Severe acute myositis and myocarditis on initiation of 6-weekly pembrolizumab post-COVID-19 mRNA vaccination

We describe three cases of critical acute myositis with myocarditis occurring within 22 days of each other at a single institution, all within 1 month of receiving the initial cycle of the anti-PD-1 drug pembrolizumab. Analysis of T cell receptor repertoires from peripheral blood and tissues revealed a high degree of clonal expansion and public clones between cases, with several T cell clones expanded within the skeletal muscle putatively recognizing viral epitopes. All patients had recently received a COVID-19 mRNA booster vaccine prior to treatment and were positive for SARS-CoV2 Spike antibody. In conclusion, we report a series of unusually severe myositis and myocarditis following PD-1 blockade and the COVID-19 mRNA vaccination.

IL7 genetic variation and toxicity to immune checkpoint blockade in patients with melanoma

Treatment with immune checkpoint blockade (ICB) frequently triggers immune-related adverse events (irAEs), causing considerable morbidity. In 214 patients receiving ICB for melanoma, we observed increased severe irAE risk in minor allele carriers of rs16906115, intronic to IL7. We found that rs16906115 forms a B cell-specific expression quantitative trait locus (eQTL) to IL7 in patients. Patients carrying the risk allele demonstrate increased pre-treatment B cell IL7 expression, which independently associates with irAE risk, divergent immunoglobulin expression and more B cell receptor mutations. Consistent with the role of IL-7 in T cell development, risk allele carriers have distinct ICB-induced CD8+ T cell subset responses, skewing of T cell clonality and greater proportional repertoire occupancy by large clones. Finally, analysis of TCGA data suggests that risk allele carriers independently have improved melanoma survival. These observations highlight key roles for B cells and IL-7 in both ICB response and toxicity and clinical outcomes in melanoma.

Checkpoint-blocker-induced autoimmunity is associated with favourable outcome in metastatic melanoma and distinct T-cell expression profiles

BACKGROUND

Immune checkpoint blockers (ICBs) activate CD8⁺ T cells, eliciting both anti-cancer activity and immune-related adverse events (irAEs). The relationship of irAEs with baseline parameters and clinical outcome is unclear.

METHODS

Retrospective evaluation of irAEs on survival was performed across primary (N = 144) and secondary (N = 211) independent cohorts of patients with metastatic melanoma receiving single agent (pembrolizumab/nivolumab-sICB) or combination (nivolumab and ipilimumab-cICB) checkpoint blockade. RNA from pre-treatment and post-treatment CD8⁺ T cells was sequenced and differential gene expression according to irAE development assessed.

RESULTS

58.3% of patients developed early irAEs and this was associated with longer progression-free (PFS) and overall survival (OS) across both cohorts (log-rank test, OS: P < 0.0001). Median survival for patients without irAEs was 16.6 months (95% CI: 10.9-33.4) versus not-reached (P = 2.8 × 10^-6). Pre-treatment monocyte and neutrophil counts, but not BMI, were additional predictors of clinical outcome. Differential expression of numerous gene pathway members was observed in CD8⁺ T cells according to irAE development, and patients not developing irAEs demonstrating upregulated CXCR1 pre- and post-treatment.

CONCLUSIONS

Early irAE development post-ICB is associated with favourable survival in MM. Development of irAEs is coupled to expression of numerous gene pathways, suggesting irAE development in-part reflects baseline immune activation.

Mucosal-associated invariant T (MAIT) cells are activated in the gastrointestinal tissue of patients with combination ipilimumab and nivolumab therapy-related colitis in a pathology distinct from ulcerative colitis

The aim of this study was to investigate the pathogenesis of combination ipilimumab and nivolumab-associated colitis (IN-COL) by measuring gut-derived and peripheral blood mononuclear cell (GMNC; PBMC) profiles. We studied GMNC and PBMC from patients with IN-COL, IN-treated with no adverse-events (IN-NAE), ulcerative colitis (UC) and healthy volunteers using flow cytometry. In the gastrointestinal-derived cells we found high levels of activated CD8⁺ T cells and mucosal-associated invariant T (MAIT) cells in IN-COL, changes that were not evident in IN-NAE or UC. UC, but not IN-C, was associated with a high proportion of regulatory T cells (T_reg ). We sought to determine if local tissue responses could be measured in peripheral blood. Peripherally, checkpoint inhibition instigated a rise in activated memory CD4⁺ and CD8⁺ T cells, regardless of colitis. Low circulating MAIT cells at baseline was associated with IN-COL patients compared with IN-NAE in one of two cohorts. UC, but not IN-COL, was associated with high levels of circulating plasmablasts. In summary, the alterations in T cell subsets measured in IN-COL-affected tissue, characterized by high levels of activated CD8⁺ T cells and MAIT cells and a low proportion of T_reg , reflected a pathology distinct from UC. These tissue changes differed from the periphery, where T cell activation was a widespread on-treatment effect, and circulating MAIT cell count was low but not reliably predictive of colitis.

