Discovery of Sulanemadlin (ALRN-6924), the First Cell-Permeating, Stabilized α-Helical Peptide in Clinical Development

We report the discovery of sulanemadlin (ALRN-6924), the first cell-permeating, stabilized α-helical peptide to enter clinical trials. ALRN-6924 is a "stapled peptide" that mimics the N-terminal domain of the p53 tumor suppressor protein. It binds with high affinity to both MDM2 and MDMX (also known as MDM4), the endogenous inhibitors of p53, to activate p53 signaling in cells having a non-mutant, or wild-type TP53 genotype (TP53-WT). Iterative structure-activity optimization endowed ALRN-6924 with favorable cell permeability, solubility, and pharmacokinetic and safety profiles. Intracellular proteolysis of ALRN-6924 forms a long-acting active metabolite with potent MDM2 and MDMX binding affinity and slow dissociation kinetics. At high doses, ALRN-6924 exhibits on-mechanism anticancer activity in TP53-WT tumor models. At lower doses, ALRN-6924 transiently arrests the cell cycle in healthy tissues to protect them from chemotherapy without protecting the TP53-mutant cancer cells. These results support the continued clinical evaluation of ALRN-6924 as an anticancer and chemoprotection agent.

Correcting for missing and irregular data in home-range estimation

Home-range estimation is an important application of animal tracking data that is frequently complicated by autocorrelation, sampling irregularity, and small effective sample sizes. We introduce a novel, optimal weighting method that accounts for temporal sampling bias in autocorrelated tracking data. This method corrects for irregular and missing data, such that oversampled times are downweighted and undersampled times are upweighted to minimize error in the home-range estimate. We also introduce computationally efficient algorithms that make this method feasible with large data sets. Generally speaking, there are three situations where weight optimization improves the accuracy of home-range estimates: with marine data, where the sampling schedule is highly irregular, with duty cycled data, where the sampling schedule changes during the observation period, and when a small number of home-range crossings are observed, making the beginning and end times more independent and informative than the intermediate times. Using both simulated data and empirical examples including reef manta ray, Mongolian gazelle, and African buffalo, optimal weighting is shown to reduce the error and increase the spatial resolution of home-range estimates. With a conveniently packaged and computationally efficient software implementation, this method broadens the array of data sets with which accurate space-use assessments can be made.

Estimating where and how animals travel: an optimal framework for path reconstruction from autocorrelated tracking data

An animal's trajectory is a fundamental object of interest in movement ecology, as it directly informs a range of topics from resource selection to energy expenditure and behavioral states. Optimally inferring the mostly unobserved movement path and its dynamics from a limited sample of telemetry observations is a key unsolved problem, however. The field of geostatistics has focused significant attention on a mathematically analogous problem that has a statistically optimal solution coined after its inventor, Krige. Kriging revolutionized geostatistics and is now the gold standard for interpolating between a limited number of autocorrelated spatial point observations. Here we translate Kriging for use with animal movement data. Our Kriging formalism encompasses previous methods to estimate animal's trajectories--the Brownian bridge and continuous-time correlated random walk library--as special cases, informs users as to when these previous methods are appropriate, and provides a more general method when they are not. We demonstrate the capabilities of Kriging on a case study with Mongolian gazelles where, compared to the Brownian bridge, Kriging with a more optimal model was 10% more precise in interpolating locations and 500% more precise in estimating occurrence areas.

Rigorous home range estimation with movement data: a new autocorrelated kernel density estimator

Quantifying animals' home ranges is a key problem in ecology and has important conservation and wildlife management applications. Kernel density estimation (KDE) is a workhorse technique for range delineation problems that is both statistically efficient and nonparametric. KDE assumes that the data are independent and identically distributed (IID). However, animal tracking data, which are routinely used as inputs to KDEs, are inherently autocorrelated and violate this key assumption. As we demonstrate, using realistically autocorrelated data in conventional KDEs results in grossly underestimated home ranges. We further show that the performance of conventional KDEs actually degrades as data quality improves, because autocorrelation strength increases as movement paths become more finely resolved. To remedy these flaws with the traditional KDE method, we derive an autocorrelated KDE (AKDE) from first principles to use autocorrelated data, making it perfectly suited for movement data sets. We illustrate the vastly improved performance of AKDE using analytical arguments, relocation data from Mongolian gazelles, and simulations based upon the gazelle's observed movement process. By yielding better minimum area estimates for threatened wildlife populations, we believe that future widespread use of AKDE will have significant impact on ecology and conservation biology.

Abstract LB-304: ATSP-9172, a novel Stapled Peptide inhibitor of HIF-dependent transcriptional activity with in vivo antitumor efficacy in a preclinical model of prostate cancer

Hypoxia-inducible transcription factors (HIF) are key regulators of cellular adaptation to hypoxia in solid tumors, and HIF-1α controls the expression of genes involved in anaerobic metabolism, angiogenesis, cell growth and survival. Hydrocarbon cross-linked alpha helical peptides (Stapled Peptides) are a breakthrough approach to create new class of drugs that modulate intracellular protein-protein interactions. Here, we have mimicked the structure and function of the CITED2 protein, an endogenous negative regulator of the interaction between HIF-1α and p300 proteins, by designing a Stapled Peptide derived from CITED2 to generate the first example of a potent and selective Stapled Peptide inhibitor of HIF-1α-dependent transcription. ATSP-9172 bound to the CH1 domain of p300 and disrupted the HIF-1α C-TAD/CH1 interaction in biochemical assays and inhibited HIF-dependent reporter gene activity in ME-180 cells. Examination of endogenous transcript levels in ME-180 cells revealed that ATSP-9172 down-regulated the transcription of HIF-1α target genes, such as adolase C, angiopoietin-like 4, and carbonic anhydrase 9 in a dose-dependent manner, but did not affect the expression of non-HIF target genes, verifying a specific and on-target mechanism of action. ATSP-9172 exhibited a dramatic improvement in solubility and plasma stability profile relative to the linear peptide, and demonstrated favorable pharmacokinetic properties in mice by providing high systemic exposure, low plasma clearance and long elimination half-life. Finally, intravenous administration of ATSP-9172 on an every other day schedule significantly inhibited tumor growth in a PC-3 human prostate tumor xenograft model (p < 0.05); this inhibition was found to be dose-dependent. Our results demonstrate that a Stapled Peptide mimicking the HIF inhibitory function of the native CITED2 protein provides a novel and specific strategy to suppress HIF-1α-dependent gene expression for cancer therapy.

