Gerstmann-Sträussler-Scheinker Disease Presenting as Late-Onset Slowly Progressive Spinocerebellar Ataxia, and Comparative Case Series with Neuropathology

BACKGROUND

Genetic prion diseases, including Gerstmann-Sträussler-Scheinker disease (GSS), are extremely rare, fatal neurodegenerative disorders, often associated with progressive ataxia and cognitive/neuropsychiatric symptoms. GSS typically presents as a rapidly progressive cerebellar ataxia, associated with cognitive decline. Late-onset cases are rare.

OBJECTIVE

To compare a novel GSS phenotype with six other cases and present pathological findings from a single case.

METHODS

Case series of seven GSS patients, one proceeding to autopsy.

RESULTS

Case 1 developed slowly progressive gait difficulties at age 71, mimicking a spinocerebellar ataxia, with a family history of balance problems in old age. Genome sequencing revealed a heterozygous c.392G > A (p.G131E) pathogenic variant and a c.395A > G resulting in p.129 M/V polymorphism in the PRNP gene. Probability analyses considering family history, phenotype, and a similar previously reported point mutation (p.G131V) suggest p.G131E as a new pathogenic variant. Clinical features and imaging of this case are compared with those six additional cases harboring p.P102L mutations. Autopsy findings of a case are described and were consistent with the prion pathology of GSS.

CONCLUSIONS

We describe a patient with GSS with a novel p.G131E mutation in the PRNP gene, presenting with a late-onset, slowly progressive phenotype, mimicking a spinocerebellar ataxia, and six additional cases with the typical P102L mutation.

An exploration of nematode assemblages in the hydroponic media beds of a commercial aquaponics system

Nematodes perform important ecosystem services in soils and are well studied in traditional farming, but their role in newer soil-less food production systems is unstudied. We determined the nematode assemblages from substrates within the hydroponic media beds of a commercial aquaponics system. Three substrates were studied: coir, compost and lightweight expanded clay aggregate (LECA), with the nematode assemblages ascertained via traditional morphological analysis. All substrates were suitable for nematodes but abundance was lower compared with traditional compost. Compost from within the hydroponic media beds had nematode assemblages with similar maturity indices (MI) to compost external to the system, and both composts housed nematodes with a high proportion of bacterivores, a high degree of enrichment and no structure. LECA that were regularly disturbed and had little organic build up resembled compost – highly enriched and lacking structure. LECA that had been left undisturbed for longer and allowed to accumulate more organic matter had highly structured assemblages and showed less enrichment than the other substrates. Nematode assemblages within the coir showed very little enrichment but had higher MI and were more structured than compost. Problematic plant-parasitic nematodes were not found in any of the samples. We present the first glimpse into the role of nematodes in aquaponics systems and encourage future studies to explore how nematodes in these systems affect yield and plant health.

A novel, immunotherapy-based approach for the treatment of relapsed/refractory multiple myeloma (RRMM): Updated phase 1b results for daratumumab in combination with teclistamab (a BCMA x CD3 bispecific antibody)

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Background: Teclistamab (tec; JNJ-64007957) is a BCMA × CD3 T-cell redirecting bispecific antibody under investigation in patients (pts) with RRMM. Daratumumab (dara) is a CD38 mAb with direct on-tumor and immunomodulatory actions. Initial clinical data from the phase 1b multicohort TRIMM-2 study support the combination of tec + dara for the treatment of RRMM, with tolerable safety, no overlapping toxicities, and promising efficacy. We present updated results with additional pts and longer follow-up. Methods: Eligible MM pts aged ≥18 y had received ≥3 prior lines of therapy (LOT; including a proteosome inhibitor [PI] and immunomodulatory drug [IMiD]) or were double-refractory to a PI and IMiD. Pts treated with anti-CD38 therapy ≤90 d prior were excluded. Pts received dara SC 1800 mg per approved schedule and tec SC 1.5–3 mg/kg QW or Q2W. Primary objectives were to identify the recommended phase 2 dose of tec for combination therapy and evaluate safety of the combination. Responses were assessed by IMWG criteria. AEs were graded per CTCAE v5.0; cytokine release syndrome (CRS) and immune effector cell–associated neurotoxicity syndrome (ICANS) were graded per ASTCT guidelines. Results: At data cutoff (Jan 13, 2022; safety population: N=46), median follow-up was 7.2 mo (range 0.1–16.6; median age 67 y [range 50–79]; 52% female). Pts received a median of 6 prior LOT (range 2–17; 74% triple-class exposed; 63% penta-drug exposed; 15% anti-BCMA exposed). 91% of pts had ≥1 AE (grade 3/4 78%), most commonly CRS (61%; all grade 1/2; median time to onset 2 d; median duration 2 d), neutropenia (54%; grade 3/4 50%), anemia (46%; grade 3/4 28%), thrombocytopenia (33%; grade 3/4 28%), and diarrhea (33%; grade 3/4 2%). Infections occurred in 29 pts (63%; grade 3/4 28%). One pt had grade 1 ICANS that fully resolved. Among 37 response-evaluable pts, ORR was 78% (29/37); 27 pts (73%) had very good partial response (VGPR) or better (Table). Median time to first response across dosing cohorts was 1.0 mo (range 0.9–2.8); median duration of response was not reached. Upregulation of CD38+/CD8+ T cells and proinflammatory cytokines was observed with tec + dara, supporting potential synergy of the combination in pts with prior anti-CD38 exposure. Updated results will be presented. Conclusions: Tec + dara provides a novel immunotherapy approach for the treatment of RRMM that may yield improved clinical efficacy in heavily pretreated pts. Clinical trial information: NCT04108195. [Table: see text]

Updated results of a phase 1, first-in-human study of talquetamab, a G protein-coupled receptor family C group 5 member D (GPRC5D) × CD3 bispecific antibody, in relapsed/refractory multiple myeloma (MM)

