Rational design and synthesis of novel triazole- and tetrazole-fused iminosugars as potential inhibitors of amyotrophic lateral sclerosis (ALS) linked SOD1 aggregation

In this manuscript we report the first example of an iminosugar that inhibits superoxide dismutase fibrillation associated with the amyotrophic lateral sclerosis (ALS). The present work involves synthesis of novel triazole and tetrazole embedded iminosugars, synthesized in 11-13 high yielding steps starting from readily available tri-O-benzyl-D-glucal and proceeding through a concomitant azidation - thermal intramolecular [3 + 2] cycloaddition reaction as the key step. One of these pre-designed iminosugars was found to inhibit fibrillation of SOD1 and also has shown propensity to break pre-formed fibrils. Docking and MD simulation studies suggest that the most probable interaction of this compound is a hydrogen bonding with Arg69, a loop IV residue of SOD1, which has a crucial role in stabilizing the native conformation of SOD1.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Kinetics theories to understand the mechanism of aggregation of a protein and to design strategies for its inhibition

Protein aggregation phenomenon is closely related to the formation of amyloids which results in many neurodegenerative diseases like Alzheimer's, Parkinson's, Huntington's, and Amyotrophic Lateral Sclerosis. In order to prevent and treat these diseases, a clear understanding of the mechanism of misfolding and self-assembly of peptides and proteins is very crucial. The aggregation of a protein may involve various microscopic events. Multiple simulations utilizing the solutions of the master equation have given a better understanding of the kinetic profiles involved in the presence and absence of a particular microscopic event. This review focuses on understanding the contribution of these molecular events to protein aggregation based on the analysis of kinetic profiles of aggregation. We also discuss the effect of inhibitors, which target various species of aggregation pathways, on the kinetic profile of protein aggregation. At the end of this review, some strategies for the inhibition of aggregation that can be utilized by combining the chemical kinetics approach with thermodynamics are proposed.

Quercetin and Baicalein Act as Potent Antiamyloidogenic and Fibril Destabilizing Agents for SOD1 Fibrils

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that has been associated with the deposition of aggregates of superoxide dismutase 1 (SOD1). Effective therapeutics against SOD1 fibrillation is still an area of active research. Herein, we demonstrate the potential of two naturally occurring flavonoids (quercetin and baicalein) to inhibit fibrillation of wild-type SOD1 with the aid of a series of biophysical techniques. Our seeding experiments reveal that both of these flavonoids significantly affect the fibril elongation. Interestingly, our ThT binding assay, TEM, and SDS-PAGE experiments suggest that these flavonoids also disintegrate the fibrils into shorter fragments but do not completely depolymerize them into monomers. Binding parameters obtained from the analysis of UV-vis spectra suggest that these flavonoids bind moderately to native SOD1 dimer and have different binding sites. Docking of these flavonoids with a non-native monomer, non-native trimer, and oligomer derived from the 11-residue segment of SOD1 indicates that both quercetin and baicalein can bind to these species and thus can arrest the elongation of fibrils by blocking the fibrillar core regions on the intermediate species formed during aggregation of SOD1. MTT assay data revealed that both the flavonoids reduced the cytotoxicity of SOD1 fibrils. Experimental data also show the antiamyloidogenic potential of both flavonoids against A4V SOD1 mutant fibrillation. Thus, our findings may provide a direction for designing effective therapeutic agents against ALS which can act as promising antiamyloidogenic and fibril destabilizing agents.

Use of an automated knot fastener shortens operative times in minimally invasive mitral valve repair

INTRODUCTION

Longer durations of cardiopulmonary bypass and aortic cross clamp are associated with increased morbidity and mortality. Little is known about the effect of automated knot fasteners (Cor-Knot®) in minimally invasive mitral valve repair on operative times and outcomes. The aim of this study was to evaluate whether these devices shortened cardiopulmonary bypass and aortic cross clamp times and whether this impacted on postoperative outcomes.

MATERIALS AND METHODS

All patients undergoing isolated minimally invasive mitral valve repair by a single surgeon between March 2011 and March 2016 were included (n = 108). Two cohorts were created based on the use (n = 52) or non-use (n = 56) of an automated knot fastener. Data concerning intraoperative variables and postoperative outcomes were collected and compared.

