The influence of medium composition on the maintenance of cytochrome P-450, glutathione content and urea synthesis: a comparison of rat and sheep primary hepatocyte cultures

Rat and sheep primary hepatocytes have been cultured in four different medium formulations: Williams' E, Chee's, Medium 199 and Modified Earle's. The total cytochrome P450 content, intracellular concentration of reduced glutathione, rate of urea synthesis and total protein content of cultures of cells from both species in each medium have been determined. Modified Earle's and Chee's medium proved to be the most favourable formulations for the culture of rat hepatocytes. After 48 h, cells cultured in Modified Earle's had significantly more cytochrome P450 and a significantly greater rate of urea synthesis than cells in any other medium. After 6 days in culture the difference in cytochrome P450 levels between rat hepatocytes in Chee's medium and those in Modified Earle's medium was abrogated. The difference in the rate of urea synthesis between rat hepatocytes cultured in each of these two media was shown to be more dependent on the medium in which the cells were maintained during the period of urea synthesis measurement than on the medium in which the cells had been previously cultured. Sheep hepatocytes cultured in Chee's medium ruptured and died within 24 h. Apart from this, sheep cells were less sensitive to changes in medium formulation than were rat hepatocytes. The initial plating efficiency was lower in sheep cells. Total cytochrome P450 content was the most discriminatory of the four parameters for evaluating the status of rat hepatocyte cultures. However, urea synthesis may be the most useful parameter for assessment of hepatocyte function in hybrid liver devices such as bioartificial liver support systems where access to the cells during operation of the device is restricted.

Effects of ex vivo manipulation on the expression of cell adhesion molecules on neutrophils

In vitro studies of neutrophil adhesion generally utilise purified populations and are often performed at 37 degrees C. This study determines the effects of temperature changes and neutrophil separation procedures on the expression of cell adhesion molecules on neutrophils. We found that neutrophil separation procedures involving erythrocyte sedimentation and hypotonic lysis are associated with a significant increase in the expression of both a structural and functional epitope of the beta 2 integrin CD11b, an increase in the expression of sialyl Lewisx (CD15s) and the hyaluronate receptor (CD44) as well as a significant decrease in L-selectin (CD62L) expression. Separated neutrophils are also more resistant than unseparated neutrophils to PMA induced upregulation of a functional epitope of CD11b. Incubating neutrophils at 37 degrees C is associated with increases in the expression of structural and functional epitopes of CD11b. Neutrophil separation is also associated with increases in the expression of both structural and functional epitopes of CD11b which is greater when neutrophil separation is performed at room temperature compared with neutrophil separation at 0-4 degrees C. However, this difference is lost when the latter are incubated at 37 degrees C. Furthermore, neutrophil separation at both 0-4 degrees C and room temperature is associated with a significant increase in CD15s expression. This increase is less when separation is performed at room temperature. These findings suggest that neutrophil separation should be performed at room temperature unless the cells are going to be used at 0-4 degrees C. Researchers using purified neutrophil populations need to be aware of these significant structural and functional changes when extrapolating in vitro results to in vivo situations.

Postantibiotic effects and Burkholderia (Pseudomonas) pseudomallei: evaluation of current treatment

The postantibiotic effects (PAEs) OF 16 antibiotics or antibiotic combinations currently used against Burkholderia (Pseudomonas) pseudomallei were determined. The beta-lactams had zero PAEs, while the carbapenems and ciprofloxacin induced median PAEs of 1 and 5 h, respectively. These results emphasize the need to maintain antibiotic levels above inhibitory concentrations in blood throughout the dosing interval in cases of severe melioidosis.

In vitro antimicrobial susceptibilities of strains of Yersinia pestis

The in vitro activities of 14 antimicrobial agents were determined for 78 strains of Yersinia pestis. The most active antibiotics were ceftriaxone and ciprofloxacin, followed by ofloxacin and ampicillin. The agents traditionally used for the treatment of plague (streptomycin, tetracycline, and chloramphenicol) were considerably less active. Azithromycin showed poor activity against all strains.