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Background: New immunotherapy targets in MM are needed as patients (pts) continue to relapse. The orphan receptor GPRC5D is expressed on malignant plasma cells in MM. Talquetamab (JNJ-64407564) is a bispecific IgG4 antibody that redirects T cell killing to MM cells by binding to the novel target, GPRC5D, and CD3. We present updated results of talquetamab at the recommended phase 2 dose (RP2D) from a phase 1 trial in relapsed/refractory MM. Methods: Eligible pts with MM who had relapsed or refractory disease or were intolerant to standard therapies received talquetamab intravenously (IV; range 0.5–180 µg/kg) or subcutaneously (SC; range 5.0–800 µg/kg) weekly or biweekly. Primary objectives were identification of the RP2D (part 1) and talquetamab safety and tolerability at the RP2D (part 2). Adverse events (AEs) were graded by CTCAE v4.03 (cytokine release syndrome [CRS] per Lee 2014). Response was assessed per IMWG criteria. Results: As of Feb 8, 2021, 174 pts received talquetamab, 102 by IV and 72 by SC; in parts 1 and 2, 28 pts were treated at the RP2D, identified as weekly SC 405 µg/kg, with 10.0 and 60.0 µg/kg step-up doses. Pts treated at the RP2D had a median age of 61.5 y (range 46–80) and a median of 5.5 prior lines of therapy (range 2–14; 100%/79% triple-class/penta-drug exposed; 71%/18% triple-class/penta-drug refractory; 86% refractory to last line of therapy; 21% with prior B-cell maturation antigen–directed therapy). No dose-limiting toxicities occurred at the RP2D in part 1. Most common AEs at the RP2D were CRS (79%; grade 3 4%; median time to onset: day after SC injection), neutropenia (64%; grade 3/4 54%), anemia (57%; grade 3/4 29%) and dysgeusia (57%; all grade 1/2); infections were reported in 32% of pts (grade 3/4 4%) and neurotoxicity in 7% (grade 3/4 0). In all, 75% of pts dosed at the RP2D had skin-related AEs (grade 3/4 0), including 18% with nail disorders. The overall response rate at the RP2D in response-evaluable pts (n = 24) was 63%, with 50% reaching very good partial response or better; 9/17 (53%) evaluable triple-class refractory pts and 3/3 (100%) penta-drug refractory pts had a response. Median time to first confirmed response at the RP2D was 1.0 mo (range 0.2–3.8); responses were durable and deepened over time (median follow-up 6.2 mo [range 2.7–9.7+] for responders at the RP2D). At the RP2D, exposure was maintained over the maximum EC90 target level from an ex vivo cytotoxicity assay, and consistent T cell activation was seen. Conclusions: At the RP2D of weekly 405 µg/kg SC, talquetamab showed a high clinical response rate and was well-tolerated in pts with relapsed/refractory MM; based on pharmacokinetic data, other SC dosing strategies are being explored. The promising efficacy, safety profile and convenience of SC dosing support monotherapy development and combination approaches with this novel agent. Clinical trial information: NCT03399799.

Metabarcoding of soil nematodes: the importance of taxonomic coverage and availability of reference sequences in choosing suitable marker(s)

For many organisms, there is agreement on the specific genomic region used for developing barcode markers. With nematodes, however, it has been found that the COI region designated for most animals lacks the taxonomic coverage (ability to amplify a diverse group of taxa) required of a metabarcoding marker. For that reason, studies on metabarcoding of nematodes thus far have utilized primarily regions within the highly conserved 18S ribosomal DNA. Two popular markers within this region are the ones flanked by the primer pairs NF1-18Sr2b and SSUF04-SSUR22. The NF1-18Sr2b primer pair, especially, has been critiqued as not being specific enough for nematodes leading to suggestions for other candidate markers while the SSUF04-SSUR22 region has hardly been tested on soil nematodes. The current study aimed to evaluate these two markers against other alternative ones within the 28S rDNA and the COI region for their suitability for nematode metabarcoding. The results showed that the NF1-18Sr2b marker could offer wide coverage and good resolution for characterizing soil nematodes. Sufficient availability of reference sequences for this region was found to be a significant factor that resulted in this marker outperforming the other markers, particularly the 18S-based SSUFO4-SSUR22 marker. None of the other tested regions compared with this marker in terms of the proportion of the taxa recovered. The COI-based marker had the lowest number of taxa recovered, and this was due to the poor performance of its primers and the insufficient number of reference sequences in public databases. In summary, this study highlights how dependent the success of metabarcoding is on the availability of a good reference sequence collection for the marker of choice as well as its taxonomic coverage.

Fetal abdominal cysts: antenatal course and postnatal outcomes

Background There is little information on which to base the prognostic counselling as to whether an antenatally diagnosed fetal abdominal cyst will grow or shrink, or need surgery. This study aims to provide contemporary data on prenatally diagnosed fetal abdominal cysts in relation to their course and postnatal outcomes. Methods Fetal abdominal cysts diagnosed over 11 years in a single centre were identified. The gestational age at diagnosis and cyst characteristics at each examination were recorded (size, location, echogenity, septation and vascularity) and follow-up data from postnatal visits were collected. Results Eighty abdominal cysts were identified antenatally at 28+4 weeks (range 11+0-38+3). Most (87%) were isolated and the majority were pelvic (52%), simple (87.5%) and avascular (100%). Antenatally, 29% resolved spontaneously; 29% reduced in size; 9% were stable and 33% increased in size. Forty-one percent of cysts under 20 mm diameter increased in size, while only 20% of cysts with a diameter of over 40 mm increased in size. The majority of cysts were ovarian in origin (n=45, 56%), followed by intestinal (n=15, 18%), choledochal (n=3, 4%), liver (n=2, 3%) and renal/adrenal origins (n=2, 3%), respectively. In 16% (n=13), the antenatal diagnosis was not obvious. Seventy-five percent of the cysts that persisted postnatally required surgical intervention. Conclusion Most antenatally diagnosed fetal abdominal cysts were ovarian in origin. Though most disappeared antenatally, nearly three quarters required surgical intervention when present after birth. Cysts of intestinal origin are more difficult to diagnose antenatally and often require surgery.

The impact of cross-border IVF on maternal and neonatal outcomes in multiple pregnancies: Experience from a UK fetal medicine service

OBJECTIVES

To determine whether women seeking NHS care for IVF multiple pregnancies were more likely to have sought IVF treatment overseas and whether this was associated with different maternal and neonatal outcomes.

