Can leucocyte esterase replace frozen sections in the intraoperative diagnosis of prosthetic hip infection?

AIMS

Leucocyte esterase (LE) has been shown to be an accurate marker of prosthetic joint infection (PJI), and has been proposed as an alternative to frozen section (FS) histology for intraoperative diagnosis. In this study, the intraoperative assessment of LE was compared with FS histology for the diagnosis of prosthetic hip infection.

PATIENTS AND METHODS

A total of 119 patients undergoing revision total hip arthroplasty (THA) between June 2015 and December 2017 were included in the study. There were 56 men and 63 women with a mean age of 66.2 years (27 to 88). Synovial fluid was collected before arthrotomy for the assessment of LE using enzymatic colourimetric strips. Between five and six samples were stained with haematoxylin and eosin for FS histology, and considered suggestive of infection when at least five polymorphonuclear leucocytes were found in five high-power fields.

RESULTS

The sensitivity and specificity of the LE assay were 100% and 93.8%, respectively; the positive (PPV) and the negative (NPV) predictive values were 79.3% and 100%, respectively. The mean time between the collection of the sample and the result being known was 20.1 minutes (sd 4.4). The sensitivity and specificity of FS histology were 78.3% and 96.9%, respectively; the PPV and the NPV were 85.7% and 94.9%, respectively. The mean time between the collection of the sample and the result being known was 27.2 minutes (sd 6.9).

CONCLUSION

The sensitivity of LE assay was higher, with similar specificity and diagnostic accuracy, compared with FS histology. The faster turnaround time, its ease of use, and low costs make LE assay a valuable alternative to FS histology. We now use it routinely for the intraoperative diagnosis of PJI. Cite this article: Bone Joint J 2019;101-B:372-377.

Plasma endocannabinoid behaviour in total knee and hip arthroplasty

Endocannabinoids are a class of lipid mediators involved in a wide range of physiological pathways including pain perception, and immunological defences. In particular, the involvement of endocannabinoids in bone metabolism and bone resorption has recently been studied. Moreover, one study on total knee arthroplasty describes the probable role of endocannabinoids in pain perception after surgery. The aim of the present study was to evaluate variations of endocannabinoid concentrations in patients undergoing total hip or total knee arthroplasty before and after surgery. Sera from 23 patients were collected at three different times: before surgery and at two different times during rehabilitation, and endocannabinoids were quantified by HPLC-MS/MS analysis. Mean values of endocannabinoids in presurgical serum samples were: 6.11±0.5 ng/ml for N-palmitoylethanolamide, 1.39±0.08ng/ml for N-stearoylethanolamide, 4.84±0.04 ng/ml for N-oleoylethanolamide, 0.44±0.03ng/ml for N-arachidonoylethanolamide, 0.84±0.05ng/ml for N-linoleoylethanolamide, 0.17±0.01ng/ml for N-α-linolenoylethanolamide. Statistical analysis showed a significant decrease of all the endocannabinoids after surgery, while there were no remarkable differences between total hip and total knee arthroplasties or between genders. Moreover, the results show no significant correlation between endocannabinoid concentrations and C-reactive protein and Erythrocyte sedimentation rate. The present study shows for the first time a specific and univocal behaviour of six endocannabinoids and N-acylethanolamides in orthopaedic surgery, suggesting the endocannabinoid system as a possible pharmacological target for presurgical therapeutics.

Prolonging culture to 15 days improves bacterial detection in bone and joint infections

Since the optimal incubation period of cultures for diagnosis of bone and joint infections is still a matter of debate, the present study aimed to evaluate the effects of different incubation periods (5 and 15 days) on microbial isolation. Samples from 387 patients with bone and joint infections (including prosthetic ones) were analyzed from March 2012 to February 2014. In 197 patients (51 %) growth was obtained within 48 hrs, while in 124 (32 %) and 66 (17 %) patients cultures yielded positive results within and after 5 days of incubation, respectively. Of 449 microorganisms isolated, 247 grew within 48 hrs, 131 within the first 5 days of incubation while 71 were isolated after 5 days. Staphylococcus aureus was the most frequently isolated pathogen within 48 hrs, while Propionibacteria were prevalently isolated after 5 days of incubation. Interestingly, about 25 % of microorganisms isolated after 5 days of incubation were coagulase-negative staphylococci. Extending incubation period of broth cultures improves isolation rates of pathogens involved in bone and joint infections thus improving management of these infections.