Citation Format: Kaiming Sun, Steven J. DeMarco, Vincent Guerlavais, Aditi Mukherjee, Sean Irwin, Eric Shi, Hongliang Cai, Krzysztof Darlak, Solimar Santiago, Jessica Pero, Karen A. Olson, Huw M. Nash, Yong Chang. ATSP-9172, a novel Stapled Peptide inhibitor of HIF-dependent transcriptional activity with in vivo antitumor efficacy in a preclinical model of prostate cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-304. doi:10.1158/1538-7445.AM2013-LB-304

Cinacalcet hydrochloride reduces the serum calcium concentration in inoperable parathyroid carcinoma

BACKGROUND

Management of inoperable parathyroid carcinoma presents a challenge because until recently, effective medical therapy was not available. Morbidity and mortality result primarily from severe hypercalcemia. We assessed the ability of the calcimimetic cinacalcet HCl to reduce serum calcium in patients with parathyroid carcinoma as well as its effect on PTH concentrations, bone turnover markers, safety, and health-related quality of life variables.

METHODS

Twenty-nine patients with parathyroid carcinoma were enrolled in this open-label, single-arm study consisting of titration and maintenance phases. Cinacalcet doses were titrated (30 mg twice daily to 90 mg four times daily) for 16 wk or until serum calcium was no more than 10.0 mg/dl. The study endpoint was the proportion of patients with at least a 1 mg/dl reduction in serum calcium at the end of the titration phase (responders).

RESULTS

Mean (+/- se) serum calcium (14.1 +/- 0.4 mg/dl) and PTH (697 +/- 94 pg/ml) were markedly elevated at baseline. At the end of the titration period, serum calcium was reduced by at least 1 mg/dl in 62% of patients (mean decline to 12.4 +/- 0.5 mg/dl). In the 18 responders, serum calcium fell from 15.0 +/- 0.5 to 11.2 +/- 0.3 mg/dl (P < 0.001). The greatest reductions in serum calcium were observed in patients with highest baseline calcium levels. PTH levels decreased, but not significantly, to 635 +/- 73 pg/ml (-4.6%). Adverse events included nausea, vomiting, headache, and fracture.

CONCLUSIONS

Cinacalcet effectively reduces hypercalcemia in approximately two thirds of patients with inoperable parathyroid carcinoma and may represent an important new treatment option for these patients.

Cinacalcet HCl (Sensipar/ Mimpara) is an effective chronic therapy for hemodialysis patients with secondary hyperparathyroidism

AIMS

This 1-year double-blind, placebo-controlled, multicenter study evaluated the long-term safety and efficacy of cinacalcet for the treatment of secondary hyperparathyroidism in patients receiving hemodialysis.

METHOD

Patients were randomly assigned in a 1:1 ratio to cinacalcet or control treatment groups. The initial dose of cinacalcet (or matching placebo) was 30 mg. Doses were titrated every 3 or 4 weeks based on the intact parathyroid hormone (iPTH) response and safety profile. Sequential doses included 30, 60, 90, 120 and 180 mg/d. Phosphate binders and vitamin D sterols were adjusted per protocol as needed to control levels of calcium and phosphorus. Efficacy and safety were compared between treatment groups among patients who completed the study (52 total weeks of treatment). Reasons for withdrawal are presented for patients who did not complete the study.

RESULTS

A total of 210 patients completed 52 weeks of double-blinded treatment with cinacalcet (n = 99) or placebo (n = 111). Over the last 6 months of the study, a greater proportion of patients in the cinacalcet group than the control group achieved an iPTH level < or = 250 pg/ml (61.6 vs. 9.9%, p < 0.001) or a > or = 30% decrease in iPTH from baseline (81.8 vs. 21.6%, p < 0.001). Mean iPTH levels decreased by -47.8% in the cinacalcet group and increased by +12.9% in the control group. Mean percentage changes in other laboratory values in the cinacalcet and control groups included the following: serum calcium -6.5 vs. +0.9% (p < 0.001), serum phosphorus -3.6 vs. -1.1% (p = 0.465), and Ca x P -9.9 vs. -0.3% (p = 0.006). The most commonly reported adverse events related to study drug by the investigators included nausea (13% cinacalcet, 5% control), investigator-reported hypocalcemia (11% cinacalcet, 1% control), vomiting (9% cinacalcet, 2% control), dyspepsia (5% cinacalcet, 4% control), and diarrhea (5% cinacalcet, 2% control).

CONCLUSIONS

Treatment with cinacalcet is a safe and effective therapy for long-term control of secondary hyperparathyroidism. 1-year therapy with cinacalcet was associated with sustained, clinically significant reductions in calcium, Ca x P and iPTH which allowed a greater percentage of patients to achieve NKF-KDOQI target goals for PTH and Ca x P.

Neamine inhibits xenografic human tumor growth and angiogenesis in athymic mice

PURPOSE

We have previously shown that the aminoglycoside antibiotic neomycin blocks the nuclear translocation of angiogenin and inhibits its angiogenic activity. However, neomycin has not been considered as a favorable drug candidate for clinical development because of its known nephrotoxicity and ototoxicity. The aim of this study is to determine whether neamine, a nontoxic derivative of neomycin, possesses antitumor activity.

EXPERIMENTAL DESIGN

The effect of neamine on the nuclear translocation of angiogenin was examined by means of immunofluorescence and Western blotting. The antitumor activity of neamine was determined with three different animal models.

RESULTS

Neamine effectively blocked the nuclear translocation of angiogenin in endothelial cells and inhibited angiogenin-induced cell proliferation. It inhibited the establishment of human tumor xenografts in athymic mice in both ectopic and orthotopic tumor models. It also inhibited the progression of established human tumor transplants, whereas the structurally related antibiotic paromomycin had no effect. Immunohistochemical staining showed that both angiogenesis and cancer cell proliferation are inhibited by neamine.

CONCLUSION

These results suggest that the nontoxic aminoglycoside antibiotic neamine is an effective inhibitor of nuclear translocation of angiogenin and may serve as an inhibitor for angiogenin-induced angiogenesis and cancer progression.

Angiogenin is translocated to the nucleus of HeLa cells and is involved in ribosomal RNA transcription and cell proliferation

Angiogenin is an angiogenic protein known to play a role in rRNA transcription in endothelial cells. Nuclear translocation of angiogenin in endothelial cells decreases as cell density increases and ceases when cells are confluent. Here we report that angiogenin is constantly translocated to the nucleus of HeLa cells in a cell density-independent manner. Down-regulation of angiogenin expression by antisense and RNA interference results in a decrease in rRNA transcription, ribosome biogenesis, proliferation, and tumorigenesis both in vitro and in vivo. Exogenous angiogenin rescues the cells from antisense and RNA interference inhibition. The results showed that angiogenin is constitutively translocated into the nucleus of HeLa cells where it stimulates rRNA transcription. Thus, besides its angiogenic activity, angiogenin also plays a role in cancer cell proliferation.