STUDY DESIGN

A single large tertiary centre, for perinatal care in northwest London. Sixty-five women were referred to our fetal medicine centre, between 2012-2016, with IVF conceived multiple pregnancies.

INCLUSION CRITERIA

In Vitro fertilisation and conception of twins/ triplets/quadruplets.

EXCLUSION CRITERIA

Intra-uterine insemination, ovulation induction, Clomid-conception and singleton pregnancies. The primary outcome measure was the Country where IVF treatment was performed. The secondary outcomes measures included the specifics of IVF treatment (e.g. number of embryos transferred), subsequent pregnancy outcomes (e.g. live-births and prematurity) and neonatal outcomes (e.g. length and cost of care).

RESULTS AND CONCLUSION

Thirty-eight women had IVF overseas; they were older and had more pre-existing medical conditions. Eleven pregnancies used donor embryos, of which ten were from overseas treatment. 75% of women treated overseas conceived a triplet or higher order pregnancy compared to fewer than 10% of women who conceived in the UK. Almost half of all women treated overseas had more than two embryos transferred. Overseas IVF pregnancies had poorer obstetric and neonatal outcomes: 24% of live born babies died in the neonatal period compared to 0% in the UK group. The average neonatal costs per baby born from overseas IVF were £20, 600: two-and-a-half times higher than for those whose mothers conceived in the UK. Higher order multiple pregnancies are greatly over-represented by those undergoing IVF in overseas clinics. These are associated with poorer obstetric and neonatal outcomes. Perhaps paradoxically, improving NHS provision of fertility services might improve outcomes for the mother and babies while reducing the long-term burden to both fertility patients and the NHS.

Treatment Algorithm for Infants Diagnosed with Spinal Muscular Atrophy through Newborn Screening

Background:

Spinal muscular atrophy (SMA) is an autosomal recessive disease characterized by the degeneration of alpha motor neurons in the spinal cord, leading to muscular atrophy. SMA is caused by deletions or mutations in the survival motor neuron 1 gene (SMN1). In humans, a nearly identical copy gene, SMN2, is present. Because SMN2 has been shown to decrease disease severity in a dose-dependent manner, SMN2 copy number is predictive of disease severity.

Objective:

To develop a treatment algorithm for SMA-positive infants identified through newborn screening based upon SMN2 copy number.

Methods:

A working group comprised of 15 SMA experts participated in a modified Delphi process, moderated by a neutral third-party expert, to develop treatment guidelines.

Results:

The overarching recommendation is that all infants with two or three copies of SMN2 should receive immediate treatment (n = 13). For those infants in which immediate treatment is not recommended, guidelines were developed that outline the timing and appropriate screens and tests to be used to determine the timing of treatment initiation.

Conclusions:

The identification SMA affected infants via newborn screening presents an unprecedented opportunity for achievement of maximal therapeutic benefit through the administration of treatment pre-symptomatically. The recommendations provided here are intended to help formulate treatment guidelines for infants who test positive during the newborn screening process.

DNA barcoding for biosecurity: case studies from the UK plant protection program

Since its conception, DNA barcoding has seen a rapid uptake within the research community. Nevertheless, as with many new scientific tools, progression towards the point of routine deployment within diagnostic laboratories has been slow. In this paper, we discuss the application of DNA barcoding in the Defra plant health diagnostic laboratories, where DNA barcoding is used primarily for the identification of invertebrate pests. We present a series of case studies that demonstrate the successful application of DNA barcoding but also reveal some potential limitations to expanded use. The regulated plant pest, Bursephalenchus xylophilus, and one of its vectors, Monochamus alternatus, were found in dining chairs. Some traded wood products are potentially high risk, allowing the movement of longhorn beetles; Trichoferus campestris, Leptura quadrifasciata, and Trichoferus holosericeus were found in a wooden cutlery tray, a railway sleeper, and a dining chair, respectively. An outbreak of Meloidogyne fallax was identified in Allium ampeloprasum and in three weed species. Reference sequences for UK native psyllids were generated to enable the development of rapid diagnostics to be used for monitoring following the release of Aphalara itadori as a biological control agent for Fallopia japonica.

Statistical Methods for the Analysis of Discrete Choice Experiments: A Report of the ISPOR Conjoint Analysis Good Research Practices Task Force

Conjoint analysis is a stated-preference survey method that can be used to elicit responses that reveal preferences, priorities, and the relative importance of individual features associated with health care interventions or services. Conjoint analysis methods, particularly discrete choice experiments (DCEs), have been increasingly used to quantify preferences of patients, caregivers, physicians, and other stakeholders. Recent consensus-based guidance on good research practices, including two recent task force reports from the International Society for Pharmacoeconomics and Outcomes Research, has aided in improving the quality of conjoint analyses and DCEs in outcomes research. Nevertheless, uncertainty regarding good research practices for the statistical analysis of data from DCEs persists. There are multiple methods for analyzing DCE data. Understanding the characteristics and appropriate use of different analysis methods is critical to conducting a well-designed DCE study. This report will assist researchers in evaluating and selecting among alternative approaches to conducting statistical analysis of DCE data. We first present a simplistic DCE example and a simple method for using the resulting data. We then present a pedagogical example of a DCE and one of the most common approaches to analyzing data from such a question format-conditional logit. We then describe some common alternative methods for analyzing these data and the strengths and weaknesses of each alternative. We present the ESTIMATE checklist, which includes a list of questions to consider when justifying the choice of analysis method, describing the analysis, and interpreting the results.

Morphological and molecular characterisation of Aphelenchoides besseyi and A. fujianensis (Nematoda: Aphelenchoididae) from rice and forage grass seeds in Brazil

Morphologically similarAphelenchoidesspp. populations extracted from rice and forage grass seeds from different geographical regions in Brazil were morphologically and molecularly characterised. Overall, the populations studied separated into two groups based on morphological and phylogenetic analyses, referred to herein as ‘Group-rice’ and ‘Group-forage’. Bayesian phylogenetic analyses of SSU, LSU and mtCOI regions strongly supported the presence of two dichotomous groups with Group-rice and Group-forage populations genetically similar toA. besseyiandA. fujianensis, respectively. This study reports the presence of a morphologically similar species toA. besseyiassociated with seeds of grasses, but genetically distinct based on three genomic regions, which our results strongly suggest to beA. fujianensis, this being a new geographical record for Brazil. Additional information regarding spicule morphology of maleA. besseyiis also reported.

