Synthesis and PET Imaging Biodistribution Studies of Radiolabeled Iododiflunisal, a Transthyretin Tetramer Stabilizer, Candidate Drug for Alzheimer's Disease

The small-molecule iododiflunisal (IDIF) is a transthyretin (TTR) tetramer stabilizer and acts as a chaperone of the TTR-Amyloid beta interaction. Oral administration of IDIF improves Alzheimer's Disease (AD)-like pathology in mice, although the mechanism of action and pharmacokinetics remain unknown. Radiolabeling IDIF with positron or gamma emitters may aid in the in vivo evaluation of IDIF using non-invasive nuclear imaging techniques. In this work, we report an isotopic exchange reaction to obtain IDIF radiolabeled with 18F. [19F/18F]exchange reaction over IDIF in dimethyl sulfoxide at 160 °C resulted in the formation of [18F]IDIF in 7 ± 3% radiochemical yield in a 20 min reaction time, with a final radiochemical purity of >99%. Biodistribution studies after intravenous administration of [18F]IDIF in wild-type mice using positron emission tomography (PET) imaging showed capacity to cross the blood-brain barrier (ca. 1% of injected dose per gram of tissue in the brain at t > 10 min post administration), rapid accumulation in the liver, long circulation time, and progressive elimination via urine. Our results open opportunities for future studies in larger animal species or human subjects.

[123I]CC1: A PARP-Targeting, Auger Electron-Emitting Radiopharmaceutical for Radionuclide Therapy of Cancer

Poly(adenosine diphosphate ribose) polymerase (PARP) has emerged as an effective therapeutic strategy against cancer that targets the DNA damage repair enzyme. PARP-targeting compounds radiolabeled with an Auger electron-emitting radionuclide can be trapped close to damaged DNA in tumor tissue, where high ionizing potential and short range lead Auger electrons to kill cancer cells through the creation of complex DNA damage, with minimal damage to surrounding normal tissue. Here, we report on [123I]CC1, an 123I-labeled PARP inhibitor for radioligand therapy of cancer. Methods: Copper-mediated 123I iododeboronation of a boronic pinacol ester precursor afforded [123I]CC1. The level and specificity of cell uptake and the therapeutic efficacy of [123I]CC1 were determined in human breast carcinoma, pancreatic adenocarcinoma, and glioblastoma cells. Tumor uptake and tumor growth inhibition of [123I]CC1 were assessed in mice bearing human cancer xenografts (MDA-MB-231, PSN1, and U87MG). Results: In vitro and in vivo studies showed selective uptake of [123I]CC1 in all models. Significantly reduced clonogenicity, a proxy for tumor growth inhibition by ionizing radiation in vivo, was observed in vitro after treatment with as little as 10 Bq [123I]CC1. Biodistribution at 1 h after intravenous administration showed PSN1 tumor xenograft uptake of 0.9 ± 0.06 percentage injected dose per gram of tissue. Intravenous administration of a relatively low amount of [123I]CC1 (3 MBq) was able to significantly inhibit PSN1 xenograft tumor growth but was less effective in xenografts that expressed less PARP. [123I]CC1 did not cause significant toxicity to normal tissues. Conclusion: Taken together, these results show the potential of [123I]CC1 as a radioligand therapy for PARP-expressing cancers.

Correlation between molar activity, injection mass and uptake of the PARP targeting radiotracer [18F]olaparib in mouse models of glioma

PURPOSE

Radiopharmaceuticals targeting poly(ADP-ribose) polymerase (PARP) have emerged as promising agents for cancer diagnosis and therapy. PARP enzymes are expressed in both cancerous and normal tissue. Hence, the injected mass, molar activity and potential pharmacological effects are important considerations for the use of radiolabelled PARP inhibitors for diagnostic and radionuclide therapeutic applications. Here, we performed a systematic evaluation by varying the molar activity of [18F]olaparib and the injected mass of [TotalF]olaparib to investigate the effects on tumour and normal tissue uptake in two subcutaneous human glioblastoma xenograft models.

METHODS

[18F]Olaparib uptake was evaluated in the human glioblastoma models: in vitro on U251MG and U87MG cell lines, and in vivo on tumour xenograft-bearing mice, after administration of [TotalF]olaparib (varying injected mass: 0.04-8.0 µg, and molar activity: 1-320 GBq/μmol).

RESULTS

Selective uptake of [18F]olaparib was demonstrated in both models. Tumour uptake was found to be dependent on the injected mass of [TotalF]olaparib (µg) but not the molar activity. An injected mass of 1 μg resulted in the highest tumour uptake (up to 6.9 ± 1.3%ID/g), independent of the molar activity. In comparison, both the lower and higher injected masses of [TotalF]olaparib resulted in lower relative tumour uptake (%ID/g; P < 0.05). Ex vivo analysis of U87MG xenograft sections showed that the heterogeneity in [18F]olaparib intratumoural uptake correlated with PARP1 expression. Substantial upregulation of PARP1-3 expression was observed after administration of [TotalF]olaparib (> 0.5 µg).