Endogenous angiogenin in endothelial cells is a general requirement for cell proliferation and angiogenesis

Angiogenin is an angiogenic protein that undergoes nuclear translocation in endothelial cells where it accumulates in the nucleolus and stimulates rRNA transcription, a rate-limiting step in ribosome biogenesis, protein translation, and cell growth. Here, we report that angiogenin is required for cell proliferation induced by various other angiogenic proteins including acidic and basic fibroblast growth factors (aFGF and bFGF), epidermal growth factor (EGF), and vascular endothelial growth factor (VEGF). Downregulation of angiogenin in endothelial cells by small interfering RNA (siRNA) and antisense results in a decrease in rRNA transcription, ribosome biogenesis, and cell proliferation induced by these angiogenic factors. Inhibitors of the nuclear translocation of angiogenin abolish the angiogenic activities of these factors. Stable angiogenin antisense transfection in HeLa cells reduces tumor angiogenesis in athymic mice despite the elevated expression level of bFGF and VEGF. Thus, nuclear angiogenin assumes an essential role in endothelial cell proliferation and is necessary for angiogenesis induced by other angiogenic factors. Angiogenin-stimulated rRNA transcription in endothelial cells may thus serve as a crossroad in the process of angiogenesis induced by various angiogenic factors.

The crystal structure of human angiogenin in complex with an antitumor neutralizing antibody

The murine monoclonal antibody 26-2F neutralizes the angiogenic and ribonucleolytic activities of human angiogenin (ANG) and is highly effective in preventing the establishment and metastatic dissemination of human tumors in athymic mice. Here we report a 2.0 A resolution crystal structure for the complex of ANG with the Fab fragment of 26-2F that reveals the detailed interactions between ANG and the complementarity-determining regions (CDRs) of the antibody. Surprisingly, Fab binding induces a dramatic conformational change in the cell binding region of ANG at the opposite end of the molecule from the combining site; crosslinking experiments indicate that this rearrangement also occurs in solution. The ANG-Fab complex structure should be invaluable for designing maximally humanized versions of 26-2F for potential clinical use.

A small-molecule inhibitor of the ribonucleolytic activity of human angiogenin that possesses antitumor activity

The results of previous preclinical and clinical studies have identified angiogenin (ANG) as a potentially important target for anticancer therapy. Here we report the design and implementation of a high-throughput screening assay to identify small molecules that bind to the ribonucleolytic active site of ANG, which is critically involved in the induction of angiogenesis by this protein. Screening of 18,310 compounds from the National Cancer Institute (NCI) Diversity Set and ChemBridge DIVERSet yielded 15 hits that inhibit the enzymatic activity of ANG with K(i) values <100 microM. One of these, NCI compound 65828 [8-amino-5-(4'-hydroxybiphenyl-4-ylazo)naphthalene-2-sulfonate; K(i) = 81 microM], was selected for more detailed studies. Minor changes in ANG or ligand structure markedly reduced potency, demonstrating that inhibition reflects active-site rather than nonspecific binding; these observations are consistent with a computationally generated model of the ANG.65828 complex. Local treatment with modest doses of 65828 significantly delayed the formation of s.c. tumors from two distinct human cancer cell types in athymic mice. ANG is the likely target involved because (i) a 65828 analogue with much lower potency against the enzymatic activity of ANG failed to exert any antitumor effect, (ii) tumors from 65828-treated mice had fewer interior blood vessels than those from control mice, and (iii) 65828 appears to have no direct effect on the tumor cells. Our findings provide considerable support for the targeting of the enzymatic active site of ANG as a strategy for developing new anticancer drugs.

Inhibition of prostate carcinoma establishment and metastatic growth in mice by an antiangiogenin monoclonal antibody

A neutralizing monoclonal antibody (MAb) 26-2F to human angiogenin, a potent inducer of neovascularization, has been shown previously to prevent or delay the appearance of angiogenin-secreting human colon, fibrosarcoma and lung tumor cell xenografts implanted subcutaneously (s.c.) into athymic mice. In an analogous model system, we report here that the antibody also prevents the establishment of PC-3 androgen-independent human prostate cancer tumors in, on average, 40% of treated mice (p < 0.0001, survivor analysis). Intriguingly, combining MAb 26-2F together with cisplatin and suramin, 2 therapeutic agents that together showed little antitumor activity in the aforementioned model, resulted in an even greater degree of protection (71% protected, p = 0.009 compared to antibody treatment alone). This protective effect persisted several weeks after cessation of treatment. Additionally, prophylactic systemic administration of MAb 26-2F dramatically reduced by 50% the formation of spontaneous regional metastasis originating from primary growth in the prostate gland of PC-3M cells, highly metastatic variants of PC-3. Protection from metastasis was still significant when treatment with MAb 26-2F was delayed until after the primary tumor was well established. The antibody is not directly cytotoxic to either cell type, both of which secrete angiogenin in vitro and when growing as tumors in vivo, but changes the pattern of vascularity in primary tumors growing orthotopically. These findings, together with the observation that angiogenin protein and mRNA are apparently overexpressed in cancerous vs. normal human prostate tissues, demonstrate that angiogenin antagonism represents a promising new approach for preventing progression and metastasis of clinical prostate cancer.

Prevention of human prostate tumor metastasis in athymic mice by antisense targeting of human angiogenin

PURPOSE

Angiogenin is a potent positive mediator of neovascularization, a process required for both primary tumor growth and metastasis. In the present study, the effect of a fully phosphorothioated antisense oligodeoxynucleotide, designated JF2S, targeting the AUG translation initiation codon region of human angiogenin, on human prostate tumor development and metastasis in athymic mice was examined.

EXPERIMENTAL DESIGN

JF2S was evaluated for its capacity to affect in vitro synthesis of angiogenin and subsequent tumorigenicity of transiently transfected prostate tumor cells in mice. In vivo treatment experiments were then conducted in which JF2S was used to prevent formation of tumors in an ectopic model and metastasis in an orthotopic model.

RESULTS

Transient transfection of tumor cells with JF2S inhibited both angiogenin gene expression in vitro and tumorigenicity of these transfected cells in athymic mice. In therapy experiments, local treatment with JF2S completely protected mice from developing prostate tumors after s.c. injection of PC-3 human prostate tumor cells (P < 0.0001, survivor analysis). Most importantly, systemic prophylactic administration of JF2S prevented, in 47% of mice, formation of regional iliac lymph node micrometastases arising from primary tumors growing in the more natural orthotopic prostate setting (P = 0.0003, Fisher's exact test). Furthermore, total protection from regional metastasis occurred in those mice in which JF2S treatment successfully diminished human angiogenin expression in vivo. Tumor-associated angiogenesis was also impaired by JF2S treatment. When therapy was delayed until all of the mice harbored primary tumors in the prostate, the incidence of regional metastasis was still significantly decreased (P < 0.005, survivor analysis).

