Lethal and Sub-lethal Implications of Sodium Chloride Exposure for Adult Unionid Mussel Species: Eurynia dilatata and Lasmigona costata

The elevated use of salt as a de-icing agent on roads in Canada is causing an increase in the chloride concentration of freshwater ecosystems. Freshwater Unionid mussels are a group of organisms that are sensitive to increases in chloride levels. Unionids have greater diversity in North America than anywhere else on Earth, but they are also one of the most imperiled groups of organisms. This underscores the importance of understanding the effect that increasing salt exposure has on these threatened species. There are more data on the acute toxicity of chloride to Unionids than on chronic toxicity. This study investigated the effect of chronic sodium chloride exposure on the survival and filtering activity of two Unionid species (Eurynia dilatata, and Lasmigona costata) and assessed the effect on the metabolome in L. costata hemolymph. The concentration causing mortality after 28 days of exposure was similar for E. dilatata (1893 mg Cl^-/L) and L. costata (1903 mg Cl^-/L). Significant changes in the metabolome of the L. costata hemolymph were observed for mussels exposed to non-lethal concentrations. For example, several phosphatidylethanolamines, several hydroxyeicosatetraenoic acids, pyropheophorbide-a, and alpha-linolenic acid were significantly upregulated in the hemolymph of mussels exposed to 1000 mg Cl^-/L for 28 days. While no mortality occurred in the treatment, elevated metabolites in the hemolymph are an indicator of stress.

Safety and efficacy of tenecteplase in patients with wake-up stroke assessed by non-contrast CT (TWIST): a multicentre, open-label, randomised controlled trial

BACKGROUND

Current evidence supports the use of intravenous thrombolysis with alteplase in patients with wake-up stroke selected with MRI or perfusion imaging and is recommended in clinical guidelines. However, access to advanced imaging techniques is often scarce. We aimed to determine whether thrombolytic treatment with intravenous tenecteplase given within 4·5 h of awakening improves functional outcome in patients with ischaemic wake-up stroke selected using non-contrast CT.

METHODS

TWIST was an investigator-initiated, multicentre, open-label, randomised controlled trial with blinded endpoint assessment, conducted at 77 hospitals in ten countries. We included patients aged 18 years or older with acute ischaemic stroke symptoms upon awakening, limb weakness, a National Institutes of Health Stroke Scale (NIHSS) score of 3 or higher or aphasia, a non-contrast CT examination of the head, and the ability to receive tenecteplase within 4·5 h of awakening. Patients were randomly assigned (1:1) to either a single intravenous bolus of tenecteplase 0·25 mg per kg of bodyweight (maximum 25 mg) or control (no thrombolysis) using a central, web-based, computer-generated randomisation schedule. Trained research personnel, who conducted telephone interviews at 90 days (follow-up), were masked to treatment allocation. Clinical assessments were performed on day 1 (at baseline) and day 7 of hospital admission (or at discharge, whichever occurred first). The primary outcome was functional outcome assessed by the modified Rankin Scale (mRS) at 90 days and analysed using ordinal logistic regression in the intention-to-treat population. This trial is registered with EudraCT (2014-000096-80), ClinicalTrials.gov (NCT03181360), and ISRCTN (10601890).

FINDINGS

From June 12, 2017, to Sept 30, 2021, 578 of the required 600 patients were enrolled (288 randomly assigned to the tenecteplase group and 290 to the control group [intention-to-treat population]). The median age of participants was 73·7 years (IQR 65·9-81·1). 332 (57%) of 578 participants were male and 246 (43%) were female. Treatment with tenecteplase was not associated with better functional outcome, according to mRS score at 90 days (adjusted OR 1·18, 95% CI 0·88-1·58; p=0·27). Mortality at 90 days did not significantly differ between treatment groups (28 [10%] patients in the tenecteplase group and 23 [8%] in the control group; adjusted HR 1·29, 95% CI 0·74-2·26; p=0·37). Symptomatic intracranial haemorrhage occurred in six (2%) patients in the tenecteplase group versus three (1%) in the control group (adjusted OR 2·17, 95% CI 0·53-8·87; p=0·28), whereas any intracranial haemorrhage occurred in 33 (11%) versus 30 (10%) patients (adjusted OR 1·14, 0·67-1·94; p=0·64).

INTERPRETATION

In patients with wake-up stroke selected with non-contrast CT, treatment with tenecteplase was not associated with better functional outcome at 90 days. The number of symptomatic haemorrhages and any intracranial haemorrhages in both treatment groups was similar to findings from previous trials of wake-up stroke patients selected using advanced imaging. Current evidence does not support treatment with tenecteplase in patients selected with non-contrast CT.

FUNDING

Norwegian Clinical Research Therapy in the Specialist Health Services Programme, the Swiss Heart Foundation, the British Heart Foundation, and the Norwegian National Association for Public Health.

498 Improving Surgical and Non-Surgical Oncological Outcomes in Patients with Head and Neck Cancer

Introduction

Treatment of head and neck cancer is complex and involves a multi-disciplinary approach between surgeons and oncologists. Radiotherapy often leaves patients with debilitating side effects such as mucositis, sialadenitis and dysphagia. Radiation induces double strand breaks (DSBs) in DNA within both normal squamous cells and squamous cell carcinomas (SCCs) that, if left unrepaired, initiates programmed cell death. Like normal squamous cells, SCC’s have an effective DNA repair pathway to protect against apoptosis by repairing DSBs through proteins such as FanD2-S331. This study aims to show that mild hyperthermia inhibits FancD2, therefore having the potential to increase the susceptibility of SCCs to radiotherapy and subsequently reducing the side effects.

