Dihydropyrancarboxamides related to zanamivir: a new series of inhibitors of influenza virus sialidases. 2. Crystallographic and molecular modeling study of complexes of 4-amino-4H-pyran-6-carboxamides and sialidase from influenza virus types A and B

The first paper in this series (see previous article) described structure-activity studies of carboxamide analogues of zanamivir binding to influenza virus sialidase types A and B and showed that inhibitory activity of these compounds was much greater against influenza A enzyme. To understand the large differences in affinities, a number of protein-ligand complexes have been investigated using crystallography and molecular dynamics. The crystallographic studies show that the binding of ligands containing tertiary amide groups is accompanied by the formation of an intramolecular planar salt bridge between two amino acid residues in the active site of the enzyme. It is proposed that the unexpected strong binding of these inhibitors is a result of the burial of hydrophobic surface area and salt-bridge formation in an environment of low dielectric. In sialidase from type A virus, binding of the carboxamide moeity and salt-bridge formation have only a minor effect on the positions of the surrounding residues, whereas in type B enzyme, significant distortion of the protein is observed. The results suggest that the decreased affinity in enzyme from influenza B is directly correlated with the small changes that occur in the amino acid residue interactions accompanying ligand binding. Molecular dynamics calculations have shown that the tendency for salt-bridge formation is greater in influenza A sialidase than influenza B sialidase and that this tendency is a useful descriptor for the prediction of inhibitor potency.

VDAC is a conserved element of death pathways in plant and animal systems

Programmed cell death (PCD) is very much a part of plant life, although the underlying mechanisms are not so well understood as in animals. In animal cells, the voltage-dependent anion channel (VDAC), a major mitochondrial outer membrane transporter, plays an important role in apoptosis by participating in the release of intermembrane space proteins. To characterize plant PCD pathways by investigating the function of putative components in a mammalian apoptotic context, we have overexpressed a rice VDAC (osVDAC4) in the Jurkat T-cell line. Overexpression of osVDAC4 induces apoptosis, which can be blocked by Bcl-2 and the VDAC inhibitor DIDS. Modifying endogenous VDAC function by DIDS and hexokinase II (HxKII) in Jurkat cells inhibits mitochondria-mediated apoptotic pathways. Finally, we show that DIDS also abrogates heat-induced PCD in cucumber cotyledons. Our data suggest that VDAC is a conserved mitochondrial element of the death machinery in both plant and animal cells.

Sudden death among postoperative patients with tetralogy of Fallot: a follow-up study of 243 patients for an average of twelve years

Two hundred and forty-three patients were evaluated following total correction of tetralogy of Fallot with special emphasis on postoperative conduction disturbances and on the occurrence of sudden death. The average follow-up period was 12 years with a range of 6 1/2 to 16 1/2 years. Sudden death occurred in seven patients. Four deaths were among those with right bundle branch block pattern (RBBB) and three of the four had premature ventricular contractions (PVC) for more than one month postoperatively. PVCs were documented in ten of the 158 patients with RBBB; sudden death occurred in three (30%). Three of the ten (30%) patients with trifascicular block pattern (TB) died suddenly, while no deaths occurred in 24 patients with bifascicular block pattern (BB). Progression of RBBB to BB and TB occurred in 18 patients from one month to seven years postoperatively (58% of BB and 40% of TB). The risk of sudden death in patients with RBBB and PVCs following tetralogy repair is high and warrants consideration of suppressive therapy. TB also carries a high risk. The finding that RBBB may progress to BB or TB mandates long-term careful follow-up of all tetralogy patients with postoperative conduction disturbances.

The role of maternal affect mirroring on social expectancies in three-month-old infants