CONCLUSIONS

These findings demonstrate that human prostate cancer establishment and spread in athymic mice is extremely susceptible to targeted disruption of tumor-derived human angiogenin gene expression. Therefore, angiogenin is a valid target against which to devise preventative strategies for prostate cancer metastasis.

Two regulators of Ste12p inhibit pheromone-responsive transcription by separate mechanisms

The yeast Saccharomyces cerevisiae transcription factor Ste12p is responsible for activating genes in response to MAP kinase cascades controlling mating and filamentous growth. Ste12p is negatively regulated by two inhibitor proteins, Dig1p (also called Rst1p) and Dig2p (also called Rst2p). The expression of a C-terminal Ste12p fragment (residues 216 to 688) [Ste12p(216-688)] from a GAL promoter causes FUS1 induction in a strain expressing wild-type STE12, suggesting that this region can cause the activation of endogenous Ste12p. Residues 262 to 594 are sufficient to cause STE12-dependent FUS1 induction when overexpressed, and this region of Ste12p was found to bind Dig1p but not Dig2p in yeast extracts. In contrast, recombinant glutathione S-transferase-Dig2p binds to the Ste12p DNA-binding domain (DBD). Expression of DIG2, but not DIG1, from a GAL promoter inhibits transcriptional activation by an Ste12p DBD-VP16 fusion. Furthermore, disruption of dig1, but not dig2, causes elevated transcriptional activation by a LexA-Ste12p(216-688) fusion. Ste12p has multiple regions within the C terminus (flanking residue 474) that can promote multimerization in vitro, and we demonstrate that these interactions can contribute to the activation of endogenous Ste12p by overproduced C-terminal fragments. These results demonstrate that Dig1p and Dig2p do not function by redundant mechanisms but rather inhibit pheromone-responsive transcription through interactions with separate regions of Ste12p.

Regulation of angiogenin expression in human HepG2 hepatoma cells by mediators of the acute-phase response

Angiogenin is a potent inducer of neovascularization in vivo. However, like other angiogenic molecules, its specific physiologic roles and mechanisms regulating its expression remain to be elucidated. Angiogenin is a liver-derived component of normal serum whose concentration can increase in various disease states. This suggests that it might participate in the acute-phase response. In an initial study we showed that angiogenin protein and mRNA levels transiently increased in mice following an acute inflammatory stimulus. We now report that IL-6, a major inducer of acute-phase proteins, stimulates the synthesis and secretion of angiogenin protein in human HepG2 cells within 24 hr following treatment, an effect enhanced by dexamethasone. IL-6 also increases the amount of angiogenin mRNA without altering its half-life. This increase, suppressible by cycloheximide, peaks at 12 hr following stimulation and returns to basal levels by 48 hr. IL-1 alone slightly decreases the basal production of angiogenin protein and mRNA, but essentially abolishes the response to IL-6 in the absence or presence of dexamethasone. This antagonistic effect by IL-1 on IL-6 activity is not a result of changes in mRNA stability nor is it dependent on new protein synthesis. Thus, the combined effects of IL-6, IL-1, glucocorticoids, and perhaps other related factors may specifically control angiogenin expression. Since angiogenin is regulated in a manner similar to that of acute phase proteins both in vitro and in vivo, it may play a role in the host response to injury.

Representations of knowledge about dominoes in demented and normal elderly players

1. Dementia patients who retain musical and game-playing skills exhibit impaired performance on explicit memory tests of knowledge about their retained skill. 2. Dementia patients who retain skill at playing dominoes can answer complex questions about the play of the game almost as well as normal elderly domino players when the questions are presented with real dominoes. 3. The aim of this study was to determine if skilled dementia patients could answer questions about domino play when the stimuli were two-dimensional drawings of dominoes. 4. Seventeen dementia patients and eight normal elderly domino players were tested on two forms of the Domino Quiz: first with real dominoes, then with two-dimensional drawings; other neuropsychological tests were given at the same time. 5. Fourteen of the 17 patients and all of the controls showed no decline in answering questions about domino play when two-dimensional drawings were used. These patients showed retained symbolic processing of information about dominoes despite declines in overall mental status, generation of words from specific semantic categories, and recognition memory for domino terminology. 6. Because the 14 patients with retained domino skill performed as accurately as controls on both administrations of a letter cancellation task, the ability to process familiar symbols may be important to their game-playing skill.

Correlates of coping style in patients with multiple sclerosis

To examine certain correlates of patterns of coping with stress, 43 patients with multiple sclerosis (MS) read a vignette describing a stressful social situation and completed the Ways of Coping Checklist, describing how they would cope with the stressful situation. Performance on a test of solving problems in everyday living was positively correlated with the total number of coping responses and with the number of problem-focused strategies, but neither vocabulary nor verbal abstract reasoning were related to coping patterns. In agreement with earlier work, increases in psychological distress were positively correlated with endorsement of emotion-focused coping strategies but unrelated to the use of other coping responses.

Chimeric anti-angiogenin antibody cAb 26-2F inhibits the formation of human breast cancer xenografts in athymic mice

Angiogenin (Ang), an inducer of neovascularization, is secreted by several types of human tumor cells and appears critical for their growth. The murine anti-Ang monoclonal antibody (mAb) 26-2F neutralizes the activities of Ang and dramatically prevents the establishment and metastatic dissemination of human tumor cell xenografts in athymic mice. However, for use clinically, the well-documented problem of the human anti-globulin antibody response known to occur with murine antibodies requires resolution. As a result, chimeric as well as totally humanized antibodies are currently being evaluated as therapeutic agents for the treatment of several pathological conditions, including malignancy. Therefore, we have constructed a chimeric mouse/human antibody based on the structure of mAb 26-2F. Complementary DNAs from the light and heavy chain variable regions of mAb 26-2F were cloned, sequenced, and genetically engineered by PCR for subcloning into expression vectors that contain human constant region sequences. Transfection of these vectors into nonproducing mouse myeloma cells resulted in the secretion of fully assembled tetrameric molecules. The chimeric antibody (cAb 26-2F) binds to Ang and inhibits its ribonucleolytic and angiogenic activities as potently as mAb 26-2F. Furthermore, the capacities of cAb 26-2F and its murine counterpart to suppress the formation of human breast cancer tumors in athymic mice are indistinguishable. Thus cAb 26-2F, with its retained neutralization capability and likely decreased immunogenicity, may be of use clinically for the treatment of human cancer and related disorders where pathological angiogenesis is a component.