CONCLUSION

Our findings show that the injected mass of [TotalF]olaparib has significant effects on tumour uptake. Moderate injected masses of PARP inhibitor-derived radiopharmaceuticals may lead to improved relative tumour uptake and tumour-to-background ratio for cancer diagnosis and radionuclide therapy.

Bimodal Imaging of Mouse Peripheral Nerves with Chlorin Tracers

Almost 17 million Americans have a history of cancer, a number expected to reach over 22 million by 2030. Cancer patients often undergo chemotherapy in the form of antineoplastic agents such as cis-platin and paclitaxel. Though effective, these agents can induce debilitating side effects; the most common neurotoxic effect, chemotherapy-induced peripheral neuropathy (CIPN), can endure long after treatment ends. Despite the widespread and chronic nature of the dysfunction, no tools exist to quantitatively measure chemotherapy-induced peripheral neuropathy. Such a tool would not only benefit patients but their stratification could also save significant financial and social costs associated with neuropathic pain. In our first step toward addressing this unmet clinical need, we explored a novel dual approach to localize peripheral nerves: Cerenkov luminescence imaging (CLI) and fluorescence imaging (FI). Our approach revolves around the targeting and imaging of voltage-gated sodium channel subtype Na_V1.7, highly expressed in peripheral nerves from both harvested human and mouse tissues. For the first time, we show that Hsp1a, a radiolabeled Na_V1.7-selective peptide isolated from Homoeomma spec. Peru, can serve as a targeted vector for delivering a radioactive sensor to the peripheral nervous system. In situ, we observe high signal-to-noise ratios in the sciatic nerves of animals injected with fluorescently labeled Hsp1a and radiolabeled Hsp1a. Moreover, confocal microscopy on fresh nerve tissue shows the same high ratios of fluorescence, corroborating our in vivo results. This study indicates that fluorescently labeled and radiolabeled Hsp1a tracers could be used to identify and demarcate nerves in a clinical setting.

18F-meta-fluorobenzylguanidine (18F-mFBG) to monitor changes in norepinephrine transporter expression in response to therapeutic intervention in neuroblastoma models

Targeted radiotherapy with 131I-mIBG, a substrate of the human norepinephrine transporter (NET-1), shows promising responses in heavily pre-treated neuroblastoma (NB) patients. Combinatorial approaches that enhance 131I-mIBG tumour uptake are of substantial clinical interest but biomarkers of response are needed. Here, we investigate the potential of 18F-mFBG, a positron emission tomography (PET) analogue of the 123I-mIBG radiotracer, to quantify NET-1 expression levels in mouse models of NB following treatment with AZD2014, a dual mTOR inhibitor. The response to AZD2014 treatment was evaluated in MYCN amplified NB cell lines (Kelly and SK-N-BE(2)C) by Western blot (WB) and immunohistochemistry. PET quantification of 18F-mFBG uptake post-treatment in vivo was performed, and data correlated with NET-1 protein levels measured ex vivo. Following 72 h AZD2014 treatment, in vitro WB analysis indicated decreased mTOR signalling and enhanced NET-1 expression in both cell lines, and 18F-mFBG revealed a concentration-dependent increase in NET-1 function. AZD2014 treatment failed however to inhibit mTOR signalling in vivo and did not significantly modulate intratumoural NET-1 activity. Image analysis of 18F-mFBG PET data showed correlation to tumour NET-1 protein expression, while further studies are needed to elucidate whether NET-1 upregulation induced by blocking mTOR might be a useful adjunct to 131I-mIBG therapy.

Covid-19: implications for insurer risk management and the insurability of pandemic risk

This paper analyzes the insurability of pandemic risk and outlines how underwriting policies and scenario analysis are used to build resilience upfront and plan contingency actions for crisis scenarios. It then summarizes the unique "lessons learned" from the Covid-19 crisis by baselining actual developments against a reasonable, pre-Covid-19 pandemic scenario based on the 2002 SARS epidemic and 1918 Spanish influenza pandemic. Actual developments support the pre-Covid-19 hypothesis that financial market developments dominate claims losses due to the demographics of pandemics and other factors. However, Covid-19 "surprised" relative to the pre-Covid-19 scenario in terms of its impact on the real economy as well as on the property and casualty segment as business interruption property triggers and exclusions are challenged, something that may adversely impact the insurability of pandemics as well as the perception of the industry for some time to come. The unique lessons of Covid-19 reinforce the need for resilience upfront in solvency and liquidity, the need to improve business interruption wordings and re-underwrite the book, and the recognition that business interruption caused by pandemics may not be an insurable risk due to its large accumulation potential and the threat of external moral hazard. These insurability limitations lead to a discussion about the structure and financing of protection against the impact of future pandemics.

Improved radiosynthesis of 123I-MAPi, an auger theranostic agent

PURPOSE

123I-MAPi, a novel PARP1-targeted Auger radiotherapeutic has shown promising results in pre-clinical glioma model. Currently, 123I-MAPi is synthesized using multistep synthesis that results in modest yields and low molar activities (MA) that limits the ability to translate this technology for human studies where high doses are administered. Therefore, new methods are needed to synthesize 123I-MAPi in high activity yields (AY) and improved MA to facilitate clinical translation and multicenter trials.