The role of maternal affect mirroring on the development of prosocial behaviors and social expectancies was assessed in forty-one 2- to 3-month-old infants. Prosocial behavior was characterized as infants' positive behavior and increased attention toward their mothers. Social expectancies were defined as infants' expectancy for affective sharing. Mothers and infants were observed twice, approximately 1 week apart. During Visit 1, mothers and infants were videotaped while interacting over television monitors for 3 min. During Visit 2, infants engaged in a live, 3-min interaction with their mothers over television monitors (live condition) and they also viewed a replay of their mothers' interaction from the preceding week (replay condition). The order of conditions was counterbalanced. Maternal affect mirroring was measured according to the level of attention maintenance, warm sensitivity, and social responsiveness displayed. A natural split was observed with 58% of the mothers ranking high and 42% ranking low on these affect mirroring measures (HAM and LAM, respectively). Infants in the HAM group ranked high on prosocial behaviors and social expectancy--they discriminated between live and replay, conditions with smiles, vocalizations, and gazes. Infants in the LAM group ranked low on these variables--they gazed longer during the live condition than during the replay condition, but only when the live condition was presented first; however, they did not smile or vocalize more. These findings indicate that there is a relation between affect mirroring and social expectancies in infants.

Cetyltrimethylammonium chloride as a surfactant buffer additive for reversed-polarity capillary electrophoresis-electrospray mass spectrometry

The rapid analysis of picomole quantities of various cationic molecules (laser dyes, tripeptides and larger bioactive peptides) has been achieved by on-line capillary electrophoresis-electrospray mass spectrometry (CE-ES-MS). Use of the cationic surfactant, cetyltrimethylammonium chloride (CTAC) in the CE buffer greatly facilitated the analyses. Under reversed-polarity conditions (negative potential at the source vial), CTAC induces electroosmotic flow towards the mass spectrometer, presumably due to the creation of a cationic layer on the inner surface of the fused-silica capillaries. CTAC diminishes analyte-capillary wall interactions, allowing efficient separations and symmetrical peak shapes. It may be used over a wide range of pH values without loss of electroosmotic flow. Added selectivity, provided by the surfactant properties of CTAC, played a critical role in resolving closely related tripeptides as well as larger (five to thirteen amino acid units) peptides. Above the critical micelle concentration of CTAC, interactions with the pseudostationary micellar phase increased selectivity even for ionic analytes.

Predictive value of benign percutaneous adrenal biopsies in oncology patients

PURPOSE

Percutaneous CT guided biopsy is accepted as a safe procedure for the diagnosis of indeterminate adrenal masses in oncologic patients. The purpose of this study was to evaluate the accuracy of a 'negative for tumour' adrenal biopsy in the oncologic patient population by assessing subsequent outcome including clinical course, size and imaging characteristics of the adrenal lesions on follow-up imaging studies and pathological findings at re-biopsy or following adrenal mass resection.

MATERIALS AND METHODS

Retrospective analysis of 225 oncological patients (FM, 128;87; age range 33-87 years, mean age 66 years) who had undergone CT guided biopsies of an adrenal mass over a 5-year period was performed. Those patients with a report consistent with 'negative for malignancy' were evaluated by reviewing the medical records for patient demographics, primary malignancy, histology of adrenal tumour, subsequent surgical interventions, repeat adrenal biopsy under image guidance, by open surgery or at autopsy, subsequent abdominal imaging in which the adrenal gland was imaged, and long-term outcome including hospital admissions, or death.

RESULTS

Of the 225 CT-guided adrenal biopsies performed, 41 (18%) were negative for neoplasm. The primary neoplasm in these 41 patients included lung cancer (n=32), breast (n=5), renal cell carcinoma (n=2), bladder (n=1), and prostate (n=1). The size of the adrenal lesions ranged from 2.8-5 cm. Of the 41 biopsies, which were negative for tumour; 10 were identified as adenomas and the rest showed benign adrenal cortical cells or hyperplasia on cytopathology and histopathology. Repeat biopsies were obtained in 13/41 (31%) patients; whereas 2/41 (5%) had their adrenal gland analyzed on post mortem examination. None of these 15 repeat evaluations yielded tumour.

CONCLUSION

In oncological patients, pathological analysis of tissue samples obtained by CT-guided percutaneous biopsy, suggesting benign aetiology, is reliable and predicts a benign course on long-term follow-up. A negative or benign pathology result for a CT guided percutaneous adrenal biopsy can be regarded as a true negative evaluation in oncological patients with no necessity to repeat the biopsy.