Quantitative recovery of Burkholderia pseudomallei from soil in Thailand

Melioidosis is common in north-eastern Thailand, but is reported rarely from the adjacent areas of central Thailand, although rice farming is common to both regions. Quantitative soil cultures for Burkholderia pseudomallei were therefore prepared on 12 rice farms in both regions. B. pseudomallei was isolated from a similar proportion of rice fields in the central region (6/12) and in the north-east (7/12). Within the culture-positive sites, the number of B. pseudomallei colony-forming units (cfu) per mL of soil/water supernatant was significantly higher in the north-east (median 230 cfu/mL; range 1-17,000) than in the central region (median 10 cfu/mL; range 1-600). As bacterial counts in the soil are probably related to the risk of developing melioidosis, differences in exposure to B. pseudomallei probably contribute to the considerable differences in the incidence of this disease between these 2 adjacent regions.

Three-dimensional echocardiography: limitations of apical biplane imaging for measurement of left ventricular volume

A new three-dimensional echocardiographic system creates a "line of intersection" display to allow precise and known positioning of echocardiographic images. Our purpose was to determine whether use of the line-of-intersection display will improve positioning of the apical four-chamber and apical two-chamber views and thereby improve the agreement between estimates of left ventricular volume by apical biplane echocardiography and cineventriculography. Unguided and line of intersection-guided apical biplane views were obtained in 31 patients immediately before cardiac catheterization and single-plane cineventriculography. In 15 patients the line-of-intersection display was used to measure the position of the image plane in studies of unguided and guided methods. Linear regression and limits of agreement analysis were used to assess the agreement between cineventriculographic volumes and echocardiographic volumes determined from each set of images. The Wilcoxon test was used to compare guided and unguided image positioning. The line-of-intersection display improved four-chamber and two-chamber view positioning closer to the center of the ventricle and rotation closer to orthogonal positioning. Guided-image positioning was not able to correct displacement of the ultrasound beam anterior to the ventricular apex without deterioration of image quality in most patients. Despite improvements in image plane positioning, the agreement between echocardiographic and cineventriculographic volumes was unchanged. For end-diastole views, the unguided images had an r value = 0.84, standard error of the estimate of +/- 23.0 cc, and limits of agreement of +/- 62.4 cc. Corresponding values for the guided images at end diastole were r = 0.85, standard error of the estimate of +/- 22.9 cc, and limits of agreement of +/- 60.8 cc. At end systole the unguided results were r = 0.91, standard error of the estimate of 16.8 cc, and limits of agreement of +/- 52.2 cc. The line-of-intersection guiding of image plane positioning can improve apical image positioning but does not improve the agreement between apical biplane echocardiographic and cineventriculographic left ventricular volumes. The optimal apical imaging window is frequently occluded by the rib cage, resulting in a decrease in image quality. This reduction of image quality, combined with assumptions of left ventricular geometry, limit the accuracy of estimates of left ventricular volume from apical biplane echocardiography.

Detection of C-polysaccharide in serum of patients with Streptococcus pneumoniae bacteraemia

AIM

To investigate the fate of Streptococcus pneumoniae C-polysaccharide antigen in serum in patients with S pneumoniae bacteraemia.

METHOD

In vitro dissociation experiments were performed to demonstrate that C-polysaccharide was masked by ligands in normal and acute phase serum. Serum samples from 22 patients with S pneumoniae bacteraemia were treated to dissociate immune complexes and then tested for C-polysaccharide by enzyme linked immunosorbent assay (ELISA).

RESULTS

C-polysaccharide antigen was masked in normal and acute phase serum but could be released by EDTA treatment and detected by ELISA. Antigen was found in six patients ranging in concentration from 2.5 to 200 ng/ml. Patients with detectable antigen were more likely to die than those in whom antigen was not detected.

CONCLUSION

This study demonstrates that C-polysaccharide antigen commonly circulates in patients with S pneumoniae bacteraemia but its presence is masked by ligands present in serum.