Intravenous high-dose interferon with or without maintenance treatment in melanoma at high risk of recurrence: meta-analysis of three trials

Resected stage IIB–IIIC malignant melanoma has a poor prognosis with a high risk of relapse and death. Treatment with adjuvant interferon alfa‐2b (IFN‐α‐2b) is associated with improved relapse‐free and overall survivals (OS), but the most appropriate dose and duration of treatment are unknown. In this article, we present an individual patient data random effects meta‐analysis of melanoma patients from the U.K., Greek, and Chinese randomized trials. All patients were randomized either to IFN‐α‐2b 15–20 MIU/m²IV daily 5 days per week for 4 weeks (IV) or to the same regimen followed by IFN‐α‐2b 9–10 MIU/m² administered three times per week for 48 weeks (IV and SC). Allowing for dose interruptions and reductions, an equivalent total dose of IFN‐α‐2b was delivered in all three studies. We assessed whether IV was noninferior to IV and SC in terms of relapse‐free survival (RFS) and investigated tumor and patient characteristics that impacted on outcomes. Median follow‐up of 716 stage IIB–IIIC patients was 5.4 years. Noninferiority of IV compared to IV and SC could not be conferred for RFS (hazard ratio [HR] 1.16, 95% confidence interval [CI] 0.89–1.52; noninferior P = 0.17). Stage (P < 0.0001), site (acral vs. other, P < 0.0001), and Breslow thickness (P = 0.02) were significant predictors of RFS. The HR for death was 1.13 for IV compared to IV and SC, (95% CI 0.91–1.39). Stage (P < 0.0001) and Breslow thickness (P = 0.001) were significant independent predictors of OS. The available data suggest that where adjuvant high‐dose interferon is being considered there is no evidence to deviate from the year long regimen described in the Eastern Cooperative Oncology Group and Intergroup studies.

Trabectedin in Advanced High-Grade Uterine Leiomyosarcoma: A Case Report Illustrating the Value of (18)FDG-PET-CT in Assessing Treatment Response

We report the case of a 60-year-old woman with metastatic high-grade uterine leiomyosarcoma who achieved a delayed response to second-line therapy with the marine-derived drug trabectedin (Yondelis(®), PharmaMar). We used 2-deoxy-2-[(18)F] fluorodeoxyglucose (FDG)-positron emission tomography (PET-CT) imaging as a tool for response monitoring in parallel with conventional re-staging according to Response Evaluation Criteria in Solid Tumours (RECIST) using computed tomography (CT). We illustrate the role of serial (18)FDG-PET-CT imaging in the functional assessment of tumour response. Three cycles after commencement of trabectedin treatment, a reduction of the maximum standardized uptake value (SUVmax) of the solid component of the pelvic mass was observed, indicating a cystic or necrotic response in the tumour to trabectedin. After 7 cycles of treatment, on (18)FDG-PET-CT there was clear evidence of ongoing disease improvement: the solid pelvic components were at worst stable, with an unchanged SUVmax, and possibly marginally reduced in size, while the pulmonary metastases had further reduced in size and become FDG negative; the bony metastases were stable. After a total of 13 cycles of treatment, administered over 13 months, the patient showed signs of progression on an (18)FDG-PET-CT scan. The safety profile of trabectedin remained manageable, showing no evidence of cumulative toxicity and being associated with a preserved quality of life. This report illustrates potential limitations of RECIST in response assessments and the critical role of serial (18)FDG-PET-CT imaging in assessing response to trabectedin treatment. Therefore, we propose that (18)FDG-PET-CT may improve the assessment of response to trabectedin in selected patients.

Phase II pilot study of intravenous high-dose interferon with or without maintenance treatment in melanoma at high risk of recurrence

PURPOSE

High-dose interferon alfa-2b (HDI) has emerged as a potentially effective adjuvant therapy in patients with resected melanoma at high risk of recurrence. Evidence suggests it may be the early, very-high-dose part of the regimen that is critical. This pilot study sought to provide an early indication of whether the same effects can be achieved with the intravenous component of HDI alone and inform the feasibility and design of a phase III trial.

PATIENTS AND METHODS

Patients with stage 2B, 2C, 3B, and 3C melanoma were randomly assigned to receive interferon alfa-2b (IFN-α-2b) 20 MIU/m(2) intravenously (IV) daily 5 days per week for 4 weeks (arm A) versus the same regimen followed by IFN-α-2b 10 MIU/m(2) administered subcutaneously three times per week for 48 weeks (arm B) and observed for relapse-free survival (RFS) and overall survival.

RESULTS

Between 2003 and 2009, 194 patients were enrolled (arm A, 96; arm B, 98). After median follow-up of 39.5 months, RFS was 22.7 months (95% CI, 14.1 to 38.1 months) in arm A versus 33.3 months (95% CI, 18.2 to not reached) in arm B (P = .28). The proportions of patients free of relapse at 2 years were 50% and 54.1% (P = .569; hazard ratio, 0.89), respectively. Overall survival favored arm B (median, 41.5 months v not reached; P = .05).