Angiogenin is regulated in vivo as an acute phase protein

Angiogenin (Ang), a potent mediator of neovascularization, is secreted by and is critical for the growth of human tumor cells in experimental animals. However, control mechanisms that regulate its expression under normal physiological conditions have not been described. We have determined previously that Ang is present in normal human serum and that its concentration, normally falling within a narrow range, can vary widely in hospitalized patients. This observation, plus a report that Ang is synthesized in the adult liver, led us to investigate whether it can be regulated as an acute phase protein (APP). Ang concentration in the serum of mice placed into the acute phase by injection with 3% thioglycollate do indeed increase transiently as is typical for APPs. Moreover, a liver-specific rise and subsequent fall in Ang mRNA transcripts also follows entrance into acute inflammation. We conclude that Ang can be regulated in vivo in a manner that is characteristic of an APP and, therefore, may contribute to the angiogenic component of tissue repair that accompanies host response to inflammation and trauma. To our knowledge, this is the first demonstration that a well-characterized angiogenic mediator can be regulated as an APP.

Expression of game-related and generic knowledge by dementia patients who retain skill at playing dominoes

Patients with dementia who remain skilled at musical performance or playing bridge fail explicit memory tests for information related to their skills, suggesting that implicit memory mediates their preserved skills. To reexamine this issue, 23 dementia patients and 15 elderly controls of comparable domino-playing skill were compared on tests of naming, verbal fluency, and domino knowledge. On an explicit test of domino knowledge, the patients scored well below the elderly controls, performing no better than students who were unfamiliar with the game. But when game-like situations were created with real dominoes, both the skilled controls and the patients with dementia chose optimal moves and verbally explained their choices equally well. On naming and fluency tests, the skilled patients showed no advantage over patients of comparable dementia severity who had no retained skill. In dementia, some complex knowledge seems intact but is accessible only in particular contexts.

Characterization of the basal and pheromone-stimulated phosphorylation states of Ste12p

The Saccharomyces cerevisiae transcription factor Ste12p is required for basal and activated expression of pheromone-responsive genes, and for invasive growth in haploid cells. In diploid yeast, Ste12p is implicated in pseudohyphal development. The ability of Ste12p to effect these various responses in three different cell types must require stringent regulation of its transcriptional activation function and interaction with additional transcription factors. We have examined the phosphorylation state of Ste12p in untreated and pheromone-treated haploid cells, and found eight constitutively phosphorylated peptides. Phosphorylation at the constitutive sites does not require the protein kinases of the pheromone-response pathway. Treatment of haploid yeast with mating pheromone causes the appearance of novel relatively minor phosphorylations on Ste12p. Brief [35S]methionine labeling reveals novel pheromone-dependent, electrophoretically slower migrating Ste12p species. Similarly, the sole difference we observe in tryptic phosphopeptides generated from Ste12p from pheromone-treated and untreated cells is the transient appearance of two novel minor hydrophobic phosphopeptides. The pheromone-dependent phosphorylation of Ste12p requires an intact pheromone-response pathway and localization of Ste12p to the nucleus, but does not require the Ste12p DNA-binding domain. We conclude from these experiments that the pheromone-response pathway induces the formation of specific hyperphosphorylation on Ste12p, which can only be detected as apparently minor modifications in vivo. We argue that, if Ste12p is regulated by direct pheromone-responsive phosphorylation, then that phosphorylation must be represented by the two novel phosphopeptides. However, we cannot exclude the possibility that pheromone-responsive transcription is controlled by direct phosphorylation of a target other than Ste12p.

Fall-related occupational injuries on farms

We assessed risk factors for fall-related farm injuries in a population-based, case-control study. Cases had to reside in a defined geographic region served by a single medical center. Multiple sources reported cases, and a special farm census enabled random selection of controls, The annual risk of farm fall injury was 7.5 (95% CI: 5.7, 10.0) per 1,000 person-years. The crude incidence rate was higher in men, while the rate based on hours of farmwork was higher in women. In a multivariate analysis of risk factors, three factors were significantly associated with the risk. The risk of fall injury increased 2% (95% CI: 1%, 4%) per hour worked. Residents of farms with some farm workers not living on the farm had a fall injury rate 2.5 (95% CI: 1.0, 6.2) times greater than residents of other farms. Residents of farms with registered cows had one-third (95% CI: 0.14, 0.93) the risk of residents of other farms. To identify environmental hazards for fall injuries, researchers from several disciplines may need to collaborate in the design and conduct of studies that include injury site investigations.

Angiogenin single-chain immunofusions: influence of peptide linkers and spacers between fusion protein domains

The gene for human angiogenin (Ang), a member of the ribonuclease superfamily, was fused to a gene encoding a single-chain antibody (sFv) against the human transferrin receptor. Three Ang single-chain immunofusion proteins (AngsFvs) were constructed with variations in the type of linker connecting the VL and VH chain [EGKSSGSGSESKEF, L1 or (GGGGS)3, L2] as well as with or without a spacer (FB) connecting the Ang and sFv (AngFBsFvL1 or L2; AngsFv(L2)]. Although the nature of the linker did not affect the enzymatic activity of the FB-containing fusion proteins, the fusion protein containing the L2 linker was 2.3-fold more effective than the L1 linker in competing with the labeled monoclonal IgG1 antibody for binding to the transferrin receptor. The fusion protein containing the L2 linker without the FB spacer exhibited a 13-fold decrease in binding to the transferrin receptor as well as a decrease in its capacity to degrade tRNA and to inhibit translation in the rabbit reticulocyte lysate compared to its counterpart containing the FB spacer. Binding of placental ribonuclease inhibitor (PRI) to Ang also was affected by the nature of the linker and by the presence or absence of a spacer. PRI bound to Ang and AngFBsFv(L2) and inhibited their ribonuclease activity. A 3-fold greater concentration of PRI, however, did not affect the activity of AngFBsFv(L1) or AngsFv(L2), suggesting that the conformation of these fusion proteins was altered. Binding of monoclonal and polyclonal anti-Ang antibodies to AngsFvs was also used to investigate conformational alterations of the fusion proteins. AngFBsFv(L2) was the least altered while AngFBsFv(L1) exhibited the greatest change in structure. Yet maximal concentrations of all AngsFvs elicited angiogenesis in the chick chorioallantoic membrane assay, demonstrating that Ang in all three fusion proteins remained functionally active. Consistent with all the activities, the fusion protein containing the FB spacer and L2 linker was the most cytotoxic to three different human tumor cell lines. The fusion protein lacking the FB spacer exhibited the least cytotoxicity. These data demonstrate that the linker connecting the VH-VL chains can affect the binding and cellular cytotoxicity of Ang immunofusions and that placement of a spacer between the antibody binding domains and Ang is necessary for optimal activity. Thus, a new class of targeted therapeutic agents containing Ang as the toxic moiety can be designed that potentially will be less immunogenic and less toxic than immunotoxins available currently.