A prospective comparison of co-amoxiclav and the combination of chloramphenicol, doxycycline, and co-trimoxazole for the oral maintenance treatment of melioidosis

An open randomized comparison of the oral 'conventional' regimen (combination of chloramphenicol, cotrimoxazole and doxycycline) and co-amoxiclav for the maintenance treatment of melioidosis was conducted in Ubon Ratchatani, north-eastern Thailand, between 1989 and 1992. The total antibiotic treatment duration was 20 weeks. Of 101 patients followed, 10 (10%; 95% confidence interval [CI] 4.9-17.5%) subsequently relapsed: 2 of 52 patients (4%) in the oral 'conventional' group, and 8 of 49 patients (16%) receiving oral co-amoxiclav. This compares with a relapse rate of 23% in our previous study of 8 weeks' total therapy. Only 50% of patients complied with the 20 weeks' treatment regimen and poor compliance proved the most significant risk factor for subsequent relapse (relative risk [RR] 4.9, 95% CI 1.2-20.3). Neither the presence of known underlying disease nor choice of initial parenteral treatment was significantly associated with a higher risk of relapse. Co-amoxiclav is safer and better tolerated, but may be less effective (RR of relapse 0.4, 95% CI 0.2-1.2) than the oral 'conventional' regimen. The minimum duration of total treatment with either regimen should be 12-20 weeks, depending on clinical progress.

Administrative databases' complication coding in anterior spinal fusion procedures. What does it mean?

STUDY DESIGN

A review of a cohort of 310 consecutive patients who underwent anterior spinal fusion was performed to evaluate the accuracy of hospital ICD-9-CM complication coding.

OBJECTIVES

To better understand the clinical significance of conclusions suggested by studies that rely on electronic administrative databases for their data source.

SUMMARY OF BACKGROUND DATA

Despite their availability, there have been no studies to date that have evaluated the accuracy of ICD-9-CM administrative databases as they relate to the actual clinical experience in spinal procedures.

METHODS

A physician and a research technician independently reviewed the primary medical records for the occurrence of complications. This data was compared with the hospital-acquired ICD-9-CM coded complications.

RESULTS

The physician reviewer identified 152 complications in 119 patients, with 32 different types of complications. The research abstracter identified 175 complications in 130 patients, with 34 different types of complications identified. Hospital ICD-9-CM coding identified 105 complications in 80 patients, including only 11 different ICD-9-CM codes. Overall, 27% of ICD-9-CM complication codes were listed as "unspecified or unclassified complications, reactions, or misadventures," and contained no meaningful clinical information. Cardiac and pulmonary complications were over-estimated and wound infections and genitourinary and gastrointestinal complications were underestimated by ICD-9-CM coding.

CONCLUSIONS

Studies of complications of spinal procedures using data derived from hospital ICD-9-CM complication codes may be intrinsically flawed because the data available to researchers from these electronic databases may be inaccurate.

Post-concussion syndrome and the coping hypothesis

Neuropsychological functioning and level of subjective symptomatology was assessed in 15 adults at 2 weeks, 1 month, and 3 months post-concussion. Performance by the concussion subjects was compared to the results obtained by a matched group of normal controls. At 2 weeks post-injury the concussion subjects had deficits in intellectual, attentional, memory, and language abilities. Visuospatial constructional abilities were relatively preserved. Concussed subjects also reported high levels of disturbance in affective, cognitive, and social functioning. By 3 months post-injury the concussed subjects were still displaying deficits in attentional and language functioning. The level of subjective symptoms reported by the concussed subjects was not significantly different from that reported by controls. Results provide some support for the 'coping hypothesis' explanation of post-concussion syndrome.