MATERIALS AND METHODS

123I-MAPi was prepared in a single step via 123I-iododetannylation of the corresponding tributylstannane precursor. In vitro internalization assay, subcellular fractionation and confocal microscopy where used to evaluate the performance of 123I-MAPi in a small cell lung cancer model.

RESULTS

123I-MAPi was synthesized in a single step from the corresponding stannane precursor in AY of 45 ± 2% and MA of 11.8 ± 4.8 GBq µmol-1. In vitro in LX22 cells showed rapid internalization (5 min) with accumulation found predominantly in the membrane, nucleus and chromatin of the cell as determined by subcellular fractionation.

CONCLUSIONS

Here, we have developed an improved radiosynthesis of 123I-MAPi, an Auger theranostic agent. This process was achieved using a single step, 123I-iododestannylation reaction from the corresponding stannane precursor in good AY and MA. 123I-MAPi was evaluated in vitro in a small cell lung cancer model with high PARP expression, rapid internalization and high nuclear uptake shown.

A one-pot radiosynthesis of [18 F]PARPi

In this paper, we disclose a new strategy for the radiosynthesis of [¹⁸ F]PARPi from the corresponding, boc-protected, nitro-precursor. Using a two-step procedure, [¹⁸ F]PARPi could be isolated in radiochemical yields up to 9.6%. The reaction proceeds via an efficient one-pot, two-step process, allowing for simplification over previous methods that require complex multi-step, multi-pot strategies to be implemented.

Manual and automated Cu-mediated radiosynthesis of the PARP inhibitor [18F]olaparib

Positron emission tomography (PET) is a diagnostic nuclear imaging modality that relies on automated protocols to prepare agents labeled with a positron-emitting radionuclide (e.g., 18F). In recent years, new reactions have appeared for the 18F-labeling of agents that are difficult to access by applying traditional radiochemistry, for example those requiring 18F incorporation into unactivated (hetero)arenes. However, automation of these new methods for translation to the clinic has progressed slowly because extensive modification of manual protocols is typically required when implementing novel 18F-labeling methodologies within automated modules. Here, we describe the workflow that led to the automated radiosynthesis of the poly(ADP-ribose) polymerase (PARP) inhibitor [18F]olaparib. First, we established a robust manual protocol to prepare [18F]olaparib from the protected N-[2-(trimethylsilyl)ethoxy]methyl (SEM) arylboronate ester precursor in a 17% ± 5% (n = 15; synthesis time, 135 min) non-decay-corrected (NDC) activity yield, with molar activity (Am) up to 34.6 GBq/µmol. Automation of the process, consisting of copper-mediated 18F-fluorodeboronation followed by deprotection, was achieved on an Eckert & Ziegler Modular-Lab radiosynthesis platform, affording [18F]olaparib in a 6% ± 5% (n = 3; synthesis time, 120 min) NDC activity yield with Am up to 319 GBq/µmol.

Imaging of translocator protein upregulation is selective for pro-inflammatory polarized astrocytes and microglia

Translocator protein (TSPO) expression is increased in activated glia, and has been used as a marker of neuroinflammation in PET imaging. However, the extent to which TSPO upregulation reflects a pro- or anti-inflammatory phenotype remains unclear. Our aim was to determine whether TSPO upregulation in astrocytes and microglia/macrophages is limited to a specific inflammatory phenotype. TSPO upregulation was assessed by flow cytometry in cultured astrocytes, microglia, and macrophages stimulated with lipopolysaccharide (LPS), tumor necrosis factor (TNF), or interleukin-4 (Il-4). Subsequently, mice were injected intracerebrally with either a TNF-inducing adenovirus (AdTNF) or IL-4. Glial expression of TSPO and pro-/anti-inflammatory markers was assessed by immunohistochemistry/fluorescence and flow cytometry. Finally, AdTNF or IL-4 injected mice underwent PET imaging with injection of the TSPO radioligand 18 F-DPA-713, followed by ex vivo autoradiography. TSPO expression was significantly increased in pro-inflammatory microglia/macrophages and astrocytes both in vitro, and in vivo after AdTNF injection (p < .001 vs. control hemisphere), determined both histologically and by FACS. Both PET imaging and autoradiography revealed a significant (p < .001) increase in 18 F-DPA-713 binding in the ipsilateral hemisphere of AdTNF-injected mice. In contrast, no increase in either TSPO expression assessed histologically and by FACS, or ligand binding by PET/autoradiography was observed after IL-4 injection. Taken together, these results suggest that TSPO imaging specifically reveals the pro-inflammatory population of activated glial cells in the brain in response to inflammatory stimuli. Since the inflammatory phenotype of glial cells is critical to their role in neurological disease, these findings may enhance the utility and application of TSPO imaging.

