Evaluation of risk factors for surgical site infections in osteoarthritis patients undergoing total knee arthroplasty.

This research sought to delineate risk factors associated with surgical site infections (SSIs) post-total knee arthroplasty (post-TKA) in elderly osteoarthritis patients, aiming to enhance post-surgical outcomes. A retrospective examination was conducted on a cohort of 650 elderly patients who underwent unilateral TKA between January 2018 and August 2022. Data procurement was from the hospital's Electronic Health Record, and a comprehensive statistical evaluation was performed using IBM SPSS Statistics version 24.0. Both univariate and multivariate techniques assessed a spectrum of risk determinants such as age, body mass index (BMI), coexisting medical conditions and surgical variables. The univariate examination spotlighted age, BMI, diabetes prevalence, chronic corticosteroid consumption and American Society of Anesthesiologists (ASA) physical status classification as notable predictors of SSIs. The multivariate logistic regression pinpointed age, BMI, history of smoking and diabetes diagnosis as salient risk attributors for post-TKA infections. Concurrently, parameters like ASA classification, surgical duration and intraoperative haemorrhage further enriched the risk landscape. Geriatric patients undergoing TKA for knee osteoarthritis manifest a tangible infection susceptibility post-surgery. Precision interventions concentrating on amendable risk components, including meticulous preoperative evaluations and strategic postoperative care, are imperative to attenuate SSI incidence, thereby amplifying surgical efficacy and optimizing patient recuperation trajectories.

Drug resistance characteristics and spatial clustering of Mycobacterium tuberculosis in Qinghai Province from 2016 to 2019 / 中国热带医学

@#Abstract: Objective To analyze the resistance and spatial distribution of Mycobacterium tuberculosis (MTB) to six commonly used anti-tuberculosis drugs in Qinghai Province from 2016 to 2019, so as to provide a reference for tuberculosis treatment and drug-resistant tuberculosis control. Methods A total of 1 182 identified strains of Mycobacterium tuberculosis in Qinghai Province from 2016 to 2019 were collected, and 6 anti-tuberculosis drugs were subjected to drug susceptibility tests and strain confirmed by the proportional method. By means of ArcMap10.7 and SaTScan10.1 software, map visualization, spatial autocorrelation analysis and spatial scanning of MTB drug resistance were performed to identify MTB drug resistance clusters in Qinghai Province. Results From 2016 to 2019, the total drug resistance (TDR) rate of 1 182 Mycobacterium tuberculosis strains in Qinghai Province was 23.77% (281/1 182), with a mono-resistance (MR) rate of 11.08% (131/1 182), a poly-resistance (PDR) rate of 3.89% (46/1 182), a multi-drug resistance (MDR) rate of 8.80% (104/1 182), and an extensive drug resistance (XDR) rate of 0.85% (10/1 182). The rates of MDR, XDR and TDR all showed a decreasing trend year by year (P<0.01). The drug resistance spectrum displayed 21 combinations. The TDR rate and MDR rate in the retreatment patients were higher than those of the initial treated patients, and the difference was statistically significant (χ2 TDR=22.784, χ2MDR=45.082, P<0.01). In terms of demographic characteristics, the TDR rate in males was higher than that in females, and the middle-aged group was higher than other age groups, and the differences were statistically significant (χ2=7.541, 10.825, P<0.05). The results of global spatial autocorrelation analysis showed that there was no statistical significance in the autocorrelation and obvious spatial clustering of MTB drug resistance in Qinghai Province from 2016 to 2019 (P>0.05), which indicated a random distribution. The results of spatiotemporal scanning showed that there was a kind of clustering area, but the clustering effect was not significant (P>0.05), indicating a random distribution. Conclusions The TDR of MTB in Qinghai Province from 2016 to 2019 showed a downward trend year by year. In comparison with the national average, the rate of multi-drug resistance and extensive drug resistance was still high, and most of the multi-drug resistance resulted from rifampicin and isoniazid. The drugresistant population mainly consisted of retreatment, males, and young and middle-aged pop

The predictive value of coronary artery calcification score combined with bone mineral density for the 2-year risk of cardiovascular events in maintenance hemodialysis patients.

