The effect of handedness on mental rotation of hands: a systematic review and meta-analysis.

Body-specific mental rotation is thought to rely upon internal representations of motor actions. Handedness is a source of distinctly different motor experience that shapes the development of such internal representations. Yet, the influence of handedness upon hand mental rotation has never been systematically evaluated. Five databases were searched for studies evaluating hand left/right judgement tasks in adults. Two independent reviewers performed screening, data extraction, and critical appraisal. Eighty-seven datasets were included, with 72 datasets pooled; all had unclear/high risk of bias. Meta-analyses showed that right-handers were faster, but not more accurate, than left-handers at hand mental rotation. A unique effect of handedness was found on performance facilitation for images corresponding to the dominant hand. Meta-analyses showed that right-handers were quicker at identifying images of right hands than left hands-a dominance advantage not evident in left-handers. Differing hand representations (more lateralised hand dominance in right-handers) likely underpin these findings. Given potential differences between hand preference and motor performance, future research exploring their distinct contributions to mental rotation is warranted.

Incidence and treatment of positive pelvic sidewall lymph nodes in patients with rectal cancer.

AIM: The involvement of pelvic sidewall (PSW) lymph nodes in rectal cancer is a marker of locally advanced disease and poor prognosis. Eastern countries generally advocate lateral lymph node dissection (LLND) over the Western approach of neoadjuvant chemoradiotherapy and more limited surgery. The aim of this study was to evaluate how these advanced cancers were treated in three UK Health Boards. METHODOLOGY: This was a retrospective review of three colorectal multidisciplinary team meetings from 2008 to 2016. All patients with rectal cancer and suspicious PSW lymph nodes on pretreatment MRI were included. RESULTS: There were 153 (6.2%) patients who met the inclusion criteria from a total of 2461 diagnosed rectal cancers. There was significant variability between the three centres with surgical intervention ranging from 59.2% to 84.4%, P = 0.015. There were 81 patients who had neoadjuvant chemoradiotherapy prior to surgery; of these 67 (82.7%) still had positive PSW nodes on the restaging MRI, but only 13 (19.4%) had LLND. There was no difference in local recurrence (15.3% vs 11.8%, P = 0.66), 5-year overall survival (69.2% vs 80.1%, P = 0.16) or 5-year disease-free survival (69.2% vs 79.4%, P = 0.72) between patients having LLND and those receiving standard neoadjuvant treatment followed by total mesorectal excision surgery. CONCLUSIONS: This study has demonstrated that rectal cancer patients with PSW positive nodal disease have advanced disease, mostly of the lower rectum, and receive a highly heterogeneous spectrum of therapies, even within a relatively small geographical area. Greater accuracy in our preoperative staging is needed to select those patients who will benefit from LLND surgery.

Thrombocytosis as a Marker for Postoperative Complications in Colorectal Surgery.

BACKGROUND: Blood platelet measurement is a widely available and inexpensive test that is performed routinely. Platelets are thought to act by inducing inflammation and play a role in clotting and antimicrobial defence. A postoperative rise in the platelet count (thrombocytosis) is often dismissed as an incidental finding, but there is growing evidence to suggest that it may act as an indicator to underlying pathology. It correlates with significant pyogenic infections as well as multiple malignancies. In addition to this, recent research indicates that thrombocytosis may be a useful prognostic indicator for postoperative outcomes in patients with malignancies. In patients undergoing surgery for gastric cancer, a combination of platelet count and neutrophil-to-lymphocyte (NLR) ratio collected preoperatively was shown to correlate with postoperative survival. OBJECTIVE: To evaluate whether there is a positive correlation between pre- and postoperative thrombocytosis and the risk of complications following colorectal surgery. METHODS: This was a retrospective observational study based in Morriston Hospital, Swansea. Patients undergoing elective colorectal surgery for an 18-month period between 2014 and 2016 were included. Data on patient demographics, pre- and postoperative platelet count, the first date at which the highest platelet count was recorded, length of stay, type of operation, and postoperative complications using the Clavien-Dindo classification was obtained from the theatre booking software (TOMS) and Welsh Clinical Portal. Pearson's chi-square test was used for the analysis of the categorical variables. RESULTS: Of the 201 patients studied, 75 (37%) had postoperative thrombocytosis (platelets ≥ 500 × 109/L, range 501-1136), 120 (59%) had postoperative normocytosis (platelets < 500 × 109/L, range 107-499), and 6 (2.9%) patients were excluded due to insufficient data. Peak platelet level was seen at a median of 8 days postoperatively but ranged from days 1 to 49. In patients with thrombocytosis, the mean time to peak platelet count was 9.5 days and ranged 1 to 49 days. 101/195 (52%) patients had a Clavien-Dindo III/V postoperative complication: 63% patients with postoperative normocytosis and 24% with postoperative thrombocytosis. In the thrombocytosis group, 16/75 (21%) were found to have postoperative pelvic collections compared to 1/120 (0.8%) of the normocytic patients. The total percentage of medical complications (44% versus 20%, p = 0.006) and surgical complications (64% versus 15.8%, p = 0.0001) was higher in the thrombocytosis group compared to the normocytosis group. CONCLUSION: In this retrospective study, thrombocytosis was shown to have a positive correlation with postoperative medical and surgical complications. An elevated platelet count in the postoperative period should alert the clinician to a developing complication. We recommend that further studies with a larger sample size would test the specific associations with individual complications.