18F-Trifluoromethanesulfinate Enables Direct C-H 18F-Trifluoromethylation of Native Aromatic Residues in Peptides

18F labeling strategies for unmodified peptides with [18F]fluoride require 18F-labeled prosthetics for bioconjugation more often with cysteine thiols or lysine amines. Here we explore selective radical chemistry to target aromatic residues applying C-H 18F-trifluoromethylation. We report a one-step route to [18F]CF3SO2NH4 from [18F]fluoride and its application to direct [18F]CF3 incorporation at tryptophan or tyrosine residues using unmodified peptides as complex as recombinant human insulin. The fully automated radiosynthesis of octreotide[Trp(2-CF218F)] enables in vivo positron emission tomography imaging.

PET Imaging of PARP Expression Using 18F-Olaparib

Poly(ADP-ribose) polymerase (PARP) inhibitors are increasingly being studied as cancer drugs, as single agents, or as a part of combination therapies. Imaging of PARP using a radiolabeled inhibitor has been proposed for patient selection, outcome prediction, dose optimization, genotoxic therapy evaluation, and target engagement imaging of novel PARP-targeting agents. Methods: Here, via the copper-mediated 18F-radiofluorination of aryl boronic esters, we accessed, for the first time (to our knowledge), the 18F-radiolabeled isotopolog of the Food and Drug Administration-approved PARP inhibitor olaparib. The use of the 18F-labeled equivalent of olaparib allows direct prediction of the distribution of olaparib, given its exact structural likeness to the native, nonradiolabeled drug. Results:18F-olaparib was taken up selectively in vitro in PARP-1-expressing cells. Irradiation increased PARP-1 expression and 18F-olaparib uptake in a radiation-dose-dependent fashion. PET imaging in mice showed specific uptake of 18F-olaparib in tumors expressing PARP-1 (3.2% ± 0.36% of the injected dose per gram of tissue in PSN-1 xenografts), correlating linearly with PARP-1 expression. Two hours after irradiation of the tumor (10 Gy), uptake of 18F-olaparib increased by 70% (P = 0.025). Conclusion: Taken together, we show that 18F-olaparib has great potential for noninvasive tumor imaging and monitoring of radiation damage.

Synthesis of 18F-difluoromethylarenes using aryl boronic acids, ethyl bromofluoroacetate and [18F]fluoride

Herein, we report the radiosynthesis of 18F-difluoromethylarenes via the assembly of three components, a boron reagent, ethyl bromofluoroacetate, and cyclotron-produced non-carrier added [18F]fluoride. The two key steps are a copper-catalysed cross-coupling reaction, and a Mn-mediated 18F-fluorodecarboxylation.

Synthesis and Reactivity of α-Cumyl Bromodifluoromethanesulfenate: Application to the Radiosynthesis of [18 F]ArylSCF3

A highly reactive electrophilic bromodifluoromethylthiolating reagent, α-cumyl bromodifluoro-methanesulfenate 1, was prepared to allow for direct bromodifluoromethylthiolation of aryl boron reagents. This coupling reaction takes place under copper catalysis, and affords a large range of bromodifluoromethylthiolated arenes. These compounds are amenable to various transformations including halogen exchange with [18 F]KF/K222  , a process giving access to [18 F]arylSCF3 in two steps from the corresponding aryl boronic pinacol esters.

18F-Trifluoromethylation of Unmodified Peptides with 5-18F-(Trifluoromethyl)dibenzothiophenium Trifluoromethanesulfonate

The 18F-labeling of 5-(trifluoromethyl)-dibenzothiophenium trifluoromethanesulfonate, commonly referred to as the Umemoto reagent, has been accomplished applying a halogen exchange 18F-fluorination with 18F-fluoride, followed by oxidative cyclization with Oxone and trifluoromethanesulfonic anhydride. This new 18F-reagent allows for the direct chemoselective 18F-labeling of unmodified peptides at the thiol cysteine residue.

Boron reagents for divergent radiochemistry

This review discusses boron reagents as precursors for divergent radiolabelling with a focus on carbon-11, fluorine-18 and iodine-123, -125, -131.

Rethinking digital preservation: definitions, models, and requirements

Purpose

This paper aims to clarify a mechanism for determining the robustness of digital preservation options given that the field has matured and contains a number of alternatives.

Design/methodology/approach

By examining the component activities of digital preservation, the open archival information system (OAIS) reference model and the trustworthy repository certification process, this paper outlines a possible new model for evaluating the caliber of any particular digital preservation mechanism.

Findings

This paper offers a more ordered and prescriptive model for evaluating digital preservation efforts.

Research limitations/implications

As a review of the OAIS reference model is underway, this paper seeks to contribute to that ongoing discussion to address several issues lacking in the current model and its effect on the certification process.

Originality/value

This paper identifies weaknesses in current practices and offers a model for addressing them.

Radiosynthesis of SPECT tracers via a copper mediated 123I iodination of (hetero)aryl boron reagents

A general method for the copper mediated nucleophilic 123I-iodination of (hetero)aryl boronic esters and acids has been developed. The broad substrate scope of this radiosynthetic approach allows access to [123I]DPA-713, [123I]IMPY, [123I]MIBG and [123I]IPEB that are four commonly used SPECT radiotracers. Our results infer that aryl boronic reagents can now be employed as common precursors for both fluorine-18 and iodine-123 radiolabelling.