PURPOSE: Cardiovascular disease is the leading cause of death in maintenance hemodialysis (MHD) patients. The aim of this study is to investigate the predictive value of coronary artery calcification score (CACs) combined with bone mineral density (BMD) for the risk of cardiovascular diseases in MHD patients. METHODS: From January 2017 to January 2019, we enrolled 112 MHD patients and 112 controls in Ningbo First Hospital, and retrospectively counted the cardiovascular events in the next 2 years after enrollment. According to the occurrence of cardiovascular events, the MHD patients were divided into CVD group and non-CVD group. The differences of vertebral BMD and CACs between the two groups were compared. ROC curve, Kaplan-Meier curve and Cox regression analyses were used for assess the predictive value of 2-year cardiovascular events in MHD patients. RESULTS: Among 112 MHD patients, 49 (43.75%) patients had cardiovascular events. The results showed that the average value of BMD in MHD patients was significantly lower than that in the control group (99.88 ± 30.99 VS. 108.35 ± 23.98, P = 0.0231). The CACs in MHD patients were significantly higher than that in the control group (317.81 ± 211.53 VS. 190.03 ± 100.50, P < 0.001). The results between CVD group and the non-CVD group were to the same direction (BMD: 81.12 ± 31.28 VS. 114.48 ± 21.61, P < 0.001; CACs: 447.16 ± 234.11 VS. 217.21 ± 119.03, P < 0.001). Besides, CACs combined with BMD yield an AUC of 0.875 with a sensitivity of 79.60%, a specificity of 82.50%. Kaplan-Meier curve and Cox regression analyses indicated that CACs and BMD were independently associated with high risk of cardiovascular events in MHD patients. CONCLUSION: The combination of CACs and vertebral BMD could predict the occurrence of cardiovascular events in MHD patients to some extent.

Epidemiological characteristics of pulmonary tuberculosis among students in Qinghai Province from 2016 to 2019 / 中国学校卫生

Objective@#The study aims to explore the epidemiological characteristics of tuberculosis among students in Qinghai Province, to provide scientific basis for the prevention and control of students tuberculosis.@*Methods@#Data on tuberculosis among students from 2016 to 2019 in Qinghai province were collected and epidemiological characteristics were analyzed, the spatial distribution map were drawn by using ArcMap 10.8.@*Results@#During 2016-2019, there were 2 691 reported cases of tuberculosis among students in Qinghai Province the reporting rate were 46.10/10 5, 68.50/10 5, 73.49/10 5, 85.96/10 5, increased year by year( χ 2=116.45, P <0.01). With a high incidence from March to September each year. The tuberculosis patients were mainly aged 18 years and above, with more reported female cases than male cases and more Tibetan cases. Most of students tuberculosis cases were reported in southern Qinghai, especially in Yushu and Guoluo areas, and sharp increase was observed in Xining during 2018 to 2019.@*Conclusion@#Students tuberculosis in Qinghai is still serious. Schools should strengthen education on tuberculosis prevention, especially those in southern Qinghai and Xining.

Preparation and Anti-Mold Properties of Nano-ZnO/Poly(N-isopropylacrylamide) Composite Hydrogels.

