Significance of predicted future liver remnant volume on liver failure risk after major hepatectomy: a case matched comparative study.

Introduction: Future liver remnant volume (FLRV), a risk factor for liver failure (PHLF) after major hepatectomy (MH), is not routinely measured. This study aimed to evaluate the association between FLRV and PHLF. Patients and methods: All patients undergoing MH (4 + segments) between 2011 and 2018 were identified from a prospectively maintained single-centre database. Perioperative data were collected for patients with PHLF, who were matched (1:2) with non-PHLF controls. FLRV and FLRV% (i.e., % of total liver volume) were calculated retrospectively from preoperative CT scans using Synapse-3D software, and compared between the PHLF and matched control groups. Results: Of 711 patients undergoing MH, PHLF occurred in 27 (3.8%), of whom 24 had preoperative CT scans available. These patients were matched to 48 non-PHLF controls, 98% of whom were classified as being at high risk of PHLF on preoperative risk scoring. FLRV% was significantly lower in the PHLF group, compared to matched controls (median: 28.7 vs. 35.2%, p = 0.010), with FLRV% < 30% in 58% and 29% of patients, respectively. Assessment of the ability of FLRV% to differentiate between PHLF and matched controls returned an area under the ROC curve of 0.69, and an optimal cut-off value of FLRV% < 31.5%, which yielded 79% sensitivity and 67% specificity. Conclusions: FLRV% is significantly predictive of PHLF after MH, with over half of patients with PHLF having FLRV% < 30%. In light of this, we propose that all patients should undergo risk stratification prior to MH, with the high risk patients additionally being assessed with CT volumetry.

Interventions to improve psychosocial well-being for children affected by HIV and AIDS: a systematic review.

In addition to its contribution to child mortality, HIV/AIDS has a substantial impact on the psychosocial well-being of children across the globe and particularly in sub-Saharan Africa. We conducted a systematic review of the literature in order to identify studies that assess the effectiveness of interventions developed to improve the psychosocial well-being of children affected by HIV/AIDS, published between January 2008 and February 2016. Studies that were eligible for the review included male and/or female children under the age of 18 years of age, who had lost a parent to HIV/AIDS, were living with a parent with HIV/AIDS, or were vulnerable because of other social and economic factors and living in communities of high HIV and AIDS prevalence, including child and caregiver reports. Studies were included if they documented any intervention to improve the psychosocial well-being of children including psychological therapy, psychosocial support and/or care, medical interventions and social interventions, with psychological and/or social factors as outcomes. We identified 17 interventions to improve the psychosocial well-being of children affected by HIV/AIDS. Of these, 16 studies took place in eight different low and middle-income countries (LMIC), of which 6 were in southern and eastern Africa. One study took place in a high-income setting. Of the total, fifteen showed some significant benefits of the intervention, while two showed no difference to psychosocial outcomes as a result of the intervention. The content of interventions, dosage and length of follow up varied substantially between studies. There were few studies on children under seven years and several focused mostly on girls. Efforts to improve evaluation of interventions to improve the psychosocial well-being of children affected by HIV/AIDS have resulted in a number of new studies which met the inclusion criteria for the review. Most studies are specially designed research projects and not evaluations of existing services. We call for increased partnerships between policy-makers, practitioners and researchers in order to design evaluation studies and can feed into the growing evidence base.

Ten Year Experience of Radioiodine Dosimetry: is it Useful in the Management of Metastatic Differentiated Thyroid Cancer?

AIMS: When a fixed activity of radioiodine is given for differentiated thyroid cancer (DTC), absorbed doses of radioiodine can vary widely and are not usually measured. Leeds Cancer Centre has routinely used a form of lesion-specific dosimetry for radioiodine patients. This study investigated if the results of dosimetry influenced treatment decisions for patients with advanced DTC. MATERIALS AND METHODS: Since 2005, patients with regionally advanced/metastatic DTC, who underwent radioiodine treatment together with dosimetry, were included in this study. Patients were excluded if their radioiodine post-treatment scan showed no abnormal uptake. Dosimetry was calculated using images taken 2, 3 and 7 days post-radioiodine. Regions of interest were drawn around lesions that required dosimetry and a time-dose activity curve was created. The total cumulative activity was equal to the area under the curve. Each patient's results were prospectively assessed by their oncologist regarding the usefulness of dosimetry in making management decisions. RESULTS: Thirty patients were studied and underwent 102 admissions of radioiodine between them. Dosimetry was carried out during 83 of 102 admissions. An absorbed dose of >20 Gy was taken as significant from dosimetry calculations, following which further radioiodine was considered. In 80% of patients, dosimetry was found to be useful when making treatment decisions. Only on 1/19 admissions did dosimetry calculate a minimum dose above 20 Gy in patients who had a total of four or more admissions for radioiodine. Ten per cent (3/30) had a complete response to radioiodine, both biochemically and radiologically, with a median follow-up of 6.7 months. Thirty-three per cent had a partial response/stable disease to radioiodine. The remainder had progressive disease. The decision to discontinue radioiodine therapy was often based on dosimetry and thyroglobulin results. Dosimetry was very useful for patients with thyroglobulin antibodies. CONCLUSION: Only 10% had a complete response. Therefore, a significant number of patients became refractory to radioiodine during a course of repeat admissions for treatment. Dosimetry (often together with thyroglobulin and anatomical scans) helped to identify these patients to avoid further futile radioiodine therapy.