Age-dependence of risk factors for carotid stenosis: an observational study among candidates for coronary arteriography

In order to identify subjects at higher risk for carotid stenosis and to provide insights into mechanisms of disease development at different age-intervals, a color duplex ultrasound of extracranial arteries was performed in 624 consecutive patients (mean age 62.9+/-10.7, 483 males) undergoing coronary angiography. Significant carotid atherosclerosis (> or =50% stenosis) was documented in 87 patients (14%): the disease was moderate (50/69% stenosis) in 51 patients (8%), severe (> or =70% stenosis) in 36 patients (6%). Age (P<0.0001), smoking (P<0.0001), diabetes (P=0.0002), renal dysfunction (P=0.0119) and hypertension (P=0.0202) were independent predictors of significant carotid atherosclerosis; age (P=0.0001), smoking (P=0.0009) and diabetes (P=0.0201) were independent predictors of severe disease. Among 262 candidates for cardiac surgery, significant carotid artery disease was identified in 57 cases (2.63 Relative Risk, 95% Confidence Intervals: 1.32/5.24). Correlation and regression tree analysis demonstrated that diabetes was associated with greater severity of carotid stenosis in younger patients and hypertension in older ones. In conclusion age is the primary determinant of carotid artery disease; diabetes and smoking accelerate progression of atherosclerosis in younger patients, hypertension and smoking in older ones. Among patients undergoing coronary angiography, carotid ultrasonography should be recommended in high risk subgroups of patients.

Color duplex scanning for the identification of extracranial atherosclerosis in patients with suspected coronary artery disease

BACKGROUND

The presence of extracranial artery disease has been used as a predictor of coronary artery disease (CAD). The present study was conducted to test the prevalence of extracranial artery disease among patients with suspected CAD.

METHODS

Among candidates for coronary arteriography, 400 consecutive patients (mean age 63 +/- 11 years, 78% males, 22% females) underwent color duplex ultrasound of carotid arteries.

RESULTS

Extracranial artery disease was documented in 60 patients (15%), CAD in 309 patients (77%). Patients with extracranial artery disease were significantly older (p < 0.001), smoked a higher amount of pack-years (p < 0.001), showed a higher incidence of diabetes (p < 0.01), hypertension (p < 0.05) and CAD (p < 0.05) when compared to extracranial artery disease-free subjects. Plotting age against extracranial artery disease and CAD distribution, extracranial artery disease occurred later in life than CAD (p < 0.001). The best cut-off point of age for predicting extracranial artery disease was 68 years. Carotid angiography was performed in 114 patients after cardiac catheterization (k = 0.8044 with color duplex scanning).

CONCLUSIONS

Extracranial artery disease is frequent among patients undergoing coronary arteriography. Carotid ultrasound screening is useful in older patients.

[Carotid atherosclerosis in patients with suspected coronaropathy: the relationship to traditional risk factors in the 2 vascular areas]

In order to evaluate the prevalence of carotid atherosclerosis (CA) in patients with coronary artery disease (CAD) and to identify the differential role of traditional risk factors, we analyzed data concerning 290 patients aged 61.9 +/- 10.8 years who underwent color duplex ultrasound of extracranial arteries before coronary angiography. Significant CA (stenosis > or = 50% in at least one extracranial artery) was disclosed in 44 patients (15%); significant CAD (stenosis > or = 70% at least in a major epicardial vessel) was documented in 238 patients (82%). Age and smoking were significantly associated with both CAD (respectively, p = 0.034 and p = 0.050) and CA (respectively, p = 0.000 and p = 0.000), but a stronger correlation was documented with CA (r = 0.325 vs r = 0.125 for age; r = 0.218 vs r = 0.114 for smoking). Diabetes (p = 0.031) and male gender (p = 0.016) were significantly associated with CAD, and hypertension (p = 0.029) with CA.

CONCLUSIONS

Traditional risk factors play different roles in the pathogenesis of atherosclerotic disease of carotid and coronary circulation. Color duplex evaluation of the carotid arteries can be useful in high-risk patients, particularly if candidates for coronary surgery.

[Single coronary artery with a right origin: angiography identification of the R-II subgroup]

This case report illustrates the clinical and angiographic findings of 2 patients undergoing coronary angiography for ischemic heart disease and with the unexpected presence of anomalous origin of the left coronary artery from the right aortic sinus. The angiographic classification of the different subgroups of single coronary artery is reviewed and the 2 cases are identified as type R-II with septal and anterior course of the left main stem.

Percutaneous coronary angioplasty of radial artery conduits

The higher long-term patency of internal mammary artery grafts has stimulated the search for alternative conduits in order to achieve a complete arterial myocardial revascularization. Percutaneous angioplasty is often the preferred strategy for the treatment of recurrent ischemia in patients who previously underwent bypass surgery, but there is limited experience in the treatment of arterial grafts. We describe two cases of percutaneous treatment of diseased radial artery (RA) grafts. In the first case, two disarticulated stents were deployed through an RA graft: half stent inside the anastomosis to the left anterior descending (LAD) artery, and half stent in the distal LAD artery. Diffuse spasm of the RA graft, resistant to ic nitrates, was successfully reversed after ic calcium antagonists. Absence of restenosis was confirmed two years later. In the second case, after simultaneous catheterization of both the left coronary artery and RA graft, two long stents were implanted in the LAD artery and a final "reversed" kissing-balloon dilation through the stent struts was performed; four months later the patient showed proximal occlusion of the LAD artery and the stenotic RA distal anastomosis was successfully dilated.

