Diazonamide A and a synthetic structural analog: disruptive effects on mitosis and cellular microtubules and analysis of their interactions with tubulin

The marine ascidian Diazona angulata was the source organism for the complex cytotoxic peptide diazonamide A. The molecular structure of this peptide was recently revised after synthesis of a biologically active analog of diazonamide A in which a single nitrogen atom was replaced by an oxygen atom. Diazonamide A causes cells to arrest in mitosis, and, after exposure to the drug, treated cells lose both interphase and spindle microtubules. Both diazonamide A and the oxygen analog are potent inhibitors of microtubule assembly, equivalent in activity to dolastatin 10 and therefore far more potent than dolastatin 15. This inhibition of microtubule assembly is accompanied by potent inhibition of tubulin-dependent GTP hydrolysis, also comparable with the effects observed with dolastatin 10. However, the remaining biochemical properties of diazonamide A and its analog differ markedly from those of dolastatin 10 and closely resemble the properties of dolastatin 15. Neither diazonamide A nor the analog inhibited the binding of [3H]vinblastine, [3H]dolastatin 10, or [8-14C]GTP to tubulin. Nor were they able to stabilize the colchicine binding activity of tubulin. These observations indicate either that diazonamide A and the analog have a unique binding site on tubulin differing from the vinca alkaloid and dolastatin 10 binding sites, or that diazonamide A and the analog bind weakly to unpolymerized tubulin but strongly to microtubule ends. If the latter is correct, diazonamide A and its oxygen analog should have uniquely potent inhibitory effects on the dynamic properties of microtubules.

Evaluating Electronic Local Government in the Uk

An array of UK government initiatives have been launched since 1997, collectively being known as the local government modernization agenda. This can be seen as an attempt to transform the structures and performance of local authorities in the UK. A parallel set of initiatives, the electronic government agenda, were launched in 2000 and have attempted to extend the use of information and communication technologies (ICTs) within local government. This paper describes the context for and themes within both agendas, the aim being to describe the existing and likely dynamics of the relationship between innovations in ICTs within local government and the modernization of local government. The paper presents an analysis of the electronic government strategies of 22 Welsh unitary authorities and uses this analysis for highlighting a number of issues relating to the progress of the electronic local government agenda within the UK. The paper concludes with a call for longitudinal investigation in this area.

Antineoplastic agents. 485. Isolation and structure of cribrostatin 6, a dark blue cancer cell growth inhibitor from the marine sponge Cribrochalina sp

Cribrostatin 6, a dark blue cancer cell growth inhibiting (P388 ED(50) 0.3 microg/mL) constituent of the Republic of Maldives marine sponge Cribrochalina sp., has been assigned structure 3 on the basis of a combination of HRMS, high-field (500 MHz, HMBC, and GOESY experiments) (15)N, (1)H, and (13)C NMR, and X-ray crystal structure analyses. Cribrostatin 6 also was found to inhibit the growth of a number of pathogenic bacteria and fungi.

Rectal duplication cyst in an adult: the laparoscopic approach

BACKGROUND

Rectal duplication cyst (RDC) is a rare congenital anomaly representing 1% to 8% of all intestinal duplications. The case presented here is the first report of the laparoscopic resection of an RDC.

METHODS

We report the case of a 49-year-old white woman in whom a retrorectal cystic mass measuring 5 x 5.3 x 6 cm was diagnosed. The mass was completely resected by means of laparoscopic techniques.

RESULTS

Pathologic findings revealed a cystic structure partially lined with squamous as well as respiratory- and gastrointestinal-type epithelium. Muscularis propria was identified in the outer portions of the wall of the specimen. No atypia or malignancy was identified. The overall findings were consistent with an RDC.

CONCLUSIONS

Laparoscopic resection constitutes an excellent and patient-friendly approach to the management of large adult cystic duplication of the rectum.