CONCLUSION

Clinical outcomes were better in patients who had the longer regimen. Our results do not support either the use of a month of IV HDI alone in place of the year-long regimen or the initiation of a larger trial on this question.

FBH1 helicase disrupts RAD51 filaments in vitro and modulates homologous recombination in mammalian cells

Efficient repair of DNA double strand breaks and interstrand cross-links requires the homologous recombination (HR) pathway, a potentially error-free process that utilizes a homologous sequence as a repair template. A key player in HR is RAD51, the eukaryotic ortholog of bacterial RecA protein. RAD51 can polymerize on DNA to form a nucleoprotein filament that facilitates both the search for the homologous DNA sequences and the subsequent DNA strand invasion required to initiate HR. Because of its pivotal role in HR, RAD51 is subject to numerous positive and negative regulatory influences. Using a combination of molecular genetic, biochemical, and single-molecule biophysical techniques, we provide mechanistic insight into the mode of action of the FBH1 helicase as a regulator of RAD51-dependent HR in mammalian cells. We show that FBH1 binds directly to RAD51 and is able to disrupt RAD51 filaments on DNA through its ssDNA translocase function. Consistent with this, a mutant mouse embryonic stem cell line with a deletion in the FBH1 helicase domain fails to limit RAD51 chromatin association and shows hyper-recombination. Our data are consistent with FBH1 restraining RAD51 DNA binding under unperturbed growth conditions to prevent unwanted or unscheduled DNA recombination.

Development and certification of green tea-containing standard reference materials

A suite of three green tea-containing Standard Reference Materials (SRMs) has been issued by the National Institute of Standards and Technology (NIST): SRM 3254 Camellia sinensis (Green Tea) Leaves, SRM 3255 Camellia sinensis (Green Tea) Extract, and SRM 3256 Green Tea-Containing Solid Oral Dosage Form. The materials are characterized for catechins, xanthine alkaloids, theanine, and toxic elements. As many as five methods were used in assigning certified and reference values to the constituents, with measurements carried out at NIST and at collaborating laboratories. The materials are intended for use in the development and validation of new analytical methods, and for use as control materials as a component in the support of claims of metrological traceability.

Continuous low-dose cyclophosphamide and methotrexate combined with celecoxib for patients with advanced cancer

BACKGROUND

Combined therapy of metronomic cyclophosphamide, methotrexate and high-dose celecoxib targeting angiogenesis was used in a phase II trial.

METHODS

Patients with advanced cancer received oral cyclophosphamide 50 mg o.d., celecoxib 400 mg b.d. and methotrexate 2.5 mg b.d. for two consecutive days each week. Response was determined every 8 weeks; toxicity was evaluated according to CTC version 2.0. Plasma markers of inflammation, coagulation and angiogenesis were measured.

RESULTS

Sixty-seven of 69 patients were evaluable for response. Twenty-three patients had stable disease (SD) after 8 weeks, but there were no objective responses to therapy. Median time to progression was 57 days. There was a low incidence of toxicities. Among plasma markers, levels of tissue factor were higher in the SD group of patients at baseline, and levels of both angiopoietin-1 and matrix metalloproteinase-9 increased in the progressive disease group only. There were no changes in other plasma markers.

CONCLUSION

This metronomic approach has negligible activity in advanced cancer albeit with minimal toxicity. Analysis of plasma markers indicates minimal effects on endothelium in this trial. These data for this particular regimen do not support basic tenets of metronomic chemotherapy, such as the ability to overcome resistant tumours by targeting the endothelium.

Temozolomide in the treatment of solid tumours: current results and rationale for dosing/scheduling

This review examines the current evidence for the use of temozolomide in the treatment of solid tumours. The possible molecular and clinical advantages of temozolomide are identified and the molecular mechanism of temozolomide resistance is explored. Attempts to maximise efficacy have led to manipulation of both dosage and drug scheduling and the evidence for the various strategies is reviewed. Finally, the potential role of combination therapy is considered.

Changes in amylin and amylin-like peptide concentrations and beta-cell function in response to sulfonylurea or insulin therapy in NIDDM

OBJECTIVE

Amylin, a secretory peptide of beta-cells, is the constituent peptide of islet amyloid, which is characteristic of NIDDM, and changes in amylin secretion in response to therapies may influence the rate of production of islet amyloid. The primary objective of this study was to determine whether therapy with sulfonylurea or basal insulin in NIDDM would alter amylin secretion in a way that might affect the formation of islet amyloid.

RESEARCH DESIGN AND METHODS

In a randomized crossover design, eight subjects with NIDDM underwent three 8-week periods of therapy with diet alone, sulfonylurea, or exogenous basal insulin, with evaluation of amylin, amylin-like peptide (ALP), and glucose and C-peptide concentrations, both during fasting and after a standard breakfast. Changes in beta-cell function (% beta) were assessed, in the basal state by homeostasis model assessment (HOMA) and in the stimulated state by hyperglycemic clamps. Seven nondiabetic control subjects each underwent a meal profile and hyperglycemic clamp.