Method

Head and neck cancer cell line UMSCC47 was cultured, then irradiated with 2 Gray before washing with an anti γH2AX antibody, used as a biomarker for DSBs. Fluorescent antibodies against FacD2-S331 were then used to assess the levels present within the nucleus of cells exposed to mild hyperthermia (39 °C) and then compared to untreated cells and cells exposed to radiation only.

Results

A γH2AX fluorophore intensity score of 58 following radiation compared to 20 in the control confirmed the presence of DSBs. A FancD2-s331 fluorophore intensity score of 76 was observed in cells exposed radiation. Cells exposed to heat prior to radiation showed a FancD2-s331 fluorophore score of 21.

Conclusions

Exposure of SCCs to mild hyperthermia before radiotherapy reduces activation of DNA repair protein FancD2-S2331. A reduction in DNA repair increases the susceptibility of SCCs to radiotherapy and apoptosis.

72 Increasing Radiotherapy Induced DNA Damage by Inhibiting Repair Proteins

Introduction

Fanconi anaemia (FA) is a rare genetic disorder displaying higher incidences of head and neck squamous cell carcinoma (SCC). The surgical excision of these cancers is challenging and often supplemented with radiotherapy. One novel concept to improve survival rates is to increase the susceptibility of SCCs to radiotherapy. ATR is a protein responsible for homologous recombination repair (HRR) within the FA pathway and has been identified as a possible target for cancer therapy. Inhibition of ATR induces subsequent DNA damage. The primary objective of this study was to identify whether the inhibition of ATR can be achieved by exposing SCCs to mild hyperthermia. This novel concept aims to improve survival rates of patients with SCCs who require surgical excision and subsequent radiotherapy.

Method

By using a HRR assay it was possible to examine levels of DNA repair in various SCC cell lines following the exposure to radiation. These were compared to cells treated with heat, an ATR inhibitor and a mixture of both to determine whether heat reduces HRR.

Results

Repeated HRR assay’s showed SCC’s treated with heat, ATR inhibitor and a mixture of both before exposure to radiation underwent significantly lower levels of HRR compared to cells within the control.

Conclusions

Reduced HRR following exposure to heat increases the susceptibility of SCCs to radiotherapy. It is hoped that in combination with the surgical excision, this study will help to improve the outcomes of patients with head and neck carcinomas by improving the efficacy of radiotherapy.

The interaction between wheat roots and soil pores in structured field soil

Wheat (Triticum aestivum L.) root growth in the subsoil is usually constrained by soil strength, although roots can use macropores to elongate to deeper layers. The quantitative relationship between the elongation of wheat roots and the soil pore system, however, is still to be determined. We studied the depth distribution of roots of six wheat varieties and explored their relationship with soil macroporosity from samples with the field structure preserved. Undisturbed soil cores (to a depth of 100 cm) were collected from the field and then non-destructively imaged using X-ray computed tomography (at a spatial resolution of 90 µm) to quantify soil macropore structure and root number density (the number of roots cm-2 within a horizontal cross-section of a soil core). Soil macroporosity changed significantly with depth but not between the different wheat lines. There was no significant difference in root number density between wheat varieties. In the subsoil, wheat roots used macropores, especially biopores (i.e. former root or earthworm channels) to grow into deeper layers. Soil macroporosity explained 59% of the variance in root number density. Our data suggested that the development of the wheat root system in the field was more affected by the soil macropore system than by genotype. On this basis, management practices which enhance the porosity of the subsoil may therefore be an effective strategy to improve deep rooting of wheat.

Emergent Protective Organogenesis in Date Palms: A Morpho-Devo-Dynamic Adaptive Strategy during Early Development

Desert plants have developed mechanisms for adapting to hostile desert conditions, yet these mechanisms remain poorly understood. Here, we describe two unique modes used by desert date palms (Phoenix dactylifera) to protect their meristematic tissues during early organogenesis. We used x-ray micro-computed tomography combined with high-resolution tissue imaging to reveal that, after germination, development of the embryo pauses while it remains inside a dividing and growing cotyledonary petiole. Transcriptomic and hormone analyses show that this developmental arrest is associated with the low expression of development-related genes and accumulation of hormones that promote dormancy and confer resistance to stress. Furthermore, organ-specific cell-type mapping demonstrates that organogenesis occurs inside the cotyledonary petiole, with identifiable root and shoot meristems and their respective stem cells. The plant body emerges from the surrounding tissues with developed leaves and a complex root system that maximizes efficient nutrient and water uptake. We further show that, similar to its role in Arabidopsis (Arabidopsis thaliana), the SHORT-ROOT homolog from date palms functions in maintaining stem cell activity and promoting formative divisions in the root ground tissue. Our findings provide insight into developmental programs that confer adaptive advantages in desert plants that thrive in hostile habitats.

Methane transport in agricultural soil after injection of isotopically-enriched methane in the sub-surface

Small quantities of radioactive methane (¹⁴CH₄) may be released over prolonged periods from geological disposal facilities for radioactive waste. The impact of this release depends on the capacity of soil to oxidise ¹⁴CH₄ to ¹⁴CO₂ during transport from the sub-surface to the atmosphere. We investigated this capacity by pulse-injecting isotopically-enriched methane 50 cm below the surface of an agricultural soil in central England. Three sequential injections were made during growth of a spring wheat crop. Samples of gas were taken from the pore space throughout the soil profile at predetermined time points after injection, accompanied by samples of the atmosphere above the soil collected in sampling chambers, deployed at scheduled intervals. Methane and CO₂ were measured in soil and above-ground gas using gas chromatography; the isotopic composition of CH₄ and CO₂ was determined using gas chromatography with isotopic ratio mass spectrometry. Supporting measurements of environmental variables were made during the experiment. The data can be used to test mathematical models describing CH₄ and CO₂ transport and fate in temperate agricultural soils.