RESULTS

Preoperative demographics were well matched between groups with no significant difference in logistic Euroscore (manual vs automated: median 3.1, interquartile range, IQR, 2.1-5.5, vs 5.4, IQR 2.2-8.3; P = 0.07, respectively). Comparing manually tied knots to an automated fastener, cardiopulmonary bypass and aortic cross clamp times were significantly shorter in the automated group (cardiopulmonary bypass: median 200 minutes, IQR 180-227, vs 165 minutes (IQR 145-189 minutes), P < 0.001; aortic cross clamp 134 minutes (IQR 121-150 minutes) vs 111 minutes (IQR 91-137 minutes), P < 0.001, respectively). There was no mortality and no strokes, nor were there any differences in postoperative outcomes including reoperation for bleeding, renal failure, intensive care or hospital stay.

CONCLUSIONS

The use of an automated knot fastener significantly reduces cardiopulmonary bypass and aortic cross clamp times in minimally invasive mitral valve repair but this does not translate into an improved clinical outcome.

Interventions for improving modifiable risk factor control in the secondary prevention of stroke

BACKGROUND

People with stroke or transient ischaemic attack (TIA) are at increased risk of future stroke and other cardiovascular events. Stroke services need to be configured to maximise the adoption of evidence-based strategies for secondary stroke prevention. Smoking-related interventions were examined in a separate review so were not considered in this review. This is an update of our 2014 review.

OBJECTIVES

To assess the effects of stroke service interventions for implementing secondary stroke prevention strategies on modifiable risk factor control, including patient adherence to prescribed medications, and the occurrence of secondary cardiovascular events.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (April 2017), the Cochrane Effective Practice and Organisation of Care Group Trials Register (April 2017), CENTRAL (the Cochrane Library 2017, issue 3), MEDLINE (1950 to April 2017), Embase (1981 to April 2017) and 10 additional databases including clinical trials registers. We located further studies by searching reference lists of articles and contacting authors of included studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that evaluated the effects of organisational or educational and behavioural interventions (compared with usual care) on modifiable risk factor control for secondary stroke prevention.

DATA COLLECTION AND ANALYSIS

Four review authors selected studies for inclusion and independently extracted data. The quality of the evidence as 'high', 'moderate', 'low' or 'very low' according to the GRADE approach (GRADEpro GDT).Three review authors assessed the risk of bias for the included studies. We sought missing data from trialists.The results are presented in 'Summary of findings' tables.

MAIN RESULTS

The updated review included 16 new studies involving 25,819 participants, resulting in a total of 42 studies including 33,840 participants. We used the Cochrane risk of bias tool and assessed three studies at high risk of bias; the remainder were considered to have a low risk of bias. We included 26 studies that predominantly evaluated organisational interventions and 16 that evaluated educational and behavioural interventions for participants. We pooled results where appropriate, although some clinical and methodological heterogeneity was present.Educational and behavioural interventions showed no clear differences on any of the review outcomes, which include mean systolic and diastolic blood pressure, mean body mass index, achievement of HbA1c target, lipid profile, mean HbA1c level, medication adherence, or recurrent cardiovascular events. There was moderate-quality evidence that organisational interventions resulted in improved blood pressure control, in particular an improvement in achieving target blood pressure (odds ratio (OR) 1.44, 95% confidence interval (CI) 1.09 to1.90; 13 studies; 23,631 participants). However, there were no significant changes in mean systolic blood pressure (mean difference (MD), -1.58 mmHg 95% CI -4.66 to 1.51; 16 studies; 17,490 participants) and mean diastolic blood pressure (MD -0.91 mmHg 95% CI -2.75 to 0.93; 14 studies; 17,178 participants). There were no significant changes in the remaining review outcomes.

AUTHORS' CONCLUSIONS

We found that organisational interventions may be associated with an improvement in achieving blood pressure target but we did not find any clear evidence that these interventions improve other modifiable risk factors (lipid profile, HbA1c, medication adherence) or reduce the incidence of recurrent cardiovascular events. Interventions, including patient education alone, did not lead to improvements in modifiable risk factor control or the prevention of recurrent cardiovascular events.

Levels of detection of hypertension in primary medical care and interventions to improve detection: a systematic review of the evidence since 2000

OBJECTIVES

In England, many hypertensives are not detected by primary medical care. Higher detection is associated with lower premature mortality. We aimed to summarise recent evidence on detection and interventions to improve detection in order to inform policies to improve care.

DESIGN

Data sources: systematic review of articles published since 2000. Searches of Medline and Embase were undertaken. Eligibility criteria: published in English, any study design, the setting was general practice and studies included patients aged 18 or over.

EXCLUSION CRITERIA

screening schemes, studies in primary care settings other than general practice, discussion or comment pieces.