Are fetuses that fail to achieve their growth potential at increased risk of intrapartum compromise?

OBJECTIVE

The true growth potential of a fetus is difficult to predict but recently a new definition, independent of fetal weight, using cerebroplacental (cerebro-umbilical) ratio (CPR) < 0.6765 multiples of the median (MoM), was reported. We applied this definition to a cohort of low-risk pregnancies recruited prospectively to determine if fetuses with CPR < 0.6765 are at increased risk of developing signs of intrapartum fetal compromise.

METHODS

Recruitment to this prospective observational study took place between March 2011 and March 2014. All women with low-risk singleton pregnancies at term were eligible. Women with known or suspected placental dysfunction were excluded, as were women with fetuses with an estimated fetal weight < 10(th) centile. All participants underwent ultrasound examination prior to active labor (≤ 4 cm cervical dilatation), during which fetal biometry as well as umbilical artery and fetal middle cerebral artery blood flow were assessed. Following delivery, intrapartum and neonatal outcomes were compared between fetuses that had a CPR < 0.6765 MoM and those that had a CPR ≥ 0.6765 MoM.

RESULTS

In total, 775 women were recruited. Fetuses with CPR < 0.6765 MoM were significantly more likely to require Cesarean delivery because of presumed fetal compromise (P < 0.001). These fetuses were also at increased risk of compromise at any time during labor and were less likely to be delivered vaginally, spontaneously or otherwise, than were those with CPR ≥ 0.6765 MoM. CPR < 0.6765 MoM gave a positive predictive value (PPV) for Cesarean delivery because of presumed fetal compromise of 36.7% and a negative predictive value of 88.7%, with a sensitivity of 18% and a specificity of 95.4%.

CONCLUSION

Fetuses that failed to achieve their growth potential (defined as CPR < 0.6765 MoM) were at increased risk of intrapartum compromise and were less likely to be delivered vaginally. However, a low negative predictive value was observed for fetal compromise and further studies are required to support the translation of this technique into clinical practice.

Influence of parity on fetal hemodynamics and amniotic fluid volume at term

OBJECTIVES

Pregnancy complications, particularly those associated with placental dysfunction, occur more frequently in nulliparous than in parous women. This difference may be a consequence of improved trophoblastic invasion and, as a result, improved placental function following previous pregnancy. Placental dysfunction in cases of fetal growth restriction may be identified by ultrasound assessment of fetoplacental hemodynamics and amniotic fluid volume. In this prospective observational study, we investigated whether differences in these measures of placental function exist between nulliparous and parous women, prior to active labor.

METHODS

Over a 2-year period, 456 nulliparous and 152 parous women with uncomplicated singleton pregnancies were recruited to this prospective observational study. Each participant underwent an ultrasound assessment prior to active labor, during which fetal biometry, umbilical artery, middle cerebral artery and umbilical venous Dopplers, as well as amniotic fluid volume, were assessed. All cases were followed up within 48 h of delivery. Ultrasound parameters and intrapartum outcomes were then compared between the nulliparous and parous groups.

RESULTS

Compared with nulliparous women, parous women had significantly higher fetal middle cerebral artery pulsatility index, cerebroplacental ratio and amniotic fluid volume. In nulliparous women, middle cerebral artery flow rate was also significantly higher and represented a greater percentage of umbilical venous flow than was observed in parous women.

CONCLUSION

Prior to the active phase of labor, ultrasound parameters indicative of placental function differ significantly between nulliparous and parous pregnancy, even amongst an uncomplicated, low-risk cohort.

[Pleuroparenchymal fibroelastosis is a new entity which can be mistaken for sarcoidosis]

Pleuroparenchymal fibroelastosis is an idiopathic interstitial pneumonia, recently recognized as a new entity by American Thoracic Society/European Respiratory Society. We present the first Danish cases of pleuroparenchymal fibroelastosis in two young sisters, who had complained of dyspnoea since childhood. Their lung function was reduced at referral (forced expiratory volume in 1st sec.: 36-43%, forced vital capacity: 34-41%, diffusing capacity for carbon monoxide: 35%). High resolution CT showed apical peripheral consolidation, pleural thickening, traction bronchiectasis and enlarged lymph nodes of both patients; compatible with pleuroparenchymal fibroelastosis. Due to low lung function, lung biopsies were not performed.

A new approach to identify species in Xiphinema americanum sensu lato

Four putative species belonging to the X. americanum group are known to transmit American nepoviruses and these nematodes and viruses are listed in European quarantine legislation. Identification of species in this group is therefore of particular importance for phytosanitary purposes, but is problematic because of the similar morphology of the putative species. As part of the Synthesys project BE-TAF 1769, eight collaborative institutions contributed material to Fera for study. Video technology allowed the best records of type material and in conjunction with photographic images created a 'virtual' collection of images that relies less on the deteriorating quality of museum specimens. Revised definitions of lip region and tail shape are considered to be the most stable characters for differentiation. Position of the amphidial aperture, development of the odontostyle collar and some established morphometric characters are considered of limited use although they retain value for latter stages of identification.

An analysis of disease severity based on SMN2 copy number in adults with spinal muscular atrophy

To evaluate the effect of SMN2 copy number on disease severity in spinal muscular atrophy (SMA), we stratified 45 adult SMA patients based on SMN2 copy number (3 vs. 4 copies). Patients with 3 copies had an earlier age of onset and lower spinal muscular atrophy functional rating scale (SMAFRS) scores and were more likely to be non-ambulatory. There was, however, no difference between the groups in quantitative muscle strength or pulmonary function testing. Functional scale may be a more discriminating outcome measure for SMA clinical trials.