Inflammatory cell ratios predict major septic complications following rectal cancer surgery.

INTRODUCTION: The inflammatory response is known to have an important role in tumourigenesis and the response to treatment. Previous studies have demonstrated that inflammatory cell ratios such as the neutrophil-to-lymphocyte ratio (NLR) can predict survival and recurrence following surgery for various cancers. The objective of this study was to demonstrate if pre-operative NLR has a role in predicting post-operative septic complications in patients undergoing rectal cancer surgery. METHODOLOGY: Consecutive patients undergoing scheduled resection for rectal cancer in a tertiary centre from July 2007 to Dec 2015 were included. Data was gathered from a prospectively held database of rectal cancer. Normally distributed data were compared with paired t tests (mean ± standard error in the mean (SEM)), and proportions were compared with Fisher's exact test. A p value of < 0.05 was considered statistically significant. RESULTS: Three hundred fourteen patients were identified in this study. Sixty nine (22.0%) patients had a major septic complication following surgery for rectal cancer, which was associated with a poor survival outcome (p < 0.01) Both pre and post-operative NLR and PLR (platelet lymphocyte ratio) were associated with post-operative septic complications (both p < 0.01). A pre-operative NLR threshold level of 4 was chosen from ROC analysis, and this provided a relatively specific test to predict post-operative septic complications in these patients (specificity = 83.7%, negative predictive value (NPV) = 74.8%). DISCUSSION: In this study, the pre-operative NLR and PLR were both predictive of major post-operative septic complications. A pre-operative NLR of less than 4 was strongly negative predictor of post-operative complications in rectal cancer surgery. It can be regarded as a predictive and prognostic factor for these patients.

Inguinal hernias associated with a single strenuous event.

INTRODUCTION: There is debate regarding the role of physical activity and, in particular, a single strenuous event (SSE) in the development of inguinal hernia. This study aims to identify the incidence and associated features of hernias perceived to be due to a single strenuous event and to compare their features with published guidelines. MATERIALS AND METHODS: All consecutive patients surgically treated for primary inguinal hernia at a single NHS trust between April 2010 and April 2011 were identified and contacted to participate in a questionnaire. Clinical details from operative records and case notes were compared with patients' responses to identify features of their presentation attributable to a single strenuous event according to previously published guidelines. RESULTS: Three hundred and thirty five eligible patients were contacted with a response rate of 292 (87 %). 41/292 (14 %) of patients reported an SSE associated with the onset of their hernia. Only 2 of 41 (5 %) patients reporting a hernia associated with SSE met published criteria for association of the hernia with SSE, and this represented less than 1 % of all patients treated for inguinal hernia at a single centre in a 1-year period. CONCLUSION: The relationship between physical activity and development of inguinal hernia is under debate; however, we find that inguinal hernia that can be attributed to SSE is a rare event, despite the fact that many patients present with acute symptoms. Updated guidelines for the assessment of 'cause' in industrial claims for the association of hernia with workplace activity are required.

Social deprivation in patients requiring pelvic exenterative surgery.