Ecological speciation in sympatric palms: 2. Pre- and post-zygotic isolation

We evaluated reproductive isolation in two species of palms (Howea) that have evolved sympatrically on Lord Howe Island (LHI, Australia). We estimated the strength of some pre- and post-zygotic mechanisms in maintaining current species boundaries. We found that flowering time displacement between species is consistent across in and ex situ common gardens and is thus partly genetically determined. On LHI, pre-zygotic isolation due solely to flowering displacement was 97% for Howea belmoreana and 80% for H. forsteriana; this asymmetry results from H. forsteriana flowering earlier than H. belmoreana and being protandrous. As expected, only a few hybrids (here confirmed by genotyping) at both juvenile and adult stages could be detected in two sites on LHI, in which the two species grow intermingled (the Far Flats) or adjacently (Transit Hill). Yet, the distribution of hybrids was different between sites. At Transit Hill, we found no hybrid adult trees, but 13.5% of younger palms examined there were of late hybrid classes. In contrast, we found four hybrid adult trees, mostly of late hybrid classes, and only one juvenile F1 hybrid in the Far Flats. This pattern indicates that selection acts against hybrids between the juvenile and adult stages. An in situ reciprocal seed transplant between volcanic and calcareous soils also shows that early fitness components (up to 36 months) were affected by species and soil. These results are indicative of divergent selection in reproductive isolation, although it does not solely explain the current distribution of the two species on LHI.

Urbanism and Racial Attitudes

National survey data are used to test the relationship between urbanism and racial attitudes among whites, and a liberalizing effect of urbanism is found. The relationship is independent of differences in population composition occurring across the rural-urban continuum, and it operates largely in the same way in both the North and the South. Of the urban theories considered, the relationship is best explained by that portion of subcultural theory dealing with diffusion. Specifically, it appears that urbanism liberalizes racial attitudes by increasing equal-status, cooperative, and relatively personal contact between members of racial subcultures.

Effects of a Decade of Satellite Television in the Canadian Arctic

This article focuses on the longitudinal effects of Canadian network television relayed via satellite into the predominantly Eskimo community of Frobisher Bay. Comparisons are made among Euro-Canadian and Eskimo adolescents residing in Frobisher Bay, and Eskimo adolescents from isolated, more traditional settlements scattered throughout the region. Data collected in 1974 on a range of information levels and social-psychological postures are compared with those generated by two comparable survey instruments administered in 1980 and 1983. The data analysis revealed that many of the striking novelty effects on "television-town" Eskimo adolescents observed during 1974 were largely dissipated by 1980, a condition that remained essentially stable throughout 1983. The results are discussed within the context of the recently created Inuit Broadcasting Corporation and its potential counterweight role in tempering the negative psychological effects associated with modernization through culturally relevant television programming.

Enhanced copper-mediated (18)F-fluorination of aryl boronic esters provides eight radiotracers for PET applications

[(18)F]FMTEB, [(18)F]FPEB, [(18)F]flumazenil, [(18)F]DAA1106, [(18)F]MFBG, [(18)F]FDOPA, [(18)F]FMT and [(18)F]FDA are prepared from the corresponding arylboronic esters and [(18)F]KF/K222 in the presence of Cu(OTf)2py4. The method was successfully applied using three radiosynthetic platforms, and up to 26 GBq of non-carrier added starting activity of (18)F-fluoride.

The Use of Cryopreserved Human Skin Allograft for the Treatment of Wounds With Exposed Muscle, Tendon, and Bone

BACKGROUND

Wounds with exposed bone or tendon continue to be a challenge for wound care physicians, and there is little research pertaining to the treatment of these particular wounds with allograft skin. The purpose of this study was to evaluate the effectiveness and safety of a biologically active cryopreserved human skin allograft for treating wounds with exposed bone and/or tendon in the lower extremities.

METHODS

Fifteen patients with 15 wounds at a single hospital-based wound care center were included in the study. Eleven wounds had exposed bone, 1 wound had exposed ten- don, and 3 wounds had exposed bone and tendon. Standard treatment principles with adjunctive cadaveric allograft application were performed on all wounds in the study.

RESULTS

In this study 14/15 (93.3%) of the wounds healed completely. The mean duration of days until coverage of the bone and/or tendon with granulation tissue was 36.14 (5.16 weeks) (range 5-117 days). Mean duration to complete healing of the wound was 133 days (19 weeks) (range 53-311 days). The mean number of grafts applied was 2. There were no adverse events directly related to the graft. Zero major amputations and 1 minor amputation occurred.

CONCLUSION

This study found biologically active cryopreserved human skin allografts to be safe and effective in treating difficult wounds with exposed bone and/or tendon. To the authors' knowledge, this is the largest study to date focused on the utilization of allograft skin as an adjunct therapy for lower extremity wounds with exposed tendon and/or bone.