Secondary hyperparathyroidism, and not beta 2-microglobulin amyloid, as a cause of spontaneous tendon rupture in patients on chronic hemodialysis

Spontaneous bilateral rupture of the extensor mechanisms of the knees, without significant history of trauma, has been reported rarely, generally in association with chronic metabolic disorders, such as chronic renal failure and secondary hyperparathyroidism. We report spontaneous tendon rupture in two patients on chronic hemodialysis for 4 and 11 years, with documented severe secondary hyperparathyroidism. One patient had spontaneous bilateral rupture of his quadriceps and partial avulsion of the left triceps tendons. The other patient had spontaneous rupture of his right quadriceps tendon. Both patients had markedly elevated serum intact parathyroid hormone and moderately elevated serum beta 2-microglobulin levels. Pathologic examination revealed diffuse immunohistochemical staining for beta 2-microglobulin but negative Congo-red staining of the ruptured tendon specimens. These cases and the previous reports in the literature suggest that secondary hyperparathyroidism may play a role in the pathogenesis of this clinical entity.

Immunohistochemical assessment of the effect of chemical and mechanical stimuli on cAMP and prostaglandin E levels in human gingival fibroblasts in vitro

These were evaluated by: (1) a combined immunohistochemical-microphotometric procedure (IH) and (2) conventional radiometric assays. Human gingival fibroblasts were in the sixth passage, grown and maintained in Dulbecco minimal essential medium (DMEM) supplemented with 10 per cent horse serum. For chemical and hormonal stimuli, cells (2 x 10(4] were seeded on tissue-culture chamber/slides, and incubated with graded doses of either parathyroid hormone (PTH) or prostaglandin E2 (PGE2) for assessment of their adenosine-3',5'-monophosphate (cAMP) levels, and with indomethacin or colchicine for their effect on PGE levels. For mechanical stimuli, cells (1 x 10(6] were seeded on culture dishes with a flexible plastic membrane and stretched for 5, 30, 60 or 120 min by placing the membrane over a convex surface and weighting the dish cover. After freeze drying, cells were stained by an immunoperoxidase technique for either cAMP or PGE, using monoclonal antibodies. The staining intensity of fibroblasts was determined at 600 nm wavelength. Per cent light absorbance of 15 cells in each slide was measured and the results tested by analysis of variance. The gingival fibroblasts responded to the drugs and hormones in a dose- and time-related fashion. Stretching significantly increased their synthesis of PGE with concomitant increase in cAMP. The IH results were compared with the radiometric assays to confirm the validity of this technique; both assays were valid for describing the quantitative responses of these cells to the stimuli. In particular, the IH method could localize those intracellular sites which demonstrated chances in relative cAMP and PGE concentrations in response to hormonal stimuli.

Caspase-3 activation is an early event and initiates apoptotic damage in a human leukemia cell line

Many apoptotic pathways culminate in the activation of caspase cascades usually triggered by the apical caspases-8 or -9. We describe a paradigm where apoptosis is initiated by the effector caspase-3. Diethylmaleate (DEM)-induced apoptotic damage in Jurkat cells was blocked by the anti-apoptotic protein Bcl-2, whereas, a peptide inhibitor of caspase-3 but not caspase-9 blocked DEM-induced mitochondrial damage. Isogenic Jurkat cell lines deficient for caspase-8 or the adaptor FADD (Fas associated death domain) were not protected from DEM-induced apoptosis. Caspase-3 activation preceded that of caspase-9 and initial processing of caspase-3 was regulated independent of caspase-9 and Bcl-2. However, inhibitors of caspase-9 or caspase-6 regulated caspase-3 later in the pathway. We explored the mechanism by which caspase-3 processing is regulated in this system. DEM triggered a loss of Erk-1/2 phosphorylation and XIAP (X-linked inhibitor of apoptosis protein) expression. The phorbol ester PMA activated a MEK-dependent pathway to block caspase-3 processing and cell death. Constitutively active MEK-1 (CA-MEK) upregulated XIAP expression and exogenous XIAP inhibited DEM-induced apoptotic damage. Thus, we describe a pathway where caspase-3 functions to initiate apoptotic damage and caspase-9 and caspase-6 amplify the apoptotic cascade. Further, we show that MEK may regulate caspase-3 activation via the regulation of XIAP expression in these cells.