Feasibility of screening for Lynch syndrome among patients with colorectal cancer

PURPOSE

Identifying individuals with Lynch syndrome (LS) is highly beneficial. However, it is unclear whether microsatellite instability (MSI) or immunohistochemistry (IHC) should be used as the screening test and whether screening should target all patients with colorectal cancer (CRC) or those in high-risk subgroups.

PATIENTS AND METHODS

MSI testing and IHC for the four mismatch repair proteins was performed on 500 tumors from unselected patients with CRC. If either MSI or IHC was abnormal, complete mutation analysis for the mismatch repair genes was performed.

RESULTS

Among the 500 patients, 18 patients (3.6%) had LS. All 18 patients detected with LS (100%) had MSI-high tumors; 17 (94%) of 18 patients with LS were correctly predicted by IHC. Of the 18 probands, only eight patients (44%) were diagnosed at age younger than 50 years, and only 13 patients (72%) met the revised Bethesda guidelines. When these results were added to data on 1,066 previously studied patients, the entire study cohort (N = 1,566) showed an overall prevalence of 44 of 1,566 patients (2.8%; 95% CI, 2.1% to 3.8%) for LS. For each proband, on average, three additional family members carried MMR mutations.

CONCLUSION

One of every 35 patients with CRC has LS, and each has at least three relatives with LS; all of whom can benefit from increased cancer surveillance. For screening, IHC is almost equally sensitive as MSI, but IHC is more readily available and helps to direct gene testing. Limiting tumor analysis to patients who fulfill Bethesda criteria would fail to identify 28% (or one in four) cases of LS.

Outcomes of radical conformal radiotherapy and concomitant cisplatin chemotherapy for olfactory neuroblastoma—Review of a single centre experience

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Background: Olfactory neuroblastoma is rare with 25 new cases annually in the UK. Cranio-facial resection and post operative radiotherapy is standard treatment. The use of concomitant chemotherapy has not been fully evaluated, although chemo-sensitivity has been demonstrated by retrospective series. This study evaluates the use of radical radiotherapy and concomitant chemotherapy. Methods: Since 1978 more than 70 patients have been seen at the Institute of Otology and Laryngology. Eighteen patients treated with radiotherapy between 1999 and 2005 were reviewed. These were all CT planned and treated with conformal radiotherapy ± cisplatin chemotherapy 100 mg/m2 D 1, 22 and 43. The radiotherapy prescribed dose varied from 50Gy to 62 Gy in 1.8 to 2 Gy fractions, 10 (56%) received 60Gy in 30 fractions. Overall survival, disease free survival and treatment related morbidity were assessed. Results: Seventeen patients were post operative and 1 was neo-adjuvant. Mean age was 46 years (range 20–83) and the majority were Kadish stage C. Of the 17 post-operative patients, 13 (76%) had surgery as primary treatment and 4 (24%) for recurrence. Eight patients (44%) received concomitant chemotherapy. At the time of analysis follow up ranged from 4 months to 72 months (median 17.5, mean 28.2), 16 (88.9%) patients were alive and 14 (77.8%) disease free. Four (22.2%) patients developed recurrence and 2 died of disease. Of the 4 patients with recurrence, 3 did not receive concurrent cisplatin chemotherapy and the fourth patient did not undergo radical surgery. No patients reported deterioration in vision or significant morbidity following treatment. Conclusions: Post operative radiotherapy with concurrent cisplatin chemotherapy is effective and well tolerated in the management of olfactory neuroblastoma. Where concurrent chemotherapy was not given, relapse rates were high. Our results, although immature, suggest disease free survival superior to published data. A prospective multi-centre study to evaluate concomitant treatment schedules is required.

No significant financial relationships to disclose.

Durable molecular remissions with a single cycle of timed sequential consolidation chemotherapy in acute promyelocytic leukemia

In a pilot study to reduce the duration of treatment and potential long-term toxicities, 39 patients with acute promyelocytic leukemia in remission received a single cycle of intensive consolidation therapy, followed by intermittent ATRA maintenance. Consolidation therapy required prolonged hospitalization and was associated with a high incidence of mucositis (43% grade II or greater) and documented infection (45%). No deaths occurred during consolidation. Seven patients have relapsed; all other patients are in molecular remission (median follow-up, 2.75 years). Kaplan-Meier estimate of 3 year disease-free survival is 73% (95% confidence interval 55-91%). The relapse rate (0.06 relapses/patient-year of follow-up) is well within the range of larger published series that administer more prolonged consolidation. One patient has developed secondary myelodysplastic syndrome. These pilot data suggest that decreasing the total duration of consolidation chemotherapy did not compromise disease-free survival for APL patients induced with ATRA/anthracycline and given intermittent ATRA maintenance. However, the toxicity of the consolidation module and the development of secondary myelodysplasia despite decreased total therapy emphasize the need to further improve and refine curative therapy for APL.

Phenotypic differences in cholinergic responses of distal colonic epithelium

The Flinders sensitive line (FSL) rats exhibit an increased cholinergic responsiveness in vivo when compared to their counterparts, the Flinders resistant line (FRL) rats. The functional consequences of this phenotypic difference on colonic mucosal function are not known. We sought to determine whether isolated distal colonic mucosa from the two strains exhibit differential responses to cholinergic agonists. The responses of the distal colonic mucosa from two lines of rats to carbachol were compared by recording changes in short-circuit current. The ion movements associated with these changes were assessed by flux analysis of the radiotracers, 22Na and 36Cl. The anticipated hyper-responsiveness to cholinergic stimulation in FSL rats was not seen. Carbachol responses were significantly enhanced by indomethacin pretreatment only in FRL rats. Tetrodotoxin (TTX) pretreatment significantly reduced responses to carbachol in FSL rats at all concentrations tested, though this was only seen with lower concentrations in FRL rats. Flux analysis indicated that both lines absorbed Na+ and Cl- under basal conditions and that a significant residual flux was present. Stimulation with carbachol led to significant reductions in net Na+ and Cl- fluxes in both lines. The changes in net Na+ and Cl- flux in both lines stem largely from a decrease in mucosal to serosal fluxes of both ions with an increase in serosal to mucosal flux of Cl-. The striking difference is the significant reduction in residual flux seen only in FRL rats. Indomethacin pretreatment abolished the changes in residual flux seen in FRL rats. Thus the responses to carbachol in these rats had at least three components: (a) a direct effect on the transporting colonocyte, (b) an indirect effect mediated by an arachidonic acid metabolite, and (c) another indirect effect involving a neurotransmitter. The relative contributions of each of these components were different in the two lines.