PARTICIPANTS

adult patients of primary medical care services.

SYNTHESIS

study heterogeneity precluded a statistical synthesis, and papers were described in summary tables.

RESULTS

Seventeen quantitative and one qualitative studies were included. Detection rates varied by gender and ethnic group, but longitudinal studies indicated an improvement in detection over time. Patient socioeconomic factors did not influence detection, but living alone was associated with lower detection. Few health system factors were associated with detection, but in two studies higher numbers of general practitioners per 1000 population were associated with higher detection. Three studies investigated interventions to improve detection, but none showed evidence of effectiveness.

LIMITATIONS

The search was limited to studies published from 2000, in English. There were few studies of interventions to improve detection, and a meta-analysis was not possible.

CONCLUSIONS AND IMPLICATIONS

Levels of detection of hypertension by general practices may be improving, but large numbers of people with hypertension remain undetected. Improvement in detection is therefore required, but guidance for primary medical care is not provided by the few studies of interventions included in this review. Primary care teams should continue to use low-cost, practical approaches to detecting hypertension until evidence from new studies of interventions to improve detection is available.

The analgesic efficacy of continuous transversus abdominis plane block in renal transplant recipients

Background and Aims:

Transversus abdominis plane (TAP) block is suitable for operations where parietal pain is a major cause of pain. Renal transplant recipients are ideally suited to gain maximum benefit from TAP block as the incision classically involves the lower abdomen. This study was conducted to evaluate the analgesic efficacy of continuous TAP block in transplant recipients.

Material and Methods:

In a prospective double-blind study, 40 chronic renal failure patients undergoing open renal transplant were randomly divided into two groups. At the end of surgery during closure, a multiorifice epidural catheter was placed in TAP plane. Study group (Group S) received Inj bupivacaine bolus 1 mg/kg (0.25%) followed by infusion 0.25 mg/kg (0.125%) through the catheter, whereas control group (Group C) received normal saline through the catheter. Inj pentazocine (0.3 mg/kg) was given as rescue analgesic at visual analogue score (VAS) > 3 in any group at rest or on movement. The analgesic efficacy was judged by VAS, time of first rescue analgesic, and total analgesic consumption in 24 h.

Results:

Patients in Group S had significant lower VAS scores, longer time to first rescue analgesic (270 ± 347.96 vs. 42.85 ± 32.27 min) and lower pentazocine consumption (9.75 ± 13.95 vs. 56.42 ± 12.46 mg) in 24 h. There was significant sedation in Group C.

Conclusion:

The TAP catheter technique for postoperative pain control after renal transplant has proved to be effective in relieving the postoperative pain after renal transplant with less pentazocine requirement and less sedation.

"A short trauma course for physicians in a resource-limited setting: Is low-cost simulation effective?"

INTRODUCTION

Morbidity and mortality from intentional and unintentional injury accounts for a high burden of disease in low- and middle-income countries. In addition to prevention measures, interventions that increase healthcare capacity to manage injuries may be an effective way to decrease morbidity and mortality. A trauma curriculum tailored to low-resource settings was implemented in Managua, Nicaragua utilising traditional didactic methods and novel low-cost simulation methods. Knowledge gain in attending and senior residents was subsequently assessed by using pre- and post-written tests, and by scoring pre- and post-simulation scenarios.

MATERIALS AND METHODS

A 5-day trauma course was designed for Nicaraguan attending and senior resident physicians who practice at six hospitals in Managua, Nicaragua. On days 1 and 5, participants underwent pre- and post-training evaluations consisting of a 26-question written exam and 2 simulation cases. The written exam questions and simulations were randomly assigned so that no questions or cases were repeated. The Wilcoxon signed-rank test was used to compare pre- and post-training differences in the written exam, and the percentage of critical actions completed in simulations. Time to critical actions was also analyzed using descriptive statistics.

RESULTS

A total of 33 participants attended the course, including 18 (55%) attending and 15 (45%) resident physicians, with a 97% completion rate. After the course, overall written examination scores improved 26.3% with positive mean increase of 15.4% (p<0.001). Overall, simulation scores based on the number of critical actions completed improved by 91.4% with a positive mean increase of 33.67 (p<0.001). The time to critical action for completion of the primary survey and cervical spine immobilisation was reduced by 55.9% and 46.6% respectively.