Sialidase inhibitors related to zanamivir. Further SAR studies of 4-amino-4H-pyran-2-carboxylic acid-6-propylamides

SAR investigations of the 4- and 5-positions of a series of 4-amino-4H-pyran-2-carboxylic acid 6-carboxamides are reported. Potent inhibitors of influenza A sialidase with marked selectivity over the influenza B enzyme were obtained when the basic 4-amino substituent was replaced by hydroxyl or even deleted. Modifications at the 5-position exhibited a tight steric requirement, with trifluoroacetamide being optimal.

Inhibition of p38 Kinase Reveals a TNF-α-Mediated, Caspase-Dependent, Apoptotic Death Pathway in a Human Myelomonocyte Cell Line

TNF-alpha transduces signals of survival or death via its two receptors, R1/p55/p60 and RII/p80/p75. The role of caspases as effectors of cell death is universally accepted, although caspase inhibitors may potentiate TNF cytotoxicity in some instances. In conditions when macromolecular synthesis is blocked, caspases are part of the machinery that executes TNF-triggered apoptotic death in U937, a human myelomonocyte cell line, and in the Jurkat T cell line. However, inhibition of p38 mitogen-activated protein kinase (p38 MAPK) triggered TNF cytotoxicity in U937 cells and murine splenic macrophages, but not the Jurkat cell line. TNF induced expression of the antiapoptotic protein c-IAP2 (cytoplasmic inhibitor of apoptosis protein 2), and was blocked in the presence of a p38 MAPK inhibitor, which also induced caspase-dependent, TNF-mediated apoptosis in U937 cells. Thus, inhibition of p38 MAPK resulted in the activation of caspase 9 and cleavage of the adaptor molecule BH3 interacting domain death agonist, and blocked NF-kappaB-mediated transactivation, without affecting the nuclear translocation of NF-kappaB. Collectively, these data show that activation of p38 MAPK is critical to cell survival by TNF in U937 cells, and demonstrate lineage-specific regulation of TNF-triggered signals of activation or apoptosis.

The role of calpain in caspase activation during etoposide induced apoptosis in T cells

T cells treated with the drug etoposide undergo apoptotic death characterized by early evidence of nuclear damage followed by loss of mitochondrial integrity and cell lysis. Calpains and caspases are cytoplasmic proteases and there is increasing evidence of cross-talk between these proteases in death pathways. In this study we have investigated the role of calpain, in etoposide-triggered apoptosis in the 2B4 murine T cell hybridoma. Cell permeable inhibitors of calpain, ALLnM, E64 and calpeptin that block Fas ligand-Fas-mediated death in T cells, blocked etoposide-induced nuclear damage, loss of mitochondrial integrity and cell lysis. A broad spectrum peptide inhibitor of caspases, ZVAD-fmk, partially blocked nuclear damage but poorly inhibited mitochondrial damage or cell lysis triggered by etoposide. Etoposide-induced expression of the cleaved, proteolytically active form of caspase 3, and DEVD-ase activity, detected prior to nuclear damage, were blocked in the presence of calpain inhibitors. Collectively, these data describe a role for calpain in regulating etoposide-induced apoptosis via a caspase-dependent pathway in T cells.

Multistate population and whole genome sequence-based strain surveillance of invasive pneumococci recovered in the USA during 2017

OBJECTIVES

We aimed to provide population-based and whole-genome sequence (WGS) -based characterization of invasive pneumococcal disease isolates collected from multistate surveillance in the USA during 2017.

METHODS

We obtained short-read WGS from 2881 isolates with associated bioinformatics pipeline strain feature predictions. For quality control, capsular serotypes and antimicrobial MICs were also obtained conventionally from 442 isolates. Annotated WGS were provided (inclusive of serotypes, MICs, multilocus sequence types, pilus type(s)) from 2723 isolates. For 158 isolates with suboptimal WGS, antimicrobial MICs were obtained conventionally.

RESULTS

There were 127 isolates from children <5 years of age and 2754 isolates from those ≥5 years old in 2017. One of 43 different serotypes was predicted for 2877 of the 2881 isolates. Serotypes in the 13-valent conjugate vaccine together with 6C (PCV13+6C) accounted for 816 (28.3%) isolates, with PCV13 serotype 3 being the most common serotype overall. Non-PCV13-6C- serotypes accounted for 2065 (71.7%) isolates, comprising 96 (75.6%) isolates from children < 5 years old and 1969 (61.4%) isolates from those aged ≥5 years. Of 36 different categories of recently emerged serotype-switch variants, three showed marked increases relative to 2015-2016 in that the number from 2017 surpassed the number from 2015-2016 combined. Two of these included antimicrobial-resistant serotype 11A and 35B serotype-switch variants of the ST156 clonal complex.

