Practice patterns in management of differentiated thyroid cancer since the 2014 British Thyroid Association (BTA) guidelines.

BACKGROUND: The updated 2014 BTA guidelines emphasised a more conservative, risk adapted model for the management of low-risk differentiated thyroid cancer (DTC). In comparison to historical approach of total thyroidectomy combined with radioactive iodine, treatment de-escalation is increasingly supported. AIMS: To evaluate the impact of the updated BTA guidelines on the management of DTC cases at regional UK centre. METHODS: All DTC patients were retrospectively identified from regional thyroid MDT database between Jan2009-Dec2020. Oncological treatment and clinico-pathological characteristics were analysed. RESULTS: 623 DTC cases were identified; 312 (247 female: 65 male) between 2009 and 2014 and 311 (225 female: 86 male) between 2015 and 2020. Median age is 48 years (range 16-85). By comparing pre- and post-2015 cohorts, there was a significant drop in total thyroidectomy (87.1% vs 76.8%, p = 0.001) and the use of radioactive iodine (RAI) (73.1% vs 62.1%, p = 0.003) in our post-2015 cohort. When histological adverse features were analysed, extra-thyroidal extension (4.2% vs 17.0%, p=< 0.001), lymphovascular invasion (31.4% vs 50.5%, p=<0.001) and multi-centricity (26.9% vs 43.4%, p = 0.001) were significantly increased in the post 2015 cohort. Nonetheless, total thyroidectomy (TT) remains the treatment choice for low risk T1/2 N0 M0 disease in 65.3% (124/190) in post-2015 cohort for several reasons. Reasons include adverse histological features (50.8%), benign indications (32.5%), contralateral nodules (11.7%), patient preference (2.5%), and diagnostic uncertainty (2.5%). CONCLUSION: Our study confirms a move towards a more conservative approach to patients with low-risk DTC in the UK, which is in keeping with the BTA 2014 guideline and international trends, but total thyroidectomy remains prevalent for low risk T1/2 N0 M0 disease for other reasons.

In Sickness and in Health: The Relationships Between Bacteria and Bile in the Human Gut.

Colonization of a human host with a commensal microbiota has a complex interaction in which bacterial communities provide numerous health benefits to the host. An equilibrium between host and microbiota is kept in check with the help of biliary secretions by the host. Bile, composed primarily of bile salts, promotes digestion. It also provides a barrier between host and bacteria. After bile salts are synthesized in the liver, they are stored in the gallbladder to be released after food intake. The set of host-secreted bile salts is modified by the resident bacteria. Because bile salts are toxic to bacteria, an equilibrium of modified bile salts is reached that allows commensal bacteria to survive, yet rebuffs invading pathogens. In addition to direct toxic effects on cells, bile salts maintain homeostasis as signaling molecules, tuning the immune system. To cause disease, gram-negative pathogenic bacteria have shared strategies to survive this harsh environment. Through exclusion of bile, efflux of bile, and repair of bile-induced damage, these pathogens can successfully disrupt and outcompete the microbiota to activate virulence factors.

A cost-effective protocol for screening patients for methicillin-resistant Staphylococcus aureus.

The incidence of hospital-acquired infection with methicillin-resistant Staphylococcus aureus (MRSA) is rising worldwide. Rapid identification of MRSA carriers is an important step in reducing the risk of transmission to other patients. Molecular methods are increasingly popular but are technically demanding and expensive. This study assesses the modification of one of the commercially available latex agglutination tests (Mastalex-MRSA) for the identification of penicillin-binding protein 2' on known strains of MRSA as well as other organisms identified from chromogenic agar plates. A total of 3050 patients with unknown MRSA status were processed through the routine laboratory during the investigation period and 73 of these were presumptive positive following overnight incubation. Of 70 patients who could be evaluated, 32 (43.8%) specimens would be suitable for use with the kit directly from overnight incubation on chromogenic agar, and the other 38 (52.1%) would be suitable following four hours' incubation on blood agar. The cost of one positive MRSA test with the inclusion of this test is Euro 15.15 compared with published reports of Euro 35.00 for a commercial polymerase chain reaction (PCR) test. This protocol would allow the reporting of presumptive positive MRSA results approximately 24 hours earlier than currently achieved.