The Synthesis of Structurally Diverse Macrocycles By Successive Ring Expansion

Structurally diverse macrocycles and medium-sized rings (9-24 membered scaffolds, 22 examples) can be generated through a telescoped acylation/ring-expansion sequence, leading to the insertion of linear fragments into cyclic β-ketoesters without performing a discrete macrocyclization step. The key β-ketoester motif is regenerated in the ring-expanded product, meaning that the same sequence of steps can then be repeated (in theory indefinitely) with other linear fragments, allowing macrocycles with precise substitution patterns to be "grown" from smaller rings using the successive ring-expansion (SuRE) method.

Basal cell adenocarcinoma and Basal cell adenoma of the salivary glands: a clinicopathological review of seventy tumors with comparison of morphologic features and growth control indices

Basal cell adenoma and basal cell adenocarcinoma represent uncommon basaloid salivary gland neoplasms that show marked morphologic similarity. We wished to compare clinical outcome and morphologic features as well as growth and proliferation associated markers for both neoplasms. We reviewed the pathologic features of 70 neoplasms diagnosed as basal cell adenoma or basal cell adenocarcinoma. Observations included maximum mitotic activity and presence or absence of invasion into surrounding normal tissues as well as immunohistochemical studies for Ki-67, caspase 3, p53, and bcl-2. Establishing malignancy on the basis of invasion into surrounding benign tissues, 41 basal cell adenomas and 29 basal cell adenocarcinomas were identified. For tumors with follow-up, recurrence rates were 6.7 % for basal cell adenoma and 16.7 % for basal cell adenocarcinoma. One patient with basal cell adenocarcinoma had distant metastases and died of disease. Overall basal cell adenocarcinomas showed significantly higher values for growth and proliferation markers compared to basal cell adenomas. Salivary gland basal cell adenoma and basal cell adenocarcinoma show morphologic similarity. Basal cell adenocarcinoma can exhibit a locally aggressive behavior and has potential metastatic behavior. The overall mitotic rate and Ki-67 expression were higher in basal cell adenocarcinoma compared to basal cell adenoma, but overlap between the results of these observations in each tumor did not allow for accurate diagnosis or prediction of outcome in individual cases. We conclude that morphologic observation of local tissue invasion is the best marker for separating basal cell adenoma from basal cell adenocarcinoma.

Analysis of vitamin D status at two academic medical centers and a national reference laboratory: result patterns vary by age, gender, season, and patient location

BACKGROUND

Testing for 25-hydroxyvitamin D [25(OH)D] has increased dramatically in recent years. The present report compares overall utilization and results for 25(OH)D orders at two academic medical centers - one in New York and one in Iowa - in order to characterize the vitamin D status of our inpatient and outpatient populations. Results are also compared to those from a national reference laboratory to determine whether patterns at these two institutions reflect those observed nationally.

METHODS

Retrospective data queries of 25(OH)D orders and results were conducted using the laboratory information systems at Weill Cornell Medical College / New York Presbyterian Hospital (WCMC), University of Iowa Hospitals and Clinics (UIHC), and ARUP Laboratories (ARUP). Chart review was conducted for cases with very high or low serum 25(OH)D levels in the WCMC and UIHC datasets.

RESULTS

The majority of tests were ordered on females and outpatients. Average serum 25(OH)D levels were higher in female versus male patients across most ages in the WCMC, UIHC, and ARUP datasets. As expected, average serum 25(OH)D levels were higher in outpatients than inpatients. Serum 25(OH)D levels showed seasonal periodicity, with average levels higher in summer than winter and correlating to regional UV index. Area plots demonstrated a peak of increased 25(OH)D insufficiency / deficiency in adolescent females, although overall worse 25(OH)D status was found in male versus female patients in the WCMC, UIHC, and ARUP datasets. Surprisingly, improved 25(OH)D status was observed in patients starting near age 50. Finally, chart review of WCMC and UIHC datasets revealed over-supplementation (especially of ≥ 50,000 IU weekly doses) in the rare cases of very high 25(OH)D levels. General nutritional deficiency and/or severe illness was found in most cases of severe 25(OH)D deficiency.

CONCLUSIONS

25(OH)D status of patients seen by healthcare providers varies according to age, gender, season, and patient location. Improved 25(OH)D status was observed later in life, a finding that may reflect the previously described increased use of vitamin D-containing supplements in such populations. Severe vitamin D deficiency is much more common than vitamin D toxicity.

A 50-year-old man with back pain and a sellar mass. Metastatic hepatocellular carcinoma

Hepatocellular carcinoma rarely metastasizes to the pituitary gland and this site is very rarely the initial site of disease presentation. When it does, it may mimic a far more common pituitary adenoma. Metastatic hepatocellular carcinoma should be suspected in any individual with known liver disease or significant risk factors. The most common clinical sign of metastatic HCC to the skull is a subcutaneous mass followed by neurological deficits including visual disturbances, headache and seizure. The diagnosis can be made based on the histopathologic and immunohistochemical findings. When metastatic HCC is present in the skull base, appropriate work up should be done to rule out other metastatic sites, most commonly present in the spine.