The aim of this study was to overcome drawbacks of the inhomogeneous dispersion and facile agglomeration of nano-ZnO/poly(N-isopropylacrylamide) composite hydrogels (nano-ZnO/PNIPAm composite hydrogels) during synthesis and improve the anti-mold property of the nano-ZnO/PNIPAm composite hydrogels. Here, nano-ZnO/PNIPAm composite hydrogels were prepared by the radical polymerization method. Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), differential scanning calorimeter (DSC), and dynamic light scattering (DLS) were used to characterize the effects of different dispersants on the particle sizes, dispersions, and phase transition characteristics of the nano-ZnO/PNIPAm composite hydrogels. The anti-mold properties of nano-ZnO/PNIPAm composite hydrogels were studied. Results revealed that the nano-ZnO/PNIPAm composite hydrogel prepared by the addition of nano-ZnO dispersion liquid exhibited the smallest particle size, the most homogeneous dispersion, and the highest stability. The addition of the dispersant did not change the phase transition characteristics of nano-ZnO/PNIPAm, and the nano-ZnO/PNIPAm composite hydrogels (Pf) exhibited good anti-mold properties to the bamboo mold.

Traumatic vertebral fractures involve the anterior end plate more than the posterior end plate: A retrospective study.

Traumatic end plate fractures (EPFs) refers to the EPF caused by trauma, rather than the pathological status of the end plate (EP). However, some old traumatic EPFs may be mistaken as osteoporotic in the elderly. The objective of this study is to describe the radiological features of traumatic EPF in different traumatic fracture type patients presenting in the Emergency department setting. And to compare the result with osteoporotic vertebral fracture (VF).This study retrospectively analyzed the anatomical location of acute thoracolumbar vertebral traumatic EPFs in males (age≤55 years) and females (age≤50 years). The anatomic distribution of EPFs, the anterior and posterior wall fracture were analyzed in patients, who were scanned with 1 or more of the following methods: radiography, CT, and magnetic resonance imaging.There were 194 cases of acute spine trauma involving at least 1 EPF, including 118 males and 76 females. The involved vertebra was mostly at L1 (29.7%), followed by T12 (18.3%), and then by L2 (12.9%). Excluding those with both upper and lower EP involvements, the ratio of superior EPF to inferior EPF was 33.5 for males and 45.5 for females. With the EP divided into 5 segments of equal length in the anteroposterior direction in different fracture types, fractures occurred mostly at a2 segment (71.48% for superior EPs and 7.60% for inferior EPs), followed by a1 segment (66.16% for superior EPs). The upper third of the anterior and posterior walls were most prone to fracture in traumatic vertebral fracture.Traumatic EPFs more likely involve the anterior EP more than the posterior EP and is correlated with fracture type. These characteristics may help radiologist differential diagnosis between traumatic and osteoporotic EPF.

Radiological features of traumatic vertebral endplate fracture: an analysis of 194 cases with 263 vertebral fractures.

BACKGROUND: The importance of identifying osteoporotic vertebral endplate or/and cortex fracture (ECF), which primarily includes endplate fracture (EPF) and vertebral anterior cortex buckling, has been recognized. However, some old traumatic ECFs with healing process in the elderly may be mistaken as osteoporotic. This study analyzes the radiological features of traumatic EPF. METHODS: This was a retrospective analysis of 194 spine trauma patients with 263 vertebral fractures (mean age: 42.11 ±â€Š9.82 years, 118 males and 76 females). All patients had traumatic EPF identified by X-ray/CT/MRI. RESULTS: The involved vertebra was mostly L1 (29.7%), followed by T12 and L2. Except EPFs involved both superior and inferior endplates (12.6%), only 1.9% involved inferior endplate alone, with the majority involved superior endplate. If each endplate was divided into five segments of equal lengths (from anterior to posterior: a1, a2, m, p2, p1), the most depressed point of superior EPFs was mostly at segment-a2 (approximately 45%), followed by segment-a1 (approximately 20%) or segment-m (approximately 20%), and very rarely at segment-p1. The upper 1/3 of anterior vertebral wall was more likely to fracture, followed by middle 1/3 of anterior wall. For posterior vertebral wall fracture, 68.5% broke the bony wall surrounding the basivertebral vain. 58.6%, 30.0%, and 11.4% of vertebral fractures had <1/5, 1/5-1/3, and >1/3 vertebral body height loss. As the extent of vertebral height loss increased, the chance of having both superior and inferior EPFs also increased; however, the chance of having inferior EPF alone did not increase. CONCLUSION: Traumatic EPF features are characterized, which may help the differentiation of traumatic and osteoporotic EPFs.