Complications and predisposing factors from a decade of total laryngectomy.

BACKGROUND: Total laryngectomy is often utilised to manage squamous cell carcinoma of the larynx or hypopharynx. This study reports on surgical trends and outcomes over a 10-year period. METHOD: A retrospective review of patients undergoing total laryngectomy for squamous cell carcinoma was performed (n = 173), dividing patients into primary and salvage total laryngectomy cohorts. RESULTS: A shift towards organ-sparing management was observed. Primary total laryngectomy was performed for locoregionally advanced disease and utilised reconstruction less than salvage total laryngectomy. Overall, 11 per cent of patients developed pharyngocutaneous fistulae (primary: 6 per cent; salvage: 20 per cent) and 11 per cent neopharyngeal stenosis (primary: 9 per cent; salvage: 15 per cent). Pharyngocutaneous fistulae rates were higher in the reconstructed primary total laryngectomy group (24 per cent; 4 of 17), compared with primary closure (3 per cent; 3 of 90) (p = 0.02). Patients were significantly more likely to develop neopharyngeal stenosis following pharyngocutaneous fistulae in salvage total laryngectomy (p = 0.01) and reconstruction in primary total laryngectomy (p = 0.02). Pre-operative haemoglobin level and adjuvant treatment failed to predict pharyngocutaneous fistulae development. CONCLUSION: Complications remain hard to predict and there are continuing causes of morbidity. Additionally, prior treatment continues to affect surgical outcomes.

Testing by Sysmex UF-100 flow cytometer and with bacterial culture in a diagnostic laboratory: a comparison.

A large proportion of the samples tested in routine diagnostic microbiology laboratory are urine samples. The gold standard is bacterial culture, but a high proportion of samples cultured are negative. Unnecessary testing can be reduced and an improved service provided by an effective screening test. The Sysmex UF-100 flow cytometer has been developed to count cells and casts accurately in urine samples. Its performance in a screening test was compared with bacterial culture by using 1005 consecutive urine samples, and cut-off criteria were established. Cut-off values of 3000 bacteria/microl and 111 WBC/microl provided the best discrimination. Of 1005 samples, 606 (60%) would be cultured. Sixteen samples that were not selected according to these criteria were culture positive. This was considered acceptable for our routine use. The use of a testing algorithm incorporating the Sysmex UF-100 flow cytometer has improved the quality and efficiency of urine testing within the routine microbiology laboratory.

Emergence and transmission of influenza A viruses resistant to amantadine and rimantadine.

Amantadine- and rimantadine-resistant viruses have been recovered from approximately 30% of patients treated for acute H3N2 subtype influenza and less often from their close contacts receiving drug prophylaxis. The limited data suggest that resistant viruses can emerge rapidly during drug therapy, as early as 2-3 days into treatment. These viruses retain their resistance phenotype during multiple passages in the laboratory and appear to be genetically stable in this regard. Studies in families and in nursing homes indicate that resistant isolates appear to be transmissible from treated patients and cause typical influenza in contacts receiving drug prophylaxis. It is unknown whether resistant human viruses are capable of competing with wild-type ones during multiple cycles of infection in the absence of the drug. These viruses appear to be pathogenic, and no evidence indicates that they differ from wild-type strains. Thus, these viruses clearly possess the biologic properties that are associated with clinically important drug resistance. However, limited information is available to assess their actual impact. It is unknown what degree of selective drug pressure would be required to cause substantial transmission of resistant viruses during community outbreaks. Natural selection of antigenic variants and disappearance of previous variants may prevent the emergence of viruses that have been altered in the genes coding both for the surface glycoproteins and for the M2 protein. However, the emergence of drug-resistant influenza viruses appears to pose potential clinical problems in certain epidemiologic situations involving close contact with treated patients.

Certain phosphoramidate derivatives of dideoxy uridine (ddU) are active against HIV and successfully by-pass thymidine kinase.

