Phosphorylation-induced rearrangement of the histone H3 NH2-terminal domain during mitotic chromosome condensation.

The NH2-terminal domain (N-tail) of histone H3 has been implicated in chromatin compaction and its phosphorylation at Ser10 is tightly correlated with mitotic chromosome condensation. We have developed one mAb that specifically recognizes histone H3 N-tails phosphorylated at Ser10 (H3P Ab) and another that recognizes phosphorylated and unphosphorylated H3 N-tails equally well (H3 Ab). Immunocytochemistry with the H3P Ab shows that Ser10 phosphorylation begins in early prophase, peaks before metaphase, and decreases during anaphase and telophase. Unexpectedly, the H3 Ab shows stronger immunofluorescence in mitosis than interphase, indicating that the H3 N-tail is more accessible in condensed mitotic chromatin than in decondensed interphase chromatin. In vivo ultraviolet laser cross-linking indicates that the H3 N-tail is bound to DNA in interphase cells and that binding is reduced in mitotic cells. Treatment of mitotic cells with the protein kinase inhibitor staurosporine causes histone H3 dephosphorylation and chromosome decondensation. It also decreases the accessibility of the H3 N-tail to H3 Ab and increases the binding of the N-tail to DNA. These results indicate that a phosphorylation-dependent weakening of the association between the H3 N-tail and DNA plays a role in mitotic chromosome condensation.

Pancreatitis as a complication of endovascular aneurysm repair.

INTRODUCTION: We report a case of acute pancreatitis complicating an endovascular abdominal aortic aneurysm repair (EVAR). REPORT: A seventy three year old man underwent an EVAR and developed acute onset epigastric pain, followed by mottling of the upper abdominal wall. A raised amylase confirmed the diagnosis of acute pancreatitis. DISCUSSION: To our knowledge this is the first report of this complication of EVAR.

Cell-based screen for antimitotic agents and identification of analogues of rhizoxin, eleutherobin, and paclitaxel in natural extracts.

We describe a cell-based assay for antimitotic compounds that is suitable for drug discovery and for quantitative determination of antimitotic activity. In the assay, cells arrested in mitosis as a result of exposure to antimitotic agents in pure form or in crude natural extracts are detected by ELISA using the monoclonal antibody TG-3. The assay was used to screen >24,000 extracts of marine microorganisms and invertebrates and terrestrial plants and to guide the purification of active compounds from 5 of 119 positive extracts. A new rhizoxin analogue was found in a Pseudomonas species, six new eleutherobin analogues were identified from the octocoral Erythropodium caribaeorum, and two paclitaxel analogues were found in the stem bark of the tree Ilex macrophylla. The assay was also used for quantitative comparison of the antimitotic activity of different analogues. It revealed the importance of the C-11 to C-13 segment of the diterpene core of eleutherobin for its antimitotic activity. The identification of antimitotic compounds in very low abundance and their high (0.5%) occurrence in natural extracts indicates that drug discovery efforts using this cell-based assay may lead to the identification of structurally novel antimitotic agents.

High-throughput assay for G2 checkpoint inhibitors and identification of the structurally novel compound isogranulatimide.

Treatment of cancer cells lacking p53 function with G2 checkpoint inhibitors sensitizes them to the toxic effects of DNA damage and has been proposed as a strategy for cancer therapy. However, few inhibitors are known, and they have been found serendipitously. We report the development of a G2 checkpoint inhibition assay that is suitable for high-throughput screening and its application to a screen of 1300 natural extracts. We present the isolation of a new G2 checkpoint inhibitor, the structurally novel compound isogranulatimide. In combination with gamma-irradiation, isogranulatimide selectively kills MCF-7 cells lacking p53 function.

Cytotoxic peptides hemiasterlin, hemiasterlin A and hemiasterlin B induce mitotic arrest and abnormal spindle formation.

PURPOSE: Hemiasterlin, hemiasterlin A and hemiasterlin B are newly isolated cytotoxic tripeptides with potential as antitumor drugs. We wished to determine their mechanism of cytotoxicity. METHODS: We studied their effect on cell survival, cell cycle progression, and microtubule morphology in MCF-7 human mammary carcinoma cells. RESULTS: At the nanomolar concentrations at which they were cytotoxic, the peptides induced arrest in mitotic metaphase. Hemiasterlin A produced abnormal mitotic spindles like those produced by the microtubule inhibitors taxol, nocodazole and vinblastine at low concentrations. At high concentrations hemiasterlin A did not cause microtubule bundling like taxol, but caused microtubule depolymerization like nocodazole and vinblastine. CONCLUSIONS: The hemiasterlins probably exert their cytotoxic effect by inhibiting spindle microtubule dynamics.

Characterization of cultured human nesidioblasts and their associated macromolecules: cross-reactivity with a cloned rat pancreatic beta-cell line.