Calcium-stimulated short-circuit currents in the canine proximal colonic epithelium: effects of DK-PGD2, a metabolite of prostaglandin D2

Prostaglandin D2 (PGD2) has marked inhibitory effects on the canine proximal colonic epithelium set up in Ussing chambers. These effects involved a receptor that is pharmacologically distinct from the classical DP, presumably the recently identified CRTH2/DP2 variety. The mechanism underlying these effects was studied using 13,14-dihydro-15-keto-PGD2 (DK-PGD2), a stable metabolite of the parent prostanoid. The metabolite quickly reversed short circuit currents (I(sc)) stimulated by diverse agonists. Greater inhibitory effects were seen with stimulants such as carbachol and cyclopiazonic acid (CPA) rather than with forskolin or protein kinase A activators. Since the same stimulants were differentially affected by removal and replacement of serosal Ca2+, we tested the possibility that the prostanoid inhibited basolateral Ca2+ entry. In the absence of serosal Ca2+, tissues primed with CPA demonstrated concentration-dependent increases in I(sc), to cumulative additions of Ca2+ or Sr2+, though the former was more potent. Cl- removal and pretreatment with bumetanide virtually abolished responses, suggesting that the increase in I(sc) reflected Ca2+ dependent Cl- secretion. Though responses were insensitive to the L-type channel antagonist, verapamil, a marked inhibition was seen in the presence of metal cations (Gd3+, Cd2+, and La3+). Pretreatment with DK-PGD2 inhibited responses to Ca2+ in CPA-primed tissues. Thus, basolateral Ca2+ entry via store-operated Ca2+ channels may be the locus for the inhibitory effects of PGD2 in this tissue. These results could indicate a potential transduction mechanism for the novel DP receptor variously called CRTH2 or DP2.

Sphingosine-1-phosphate stimulates human glioma cell proliferation through Gi-coupled receptors: role of ERK MAP kinase and phosphatidylinositol 3-kinase beta

The regulation of glioma cell proliferation by sphingosine-1-phosphate (S1P) was studied using the human glioblastoma cell line U-373 MG. U-373 MG cells responded mitogenically to nanomolar concentrations of S1P, and express mRNA encoding the S1P receptors S1P1/endothelial differentiation gene (EDG)-1, S1P3/EDG-3 and S1P2/EDG-5. S1P-induced proliferation required extracellular signal-regulated kinase activation and was partially sensitive to pertussis toxin and wortmannin, indicating involvement of a Gi-coupled receptor and phosphatidylinositol 3-kinase. Moreover, S1P1, S1P3 and S1P2 receptors are expressed in the majority of human glioblastomas as determined by reverse transcriptase-polymerase chain reaction analysis. Thus, S1P signaling through EDG receptors may contribute to glioblastoma growth in vivo.

Foods, health claims, and the law: comparisons of the United States and Europe

Government, academia, and the food industry can play a significant role in the identification of healthy foods and ingredients important for weight management and health. The U.S. Food and Drug Administration developed regulations that define specific food categories for weight management and health. These categories include foods for special dietary uses and medical foods. Medical foods are classified for use in specific disease states and require a physician's recommendation and continuous monitoring. The European regulations specify energy-restricted foods as a subcategory of food for particular nutritional uses, which includes infant formula, medical foods, and foods for sports. European standards for energy-restricted diets have been established, leaving little flexibility for change. Three categories exist (i.e., very-low-calorie diets [450 to 800 kcal], low-calorie diets [800 to 1200 kcal], and meal replacements [200 to 400 kcal]). No claims on anticipated weight loss can be made even where significant clinical research has demonstrated long-term efficacy, thereby preventing informed choice management. Dramatic changes in lifestyle (e.g., disruption of the family unit, altered eating occasions, fast foods, and food grazing) have resulted in an epidemic of obesity and chronic disease. Regulating food selection or dietary patterns to limit the epidemic is not realistic. However, stimulating government health agencies and the food industry to increase public awareness through educational programs and regulating the definition of acceptable methods and products can provide an environment for change. A consensus is needed among academia, government, and industry for appropriate food labeling and claims. These actions are needed to help individuals make healthy food selections and maintain a healthy weight. Public health initiatives should change consumer attitudes with programs that are simple, affordable, effective, and accessible.

Chronic stress impairs rat growth and jejunal epithelial barrier function: role of mast cells

We examined the impact of chronic stress on rat growth rate and intestinal epithelial physiology and the role of mast cells in these responses. Mast cell-deficient (Ws/Ws) rats and +/+ littermate controls were submitted to water avoidance stress or sham stress, 1 h/day, for 5 days. Seven hours after the last sham or stress session, jejunal segments were mounted in Ussing chambers, in which secretion and permeability were measured. Body weight (as a growth index) and food intake were determined daily. Stress increased baseline jejunal epithelial ion secretion (indicated by short-circuit current), ionic permeability (conductance), and macromolecular permeability (horseradish peroxidase flux) in +/+ rats, but not in Ws/Ws rats, compared with nonstressed controls. Stress induced weight loss and reduced food intake similarly in the groups. In +/+ rats, these parameters remained altered 24-72 h after the cessation of stress. Modulation of stress-induced mucosal mast cell activation may help in the management of certain intestinal conditions involving epithelial pathophysiology.