As part of our effort to deliver masked phosphates inside living cells we have discovered that certain phosphate triester derivatives of the inactive nucleoside analogue, dideoxy uridine (ddU) are inhibitors of HIV replication at microM levels. Moreover, we note that certain phosphoramidate derivatives retain their activity in thymidine kinase-deficient cells, which indicates that they do indeed act by intracellular release of the free nucleotide, and that they successfully by-pass the nucleoside kinase. The increased structural freedom in drug design which this allows may have implications for dealing with the emergence of resistance and may stimulate the discovery of improved therapeutic agents.

An ELISA utilizing immobilised snowdrop lectin GNA for the detection of envelope glycoproteins of HIV and SIV.

A simple, reliable ELISA for the quantitative detection of the envelope glycoproteins of both HIV and SIV is described. It incorporates the snowdrop lectin GNA to capture the glycoprotein antigens and combines the high selectivity of GNA binding with its broad reactivity with the glycoproteins of HIV-1, HIV-2 and SIV.

Regulation of pH by the M2 protein of influenza A viruses.

Inhibition of the function of the M2 protein by amantadine can cause a conformational change in the haemagglutinin (HA) of H7 influenza A viruses and the consequent expression of the low pH form of the glycoprotein on the surface of virus-infected cells. Immunofluorescence studies showed that this conversion occurs shortly after HA exists from the Golgi complex apparently during its transport through the trans Golgi network and using the pH probe, DAMP/anti-DNP, that it is the direct result of reduced vesicular pH. The lowest pHs encountered were estimated using mutant HAs differing in pH stability to be approximately 5.2 and 5.6 in virus-infected CEF or MDCK cells, respectively, in the absence of functional M2. Depending on the particular M2, this protein was responsible for increases in vesicular pH of up to 0.8 units. The influence of mutations in both HA and M2 on the maturation of native HA illustrates the important relationship between the structural and functional properties of these two proteins. Using the fluorescent probe SNARF-1 the M2 protein was also shown to be largely responsible for the 0.3-0.4 unit reduction in intracellular pH of virus-infected cells. The data thus provide further evidence for the pH regulatory function of M2 and its importance for the maturation of the HA glycoprotein.

Toxic inhibition of smooth muscle contractility by plant-derived sesquiterpenes caused by their chemically reactive alpha-methylenebutyrolactone functions.

1. Previous studies have shown that extracts of feverfew (Tanacetum parthenium) and parthenolide, a sesquiterpene alpha-methylenebutyrolactone obtained from it, inhibit smooth muscle contractility in a time-dependent, non-specific and irreversible manner. 2. The hypothesis that this toxic effect is due specifically to the presence in the sesquiterpene lactone of the potentially reactive alpha-methylene function was tested on rabbit isolated aortic ring preparations. This was done (a) by comparing the effects of two plant-derived sesquiterpene lactones purified from yellow star thistle (Centaurea solstitialis): cynaropicrin (an alpha-methylenebutyrolactone) and solstitialin 13-acetate (lacking the alpha-methylene function), and (b) by chemically inactivating the alpha-methylene functions in cynaropicrin and parthenolide by reaction with cysteine. 3. The results show that the characteristic smooth muscle inhibitory profile is demonstrated by the two alpha-methylenebutyrolactones (parthenolide and cynaropicrin), but not by the compound lacking this functional group (solstitialin 13-acetate), or by those previously active compounds in which it has been inactivated with cysteine. 4. Thus the alpha-methylene function is critical for this aspect of the toxic pharmacological profile of the sesquiterpene butyrolactones, which are natural products widely distributed in the Compositae family of flowering plants.

In vitro anti-influenza virus activity of a plant preparation from Geranium sanguineum L.

A polyphenolic complex (PC), isolated from the Bulgarian medicinal plant Geranium sanguineum L., was shown to have selective anti-influenza activity in vitro. Expression of HA on the surface of cells infected with A/chicken/Rostock/34, virus-induced cytopathic effect, infectious virus yield and plaque formation were all reduced at non-toxic concentrations of PC. Synthesis of virus proteins was also selectively inhibited. High concentrations of PC (> 200 microg/ml) exhibited a strong virucidal effect. Although the action was directed against an early stage of infection (within 3 h of infection), the process directly affected was not identified. The selectivity of antiviral action was confirmed by the variation in sensitivity of different influenza viruses to PC and the selection of variants with reduced drug sensitivity.