CONCLUSIONS

A considerable improvement in participants' knowledge of trauma concepts was demonstrated by statistically significant differences in both pre- and post-course written assessments and simulation exercises. The participants showed greatest improvement in trauma simulation scenarios, in which they learned, and subsequently demonstrated, a standardised approach to assessing and managing trauma patients. Low-cost simulation can be a valuable and effective education tool in low- and middle-income countries.

Laparoscopic Transplantation Following Transvaginal Insertion of the Kidney: Description of Technique and Outcome

Laparoscopic kidney transplantation (LKT) is well accepted modality of treatment for ESRD patients at our center. Usually, the kidney is inserted through small Pfannenstiel incision. With the permission of the Internal Review Board, we carried out LKT in eight female recipients following insertion of the kidney through the vagina. The kidney was procured by the retroperitoneoscopic approach. Antibiotic prophylaxis was given. All cases were carried out successfully with immediate graft function and 100% graft and patient survival at 1 year of follow-up. Estimated glomerular filtration rate at 1 month and 1 year was similar to eight randomly selected female recipients who underwent open kidney transplantation (OKT). No analgesia was required in seven out of eight patients after the 3rd postoperative day. In summary, vaginal insertion of kidney and LKT is safe and feasible in a selected group of patients. It is associated with better analgesia and has similar allograft function as compare to OKT.

First Report of Diplodia seriata Causing Pear Branch Canker Dieback in California

California produces 26% of the United States pear crop on approximately 5,600 ha. A survey of seven northern California pear orchards (Pyrus communis cv. Bartlett) in summer 2010 revealed the presence of wedge-shaped cankers on 2- to 5-cm diameter branches, equating to 1- to 3-year-old wood. Many of the observed cankers occurred near pruning wounds, and there was decreased foliation on infected branches. Infected wood was surface disinfected with 95% ethanol and briefly flamed. After removing bark, small sections of diseased tissue were plated onto 4% potato dextrose agar (PDA) amended with 0.01% tetracycline and placed on the lab bench at 22°C until fungal growth emerged. Fungal colonies that were consistently isolated were transferred to fresh PDA using hyphal tip isolation. Fungal colonies were dark brown to gray with aerial mycelium and formed pycnidia after 15 days of incubation at 22°C. Conidia were brown, oval to oblong, and measured (16.5-) 20 to 24 (-26) × (7.5) 8.75 to 11 (-12.5) μm (n = 50). DNA from 14- to 21-day-old colonies was extracted and sequences of the rDNA internal transcribed spacer region and part of the β-tubulin gene were amplified using primers ITS4/ITS5 and Bt2a/Bt2b, respectively (2). The DNA sequences of fungal isolates from California showed 99 to 100% homology with the ex-type Diplodia seriata De Not. (1) CBS112555 deposited in GenBank. DNA sequences from three California isolates were submitted to GenBank with accession numbers KC937062, KC937065, KF481957, KF481598, KF481959, and KF481960. Pathogenicity tests were performed in March 2011 on 3-year-old Bartlett pear trees planted at an experimental farm in Davis, CA. A single, circular, 2-cm pruning wound at the top of the trunk was inoculated on each of three single-tree replications using 2-cm mycelial plugs from 14-day-old colonies growing on PDA. After inoculation, mycelial plugs were covered and sealed with Parafilm and aluminum foil for the duration of the trial. Three control trees were inoculated using sterile PDA plugs. Twelve months after inoculation, UCD103 and UCD105 were consistently re-isolated from the margin between necrotic and healthy tissue using the same methods described for the original isolation, and UCD102 was re-isolated in two out of three plants. The average lesion lengths of UCD102, UCD103, UCD105, and control plants were 12.5, 17.3, 23, and 1 mm, respectively. Control lesions were short and sterile, and seemed to be a physiological reaction from the plant. A second pathogenicity test was completed in 5 months beginning in June 2012. UCD105 was consistently re-isolated, and UCD102 and UCD103 were re-isolated in two out of three plants. The average lesion lengths for UCD102, UCD103, UCD105, and control plants were 2, 3, 5, and 1 mm, respectively. Compared to grapevine (Vitis vinifera), the pathogen grows more slowly in pear tissue under natural conditions. To our knowledge, this is the first report describing D. seriata as a causal agent of pear branch canker in California. Canker diseases can reduce the lifespan of perennial plants, ultimately leading to long term economic losses for growers (3). References: (1) A. J. L. Phillips et al. Fungal Diversity 25:141, 2007. (2) J. R. Urbez-Torres et al. Plant Dis. 90:1490, 2006. (3) J. R. Urbez-Torres and W. D. Gubler. Plant Dis. 93:584, 2009.

