Detection of SARS-CoV-2 VOC-Omicron using commercial sample-to-answer real-time RT-PCR platforms and melting curve-based SNP assays.

Objectives: The World Health Organization (WHO) had designated the SARS-CoV-2 lineage B.1.1.529 as the new Variant of Concern Omicron (VOC-Omicron) on 26th November 20211. Real-time reverse transcription polymerase chain reaction (RT-PCR), single nucleotide polymorphisms (SNP) and whole genome sequencing (WGS) tests were widely employed to detect SARS-CoV-2 and its variant. Yet, the SARS-CoV-2 Omicron detection performance of commercial real-time RT-PCR platforms and SARS-CoV-2 spike SNP assays remain to be elucidated. Methods: In the first part of this study, we evaluated the VOC-Omicron detection performance of three commercial RT-PCR sample-to-answer platforms i.e. Roche cobas® 6800/8800, Roche cobas® Liat®, and Cepheid GeneXpert® systems. The detection performances were compared to one commercial conventional real-time RT-PCR assay (TIB MOLBIOL LightMix Modular SARS and Wuhan CoV E-gene) and one in-house real-time RT-PCR assay targeting RNA-dependent RNA polymerase (RdRP) gene of SARS-CoV-2 in the WHO COVID-19 Reference Laboratory at Public Health Laboratory Services Branch, Centre for Health Protection, Department of Health, The Government of the Hong Kong Special Administrative Region. In the second part of this study, we evaluated the SNP detection performance of four TIB MOLBIOL melting curve-based assays (1. Spike S371L/S373P, 2. Spike E484A, 3. Spike E484K and 4. Spike N501Y) in clinical samples obtained from hospitalized COVID-19 patients in Hong Kong. The SNP results were compared to whole genome sequences generated by Illumina platform. Results: The VOC-Omicron detection limits of three commercial sample-to-answer assays were tested to be ≤ 2.35 Log10 dC/ml. The detection performances of the sample-to-answer platforms were comparable to the two tested conventional real-time RT-PCR assays. The test sensitivities of TIB MOLBIOL VirSNiP SARS-CoV-2 Spike S371L/S373P assay and the Spike E484A assays were 100% and 96.6% respectively and the test specificities of both assays were 100%. An aberrant melting peak at Tm 42-44°C was observed when the specimens with Omicron variant were tested with the TIB MOLBIOL VirSNiP SARS-CoV-2 Spike E484K assay. Notably, the TIB MOLBIOL VirSNiP SARS-CoV-2 Spike N501Y assay failed to detect the spike N501Y mutation of Omicron variant in the tested specimens. Conclusions: The SARS-CoV-2 detection sensitivity of three commercial platforms, Roche cobas® 6800/8800, Roche cobas® Liat®, and Cepheid GeneXpert® systems were shown not to be impacted by the large number of mutations of VOC-Omicron. Also, the signature mutations i.e. Spike S371L/Spike S373P and Spike E484A in VOC-Omicron were correctly identified by the TIB MOLBIOL VirSNiP SARS-CoV-2 Spike S371L/S373P and VirSNiP SARS-CoV-2 Spike E484A assays. Unexpected findings including a shifted melting peak or absence of amplification curve/melting peak were observed when specimens with Omicron variant were tested with the TIB MOLBIOL VirSNiP SARS-CoV-2 Spike E484K assay and Spike N501Y assay, suggesting a potential alert for Omicron variant, prior confirmation by whole genome sequencing.

Core Temperature Lability Predicts Sympathetic Interruption and Cognitive Performance during Heat Exposure in Persons with Spinal Cord Injuries.