Xanthoma Combined With Gout Infiltration of the Achilles Tendon: A Case Report.

Xanthoma is a rare condition mostly caused by hyperlipidemia. The pathogenesis of gout is hyperuricemia, which is caused by a disorder of purine metabolism and/or a decrease in uric acid excretion. Xanthoma combined with gout is very rare. This case report presents magnetic resonance images of a case of xanthoma combined with gout infiltration of the Achilles tendon.

Diagnosis of coronary artery disease in patients with atrial fibrillation using low tube voltage coronary CT angiography with isotonic low-concentration contrast agent.

This prospective study evaluated the image quality and accuracy of coronary computed tomography angiography (CCTA) for diagnosing coronary artery disease (CAD) in patients with atrial fibrillation (AF), in which CCTA used adaptive iterative dose reduction (AIDR) with a low tube voltage and low concentration of isotonic contrast agent. Sixty-eight consecutive patients with AF and suspected CAD were equally and randomly apportioned to two groups and underwent CCTA. In the experimental group, the contrast agent was iodixanol (270 mg I/mL), patients were scanned with 100 kV, and reconstruction was by AIDR. In the conventional scanning (control) group, the contrast agent was iopromide (370 mg I/mL), patients were scanned with 120 kV, and reconstruction was by filtered back projection. The image quality, effective radiation dose (E), and total iodine intake of the groups were compared. Thirty-nine patients with coronary artery stenosis later were given invasive coronary angiography (ICA). The groups were similar with regard to mean CT value, noise, and signal-to-noise and contrast-to-noise ratios. The figure of merit of the experimental group was significantly higher than that of the control group, while the E and total iodine were significantly lower. Using ICA as the diagnostic reference, the groups shared similar sensitivity, specificity, and false positive and false negative rates for diagnosing coronary artery stenosis. For determining CAD in patients with AF, CCTA with isotonic low-concentration contrast agent and low-voltage scanning is a feasible alternative that improves accuracy and reduces radiation dose and iodine intake.

Keeping eggs warm: thermal and developmental advantages for parasitic cuckoos of laying unusually thick-shelled eggs.

Obligate brood parasites have evolved unusually thick-shelled eggs, which are hypothesized to possess a variety of functions such as resistance to puncture ejection by their hosts. In this study, we tested the hypothesis that obligate brood parasites lay unusually thick-shelled eggs to retain more heat for the developing embryo and thus contribute to early hatching of parasite eggs. By doing so, we used an infrared thermal imaging system as a non-invasive method to quantify the temperature of eggshells of common cuckoos (Cuculus canorus) and their Oriental reed warbler (Acrocephalus orientalis) hosts in an experiment that artificially altered the duration of incubation. Our results showed that cuckoo eggshells had higher temperature than host eggs during incubation, but also less fluctuations in temperature during incubation disturbance. Therefore, there was a thermal and hence a developmental advantage for brood parasitic cuckoos of laying thick-shelled eggs, providing another possible explanation for the unusually thick-shelled eggs of obligate brood parasites and earlier hatching of cuckoo eggs compared to those of the host.

The feasibility of low-concentration contrast and low tube voltage in computed tomography perfusion imaging: an animal study.