RESULTS

Both sulfonylurea and insulin therapy reduced basal glucose concentrations compared with diet alone, but neither reduced the increased postprandial glucose increments. Both sulfonylurea and insulin therapy increased basal % beta, assessed by HOMA, but only sulfonylurea increased the second-phase C-peptide responses to the hyperglycemic clamp. Sulfonylurea increased time-averaged mean postprandial amylin and ALP concentrations compared with diet alone (geometric mean [1-SD range] for amylin, 4.9 [2.0-11.8] vs. 3.0 [1.4-6.2] pmol/l, P = 0.003; for ALP, 16.4 [8.5-31.7] vs. 10.1 [4.9-20.8] pmol/l, P = 0.001). Insulin therapy reduced basal ALP concentrations compared with diet alone (2.9 [1.5-5.6] vs. 6.0 [2.6-13.6] pmol/l, P = 0.03), but had no effect on postprandial concentrations of amylin (3.0 [1.3-6.5] pmol/l) or ALP (10.0 [5.5-18.1] pmol/l).

CONCLUSIONS

By increasing postprandial concentrations of the constituent peptides of islet amyloid, sulfonylurea therapy might increase the rate of deposition of islet amyloid and thereby accelerate the decline of % beta in NIDDM, compared with diet therapy alone.

Rapid physicochemical detachment, separation and concentration of bacteria from beef surfaces

A simple, rapid, physicochemical treatment for the removal of viable bacteria from the surface of raw and cooked beef is described. The detachment method was linked to a differential centrifugation step which removed large amounts of particulate food matter and concentrated the detached bacteria. The method increased the numbers of bacteria released from beef surfaces and increased the numbers detected by at least one and a half orders of magnitude, when compared to the traditional 'stomaching' technique. This 1-h separation and concentration method produced cleaner suspensions of bacteria and improved the sensitivity of detection by DEFT and direct plate count.

Resistance of melanoma cell lines to interferons correlates with reduction of IFN-induced tyrosine phosphorylation. Induction of the anti-viral state by IFN is prevented by tyrosine kinase inhibitors

Clinical and experimental studies examining the action of IFNs on human malignant melanomas and melanoma cell lines have shown that this cancer cell type is frequently IFN resistant. In the present study, the IFN responsiveness of five melanoma cell lines, SK-MEL-28, SK-MEL-3, MM96, HT-144, and Hs 294T, as determined by the levels of IFN-induced expression of the antiviral proteins, 100 kDa 2',5'-oligoadenylate synthetase (OAS) and Mx Ag, was shown to correlate with the IFN responsiveness of the five lines measured in antiproliferative and antiviral assays. Three of the lines, SK-MEL-28 (IFN sensitive), SK-MEL-3 (moderately IFN sensitive), and MM96 (IFN insensitive) were analyzed further to ascertain their relative levels of IFN-activated signal transduction. Pretreatment of the three melanoma cell lines with the tyrosine kinase inhibitors, Herbimycin A or Genistein, produced a dose-dependent inhibition of the antiviral action of IFN-alpha, -beta, and -gamma and the induction of OAS by IFN-beta. Thus, induction of the antiviral state in melanoma cells by IFN requires activation of tyrosine kinase-dependent signaling pathways. Furthermore, the IFN responsiveness of three melanoma cell lines could be correlated with the ability to detect by immunoblotting of SDS-PAGE displays of cell lysates, IFN-induced tyrosine phosphorylated cellular proteins in the range m.w. 80 to 130 kDa. This induction was also sensitive to the tyrosine kinase inhibitors Herbimycin A and Genistein. Based on these results, we propose that the IFN-resistant melanoma cell lines examined contain a deficiency early in the IFN signal transduction pathway resulting in a reduced potential for IFN-induced tyrosine phosphorylation and a lack of responsiveness to IFN.

Resistance of melanoma cell lines to interferons correlates with reduction of IFN-induced tyrosine phosphorylation. Induction of the anti-viral state by IFN is prevented by tyrosine kinase inhibitors

Clinical and experimental studies examining the action of IFNs on human malignant melanomas and melanoma cell lines have shown that this cancer cell type is frequently IFN resistant. In the present study, the IFN responsiveness of five melanoma cell lines, SK-MEL-28, SK-MEL-3, MM96, HT-144, and Hs 294T, as determined by the levels of IFN-induced expression of the antiviral proteins, 100 kDa 2',5'-oligoadenylate synthetase (OAS) and Mx Ag, was shown to correlate with the IFN responsiveness of the five lines measured in antiproliferative and antiviral assays. Three of the lines, SK-MEL-28 (IFN sensitive), SK-MEL-3 (moderately IFN sensitive), and MM96 (IFN insensitive) were analyzed further to ascertain their relative levels of IFN-activated signal transduction. Pretreatment of the three melanoma cell lines with the tyrosine kinase inhibitors, Herbimycin A or Genistein, produced a dose-dependent inhibition of the antiviral action of IFN-alpha, -beta, and -gamma and the induction of OAS by IFN-beta. Thus, induction of the antiviral state in melanoma cells by IFN requires activation of tyrosine kinase-dependent signaling pathways. Furthermore, the IFN responsiveness of three melanoma cell lines could be correlated with the ability to detect by immunoblotting of SDS-PAGE displays of cell lysates, IFN-induced tyrosine phosphorylated cellular proteins in the range m.w. 80 to 130 kDa. This induction was also sensitive to the tyrosine kinase inhibitors Herbimycin A and Genistein. Based on these results, we propose that the IFN-resistant melanoma cell lines examined contain a deficiency early in the IFN signal transduction pathway resulting in a reduced potential for IFN-induced tyrosine phosphorylation and a lack of responsiveness to IFN.

