ESMO expert consensus statements (ECS) on the definition, diagnosis, and management of HER2-low breast cancer.

Human epidermal growth factor receptor 2 (HER2)-low breast cancer has recently emerged as a targetable subset of breast tumors, based on the evidence from clinical trials of novel anti-HER2 antibody-drug conjugates. This evolution has raised several biological and clinical questions, warranting the establishment of consensus to optimally treat patients with HER2-low breast tumors. Between 2022 and 2023, the European Society for Medical Oncology (ESMO) held a virtual consensus-building process focused on HER2-low breast cancer. The consensus included a multidisciplinary panel of 32 leading experts in the management of breast cancer from nine different countries. The aim of the consensus was to develop statements on topics that are not covered in detail in the current ESMO Clinical Practice Guideline. The main topics identified for discussion were (i) biology of HER2-low breast cancer; (ii) pathologic diagnosis of HER2-low breast cancer; (iii) clinical management of HER2-low metastatic breast cancer; and (iv) clinical trial design for HER2-low breast cancer. The expert panel was divided into four working groups to address questions relating to one of the four topics outlined above. A review of the relevant scientific literature was conducted in advance. Consensus statements were developed by the working groups and then presented to the entire panel for further discussion and amendment before voting. This article presents the developed statements, including findings from the expert panel discussions, expert opinion, and a summary of evidence supporting each statement.

Endovascular Release of a 50-Year-Old Adams-Deweese IVC Clip to Facilitate Percutaneous Repair of Mitral Valve Regurgitation.

Percutaneous mitral valve (MV) repair using MitraClip requires large-caliber venous access. We describe a patient with a ligated inferior vena cava due to an Adams-DeWeese clip placed 50 years prior, who had progressive shortness of breath and lower extremity symptoms secondary to severe mitral regurgitation and chronic iliocaval deep venous thrombosis. Due to comorbidities, MitraClip was recommended over surgery for MV repair. Caval luminal gain was required to facilitate endovascular access for the MitraClip system. Stent-mediated release of the inferior vena cava clip allowed successful passage of the delivery sheath from the common femoral vein to MV and subsequent valve repair.

Long-term outcomes after adjuvant treatment of sequential versus combination docetaxel with doxorubicin and cyclophosphamide in node-positive breast cancer: BCIRG-005 randomized trial.

BACKGROUND: The optimal regimen for adjuvant breast cancer chemotherapy is undefined. We compared sequential to concurrent combination of doxorubicin and cyclophosphamide with docetaxel chemotherapy in women with node-positive non-metastatic breast cancer. We report the final, 10-year analysis of disease-free survival (DFS), overall survival (OS), and long-term safety. PATIENTS AND METHODS: A total of 3298 women with HER2 nonamplified breast cancer were randomized to doxorubicin and cyclophosphamide every 3 weeks for four cycles followed by docetaxel (AC → T) every 3 weeks for four cycles or docetaxel, doxorubicin, and cyclophosphamide (TAC) every 3 weeks for six cycles. The patients received standard radiotherapy and endocrine therapy and were followed up for 10 years with annual clinical evaluation and mammography. RESULTS: The 10-year DFS rates were 66.5% in the AC → T arm and 66.3% in the TAC arm (P = 0.749). OS was 79.9% in the AC → T arm and 78.9% in the TAC arm (P = 0.506). TAC was associated with higher rates of febrile neutropenia, although G-CSF primary prophylaxis greatly reduced this risk. AC → T was associated with a higher rate of myalgia, hand-foot syndrome, fluid retention, and sensory neuropathy. CONCLUSION: This 10-year analysis of the BCIRG-005 trial confirmed that the efficacy of TAC was not superior to AC → T in women with node-positive early breast cancer. The toxicity profiles differ between arms and were consistent with previous reports. The TAC regimen with G-CSF support provides shorter adjuvant treatment duration with less toxicity. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT00312208.

Hemiparasitic plant impacts animal and plant communities across four trophic levels.