Laparoscopic ventral hernia repair during the learning curve

Large series of laparoscopic ventral hernia repair have shown excellent results. However, published comparative studies have had conflicting outcomes. We retrospectively reviewed the first 29 laparoscopic ventral hernia repairs performed at a VA Medical Center from January 2000 to June 2001. The outcome was compared to that of open repairs performed during the same time period. Outcomes between the groups were similar in all respects, except for the length of stay. The conversion rate for the laparoscopic approach was 13.8%. There was one death in the laparoscopic group due to an unrecognized enterotomy. There were three recurrences in the open group and one in the laparoscopic group with a mean follow up of 13 months. In our series, laparoscopic hernia repair resulted in a shorter hospital stay but no other significant benefits, along with a risk of missed enterotomy. The risk-benefit ratio for this procedure may be high during the learning curve.

The investigation and management of neonatal haemostasis and thrombosis

These guidelines address developmental aspects of neonatal haemostasis and thrombosis, the laboratory investigation of the neonate, and the diagnosis and clinical management of haemostatic and thrombotic conditions occurring in this period (defined as the first 4 weeks of life following birth). Relevant scientific papers were identified by a systematic literature review from Medline 1975-2000 using index terms which incorporated the various component subjects of these guidelines. Further publications were obtained from the references cited and from reviews known to the members of the working party and to the Haemostasis and Thrombosis Task Force. Evidence and graded recommendations presented in these guidelines are in accordance with the US Agency for Health Care Policy and Research, as described in the Appendix. It will be noted that there is a lack of a strong evidence base for many of the recommendations suggested, as the appropriate clinical and laboratory trials have not been and perhaps never will be undertaken in neonates. Most of the recommendations are therefore of Grade C evidence levels IV: higher levels are mentioned specifically throughout the document when relevant.

The investigation and management of neonatal haemostasis and thrombosis

These guidelines address developmental aspects of neonatal haemostasis and thrombosis, the laboratory investigation of the neonate, and the diagnosis and clinical management of haemostatic and thrombotic conditions occurring in this period (defined as the first 4 weeks of life following birth). Relevant scientific papers were identified by a systematic literature review from Medline 1975-2000 using index terms which incorporated the various component subjects of these guidelines. Further publications were obtained from the references cited and from reviews known to the members of the working party and to the Haemostasis and Thrombosis Task Force. Evidence and graded recommendations presented in these guidelines are in accordance with the US Agency for Health Care Policy and Research, as described in the Appendix. It will be noted that there is a lack of a strong evidence base for many of the recommendations suggested, as the appropriate clinical and laboratory trials have not been and perhaps never will be undertaken in neonates. Most of the recommendations are therefore of Grade C evidence levels IV: higher levels are mentioned specifically throughout the document when relevant.

Reconstruction challenge--combined use of pectoralis major and gastric pull-up flaps for massive naso-oropharyngeal/oesophageal defects

Massive defects of the upper aerodigestive tract present a reconstructive challenge. We report a case in which a large defect of the naso-oropharyngeal and oesophagus was reconstructed with a combination of a gastric pull-up and a pectoralis major muscle flap. Postoperative function was good and survival was in excess of 16 months. The history of such reconstructions and possible alternative techniques are also discussed.

Nasopharyngectomy for recurrent nasopharyngeal carcinoma: a review of 31 patients and prognostic factors

OBJECTIVES/HYPOTHESIS

Nasopharyngectomy is a well-established treatment option for recurrent nasopharyngeal carcinoma. Over a period of 4 years and 3 months, in a total of 43 patients, 45 nasopharyngectomies were performed. Thirty-one patients with follow-up ranging from 12 to 58 months were studied. Twenty-two patients (58%) survived; of these, 18 patients (82%) remained disease free. All patients who developed repeat recurrence or died (n = 12) had a high recurrent T-stage tumor, skull base involvement, multiple recurrences, positive surgical margins, or concurrent neck node metastasis. These factors are poor prognostic parameters and might mitigate the indications for aggressive salvage surgery. However, low recurrent T-stage tumor without neck metastasis carries a good prognosis. Modern minimally invasive surgery carries minimal morbidity. STUDY DESIGN A retrospective study was made to determine prognostic indicators in patients treated with salvage surgery for recurrent nasopharyngeal carcinoma.

METHODS

Medical records were analyzed for all patients who had received nasopharyngectomy for recurrent nasopharyngeal carcinoma from March 1997 to June 2001. They were followed up from March 1997 to January 2002. Recurrent T stage, nodal metastasis, surgical approach, surgical margins, and pathological nodal status, together with surgical mortality, morbidity, and the delivery of postoperative irradiation, were compared with survival.