Laparoscopic kidney transplantation: an initial experience

Laparoscopic donor nephrectomy has the advantages of less pain, early ambulation and shorter hospitalization compared to open donor nephrectomy. Kidney recipient surgery is, however, traditionally performed by open surgery. Our aim was to study feasibility and safety of laparoscopic kidney transplantation (LKT). After permission from Internal Review Board, LKT was performed in four patients. All kidneys were procured from deceased donors. Left kidney was used for LKT and transplanted in left iliac fossa while right kidney was used for standard open kidney transplantation (OKT). All transplantation procedures were performed successfully. Cold ischemia time varied between 4 h and 14 h. For LKT, mean time for anastomosis was 65 (range 62-72) min, mean operative time was 3.97 (range 3.5-5) h, mean blood loss was 131.25 mL (range 45-350) mL. Mean wound length was 7 cm in LKT group and 18.4 cm in OKT group. Delayed graft function was observed in one patient in each group. One patient was lost in OKT group due to posttransplant bacterial meningitis. At 6 months, both groups have comparable value of serum creatinine. In conclusion, LKT is technically feasible and safe. Long term outcome needs to be evaluated in a larger study.

Successful en bloc transplantation of pediatric deceased donor kidneys with grade 1 injury

Kidney transplantation from deceased donors is in its infancy in India. Marginal donors are now accepted by many centers for kidney transplantation. We report a case of procurement of en bloc kidneys from a pediatric deceased donor having grade 1 renal injury and transplanted to an adult recipient with a follow up of two years and five months.

Novel topical BoNTA (CosmeTox, toxin type A) cream used to treat hyperfunctional wrinkles of the face, mouth, and neck

BACKGROUND

This study aimed to compare the effect of the stabilized novel topical botulinum neurotoxin type A (BoNTA) cream (CosmeTox) and a placebo cream on subjects, to compare clinician-reported outcomes, and to assess the safety and utility of the novel topical BoNTA cream for treating the entire upper face, chin, and neck areas.

METHODS

This study randomized 40 female subjects to receive either topical BoNTA (CosmeTox) cream (2 U/ml) or an identical placebo cream (without BoNTA) on the face, chin, and neck areas. The subjects were followed for 12 weeks. The main outcome measures were the Facial Line Outcomes questionnaire scores and results from the Self-Perception of Age instrument, which assesses age of appearance relative to actual age.

RESULTS

The BoNTA topical cream (CosmeTox) treatment produced significant improvements in the Facial Lines Outcome scores, which were maintained throughout the study period and lasted more than 3 months. The BoNTA topical cream treatment also reduced the age of appearance for a majority of subjects. The placebo had no effect on any measure. No serious adverse events occurred during the entire study period.

CONCLUSION

Topical treatment with the stabilized BoNTA cream (CosmeTox) to the entire upper facial lines resulted in significantly improved facial features and age appearance, as measured by the subjects and clinicians. The BoNTA cream (CosmeTox) resulted in a significantly younger, more satisfying, relaxed appearance.

Management of Calculi in A Donor Kidney

INTRODUCTION

We evaluated the safety and efficacy of ex vivo ureteroscopy (ExURS) and extracorporeal shock wave lithotripsy (ESWL) as means of rendering a donated kidney stone-free in living related and deceased donor renal transplantation.

MATERIAL AND METHODS

Three cases with calculi in donor kidneys were managed; 1 was from a living related donor and 2 were from deceased donors. Immediately after cold perfusion, ExURS was performed with iced saline solution in 2 cases. Access to the collecting system was via the ureteral stump. Calculi were fragmented with pneumatic intracorporeal lithotripsy and fragments were removed with forceps. Posttransplantation ESWL was given to 1 patient for migration of a small lower caliceal calculus in the upper ureter in 1 allograft of a dual-kidney transplantation.

RESULTS

Access to the renal collecting system and stone fragmentation was technically successful in both cases. Indwelling ureteral stents were kept during transplantation in all cases. There were no intraoperative or postoperative ureteral complications. Following ESWL, stone was fragmented and cleared on its own within a week. At mean follow up of 2.2 years no new stone formed in any recipient or donor.

CONCLUSIONS

ExURS was technically feasible to render a stone-bearing kidney stone- free without compromising ureteral integrity or renal allograft function. ESWL could be performed at a later date.