Understanding the impact of species on community structure is a fundamental question in ecology. There is a growing body of evidence that suggests that both subdominant species and parasites can have disproportionately large effects on other organisms. Here we report those impacts for a species that is both subdominant and parasitic, the hemiparasite Rhinanthus minor. While the impact of parasitic angiosperms on their hosts and, to a lesser degree, coexisting plant species, has been well characterized, much less is known about their effects on higher trophic levels: We experimentally manipulated field densities of the hemiparasite Rhinanthus minor in a species-rich grassland, comparing the plant and invertebrate communities in plots where it was removed, present at natural densities, or present at enhanced densities. Plots with natural and enhanced densities of R. minor had lower plant biomass than plots without the hemiparasite, but enhanced densities almost doubled the abundance of invertebrates within the plots across all trophic levels, with effects evident in herbivores, predators, and detritivores. The hemiparasite R. minor, despite being a subdominant and transient component within plant communities that it inhabits, has profound effects on four different trophic levels. These effects persist beyond the life of the hemiparasite, emphasizing its role as a keystone species in grassland communities.

Assessment of HER2 gene amplification in adenocarcinomas of the stomach or gastroesophageal junction in the INT-0116/SWOG9008 clinical trial.

BACKGROUND: Trastuzumab has been approved for patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic gastric carcinoma; however, relatively little is known about the role of HER2 in the natural history of this disease. PATIENTS AND METHODS: Patients enrolled in the INT-0116/SWOG9008 phase III gastric cancer clinical trial with available tissue specimens were retrospectively evaluated for HER2 gene amplification by FISH and overexpression by immunohistochemistry (IHC). The original trial was designed to evaluate the benefit of postoperative chemoradiation compared with surgery alone. RESULTS: HER2 gene amplification rate by FISH was 10.9% among 258 patients evaluated. HER2 overexpression rate by IHC was 12.2% among 148 patients evaluated, with 90% agreement between FISH and IHC. There was a significant interaction between HER2 amplification and treatment with respect to both disease-free survival (DFS) (P = 0.020) and overall survival (OS) (P = 0.034). Among patients with HER2-non-amplified cancers, treated patients had a median OS of 44 months compared with 24 months in the surgery-only arm (P = 0.003). Among patients with HER2-amplified cancers, there was no significant difference in survival based on treatment arm. HER2 status was not a prognostic marker among patients who received no postoperative chemoradiation. CONCLUSION: Patients lacking HER2 amplification benefited from treatment as indicated by both DFS and OS. CLINICAL TRIAL: INT-0116/SWOG9008 phase III.

Pregnancy outcome following in vitro fertilization-embryo transfer according to the percentage of metaphase II oocytes retrieved.

PURPOSE: To determine if the presence of a lower percentage of metaphase II eggs during oocyte retrieval leads to a lower fertilization rate of these metaphase II eggs since they may be more likely to be not quite fully mature, and to determine if transfer of embryos made from these eggs leads to lower pregnancy and implantation rates. METHODS: Fertilization and pregnancy rates determined according to deciles of percent of metaphase II eggs beginning with <30%. RESULTS: Though there was no difference in fertilization rates when comparing those with <60% metaphase II eggs vs a 60%, there were significantly higher clinical and live delivered pregnancy rates and implantation rates when there were a 60% of the eggs retrieved that were metaphase II. CONCLUSIONS: An inferior pregnancy outcome with a lower percentage of metaphase II eggs despite similar fertilization rates is consistent with the hypothesis that subtle full maturation defects may result in pregnancy failure despite embryo transfer.

"Embryo glue" does not seem to improve chances of subsequent pregnancy in refractory in vitro fertilization cases.

PURPOSE: To determine if the use of Embryo glue improves implantation and pregnancy rates following embryo transfer (ET) in women who failed to conceive in three previous attempts. METHODS: A matched controlled study was performed in women undergoing IVF-ET, donor oocyte recipients and women using their own oocytes having fresh or frozen ETs. A woman having Embryo glue was matched with the very next woman not using glue within six months of age and having the same number of previous failed ETs. RESULTS: Embryo glue did not seem to improve pregnancy or implantation rates. In fact, in evaluating fresh embryo transfers there was a significantly higher live delivered pregnancy rate in the women not using Embryo glue (39.3%) vs those using the glue (14.3%). CONCLUSIONS: Embryo glue does not improve pregnancy outcome in women failing in previous IVF cycles.