Non-fatal case of Crimean-Congo haemorrhagic fever imported into the United Kingdom (ex Bulgaria), June 2014

Crimean-Congo haemorrhagic fever (CCHF) was diagnosed in a United Kingdom traveller who returned from Bulgaria in June 2014. The patient developed a moderately severe disease including fever, headaches and petechial rash. CCHF was diagnosed following identification of CCHF virus (CCHFV) RNA in a serum sample taken five days after symptom onset. Sequence analysis of the CCHFV genome showed that the virus clusters within the Europe 1 clade, which includes viruses from eastern Europe.

Quantifying (12/13)CH(4) migration and fate following sub-surface release to an agricultural soil

Following gas generation in a Geological Disposal Facility (GDF), (14)C-containing gases could migrate through the geosphere, eventually diffusing into soils at the Earth's surface. This paper reports summary results from laboratory and field experiments to obtain information on the probable rates of a) diffusive transport and b) oxidation of (12/13)CH(4) (as a surrogate for (14)CH4) in a typical agricultural soil in the UK. Rates of CH(4) oxidation were generally low in the field and undisturbed soil columns, though a re-packed column of homogenised topsoil oxidised ambient atmospheric CH(4) 20× faster than an undisturbed soil column. In contrast to low observed rates of CH(4) oxidation, the effective diffusion of CH(4) through the soil was rapid. Isotopically labelled CH(4) injected at a depth of 45 cm in the field diffused to the surface and exited the soil over a time period ranging from 8 to 24 h. The rate of CH(4) diffusion through the soil was increased by the presence of ryegrass roots which increased soil porosity and decreased water content. δ(13)C values for laboratory column soils after labelled CH(4) injection experiments showed no sign of residual (13)C, despite the extremely high δ(13)C values of the injected (12/13)CH(4). If laboratory observations are confirmed by measurements in field samples it can be concluded that the majority of (14)CH(4) from a GDF which enters a soil with low methanotrophic activity will be lost to the free atmosphere after diffusing rapidly through the soil column.

Pet rats as a source of hantavirus in England and Wales, 2013

We report the detection of a strain of Seoul hantavirus (SEOV) in pet rats in England and Wales. The discovery followed an investigation of a case of haemorrhagic fever with renal syndrome in Wales. Hantavirus RNA was detected via real-time reverse transcription-polymerase chain reaction (RT-PCR) and classic RT-PCR in pet rats belonging to the patient. Sequencing and phylogenetic analysis confirmed the virus to be a SEOV that is similar, but not identical, to a previously reported United Kingdom strain from wild rats.

The continued emergence of hantaviruses: isolation of a Seoul virus implicated in human disease, United Kingdom, October 2012

Following a suspected case of hantavirus in a patientsuffering from acute kidney injury, rodents fromthe patient’s property in Yorkshire and the Humber,United Kingdom (UK) were screened for hantaviruses.Hantavirus RNA was detected via RT-PCR in two Rattusnorvegicus. Complete sequencing and phylogeneticanalysis established the virus as a Seoul hantavirus,which we have provisionally designated as strainHumber. This is the first hantavirus isolated from wildrodents in the UK and confirms the presence of a pathogenicSeoul virus in Europe.

The continued emergence of hantaviruses: isolation of a Seoul virus implicated in human disease, United Kingdom, October 2012

Binary file ES_Abstracts_Final_ECDC.txt matches

Sequencing and phylogenetic characterisation of a fatal Crimean - Congo haemorrhagic fever case imported into the United Kingdom, October 2012

A patient with fever, and haemorrhagic symptoms was admitted to a hospital in Glasgow on 2 October 2012. Since he had returned from Afghanistan, serum samples were sent for diagnosis at the Rare and Imported Pathogens Laboratory, where a real-time reverse transcriptase-PCR diagnosis of Crimean – Congo haemorrhagic fever was made within 3 hrs after receipt of the sample. Hereafter the patient was transferred to a high-security infectious diseases unit in London but died on 6 October.

Sequencing and phylogenetic characterisation of a fatal Crimean – Congo haemorrhagic fever case imported into the United Kingdom, October 2012

Binary file ES_Abstracts_Final_ECDC.txt matches

Treatment of poor-risk metastatic renal carcinoma patients with combination gemcitabine, capecitabine, and bevacizumab at a tertiary cancer center

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Background: Treatment of poor risk metastatic renal carcinoma (mRCC) is challenging, and empiric combinations may be attempted in practice once conventional therapies fail. These combinations may lead to formal clinical trials. Evaluation of mRCC patients given an empiric combination of gemcitabine (gem) capecitabine (cap), and bevacizumab (bev) at a tertiary care center was performed. Methods: After obtaining IRB approval, non investigational use of gem in combination with cap and bev in mRCC patients was identified using institutional databases. Collected data included demographics, previous therapies, number of metastatic sites, MSKCC risk stratification variables, prior nephrectomy status, drug therapy duration, and progression-free survival (PFS). Descriptive statistics were employed for data analysis. Results: Thirty-six patients were included in the analysis, with a median age of 55.5 years. Seventeen patients (47%) had previously received a tyrosine kinase inhibitor (TKI). Twenty-two patients (61%) had clear cell histology, 13 patients (36%) had sarcomatoid features, 20 patients (56%) had undergone previous nephrectomy, 20 patients (56%) had four or more sites of metastasis and 27 patients (75%) were diagnosed within 1 year of therapy. Initial treatment consisted of gem (908.61 mg/m2) every 2 weeks, cap (2.75 grams/day), and bev (828.82 mg) every 2 weeks. The median PFS for the study population was 5.83 months. The subset of TKI patients had a median PFS of 5.4 months. Therapy was relatively well tolerated with only 3 patients discontinuing one or more of the drugs due to adverse reactions. Thirteen of the patients started a TKI post discontinuation of the triple therapy. Conclusions: The triple therapy combination in this retrospective evaluation provides promising efficacy and acceptable tolerability in patients with poor prognosis mRCC. Based on these observations, a phase II is now underway assessing gemcitabine, capecitabine and becacizumab in patients with sarcomatoid RCC.