An evaluation of the local reaction and biodegradation of calcium sodium alginate (Kaltostat) following subcutaneous implantation in the rat

Kaltostat swabs were implanted subcutaneously in rats to evaluate their biodegradability and ability to evoke local tissue reactions. Implant sites were evaluated after 24 h and after 7 days, 28 days and 12 weeks. Histological sections showed no noticeable degradation of the Kaltostat within the 3 month observation period, contrary to some published reports. Following subsidence of a modest foreign body reaction, implants became embedded in thin fibrous sheaths which were infiltrated with vascular channels and fibroblasts. This study demonstrates that Kaltostat fibres are well tolerated following subcutaneous implantation in the rat model and present no obvious toxic risk or contraindication to their use as wound dressings or as haemostatic agents in general surgery.

cDNA sequence identity for the type I interferon receptor subunit from cell lines of widely differing responsiveness to interferon

Melanoma cell lines exhibit strikingly different sensitivity to the antiproliferative effects of interferon. cDNAs encoding the Type I interferon receptor subunit were amplified by polymerase chain reaction, using as template RNA isolated from three melanoma cell lines displaying greater than 100 fold range in their sensitivity to the antiproliferative effects of IFN-beta. Comparison of the cDNA sequences obtained with the published cDNA sequence from the highly interferon-sensitive lymphoid cell line Daudi revealed only one base change that leads to a conservative amino acid substitution. It is concluded that the cellular differences in responsiveness to interferon, of the melanoma cell lines tested, do not arise from the expression of variants of the cloned Type I interferon receptor subunit.

Characterization of a second nuclear gene, AEP1, required for expression of the mitochondrial OLI1 gene in Saccharomyces cerevisiae

Due to mutation in a single nuclear locus, AEP1, the temperature-conditional pet mutant ts1860 of Saccharomyces cerevisiae fails to synthesize mitochondrial ATP synthase subunit 9 at the restrictive temperature of 36 degrees C. The presence at this temperature of near-normal levels of the cognate oli1 mRNA in mutant ts1860 indicates that, as previously shown, the product of the AEP1 gene is required for translation of the mitochondrial oli1 transcript. In this study the AEP1 gene has been cloned from a wild-type yeast genomic library by genetic complementation of a temperature-conditional aep1 strain at the restrictive temperature. A 2,330-bp genomic fragment which restores subunit 9 synthesis in aep1 mutant strains was characterized. This fragment encoded five open reading frames: the longest of these, at 1,554 nucleotides, was identified as the AEP1 gene, since disruption of this reading frame generated a non-conditional pet strain unable to synthesize subunit 9. The predicted product of AEP1 is a basic, hydrophilic protein of 59,571 Da which possesses a putative mitochondrial address sequence. Hybridization studies with AEP1-specific probes indicate that the gene is located on chromosome XIII and produces several poly(A)+ transcripts ranging in size from 0.9 to 2.7 kb. None of the identified reading frames share significant homologies with entries of several data bases.

Use of the polymerase chain reaction and 16S rRNA sequences for the rapid detection of Brochothrix spp. in foods

Oligonucleotide primers were designed against rRNA sequences to give a DNA-based PCR assay for the rapid identification/detection of Brochothrix spp. The PCR products could be confirmed by hybridization to an internal oligonucleotide probe. The method successfully and sensitively detected/identified these organisms in pure cultures but was of limited value as a detection method because the detection sensitivity, in relation to conventional plate counts, varied and the assay sensitivity was reduced in the presence of staphylococci. Furthermore, sensitivity was also lost when the assay was applied directly to meat samples. However, a separation step using a lectin (from Agaricus bisporus) immobilized on magnetic beads prior to the PCR assay, allowed the direct detection of low numbers (> 10(2) cfu g-1) of Brochothrix in meat samples within a working day.