Synthesis and anti-HIV activity of some novel diaryl phosphate derivatives of AZT.

Novel diaryl phosphate triester derivatives of the anti-HIV nucleoside analogue AZT have been prepared by phosphorochloridate chemistry. These materials were designed to act as membrane-soluble pro-drugs of the bio-active free nucleotides. In particular, novel parasubstituted diaryl phosphate derivatives were prepared. In vitro evaluation revealed the compounds to have a pronounced and selective antiviral effect, the magnitude of which varied considerably with the nature of the aryl substituent. In particular, strongly electron-withdrawing aryl substituents correlate with high anti-HIV potency in C8166 cells. Along with AZT, the compounds are poorly effective in JM cells, which appear to lack thymidine kinase, indicating the phosphates to act as pro-drugs of the nucleoside rather than of the free phosphate.

Anti-influenza virus activity of the compound LY253963.

The compound LY253963 (1,3,4-thiadiazol-2-ylcyanamide) inhibited the in vitro replication of representative influenza A and B viruses in Madin-Darby canine kidney (MDCK) cells at concentrations of 1-3.2 micrograms/ml. The yield of an influenza A (H3N2) virus in primary rhesus monkey kidney (RMK) cells was inhibited at 0.1-0.3 micrograms/ml. However, similar concentrations were inhibitory for the growth of uninfected MCDK or RMK cells. Combination drug studies generally found indifferent interactions between LY253963 and ribavirin or rimantadine. In timing of additional studies, hemagglutinin expression was inhibited to the greatest extent when LY253963 exposure was begun at least 8 h before viral infection, which suggested either slow uptake or intracellular metabolism of LY253963 to an active form. Virus-specific protein synthesis was inhibited to a greater extent by ribavirin 10 micrograms/ml or rimantadine 1 microgram/ml than by LY253963 10 micrograms/ml. No drug-resistant mutants were detected during serial passage of an influenza A (H3N2) virus in the presence of LY253963 1-16 micrograms/ml. In summary, we found that LY253963 inhibited influenza A and B virus replication in several cell types, but that it was associated with cytostatic effects at low concentrations. These studies failed to identify a selective anti-influenza action.

Aryl phosphate derivatives of AZT retain activity against HIV1 in cell lines which are resistant to the action of AZT.

Novel aryl phosphate derivatives of the anti-HIV nucleoside analogue AZT have been prepared by phosphorochloridate chemistry. These materials are designed to act as membrane-soluble pro-drugs of the bio-active free nucleotides. In vitro evaluation revealed the compounds to have a pronounced, selective antiviral activity, which, in one case, was more potent than the parent nucleoside AZT. The magnitude of the biological effect varied considerably with the nature of the phosphate-blocking group. Moreover, one of the compounds, a phosphoramidate, is particularly active in a cell line restrictive to the activity of AZT, due to poor phosphorylation therein. These data support the suggestion that the phosphate derivatives exert their biological effects via intracellular release of the nucleotide forms.

Inhibition of HIV infection by flavanoids.

Of a variety of flavanoids, the flavans were generally more effective than flavones and flavanones in selective inhibition of HIV-1, HIV-2 or SIV infection. Studies of their effects on the binding of sCD4 and antibody to gp120 indicated that the effective compounds interact irreversibly with gp120 to inactive virus infectivity and block infection.

Polymerase chain reaction for screening clinical isolates of corynebacteria for the production of diphtheria toxin.

AIMS: To assess the performance of the polymerase chain reaction (PCR) when used to screen rapidly large numbers of corynebacteria for toxin production; and to determine the incidence of false positive PCR results with non-toxigenic Corynebacterium diphtheriae isolates. METHODS: Eighty seven recent British isolates of corynebacteria were assayed by PCR. All isolates were assayed from both blood and tellurite agar within a five day period. Thirty three non-toxigenic isolates of C diphtheriae from six countries were also tested by PCR and by the Elek immunodiffusion assay. RESULTS: There was complete concordance between the results of PCR and traditional methods on the recent British isolates, with one exception: an Elek positive "C ulcerans" isolate, which was PCR positive from tellurite but not from blood agar. One of the thirty three (3%) non-toxigenic isolates of C diphtheriae was PCR positive. CONCLUSIONS: These results suggest that PCR compares favourably with traditional methods for the detection of toxigenic corynebacteria and that it represents a powerful new tool in the diagnosis of an old disease.