[Table: see text]

Patient characteristics associated with dose-limiting sunitinib adverse events

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Background: Sunitinib, an inhibitor of multiple tyrosine kinases, is FDA approved for metastatic renal cell cancer (mRCC). Though better tolerated than historical therapies, sunitinib is associated with adverse events (AEs) that may require dose modifications (DM). We sought to identify 1) baseline patient (pt) characteristics that predispose for DM, 2) the most common AEs requiring DM in a non-protocol setting, and 3) the impact of dose limiting AEs on treatment continuation. Methods: Single-center, retrospective chart review. Pts ≥ 18 years of age with mRCC of clear-cell histology on sunitinib therapy with active follow-up at MDACC were eligible. Univariate and multivariate logistic regression analysis of 66 pt variables (demographics, laboratory analysis, past medical and treatment history, etc) and dose-limiting AEs was completed, with a 6 month endpoint of sunitinib continuation, alternative therapy, or death. Results: From January 1, 2006 through September 30, 2007, 146 pts were identified meeting eligibility criteria. By univariate analysis, increased age (p=0.04; OR 1.04, 1.002–1.081 CI) and elevated BUN (p=0.03; OR 1.06, 1.006 –1.108 CI) were directly associated with increased incidence of dose-limiting AEs. ECOG PS of 2 (p=0.04; OR 0.3, 0.114–0.951 CI) was associated with a decreased incidence of dose limiting AEs. In a multivariate analysis, only BUN remained significant. 57% of patients (n= 83) had dose-limiting AEs. DM were often attributed to multiple AEs (55%), with fatigue, mucositis, hand-foot syndrome and nausea being the most common. At 6 months follow-up, 63% of pts with dose-limiting AEs remained on sunitinib vs. 37% (p=0.18). There was no difference in death rate at 6 months between the two groups. Conclusions: Elevated baseline BUN is associated with an increased rate of DM in patients with RCC receiving sunitinib. Despite the high-incidence of AEs, pts can be maintained on sunitinib with DM and without an adverse impact on outcome. Whether specific AEs are biologic indicators of activity should be evaluated in a larger clinical trial.

[Table: see text]

Treatment of pituitary-dependent Cushing's disease with the multireceptor ligand somatostatin analog pasireotide (SOM230): a multicenter, phase II trial

CONTEXT

There is currently no medical therapy for Cushing's disease that targets the pituitary adenoma. Availability of such a medical therapy would be a valuable therapeutic option for the management of this disorder.

OBJECTIVE

Our objective was to evaluate the short-term efficacy of the novel multireceptor ligand somatostatin analog pasireotide in patients with de novo, persistent, or recurrent Cushing's disease.

DESIGN

We conducted a phase II, proof-of-concept, open-label, single-arm, 15-d multicenter study.

PATIENTS

Thirty-nine patients with either de novo Cushing's disease who were candidates for pituitary surgery or with persistent or recurrent Cushing's disease after surgery without having received prior pituitary irradiation.

INTERVENTION

Patients self-administered sc pasireotide 600 microg twice daily for 15 d.

MAIN OUTCOME MEASURE

Normalization of urinary free cortisol (UFC) levels after 15 d treatment was the main outcome measure.

RESULTS

Of the 29 patients in the primary efficacy analysis, 22 (76%) showed a reduction in UFC levels, of whom five (17%) had normal UFC levels (responders), after 15 d of treatment with pasireotide. Serum cortisol levels and plasma ACTH levels were also reduced. Steady-state plasma concentrations of pasireotide were achieved within 5 d of treatment. Responders appeared to have higher pasireotide exposure than nonresponders.

CONCLUSIONS

Pasireotide produced a decrease in UFC levels in 76% of patients with Cushing's disease during the treatment period of 15 d, with direct effects on ACTH release. These results suggest that pasireotide holds promise as an effective medical treatment for this disorder.

The role of ITAM- and ITIM-coupled receptors in platelet activation by collagen

The major activation-inducing collagen receptor glycoprotein VI (GPVI) has been cloned within the last two years. It is a member of the Ig superfamily of proteins and is constitutively associated with the ITAM-bearing Fc receptor gamma-chain (FcR gamma-chain). GPVI signals through a pathway that involves several of the proteins used by Fc, B- and T-lymphocyte receptors and which takes place in glycolipid-enriched membrane domains in the plasma membrane known as GEMs. Responses to GPVI are regulated by PECAM-1 (CD31) and possibly other ITIM-bearing receptors. Despite a pivotal role for GPVI, there are important differences between signalling events to collagen and GPVI-specific ligands. This may reflect a role for co-receptors in the response to collagen.