Oocytes from women of advanced reproductive age do not appear to have an increased risk of zona pellucida hardening.

PURPOSE: To test the hypothesis that very advanced reproductive age leads to an increased risk of zona pellucida hardening by comparing fertilization rates and rates of failed fertilization with conventional oocyte insemination vs intracytoplasmic sperm injection (ICSI). METHODS: Women aged > or = 45 were given the option of ICSI vs conventional oocyte insemination in circumstances where there was no male factor present. They were advised of the theoretical benefit of ICSI overcoming zona hardening but also advised that ICSI might lower pregnancy rates and is more costly. RESULTS: There were 364 cycles evaluated and 74% chose ICSI. The failed fertilization rates were similar--28.4% (66/232) for ICSI vs 26.5% (35/132) for conventional insemination. The fertilization rates were similar 56.0% with ICSI vs 50.9% with conventional oocyte insemination. CONCLUSION: Based on similar fertilization and failed fertilization rates in women aged > or = 45 undergoing IVF-ET, zona hardening does not appear to be a consequence of reproductive aging.

Variation for host range within and among populations of the parasitic plant Striga hermonthica.

Striga hermonthica is an angiosperm parasite that causes substantial damage to a wide variety of cereal crop species, and to the livelihoods of subsistence farmers in sub-Saharan Africa. The broad host range of this parasite makes it a fascinating model for the study of host-parasite interactions, and suggests that effective long-term control strategies for the parasite will require an understanding of the potential for host range adaptation in parasite populations. We used a controlled experiment to test the extent to which the success or failure of S. hermonthica parasites to develop on a particular host cultivar (host resistance/compatibility) depends upon the identity of interacting host genotypes and parasite populations. We also tested the hypothesis that there is a genetic component to host range within individual S. hermonthica populations, using three rice cultivars with known, contrasting abilities to resist infection. The developmental success of S. hermonthica parasites growing on different rice-host cultivars (genotypes) depended significantly on a parasite population by host-genotype interaction. Genetic analysis using amplified fragment length polymorphism (AFLP) markers revealed that a small subset of AFLP markers showed 'outlier' genetic differentiation among sub-populations of S. hermonthica attached to different host cultivars. We suggest that, this indicates a genetic component to host range within populations of S. hermonthica, and that a detailed understanding of the genomic loci involved will be crucial in understanding host-parasite specificity and in breeding crop cultivars with broad spectrum resistance to S. hermonthica.

Use of perfluorodecalin for pancreatic islet culture prior to transplantation: a liquid-liquid interface culture system--preliminary report.

Although the issue remains controversial, short-term culture is probably beneficial for islet graft quality. However, significant islet loss is invariably observed. This is related to reduced survival of large islets, which is compromised by hypoxia under standard culture conditions. We aimed to develop a method of culture, which would avoid exposure to relative hypoxia and hence maintain the quality of islets. Isolated rat islets cultured for 48 h in a liquid-liquid interface culture system (LICS) with a perfluorocarbon were compared to islets cultured under standard (C1) and suboptimal conditions (C2). Islets were tested for viability and response to a glucose challenge, and a marginal mass was transplanted into syngeneic diabetic recipients. The viability of islets after 24-h culture in LICS was higher than in C1 and C2 groups (89.0% vs. 77.5% and 64.6%, respectively) and decreased with time to reach 79.0%, 62.9%, and 53.4% after 72-h culture. The stimulation index in LICS-cultured islets was also significantly higher than in C1 and C2 groups (12.3 ± 0.4 vs. 5.8 ± 0.5 and 4.1 ± 0.2, respectively). Following transplantation of LICS-cultured islets 50% of recipients were rendered normoglycemic compared with 14.3% and 31.3% for C2 and fresh islets, respectively. Our liquid-liquid interface culture system using perfluorodecalin provides optimized culture conditions, which preserve both islet viability and their ability to engraft successfully after intraportal transplantation and could be used for islet transportation.