Pharmacist counseling and outcomes of smoking cessation

The Pharmacists Educating Patients Program (PEPP) was designed (1) to provide pharmacists with smoking cessation consultation guidelines for patients on nicotine transdermal therapy and (2) to test the effectiveness of these pharmacists' consultation services. More than 6,500 pharmacies and 40,220 patients participated in this program. One year after treatment began, a survey of 2,001 patients on nicotine transdermal therapy found that those who had not joined a comprehensive smoking cessation program (86.5%) but were counseled by a pharmacist had a self-reported smoking cessation rate of 37% at the end of treatment, and 33% at an average of 10 months after treatment. The average length of treatment was five weeks. Patients who participated in a comprehensive behavioral smoking cessation program, such as SmokEnders, and who also received counseling from their pharmacists (13.5% of surveyed patients) had a quit rate of 62% at the end of treatment and 45% after 10 months. Among surveyed patients, those who stopped smoking reported that their pharmacists' counseling had been more intense and more helpful than the counseling reported by those who did not stop smoking. In addition, those who stopped smoking had more pharmacist counseling interventions and more weeks on nicotine patch treatment than did those who failed to stop smoking. Results of this study show that pharmacists who counsel patients on nicotine transdermal therapy about smoking cessation can improve outcomes.

Improved hepatocyte in vitro maintenance in a culture model with woven multicompartment capillary systems: electron microscopy studies

Primary pig hepatocytes form a tissuelike structure in an in vitro culture model that has provision for three-dimensional cell orientation, cell aggregation, decentralized cell perfusion with low metabolite gradients, integral oxygenation, and nonparenchymal cell coculture. Scanning electron microscopy (SEM) has shown that hepatocytes spontaneously form aggregates in a three-dimensional structure between and on the surface of artificial capillaries. Transmission electron microscopy (TEM) has shown that after 7 weeks of in vitro perfusion, the cell ultrastructure remains similar to that of the parenchyma in vivo. Golgi complexes, active membrane processes, reorganization of cell junctions, and bile canaliculi-like intercellular spaces were demonstrated.

Up-regulation of p21WAF1/CIP1 in psoriasis and after the application of irritants and tape stripping

p21WAF1/CIP1 is a nucleoprotein that was initially characterized by its ability to be regulated transcriptionally by p53 and by its ability to mediate growth arrest by binding to cyclin-dependent kinases. Although p21WAF1/CIP1 is thought to mediate the effects of p53 in causing growth arrest, p21WAF1/CIP1 is also regulated in a p53-independent manner, e.g., during terminal differentiation of some cell lines. Growth factors including epidermal growth factor also induce p21WAF1/CIP1 through p53-independent pathways. Because the epidermal growth factor signaling pathway is abnormal in psoriatic epidermis, we studied p21WAF1/CIP1 expression, using in situ hybridization and immunohistochemistry, in psoriasis. Both p21WAF1/CIP1 mRNA and protein were significantly elevated in untreated psoriatic plaques compared with uninvolved psoriatic skin (p < 0.0001), with the up-regulation of p21WAF1/CIP1 being predominantly suprabasal. This increase was accompanied by a small increase in p53 protein expression of uncertain significance. Furthermore, p21WAF1/CIP1 expression was induced in skin after sellotape stripping and by the application of agents, such as dithranol, that are capable of inducing hyperproliferation. The pattern of p21WAF1/CIP1 expression observed is consistent with a role in induction and maintenance of differentiation. Our experiments, however, cannot determine whether the abnormalities of p21WAF1/CIP1 epidermal expression in psoriasis and after insult are independent of changes in p53 expression.

Echo Doppler evaluation of patients with acute mitral regurgitation: superiority of transesophageal echocardiography with color flow imaging