Bullosis diabeticorum: is there a correlation between hyperglycemia and this symptomatology?

Bullosis diabeticorum (bullous disease of diabetes or diabetic bullae) is a noninflammatory, blistering disease occurring spontaneously in diabetic patients.The bullae are usually located on acral skin surfaces, particularly the feet. While this disease is unique to patients with diabetes, it may mimic other blistering disorders. This article reviews a case of a 75-year-old Hispanic male with type II diabetes mellitus who suffered from chronic diabetic bullae during an 11-year span. Researchers recorded the patient's blood glucose level on 50 occasions of bullae occurrence and 50 occasions when bullae were not present. It was discovered that the patient was more likely to experience bullae formation when his blood glucose level was elevated (t test analysis, P < 0.007). The etiology of bullosis diabeticorum may be multifactorial, but this study suggests poor regulation of blood glucose levels, particularly hyperglycemia, may have a significant impact on the manifestation of this dermopathy. .

Recent trauma is associated with antiretroviral failure and HIV transmission risk behavior among HIV-positive women and female-identified transgenders

Trauma and posttraumatic stress disorder disproportionally affect HIV-positive women. Studies increasingly demonstrate that both conditions may predict poor HIV-related health outcomes and transmission-risk behaviors. This study analyzed data from a prevention-with-positives program to understand if socio-economic, behavioral, and health-related factors are associated with antiretroviral failure and HIV transmission-risk behaviors among 113 HIV-positive biological and transgender women. An affirmative answer to a simple screening question for recent trauma was significantly associated with both outcomes. Compared to participants without recent trauma, participants reporting recent trauma had over four-times the odds of antiretroviral failure (AOR 4.3; 95% CI 1.1-16.6; p = 0.04), and over three-times the odds of reporting sex with an HIV-negative or unknown serostatus partner (AOR 3.9; 95% CI 1.3-11.9; p = 0.02) and <100% condom use with these partners (AOR 4.5; 95% CI 1.5-13.3; p = 0.007). Screening for recent trauma in HIV-positive biological and transgender women identifies patients at high risk for poor health outcomes and HIV transmission-risk behavior.

The symptomatic os vesalianum as an uncommon cause of lateral foot pain: a case report

The os vesalianum is an uncommon pedal accessory bone located lateral to the fifth metatarsal base. It may occasionally become symptomatic and require surgical excision, as in the case reported here in a 24-year-old woman. Simple excision of the ossicle, while effective in the present case, can be complicated by the attachment of fibers of the peroneus brevis tendon into the ossicle, thus requiring careful tenorraphy and sometimes tenodesis.

Keeping it simple: the Alabama Digital Preservation Network (ADPNet)

Purpose

The purpose of this paper is to present a brief overview of the current state of distributed digital preservation (DDP) networks in North America and to provide a detailed technical, administrative, and financial description of a working, self‐supporting DDP network: the Alabama Digital Preservation Network (ADPNet).

Design/methodology/approach

The paper reviews current regional and national initiatives in the field of digital preservation using a variety of sources and considers ADPNet in the context of generally accepted requirements for a robust DDP network. The authors view ADPNet in a comparative perspective with other Private LOCKSS Networks (PLNs) and argue that the Alabama model represents a promising approach to DDP for other states and consortia.

Findings

The paper finds that cultural memory organizations in a number of countries have identified digital preservation as a critical issue and are crafting strategies to address it, with DDP‐based solutions gaining in popularity in North America. It also identifies an array of technical, administrative, and financial challenges that DDP networks must resolve in order to be viable in the long term.

Practical implications

The paper describes a working model for building a low‐cost but robust DDP network.

Originality/value

The paper is one of the first comprehensive descriptions of a working, self‐sustaining DDP network.

Fracture stabilization of proximal tibial fractures with the proximal tibial LISS: early experience in Birmingham, Alabama (USA)

This study is a prospective evaluation of the Less Invasive Stabilization System (LTSS) for the treatment of high-energy tibial plateau and proximal tibial fractures treated between November, 1998 and June, 2000. Thirty-two patients sustained thirty-five acute fractures of the tibial plateau (25) or proximal tibia (10). These patients were injured primarily in blunt trauma accidents, with eighteen having multiple fractures, fifteen having ipsilateral extremity fractures, and eleven having major knee ligament injuries. Seventeen patients had open fractures. Thirty-four patients healed their fractures, with one developing a nonunion. Two patients developed infections, both following Type III open fractures. Final range of motion averaged 2 to 116 degrees. Alignment was well maintained, with no patient losing the alignment that was obtained in the operating room. The tibial LISS system worked well at stabilizing difficult fractures of the tibial plateau and proximal tibia with a low incidence of complications in this preliminary study with short-term follow-up.

Are you paying too much for that acquisition?