Aim: To investigate the feasibility of low-concentration contrast (270 mg/ml) together with low tube voltage (80 kV) and adaptive iterative dose reduction (AIDR)-3D reconstruction in liver computed tomography (CT) perfusion imaging.Method: A total of 15 healthy New Zealand rabbits received two CT scans each. The first scan (control) was acquired at 100 kV and 100 mA with iopromide (370 mg/ml), while the second scan (experimental) was acquired at 80 kV and 100 mA with iodixanol (270 mg/ml) 24 h after the first scan. The obtained images were reconstructed with filtered back projection (FBP) and AIDR-3D in the control and experimental groups respectively. The perfusion parameters (hepatic artery perfusion [HAP], portal vein perfusion [PVP], hepatic perfusion index [HPI], and total liver perfusion [TLP]) and image quality (image quality score, average CT value of abdomen aorta, signal-to-noise ratio [SNR], contrast-to-noise ratio [CNR], and figure of merit [FOM]) were compared using a paired t-test or Mann-Whitney U test between the two groups, when appropriate. The effective radiation dose and iodine intake were also recorded and compared.Results: With the exception of the FOM criteria, the image quality and perfusion parameters were not significantly different between the two groups. The effective radiation dose and iodine intake were 38.79% and 27.03% lower respectively, in the experimental group.Conclusion: Low-concentration contrast (iodixanol, 270 mg/ml) together with low tube voltage (80 kV) and AIDR-3D reconstruction help to reduce radiation dose and iodine intake without compromising perfusion parameters and image quality in liver CT perfusion imaging.

Diagnostic value of four-dimensional CT angiography in arterial erectile dysfunction using 320-detector row dynamic volume CT.

The present study aims to evaluate the diagnostic value of four-dimensional CT angiography (4D-CTA) in the diagnosis of arterial erectile dysfunction (ED) using 320-detector row dynamic volume CT. Arterial ED patients attributed to arterial insufficiency were enrolled. To induce penile erection, an intracavernous injection (ICI) of corpus cavernosum with a vasoactive drug was administered. Patients were assigned into the erection hardness score (EHS) 1/2 group or EHS 3/4 group. Color duplex Doppler ultrasound (CDDU) was used to analyze blood flow spectrum. Each patient was examined using 4D-CTA. Receiver operating characteristic (ROC) curve was plotted to evaluate the diagnostic value of 4D-CTA in arterial ED. According to Irwin Goldstein, the EHS 3/4 group (n=38) had a shorter course of ED and low proportion with history of hypertension, hyperlipidemia, and diabetes than the EHS 1/2 group (n=35). The peak systolic velocity (PSV), end diastolic velocity (EDV), and resistant index (RI) in the EHS 3/4 group were lower than those of the EHS 1/2 group. 4D-CTA showed there were a total of 35 cases in the EHS 1/2 group (two cases missed) and 38 cases in the EHS 3/4 group (seven cases misdiagnosed). Using 4D-CTA to diagnose arterial ED, the area under the ROC curve yielded a value of 0.879, with a specificity of 93.9% and a sensitivity of 82.5%. These findings indicated that 4D-CTA using 320-detector row dynamic volume CT is a promising and reliable utility in diagnosing arterial ED.

Comprehensive assessment of cavernosography with 320-row dynamic volume CT versus conventional cavernosography in erectile dysfunction patients caused by venous leakage.

The present study aims to investigate and compare the diagnostic and prognostic value of cavernosography with 320-row dynamic volume computed tomography (DVCT) versus conventional cavernosography in men with erectile dysfunction (ED) caused by venous leakage. A total of 174 patients diagnosed with ED were enrolled and received cavernosography with 320-row DVCT (DVCT group) and conventional cavernosography scans (control group) respectively. The diagnosis, complications, and prognosis of patients were evaluated. The DVCT group provided high-resolution images with less processing and testing time, as well as lowered radiological agent and contrast agent compared with the control group. In the DVCT group, 89 patients who were diagnosed with venous ED had six various venous leakage, namely superficial venous leakage, profundus venous leakage, the mixed type, cavernosal venous leakage, crural venous leakage, and also venous leakage between the penis and urethra cavernosum (9, 21, 32, 6, 18, and 3 cases respectively). Similarly, 74 patients out of the 81 who suffered from venous ED were classified to have superficial venous leakage (11), profundus venous leakage (14), the mixed type venous leakage (26), and middle venous leakage (23). Six out of 25 patients in the DVCT group, had improvements in ED while the remaining 19 achieved full erectile function recovery with no penile fibrosis and erectile pain. Cavernosography with 320-row DVCT is a reliable system that can be used to diagnose ED caused by venous leakage. This is especially useful in accurately determining the type of venous and allows for a better prognosis and direction of treatment.