Cryopreservation of blastocysts using a modification of a simplified freezing protocol with a one step removal of cryoprotectant successfully used previously to freeze 2 pronuclear or multi-cell embryos.

PURPOSE: To describe a modification of a simplified freezing protocol for the cryopreservation of blastocysts. METHODS: 1.5 M glycerol was substituted as a cryoprotectant instead of propanediol. RESULTS: There was a survival rate of 59.1% (13/22) with three live deliveries in seven transfers (42.9% per transfer). The implantation rate was 28.6% (4/14). CONCLUSIONS: This is the first description of a new technique for freezing blastocysts. A larger series is needed to determine if the good pregnancy rates will continue.

HER2 gene amplification and EGFR expression in a large cohort of surgically staged patients with nonendometrioid (type II) endometrial cancer.

Type II endometrial cancers (uterine serous papillary and clear cell histologies) represent rare but highly aggressive variants of endometrial cancer (EC). HER2 and EGFR may be differentially expressed in type II EC. Here, we evaluate the clinical role of HER2 and EGFR in a large cohort of surgically staged patients with type II (nonendometrioid) EC and compare the findings with those seen in a representative cohort of type I (endometrioid) EC. In this study HER2 gene amplification was studied by fluorescence in situ hybridisation (FISH) and EGFR expression by immunohistochemistry. Tissue microarrays were constructed from 279 patients with EC (145 patients with type I and 134 patients with type II EC). All patients were completely surgically staged and long-term clinical follow up was available for 258 patients. The rate of HER2 gene amplification was significantly higher in type II EC compared with type I EC (17 vs 1%, P<0.001). HER2 gene amplification was detected in 17 and 16% of the cases with uterine serous papillary and clear cell type histology, respectively. In contrast, EGFR expression was significantly lower in type II compared with type I EC (34 vs 46%, P=0.041). EGFR expression but not HER2 gene amplification was significantly associated with poor overall survival in patients with type II EC, (EGFR, median survival 20 vs 33 months, P=0.028; HER2, median survival 18 vs 29 months, P=0.113) and EGFR expression retained prognostic independence when adjusting for histology, stage, grade, and age (EGFR, P=0.0197; HER2, P=0.7855). We conclude that assessment of HER2 gene amplification and/or EGFR expression may help to select type II EC patients who could benefit from therapeutic strategies targeting both HER2 and EGFR.

Global patterns of gene expression in rice cultivars undergoing a susceptible or resistant interaction with the parasitic plant Striga hermonthica.

Striga hermonthica is a root hemiparasite of cereals that causes devastating loss of yield. Recently, a rice cultivar, Nipponbare, was discovered, which exhibits post-attachment resistance to this parasite and quantitative trait loci (QTL) associated with the resistance were identified. Changes in gene expression in susceptible (IAC 165) and resistant (Nipponbare) rice cultivars were profiled using rice whole-genome microarrays. In addition to a functional categorization of changes in gene expression, genes that were significantly up-regulated within resistance QTL were identified. The resistance reaction was characterized by up-regulation of defence genes, including pathogenesis-related proteins, pleiotropic drug resistance ABC transporters, genes involved in phenylpropanoid metabolism and WRKY transcription factors. These changes in gene expression resemble those associated with resistance to microbial pathogens. Three genes encoding proteins of unknown function, within a major resistance QTL on chromosome 12, were highly up-regulated and are excellent candidate resistance genes. The susceptible interaction was characterized by large-scale down-regulation of gene expression, particularly within the functional categories plant growth regulator signalling and metabolism, biogenesis of cellular components and cell division. Up-regulated genes included nutrient transporters, enzymes of amino acid metabolism and some abiotic stress genes.

Can we predict future improvement in glycaemic control?