CONCLUSIONS

PCV13+6C strains are still identified in 2017 but non-PCV13-type strains impose a considerable burden. This well-annotated year 2017 WGS/strain data set will prove useful for a broad variety of analyses and improved our understanding of invasive pneumococcal disease-causing strains in the post-PCV13 era.

Combined femoral and Chiari osteotomies for reconstruction of the painful subluxation or dislocation of the hip in cerebral palsy. A long-term outcome study

In order to treat painful subluxation or dislocation secondary to cerebral palsy, 11 patients (12 hips) underwent combined femoral and Chiari pelvic osteotomies with additional soft-tissue releases at a mean age of 14.1 years (9.1 to 17.8). Relief of pain, improvement in movement of the hip, and in sitting posture, and ease of perineal care were recorded in all, and were maintained at a mean follow-up of 13.1 years (8 to 17.5). The improvement in general mobility was marginal, but those who were able to walk benefited the most. The radiological measurements made before operation were modified afterwards to use the lateral margin of the neoacetabulum produced by the pelvic osteotomy. The radiological migration index improved from a mean of 80.6% (61% to 100%) to 13.7% (0% to 33%) (p < 0.0001). The mean changes in centre edge angle and Sharp's angle were 72 degrees (56 degrees to 87 degrees; p < 0.0001) and 12.3 degrees (9 degrees to 15.6 degrees; p < 0.0001), respectively. Radiological evidence of progressive arthritic change was seen in one hip, in which only a partial reduction had been achieved, and there was early narrowing of the joint space in another. Painless heterotopic ossification was observed in one patient with athetoid quadriplegia. In seven hips the lateral Kawamura approach, elevating the greater trochanter, provided exposure for both osteotomies and allowed the construction of a dome-shaped iliac osteotomy, while protecting the sciatic nerve.

Abdominoscrotal hydrocoeles: little place for conservatism

Abdominoscrotal hydrocoeles (ASH) are infrequently reported in children. The presence of bilateral ASH is even rarer, with fewer than five cases reported to date. ASH are present at birth and tend to be progressive in nature. Spontaneous resolution has not been documented. The pathogenesis is uncertain and their presence in the neonatal period suggests a preformed abnormality of the processus vaginalis. Diagnosis is suspected on clinical examination and confirmed by ultrasonography, which is a reliable diagnostic tool. Undescended testes frequently coexist. Early surgery is the preferred management, and complications are frequent if left unattended. Surgery is simply an extension of a hernia operation, without the need for a laparotomy.

Evaluation of a novel hydrophilic derivatized capillary for protein analysis by capillary electrophoresis-electrospray mass spectrometry

A new type of hydrophilic derivatized capillary has been used to enable the on-line capillary electrophoresis separation and electrospray mass spectrometric detection of a mixture of proteins containing bovine cytochrome c, tuna cytochrome c and horse heart myoglobin. Less than 40 fmol of each compound were loaded into the capillary. Baseline resolution of components was achieved, as were accurate assignments of molecular masses. The hydrophilic derivatized capillaries were taken through extensive testing procedures to characterize their performance and capabilities for protein analysis. A mixture of six proteins (cytochrome c, ribonuclease A, alpha-chymotrypsinogen, myoglobin, carbonic anhydrase II and alpha-lactalbumin) in acetic acid-sodium acetate buffer was used to delineate the relationships between migration time and pH, along with migration time and buffer concentration for each protein. The variations in capillary efficiency as a function of pH and as a function of buffer concentration were also characterized for the same six proteins in the acetic acid-sodium acetate system. A pH of 4.8 was found to offer an excellent compromise between separation efficiency (up to 500,000 theoretical plates) and analysis time. Capillary efficiencies were also found to be very good when employing a Tris.HCl electrolyte adjusted to pH 4.8. Lastly, electropherogram reproducibility and capillary durability were examined with the finding that little deterioration of the capillary occurred over the course of 400 injections (200 h run time). This represents a notable improvement over previously documented derivatization procedures designed to reduce protein adsorption to fused-silica capillary walls.