Near-total pancreatectomy in a neonate presenting with persistent hypoglycemia offered an unusual opportunity to grow preparations enriched in beta-cells. Morphology, chromosomal analysis, and immunohistochemistry were used to characterize a subculture (Nesi B) that remained stable through passage 11. Insulin secretion of Nesi B was constitutive at 38-74 nU/microliters of medium/24 h, increasing modestly in the presence of isobutylmethylxanthine, an inhibitor of cyclic AMP phosphodiesterase. Endocrine cells, exclusive of those in islet regions, were widely distributed throughout the original tissue section, and immunostaining of the Nesi B subculture demonstrated well-differentiated heavily granulated insulin-positive cells, each with a normal modal number of chromosomes (46). Nesi B cell-associated macromolecules were isolated in 3 x 10(-3) ethylenedinitrilotetraacetate/phosphate-buffered saline and were found to be reactive with a heterologous immune serum elicited to a cloned rat pancreatic beta-cell line (RIN-5F). Western (immuno) blotting showed this immunoreactivity to reside primarily in a 95-kDa fraction of Nesi B-derived components. These results indicate that human nesidioblasts can be cultured for a sufficient number of passages to allow isolation and immunochemical characterization of pancreatic beta-cell macromolecules shared between rat and human and that may serve as organ-specific antigens for inflammatory disorders of the pancreas.

Scintimammography: a pictorial review of the variable normal, post surgical and pathological appearances.

Scintimammography has a high specificity and sensitivity for the detection of primary and metastatic breast carcinoma and in the evaluation of the postoperative breast. This review highlights the spectrum of pathological features as well as the normal postoperative and postreconstruction changes and the variable normal appearances that may be encountered with this technique.

Evaluation of rapid antibody dissociation techniques.

Two new antibody dissociation techniques, citric acid treatment and chloroquine diphosphate (CDP) treatment at 37 C, were evaluated for their usefulness in investigating the red cells of patients with a positive direct antiglobulin test (DAT). The techniques were compared to the ZZAP and CDP-22 C procedures for (a) removal of coating antibody prior to performing warm autoadsorptions, and (b) removal of antibody so antigen typings can be performed. Twenty patient or donor antibodies were used to sensitize red cells in vitro. Complete removal of antibody was obtained by the CDP-37 C treatment in 19 cases (95%), by ZZAP treatment in 17 cases (8 5%), by the citric acid method in 10 cases (50%), and by the CDP-22 C method in three cases (15%). The CDP-37 C treatment left all red cell antigens investigated intact, and the citric acid technique left all but Kell system antigens intact. In addition, patient red cells treated by the citric acid technique could be used to adsorb warm-reacting autoantibodies from autologous serum in 15 to 30 minutes at room temperature. Investigation of a positive DAT may be facilitated by using the citric acid and CDP-37 C treatments.

Extracranial internal carotid artery aneurysm presenting as symptomatic hypoglossal and glossopharyngeal nerve paralysis.

Aneurysms of the extracranial portion of the internal carotid artery are rare, particularly in young patients. They usually develop following trauma, or secondary to infection involving the parapharyngeal space that extends to the vessel wall. This is a case of an internal carotid artery aneurysm presenting acutely following chiropractic neck manipulation with hypoglossal and glossopharyngeal nerve palsy. The imaging findings and subsequent operative management are described.

A guide to HFMA's certification process.

HFMA's professional certification process offers members a way to demonstrate their expertise in patient accounts management or healthcare financial management. Marsha L. Morien, FHFMA, CMPA, is chairman of HFMA's Board of Examiners, the group that oversees the certification activities. In the following interview, Morien explains the steps in the process and offers advice for members preparing to become certified.

Patient accounts managers share views on receivables.

Hospitals can take several steps to improve the management of receivables, according to eight patient accounts managers recently interviewed. Among these steps are precisely identifying problem areas and devising solutions; automating as many business office functions as possible; gathering more patient data before hospital admissions; and developing a well-trained and motivated staff. The managers interviewed, however, do not expect substantial improvement in hospitals' days outstanding in receivables in the year ahead. And they do not view selling receivables as a permanent solution to cash flow problems.

The battle between Unix and Windows NT.

For more than a decade, Unix has been the dominant back-end operating system in health care. But that prominent position is being challenged by Windows NT, touted by its developer, Microsoft Corp., as the operating system of the future. CIOs and others are attempting to figure out which system is the best choice in the long run.

A catalyst for the networking movement.

Charles Jones has a clear vision for how community health information networks can improve health care delivery in West Virginia. He's seen what EDI has done for retailing and manufacturing industries. Now, he's trying to turn his dreams into reality by heading a consortium that's developing a strategy for building several networks in the state. Jones is demonstrating how one hospital executive with strong personal convictions can spark a sweeping effort to change the way a state health care system functions.