Interim 18F-FDG PET/CT improves the prognostic value of S-IPI, R-IPI and NCCN-IPI in patients with diffuse large B-cell lymphoma.

The current study aimed to explore whether the efficiency of the standard International Prognostic Index (S-IPI), revised-IPI (R-IPI) and enhanced-IPI (NCCN-IPI) in evaluating the prognosis of patients with diffuse large B-cell lymphoma (DLBCL) may be improved by interim 18F-FDG PET/CT. A total of 185 patients with newly diagnosed DLBCL were enrolled in the current study. All patients underwent interim PET/CT following the 4th cycle of chemotherapy. Patients were divided into different risk groups using S-IPI, R-IPI and NCCN-IPI and further subdivided into risk groups using interim PET/CT. Interpretations were evaluated for 2-year progression-free survival (PFS) and overall survival (OS). With a median follow-up time of 44 months, the 2-year PFS and OS were 60% [95% confidence interval (CI) 53-67%] and 81% (95% CI 74-86%), respectively. Analysis of S-IPI and NCCN-IPI identified no significant difference in PFS and OS between high intermediate and high risk groups. However, there were significant differences in the PFS and OS between the low and low intermediate risk groups (P<0.01). Interim PET/CT was used to redistribute patients in the higher risk group into PET negative and positive groups (P<0.01) and arallel results were observed in the lower risk group. In R-IPI, interim PET/CT identified a significant difference between PFS and OS in the good and poor risk groups but not in the very good risk group. Therefore, the results of the current study indicate that S-IPI, R-IPI and NCCN-IPI are three clinically useful prognostic indexes for patients with DLBCL. Interim PET/CT may improve the prognostic value of S-IPI, R-IPI and NCCN-IPI in predicting 2-year PFS and OS, particularly in patients with a high IPI score.

Primary diffuse large B-cell lymphoma of the left ureter: A case report.

Diffuse large B-cell lymphoma (DLBCL) is a subtype of non-Hodgkin lymphoma occurring in various sites, but rarely involving the ureters. Primary DLBCL is a rare entity. Imaging studies in a 82-year-old male patient revealed left hydronephrosis and an area of nodular soft tissue density in the upper ureteral wall. On enhanced computed tomography scans, the lesion exhibited early enhancement. As the lesion was considered to be malignant, a left nephroureterectomy was performed for the purpose of pathological diagnosis. Histological analysis and immunohistochemistry revealed DLBCL. Since the surgery, the patient has survived for 16 months without evidence of a relapse. Thus, in cases with ureteral stenosis or obstruction for which the cause is uncertain, the possibility of primary lymphoma of the ureter should be considered and further histopathological examination of bioptic samples should be performed as soon as possible.

Coronary Computed Tomographic Angiography at Low Concentration of Contrast Agent and Low Tube Voltage in Patients with Obesity:: A Feasibility Study.

RATIONALE AND OBJECTIVES: Using lower tube voltage can reduce the exposure to radiation and the dose of contrast agent. However, lower tube voltage is often linked to more noise and poor image quality, which create a need for more effective technology to resolve this problem. To explore the feasibility of coronary computed tomographic angiography (CCTA) in patients with obesity at low tube voltage (100 kV) and low contrast agent concentration (270 mg/mL) using iterative reconstruction. MATERIALS AND METHODS: A total of 48 patients with body mass index greater than 30 kg/m(2) were included and randomly divided into two groups. Group A received a traditional protocol (iopromide 370 mg/mL + 120 kV); group B received a protocol with low tube voltage (100 kV), low contrast agent concentration (270 mg/mL), and iterative reconstruction. The effective dose (ED), average attenuation values, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), the figure of merit (FOM), image quality scores, and the total iodine intake were compared. RESULTS: No significant differences in average CT attenuations, SNR, CNR, and subjective scores were noticed between the two groups (P > 0.05), whereas the FOM of group B was significantly higher than that of group A. Effective radiation dose, total iodine, and iodine injection rate in group B were lower than those of group A (P <0.01). CONCLUSIONS: In patients with obesity, isotonic contrast agent with low iodine concentration and low-dose CCTA were feasible. Substantial reduction in radiation dose and the iodine intake could be achieved without compromising the image quality.