Hemorrhagic Herpes Simplex Virus Type 1 Nephritis: An Unusual Cause of Acute Allograft Dysfunction.

Interstitial nephritis due to viruses is well-described after solid organ transplantation. Viruses implicated include cytomegalovirus; BK polyomavirus; Epstein-Barr virus; and, less commonly, adenovirus. We describe a rare case of hemorrhagic allograft nephritis due to herpes simplex virus type 1 at 10 days after living donor kidney transplantation. The patient had a favorable outcome with intravenous acyclovir and reduction of immunosuppression.

Use of Modeling and Simulation in the Design and Conduct of Pediatric Clinical Trials and the Optimization of Individualized Dosing Regimens.

Mathematical models of drug action and disease progression can inform pediatric pharmacotherapy. In this tutorial, we explore the key issues that differentiate pediatric from adult pharmacokinetic (PK) / pharmacodynamic (PD) studies, describe methods to calculate the number of participants to be enrolled and the optimal times at which blood samples should be collected, and therapeutic drug monitoring methods for individualizing pharmacotherapy. The development of pediatric-specific drug dosing dashboards is also highlighted, with an emphasis on clinical-relevance and ease of use.

Outcome following Resection of Biliary Cystadenoma: A Single Centre Experience and Literature Review.

Background. Biliary cystadenomas (BCAs) are rare, benign, potentially malignant cystic lesions of the liver, accounting for less than 5% of cystic liver tumours. We report the outcome following resection of biliary cystadenoma from a single tertiary centre. Methods. Data of patients who had resection of BCA between January 1993 and July 2014 were obtained from liver surgical database. Patient demographics, clinicopathological characteristics, operative data, and postoperative outcome were analysed. Results. 29 patients had surgery for BCA. Male : female ratio was 1 : 28. Clinical presentation was abdominal pain (74%), jaundice (20%), abdominal mass (14%), and deranged liver function tests (3%). Cyst characteristics included septations (48%), wall thickening (31%), wall irregularity (38%), papillary projections (10%), and mural nodule (3%). Surgical procedures included atypical liver resection (52%), left hemihepatectomy (34%), right hemihepatectomy (10%), and left lateral segmentectomy (3%). Median length of stay was 7 (IQ 6.5-8.5) days. Two patients developed postoperative bile leak. No patients had malignancy on final histology. Median follow-up was 13 (IQ 6.5-15.7) years. One patient developed delayed biliary stricture and one died of cholangiocarcinoma 11 years later. Conclusion. Biliary cystadenomas can be resected safely with significantly low morbidity. Malignant transformation and recurrence are rare. Complete surgical resection provides a cure.

The effect of changes in the health care environment on rehabilitation research: a survey of rehabilitation physicians.

OBJECTIVE: To assess what effect organizational, funding, and system changes in the health care environment may have on rehabilitation research. DESIGN: National survey. SETTING: Academic and clinical research programs. PARTICIPANTS: A total of 138 physicians participated in the survey. INTERVENTION: Mailed instrument requesting information on demographics, research activities, and indicators of change. MAIN OUTCOME MEASURES: Percentage of respondents reporting specific perceptions on (1) how academic and research programs are affected by organizational changes, (2) availability of research funds, and (3) the overall impact that health care changes have on research; between-group comparisons on survey responses. RESULTS: Usable responses were obtained from 138 physicians (response rate, 42.5%). Responding physicians reported workplace changes that included organizational restructuring (32.6%), affiliation with managed care plans (24%), and staff decreases (45.9%). Over half (54.8%) indicated that facility changes had detracted from their abilities to conduct research. A third (34.8%) reported declines in numbers of inpatient beds, and 89.6% reported decreased length of stay (LOS). Decreased LOS was cited as detracting from ongoing research by 36.6% and as discouraging new research by 33.3% of respondents. Although not reflected in measures of scholarly productivity, 53.6% reported having less time to devote to scholarship and 48.5% reported decreased professional activities. Over two thirds (67.4%) of responding physicians indicated that health care system changes had a negative impact on current research, and 54.5% indicated that such changes made it less likely that they would pursue new research. CONCLUSION: Changes in the health care system have had a dampening effect on rehabilitation physicians' research pursuits.