An investigation into the current peri-operative nutritional management of oesophageal carcinoma patients in major carcinoma centres in England

INTRODUCTION

Patients with oesophageal carcinoma are at high risk of malnutrition. The aim of this study was to assess current practice for the nutritional management of patients following surgery for oesophageal carcinoma.

PATIENTS AND METHODS

A postal questionnaire was sent to 82 dietetic departments of those hospitals in England identified as major centres for upper gastrointestinal surgery.

RESULTS

Of the 66 (80%) responses received, 22 (33%) centres routinely perform pre-operative nutritional screening/assessment on oesophageal carcinoma patients. Centres with dietetic support dedicated to these patients are more likely to perform a pre-operative nutritional assessment (n = 17; 55%) than those without (n = 5; 14%; P < 0.001; chi(2) = 12.17). Pre-operative nutritional support is routinely provided in only 11 (17%) centres with the majority of centres (n = 50; 75%), providing it if patients are considered malnourished only. A total of 47 (70%) centres routinely provide postoperative nutritional support with jejunal feeding being the most commonly chosen route. Dedicated dietetic support is provided at 31 (47%) centres. Those centres with a dedicated dietitian are more likely to provide early postoperative nutritional support (n = 27; 87%) than those without (n = 20; 57%; P = 0.007; chi(2) = 7.195) and more likely to review patients routinely following discharge from hospital (n = 25 [81%] with a dietitian versus n = 17 [49%] without; P = 0.007; chi(2) = 7.2).

CONCLUSIONS

The nutritional management of patients following surgery for upper gastrointestinal carcinoma is not uniform with practice varying considerably between centres. Those centres with a dedicated dietitian are more likely to assess patients' nutritional status and provide nutritional support.

Thiazolidinediones in type 2 diabetes--have they lived up to expectations?

The thiazolidinediones have been in clinical use for the management of type 2 diabetes for the past five years. These agents reduce insulin resistance by acting as ligands that regulate gene expression related to the proliferation and differentiation of adipose tissue. Overall, data from several clinical studies suggest that their hypoglycaemic efficacy is slightly less than sulphonylureas and metformin but greater than acarbose and the glinides. In the short term, treatment with thiazolidinediones is associated with weight gain, expansion of plasma volume, fluid retention, peripheral oedema, an increased risk of congestive heart failure when combined with insulin, and an idiosyncratic hepatotoxic reaction to troglitazone. The long term consequences of these effects are not known. Contrary to expectations, despite being insulin sensitisers these agents do not favourably influence the other components of the metabolic syndrome that are believed to be aggravated by insulin resistance. Dyslipidaemia and elevated blood pressure, which are major risk factors of cardiovascular disease in type 2 diabetes, are not favourably improved with thiazolidinedione treatment. Unlike the sulphonylureas and metformin, which have been shown in recent long term randomised studies to reduce cardiovascular risk substantially, there is no data on the long term cardiovascular safety of the thiazolidinediones. At present, in the absence of long term data, the thiazolidinediones in clinical use are moderately effective hypoglycaemic drugs with no particular advantage over existing treatments in type 2 diabetes.

Myocardial metabolic changes during pediatric cardiac surgery: a randomized study of 3 cardioplegic techniques

BACKGROUND

Blood cardioplegia and terminal warm blood cardioplegic reperfusion ("hot shot") reduce myocardial injury and improve metabolic recovery in hypoxic but not normoxic experimental models. However, there is little evidence of a benefit of either technique in pediatric clinical practice compared with crystalloid cardioplegia.

METHODS

Pediatric patients undergoing cardiac surgery were randomized to receive intermittent antegrade cold crystalloid cardioplegia, cold blood cardioplegia, or cold blood cardioplegia with a hot shot. Right ventricular biopsy specimens were collected before ischemia, at the end of ischemia, and 20 minutes after reperfusion. Cellular metabolites were analyzed. In acyanotic patients postoperative serum troponin I levels were also measured at 1, 4, 12, 24, and 48 hours.

RESULTS

Of 103 patients recruited, 32 (22 acyanotic and 10 cyanotic), 36 (24 acyanotic and 12 cyanotic), and 35 (25 acyanotic and 10 cyanotic), respectively, were allocated to the groups receiving cold crystalloid cardioplegia, cold blood cardioplegia, and cold blood cardioplegia with a hot shot. Cyanotic patients were younger, with longer crossclamp times. There were no significant differences in clinical outcomes between cardioplegic methods. The cardioplegic method had no overall effect in terms of adenosine triphosphate, ln(adenosine triphosphate/adenosine diphosphate), or ln(glutamate) in acyanotic patients (P =.11, P =.66, and P =.30, respectively). Also, there was no significant difference between groups in troponin I release. However, in cyanotic patients cold blood cardioplegia with a hot shot significantly reduced the decrease in adenosine triphosphate, ln(adenosine triphosphate/adenosine diphosphate), and glutamate observed at the end of ischemia and after reperfusion compared with the decrease seen in those receiving cold crystalloid cardioplegia (P =.002, P =.003, and P =.008, respectively), with cold blood cardioplegia representing an intermediate.