Among persons with high spinal cord injury (Hi-SCI: > T5), changes in core body temperature (Tcore) and cognitive performance during heat exposure appear related to degree of sympathetic interruption. Twenty men with Hi-SCI (C4-T4, American Spinal Injury Association Impairment Scale [AIS] A-B) and 19 matched, able-bodied controls were acclimated to 27°C baseline (BL) before exposure to 35°C heat challenge (HC). Two groups, differentiated by increase in Tcore during HC, were identified: high responders (HR-SCI: ΔTcore ≥0.5°C; n = 13, C4-T2) and low responders (LR-SCI: ΔTcore <0.5°C; n = 7, C4-T4). Tcore, distal skin temperatures (Tskavg), and distal microvascular perfusion (LDFboth feet) were measured, as were indices of sympathetic integrity, mean arterial pressure (MAP), and extremity sweat rate (SRavg). Cognitive performance was assessed at BL and post-HC, using the Stroop Color and Word and Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) Digit Span tests. At BL, Tcore of the HR-SCI group (36.6 ± 0.4°C) was lower than that for the LR-SCI (37.1 ± 0.3°C; p = 0.011) and control groups (37.3 ± 0.3°C; p < 0.001). After HC, Tcore was not different among groups. MAP of the HR-SCI group (70.9 ± 9.8 mm Hg) was lower than that of the LR-SCI (81.8 ± 7.0 mm Hg; p = 0.048) and control groups (89.9 ± 9.9 mm Hg; p < 0.001). SRavg increased more in the control group (77.0 ± 52.5 nL/cm2/min) than in the HR-SCI group (15.5 ± 22.0 nL/cm2/min; p = 0.001). Only the HR-SCI group had significant increases in T-Scores of Stroop Word (7.5 ± 4.4; p < 0.001), WAIS-IV Digit Span Sequence (1.9 ± 1.8; p = 0.002), and WAIS-IV Digit Span Total (1.4 ± 1.6; p = 0.008). Persons with SCI who responded to HC with a greater change in Tcore demonstrated evidence of greater sympathetic interruption and had an associated improvement in cognitive performance.

Effect of preoperative education and ICU tour on patient and family satisfaction and anxiety in the intensive care unit after elective cardiac surgery: a randomised controlled trial.

BACKGROUND: Preoperative education may help participants to psychologically prepare themselves for surgery, but the outcomes of such preparation have rarely been assessed in patients requiring postoperative care in the intensive care unit (ICU) as well as in family members. OBJECTIVE: To assess the effect of a preoperative multifaceted education intervention on patient and family satisfaction levels in the ICU and measures of perioperative patients' anxiety and depression. TRIAL DESIGN: Single-centre, two-armed, parallel, superiority, randomised controlled trial. Healthcare professionals in ICU and outcome assessor were blinded to treatment allocation. PARTICIPANTS: 100 elective coronary artery bypass grafting±valve surgery patients and their family members. INTERVENTIONS: Preoperative education comprising of a video and ICU tour in addition to standard care (treatment), versus standard care (control). OUTCOMES: Patient and family satisfaction levels with ICU using validated PS-ICU23 and FS-ICU24 questionnaires (0-100), respectively; change in perioperative anxiety and depression scores between 1 day presurgery and 3 days postsurgery. RESULTS: Among 100 (50 treatment, 50 control) patients and 98 (49 treatment, 49 control) family members, 94 (48 treatment, 46 control) patients and 94 (47 treatment, 47 control) family members completed the trial. Preoperative education was associated with higher overall patient (mean difference (MD) 6.7, 95% CI 0.2 to 13.2) and family (MD 10.0, 95% CI 3.8 to 16.3) satisfaction scores. There was a weak association between preoperative education and a reduction in patient's anxiety scores over time (MD -1.7, 95% CI -3.5 to 0.0). However, there was no evidence of a treatment effect on patient's depression scores over time (MD -0.6, 95% CI -2.3 to 1.2). CONCLUSION: Providing comprehensive preoperative information about ICU to elective cardiac surgical patients improved patient and family satisfaction levels and may decrease patients' anxiety levels. TRIAL REGISTRATION NUMBER: ChiCTR-IOR-15006971.