RESULTS

In all, 43 patients underwent 45 nasopharyngectomies over a period of 4 years and 3 months. Patients with less than 1 year of follow-up were excluded. Four patients with residual disease, who represent a more favorable group, and five patients with planned debulking, nasopharyngectomy, and postoperative stereotactic irradiation were also excluded. The study group comprised 25 men and 6 women (ratio of 4:1) with age ranging from 26 to 69 years (mean age, 49.5 y). In 28 patients (90.3%), the recurrence of nasopharyngeal carcinoma was their first recurrence; in 3 patients (9.7%), the recurrences were second recurrences. Twenty-two patients (71%) survived, achieving a mean survival of 28.5 months. Nine patients died with a mean interval of 7.8 months (range, 1-14 mo). Of the nine patients who died, six (67%) had T3 or T4 tumor, four (44.4%) had concurrent recurrent neck disease, and five (55.5%) had positive surgical margins. Two patients died of perioperative meningitis. Fifteen (83.3%) of the 18 disease-free survivors had a low recurrent T-stage tumor. Mean intervals for development of repeat recurrence or distant metastasis were 16 and 7.9 months, respectively.

CONCLUSIONS

High recurrent T stage, skull base involvement, repeated recurrence before surgery, nodal metastasis, and positive surgical margins carry a poor prognosis. This is particularly evident with high T stage and concurrent nodal metastasis. However, patients with low T stage have a survival advantage and benefit most from surgical treatment.

Tracheal necrosis and surgical emphysema: a rare complication of thyroidectomy

We describe the first reported case of tracheal necrosis following a thyroidectomy. This complication resulted in massive subcutaneous emphysema and pneumomediastinum, which required emergency exploration of the neck to decompress the trapped air. We also discuss the suggested etiology and management of this rare condition.

Tracheal Necrosis and Surgical Emphysema: A Rare Complication of Thyroidectomy

We describe the first reported case of tracheal necrosis following a thyroidectomy. This complication resulted in massive subcutaneous emphysema and pneumomediastinum. which required emergency exploration of the neck to decompress the trapped air. We also discuss the suggested etiology and management of this rare condition.

Successful treatment of congenital thrombotic thrombocytopenic purpura using the intermediate purity factor VIII concentrate BPL 8Y

There is increasing evidence that congenital thrombotic thrombocytopenic purpura (TTP) is caused by an absolute deficiency of von Willebrand factor-cleaving protease. The recent identification of this protease and the development of assays for its detection have enabled its quantification in a number of plasma products, including some commercial intermediate-purity plasma-derived factor VIII preparations. We report the successful, weekly prophylactic use of a commercial intermediate-purity plasma-derived factor VIII concentrate in the treatment of a 14-year-old girl with severe congenital TTP who had previously required transfusions of fresh-frozen plasma every 2 weeks from the age of 4 months.

Isolation and structure of pedilstatin from a republic of maldives Pedilanthus sp

A new cancer cell growth inhibitor designated pedilstatin (1) was isolated from a Republic of Maldives Pedilanthus sp. The structure was determined to be 13-O-acetyl-12-O-[2'Z,4'E-octadienoyl]-4alpha-deoxyphorbol on the basis of high-resolution mass spectral and 2D NMR assignments. Pedilstatin was found to significantly inhibit growth of the P388 lymphocytic leukemia cell line with an ED(50) of 0.28 microg/mL, to afford, at concentrations of 2-5 microM, protection (to 80%) of human-derived lymphoblastoid CEM-SS cells from infection and cell-killing by HIV-1, and to show inhibition of protein kinase C with a K(i) of 620 +/- 20 nM.