CONCLUSIONS

For cyanotic patients (younger, with longer crossclamp times), cold blood cardioplegia with a hot shot is the best method of myocardial protection. For acyanotic patients (older, with shorter crossclamp times), cardioplegic technique is not critical.

Myocardial taurine, development and vulnerability to ischemia

Depleting intracellular taurine in heart cells improves their resistance to ischemia and reperfusion injury. The aim of this work was to see whether physiologically low levels of endogenous taurine also reflect a reduced vulnerability of the myocardium to cardiac insults. The myocardial concentration of taurine was measured during different stages of development and compared with vulnerability to ischemia and reperfusion injury in the rat and in pediatric patients undergoing cardiac surgery.Rat hearts with relatively lower levels of taurine were significantly more resistant to an ischemic inult and there was a strong negative correlation between taurine content and recovery. Children's hearts had significantly lower taurine levels compared to infants' hearts which was consistent with their known increased resistance to an ischemic cardioplegic insult (Imura et al., 2001). This work shows that the changes in the concentration of myocardial taurine during development correlate with vulnerability to ischemia where low myocardial taurine is associated with improved recovery upon reperfusion.

Detection of postoperative pseudoaneurysms following abdominal aortic aneurysm repair in Behçet's disease by MRA

We report the development of two anastomotic pseudoaneurysms in a patient with Behçet's disease eighteen months after abdominal aortic aneurysm repair. Major asymptomatic vascular complications should be suspected in patients with Behçet's disease with a history of vascular surgery and treated expediently due to the risk of rupture. Magnetic resonance angiography, contrast-enhanced computed tomography or ultrasound scanning should be performed at least every 6 months after vascular surgery.

A 23-year review of the management of acute retention of urine: progressing or regressing?

A retrospective review of all patients in Oxford under the care of one consultant urologist (GJF) who presented on alternate years over a 23-year period with acute retention of urine was undertaken. Data were collected on the: (i) number of patients discharged from hospital with an in-dwelling catheter; (ii) duration of catheter drainage prior to surgery; and (iii) duration of postoperative stay. In all, 244 patients underwent prostatectomy. Over the 23-year period, there was a significant increase in the proportion of patients discharged prior to surgery (P < 0.001) as well as their median duration of catheterisation (P < 0.001): more than 50% were catheterised for more than 3 months in 1997. Conversely, post-operative hospital stay has decreased. Prolonged catheter drainage carries considerable morbidity, with 72% experiencing some complication. Most patients feel they lose dignity, 69% consider it uncomfortable and more than 50% complain of burning sensations, bladder spasms and a persistent desire to micturate. We recommend that patients should not be placed on routine waiting lists where they are liable to remain for an unacceptably long time. Targets should be set to admit them within a set period and theatre lists made available. We feel that six weeks is a realistic target.

Antimicrobial efficacy of two commercial RGP contact lens care systems

We compared the antimicrobial activities of two rigid gas permeable (RGP) lens care systems, a one-step wetting and soaking system (0.005% chlorhexidine gluconate, 0.02% EDTA) and a conditioning solution (0.006% chlorhexidine gluconate, 0.05% EDTA). The formulations were individually inoculated with approximately 10(6) CFU/mL of a pathogenic organism. Both the one-step wetting and soaking system and the conditioning solution demonstrated good antimicrobial efficacy against Pseudomonas aeruginosa, Staphylococcus epidermidis, Serratia marcescens, and Aspergillus fumigatus. However, the one-step wetting and soaking system provides better disinfection against Candida albicans (1.2 log reduction in 4 hours) than the conditioning solution (0.39 log reduction in 4 hours). The one-step system also reduced S. marcescens by 5 logs in 1 hour, whereas the conditioning solution reduced S. marcescens by about 2 logs only in the same time interval. Although both RGP lens care systems use the same active preservative (chlorhexidine digluconate), the variation in disinfecting activities may be attributed to differences in formulation and buffer systems.

