberculin tests. Those physicians screened 158 (17%) of the pediatric patients undergoing TB skin testing in a typical month. CONCLUSION: In this community where a highly publicized TB case prompted massive pediatric screening, most physicians seeing children in private practice do not follow standard TB skin testing guidelines. Increased understanding of how private-practice physicians learn about and decide to use recommended standards are needed if tuberculin tests are to be correctly performed and TB appropriately diagnosed.

Evaluation of transmission of Mycobacterium tuberculosis in a pediatric setting.

OBJECTIVE: To determine the extent of transmission of Mycobacterium tuberculosis to pediatric patients exposed to a pediatrician with smear- and culture-positive pulmonary tuberculosis (TB). METHODS: Clinic billing and hospital admission records were used to identify patients seen during the pediatrician's infectious period. Patients were notified of the potential exposure and were offered screening. RESULTS: A total of 1416 pediatric patients were identified as exposed. Of the 606 who completed screening, 12 (2%) had a skin test result > or = 10 mm, 2 (0.3 had a result 5 to 9 mm, and 592 (98%) had a negative test result (0 to 4 mm). No active TB cases were identified. Of the 14 children with a skin test result > or = 5 mm, 7 were U.S.-born and had no other risk for a positive skin test. The remaining seven had either been exposed to another person with infections TB or were from countries with a high prevalence of TB. CONCLUSION: We found evidence of limited transmission of Mycobacterium tuberculosis in the outpatient pediatric setting. Despite extensive resources dedication, only 43% of exposed children completed screening. In similar situations decision should balance the responsibility to protect children exposed to Mycobacterium tuberculosis with other public health priorities and available resources.

Comparison of calculated and experimental NMR spectral broadening for lung tissue.

NMR lineshapes were calculated for a model of lung, and NMR proton spectra were measured for individual voxels in an excised inflated rat lung. NMR lines for parenchymal lung regions containing alveoli, alveolar ducts, and capillaries were calculated using a computer simulation of the NMR signal from a three-dimensional honeycomb-like structure, a collection of modified Wigner-Seitz cells. These cells were modified by rounding the corners and increasing the thickness of the boundaries to model various degrees of lung inflation and lung water. NMR lineshapes were also calculated for the central or nonparenchymal lung regions containing bronchi and large blood vessels. A comparison of theoretical lineshapes with those measured in individual voxels both in the parenchymal and in the central (largely nonparenchymal) regions in excised rat lungs at an inflation pressure of 30 cm of water shows excellent agreement. These results indicate that the NMR lineshape reflects the underlying lung geometry. This research constitutes the first calculations and measurements of NMR lineshapes in lung. The appendix describes a new method for calculating the magnetic field inside a weakly diamagnetic material of arbitrary shape placed in an otherwise uniform external magnetic field. This new method does not require either solution of simultaneous equations or evaluation of integral expressions.

1993 William J. Stickel Silver Award. Anatomical considerations of the peroneal tubercle.

Gross discrepancy and error regarding the identification and location of the peroneal tubercle have been found in the literature. Furthermore, the authors found no evidence of a repeatable measurement technique in applicable descriptions of this osteologic landmark. In accordance with interrater reliability procedures, the authors established repeatability of peroneal tubercle measurements. In conjunction with the instrumentation's accuracy and resolution, the investigators infer reliability for these measurements. To the best of the authors' knowledge, this study is the only one in which interrater reliability was established for the morphometric assessment of the peroneal tubercle and the retrotrochlear eminence. The results also reestablish the correct anatomical presentation of the retrotrochlear eminence and the peroneal tubercle along the lateral surface of the calcaneus.

Nuclear magnetic resonance Hahn spin-echo decay (T2) in live rats with endotoxin lung injury.