Despite 30 years of evidence demonstrating that most acquisitions don't create value for the acquiring company, executives continue to make more deals, and bigger deals, every year. There are plenty of reasons why value isn't created, but many times it's simply because the acquiring company paid too much. It's not, however, that acquirers pay too high a price in an absolute sense. Rather, they pay more than the acquisition is worth to them. What is that optimum price? The authors present a systematic way to arrive at it, involving several distinct concepts of value. In today's market, the purchase price of an acquisition will nearly always be higher than the intrinsic value of the company--the price of its stock before any acquisition intentions are announced. The key is to determine how much of that difference is "synergy value"--the value that will result from improvements made when the companies are combined. This value will accrue to the acquirer's shareholders rather than to the target's shareholders. The more synergy value a particular acquisition can generate, the higher the maximum price an acquirer is justified in paying. Just as important as correctly calculating the synergy value is having the discipline to walk away from a deal when the numbers don't add up. If returns to shareholders from acquisitions are no better in the next ten years than they've been in the past 30, the authors warn, it will be because companies have failed to create systematic corporate governance processes that put their simple lessons into practice.

Comparison of synthetic saponin cholesterol absorption inhibitors in rabbits: evidence for a non-stoichiometric, intestinal mechanism of action

The hypocholesterolemic activities of pamaqueside and tiqueside, two structurally similar saponins, were evaluated in cholesterol-fed rabbits. The pharmacological profiles of the saponins were virtually identical: both dose-dependently decreased the intestinal absorption of labeled cholesterol 25-75%, increased fecal neutral sterol excretion up to 2.5-fold, and decreased hepatic cholesterol content 10-55%. High doses of pamaqueside (>5 mg/kg) or tiqueside (>125 mg/kg) completely prevented hypercholesterolemia. Decreases in plasma and hepatic cholesterol levels were strongly correlated with increased neutral sterol excretion. Ratios of neutral sterol excreted to pamaqueside administered were greater than 1:1 at all doses, in opposition to the formation of a stoichiometric complex previously suggested for tiqueside and other saponins. Ratios in tiqueside-treated rabbits were less than unity, a reflection of its lower potency. Pamaqueside-treated rabbits exhibited a more rapid decline in plasma cholesterol concentrations than control animals fed a cholesterol-free diet, indicating that the compound also inhibited the absorption of biliary cholesterol. Intravenous administration of pamaqueside had no effect on plasma cholesterol levels despite plasma levels twice those observed in rabbits given pamaqueside orally. These data indicate that pamaqueside and tiqueside induce hypocholesterolemia by blocking lumenal cholesterol absorption via a mechanism that apparently differs from the stoichiometric complexation of cholesterol hypothesized for other saponins.

Kinetics of drug action in disease states. XLIII: Potentiating effect of L-tryptophan on the hypnotic action of phenobarbital and ethanol in rats

The essential amino acid L-tryptophan has been widely used as a sleeping aid because it can produce drowsiness and decrease sleep latency. Its concentrations in plasma and brain and its binding to plasma protein are markedly altered in hepatic encephalopathy and renal failure. The purpose of this investigation was to determine if L-tryptophan can enhance the sensitivity of the central nervous system to the hypnotic actions of a barbiturate and an alcohol. Female rats weighing approximately 200 g received an intravenous infusion of L-tryptophan (0.8 or 0.08 mg/min) for 30 min and then an infusion of phenobarbital (0.824 mg/min) with L-tryptophan (0.8 or 0.08 mg min-1) until the onset of loss of righting reflex (LRR). Control animals received an infusion of saline solution for 30 min and then phenobarbital without the amino acid. Similar experiments were performed with ethanol (16.3 mg/min), with and without L-tryptophan (0.8 mg/min). L-Tryptophan infused alone at a rate of 3.8 mg/min for 84 min did not cause LRR. Administration of L-tryptophan at a rate of 0.8 mg/min with phenobarbital was associated with statistically significant reductions in the total dose and concentrations of phenobarbital in serum, serum water, brain, and cerebrospinal fluid (CSF) at onset of LRR. The 0.08 mg/min infusion of L-tryptophan had a less pronounced effect, with statistically significant reductions of phenobarbital concentrations at onset of LRR in brain and CSF. L-Tryptophan also significantly reduced the total dose and the concentrations of ethanol in serum, brain, and CSF required to produce LRR.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitation of the novel anticonvulsant remacemide in rat and dog plasma and urine: application of the plasma methodology to measure the plasma protein binding of remacemide

Sensitive and selective methods have been developed for quantitation of the novel anticonvulsant remacemide in rat and dog plasma and urine. The methods employed liquid-liquid extraction (urine) or ion-exchange solid-phase extraction (plasma), with an internal standard, followed by high-performance liquid chromatography with ultraviolet detection. The detection limit for both methods was 10 ng/ml. Overall accuracy was 0.00% for plasma and -1.4% for urine with a precision of 6.04 and 3.87% for plasma and urine, respectively. The standard curves were linear for both plasma and urine over a wide concentration range (9.96-2490 ng/ml). The plasma method was also applied to measurement of in vitro plasma protein binding of remacemide in rat, dog and human plasma.