AIMS: To determine the factors responsible for poor glycaemic control in diabetes and whether any such factors are associated with likely improvement in glycaemic control. METHODS: A prospective cohort study of 130 diabetic patients with poor glycaemic control (HbA(1c )> or = 10.0%) with 1-year follow-up in a teaching hospital Diabetes Clinic. Changes in HbA(1c) were measured after 1 year. RESULTS: Poor glycaemic control was attributed to one of 15 possible causes. Those cases due to recent diagnosis of diabetes, inadequate treatment with diet, oral glucose-lowering agents or insulin, exacerbation of co-existent medical problems, recent stressful life-events and missed clinic appointments were all associated with significant improvement in HbA(1c) at 12 months. Patients with low mood or alcohol excess, inadequate blood glucose monitoring, poor exercise/sedentary lifestyle, refusal to take tablets or underdosing and refusal to take insulin at all or to increase the dose were all associated with continuing poor glycaemic control at 12 months. The patients were divided almost equally between the two groups. CONCLUSIONS: In patients with poor glycaemic control, it is possible by simple features identified at clinic to predict which individuals are likely to show improvement in control and which will not. These findings have not been reported previously and suggest that about half of individuals with poor control will improve within our current diabetes clinic practice. Additional strategies will be required to address those individuals who are not likely to respond.

Elevated serum levels of visfatin in gestational diabetes: a comparative study across various degrees of glucose tolerance.

AIMS/HYPOTHESIS: Concentrations of visfatin are increased in insulin-resistant conditions, but the relationship between visfatin and insulin and/or insulin resistance indices in pregnancy remains unclear. Insulin resistance in pregnancy is further accentuated in women with gestational diabetes mellitus (GDM). Thus we assessed serum levels of visfatin in pregnant women with varying degrees of glucose tolerance. MATERIALS AND METHODS: Fasting visfatin levels were measured at 28 weeks of gestation in 51 women divided according to their response to a 50-g glucose challenge test (GCT) and a 75-g OGTT: control subjects (n = 20) had normal responses to both a GCT and an OGTT; the intermediate group (IG; n = 15) had a false-positive GCT, but a normal OGTT; the GDM group (n = 16) had abnormal GCTs and OGTTs. RESULTS: There were no age or BMI differences between analysed groups. Across the subgroups there was a progressive increase in glucose and insulin at 120 min of the OGTT (p < 0.01). This was accompanied by an increase in visfatin, from 76.8 +/- 14.1 ng/ml in the control subjects, to 84.0 +/- 14.7 ng/ml in the IG group and 93.1 +/- 12.3 ng/ml in the GDM group (p < 0.01 for GDM vs control subjects). There was a positive correlation between visfatin and fasting insulin (r = 0.38, p = 0.007) and insulin at 120 min of the OGTT (r = 0.39, p = 0.006). CONCLUSIONS/INTERPRETATION: An increase in fasting visfatin, the levels of which correlate with both fasting and post-glucose-load insulin concentrations, accompanies worsening glucose tolerance in the third trimester of pregnancy. However, the significance of these findings, and in particular the role of visfatin in the regulation of insulin sensitivity during pregnancy, remains to be elucidated.

Management strategies for brittle diabetes.

Type 1 diabetes is an intrinsically unstable condition. However, the term "brittle diabetes" is reserved for those cases in which the instability, whatever its cause, results in disruption of life and often recurrent and/or prolonged hospitalization. It affects 3/1000 insulin-dependent diabetic patients, mainly young women. Its prognosis is poor with lower quality of life scores, more microvascular and pregnancy complications and shortened life expectancy. Three forms have been described: recurrent diabetic ketoacidosis, predominant hypoglycemic forms and mixed instability. Main causes of brittleness include malabsorption, certain drugs (alcohol, antipsychotics), defective insulin absorption or degradation, defect of hyperglycemic hormones especially glucocorticoid and glucagon, and above all delayed gastric emptying as a result of autonomic neuropathy. Psychosocial factors are very important and factitious brittleness may lead to a self-perpetuating condition. The assessment of brittle diabetes requires quantification of the variability of blood glucose levels. To quantify instability, measures which have been developed, include Mean Amplitude of the largest Glycemic Excursions (MAGE), Mean Of Daily Differences (MODD), Lability Index (LI), Low Blood Glucose Index (LBGI), Clarke's score, Hyposcore, and continuous blood glucose monitoring. Once psychogenic problems have been excluded, therapeutic strategies require firstly, the treatment of underlying organic causes of the brittleness whenever possible and secondly optimising standard insulin therapy using analogues, multiple injections and consideration of Continuous Subcutaneous Insulin Infusion. Alternative approaches may still be needed for the most severely affected patients. Isolated islet transplantation (IIT), which restores glucose sensing, should be considered in cases of hypoglycaemic unawareness and/or lability especially if the body mass index is < 25, but with current immunosuppressive protocols patients must have normal renal function and preferably no plans for pregnancy. Implantable pumps have advantages for patients who either weigh more than 80 kgs or have abnormalities of kidney or liver function or are highly sensitised.