Machine-related occupational injuries in farm residents

Farm machinery is an important contributor to the high rates of occupational injury in agriculture. As part of a population-based case-control study, we studied risk factors for machine-related farm injuries. Case patients were farm residents residing in a geographically defined area of central Wisconsin who experienced a farm injury associated with a tractor, farm implement, or other machine which required medical or chiropractic care from May 1990 through April 1992. Controls were selected from an ad hoc census of farm residents in the same area. Telephone interviews regarding demographic characteristics, safety behaviors, and farming practices were completed for 97.8% of 90 case patients and for 82.8% of 221 control subjects. Personal characteristics significantly associated with an increased risk of machine-related injury included the number of hours worked per week and working primarily as a farmer. Dairy farms, farms with nonresident workers, and large farms were associated with an increased risk of injury while farms with registered cows and farms where cows were fed in the barn even in summer experienced fewer injuries. Based on a logistic regression model, the independent risk factors for machine-related farm injury included hours worked per week (2% increased risk/nonresident workers on farm (odds ratio) (OR) = 2.32; 95% confidence interval (CI): 1.07 to 5.06), cows fed in barn in summer (OR = 0.28; 95% CI: 0.12 to 0.64), and registered cows on farm (OR = 0.36; 95% CI: 0.17 to 0.79). Farm safety practices did not appreciably influence the risk of machine-related farm injury.

Incidence of farm-work-related acute injury in a defined population

To determine occurrence and sources of farm-work-related injury, we conducted a population-based, prospective study in a large clinic and hospital serving a defined rural area. The population at risk was identified through a unique demographic and medical records linkage system and a special agricultural census. Cases were 510 individuals who sought inpatient or outpatient care from May 1990 through April 1992 from a physician or chiropractor for harm resulting from acute exposure to energy. One per 31 farm residents was treated annually for a farm-work-related injury. Eight percent of these cases were hospitalized. Animals were the most frequent source of injury. Severity did not differ between cases associated with animals, machinery, falls, or chemicals. Thirty-eight percent of farm-work-related injury cases occurred in nonfarm residents. Injury risk was 2.5 times greater among dairy farm residents than among nondairy farm residents, 352.0 vs. 141.0 cases per 10,000 person-years, respectively. Adult male farm residents had 556.9 injuries per 10,000 person-years and 21.3 injuries per million hours of farm work.

Prognostic factors of spinal cord stimulation for chronic back and leg pain

Spinal cord stimulation (SCS) has been used for more than 20 years in the treatment of diverse pain conditions. Although recent studies have identified more clearly those conditions for which SCSoffers a favorable prognosis, the identification of a patient population in whom reasonably long-term success can be expected has been difficult. In an effort to improve patient selection and increase the overall success rate of treatment, we have examined various physical, demographic, and psychosocial variables as predictors of SCS outcome. The study population consisted of 40 patients with chronic low back and/or leg pain, 85% of whom were diagnosed with failed back surgery syndrome. Medical history and demographic data were collected as part of an initial assessment along with patient responses to the Minnesota Multiphasic Personality Inventory, the visual analogue pain rating scale (VAS), the McGill Pain Questionnaire, the Oswestry Disability Questionnaire, the Beck Depression Inventory, and the Sickness Impact Profile. Treatment outcomes were examined and found to improve significantly after 3 months of stimulation. Subsequent regression analysis revealed that patient age, the Minnesota Multiphasic Personality Inventory depression subscale D, and the evaluative subscale of the McGill Pain Questionnaire (MPQe) were important predictors of posttreatment pain status. Increased patient age and D subscale scores correlated negatively with pain status, as measured by the percentage of changes in pretreatment and posttreatment VAS scores, % delta VAS. In contrast, higher MPQe correlated with improved pain status. By the use of the following equation and the definition commonly associated with SCS success (at least 50% decrease in the VAS pain level), the success or failure of 3 months of SCS was correctly predicted in 88% of the study population. Our results suggest that patient age, Minnesota Multiphasic Personality Inventory depression, and MPQe may be clinically useful in the prediction of pain status after 3 months of SCS in patients with chronic low back and/or leg pain. % delta VAS = 112.57 - 1.98 (D)-1.68 (Age) + 35.54 (MPQe).

Angiogenin antagonists prevent tumor growth in vivo

A noncytotoxic neutralizing monoclonal antibody (mAb), 26-2F, to human angiogenin (Ang), a potent inducer of neovascularization, has been reported to prevent or delay the establishment of HT-29 human tumor xenografts in athymic mice. In the present study the tumor model was modified to increase sensitivity to Ang antagonists to facilitate further investigations and comparisons of their capacity to inhibit tumor growth. An increase in the percentage of tumor-free mice from 10-25% to 65% is observed in this modified model after treatment with mAb 26-2F. An additional neutralizing mAb, 36u, that interacts with a different epitope on Ang similarly prevents the appearance of tumors, both alone and in combination with mAb 26-2F. In those tumors that develop in mice treated with these agents, the number of vascular elements is reduced. Actin, an Ang antagonist that unlike the mAbs binds both human and mouse Ang, also prevents the establishment of tumors while exhibiting no toxic effects at daily doses > 50 times the molar amount of circulating mouse Ang. Ang antagonists also inhibit the appearance of tumors derived from two other Ang-secreting human tumor cell lines--i.e., A549 lung adenocarcinoma and HT-1080 fibrosarcoma. These results demonstrate that inhibition of the action of Ang is an effective therapeutic approach for the treatment of malignant disease.

Preserved cognitive skills in dementia of the Alzheimer type

OBJECTIVE

To describe preserved cognitive skills in patients with dementia.

DESIGN

Case series.

SETTING

Community clinic.

PATIENTS

Five patients who met National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria for probable Alzheimer's disease and were claimed to retain a cognitive skill.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Standard neuropsychological tests and individualized measures of patient's skilled behaviors. For patients who remained skilled at games, performance was compared with that of normal controls in direct competition. For the patient-trombonist, raters compared premorbid and postmorbid recordings of his play.

RESULTS

One patient continued to play the trombone in a Dixieland band, although he could not name well-known numbers that he played. Another continued to solve adult jigsaw puzzles. A third patient retained skill at canasta, the fourth at dominoes. The fifth patient remained a skillful contract bridge player, although he could not name the suits or articulate simple bidding rules. Four patients had impaired performance on standard anterograde and remote memory and naming tests but performed normally on pursuit rotor and letter fluency tests. Mini-Mental State Examination scores for these patients ranged from 10 to 22. One patient refused neuropsychological testing but displayed his skill.