AIM: Pelvic exenteration is an aggressive operation for locally advanced rectal cancer. Social deprivation has been shown to reduce life expectancy and has been linked to a poorer outcome in patients with colorectal cancer. The aim of this study was to analyse the effect of social deprivation scores on the outcome in these complex patients. METHOD: A retrospective review of all patients undergoing pelvic exenteration for primary rectal cancer between 2006 and 2014 was performed. Deprivation scores were calculated for all patients using the Welsh Index of Multiple Deprivation. Patients were then grouped into quartiles, from Q1 (most deprived) to Q4 (least deprived). The primary outcome measure was 5-year survival. RESULTS: In all, 120 patients were included (65 female) with a median age of 64 (31-90) years. No differences between quartiles were identified for neoadjuvant therapy (P = 0.687) or type of exenteration (P = 0.690). The median length of stay was significantly higher in the most deprived groups (Q1-Q2; P = 0.023). There was a significant difference in survival between the groups, with lowest 5-year survival rates (53%) in the most deprived quartile (Q1) (P = 0.015). CONCLUSION: Social deprivation is significantly associated with postoperative length of stay and survival in patients undergoing pelvic exenteration for primary rectal cancer.

Determinants of survival following pelvic exenteration for primary rectal cancer.

BACKGROUND: Pelvic exenteration is a potentially curative treatment for locally advanced primary rectal cancer. Previous studies have been limited by small sample sizes and heterogeneous data. A consecutive series of patients was studied to identify the clinicopathological determinants of survival. METHODS: All patients undergoing pelvic exenterative surgery for primary rectal cancer (1992-2014) at this hospital were analysed. The primary outcome measure was 5-year overall survival. Secondary endpoints included length of hospital stay, complication rate, 30-day mortality and disease recurrence rate. Statistical analysis was performed using Kaplan-Meier and Cox regression analysis. RESULTS: A total of 174 patients with a median age of 65 (range 31-90) years were included. Ninety-six patients underwent posterior pelvic exenteration and 78 had total pelvic exenteration. Median follow-up was 48 (range 1-229) months. Two patients (1.1 per cent) died within 30 days of surgery and 16.1 per cent returned to the operating theatre. The 5-year survival rate following complete resection (R0) was 59.3 per cent. In univariable analysis, adverse survival was associated with advanced age (P = 0.003), metastatic disease (P = 0.001), pathological node status (P = 0.001), circumferential resection margin (P = 0.001), local recurrence (P = 0.015) and the need for neoadjuvant therapy (P = 0.039). CONCLUSION: Pelvic exenteration is an aggressive treatment option with a high morbidity rate that provides favourable long-term outcomes in patients with locally advanced primary rectal cancer.

Conservative management of vestibular schwannomas of 15 to 31 mm intracranial diameter.

OBJECTIVE: To study the natural course of vestibular schwannomas 15 to 31 mm in diameter. METHODS: A retrospective study of 45 patients conservatively managed with interval scanning was performed. Outcome measures were: changes in tumour size, clinical features and hearing. A tumour was considered to be growing if it increased in size by more than 2 mm. RESULTS: Initial tumour sizes ranged from 15 to 31 mm, with a mean (± standard deviation) diameter of 20.1 ± 4.3 mm. The duration of follow up ranged from 6 months to 14 years (median, 3 years). Tumours grew in 11 cases (24.4 per cent), remained stable in 30 cases (66.7 per cent) and regressed in 4 cases (8.9 per cent). The overall mean tumour growth rate was 0.9 ± 2.2 mm per year; in growing tumours, it was 3.6 ± 2.9 mm per year. CONCLUSION: Outcomes were similar to those reported for smaller tumours. These findings suggest that patients with medium or moderately large tumours can be safely offered an initial period of conservative management before intervention is considered.

Outcomes in locally advanced rectal cancer with highly selective preoperative chemoradiotherapy.