The isolation and immunochemical characterisation of a cell-wall carbohydrate and a membrane lipocarbohydrate antigen of group B streptococcus, type II.

Two distinct carbohydrate antigens were isolated from the cell surface of group B streptococcus, type II. One antigen was extracted from SDS-purified cell walls by cold trichloroacetic acid and contained galactose, glucose, rhamnose, glucosamine and sialic acid in the approximate molar proportions 1.7:1.0:3.4:0.9:0.21 respectively. The serological activity of this polymer indicated that it is the group-specific antigen common to all group B streptococci. The second antigen was extracted by phenol from cell membranes and contained galactose, glucose, glucosamine, phosphorus and fatty acid in a molar ratio of 1.6:1.0:0.35:2.6:0.016 respectively. This antigen was shown to be specific for type II, group B streptococcus.

D-xylan-degrading enzyme system from the fungus Phanerochaete chrysosporium: isolation and partial characterisation of an alpha-(4-O-methyl)-D-glucuronidase.

A number of fungi were screened for their capacities to produce extracellular alpha-(4-O-methyl)-D-glucuronidase. Of those tested, Phanerochaete chrysosporium ATCC 24725 produced the enzyme in greatest yield. The single alpha-(4-O-methyl)-D-glucuronidase produced by this fungus was purified by a series of chromatographic methods involving anion exchange, hydrophobic interaction and chromatofocusing. Isolated in this way, the enzyme had an apparent molecular mass of 112 kDa in sodium dodecyl sulphate polyacrylamide gels, and a pI of 4.6 when determined by isoelectric focusing in polyacrylamide gels. The enzyme was optimally active at pH 3.5, but showed significant activity over the pH range 3-5. In the absence of substrate the enzyme was inactivated at pH 3.5 in 2 h at 50 degree C: at pH 5.0 it retained 42% of its activity for 24 h at this temperature. The enzyme showed little activity on glucuronoxylan polysaccharides, but some short-chain xylo-oligosaccharides which were substituted with alpha-linked 4-O-methyl-D-glucopyranosyl uronic acid attached to the 2-position of the non-reducing D-xylopyranosyl residue were readily hydrolysed. There were marked synergistic effects apparent in the release of 4-O-methyl-D-glucopyranosyl uronic acid from various glucuronoxylans when the alpha-(4-O-methyl)-D-glucuronidase was acting in concert with endo-(1-->4)-beta-D-xylanase, and with beta-D-xylosidase and/or an alpha-L-arabinofuranosidase.

The carbohydrate units of asialo-ovomucoid: their heterogeneity and enzymic degradation.

An ovomucoid variant free from sialic acid has been prepared in a pure state by ion-exchange chromatography on DEAE-cellulose. The purified glycoprotein contained 10-11 residues of mannose, 2-3 residues of galactose, and 21 residues of 2-acetamido-2-deoxyglucose. Glycopeptides have been prepared by exhaustive digestion with Pronase followed by ion-exchange chromatography on Dowex 50 (X2) resin. Three fractions were obtained, all with similar contents of mannose and hexosamine but with various contents of galactose. The sugar-aspartic acid ratios indicated that all of the fractions were heterogeneous, the major fraction having mannose-galactose-hexosamine-aspartic acid ratios of 2.6:0.5:5.8:1.0. Cleavage of asialo-ovomucoid with cyanogen bromide and proteolytic digestion of the isolated fragments gave two heterogeneous glycopeptide fractions of similar composition. Both asialo-ovomucoid and the principal glycopeptide fraction were degraded with beta-D-galactosidase, alpha-D-mannosidase, and beta-N-acetylglucosaminidase singly and in sequence. Removal of much of the carbohydrate from asialo-ovomucoid had no appreciable effect on its anti-tryptic activity. By sequential degradation of the glycopeptide, a pentasaccharide core alpha-D-Man-[alpha-D-Man]-beta-D-Man-beta-D-GlcNAc-beta-D-GlcNAc-Asn was obtained. Other structural features revealed by enzymic degradation are discussed.