Identification, structural analysis and function of hyaluronan in developing fish larvae (leptocephali)

Hyaluronan (HA) has been identified as the principal glycosaminoglycan (CAG) in the highly hydrated, extracellular body matrix of the larval stage (leptocephalus) of seven species of true eels (Teleostei: Elopomorpha: Anguilliformes) and the ladyfish Elops saurus (Elopiformes), and was found as a minor GAG component in the bonefish Albula sp. (Albuliformes). Identification was based on: (1) HPLC separation of unsaturated disaccharides derived from chondroitinase ABC digests of whole-body GAG extracts; (2) 1H NMR analyses of native GAG polymers; and (3) degradation of GAG extracts by Streptomyces hyaluronan lyase. The unsaturated disaccharide 2-acetamido-2-deoxy-3-O-(beta-D-gluco-4-enepyranosyluronic acid)-D-glucose (DeltaDi-HA) accounted for 92.4-99.8% of the total disaccharides in chondroitinase digests. Trace amounts of unsaturated disaccharides of chondroitin sulfate were also present. Two-dimensional gCOSY spectra of the native HA polymer were similar for all species. Proton assignments for the HA disaccharide repeat (GlcAbeta1-3GlcNAcbeta1-4) in D(2)O, based on gCOSY, DQF-COSY and TOCSY analyses for the eel Ahlia egmontis, were concordant with published chemical shifts for HA oligosaccharides. In addition to its presumed role in maintaining the structural integrity and hydration of the gelatinous body of the leptocephalus, HA is postulated to function as a storage polysaccharide in those species in which it is the predominant GAG.

Tuberculosis and wound healing in head and neck cancer

Globalization of tuberculosis was noted, especially in immunomodulated patient. Patients having tuberculosis involving the cervical lymph nodes, undergoing resection for squamous cell carcinoma of the head and neck region would impact a detrimental effect to the surgery. We report 3 cases that had caused significant morbidity in post resection period.

Knockout mice heterozygous for Sod2 show alterations in cardiac mitochondrial function and apoptosis

Heart mitochondria from heterozygous (Sod2(-/+)) knockout mice have a 50% reduction in manganese superoxide dismutase (MnSOD) activity. The decrease in MnSOD activity was associated with increased mitochondrial oxidative damage as demonstrated by a decrease in the activities of iron sulfhydryl proteins sensitive to oxygen stress (aconitase and reduced nicotinamide adenine dinucleotide-oxidoreductase). Mitochondrial function was altered in the Sod2(-/+) mice, as shown by decreased respiration by complex I and an increase in the sensitivity of the permeability transition to induction by calcium and t-butylhydroperoxide. The increased induction of the permeability transition in heart mitochondria from Sod2(-/+.)mice was associated with increased release of cytochrome c and an increase in DNA fragmentation. Cardiomyocytes isolated from neonatal Sod2(-/+) and Sod2(-/-) mice were more sensitive to cell death than cardiomyocytes from Sod2(+/+) mice after t-butylhydroperoxide treatment, and this increased sensitivity was prevented by inhibiting the permeability transition with cyclosporin A. These experiments demonstrate that MnSOD may play an important role in the induction of the mitochondrial pathway of apoptosis in the heart, and this appears to occur primarily through the permeability transition.

Aberrant dimerization of von Willebrand factor as the result of mutations in the carboxy-terminal region: identification of 3 mutations in members of 3 different families with type 2A (phenotype IID) von Willebrand disease

The 3' end of the VWF gene was screened in the affected members of 3 different families with type 2A (phenotype IID) von Willebrand disease (vWD). Exons 49 to 52 of the VWF gene were amplified and screened for mutations by chemical cleavage mismatch detection. Mismatched bands were detected in exon 52 of 2 patients and in exon 51 of a third patient. Using direct DNA sequencing, a heterozygous G8562A transition leading to a Cys2008Tyr substitution was found in all the patients in family 1, and a T8561A transversion leading to a Cys2008Ser substitution was found in both patients from family 2. In a patient from a third family, an 8-base deletion from nucleotide 8437 to 8444 was identified in exon 51. The 2 mutations in exon 52 were reproduced by in vitro site-directed mutagenesis of full-length von Willebrand factor (vWF) cDNA and transiently expressed in COS-7 cells. The corresponding recombinant VWFs for these 2 mutations exhibited the typical aberrant vWF:Ag multimer pattern seen in the plasma of the patients. These 3 mutations demonstrate the importance of other carboxy-terminal cysteines in addition to the reported Cys2010 residue, in the normal dimerization of vWF, and their essential role in the assembly of normal multimeric vWF. (Blood. 2001;98:674-680)