Probing the "active site" of diamine oxidase: structure-activity relations for histamine potentiation by O-alkylhydroxylamines on colonic epithelium

The responses of the canine colonic epithelium to histamine are potentiated by O-alkylhydroxylamines. A study of a series of such compounds suggested that active compounds had the structure R-O-NH2, substitution of a nitrogen led to total loss of activity. The locus of the potentiation effect was traced to the inhibition of diamine oxidase. A new series of aliphatic and aromatic O-alkylhydroxylamines were synthesized to explore further the structure-activity relations of this effect. The potentiating effects of these compounds were determined by examining the changes in short circuit current (Isc) produced by histamine and from the activity of a soluble preparation of diamine oxidase. We found that 1) branched compounds are less active than their straight chain counterparts, 2) greater steric bulk of the aliphatic substituent decreased activity, 3) the presence of a double bond had no significant effect though a triple bond reduced activity, 4) longer straight chain compounds were less active than the shorter chain derivatives and 5) all benzylic compounds were less active than the straight chain aliphatics. O-1-benzyl was inactive however the meta or para oxygen substituted compounds as well as the O-(1-E-Cinnamyl) derivative were active. A current model for the action of diamine oxidase proposes a crucial role for a trihydroxyphenylalanine quinone cofactor as part of the active site together with a copper atom. Using molecular modeling based on our inhibition data we are able to define the region of space that is just beyond the reactive carbonyl of the trihydroxyphenylalanine residue at the active site of diamine oxidase. We suggest that a negatively charged species, such as an aspartate or a glutamate, resides in a trough about 7 to 8 A from the trihydroxyphenylalanine carbonyl carbon and this species aids in the strong selective binding of substrates such as putrescine and histamine.

Ineffectiveness of the presence of H-ras/p53 combination of mutations in squamous cell carcinoma cells to induce a conversion of a nontumorigenic to a tumorigenic phenotype

Human tumor cells have properties in vitro or in surrogate hosts that are distinct from those of normal cells, such as immortality, anchorage independence, and tumor formation in nude mice. However, different cells from individual tumors may exhibit some, but not all of these features. In previous years, human tumor cell lines derived from different tumor and tissue types have been studied to determine those molecular changes that are associated with the in vitro properties listed above and with tumorigenicity in nude mice. In the present study, seven cell lines derived from human tumors were characterized for p53 and ras mutations that may occur in SCC tumor phenotypes and for tumor formation in nude mice. This investigation was designed to examine whether co-occurrence of mutated ras and p53 lead to a malignant stage in the progression process. None of the seven cell lines contained mutations in the recognized "hot spots" of the p53 tumor suppressor gene, but four had a nonsense/splice mutation in codon 126 and a mutation in codon 12 of the H-ras gene. The remaining three cell lines had p53 mutations in intron 5, in codon 193, and a missense mutation in codon 126, respectively. Four of seven cell lines were nontumorigenic; two of these cell lines contained a nonsense p53-126 mutation and mutated ras; one had a missense mutation at codon 126 but no mutated ras; the the fourth had only a p53 mutation at codon 193. Two of the nontumorigenic cell lines were converted to tumorigenicity after treatment with methyl methanesulfonate or N-methyl-N'-nitro-N-nitrosoguanidine with no apparent additional mutations in either gene. Our analysis revealed that there was a high frequency of genetic diversity and mutations in both p53 and H-ras. There was also a lack of a causal relationship in the presence of mutations in p53 and the cells' ability to exhibit a malignant potential in nude mice.

Functional subtyping of histamine receptors on the canine proximal colonic mucosa

The receptors involved in the neural and non-neural effects of histamine on the canine proximal colon in vitro were defined functionally by using selective agonists and antagonists. Two preparations, a ganglionated mucosa and an aganglionated epithelium, were set up in Ussing chambers and short-circuit currents were monitored. The mucosa was obtained by removing the circular and longitudinal muscles, but keeping intact the muscularis mucosa and attendant submucosal plexuses, whereas the epithelium was devoid of that layer as well. On the mucosal preparation, histamine, 2-methylhistamine (2-MH) and 2-pyridylethylamine (PEA), a histamine (H)1-selective agonist elicited responses which were inhibited by pretreatment with tetrodotoxin and H1 antagonists (mepyramine). Responses to dimaprit (H2 agonist) were seen only at high concentrations and these were unaffected by tetrodotoxin; no responses were noted with any of the other agonists tested. By contrast, responses on the epithelial preparation were seen with histamine as well as H1 (PEA and 2-MH), H2 (dimaprit, impromidine and 4-MH) and H3-selective agonists [R(-)-alpha-MH]. Responses to PEA were inhibited selectively by mepyramine (H1 antagonist), whereas those elicited by H2 agonists were antagonized only by ranitidine (H2 antagonist). Both mepyramine and ranitidine significantly reduced the epithelial responses of 2-MH. Responses to [R(-)-alpha-MH] (H3 agonist) were seen only at high concentrations and were inhibited by ranitidine, but not by thioperamide (H3 antagonist). The effects of histamine were unaffected by pretreatment with indomethacin. Thus, neural effects are mediated by the occupation of H1 receptors (presumably on the submucosal neurons), whereas the non-neural (direct) effects result from the occupation of either H1 or H2 receptors. H3 receptors are functionally absent. Flux experiments showed that histamine, dimaprit and PEA produced marked increases in short circuit current that were accompanied by significant increases in JsmCl leading to decreases in JnetCl. Dimaprit stimulated an increase in JnetNa, largely as a result of increases in JmsNa. A negative residual flux (Jres) was seen with all three agonists. Thus, neural effects involve H1 receptors; non-neural effects involve both H1 and H2 receptors. Cl- secretion results from occupation of either receptor subset. Only the selective H2-agonist, dimaprit, produced significant changes in JnetNa. H3 receptors are functionally absent.

Adenosine A1 receptors are not involved in contraction of canine gastric muscularis mucosae by adenosine analogues

In vitro contractility studies were conducted in canine gastric muscularis mucosae muscle strips with the adenosine analogues 2-chloroadenosine (CIAD), 5'-N-ethylcarboxamidoadenosine (NECA), 5'-(N-cyclopropyl)-carboxamidoadenosine (CPCA), R-N6-(2-phenylisopropyl)adenosine (R-PIA), S-PIA, N6-cyclohexyladenosine (CHA) and (2-p-carboxyethyl)phenylamino-5'-N-carboxamidoadenosine (CGS21680) as well as the A1-selective antagonist 1,3-dipropyl-8-cyclopentylxanthine (DPCPX). Adenosine analogues contracted the muscle strips with the following rank order of potency: CPCA > NECA > CIAD > R-PIA > CHA > S-PIA > CGS21680. CPCA, R-PIA, and CHA were partial agonists. At a concentration selective for adenosine A1 receptors (50 nM), DPCPX did not alter the concentration-response curves to CIAD or CHA. However, at higher concentrations (1-10 microM), DPCPX antagonized CIAD-mediated contractions in a competitive manner (pA2 = 6.96; slope = 0.93). CIAD-mediated contraction was not altered by treatment of the muscle strips with tetrodotoxin (1 microgram/ml) or mepyramine (1 microM). Our results indicate that adenosine A1 receptors, nerves or mast cells are not involved in contraction of canine gastric muscularis mucosae by adenosine analogues.