BACKGROUND: This study compared outcomes after surgery alone for stage II/ III rectal cancer in a tertiary cancer unit versus highly selective use of preoperative chemoradiotherapy (CRT). METHODS: This was a single-centre retrospective cohort study of consecutive patients receiving potentially curative surgery for stage II and III primary rectal cancer. CRT was given only for magnetic resonance imaging-predicted circumferential resection margin (CRM) involvement and nodal disease (at least N2). Primary endpoints were CRM involvement and local recurrence rates. Secondary endpoints were systemic recurrence and overall survival. Data were analysed by log rank test, and univariable and multivariable analysis. RESULTS: Between 2002 and 2012, 363 patients were treated for rectal cancer. After applying exclusion criteria, 266 patients with stage II/III mid or low rectal cancer were analysed. Of these, 103 received neoadjuvant CRT and 163 proceeded directly to surgery, seven of whom required postoperative radiotherapy; the latter patients were included in the neoadjuvant CRT group for analysis. There was a significant difference in local recurrence between the CRT and surgery-alone groups (6·5 versus 0 per cent at 5 years; P = 0·040), but not in CRM involvement (7·2 versus 5·1 per cent; P = 0·470), 5-year systemic recurrence (37·2 versus 43·0 per cent; P = 0·560) and overall survival (64·2 versus 64·6 per cent; P = 0·628) rates. Metastatic disease developed more frequently in low rectal cancers (odds ratio 0·14; P < 0·001), regardless of whether neoadjuvant treatment was delivered. CONCLUSION: Locally advanced rectal cancer does not necessarily require neoadjuvant CRT.

Investigation of slice thickness and shape milled by a focused ion beam for three-dimensional reconstruction of microstructures.

Three-dimensional reconstructions of microstructures produced by focused ion beam (FIB) milling usually assume a uniform slice thickness with flat and parallel surfaces. Measurement of the actual slice thickness and profile is difficult, and is often simply ignored. This paper reports the use of artificial 3D structures of known geometry to enable the full 3D profile of a sequence of slices produced by FIB to be measured for the first time. A transient period at the beginning of a milling process is observed in which the actual slice thickness varies by as much as ±50% from the target thickness (with significantly greater error near the base of the slice), before settling to a ±20% variation as the milling progresses. Although SEM images appear to show flat milled surfaces perpendicular to the top surface, the development of a curved, tapering milled surface is also observed. This profile is then maintained through the milling process with the bottom of the slice lagging the top by up to three slice thicknesses.

Metrological challenges for reconstruction of 3-D microstructures by focused ion beam tomography methods.

The development of combined focused ion beam and scanning electron microscopes has enabled significant advances in the characterization of the 3-D structure of materials. The repeated removal of thin layers or slices with an ion beam and imaging or mapping the chemical or crystallographic structure of each slice enables a 3-D reconstruction from the images or maps. The accuracy of the reconstruction thus depends on the accuracy with which the slice thickness is measured and maintained throughout the process, and the alignment accuracy of the slices achieved during acquisition or by postacquisition corrections. A survey of papers published in this field suggests that the reconstruction accuracy is not often considered or reported. Using examples from examination of the 3-D structure of hardmetals, issues affecting the accuracy of slice thicknesses and image realignments are examined and illustrated and potential errors quantified by the use of fiducial markers and the expected isotropy of the hardmetal structure itself.

Can root electrical capacitance be used to predict root mass in soil?

BACKGROUND: Electrical capacitance, measured between an electrode inserted at the base of a plant and an electrode in the rooting substrate, is often linearly correlated with root mass. Electrical capacitance has often been used as an assay for root mass, and is conventionally interpreted using an electrical model in which roots behave as cylindrical capacitors wired in parallel. Recent experiments in hydroponics show that this interpretation is incorrect and a new model has been proposed. Here, the new model is tested in solid substrates. METHODS: The capacitances of compost and soil were determined as a function of water content, and the capacitances of cereal plants growing in sand or potting compost in the glasshouse, or in the field, were measured under contrasting irrigation regimes. KEY RESULTS: Capacitances of compost and soil increased with increasing water content. At water contents approaching field capacity, compost and soil had capacitances at least an order of magnitude greater than those of plant tissues. For plants growing in solid substrates, wetting the substrate locally around the stem base was both necessary and sufficient to record maximum capacitance, which was correlated with stem cross-sectional area: capacitance of excised stem tissue equalled that of the plant in wet soil. Capacitance measured between two electrodes could be modelled as an electrical circuit in which component capacitors (plant tissue or rooting substrate) are wired in series. CONCLUSIONS: The results were consistent with the new physical interpretation of plant capacitance. Substrate capacitance and plant capacitance combine according to standard physical laws. For plants growing in wet substrate, the capacitance measured is largely determined by the tissue between the surface of the substrate and the electrode attached to the plant. Whilst the measured capacitance can, in some circumstances, be correlated with root mass, it is not a direct assay of root mass.