The Effect of Renal Replacement Therapy and Antibiotic Dose on Antibiotic Concentrations in Critically Ill Patients: Data From the Multinational Sampling Antibiotics in Renal Replacement Therapy Study.

BACKGROUND: The optimal dosing of antibiotics in critically ill patients receiving renal replacement therapy (RRT) remains unclear. In this study, we describe the variability in RRT techniques and antibiotic dosing in critically ill patients receiving RRT and relate observed trough antibiotic concentrations to optimal targets. METHODS: We performed a prospective, observational, multinational, pharmacokinetic study in 29 intensive care units from 14 countries. We collected demographic, clinical, and RRT data. We measured trough antibiotic concentrations of meropenem, piperacillin-tazobactam, and vancomycin and related them to high- and low-target trough concentrations. RESULTS: We studied 381 patients and obtained 508 trough antibiotic concentrations. There was wide variability (4-8-fold) in antibiotic dosing regimens, RRT prescription, and estimated endogenous renal function. The overall median estimated total renal clearance (eTRCL) was 50 mL/minute (interquartile range [IQR], 35-65) and higher eTRCL was associated with lower trough concentrations for all antibiotics (P < .05). The median (IQR) trough concentration for meropenem was 12.1 mg/L (7.9-18.8), piperacillin was 78.6 mg/L (49.5-127.3), tazobactam was 9.5 mg/L (6.3-14.2), and vancomycin was 14.3 mg/L (11.6-21.8). Trough concentrations failed to meet optimal higher limits in 26%, 36%, and 72% and optimal lower limits in 4%, 4%, and 55% of patients for meropenem, piperacillin, and vancomycin, respectively. CONCLUSIONS: In critically ill patients treated with RRT, antibiotic dosing regimens, RRT prescription, and eTRCL varied markedly and resulted in highly variable antibiotic concentrations that failed to meet therapeutic targets in many patients.

UK dental professionals' knowledge, experience and confidence when treating patients on the autism spectrum.

Background Over 1% of the UK population have a diagnosis of autism, and yet there is minimal information regarding the experiences of dental professionals working with people on the autistic spectrum. The current study is the first to investigate UK dental professionals' knowledge of autism, their perceived confidence when treating autistic patients, and the factors that affect this.Methods An online, self-report survey was completed by 482 UK dental professionals and included questions on participants' training, prior experiences and knowledge of autism, and confidence when treating autistic patients.Results Over half the respondents reported having no formal autism training but average knowledge levels across the whole sample were good. Conversely, levels of confidence were only moderate. Respondents often cited conflict between understanding the additional needs for successful treatment of autistic patients and a lack of resources to implement support strategies. Despite this, the vast majority were positive about making the necessary modifications to support autistic patients.Conclusion This study highlights ways in which UK dental professionals adapt their practices to meet the needs of their autistic patients, yet report only moderate confidence levels when doing so. Implications for future training initiatives are discussed.

Arterial embolization of retained kidney remnant following blunt traumatic injury: A case report.

INTRODUCTION: There has been a recent trend toward nonoperative management of solid organ injuries with arteriography and embolization as alternatives to surgical exploration. We examine the use of arterial embolization in the management of a post-subtotal nephrectomy urinoma in a patient with severe renal injury secondary to blunt trauma. METHODS: This case report has been reported in line with the CARE criteria [13]. PRESENTATION OF CASE: A 35-year-old female patient presented with a persistent urinoma after an incomplete nephrectomy for blunt renal trauma. Computed tomography scan of the abdomen demonstrated a 47×68×101 mm3 collection superior to the remnant of the resected right kidney. With persistence of the urinoma after placement of an 8 French drainage catheter, the patient was taken for arterial embolization of the lower renal artery for ablation of the kidney remnant. DISCUSSION: Most kidney injuries with urinoma formation are treated successfully with supportive measures, however refractory cases require intervention. Arterial embolization has been used successfully in the treatment of traumatic pseudoaneurysms, arteriovenous fistulas, and some renal tumors. In this patient, we extended the use of embolization to infarct vessels of the functioning kidney remnant as an alternative to surgery. Post-embolization the patient recovered well with permanent resolution of the urinoma and short-term side effects limited to short-lived fever and lumbar pain. CONCLUSION: Arterial embolization should be considered as an alternative to surgery in cases of persistent urinoma following renal trauma with retained remnants.