Improved Image Quality and Decreased Radiation Dose of Lower Extremity Computed Tomography Angiography Using Low-Tube-Voltage and Adaptive Iterative Reconstruction.

OBJECTIVE: The aim of the study was to investigate the feasibility of low-tube-voltage computed tomography (CT) in combination with 3-dimensional adaptive iterative dose reduction (AIDR-3D) algorithm in lower extremity CT angiography. METHODS: The CT data of the 120-kV group (n = 30) were reconstructed with filtered back projection (FBP) algorithm. The CT data of the 100-kV group (n = 30) were reconstructed with FBP as well as AIDR-3D algorithms. RESULTS: The 100-kV group showed significantly lower dose-length product than the 120-kV group (P < 0.05). In comparison with the 120-kV and FBP protocol, the 100-kV and FBP protocol showed significantly increased vascular density and noise (P < 0.05). However, in the 100-kV group, images reconstructed with AIDR-3D showed significantly lower noise and significantly higher signal-to-noise ratio and contrast-to-noise ratio than FBP (P < 0.05). CONCLUSIONS: Low-tube-voltage (100 kV) 320-row CT in combination with AIDR-3D reconstruction can significantly improve the image quality and reduce radiation dose of lower extremity CT angiography.

Acute torsion of wandering spleen in a 17-year-old girl.

The acute torsion of wandering spleen is a very rare disease characterized by acute abdominal pain. Without early surgical intervention, wandering spleen can lead to splenic infarction or rupture. However, early clinical diagnosis is very difficult, so imaging modalities play an important role. We present a case of acute abdominal pain due to torsion of the wandering spleen in a 17-year-old girl, diagnosed by computed tomography and effectively managed by splenectomy for splenic infarction.

Stabilization of the Karenitecin® lactone by alpha-1 acid glycoprotein.

PURPOSE: Camptothecins contain a lactone ring that is necessary for antitumor activity, and hydrolysis of the lactone ring yields an inactive carboxylate species. Human serum albumin (HSA) and alpha-1 acid glycoprotein (AGP) are clinically significant plasma proteins thought to have important roles in camptothecin lactone stability. Herein, we examined the effect(s) of HSA and AGP on the lactone stability of Karenitecin, a novel, highly lipophilic camptothecin analog, currently at the phase 3 clinical testing stage. METHODS: An AGP-immobilized protein column was used to develop HPLC methods to evaluate the effect(s) of physiologically relevant HSA and AGP concentrations on the lactone/carboxylate ratio and hydrolysis kinetics of Karenitecin, camptothecin (CPT), and topotecan (TPT). RESULTS: Physiologically relevant concentrations of HSA and AGP substantially slowed Karenitecin lactone hydrolysis. AGP was notably more effective at protecting the Karenitecin lactone from hydrolysis than HSA was in promoting hydrolysis. Additionally, AGP reversed the hydrolysis of partially hydrolyzed Karenitecin lactone. In contrast, HSA and AGP had minimal effects on hydrolysis of the TPT lactone, while the AGP/HSA solutions dramatically accelerated hydrolysis of the CPT lactone. CONCLUSION: AGP strongly enhances the lactone stability of Karenitecin. Since Karenitecin is highly protein-bound in human plasma and exhibits greater lactone stability, relative to other camptothecins, in patient plasma samples, this newly identified role of AGP in promoting lactone stability may have important implications for the design of more effective anticancer agents within the Karentecin™ and camptothecin classes.