An approach to the determination of winter chill requirements for different Ribes cultivars.

Winter chilling is critical for flowering and fruiting of many temperate fruits, with evidence that blackcurrant (Ribes nigrum L.) cropping has been adversely affected by warm winters. Accurate models of chill accumulation in blackcurrant are required so that breeding strategies can be formulated for the generation of new cultivars with resilience to future climates. Existing models for chill accumulation have largely been derived from statistical correlation; here we report the derivation of improved models for blackcurrant using controlled environment treatments. Hardwood cuttings from a diverse set of cultivars were exposed to constant or varying chilling temperatures and the effects on bud break after transfer to a warm, permissive environment evaluated. The impact of different combinations of temperature and chilling periods were described in terms of their overall 'Effectiveness' (E). Clear genotypic differences were found, with excessive chilling often inhibiting bud break. There was a significant interaction between observed chilling response and the period of low temperature exposure. A number of chilling models to explain observed interactions between chilling temperature and time of exposure on bud break were compared; the most effective involved an optimal response to increasing chill accumulation. The effects of varying temperatures during chilling on bud break were complex, with warm temperature breaks substantially inhibiting bud development and cooler temperature breaks tending to enhance bud burst. The relevance of these models to generic studies of endodormancy is discussed, together with their potential application to the development of phenotyping screens for future breeding using diverse blackcurrant germplasm.

A perforated duodenal ulcer presenting as inferior lead ST elevation following amphetamine use.

Typical symptoms of duodenal ulcers include epigastric pain, nausea, vomiting, chest pain and shortness of breath. Here we present the case of a 39-year-old man who had a sudden onset of chest and epigastric pain following the use of recreational amphetamines. There were ST changes in the inferior leads of his electrocardiogram, indicating the possibility of a myocardial infarction. Following double contrast computed tomography of the abdomen and an urgent laparotomy, a diagnosis of a perforated duodenal ulcer was made. We discuss the aetiologies, presentation, investigation and treatment of the disorder, and make recommendations on the management.

Congenital diaphragmatic hernia: an unusual cause of obstructive jaundice.

Congenital diaphragmatic hernias in adults are exceedingly rare. They have been reported to cause dyspnoea, gastric reflux and intestinal obstruction. We present the case of a young woman with obstructive jaundice secondary to a Bochdalek hernia of the right hemidiaphragm. We discuss the aetiologies, presentation, investigation and treatment of the disorder, and make recommendations on the management.

Clinimetrics of tristimulus colourimeters in scar assessment: a review of evidence.

OBJECTIVE: To review the evidence regarding the use of tristimulus colourimeters (TC) in scar assessment. METHOD: A literature search was performed using Ovid and the Cochrane database with the search terms 'scar assessment', 'clinimetrics', 'tristimulus colourimeter', 'microcolour', 'chromameter' and 'colour spectrometer'. RESULTS: Wound colour is usually assessed with a visual analogue scale, such as VSS or POSAS. Research on objectifying the assessment by using an assessment tool has so far been encouraging, but has failed to show a benefit over the visual analogue scales in terms of validity, accuracy and reproducibility. Studies vary in methodological quality. CONCLUSION: Research on TC clinimetrics has shown moderate to high concurrent validity, reliability and reproducibility of these products in terms of assessing vascularity, but less correlation in terms of pigmentation, when compared with the visual scoring systems. The evidence for using TC is based on a relatively small number of studies, and more research is needed before widespread implementation of TC for assessing scar maturation is recommended.

Continuous cervical plexus block for carotid body tumour excision in a patient with Eisenmenger's syndrome.

A patient with Eisenmenger's syndrome presented for removal of a carotid body tumour. Continuous cervical plexus blockade was successfully used to provide peri-operative and postoperative analgesia. The risks and benefits of regional and general anaesthesia in this high risk patient are discussed.

Estimating stomatal conductance with thermal imagery.