To determine the possibility of using nuclear magnetic resonance imaging to study experimentally induced lung injury, we measured in the lungs of spontaneously breathing living rats the time course of both the Hahn spin-echo decay (T2) and the proton density after endotoxin injury. In order to minimize artifacts arising from motions of the nearby chest wall and heart, we used a motion-insensitive technique (the interleaved line scan). A typical Hahn T2 measurement was obtained over a region of interest from a series of images each with a different echo time, which ranged from 16 to 110 ms. Lung water content was determined by integrating the proton density over the region of interest. The Hahn T2 and proton density were measured before and at 1, 3, 6, and 9 h after intravenous injection of endotoxin. The effects of the treatment administered before and after endotoxin injection were also evaluated. Endotoxin treatment caused lengthening of both fast (T2f) and slow (T2s) Hahn T2 components but had no significant effect on the proton density, consistent with the notion that endotoxin causes lung injury without significant lung water accumulation in rats. However, the methylprednisolone treatment prevented the lengthening of T2s but did not seem to have a significant effect on T2f. Our results suggest that NMR imaging can be used to detect and monitor experimental lung injury in intact living animals, even in the absence of variations of lung water content.

Radiologic aspects of aging in the foot.

This article discusses technical and radiologic aspects that should be considered when evaluating the geriatric population. Potential errors and accidents will be reduced and the office will function more efficiently by advance preparation. The interpreter must be aware of anatomic variations that could potentially be misdiagnosed as a pathologic condition. Finally, the radiographic presentation of disease may differ from that presenting in younger age groups.

Rapid line scan technique for artifact-free images of moving objects.

Moving objects (e.g., heart, lung, chest wall, etc.) typically cause artifacts to appear in two-dimensional Fourier transform ("spin warp") images. The rapid line scan (RLS) technique is a simple inexpensive technique that can rapidly produce artifact-free images of moving objects, without requiring enormous magnetic field gradients or periodic motions. The basic concepts and potential industrial applications of the RLS technique are described.

Alveolar air-tissue interface and nuclear magnetic resonance behavior of lung.

Inflated lungs are characterized by a short nuclear magnetic resonance (NMR) free induction decay (rapid disappearance of NMR signal), likely due to internal (tissue-induced) magnetic field inhomogeneity produced by the alveolar air-tissue interface. This phenomenon can also be detected using temporally symmetric and asymmetric NMR spin-echo sequences; these sequences generate a pair of NMR images from which a difference signal (delta) is obtained (reflecting the signal from lung water experiencing the air-tissue interface effect). We measured delta in normal excised rat lungs at inflation pressures of 0-30 cmH2O for asymmetry times (a) of 1-6 ms. Delta was low in degassed lungs and increased markedly with alveolar opening when measured at a = 6 ms (delta 6 ms); delta 6 ms varied little during the rest of the inflation-deflation cycle. Delta 1 ms (a = 1 ms) did not vary significantly on inflation and deflation. Measurements of delta at a = 3 and 5 ms generally lay between those of delta 1 ms and delta 6 ms. These findings, which are consistent with theoretical predictions, suggest that measurements of delta at appropriate asymmetry times are particularly sensitive to alveolar opening and may provide a means of distinguishing alveolar recruitment from alveolar distension in the pressure-volume behavior of the lung.

A systematic approach for radiographically evaluating joint disease in the foot.

A methodic analysis of foot radiographs is valuable when evaluating for joint disease. The author presents a system that allows the interpreter to establish a list of expected differential diagnoses. This is especially useful when the arthritide does not present with its classic radiographic appearance.

An in vivo NMR imaging determination of multiexponential Hahn T2 of normal lung.

We describe the first in vivo imaging determination of normal lung tissue's multiexponential transverse magnetization decay. Normal spontaneously breathing rats were used for the measurements. To obtain motion-insensitive images, we used a modified line scan imaging technique which we call the interleaved line scan (ILS). The ILS overcomes the following difficulties associated with imaging lungs: low signal-to-noise ratio (S/N) due to lung's low proton density and short T2 decay, artifacts associated with cardiac and respiratory motion, and excessively long imaging times with conventional line scan techniques. Using the ILS, a 16-line 32-average image with an 8-s repetition time requires 4.3 min. From a series of 16 Hahn spin-echo images with echo times ranging from 16 to 90 ms, we obtained a two-component T2 decay for normal peripheral lung tissue. The measured fast and slow T2 components were 9.5 +/- 1.0 and 34 +/- 5.0 ms for the right lung and 9.0 +/- 1.5 and 32 +/- 4.5 for the left lung. The relative magnetization for the slow T2 component was 7.0 +/- 4.5% for the right lung and 10 +/- 3.0% for the left lung.