Separation of bacteria using agglutinins isolated from invertebrates

The agglutination of a selection of Gram-positive and Gram-negative bacteria by the haemolymph and coelomic fluid from several invertebrates was studied. The haemolymph from Lumbricus terrestris and Limulus polyphemus caused the strongest agglutination of most of the bacteria studied. When the agglutinating fraction of Lim. Polyphemus was liganded to magnetic microspheres 53% of the cells in pure cultures of Listeria monocytogenes C200, 15% of Salmonella enteritidis 37782, 92% of Staphylococcus aureus NCDO 949, 19% of Escherichia coli E4936/76 and 65% of E. coli W2-2 were adsorbed to the beads. The immobilized haemolymph from Lumb. terrestris adsorbed 42% of Salm. enteritidis 37782, 64% of E. coli 4936/76 and 27% of Staph. aureus NCDO 1499 cells and the coelomic fluid from Haemopsis sanguisuga adsorbed 42, 48 and 50% of these cultures respectively. With immobilized Haem. sanguisuga agglutinins, 21-27% of Staph. aureus NCDO 2044 cells were recovered from full-fat pasteurized milk and 20-51% from braising steak. Immobilized Lim. polyphemus agglutinins recovered 17-34% of Staph. aureus cells from raw egg. The potential of agglutinins isolated from invertebrates for enhancing rapid microbiological assays of foods is discussed.

Evidence for an [Fe]-type hydrogenase in the parasitic protozoan Trichomonas vaginalis

The hydrogenase of the pathogenic protozoan Trichomonas vaginalis was extracted and partially purified. The catalytic and spectroscopic properties of the enzyme indicate that it belongs to the class of [Fe]-hydrogenases, rather than the [NiFe]-hydrogenases. The hydrogenase activity was highly sensitive to carbon monoxide, 50% inhibition being attained by 1 microM CO. The EPR spectrum of the most active fractions from chromatography, after reduction by hydrogen and partial reoxidation under argon, showed an EPR spectrum at g = 2.10, 2.04, 2.00. This unusual spectrum is characteristic of the 'H-cluster', as seen in [Fe]-hydrogenases of anaerobic bacteria such as Clostridium spp.

Immunoreactive prostaglandin G/H synthase content increases in ovine cotyledons during late gestation

In this study, using gel electrophoresis and Western blotting, we have demonstrated that the content of irPGHS in ovine placenta increases during late gestation prior to the onset of labour. This increase in PGHS tissue content may contribute to the corresponding increased production of prostaglandins by the ovine placenta during this period of pregnancy. Although the mechanism by which PGHS tissue content is elevated at this time remains to be established, one possibility which is currently being investigated in our laboratory is that increased PGHS content reflects an increased level of PGHS gene expression.

The use of immobilized lectins in the separation of Staphylococcus aureus, Escherichia coli, Listeria and Salmonella spp. from pure cultures and foods

Lectins from Helix pomatia, Canavalia ensiformis, Agaricus bisporus and Triticum vulgaris agglutinated cultures of Staphylococcus aureus, Escherichia coli, Listeria and Salmonella spp. This agglutination was specific as it was inhibited (except with A. bisporus lectin) by the competing sugar substrates. The ability of three of these lectins, immobilized on a variety of supports, to separate these micro-organisms from pure cultures was investigated. Immobilization of the lectins on magnetic microspheres was the most effective method. Immobilized T. vulgaris lectin bound 87-100% of cells from cultures of L. monocytogenes, 80-100% of Staph. aureus, 33-45% of Salmonella spp. and 42-77% of E. coli. The A. bisporus lectin bound 31-63% of cells in cultures of L. monocytogenes, 83% of Staph. aureus but only 3-5% of the salmonella cells. Similarly H. pomatia lectin bound greater than 92% of Staph. aureus and 64% of L. monocytogenes cells but was poor at binding the Gram-negative organisms. This preference for binding Gram-positive organisms was confirmed when mixed cultures were studied. The T. vulgaris lectin was effective in removing L. monocytogenes (43%) and Staph. aureus (26%) from diluted milk and Salmonella (31-54%) from raw egg. Agaricus bisporus lectin removed L. monocytogenes from undiluted milk (10-47%) or ground beef (32-50%).

Haematometra in the Langer-Giedion syndrome

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Characterization of a yeast nuclear gene, AEP2, required for accumulation of mitochondrial mRNA encoding subunit 9 of the ATP synthase

The temperature-conditional pet mutant, ts379, of Saccharomyces cerevisiae fails to synthesize mitochondrial ATP synthase subunit 9 at the restrictive temperature due to mutation of a single nuclear locus, AEP2. The inability to synthesize subunit 9 correlates with a lowered accumulation of the cognate oli1 mRNA indicating that the AEP2 product is involved in oli1 transcript maturation or stabilization. The AEP2 gene has been isolated in this study from a wild-type yeast genomic library by genetic complementation of ts379 at the restrictive temperature. A 1,740 nucleotide open-reading frame was observed that encodes a basic, hydrophilic protein of 67,534 Da which possesses a putative mitochondrial address signal. Disruption of chromosomal DNA within this reading frame produced a non-conditional respiratory mutant unable to synthesize subunit 9, identifying the AEP2 gene. Hybridization analyses indicate that AEP2 is located on chromosome XIII and produces a 2.1 kb poly(A)+ transcript. Two additional open-reading frames were found in close proximity to that of AEP2. The three open-reading frames shared no significant homology with entries in several data bases.