Quantifying the role of factors that limit attainment of K/DOQI urea reduction ratio dialytic goal.

BACKGROUND: For many ESRD patients who are prescribed a certain level of hemodialysis (HD), delivered dose often does not achieve prescription. While various causes have been well-documented in the literature, there are no available data that may be used in predicting the likelihood of achieving a particular urea reduction ratios (URR) goal based on the number of these factors present. This study evaluated URRs of all patients in an outpatient HD unit for a 6-month period to identify factors significant in attaining goal in order to predict likelihood of goal attainment based on number of factors present. METHODS: The inclusion criterion in this study was any HD patient during the study period with > or = 3 monthly URR measurements. Of 203 patients, 169 qualified for 900 treatments. A database was created for each patient that included demographics, factors affecting K(urea), time and access. After grouping percentages of patients with URR > or = 70%, 65 - < 70%, and < 65%, we studied a subset of 107 patients (568 treatments) that had at least 1 URR < 70% to identify factors associated with a URR of > or = 65% vs. < 65%. To determine factors predictive of URR > or = 65%, a sum percentage across all treatments was created for each patient. Mean percentages were compared between groups created by constant characteristics (e.g. gender, DM). Variables, e.g. catheters, were summarized as a percentage for each patient, and these percentages were correlated with rate of URR > or = 65%. Time was assigned a value of 0 (prescribed), positive (longer), negative (shorter), summarized as per-patient mean. After these factors were identified, each treatment was reviewed to determine the percentage of treatments > or = 65% with the number of statistically significant factors present. RESULTS: The average, across all patients, of percentage of treatments meeting URR > or = 65% was 87.95% while a mean of 66.65% met URR > or = 70%. Factors associated with percentage of treatments per patient not meeting K/DOQI goal included catheter use (Spearman's correlation = -0.31, p = 0.001), blood flow < 90% of prescription (Spearman's correlation = -0.17, p = 0.041), younger age (> or = 61 years vs. < 61 years, p = 0.001: patients > or = 61 years had a higher percentage of URR > or = 65%), inadequate access for prescribed blood flow (Spearman's correlation = -0.32, p = 0.001), actual time vs. prescribed time (Spearman's correlation = 0.25, p = 0.009), and HD w/o heparin (Spearman's correlation = -0.21, p = 0.031). In 178 treatments, all having "good" values (no catheter, blood flow > or = 90% prescribed, age < or = 61 years, etc.), the percentage of treatments meeting URR of < or = 65 was 96.1%. With 1 bad value factor: 83.8% of 216 treatments met goal, 2 bad value factors: 71.7% of 106 met goal, 3 bad value factors: 60.5% of 43 met goal. With 4 or 5 bad value factors: only 36.1% of 25 treatments met goal. CONCLUSIONS: Significant factors in meeting adequacy defined by K/DOQI in rank order (excluding age) include inadequate access for prescribed blood flow, catheter use, time, lack of heparin and inability to achieve blood flow > or = 90% prescribed. A direct correlation exists between number of these factors present and K/DOQI goal attainment in a given treatment.

A novel form of resistance in rice to the angiosperm parasite Striga hermonthica.