Frequency analysis of medical concepts in clinical trials and their coverage in MeSH and SNOMED-CT

BACKGROUND

Eligibility criteria (EC) of clinical trials play a key role in selecting appropriate study candidates and the validity of the outcome of a clinical trial. However, in most cases EC are provided in unstandardised ways such as free text, which raises significant challenges for machine-readability.

OBJECTIVES

To establish a list of most frequent medical concepts in clinical trials with semantic annotations. This concept list contributes to standardisation of EC and identifies relevant data items in electronic health records (EHRs) for clinical research. The coverage of the list in two major clinical vocabularies, MeSH and SNOMED-CT, will be assessed.

METHODS

Four hundred and twenty-five clinical trials conducted between 2000 and 2011 at a German university hospital were analysed. 6671 EC were manually annotated by a medical coder using Concept Unique Identifiers (CUIs) provided by the Unified Medical Language System. Two physicians performed a semi-automatic CUI code revision. Concept frequency was analysed and clusters of concepts were manually identified.A binomial significance test was applied to quantify coverage differences of the most frequent concepts in MeSH and SNOMED-CT.

RESULTS

Based on manual medical coding of 425 clinical trials, 7588 concepts were identified, of which 5236 were distinct. A top 100 list containing 101 most frequent medical concepts was established. The concepts of this list cover 25 % of all concept occurrences in all analysed clinical trials. This list reveals six missing entries in SNOMED-CT, 12 in MeSH. The median of EC frequency per trial has increased throughout the trial years (2000 -2005: 8 EC/trial, 2011: 14 EC/trial).

CONCLUSIONS

Relatively few concepts cover one quarter of concept occurrences that represent EC in recent studies. Therefore, these concepts can serve as candidate data elements for integration into EHRs to optimise patient recruitment in clinical research.

Biochemical features of major organ of Corti proteins (OCP-I and OCP-II) including partial amino acid sequence

Further biochemical and biophysical characterization of two low-molecular-weight, strongly acidic proteins that are present at extremely high levels in the organ of Corti, tentatively named OCP-I and OCP-II, is presented. The two proteins are also present, although at much lower levels, in the vestibular end-organs and a variety of other inner ear tissues; they have not been observed in other systems. OCP-I and II are highly soluble and do not contain appreciable amounts of carbohydrate. The two proteins, originally described in the guinea pig, are compared electrophoretically with the corresponding proteins in several other mammalian species. Preliminary data on the amino acid composition of the two proteins are presented. Moreover, the amino-terminal sequence of a 22-residue segment of OCP-II is shown and compared to the sequences of known proteins.

Renal function and cardiovascular risk profile after conversion from ciclosporin to tacrolimus: prospective study in 80 liver transplant recipients

BACKGROUND

Increased risk of cardiovascular and cerebrovascular disease in liver transplant recipients results in particular from the side effects of calcineurin inhibitor-based immunosuppressive therapy. Several studies have demonstrated a more favourable outcome for patients receiving tacrolimus (TAC) as compared with ciclosporin (CS).

AIM

To investigate the effects of conversion from CS to TAC on cardiovascular risk factors and renal function in liver transplant recipients.

METHODS

In a prospective study, all except two patients had chronic kidney disease stages 2-4 (n = 80), according to estimated glomerular filtration rate using the abbreviated Modification of Diet in Renal Disease equation.

RESULTS

Conversion was accompanied with a mean decrease of total cholesterol from 194.6 +/- 54.0 mg/dL to 175.8 +/- 44.2 mg/dL (P < 0.001), low density lipoprotein cholesterol from 106.7 +/- 39.2 mg/dL to 90.9 +/- 28.6 mg/dL (P < 0.001) and mean arterial blood pressure values from 102.2 +/- 13.2 mm Hg to 95.9 +/- 11.7 mm Hg (P < 0.001). Renal function remained stable. No cases of de novo diabetes mellitus were identified. The Framingham risk score was significantly reduced from 5.2 +/- 4.4 at baseline to 4.4 +/- 5.3 after 12 months (P = 0.006).