CONCLUSIONS

Together with previous studies of preserved piano playing or painting skills, our findings indicate that a broad range of complex cognitive abilities may be preserved in patients with dementia of the Alzheimer type who cannot perform simpler actions.

A monoclonal antibody to human angiogenin suppresses tumor growth in athymic mice

Human angiogenin, a potent inducer of neovascularization, is secreted by HT-29 colon adenocarcinoma cells. microgram doses of a monoclonal antibody that neutralizes the in vitro and in vivo activities of angiogenin prevent or delay the appearance of s.c. HT-29 tumors in athymic mice in a statistically significant, dose-dependent manner. The antibody is not cytotoxic to tumor cells in vitro, which indicates that inhibition of tumor growth most likely occurs by neutralization of the activity of angiogenin in vivo and further implies a critical role for angiogenin in the early development of HT-29 tumors. The results suggest a therapeutically useful approach to the treatment of angiogenin-dependent malignancy.

A monoclonal antibody to human angiogenin. Inhibition of ribonucleolytic and angiogenic activities and localization of the antigenic epitope

A monoclonal antibody (mAb) to human angiogenin, a protein that induces formation of new blood vessels, was produced by somatic cell fusion techniques and designated as 26-2F. It is an IgGl kappa whose binding affinity, expressed as an IC50, is (1.6 +/- 0.1) x 10(-9) M as determined by a competition radioimmunoassay. mAb 26-2F neutralizes the ribonucleolytic activity of angiogenin as assessed by in vitro protein synthesis and tRNA degradation assays. It also effectively inhibits neovascularization induced by angiogenin on the chick chorioallantoic membrane. Epitope mapping indicates that the binding region of angiogenin recognized by mAb 26-2F is discontinuous and involves both Trp-89 and residues in the segment 38-41. This epitope is formed by two surface loops which are juxtaposed in the three-dimensional structure of human angiogenin recently determined by X-ray crystallography. Thus mAb 26-2F, along with similar antibodies under investigation, will facilitate structure/function studies of angiogenin, help define its physiological role, and lead to an understanding of the consequences of its inhibition in pathological situations in which angiogenin may be involved.

Practice satisfaction and dissatisfaction in general internal medicine departments of large multispecialty clinics

General internal medicine (GIM) physician practice satisfaction and dissatisfaction in large multispecialty clinics were assessed utilizing a survey designed to elicit physician perceptions of practice. 420 GIM physicians in 22 multispecialty clinics were contacted, and 168 participated in the survey. The most significant positive components of practice satisfaction were patient interactions and favorable physician colleague interactions. The prominent negative components were paperwork hassles and perceived "second-class" physician status. Coping strategies were varied and included increased political involvement, career change, and withdrawal via depression.

Prognosis of photoparoxysmal response in nonepileptic patients

Photoparoxysmal response (PPR) is sometimes incidentally encountered in EEGs performed for evaluation of nonepileptic symptoms. We conducted the first long-term study of a cohort of nonepileptic patients to determine their risk of having seizures subsequent to incidental recording of PPR. After 6 to 12 years (mean, 9 years), none of the 33 patients had had epileptic seizures. To identify prognostic factors associated with PPR, we performed a case-control study comparing the cohort with 33 age-matched patients who had had epileptic seizures prior to PPR recording. There was no statistically significant difference between the two groups with respect to the clinical or EEG data. Morphology of the PPR discharge was not different between the two groups. Contrary to what is widely believed, persistence of PPR discharges beyond stimulation was not associated with a high risk of developing seizures. Prognosis of PPR is age-dependent and seems favorable in adults without previous epileptic seizures.

Placebo-controlled evaluation of Ritalin side effects

OBJECTIVE

To address the frequency of side effects of Ritalin therapy in children with attention deficit hyperactivity disorder (ADHD) using the Barkeley Side Effects Questionnaire (BSEQ) in a clinical setting.

DESIGN

Randomized double-blind placebo-controlled cross-over trial.

SETTING

A large rural tertiary care clinic.

PATIENTS

234 consecutive children aged 5 through 15 years who met the Diagnostic and Statistical Manual of Mental Disorders (3rd ed, revised) criteria for ADHD were enrolled. Of these children, 206 had sufficient side effects data for analysis.

INTERVENTIONS

0.3 mg/kg per dose and 0.5 mg/kg per dose Ritalin compared to placebo in separate 2-week trials. Each treatment was given three times a day for 7 consecutive days.

MEASUREMENTS AND MAIN RESULTS

Parents, blinded to the treatment assignment, assessed side effects via the BSEQ at baseline and at the end of each of the 4 treatment weeks. Univariate odds ratios (OR) were used to describe the magnitude of differences in observed side effects between Ritalin and placebo weeks of the trial for each of the items on the BSEQ. The frequency of the following side effects significantly increased with Ritalin therapy: insomnia (OR = 3.13, 95% confidence interval [CI] = (1.80,5.42)), appetite disturbance (OR = 19.00, 95% CI = (9.18,39.31)), stomachache (OR = 7.00, 95% CI = (3.29, 14.89)), headache (OR = 5.29, 95% CI = (2.51,11.15)), and dizziness (OR = 7.50, 95% CI = (1.93,29.13)). The frequency of the following side effects significantly decreased with Ritalin therapy: staring and daydreaming (OR = 0.47, 95% CI = (0.27,0.84)), irritability (OR = 0.33, 95% CI = (0.18,0.61)), anxiety (OR = 0.42, 95% CI = (0.23,0.76)), and nailbiting (OR = 0.19, 95% CI = (0.07, 0.53)). The incidence rates of the remaining BSEQ items did not differ significantly between the Ritalin and placebo weeks of the trial.

CONCLUSION

The BSEQ proved to be clinically effective in tracking Ritalin side effects and should be incorporated into the routine evaluation and monitoring of ADHD patients for whom stimulants are prescribed.

Influence of pupil size, anisocoria, and ambient light on pilocarpine miosis. Implications for supersensitivity testing

BACKGROUND

This study determines how pupil size, anisocoria, and ambient light influence miotic responses to dilute pilocarpine. The aim is to establish whether mechanical properties of the iris affect miotic behavior using a cholinergic agonist and, if so, to define a more specific clinical definition of supersensitivity testing for suspected tonic pupil disorders.