Most thermal methods for the study of drought responses in plant leaves are based on the calculation of 'stress indices'. This paper proposes and compares three main extensions of these for the direct estimation of absolute values of stomatal conductance to water vapour (gs) using infrared thermography (IRT). All methods use the measured leaf temperature and two environmental variables (air temperature and boundary layer resistance) as input. Additional variables required, depending on the method, are the temperatures of wet and dry reference surfaces, net radiation and relative humidity. The methods were compared using measured gs data from a vineyard in Southern Portugal. The errors in thermal estimates of conductance were of the same order as the measurement errors using a porometer. Observed variability was also compared with theoretical estimates of errors in estimated gs determined on the basis of the errors in the input variables (leaf temperature, boundary layer resistance, net radiation) and the partial derivatives of the energy balance equations used for the gs calculations. The full energy balance approach requires accurate estimates of net radiation absorbed, which may not be readily available in field conditions, so alternatives using reference surfaces are shown to have advantages. A new approach using a dry reference leaf is particularly robust and recommended for those studies where the specific advantages of thermal imagery, including its non-contact nature and its ability to sample large numbers of leaves, are most apparent. Although the results suggest that estimates of the absolute magnitude of gs are somewhat subjective, depending on the skill of the experimenter at selecting evenly exposed leaves, relative treatment differences in conductance are sensitively detected by different experimenters.

Mucilages and polysaccharides in Ziziphus species (Rhamnaceae): localization, composition and physiological roles during drought-stress.

The drought-tolerant tree species Ziziphus mauritiana Lamk. and Z. rotundifolia Lamk. were shown to have similar high mucilage concentrations (7-10% dry weight) in their leaves, with large numbers of mucilage-containing cells in the upper epidermis and extracellular mucilage-containing cavities in the leaf veins and stem cortex. The main sugar constituents of the water-soluble mucilage extract were rhamnose, glucose and galactose. During drought-stress in two independent studies, foliar mucilage content was unaffected in both species, but glucose and starch contents declined significantly in crude mucilage extracts from droughted leaves. Enzymatic hydrolysis of the mucilage extract using alpha-amylase and amyloglucosidase released glucose, indicating that a mucilage-associated water-soluble glucan, with alpha-1,4- and alpha-1,6-linkages, may exist which was extracted together with the mucilage. From the current data, it is not possible to localize the glucan to determine whether or not it is associated with mucilage-containing cells. Data from pressure-volume analyses of drought-stressed and control leaves showed that, in line with their similar mucilage contents, the relative leaf capacitance isotherm (change in relative water content per unit change in water potential) was similar in both species. During drought-stress, reduced relative capacitance resulted from osmotic adjustment and decreased wall elasticity. Data suggest that in Ziziphus leaves, intracellular mucilages play no part in buffering leaf water status during progressive drought. In Ziziphus species, growing in environments with erratic rainfall, the primary role of foliar mucilage and glucans, rather than as hydraulic capacitors, may be as sources for the remobilization of solutes for osmotic adjustment, thus enabling more effective water uptake and assimilate redistribution into roots and stems prior to defoliation as the drought-stress intensified.

Incidence of allergic reactions with fresh frozen plasma or cryo-supernatant plasma in the treatment of thrombotic thrombocytopenic purpura.

Plasma replacement for thrombotic thrombocytopenic purpura (TTP) is accomplished with various plasma products. This study sought to determine the incidence of allergic reactions with FFP or CPP as replacement in therapeutic plasma exchange (TPE). Forty-one TTP patients were identified retrospectively who received TPE replacement with either FFP (n=21) or CPP (n=20). Anti-histamine was administered prophylactically following the initial occurrence of an allergic reaction (urticaria, respiratory distress, or anaphylaxis with hypotension). Fifty-one allergic reactions occurred in 65.8% of patients. Urticaria comprised 49 of 51 (96%) of reactions and respiratory distress the remaining 4%. No anaphylaxis occurred. Nineteen urticarial reactions occurred in 50% of CPP recipients compared to 71% of FFP recipients (P=0.28). Anti-histamine breakthrough occurred in 36.3% of patients who experienced a previous allergic reaction with CPP and 37.5% with FFP (P=1.0). The overall risk of allergy per unit of plasma was 1.37% (1.23 % CPP, 1.48% FFP), comparable to estimates in non-TTP recipients. The median number of donor exposures preceding the first allergic reaction was 35 and 32, CPP and FFP, respectively (P=0.63). The mean volume of plasma transfused prior to reaction was 9,883 mL for CPP and 9,348 mL for FFP (P=0.85). Neither product was advantageous in preventing allergic complications. Because of the large volume, the number of donor exposures, and prolonged duration of therapy, allergic reactions to plasma are common (65.8%) in the treatment of TTP.