Acute mitral regurgitation is a medical emergency that requires prompt, accurate diagnosis and urgent therapy. Although the use of echo Doppler imaging has been described in these patients, preliminary observations have suggested that color flow Doppler performed from the standard transthoracic windows may underestimate the severity of mitral insufficiency in this setting. The aim of this study was to compare transesophageal color Doppler quantitation of regurgitation with results obtained from standard transthoracic windows in patients with acute, severe mitral regurgitation. Two-dimensional echocardiography with pulsed, continuous, and color flow Doppler was performed by both transthoracic and transesophageal methods in 16 consecutive patients who were documented to have acute severe mitral insufficiency by catheterization. Transthoracic and transesophageal scans were reviewed by two blinded observers and assessed for the detection of mitral regurgitation by transthoracic pulsed wave (81%), continuous wave (100%), and color flow Doppler (81%) compared with transesophageal color flow imaging (100%; p = NS). Severity of mitral regurgitation was graded as none, mild, moderate, or severe on the basis of existing transthoracic pulsed wave and color flow criteria and compared with transesophageal color flow grading. At first examination patients were critically ill, with elevated pulmonary wedge pressures (mean 27 +/- 7 mm Hg) and V waves (mean 45 +/- 10 mm Hg). Fifteen of the patients underwent emergency surgery, and the overall hospital mortality rate was 12%. Maximal color flow jet areas were significantly greater on transesophageal scanning (mean 10.5 cm2) compared with transthoracic color jets (mean 2.3 cm2).(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiography in the evaluation of thoracic trauma

Echocardiography has become a useful diagnostic modality in the evaluation of cardiovascular injury after thoracic trauma. Valuable information about cardiac wall motion, valvular function, pericardial effusions, and ventricular volume status can be obtained without significant risk. More recent application for the diagnosis of traumatic aortic disruption provides a safer, easier, less expensive, and more accurate method for detecting these injuries. Cardiac evaluation with TTE is unsuccessful in approximately 20% of examinations and is unable to provide the image resolution of the more invasive transesophageal approach.

Treatment of ocular fungal infections with oral fluconazole

PURPOSE

We treated five patients who had ocular fungal infections with oral fluconazole to determine its safety and effectiveness.

METHODS

We reviewed the case histories of the five patients. One patient had coccidioidomycosis and four had endogenous Candida endophthalmitis.

RESULTS

The intraocular fungal infection resolved in all patients.

CONCLUSION

Fluconazole appears to be a safe and effective antifungal agent that can be administered orally and may be a useful agent for treating some intraocular fungal infections.

Comparison of the suppressive effects of interleukin-10 and interleukin-4 on synovial fluid macrophages and blood monocytes from patients with inflammatory arthritis

This study determined the potential capacity of interleukin-10 (IL-10), compared with IL-4, to control the production of tumour necrosis factor-alpha (TNF-alpha), IL-1 beta and IL-1 receptor antagonist (IL-1ra) and the expression of major histocompatibility complex (MHC) class II antigens by monocytes/macrophages isolated from synovial fluid of patients with rheumatoid or other forms of chronic inflammatory arthritis. Mononuclear cells were isolated from synovial fluid and peripheral blood and incubated with or without lipopolysaccharide (LPS), and with or without IL-10 (100 U/ml, 10 ng/ml) or IL-4 (10 ng/ml) for 22 hr. TNF-alpha, IL-1 beta and IL-1ra levels were measured by enzyme-linked immunosorbent assay (ELISA) in the culture supernatants, and MHC class II expression was examined on the monocytes/macrophages by flow cytometry. IL-10, unlike IL-4, decreased TNF-alpha production by LPS-stimulated synovial fluid cells to the same extent as by LPS-stimulated peripheral blood cells from the same patients. IL-10 and IL-4 suppressed equally IL-1 beta production by the same cells. However, only IL-4 significantly increased IL-1ra production by synovial fluid mononuclear cells. Synovial fluid cells expressed increased levels of MHC class II antigen, and these levels were not as efficiently suppressed by IL-10 as they were for peripheral blood cells. Because IL-10 and IL-4 differentially regulate TNF-alpha and IL-1ra production by synovial fluid mononuclear cells, selective use of either IL-10 or IL-4 in the treatment of chronic inflammatory conditions will depend on whether TNF-alpha or IL-1, respectively, is established as primarily responsible for the maintenance of the chronic inflammatory condition.

Cervical radiculopathy: causes and surgical treatment

This article discusses the basic pathological, anatomical, and clinical problems associated with the herniated cervical disc or degenerative cervical disc disease and provides an overview of the common surgical approaches to the operative treatment of this common degenerative disorder.