Patient and family satisfaction levels in the intensive care unit after elective cardiac surgery: study protocol for a randomised controlled trial of a preoperative patient education intervention.

INTRODUCTION: Patients and their families are understandably anxious about the risk of complications and unfamiliar experiences following cardiac surgery. Providing information about postoperative care in the intensive care unit (ICU) to patients and families may lead to lower anxiety levels, and increased satisfaction with healthcare. The objectives of this study are to evaluate the effectiveness of preoperative patient education provided for patients undergoing elective cardiac surgery. METHODS AND ANALYSIS: 100 patients undergoing elective coronary artery bypass graft, with or without valve replacement surgery, will be recruited into a 2-group, parallel, superiority, double-blinded randomised controlled trial. Participants will be randomised to either preoperative patient education comprising of a video and ICU tour with standard care (intervention) or standard education (control). The primary outcome measures are the satisfaction levels of patients and family members with ICU care and decision-making in the ICU. The secondary outcome measures are patient anxiety and depression levels before and after surgery. ETHICS AND DISSEMINATION: Ethical approval has been obtained from the Joint Chinese University of Hong Kong-New Territories East Cluster Clinical Research Ethics Committee (reference number CREC 2015.308). The findings will be presented at conferences and published in peer-reviewed journals. Study participants will receive a 1-page plain language summary of results. TRIAL REGISTRATION NUMBER: ChiCTR-IOR-15006971.

A rare case of splenic pseudoaneurysm in pediatric splenic blunt trauma patient: Review of diagnosis and management.

INTRODUCTION: Splenic pseudoaneurysms (SPA) are a rare but serious sequela of blunt traumatic injury to the spleen. Management of adult blunt splenic trauma is well-studied, however, in children, the management is much less well-defined. PRESENTATION OF CASE: A 15 year-old male presented with severe abdominal pain of acute onset after sustaining injury to his left side while playing football. FAST was positive for free fluid in the abdomen. Initial abdomen CT demonstrated a grade III/IV left splenic laceration with moderate to large hemoperitoneum with no active extravasation or injury to the splenic vessels noted. A follow-up CT angiography of the abdomen demonstrated a splenic hypervascular structure suspicious for a small pseudoaneurysm. Splenic arteriogram which demonstrated multiple pseudoaneurysms arising from the second order splenic artery branches which was angioembolized and treated. DISCUSSION & CONCLUSION: Questions still remain regarding the timing of repeat imaging for diagnosis of SPA following non-operative blunt splenic trauma, which patients should be imaged, and how to manage SPA upon diagnosis. More clinical study and basic science research is warranted to study the disease process of SPA in pediatric patient. We believe that our proposed management algorithm timely detect formation of delayed SPA formation and addresses the possible fatal disease course of pediatric SPA.

Attitudes towards ethical problems in critical care medicine: the Chinese perspective.

INTRODUCTION: Critical care doctors are frequently faced with clinical problems that have important ethical and moral dimensions. While Western attitudes and practice are well documented, little is known of the attitudes or practice of Chinese critical care doctors. METHODS: An anonymous, written, structured questionnaire survey was translated from previously reported ethical surveys used in Europe and Hong Kong. A snowball method was used to identify 534 potential participants from 21 regions in China. RESULTS: A total of 315 (59%) valid responses were analysed. Most respondents (66%) reported that admission to an intensive care unit (ICU) was commonly limited by bed availability, but most (63%) would admit patients with a poor prognosis to ICU. Only 19% of respondents gave complete information to patients and family, with most providing individually adjusted information, based on prognosis and the recipient's educational level. Only 28% disclosed all details of an iatrogenic incident, despite 62% stating that they should. The use of do not resuscitate orders or limitation of life-sustaining therapy in terminally ill patients reported as uncommon and according to comparable reports, both are more common practice in Hong Kong or Europe. In contrast to European practices, doctors were more acquiescent to families in decision-making at the end of life. CONCLUSIONS: A number of differences in ethical attitudes and related behaviour between Chinese, Hong Kong and European ICU doctors were documented. A likely explanation is differing cultural background, and doctors should be aware of likely expectations when treating patients from a different culture.