CONCLUSIONS

Conversion from CS to TAC has been shown to improve the cardiovascular risk profile and may retard further decline of renal function after liver transplantation.

BJS commission on surgery and perioperative care post-COVID-19

BACKGROUND

Coronavirus disease 2019 (COVID-19) was declared a pandemic by the WHO on 11 March 2020 and global surgical practice was compromised. This Commission aimed to document and reflect on the changes seen in the surgical environment during the pandemic, by reviewing colleagues' experiences and published evidence.

METHODS

In late 2020, BJS contacted colleagues across the global surgical community and asked them to describe how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had affected their practice. In addition to this, the Commission undertook a literature review on the impact of COVID-19 on surgery and perioperative care. A thematic analysis was performed to identify the issues most frequently encountered by the correspondents, as well as the solutions and ideas suggested to address them.

RESULTS

BJS received communications for this Commission from leading clinicians and academics across a variety of surgical specialties in every inhabited continent. The responses from all over the world provided insights into multiple facets of surgical practice from a governmental level to individual clinical practice and training.

CONCLUSION

The COVID-19 pandemic has uncovered a variety of problems in healthcare systems, including negative impacts on surgical practice. Global surgical multidisciplinary teams are working collaboratively to address research questions about the future of surgery in the post-COVID-19 era. The COVID-19 pandemic is severely damaging surgical training. The establishment of a multidisciplinary ethics committee should be encouraged at all surgical oncology centres. Innovative leadership and collaboration is vital in the post-COVID-19 era.

Aβ Produced as a Fusion to Maltose Binding Protein Can Be Readily Purified and Stably Associates with Copper and Zinc

The 42 amino acid Alzheimer's Abeta peptide has been produced in E. coli as a soluble fusion to maltose binding protein (MBP). Affinity purification on amylose columns of MBP-Abeta and MBP led to the recovery of proteins at purities that were suited for physicochemical analyses. MBP-Abeta was able to bind approximately 2 mole equivalents of copper or 4 mole equivalents of zinc, while MBP alone bound negligible amounts of zinc or copper. We conclude that Abeta can bind 2 copper or 4 zinc ions in its fusion format. Because MBP-Abeta is a convenient protein to work with, this system is well suited for further studies on the structure of Abeta and its interactions with metals.

The efficacy, tolerability and safety of diethylcarbamazine-fortified salt in the treatment of the microfilaraemias of brugian filariasis: an open, hospital-based study

Cooking salt fortified with diethylcarbamazine (DEC) has been successfully used to control lymphatic filariasis in several parts of the world. The kinetics and efficacy of DEC-fortified salt in clearing microfilaraemias of Brugia malayi and the salt's tolerability and safety are examined in this study. Twenty individuals with B. malayi microfilaraemias (pre-treatment levels of 108-6358 microfilariae/ml; median = 309/ml) consumed DEC-fortified salt (0.2%, w/w) with their food for 1 year, initially in hospital (for 1 week) and later at home. The mean daily intake of DEC was 21.4 mg (range = 9.0-39.4 mg). Even on the first day of consuming the salt, there was a decrease in the microfilarial levels of 14 patients and a sharp increase in six patients. Microfilarial levels tended to fluctuate thereafter but there was a progressive, general decline. At the end of the study year, eight patients were amicrofilaraemic and microfilarial clearance was > 95% in 58% of the patients. Eight patients did not develop any adverse reactions. Lymph-node tenderness and enlargement were seen in eight patients (40%), and dilated, inflamed lymphatic channels standing out as cords ('string sign') were seen in another five patients. These reactions were transient and did not require any specific treatment. The DEC-fortified salt was well accepted by the study population. The DEC content of fortified salt and the duration of its use for the control of brugian filariasis need to be re-examined. Health education should include messages that mild, self-limiting, adverse reactions are likely to occur even with the use of such salt.

Prospective comparison of MRA with catheter angiography in the assessment of patients with aortoiliac occlusion before surgery or endovascular therapy

AIM

The purpose of this study was to evaluate the usefulness of gadolinium enhanced 3D magnetic resonance (MR) angiography (CE MRA) as an alternative to translumbar or brachial angiography in the pre-operative work-up of patients with aortoiliac occlusion.