The effects of tubulin-binding agents on stretch-induced ventricular arrhythmias

Stretch-activated ion channels have been identified as transducers of mechanoelectric coupling in the heart, where they may play a role in arrhythmogenesis. The role of the cytoskeleton in ion channel control has been a topic of recent study and the transmission of mechanical stresses to stretch-activated channels by cytoskeletal attachment has been hypothesized. We studied the arrhythmogenic effects of stretch in 16 Langendorff-perfused rabbit hearts in which we pharmacologically manipulated the microtubular network of the cardiac myocytes. Group 1 (n=5) was treated with colchicine, which depolymerizes microtubules, and Group 2 (n=6) was treated with taxol, which polymerizes microtubules. Stretch-induced arrhythmias were produced by transiently increasing the volume of a fluid-filled left ventricular balloon with a volume pump driven by a computer-controlled stepper motor. Electrical events were recorded by a contact electrode which provided high-fidelity recordings of monophasic action potentials and stretch-induced depolarizations. The probability of eliciting a stretch-induced arrhythmia increased (0.22+/-0.11 to 0.62+/-0.19, p=0.001) in hearts treated with taxol (5 microM), whereas hearts treated with colchicine (100 microM) showed no statistically significant change. We conclude that proliferation of microtubules increased the arrhythmogenic effect of transient left ventricle diastolic stretch. This result indicates a possible mode of arrhythmogenesis in chemotherapeutic patients and patients exhibiting uncompensated ventricular hypertrophy. The data would indicate that the cytoskeleton represents a possible target for antiarrhythmic therapies.

Correlation between human immunodeficiency virus genotypic resistance and virologic response in patients receiving nelfinavir monotherapy or nelfinavir with lamivudine and zidovudine

The relationship between detectable human immunodeficiency virus (HIV) genotypic resistance and virologic response was compared in patients receiving nelfinavir as monotherapy (16 weeks) or in combination with lamuvidine and zidovudine (48 weeks). Two patient groups were defined on the basis of the presence or absence of substitutions associated with nelfinavir, a protease (PR) inhibitor, and/or a reverse transcriptase (RT) inhibitor. HIV RNA levels <50 copies/mL were achieved in 17 (85%) of 20 combination-therapy patients without genotypic resistance (PR-RT(-)) versus only 1 (17%) of 6 patients with genotypic resistance (PR-RT(+)). PR-RT(-) patients exhibited greater and more durable virus suppression compared with PR-RT(+) patients. All 6 PR-RT(+) patients had virus with M184V (lamuvidine resistance); 3 isolates also contained D30N (nelfinavir resistance). M184V preceded D30N in all determinable instances. In this study, suppression of HIV replication to <50 copies/mL was associated with durable response and reduced incidence of resistance. Results also indicate that combination regimens can fail despite the absence of detectable genotypic PR resistance.

Minimal evidence of platelet and endothelial cell reactive antibodies in thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is a syndrome characterized by microvascular thrombosis with thrombocytopenia and end-organ injury. Evidence suggests that platelet or endothelial cell injury may be initial pathological events in TTP. A number of factors in patient plasma, including immunoglobulins, have been proposed to mediate cellular injury in TTP. However, systematic analyses of TTP patient plasma for the presence of platelet or endothelial cell antibodies are lacking. We, therefore, analyzed 48 TTP patient plasma samples for the presence of platelet and endothelial cell antibodies by using enzyme-linked immunosorbent assay, flow cytometry, and microlymphocytotoxicity. Twelve of 48 TTP patient samples (25%) reacted against purified platelet glycoproteins. Nine (19%) also contained antibodies that bound to allogeneic target platelets in flow-cytometric assays. Nine of 48 samples (19%) contained antibodies to human umbilical vein endothelial cells in flow-cytometric assays, and seven of 48 patient samples (15%) bound to human dermal microvascular endothelial cells. Six of 48 (13%) patient plasma samples contained antibodies that bound to human umbilical vein endothelial cells activated with gamma-interferon and tumor necrosis factor-alpha. Of twenty samples that were reactive in one or more platelet or endothelial cell assay, eight contained human leukocyte antigen antibodies reactive in microlymphocytotoxicity. These studies demonstrate that antibodies reactive against platelet or endothelial cell antigens are not prevalent in TTP, and that more than a third of antibodies detected are human leukocyte antigen alloantibodies. Our findings suggest that autoantibodies against platelets or endothelial cells are not important in the pathogenesis of this syndrome.

Infected macaques that controlled replication of SIVmac or nonpathogenic SHIV developed sterilizing resistance against pathogenic SHIV(KU-1)

Twenty macaques were used to evaluate the ability of nonpathogenic SIV(mac) or nonpathogenic chimeric SIV-HIV (SHIV) to induce protection in macaques against superinfection with a pathogenic variant of SHIV (SHIV(KU-1)) originally containing the tat, rev, vpu, and env of HIV-1 (strain HXB2) in a genetic background of SIV(mac)239. Specifically, three macaques inoculated with molecularly cloned, macrophage-tropic SIV(mac)LG1 developed an early systemic infection but recovered with only traces of SIV(mac) DNA in visceral lymphoid tissues. These animals were then inoculated parenterally with pathogenic SHIV(KU-1). All three animals resisted infection with SHIV(KU-1), as indicated by lack of virus recovery and absence of SHIV-specific env and vpu sequences in the visceral lymphoid tissues and multiple regions in the CNS. We also examined the ability of five macaques that had been inoculated with nonpathogenic SHIV (NP-SHIV) to withstand challenge with the pathogenic SHIV(KU-1). Like the SIV(mac)LG1-inoculated macaques, these animals also resisted SHIV(KU-1) challenge as judged by the inability to recover infectious virus, normal CD4+ T cell counts, and the absence of SHIV(KU-1) signature sequences in the lymph node tissue. Thus, eight of eight animals that developed control over primary lentivirus infections had also developed resistance to infection with pathogenic SHIV(KU-1). Three groups of macaques were used as controls for this study. The first group consisted of six macaques inoculated with SHIV(KU-1) alone. All animals developed viremia, showed severe loss of CD4+ T cells within 4 weeks, and succumbed to AIDS within 6 months. The second group of three macaques was inoculated first with SHIV(KU-1) and inoculated later with uncloned, neurovirulent SIV(mac)7F-Lu. A third group of three macaques was inoculated with SIV(mac)7F-Lu followed by inoculation with SHIV(KU-1). PCR analyses using oligonucleotide primers specific for the SIV or HIV env revealed that macaques from the last two groups had widespread infection with both SHIV(KU-1) and SIV(mac), indicating that animals that failed to control productive replication of either SHIV(KU-1) or SIV(mac)7F-Lu could not resist superinfection with the other virus. These data indicate that sterilizing immunity against the virulent SHIV could be induced in animals that had experienced an immunizing infection. Moreover, the divergence of the envelope glycoprotein of the protective avirulent and virulent challenge virus suggests that a single vaccine could protect against infection with a virus containing a different envelope glycoprotein.