The incidence of deep venous thrombosis in Chinese medical Intensive Care Unit patients.

OBJECTIVE: To evaluate the incidence of deep venous thrombosis in critically ill, Intensive Care Unit patients of Chinese ethnicity. DESIGN: Prospective, observational study. SETTING: Intensive Care Unit in a Hong Kong teaching hospital. PATIENTS: Consecutive adult Chinese medical patients not receiving pharmacological or mechanical prophylaxis for deep venous thrombosis. MAIN OUTCOME MEASURES: Compression and duplex Doppler ultrasound examinations of the lower limbs within 24 hours of admission and twice weekly thereafter during their Intensive Care Unit stay. After discharge, a 1-week follow-up investigation was also performed. Demographic data and risk factors for deep venous thrombosis were prospectively recorded. RESULTS: Over a 9-month study period, 80 patients were investigated. Deep venous thrombosis was detected by ultrasound examination in 15 (19%) of the patients (95% confidence interval, 14-23%). Nine of 15 had isolated below-knee deep venous thrombosis, and of these, five had bilateral involvement. Characteristics of patients with or without deep venous thrombosis were similar. Of the 15 patients who had a positive ultrasound examination, only four (27%) had clinical signs of deep venous thrombosis. Of the 65 patients without a positive ultrasound examination, only two (3%) had positive clinical signs (P=0.01). This yielded a moderate positive likelihood ratio of 9 (95% confidence interval, 2-43) and a small negative likelihood ratio of 0.76 (95% confidence interval, 0.56-1.03). There were no cases of pulmonary embolism. Hospital mortality in those with and without deep venous thrombosis was 33% and 28%, respectively. CONCLUSIONS: In the absence of prophylaxis, the incidence of deep venous thrombosis in Chinese medical Intensive Care Unit patients is lower than that reported in similar Caucasian patients, but higher than expected. As clinical features are not able to reliably exclude the presence of deep venous thrombosis, early routine prophylaxis for deep venous thrombosis in Chinese medical Intensive Care Unit patients should be considered.

Randomized controlled trial comparing adaptive-support ventilation with pressure-regulated volume-controlled ventilation with automode in weaning patients after cardiac surgery.

BACKGROUND: Adaptive-support ventilation (ASV) is a minute ventilation-controlled mode governed by a closed-loop algorithm. With ASV, tidal volume and respiratory rate are automatically adjusted to minimize work of breathing. Studies indicate that ventilation in ASV enables more rapid weaning. The authors conducted a randomized controlled trial to determine whether ventilation in ASV results in a shorter time to extubation than pressure-regulated volume-controlled ventilation with automode (PRVCa) after cardiac surgery. METHODS: Fifty patients were randomly assigned to ASV or PRVCa after elective coronary artery bypass grafting. Respiratory weaning progressed through three phases: phase 1 (controlled ventilation), phase 2 (assisted ventilation), and phase 3 (T-piece trial), followed by extubation. The primary outcome was duration of intubation (sum of phases 1-3). Secondary outcomes were duration of mechanical ventilation (sum of phases 1 and 2), number of arterial blood gas samples, and manual ventilator setting changes made before extubation. RESULTS: Forty-eight patients completed the study. The median duration of intubation was significantly shorter in the ASV group than in the PRVCa group (300 [205-365] vs. 540 [462-580] min; P < 0.05). This difference was due to a reduction in the duration of mechanical ventilation (165 [120-195] vs. 480 [360-510] min; P < 0.05). There were no significant differences between the ASV and PRVCa groups in the number of arterial blood gas samples taken or manual ventilator setting changes made. CONCLUSIONS: ASV is associated with earlier extubation, without an increase in clinician intervention, when compared with PRVCa in patients undergoing uncomplicated cardiac surgery.