The root hemiparasitic weed Striga hermonthica is a serious constraint to grain production of economically important cereals in sub-Saharan Africa. Breeding for parasite resistance in cereals is widely recognized as the most sustainable form of long-term control; however, advances have been limited owing to a lack of cereal germplasm demonstrating postattachment resistance to Striga. Here, we identify a cultivar of rice (Nipponbare) that exhibits strong postattachment resistance to S. hermonthica; the parasite penetrates the host root cortex but does not form parasite-host xylem-xylem connections. In order to identify the genomic regions contributing to this resistance, a mapping population of backcross inbred lines between the resistant (Nipponbare) and susceptible (Kasalath) parents were evaluated for resistance to S. hermonthica. Composite interval mapping located seven putative quantitative trait loci (QTL) explaining 31% of the overall phenotypic variance; a second, independent, screen confirmed four of these QTL. Relative to the parental lines, allelic substitutions at these QTL altered the phenotype by at least 0.5 of a phenotypic standard deviation. Thus, they should be regarded as major genes and are likely to be useful in breeding programmes to enhance host resistance.

Foliar pH as a new plant trait: can it explain variation in foliar chemistry and carbon cycling processes among subarctic plant species and types?

Plant traits have become popular as predictors of interspecific variation in important ecosystem properties and processes. Here we introduce foliar pH as a possible new plant trait, and tested whether (1) green leaf pH or leaf litter pH correlates with biochemical and structural foliar traits that are linked to biogeochemical cycling; (2) there is consistent variation in green leaf pH or leaf litter pH among plant types as defined by nutrient uptake mode and higher taxonomy; (3) green leaf pH can predict a significant proportion of variation in leaf digestibility among plant species and types; (4) leaf litter pH can predict a significant proportion of variation in leaf litter decomposability among plant species and types. We found some evidence in support of all four hypotheses for a wide range of species in a subarctic flora, although cryptogams (fern allies and a moss) tended to weaken the patterns by showing relatively poor leaf digestibility or litter decomposability at a given pH. Among seed plant species, green leaf pH itself explained only up to a third of the interspecific variation in leaf digestibility and leaf litter up to a quarter of the interspecific variation in leaf litter decomposability. However, foliar pH substantially improved the power of foliar lignin and/or cellulose concentrations as predictors of these processes when added to regression models as a second variable. When species were aggregated into plant types as defined by higher taxonomy and nutrient uptake mode, green-specific leaf area was a more powerful predictor of digestibility or decomposability than any of the biochemical traits including pH. The usefulness of foliar pH as a new predictive trait, whether or not in combination with other traits, remains to be tested across more plant species, types and biomes, and also in relation to other plant or ecosystem traits and processes.

An improved method of fluorescent dual insulin and endothelial staining allows visualisation of the revascularisation of intraportally transplanted islets.

BACKGROUND: Intraportally transplanted islets are avascular at the time of transplantation and take up to 14 days to fully revascularize, during which time up to 60% of islet mass may be lost. To investigate and improve islet revascularization, a robust method for the visualization and quantification of this process is required. METHODS: Islets isolated from Lewis rats were transplanted intraportally into the liver of diabetic syngeneic Lewis recipients. The animals were humanely killed either on the day of transplant or at 3, 5, 7, or 14 days posttransplant. The harvested livers were sectioned and stained with Bandeiraea simplicifolia lectin (for endothelial cells) and anti-insulin antibody and counterstained with DAPI. The slides were visualized with a fluorescent microscope. RESULTS: Islets were visualized over the whole time course. Insulin and endothelial staining was clearly visualized on the day of transplantation, but by day 3 endothelial staining was scarce within the islet. By day 5, early vessel formation could be seen within the islet, but insulin staining was patchy and associated with apoptotic nuclei. By day 7, vessels could be seen throughout the islet and insulin staining had returned. Day 14 sections showed a fully revascularized islet. CONCLUSIONS: The staining provided good delineation of islet endothelium and beta-cell location, with clear observation of the revascularization process. This technique also suggests that days 3 through 5 may be a critical period for islet survival and provides a good model for studying the effects of manipulating the revascularization process.