A cell-free stock of simian-human immunodeficiency virus that causes AIDS in pig-tailed macaques has a limited number of amino acid substitutions in both SIVmac and HIV-1 regions of the genome and has offered cytotropism

We have examined both the sequence changes in the LTR, gag, vif, vpr, vpx, tat, rev, vpu, env, and nef genes and the cell tropism of a cell-free stock of chimeric simian-human immunodeficiency virus (SHIV) isolated from the cerebrospinal fluid of a pig-tailed macaque (PNb) that developed AIDS. This virus (SHIVKU-1) is highly pathogenic when inoculated into other macaques. DNA sequence analysis of PCR-amplified products revealed a total of 5 nucleotide changes in the LTR while vif had 2 consensus amino acid changes. The gag, vif, and vpx had no consensus amino acid substitutions, whereas vpr had 1 consensus substitution. The tat and rev genes of the HXB2 region of SHIVKU-1 had 2 and 1 consensus amino acid changes, respectively. The vpu gene of the HXB2 region of SHIV, which originally had an ACG at the beginning of the gene, reverted to an initiation ATG codon and in addition contained a consensus amino acid substitution at position 69 of this protein. As expected, the majority of the nucleotide substitutions were found in the env and nef genes. Thirteen and 5 amino acid changes were predicted for the corresponding Env and Nef proteins, respectively. In addition, one-third of the env gene clones isolated from the SHIVKU-1 stock had a 5-amino-acid deletion in the V4 region. Using three independent assays, we determined that the changes in the SHIVKU-1 were associated with an increase in the efficiency of replication in macrophages. The strikingly few consensus changes in the virus suggest that conversion of this virus to one capable of causing AIDS in pig-tailed macaques was associated with relatively few changes in the viral envelope and/or accessory genes. These results will provide the basis for the development of a pathogenic, molecular clone of SHIV capable of causing AIDS in pig-tailed macaques.

Modulation of cranial bone healing with a heparin-like dextran derivative

Substituted dextran polymers have been shown to bind growth factors and protect them from enzymatic degradation. Using this information, other researchers have been able to use these substituted dextrans to enhance the healing of bone in an environment where bone would otherwise not regenerate. We used substituted dextran polymers to evaluate their ability to accelerate the healing of cranial bone in a rabbit model. We were able to document a more rapid rate of healing and demonstrate micrographic evidence to support that conclusion. Possible mechanisms are postulated.

Computer-assisted image analysis of tumor sections for a new thrombospondin receptor

BACKGROUND

A cell surface receptor (50 kd) has been recently identified in malignant cells that recognizes the tumor cell adhesive domain (ie, cysteine-serine-valine-threonine-cysteine-glycine [CSVTCG]) of thrombospondin (TSP). This CSVTCG-specific TSP receptor can be considered as a new tumor marker, and its concentration on the cell surface may correlate directly with the capacity of tumor cells to invade and metastasize.

MATERIALS AND METHODS

Six patients with primary, stages III and IV squamous cell carcinomas of the head and neck were studied. Tumor sections were specifically stained for this receptor with immunohistochemical techniques. The stained specimens were then subjected to computer-assisted image analysis. The area of positive staining and the heterogeneity of the pattern of staining were compared to peritumoral angiogenesis and clinical outcome of the patients.

RESULTS

The results indicate that those patients with a high and homogenous positive stain score (mean +/- standard error [SE] 78 +/- 5%) for the CSVTCG-specific TSP receptor had high microvessel density and died from metastatic disease within 12 months of initial treatment (correlation coefficients = 0.95 and 1, respectively). Patients with a low and heterogenous positive stain score for receptor (mean +/- SE 8 +/- 2%; P < 0.001) had low microvessel counts and remained disease-free for at least 2 years. There was no relationship between receptor density and histologic classification of the primary tumors.

CONCLUSION

The CSVTCG-specific TSP receptor, quantified through image analysis of immunohistochemical stained tissue sections, is highly predictive of clinical outcome in patients with squamous cell carcinomas of the head and neck.