Development and commercial use of Bollgard cotton in the USA--early promises versus today's reality.

Bollgard cotton is the trademark given to a number of varieties of cotton bio-engineered to produce an insecticidal protein from Bacillus thuringiensis (Bt). When produced by the modified cotton plants, this protein controls certain lepidopterous cotton insect pests. Commercially available since 1996, these cotton varieties are purchased under a license agreement in which the growers pay a fee and agree to abide by the terms, which include a 1-year license to use the technology and agreement to participate in an insect resistance management program. Today, Bollgard cotton is grown on more than one-third of all cotton acreage in the USA. This product has reduced cotton production costs and insecticide use by providing an effective alternative to chemical insecticides for the control of tobacco budworm, Heliothis virescens; cotton bollworm, Helicoverpa zea; and pink bollworm, Pectinophora gossypiella. The specificity and safety profile of the Bt protein produced in planta in cotton was maintained. It has retained its selectivity for lepidopterous insects and lacks the characteristics found in potential allergenic proteins. Fiber quality, the agronomic characteristics of the plant and seed composition remain unchanged. New cotton technology is being developed to provide improved insect control and a wider spectrum of activity. These future products could further reduce insecticide use in the production of cotton, while maintaining the high level of safety and reliability that has been demonstrated by five seasons of Bollgard cotton use.

Contribution of glutamate dehydrogenase to mitochondrial glutamate metabolism studied by (13)C and (31)P nuclear magnetic resonance.

The relative contribution of glutamate dehydrogenase (GDH) and the aminotransferase activity to mitochondrial glutamate metabolism was investigated in dilute suspensions of purified mitochondria from potato (Solanum tuberosum) tubers. Measurements of glutamate-dependent oxygen consumption by mitochondria in different metabolic states were complemented by novel in situ NMR assays of specific enzymes that metabolize glutamate. First, a new assay for aminotransferase activity, based on the exchange of deuterium between deuterated water and glutamate, provided a method for establishing the effectiveness of the aminotransferase inhibitor amino-oxyacetate in situ, and thus allowed the contribution of the aminotransferase activity to glutamate oxidation to be assessed unambiguously. Secondly, the activity of GDH in the mitochondria was monitored in a coupled assay in which glutamine synthetase was used to trap the ammonium released by the oxidative deamination of glutamate. Thirdly, the reversibility of the GDH reaction was investigated by monitoring the isotopic exchange between glutamate and [(15)N]ammonium. These novel approaches show that the oxidative deamination of glutamate can make a significant contribution to mitochondrial glutamate metabolism and that GDH can support the aminotransferases in funneling carbon from glutamate into the TCA cycle.

The effect of changes in the U.S. health care system on rehabilitation research: the results of a survey of rehabilitation health professionals.

To obtain empirical data on the impact of changes in the health care system on rehabilitation research, physicians, psychologists, nurses, physical therapists, and occupational therapists involved in such research were surveyed to determine: 1) how the changes had affected their research productivity; 2) whether their scholarly activities (e.g., publications) had been affected; and 3) whether working in an academic vs non-academic institution made a difference. There were 438 usable responses (38% response rate) to the survey, which was sent to members of national organizations. Although the results somewhat supported suggestions that changes in the system had had a dampening effect on research, they were ambiguous, failing to clearly demonstrate a negative impact of managed care. More rigorous study is needed to enable firm conclusions and the formulation of actions to address factors that may influence rehabilitation research.

Subcortical infarction resulting in acquired stuttering.

Stuttering is an uncommon presentation of acute stroke. Reported cases have often been associated with left sided cortical lesions, aphasia, and difficulties with other non-linguistic tests of rhythmic motor control. Three patients with subcortical lesions resulting in stuttering are discussed. In one patient the ability to perform time estimations with a computerised repetitive time estimation task was characterised. One patient had a pontine infarct with clinical evidence of cerebellar dysfunction. A second patient had a left basal ganglionic infarct and a disruption of timing estimation. A third patient had a left subcortical infarct and a mild aphasia. These findings expand the reported distribution of infarction that can result in acquired stuttering. Subcortical mechanisms of speech control and timing may contribute to the pathophysiology of acquired stuttering.

Patterns of protein synthesis and tolerance of anoxia in root tips of maize seedlings acclimated to a low-oxygen environment, and identification of proteins by mass spectrometry.