The adsorption of vancomycin by polyacrylonitrile, polyamide, and polysulfone hemofilters.

The aim of this study was to characterize vancomycin adsorption by polyacrylonitrile (PAN), polyamide, and polysulfone hemofilters using an in vitro model of hemofiltration. Vancomycin (36 mg) was added to a blood-crystalloid mixture of known volume (target concentration of 50 mg/L) and pumped around a closed circuit. Adsorption, which was calculated from the fall in concentration over 120 min, was significantly greater by 0.6-m(2) PAN filters (10.08 +/- 2.26 mg) than by 0.6-m(2) polyamide (5.20 +/- 1.82 mg) or 0.7-m(2) polysulfone (4.80 +/- 2.40 mg) filters (P < 0.05). Cumulative adsorption was not changed by the addition of 500-mL lactated Ringer's solution (to reduce the circulating vancomycin concentration). These data show that although adsorption of vancomycin by PAN, polyamide, and polysulfone hemofilters occurs, the absolute adsorption is small. Adsorption is dependent on filter material and is not reversed by a decrease in circulating concentration.

Effect of drug concentration on adsorption of levofloxacin by polyacrylonitrile haemofilters.

We studied an in vitro model of continuous venovenous haemofiltration to determine levofloxacin adsorption by polyacrylonitrile (PAN) filters. Four doses of levofloxacin (5, 25, 50 and 100 mg) were used, resulting in circulating concentrations of levofloxacin at 120 min of 3.56+/-0.14, 15.84+/-2.08, 31.42+/-1.95 and 58.23+/-1.10 mg/L, respectively. Adsorption at 2 h was 0.65+/-0.17, 5.99+/-2.49, 12.30+/-2.34 and 30.13+/-1.32 mg, respectively (P<0.001). From 2h to 4h, increasing the blood pump rate and the ultrafiltration rate had no effect on adsorption. When the concentration was decreased from 3.55+/-0.13 mg/L at 4h to 2.16+/-0.11 mg/L at 5 h by addition of lactated Ringer's solution, adsorption decreased from 0.67+/-0.16 mg to 0.21+/-0.25 mg (P<0.05). These data show that adsorption of levofloxacin by PAN haemofilters is concentration dependent and reversible in vitro and suggest that adsorption by haemofilters is unlikely to affect levofloxacin pharmacokinetics significantly in vivo.

Transmission of SARS to healthcare workers. The experience of a Hong Kong ICU.

OBJECTIVE: To describe the extent and temporal pattern of transmission of severe acute respiratory syndrome (SARS) to intensive care unit staff. DESIGN: Retrospective observational cohort study. SETTING: University hospital intensive care unit, caring solely for patients with SARS or suspected to have SARS. PARTICIPANTS: Thirty-five doctors and 152 nurses and healthcare assistants who worked in the ICU during the SARS epidemic. INTERVENTIONS: Infection control measures designed to prevent transmission of disease to staff were implemented. MEASUREMENTS AND RESULTS: Sixty-seven patients with SARS were admitted to the intensive care unit. Four nurses and one healthcare assistant contracted SARS, with three of these developing symptoms within 10 days of admission of the first patient with SARS. Doctors were exposed to patients with SARS for a median (IQR) of 284 (97-376) h, while nurses and healthcare assistants were exposed for a median (IQR) of 119 (57-166) h. The ICU did not meet international standards for physical space or ventilation. CONCLUSIONS: In an ICU in which infection control procedures are rigorously applied, the risk to staff of contracting SARS from patients is low, despite long staff exposure times and a sub-standard physical environment.