An uncommon false aneurysm of the left ventricle

An 83-year-old woman with previous closed transventricular commissurotomy was admitted for congestive heart failure. Echocardiogram and angiography demonstrated a mitral restenosis and a large-mouthed false aneurysm of the left ventricle.

Illness behaviour and anxiety in dental patients

The Authors evaluate the influence of illness behaviour (measured by IBQ) on patients' delay in seeking dental treatment for caries or periodontal pathology, and the relationship with anxiety (measured by STAI) and with social--demographic and clinical data. One hundred patients were studied. Delay in coming for a dental visit is influenced by family habit, level of education and fear experienced. The 'late' patients present significantly higher scores for denial on the IBQ. More serious pathology is in relation with greater denial. Anxiety is positively correlated with the IBQ scales dysphoria, hypochondria, disease conviction, irritability and inversely with denial.

Effect of ischaemia-reperfusion on glutathione peroxidase, glutathione reductase and glutathione transferase activities in human heart protected by hypothermic cardioplegia

The activities of glutathione peroxidase (GSH-px), glutathione reductase (GSSG-rx) and glutathione transferase (GST) were measured in myocardial specimens obtained from right atria of patients subjected to different period of ischaemic arrest (aortic clamping ranging from 10 min to 90 min) followed by 60 min. of reperfusion, during open heart surgery 41-90 min. period of aortic clamping induced a significant increase of GSH-px activity with both H2O2 (p less than 0.05) and cumene hydroperoxide (p less than 0.025) as substrates when compared with baseline levels. Aortic clamping and reperfusion, however did not significantly change the myocardial activities of glutathione transferase and glutathione reductase. It is suggested that the increase of GSH-px in ischaemic-reperfused human hearts may render the myocardium less susceptible to oxidative attack particularly during the reoxygenation period when the level of active oxygen species is greatly elevated.

[Blood platelet count and bubble oxygenators. Changes induced by the oral administration of dipyridamole]

The changes in thrombocythemia in patients subjected to extracorporeal circulation (ECC) and pretreated with dipyridamole per os have been examined and compared with a control group in whom the drug was not used; in all patients a circuit with bubble oxygenator was employed. Measurements were carried out before sternotomy, 10' and 60' after ECG, 1 h after the start of intensive therapy and on the 1st surgical day. The variations in thrombocythemia were assessed in consideration of the thrombocythemia/Ht ratio, so as to eliminate the dilution variable. On the basis of the results obtained, it is considered that preoperative treatment with dipyridamole is effective in limiting the fall in thrombocythemia during ECC. The effect of the drug is prevalent in the initial stage of ECC, probably reducing platelet aggregation to non-biological surfaces of the circuit.

New fluorinated erythromycins obtained by mutasynthesis

Following the previously described semisynthetic preparation of new aglycones (8S)-8-fluoroerythronolide A (I), (8S)-8-fluoroerythronolide B (II) and the monoglycoside 3-O-mycarosyl-(8S)-8-fluoroerythronolide B (III), their conversion into new fluoroerythromycins was attempted by mutational biosynthesis. The strain Streptomyces erythraeus ATCC 31772, a mutant blocked in the biosynthesis of erythromycin, was employed in the present investigation. Four new antibiotics, (8S)-8-fluoroerythromycin A (IV), (8S)-8-fluoroerythromycin B (V), (8S)-8-fluoroerythromycin C (VI) and (8S)-8-fluoroerythromycin D (VII) were successfully derived by such an approach. The result is also discussed in terms of the substrate specificity of the enzymes involved in the biosynthesis of erythromycins. The new antibiotics exhibited promising biological properties.

Biological conversion of erythronolide B, an intermediate of erythromycin biogenesis, into new "hybrid" macrolide antibiotics

Transformation of erythronolide B to new antibiotics was attempted by feeding this compound during the fermentation of Streptomyces antibioticus ATCC31771, a blocked mutant of an oleandomycin producing strain. As a result, four new active compounds were obtained with hybrid structures between erythromycin and oleandomycin. They were identified as 3-O-oleandrosyl-5-O-desosaminyl-15-hydroxyerythronolide B (I), 3-O-oleandrosyl-5-O-desosaminylerythronolide B (II), 3-O-oleandrosyl-5-O-desosaminyl-(8S)-8-hydroxyerythronolide B (III) and 3-O-oleandrosyl-5-O-desosaminyl-(8R)-8,19-epoxyerythronolide B (IV). They were found to be less active, but more stable to acid, than erythromycin A. From their relative biogenetical relationship together with the structure elucidated some hypotheses about late stages of oleandomycin biosynthesis are inferred too.