Functional relationship between ammonia and gangliosides in brain

The functional significance of ammonia production in brain under physiological or pathological conditions is not clearly known. NH4+ stimulates Na+, K+ activated ATPase causing stabilization of neuronal membranes of which gangliosides are major structural components. Moreover ammonia is known to inhibit lysosomal enzymes which include enzymes degrading gangliosides. Gangliosides have been shown to stimulate neuritogenesis in neuronal cultures and prevent the damage of the neurons from glutamate toxicity particularly in areas of brain ischemia. Hyperammonemia without any behavioural changes was induced in experimental rats by intraperitoneal administration of either a single dose (0.8 mmol/100 g wt.) or by six 'hourly' doses (0.6 mmol/100 g wt.) of ammonium acetate. An increase in the content of gangliosides along with a rise in the content of GD1A and GD1B without any change in beta-galactosidase and N-acetylhexosaminidase was observed in cerebral cortex, cerebellum, and brain stem, following the administration of single dose of ammonium acetate. Gangliosides, after extraction from the different brain regions, were estimated by the thiobarbituric acid method and expressed in terms of sialic acid. Individual gangliosides were separated and estimated by thin layer chromatography using resorcinol as the staining agent. These results suggest that ammonia production in the neuronal pathways in brain either as a result of repeated stimulation under physiological conditions or as a result of focal ischemia or injury, may likewise cause an increase in the content of gangliosides which may help in neuritic growth (physiological conditions facilitating synaptic plasticity) and may exert a protective effect on the neurons in the ischemic area against glutamate toxicity.

Nerve growth factor increases calcium binding protein (calbindin-D28K) in rat olfactory bulb

Calbindin-D28K (CaBP28K) is a soluble intracellular protein capable of sequestering micromolar concentrations of calcium. The in vivo regulation of CaBP28K by recombinant human nerve growth factor (rhNGF) was studied in adult, male rats. Via Alzet 2002 pumps, each rat received, for 14 days, a lateral ventricle infusion (i.c.v.; n = 5-6/group) of 12 microliters PBS/day containing 1.0 microgram cytochrome C (control) or an equal amount of rhNGF. Six other animals received a vehicle or rhNGF infusion into the central neostriatum. CaBP28K was elevated by 75% (P less than 0.01) in the olfactory bulb following i.c.v. rhNGF in each of two experiments and was not altered in the temporal cortex, hippocampus, olfactory tubercle, cerebellum, or neostriatum. Direct striatal injections of rhNGF did not alter CaBP28K in the neostriatum or other regions (including the olfactory bulb). The increases in olfactory bulb CaBP28K protein levels were verified via Western blot analysis. CaBP28K immunocytochemistry revealed that 33% of olfactory bulb neurons are immunoreactive for CaBP28K and that the number or proportion of immunoreactive neurons did not change with i.c.v. infusions of rhNGF, suggesting that exogenously delivered rhNGF augments the content of CaBP28K in olfactory bulb neurons that normally express the protein. Endogenous NGF may function as a neuroprotective factor by enhancing the ability of these cells to sequester cytoplasmic calcium and retard calcium-mediated neurodegeneration.

Modern concepts of tonsillectomy

Tonsillectomy and adenoidectomy is still the most commonly performed surgical procedure in North America. The indications for surgery are constantly debated and seem to vary subjectively. The merits of performing a tonsillectomy for what is an essentially benign condition must be taken in perspective and require a more scientific approach. It is important to understand the pathophysiology of Waldeyer's ring and the changes brought about by recurring infections in the region. Treatment protocols vary, as do physician attitudes. Many tonsillectomies are still performed by surgeons other than otolaryngologists: for example, by family physicians and general surgeons. The authors discuss the indications and the scientific basic for tonsillectomy.

Chronic sinusitis

Paranasal sinuses, which communicate with the nasal passages through the sinus ostia, are essentially sterile structures, sterility being maintained by a healthy epithelium with normal actively beating cilia. Irritants, including viruses and bacteria, are trapped in mucus and cilia to allow the clearance of sinuses through the natural ostia into the nasal cavity. Interference with this normal physiological function results in inflammation and infection within the sinus cavities. All of the sinuses are subjected to the same environmental as well as physiological stimuli; thus it is uncommon for a single sinus to be infected and for the others to remain entirely normal. Allergic and non-allergic vasomotor rhinitis should be differentiated from chronic bacterial rhinosinusitis. The understanding of these diseases cannot be separated from the physiological function of the sinus mucosa.