MATERIALS AND METHODS

Nineteen patients (14 men and five women; age range 45-77 years; mean 62 years), not suitable for perfemoral angiography (aortoiliac occlusion, n = 18; infected femoro-femoral graft with femoral artery pseudoaneurysm, n = 1), underwent pre-operative CE MRA and catheter angiography (translumbar, n = 5; brachial, n = 14). CE MRA was performed using a 3D fast spoiled gradient-recalled pulse sequence during the intravenous injection of 40 ml of gadolinium DTPA and a 32-s breath-hold. All patients subsequently underwent surgical (n = 13) or percutaneous transluminal (n = 6) treatment for their vascular disease. The accuracy of CE MRA was determined compared with the findings at catheter angiography taken as the gold standard.

RESULTS

CE MRA gave accurate information about the occlusion, inflow and distal run-off in the majority of patients. CE MRA revealed occlusions with an accuracy of 94.7% in the aortic segment, 98.7% in the iliac segment, and 100% in the common femoral segment. The arterial segments distal to the common femoral artery were not completely visualized in four patients but CE MRA provided sufficient information to plan either surgical or percutaneous transluminal therapy in all but one patient.

CONCLUSION

CE MRA is highly accurate in showing the presence and extent of aortoiliac occlusions. In our study group, CE MRA gave sufficient information in the pre-operative evaluation of aortoiliac occlusion.

Role of sialylation in determining the pharmacokinetics of neutrophil inhibitory factor (NIF) in the Fischer 344 rat

1. Recombinant neutrophil inhibitory factor (NIF) is a glycoprotein. Its amino acid sequence remains constant and has a molecular weight of 28.9 kD. However, approximately 40% of the total molecular weight consists of glycans with variable structure. 2. The pharmacokinetics of 11 different NIF batches with varying extents and patterns of sialylation have been investigated in the Fischer 344 rat following intravenous administration. These data indicate that reducing the extent of NIF sialylation reduces the half-life of the molecule due to an increase in the systemic clearance. Also, an increase in the number of unsialylated or neutral glycans may increase the volume of distribution of NIF, although this effect is marginal. 3. Isolated perfused rat liver (IPRL) investigations have shown that sialylated NIF has a low hepatic extraction (< 1%), while asialo NIF has an extraction that is > 20-fold higher. Co-administration of asialo NIF with asialo fetuin (a protein cleared by hepatic asialoglycoprotein receptor (possibly galactose)-mediated uptake reduced the hepatic extraction of asialo NIF. 4. These data suggest that NIF molecules that have free sugar moieties (possibly galactose) interact with an asialoglycoprotein receptor (possibly galactose-mediated) in the liver (parenchymal cells/hepatocytes). Interaction with this receptor leads to cellular internalization and degradation.

“Achieving Optimal Clinical Outcomes in Autologous Fat Grafting: A Systematic Review of Processing Techniques”

BACKGROUND

Autologous fat grafting (AFG) is a versatile technique in reconstructive and cosmetic surgery. Graft processing is a key source of variability resulting in unreliable clinical outcomes, with no consensus on the optimal methodology. This systematic review identifies the evidence base supporting different processing paradigms.

METHODS

A systematic literature search was conducted using the PubMed, Scopus and The Cochrane Foundation databases. Studies comparing AFG processing methods and reporting long-term patient outcomes were identified.

RESULTS

Twenty-four studies (2413 patients) were identified. Processing techniques evaluated included centrifugation, decantation, washing, filtration, gauze rolling, as well as commercial devices and adipose-derived stem/stromal cell (ASC) enrichment methods. Objective volumetric and subjective patient-reported outcomes were discussed. There was a variable reporting of complications and volume retention rates. Complications were infrequent; palpable cysts (0-20%), surgical-site infections (0-8%) and fat necrosis (0-58.4%) were the most reported. No significant differences in long-term volume retention between techniques were found in AFG in the breast. In head and neck patients, greater volume retention was documented in ASC enrichment (64.8-95%) and commercial devices (41.2%) compared to centrifugation (31.8-76%).

CONCLUSIONS

Graft processing through washing and filtration, including when incorporated into commercial devices, results in superior long-term outcomes compared to centrifugation and decantation methods. ASC enrichment methods and commercial devices seem to have superior long-term volume retention in facial fat grafting.