The relationship of angiogenesis to biological activity in human squamous cell carcinomas of the head and neck

Tumor angiogenesis has recently been related to tumor growth and metastasis, which determine the clinical outcome of the patient. This study was designed to determine the relationship between angiogenesis in primary squamous cell carcinomas (SCC) of the head and neck and the development of recurrent or metastatic disease, or both. Different SCC of the head and neck were studied. Microvessels were selectively stained using a monoclonal antibody for factor VIII. Microvessel counts were performed in the tumor, in the tissues immediately adjacent, and in normal tissues of similar topographies. Microvessel counts were then correlated with clinical outcome (development of recurrent or metastatic disease, or both). Recurrent or metastatic disease, or both, developed in patients with high microvessel counts (mean, 121.25) in the tissues adjacent to the tumor 7 to 16 months after initial treatment. Those with low microvessel counts (mean, 33.75) were disease-free for 16 months to 6 years (p < 0.01). Microvessel counts inside the tumor were also higher in those in whom recurrences or metastasis, or both, developed, but were not statistically significant. In this study, angiogenesis was directly related to clinical outcome. Thus, angiogenesis may be an independent predictor of recurrent or metastatic disease, or both, which could help in the selection of patients with SCC of the head and neck for aggressive therapy.

A response to the British Paediatric Association report on paediatric intensive care services

The publication of the long-awaited report by the British Paediatric Association (BPA) (1993) in conjunction with the Department of Health (DoH) has added yet another dimension to the already complex problem of providing comprehensive intensive care services.

Persistence of sham feeding after intragastric meals in rats

In rats on a stringent deprivation schedule and at reduced body weight, an intragastric load of liquid diet that equals or exceeds normal meal size has no effect at all on subsequent sham feeding of milk diet or of glucose. Removing the acute deprivation period and reversing, or preventing, severe weight reduction has no effect on this "persistence" of sham feeding: a full intragastric meal may leave sham feeding quite unaffected, even if that meal follows the previous meal at a physiological interval, in rats at normal weight. These data contrast with graded, dose-dependent effects of other manipulations by other investigators. Perhaps such effects depend on conditioned or anticipatory controls of feeding, whereas our findings apply to unconditioned controls.

Differences in antigen expression between neoplastic and nonneoplastic gallbladder epithelium. An immunohistochemical study

Immunoreactivity for a panel of 15 monoclonal antibodies (MAbs), which are known to react with different gastrointestinal tumor antigens, was assessed in formalin-fixed paraffin-embedded sections that were prepared from cholecystectomy specimens obtained from Mexican patients. Each case was classified histologically into one of the following groups: (1) invasive adenocarcinoma (N = 21), (2) high-grade dysplasia (carcinoma in situ) (N = 2), (3) low-grade dysplasia (N = 4), hyperplasia (4) (N = 15), and (5) chronic cholecystitis (N = 10). Significant differences (P < 0.05) were identified among the five histopathologic groups in the proportion of epithelial cells demonstrating immunoreactivity with MAbs to Lewisb; Lewis(a); sialylated Lewis(a); sialylated Lewis(a) and Lewis(a); Y antigen; H antigen; X antigen; X-like antigen; 200-kDa protein of CEA; 180-, 160-, 50-, 40-kDa proteins of CEA; 30- to 37-kDa protein; and an undefined antigen identified by MAb 99-57, with invasive carcinoma more frequently being positive as compared to nonneoplastic (hyperplasia, chronic cholecystitis) epithelium. Significant differences were also observed among the five histopathologic groups (P < or = 0.0005) in the proportion of epithelial cells demonstrating immunoreactivity with MAbs to Y antigen and the 20- to 50-kDa glycoprotein. However, with these two antibodies immunoreactivity was more frequently found in nonneoplastic epithelium rather than in invasive carcinomas. No significant differences in immunoreactivity were detected among the different histologic groups with MAb to blood group B antigen, types 1 and 2. This study demonstrates that cellular antigens are both developed and lost during the process of neoplastic transformation in the gallbladder.(ABSTRACT TRUNCATED AT 250 WORDS)

A prospective study of pulmonary function and gas exchange following liver transplantation

Pulmonary function and gas exchange were prospectively studied in 95 patients before and 9 to 15 months following liver transplantation. Pretransplant, the most common PF abnormality was impaired efficiency of gas exchange as measured by Dss. As a group, the mean Dss was 78.0 +/- 16.6 percent predicted and was found to be less than 80 percent predicted in 50 patients. As a group, patients with the most severe liver diseases clinically (Child's C classification) had the lowest mean Dss pretransplant. Posttransplant, three findings were of clinical importance: PaCO2 significantly improved posttransplantation, suggesting a resolution of pretransplant respiratory alkalosis. Expiratory airflow obstruction, measured by a change in the FEV1/FVC, was extremely uncommon posttransplant. Mean Dss improved significantly in patients with Child's C severity of liver disease. The most frequent deteriorations in Dss statistically were associated with posttransplant thoracotomy, ARDS, nonspecific pneumonitis, significant pleural effusions and hepatic retransplantation.

Two antigens detected on human ocular melanomas with the mouse monoclonal antibodies 2/10SN and 10/12SN

Seven human ocular melanoma cell lines were established in vitro and 3 of these, GU-4, LLN-40 and its subline C17-11, were characterized. Mice were immunized with these ocular melanoma cell lines, and 2 hybridomas producing monoclonal IgG1 antibodies (MAb) were produced. MAb 2/10SN recognizes a 44-kDa monomeric protein, whereas MAb 10/12SN reacts with an 83/65-kDa heterodimeric protein. These melanoma-associated antigens (MAA) are detected at high concentrations in the cytoplasm of ocular melanoma cells. However, cell-surface labelling techniques suggest that these MAA are also associated with the cell-surface membrane. These 2 ocular MAA are also expressed by several skin melanoma cell lines. Immunohistochemical studies have localized these antigens to ocular and skin melanomas, to sweat ducts and basal squamous cells in normal skin, with limited expression in several other normal tissues and some carcinomas. Biodistribution studies in nude mice with human ocular melanomas have demonstrated good localization of 125I-labeled MAb 2/10SN at the tumor sites. Therefore, these 2 MAbs, 2/10SN and 10/12SN, recognize MAA which appear to be unique and may prove useful for imaging purposes.