METHODS

The right pupil of 42 normal subjects was first dilated with phenylephrine to create an experimental anisocoria. Then, pilocarpine 0.1% was placed in both eyes. Net constriction of the larger right pupil was determined by subtracting the amount of pilocarpine-induced constriction of the control left pupil from the amount of pilocarpine-induced constriction of the experimental right pupil. Pupil diameters were measured in room light and darkness.

RESULTS

In only a few subjects, the larger right pupil became smaller than the left pupil after pilocarpine administration. Net constriction of the right pupil was greater when determined in room light than in darkness. The amount of net constriction of the right pupil showed good correlation with the degree of baseline anisocoria when evaluated in room light, but not so in darkness.

CONCLUSION

Pupil size, degree of anisocoria, and light conditions influence the amount of pilocarpine-induced change in anisocoria. If a patient's larger pupil becomes the smaller pupil in darkness after dilute pilocarpine is applied to both eyes, then it is likely that such a response occurred independent of mechanical properties of the iris, and likely represents a supersensitive response. Ophthalmology.

Pelvic and para-aortic lymphadenectomy for surgical staging of endometrial cancer: morbidity and mortality

This analysis compared retrospectively the morbidity and mortality of patients with endometrial cancer who had total abdominal hysterectomy with bilateral salpingo-oophorectomy (TAH/BSO) alone or with pelvic and para-aortic lymphadenectomy performed by the same surgeon at one private institution. Between August 1987 and March 1991, 77 women with endometrial cancer were staged surgically by a standard protocol without preoperative radiotherapy. Thirty-five patients (45%) had TAH/BSO alone and 42 (55%) had TAH/BSO with pelvic and para-aortic lymphadenectomy. The median number of lymph nodes removed was 18. Patients having lymphadenectomy had an increased mean (+/- standard deviation) operative time (129 +/- 29 versus 87 +/- 26 minutes; P less than .0001), increased mean estimated blood loss (391 +/- 192 versus 272 +/- 219 mL; P = .013), and a longer postoperative hospital stay (P = .017) compared with patients having TAH/BSO alone. However, there was no difference in transfusion rate, febrile morbidity, postoperative complications, or mortality. We conclude that pelvic and para-aortic lymphadenectomy can be added to TAH/BSO in patients with endometrial cancer without a clinically significant increase in morbidity or mortality.

Impaired critical flicker frequency in recovered optic neuritis

Thirteen patients with optic neuritis who recovered normal visual acuity and kinetic perimetry all showed impairment of foveal critical flicker frequency, a psychophysical test of visual temporal resolution. Because the magnocellular visual system demonstrates higher temporal resolution than the parvocellular system, this finding implicates involvement of axonal projections of magnocellular retinal ganglion cells in recovered optic neuritis.

General internal medicine practice trends in large multispecialty clinics

OBJECTIVE

To assess practice trends in the general internal medicine departments of large multispecialty clinics.

DESIGN

A survey questionnaire addressing the following issues: 1) department size and rate of growth, 2) services provided, 3) patient population, 4) individual clinical workload, 5) call arrangements, 6) time away from practice, and 7) benefits and salary.

PARTICIPANTS

22 multispecialty clinics, with a mean of 279 physicians.

MEASUREMENTS AND RESULTS

Mean general internal medicine department physician expansion was 28% over the preceding three years. Primary care, clinic system access, care of patients laterally shifted from subspecialty internists, and preoperative evaluations were the four major services provided. The mix of fee-for-service, Medicare/Medicaid, and prepaid-plan patients was diverse. Mean outpatient clinical scheduling was 35 hours per week exclusive of hospital practice, administrative time, and paperwork. Study of call arrangements revealed a definite trend toward a group practice model of shared responsibility during the day as well as nights and weekends. Mean meeting and vacation time was 35 days per year. Salary was set by committee, formula, or both. Department stresses and dissatisfactions were also reported.

CONCLUSIONS

Rapid expansion of general internal medicine departments and services will continue as subspecialists back away from providing primary care. The evolution of general internal medicine practice must be anticipated and managed for optimal patient and departmental outcomes.

Computed tomography ventricular size has no predictive value in diagnosing pseudotumor cerebri

We compared linear indices of computed tomography ventricular size in patients with pseudotumor cerebri and in age-matched controls, and found no difference between these populations. Two physicians showed poor agreement and sensitivity when blindly judging whether patients and controls had "slit-like" ventricles. We conclude that ventricular size on routine CT has no predictive value when evaluating patients with suspected pseudotumor cerebri.

Expression of human angiogenin in cultured baby hamster kidney cells

Baby hamster kidney cells were transformed with DNA sequences derived from the gene for human angiogenin. Expression was under the transcriptional control of the inducible mouse metallothionein 1 promoter. Recombinant angiogenin was purified and shown to be chemically, biologically, and enzymatically indistinguishable from the natural product. The large-scale production of recombinant angiogenin achieved should facilitate detailed studies into the structure-function relationships of this potent angiogenic molecule.

Isolation of angiogenin from normal human plasma

Angiogenin, a potent blood vessel inducing protein, was previously isolated from medium conditioned by a human adenocarcinoma cell line [Fett, J. W., Strydom, D.J., Lobb, R.R., Alderman, E.M., Bethune, J.L., Riordan, J.F., & Vallee, B.L. (1985) Biochemistry 24, 5480-5486]. We now report that a protein which is physically and functionally identical with angiogenin is present in normal human plasma and can be purified to homogeneity by CM 52 and Mono S cation-exchange chromatography. The plasma-derived angiogenin exhibits the same angiogenic and ribonucleolytic activities, amino acid composition, molecular weight, immunoreactivity, and chromatographic behavior as the tumor cell derived protein. Peptide mapping and sequencing studies indicate chemical identity of the two proteins. The present yield of angiogenin from either plasma or serum is 60-150 micrograms/L. These findings demonstrate that angiogenin is not a tumor-specific product and provide further opportunities for the investigation of the role and mechanism of action of angiogenin and its potential diagnostic or prognostic utility.

Tissue deposition of immune complexes in mice receiving daily injections of bovine serum albumin

The daily intraperitoneal injection of 0.3 mg of 0.5 mg BSA into preimmunized mice produced chronic serum sickness (CSS) within several weeks. The glomerulonephritis which developed was characterized in most cases (74%) by the deposition of immune complexes in the glomerular capillary wall. Associated pathological changes included crescent formation, hypercellularity, capillary occlusion and exudative and degenerative lesions in the glomeruli. In other animals (26%) a less severe renal disease developed in which immune complex deposition and histological abnormalities were limited to the glomerular mesangium. Mice with membranoproliferative immune complex glomerulonephritis had deposits of immune complexes in many other organs besides the kidney. A model of CSS in mice opens the possibility of studying the cellular basis of the immune response and genetic determinants in experimentally induced systemic immune complex disease.