The radiographic presentation of osteomyelitis in the foot.

Numerous authors have described the radiographic findings associated with osteomyelitis. Knowledge of these findings and their presentation radiographically may make diagnosis of this pathology quite simple. The challenge comes not in diagnosing osteomyelitis based on gross radiographic evidence; by this time, the disease has significantly progressed. The challenge is to be able to recognize early, subtle changes, and, in conjunction with clinical findings, to diagnose and treat the disease before classic radiographic evidence is demonstrated.

Radiographic anatomy of the first metatarsal.

Normal radiographic anatomy of the first metatarsal bone is established through cadaver dissection, examination of bone specimens, and radiography. Extra-articular and distal articular anatomical landmarks are identified with wire markers. Dorsoplantar, lateral, lateral oblique, and medial oblique radiographs of 15 osteologic sites are presented, including the articular margins of the first metatarsal head, the borders of the three diaphyseal surfaces, the origins of the metatarsophalangeal collateral and metatarsosesamoid suspensory ligaments, and the insertions of the first cuneiform-metatarsal joint ligaments and the tibialis anterior and peroneus longus tendons. The correlation of gross anatomy and radiographs is described.

Coexistent gout and rheumatoid arthritis.

Gout and rheumatoid arthritis are relatively common entities individually; however, the coexistence of these two conditions has been reported rarely in the literature. The authors present a case that was followed for 20 years. The patient was seen by the acknowledged internist and podiatrist. Criteria for the evaluation and diagnosis of each disease entity are discussed and correlated to the case reported. Various theories and research attempting to explain the negative coexistence of gout and rheumatoid arthritis are presented.

Chemistry of mutagenic by-products of water chlorination.

The strong Ames mutagen 3-chloro-4-(dichloromethyl)-5-hydroxy-2 (5H)-furanone (MX) and its geometric isomer E-2-chloro-3-(dichloromethyl)-4-oxobutenoic acid (E-MX) have been shown to be present in chlorinated drinking waters. MX accounts for approximately 30% and E-MX for a few percent of the overall mutagenicity. MX and E-MX are unstable in water and undergo both pH dependent isomerization (MX in equilibrium E-MX) and hydrolytic degradation. Alternative methods of disinfection have been found to produce mutagenicity, and MX and E-MX but to a lesser extent than disinfection with chlorine. The MX analogues 3-chloro-4-(dichloromethyl)-2 (5H)-furanone (red-MX) and 2-chloro-3-(dichloromethyl)-2-butenedioic acid (ox-MX) have also been identified in chlorinated water. However, the relatively low mutagenicity of these compounds suggests that their contribution to the overall mutagenicity of chlorinated water is of only moderate significance.

Gas chromatographic/mass spectrometric identification of chlorinated and oxygenated cyclohexene artifacts formed during the analysis of chlorinated water samples.

Chlorinated and oxygenated cyclohexene derivatives detected in methylene chloride extracts of chlorinated drinking water were demonstrated to be artifacts produced during sample preparation. Commercial methylene chloride contains cyclohexene as a preservative, and this reacted during the extraction/concentration process to produce microgram amounts of chlorocyclohexene, 2-chlorocyclohexanol, trans-1,2-dichlorocyclohexane, cyclohexenone and cyclohexenol. Quantitative analysis indicated that over 90% of the initial cyclohexene was consumed during the process. Dechlorination of drinking water with sodium arsenite significantly reduced but did not eliminate cyclohexene artifact formation.