Tolerance of anoxia in maize root tips is greatly improved when seedlings are pretreated with 2 to 4 h of hypoxia. We describe the patterns of protein synthesis during hypoxic acclimation and anoxia. We quantified the incorporation of [(35)S]methionine into total protein and 262 individual proteins under different oxygen tensions. Proteins synthesized most rapidly under normoxic conditions continued to account for most of the proteins synthesized during hypoxic acclimation, while the production of a very few proteins was selectively enhanced. When acclimated root tips were placed under anoxia, protein synthesis was depressed and no "new" proteins were detected. We present evidence that protein synthesis during acclimation, but not during subsequent anoxia, is crucial for acclimation. The complex and quantitative changes in protein synthesis during acclimation necessitate identification of large numbers of individual proteins. We show that mass spectrometry can be effectively used to identify plant proteins arrayed by two-dimensional gel electrophoresis. Of the 48 protein spots analyzed, 46 were identified by matching to the protein database. We describe the expression of proteins involved in a wide range of cellular functions, including previously reported anaerobic proteins, and discuss their possible roles in adaptation of plants to low-oxygen stress.

NMR adventures in the metabolic labyrinth within plants.

The era of metabolic engineering has begun, but there is only limited knowledge about metabolic fluxes and how they are regulated in plants. Particular challenges are the non-linearities between enzyme abundances, metabolite concentrations and metabolic fluxes, and the existence of metabolic networks that provide multiple routes between many important metabolites. NMR offers the means to distinguish and quantitate the fluxes along different routes to key metabolites. NMR can therefore help us understand and resolve the apparent paradox of, on the one hand, great metabolic flexibility evident in the natural responses of plants and, on the other hand, the unpredictable changes in metabolism reported in genetically engineered plants.

Identification of a nucleic acid binding domain in eukaryotic initiation factor eIFiso4G from wheat.

Higher plants have two complexes that bind the m7G-cap structure of mRNA and mediate interactions between mRNA and ribosomal subunits, designated eIF4F and eIFiso4F. Both complexes contain a small subunit that binds the 5'-cap structure of mRNA, and a large subunit, eIF4G or eIFiso4G, that binds other translation factors and RNA. Sequence-specific proteases were used to cleave native cap-binding complexes into structural domains, which were purified by affinity chromatography. We show here that eIFiso4G contains a central protease-resistant domain that binds specifically to nucleic acids. This domain spans Gln170 to Glu443 and includes four of the six homology blocks shared by eIFiso4G and eIF4G. A slightly shorter overlapping sequence, from Gly202 to Lys445, had no nucleic acid binding activity, indicating that the N-terminal end of the nucleic acid binding site lies within Gln170 to Arg201. The binding of the central domain and native eIFiso4F to RNA homopolymers and double- and single-stranded DNAs was studied. Both molecules had highest affinity for poly(G) and recognized single- and double-stranded sequences.

Does salivary gland scintigraphy predict response to pilocarpine in patients with post-radiotherapy xerostomia?

This study was undertaken to determine whether standard salivary gland scintigraphy may be used for the objective assessment of salivary gland sialogogues, in particular oral pilocarpine, in the treatment of post-radiotherapy xerostomia. Nine patients, with xerostomia following radiotherapy to the head and neck region underwent salivary gland scintigraphy with technetium-99m pertechnetate (40 MBq) both before and following 1 month of oral pilocarpine (5 mg tds). For each scan, the percentage uptake in the first 14 min, the peak uptake, time to peak uptake and the percentage of activity excreted following lemon juice stimulation were calculated. The results were correlated with the subjective response as assessed by questionnaire and visual analogue scale. We found no correlation between subjective response and any of the four scan parameters analysed. We could not identify any parameter that predicted those patients who would respond to pilocarpine. In addition, only one parameter, the percentage of activity excreted following stimulation, correlated with previous dose of radiotherapy to the gland. In conclusion, in this study salivary gland scintigraphy did not appear to correlate with or predict response to oral pilocarpine. However, future studies might consider performing salivary gland scintigraphy prior to radiotherapy as well as at differing time points following the commencement of pilocarpine.

Homocysteine as a risk factor for ischemic stroke: an epidemiological story in evolution.

Homocysteine is a metabolite of methionine that may be remethylated by enzymes requiring folate and cobalamin (vitamin B12) to again form methionine or catabolized by the pyridoxine (vitamin B6) dependent enzyme, cystathionine beta synthase (CBS) to form cysteine (fig. 1) [1]. Homocysteine exists as a combination of various free and protein bound forms, but the total amount is what is usually measured and may be reported as homocyst(e)ine [2]. The biological plausibility that elevated homocysteine might lead to vascular disease noted in 1969 by McCully [3]. He reported that a child with abnormal cobalamin metabolism and hyperhomocysteinemia had arterial lesions similar to those seen in children with severe hyperhomocysteinemia from CBS deficiency. These findings led to the idea that moderate elevations in homocysteine, even those still within the so-called normal range, might also lead to vascular pathology through a variety of mechanisms including atherosclerosis and thrombosis [4].