Properties of two nuclear pet mutants affecting expression of the mitochondrial oli1 gene of Saccharomyces cerevisiae

This study details the characteristics of two temperature-conditional pet mutants of yeast, strains ts1860 and ts379, which at the non-permissive temperature show deficiencies in the formation of three mitochondrially encoded subunits of the ATP synthase complex. By analysis of mitochondrial translation products, and of mitochondrial transcription in temperature shift experiments from the permissive (22 degrees C) to the non-permissive (36 degrees C) temperature, it was concluded that the nuclear mutations in both mutants primarily inhibit synthesis of ATP synthase subunit 9, and that reductions in subunit 8 and 6 synthesis are secondary pleiotropic effects. Following transfer to 36 degrees C, cells of mutant ts379 display a near complete inhibition of subunit 9 synthesis within 1 h, coincident with a marked reduction in the level of the cognate oli1 mRNA. On the other hand, near complete inhibition of subunit 9 synthesis in strain ts1860 occurs after 3 h at 36 degrees C, at which time there is little change in the level of subunit 9 mRNA. In both mutants the mRNA levels for subunits 6 and 8 are not significantly affected at the time of inhibition of subunit 9 synthesis. Provision of an alternative source of subunit 8, translated extra-mitochondrially for import into the organelle, does not overcome the mutant phenotype of either mutant at 36 degrees C, confirming that subunit 8 is not the sole or primary deficiency in each mutant. The mutants indicate that the products of a least two nuclear genes (designated AEP1 and AEP2) are required for the expression of the mitochondrial oli1 gene and the synthesis of subunit 9. (ABSTRACT TRUNCATED AT 250 WORDS)

Is the diagnosis of spontaneous rupture of a normal spleen valid?

Since Atkinson first described idiopathic rupture of a normal spleen in 1874, there has been controversy regarding the application of the terms "idiopathic" and "spontaneous". One such case is reported, and the validity of the description "idiopathic" or "spontaneous" discussed.

Electron paramagnetic resonance spectroscopic investigation of the inhibition of the phosphoroclastic system of Clostridium sporogenes by nitrite

The proposal that nitrite exerts its inhibitory effect on anaerobic bacteria by direct interaction with the iron-sulphur proteins of the phosphoroclastic system was investigated. The effects of nitrate, nitrite with or without ascorbate, and nitric oxide on the growth of Clostridium sporogenes in liquid cultures at pH 7.4, on the rates of hydrogen production, and on the activities of the enzymes pyruvate-ferredoxin oxidoreductase and hydrogenase, and of ferredoxin were investigated. In agreement with previous studies, nitrate was the least effective inhibitor of cell growth, and nitric oxide the most effective. Nitrite reductase activity was very low in C. sporogenes, indicating that the presence of external reducing agents would be necessary for the reduction of nitrite to nitric oxide. Inhibition by nitrite was enhanced by ascorbate; 0.5 mM-nitrite with 10 mM-ascorbate stopped growth completely. In partially-purified preparations 4.1 mM-NaNO2 and equimolar ascorbate caused complete inactivation of hydrogenase activity but only partial (up to 78%) inactivation of pyruvate-ferredoxin oxidoreductase. This agreed with the loss of hydrogen production observed with nitrite in vivo. Inhibition occurred within 5 min, and was irreversible in each case. Electron paramagnetic resonance (EPR) spectroscopy showed that paramagnetic [Fe(NO)2(SR)2] species were formed during growth in the presence of nitrite, and were associated with cells. However, the intensity of these EPR signals did not correlate with the inhibition of cell growth. The [4Fe-4S] clusters in ferredoxin were shown by EPR spectroscopy to be resistant to treatment with 3.6 mM-NaNO2 and 3.6 mM-ascorbate. It is concluded that the effects of nitrite on pre-formed iron-sulphur proteins are not convincing as a basis for the lethal effects on bacterial cells.

Interactions of iron-thiol-nitrosyl compounds with the phosphoroclastic system of Clostridium sporogenes