Effects of bradykinin on the canine proximal colon

The canine proximal colon set up in Ussing chambers responded to the serosal addition of bradykinin (BK) with changes in short-circuit current (Isc). Two preparations were used to analyze these effects - an innervated mucosal preparation and a 'functionally nerve-free' epithelial preparation. The specific questions that this study sought to answer were (1) is there a significant neural component to the effects noted?, and (2) what is the receptor subtype involved? BK produced dose-dependent increases across both the mucosa and the epithelial preparations. A secondary decrease in Isc was noted in the mucosal but not the epithelial preparation. Tetrodotoxin (TTX) significantly inhibited the magnitude of mucosal responses and delayed their onset as well, indicating the presence of a significant neural component. Addition of the B2 antagonist, D-Arg0[Hyp3,Thi5,8, D-Phe7]BK produced a surmountable inhibition of the responses to the agonist. The B1 selective agonist, des-Arg9BK produced increases in Isc across both preparations, though TTX had no significant effects on these responses. Cross-desensitization was seen between BK and des-Arg9 BK. However, since the B1 selective antagonist, des-Arg9[Leu8]BK acted as a partial agonist in our preparation, these effects could not be defined further. Clearly, B2 receptors are involved in mediating canine colonic BK responses, however the role of B1 receptors in this tissue requires further definition.

Characterization of translational frame exception patients in Duchenne/Becker muscular dystrophy

The clinical progression of Duchenne muscular dystrophy (DMD) patients with deletions can be predicted in 93% of cases by whether the deletion maintains or disrupts the translational reading frame (frameshift hypothesis). We have identified and studied a number of patients who have deletions that do not conform to the translational frame hypothesis. The most common exception to the frameshift hypothesis is the deletion of exons 3 to 7 which disrupts the translational reading frame. We identified a Becker muscular dystrophy (BMD) patient, an intermediate, and a DMD patient with this deletion. In all three cases, dystrophin was detected and localized to the membrane. One DMD patient with an inframe deletion of exons 4-18 produced no dystrophin. One patient with a mild intermediate phenotype and a deletion of exon 45, which shifts the reading frame, produced no dystrophin. Two patients with large inframe deletions had discordant phenotypes (exons 3-41, DMD; exons 13-48, BMD), but both produced dystrophin that localized to the sarcolemma. The DMD patient, 113, indicates that dystrophin with an intact carboxy terminus can be produced in Duchenne patients at levels equivalent to some Beckers. The dystrophin analysis from these patients, together with patients reported in the literature, indicate that more than one domain can localize dystrophin to the sarcolemma. Lastly, the data shows that although most patients show correlation of clinical severity to molecular data, there are rare patients which do not conform.

H1 contractile and H2 relaxant receptors in canine gastric muscularis mucosae

Histamine had two effects on the contractility of canine gastric muscularis mucosae in vitro: relaxation at or below 10 microM and contraction at higher concentrations. Selective agonists and antagonists were used to test the possibility that these effects were mediated by different receptor subtypes. The H1-selective agonist 2-pyridylethylamine (2-PEA) and the H2-selective agonist dimaprit contracted and relaxed this muscle, respectively, while the H3-selective agonist R-alpha-methylhistamine had no effect. The H1- and H2-selective antagonists mepyramine and ranitidine selectively blocked 2-PEA-mediated contractions and dimaprit-mediated relaxations, respectively. Agonist responses, were unaltered by tetrodotoxin, suggesting a site of action other than nerves. Our results indicate that canine gastric corpus muscularis mucosae possesses both contractile H1 and relaxant H2 receptors.

Histamine potentiation by hydroxylamines: structure-activity relations; inhibition of diamine oxidase

Hydroxylamines potentiated the responses of the canine colonic epithelium to histamine but not to other agonists such as serotonin or carbachol. We tested the hypothesis that an inhibition of histamine catabolism could explain the observed potentiation. A clear structure activity relation was defined, active compounds having the structure NH2-O-R, R being a simple uncharged aliphatic group. Active compounds delayed the disappearance of histamine from the bathing solutions and inhibited colonic diamine oxidase, an effect mimicked by standard inhibitors aminoguanidine and semicarbazide. Histamine agonists that possessed an imidazole nucleus (2- and 4-methylhistamine) were affected, whereas impromidine, 2 pyridylethylamine, and dimaprit were not. Agonist specificity combined with the enzyme data suggest an inhibition of histamine catabolism as a possible mechanism for the potentiating effects observed.

Epithelial and mucosal preparations from canine colon: responses to substance P

The hypothesis that substance P (SP) elicits both direct and indirect responses on the canine proximal colon was tested using two different in vitro preparations. The mucosa contained the muscularis mucosa and the attendant submucosal plexuses whereas the epithelium, being devoid of both, was functionally "nerve-free." Dose-dependent stimulation was noted on both preparations, increases in peak current (microamperes per squared centimeter) as well as charge transfers (millicoulombs per squared centimeter) were monitored. Tetrodotoxin significantly reduced mucosal responses whereas atropine and the H1 antagonists mepyramine and diphenhydramine had only marginal effects. None of these agents affected the responses of the epithelium to SP. Indomethacin significantly reduced responses in both preparations. Removal of Na+ or Cl- or the use of C- channel blockers (9-anthracene carboxylic acid and N-phenylanthranilic acid) produced a significant reduction of SP responses across the epithelium. Thus, SP has both direct and indirect affects on the colon; activation of the cyclooxygenase pathway could be significant.