Cutaneous responses to vasoactive intestinal polypeptide in chronic idiopathic urticaria

Cutaneous wheal and flare responses to increasing concentrations of calcitonin gene-related peptide, substance P, neurokinin A, vasoactive intestinal polypeptide (VIP), compound 48/80, and phosphate-buffered saline were measured in 10 patients with chronic idiopathic urticaria and 10 healthy controls. A significant increase in VIP-induced wheal, but not flare or cutaneous blood flow, was seen in urticarial patients compared with controls (p less than 0.001). No significant differences in responses to other tested compounds were found between these groups. These data point to an increased sensitivity of microvasculature to VIP in patients with chronic idiopathic urticaria.

Use of bacterial trpE fusion vectors to express and characterize the bovine immunodeficiency-like virus core protein

The gag coding region from Bovine Immunodeficiency-like Virus (BIV) was cloned into E. coli and expressed as a bacterial fusion protein. Six different clones spanning various regions of the gag open reading frame were generated. The resulting fusion proteins were expressed at high concentrations and readily purified. A panel of bovine immune sera specifically recognized the recombinant Gag proteins, as did immune sera from animals infected or immunized with lentiviruses related to BIV, such as Equine Infectious Anemia Virus (EIAV) and Human Immunodeficiency Virus (HIV). Analysis of the deletion clones, using the bovine immune sera panel, enabled us to identify at least one major epitope which was specifically recognized by all bovine sera examined. The ease of expression, purification, and specificity of these fusion proteins should enable a thorough study of the epidemiology of BIV infection.

Interaction of subtype-selective antagonists with alpha 1-adrenergic receptor-mediated second messenger responses in rat brain

The selective antagonists (+)-niguldipine and 5-methylurapidil (5-MU) were used to more clearly identify the alpha 1-adrenergic receptor subtypes involved in second messenger responses in slice and culture preparations of rat brain. The alpha 1-adrenergic receptor activating [3H]inositol phosphate (InsP) formation in neocortical and hippocampal slices appeared to have mixed characteristics. Although the low potency of (+)-niguldipine indicated involvement of the alpha 1B subtype, 5-MU had an alpha 1A-like potency at this subtype. (+)-Niguldipine did not inhibit the alpha 1 receptor-mediated potentiation of the cAMP response to either isoproterenol or adenosine in cortical slices, even at high concentrations. 5-MU inhibited both cAMP responses, although this inhibition appeared non-competitive. Thus, these receptors are clearly different from those mediating InsP formation. In primary glial cultures, (+)-niguldipine also had a low potency in blocking norepinephrine-stimulated [3H]InsP formation, consistent with involvement of the alpha 1B subtype. However, both 5-MU and WB 4101 had high potencies in blocking this response, suggesting involvement of the alpha 1A subtype. Inactivation of the alpha 1B subtype by pretreatment of cultures with chloroethylclonidine did not increase the potencies of any of these antagonists. The inhibition by 5-MU and WB 4101 was competitive in both control and chloroethylclonidine-pretreated cultures, whereas the inhibition by (+)-niguldipine was primarily noncompetitive. The use of these more selective antagonists shows that the current alpha 1A/alpha 1B subclassification scheme is inadequate to identify the receptors mediating these responses. None of the responses were blocked by (+)-niguldipine with the high potency expected at the alpha 1A subtype, although all InsP responses were blocked by 5-MU with a relatively high (alpha 1A-like) potency. In addition, very low affinity and noncompetitive effects of (+)-niguldipine were observed. These data raise the possibility of additional subtypes of alpha 1-adrenergic receptors or as yet unidentified functional interactions between known subtypes.

Constitutive expression of multiple growth factor genes by melanoma cells but not normal melanocytes

In a panel of metastatic melanoma cell lines we found steady-state mRNA transcripts for multiple growth factors including basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF)-A, PDGF-B, transforming growth factor (TGF)- beta 1, TGF- alpha, melanoma growth-stimulating activity (MGSA), interleukin (IL)-1 alpha, and IL-1 beta but not insulin-like growth factor (IGF)-1 or IGF-2. Expression of growth factor genes was constitutive because prior to RNA extraction melanoma cells were maintained in a chemically defined culture medium free of exogenous growth factors. Each of four cell lines had an individual pattern of expression of either two, four, five, or seven growth factors; however, all cell lines shared expression of the bFGF gene. Two strains of normal melanocytes expressed TGF- beta 1 but not bFGF, PDGF, TGF- alpha , or MGSA mRNA at detectable levels. We tested growth-modulatory effects of the growth factors most frequently expressed by melanoma cells (bFGF, TGF- alpha, TGF- beta, PDGF). None of these stimulated melanoma cell growth consistently, whereas exogenous, acid-activated TGF- beta inhibited melanoma growth at concentrations greater than 10 ng/ml, suggesting that bioactive TGF- beta may represent a physiologic growth inhibitor. Neither neutralizing antisera to PDGF or TGF- alpha nor a monoclonal antibody to the epidermal growth factor (EGF)-receptor inhibited melanoma cell growth. Our results indicate that multiple growth factors are expressed simultaneously and constitutively by melanoma cells but not normal melanocytes in culture. Expression of bFGF is a common feature underscoring the significance of bFGF as an autocrine factor for melanoma cells as described earlier. Secreted PDGF and TGF- alpha are apparently not involved in or not essential for autocrine growth stimulation of melanoma cells.