Certain reagents, such as ascorbate or iron salts and thiols, enhance the bacteriostatic action of nitrite on food-spoilage bacteria. This may be due to the formation of nitric oxide and iron-thiol-nitrosyl [( Fe-S-NO]) complexes. The minimum concentrations of these reagents required to inhibit growth of Clostridium sporogenes were investigated. A mixture of nitrite (0.72 mM) with iron (1.44 mM) and cysteine (2.16 mM) was found to be extremely inhibitory when autoclaved and diluted into the culture medium. This mixture caused rapid cessation of growth and loss of cell viability at a final concentration corresponding to 40 microM-nitrite. If added to the initial culture medium, it prevented growth at 5 microM-nitrite. The mixture was more inhibitory, on the basis of the nitrite concentration used, than the 'Perigo factor', obtained by autoclaving nitrite in growth medium. [Fe-S-NO] compounds of known chemical structure were tested to determine if they were responsible for this effect. Total inhibition of cell growth was observed with the tetranuclear clusters [Fe4S3(NO)7] (Roussin's black salt), [Fe4S4(NO)4] or [Fe4Se3(NO)7], added at concentrations equivalent to 10 microM-nitrite, or with [Fe2(SMe)2(NO)4] (methyl ester of Roussin's red salt), equivalent to 200 microM-nitrite. The rate of hydrogen production in growing cell cultures was inhibited by [Fe4S3(NO)7] at levels equivalent to 2.5 microM-nitrite. EPR spectra of the inhibited cells showed features with g-values of 2.03, characteristic of mononuclear iron-nitrosyl species, and, under non-reducing conditions, an unusual signal at g = 1.65. There was no correlation between growth inhibition and the g = 2.03 signal, though there was a better correlation between inhibition and the g = 1.65 signal. The direct effects of the compounds were tested on the iron-sulphur proteins of the phosphoroclastic system, namely ferredoxin, pyruvate-ferredoxin oxidoreductase and hydrogenase. EPR spectra and enzyme assays showed that these proteins were not destroyed by [Fe4S3(NO)7], [Fe4S4(NO)4], [Fe2(SMe)2(NO)4], [Fe(SPh)2(NO)2], or M2 (an autoclaved mixture of 66 mM-cysteine, 3.6 mM-FeSO4 and 0.72 mM-NaNO2) at concentrations higher than those that caused total inhibition of cell growth. Inhibition of cells by [Fe-S-NO] compounds is unlikely to be due to interaction with the preformed enzymes. The possible formation of iron-nitrosyl complexes in vivo, and their inhibitory actions, are discussed.

Sexual functioning as a topic in occupational therapy training: a survey of programs

To investigate the current status of sex education in occupational therapy curricula, a questionnaire survey was mailed to department chairs of 67 university programs that were either accredited or in the application process. A total of 50 programs returned usable responses. The results indicate that occupational therapy may be in a transition period: A significant minority of the respondents were either undecided about or against including sexual functioning in occupational therapy, but the majority were of the opinion that the patient's sexual functioning is an important domain of occupational therapy practice. A high percentage of programs reported that instructional time was being devoted to the basics of sexual functioning, but programs varied considerably in the amount of time allocated for this topic.

Rupture of angiomyolipoma of the kidney presenting as puerperal collapse

We report an unusual presentation of angiomyolipoma of the kidney. Whilst a conservative surgical approach is ideal, the greatly increased cardiac output in pregnancy makes haemorrhage more severe and hence more radical surgery is often required. The difficulty in reaching a correct pre-operative diagnosis can lead to an unusual approach to nephrectomy, of which the surgeon should be forewarned.

Quality assurance of histopathologic diagnosis in the British Army: role of the Army Histopathology Registry in completed case review

The purpose of this study was to assess the clinical and pathological value of reports resulting from review of all completed surgical pathology cases submitted to the Army Histopathology Registry (AHR). All histopathological cases completed in the British Army are sent to the AHR for archiving; prior to placing cases in the archive both microscopic material and submitted reports are reviewed by staff of the AHR. A "nonagreed" report is produced for those cases in which the reviewing pathologist has a dissenting opinion or for which he thinks other comments may be helpful. All nonagreed reports produced over a 19 month period were subjected to a further pathological and clinical review. The original surgical pathology reports were compared with AHR reports and the significance of the differences in diagnosis assessed. During the study interval, 4.0% of total cases reviewed were identified as nonagreed record cases. The clinical and pathological reviews placed the nonagreed cases into significant categories in 2.1% and 1.9% of instances respectively. These findings suggest that nonselected review of completed surgical pathology cases identifies a significant proportion of cases for which dissenting opinions may have important clinical and pathological consequences.

The helminth parasites of the sheathbill, Chionis alba (Gmelin), and the diving petrels, Pelecanoides georgicus (Murphy and Harper) and P. urinatrix (Gmelin), at Bird Island, South Georgia

Twelve sheathbills, Chionis alba, 12 South Georgian diving petrels, Pelecanoides georgicus, and 5 common diving petrels, P. urinatrix, collected at Bird Island, South Georgia, were examined for helminth parasites. These appear to be the first helminthological examinations of birds from South Georgia. Eleven of the 12 sheathbills were infected with helminth parasites and the pattern of infection of adult male and female birds was similar. Five species of helminths were found in sheathbills, namely Gymnophallus dellciosus, Notocotylus chionis, Paramonostomum signiensis, Lateriporus australis and Corynosoma hammani. Two species, namely Tetrabothrius sp. and Stegophorus heardi, were found in both Pelecanoides georgicus and P. urinatrix.

The helminth parasites of whales and seals in the Antarctic and Subantarctic have been extensively studied, while in comparison those of birds from these regions have been neglected. As far as we are aware there are no previous reports on helminth parasites from the sheathbill, Chionis alba (Gmelin), the South Georgian diving petrel, Pelecanoides georgicus (Murphy and Harper), and the common diving petrel, P. urinatrix (Gmelin), from South Georgia.