Long-term outcome of acute respiratory distress syndrome caused by severe acute respiratory syndrome (SARS): an observational study.

OBJECTIVE: We examined long-term outcome of pulmonary function, exercise capacity and health-related quality of life (HRQoL) in patients with acute respiratory distress syndrome (ARDS) caused by severe acute respiratory syndrome (SARS). METHODS: 59 critically ill patients with ARDS caused by SARS between March and July 2003 were studied prospectively and followed up for 1 year. Thirty-six underwent pulmonary function testing and a 6-minute walk test, and 35 underwent HRQoL evaluation by Short Form-36 questionnaire at 3, 6, and 12 months after illness onset. RESULTS: Mean age was 47 (SD, 15.7) years. Median APACHE II score was 10 (interquartile range [IQR], 7-12). Only 47% required invasive mechanical ventilation. Median admission and worst PaO2/FIO2 ratio were 142 (IQR, 94-177) mmHg and 86 (IQR, 66-122) mmHg, respectively. Median stay in ICU and hospital were 9 (IQR, 5-20) and 31 (IQR, 20-54) days, respectively. Mortality was 24% at hospital discharge and at 1 year. Mean lung volumes and spirometric measurements were nearly normal by 6 months. Except for diffusion capacity adjusted for haemoglobin concentration (DLCO) measured at 12 months, there was no significant difference in pulmonary function measurement between those who had mechanical ventilation and those who did not. The 6-minute walk distance (6MWD) improved from 3 to 6 months, with no further significant change. Younger patients had near normal HRQoL by 6 months. Those aged over 40 years had impaired HRQoL at multiple domains even at 12 months. At 12 months, forced expiratory volume in 1 second, forced vital capacity and 6MWD correlated significantly with multiple SF-36 domain scores. DLCO correlated significantly only with domain scores reflecting physical function. CONCLUSIONS: The mortality of SARS-related ARDS is similar to the mortality of ARDS from other causes. A substantial number of patients with SARS-related ARDS survived without receiving mechanical ventilation. Patients had good recovery of pulmonary function and HRQoL.

The effect of adsorption, filter material and point of dilution on antibiotic elimination by haemofiltration an in vitro study of levofloxacin.

We studied an in vitro model of continuous venous-venous haemofiltration (CVVH), into which levofloxacin 100 mg was infused, to determine levofloxacin adsorption and to determine the effect of filter material and point of dilution (pre- or post-filter) on sieving coefficient. Mean (standard deviation; S.D.) adsorption was 18.7 (5.3) mg for the polyamide filter and 40.2 (2.0) mg for the polyacrylonitrile (PAN) filter (P < 0.001). Post-dilution resulted in a minor, but statistically significant, decrease in sieving coefficient (pre-dilution 0.96 (S.D. 0.10), post-dilution 0.88 (S.D. 0.11) with the PAN filter. These data indicate that the variability in published values for levofloxacin sieving coefficient are not due to variation in point of dilution or membrane type (PAN or polyamide). Significant adsorption of levofloxacin onto PAN filters occurs.

Gene expression analysis of an integrin family of genes by systematic multiplex reverse transcription-polymerase chain reaction.

We have established the systematic multiplex reverse transcription-polymerase chain reaction (SM RT-PCR) system of 26 members of the integrin family of genes, and used this system to investigate their expression in 25 different kinds of human adult tissues. A hierarchical clustering analysis of the tissue expression data illustrated clustering of functionally related tissues. Although the correlation was weak, bone marrow, thymus, and spleen were clustered, potentially confirming the role of certain integrin molecules in the immune response. We also investigated changes in integrin gene expression in cancer. Several differences were observed between normal and tumor, as well as between normal and cancer cell lines. The SM RT-PCR experiments for the study of alternative splicing showed that most of the integrin genes analyzed exhibited fixed ratios of differentially spliced transcripts probably due to a tissue-independent mechanism of splicing predetermined by the nucleotide sequences around the splicing donor and acceptor sites.