Identity of tumour necrosis factor and the macrophage-secreted factor cachectin

In mammals, several well-defined metabolic changes occur during infection, many of which are attributable to products of the reticuloendothelial system. Among these changes, a hypertriglyceridaemic state is frequently evident, resulting from defective triglyceride clearance, caused by systemic suppression of the enzyme lipoprotein lipase (LPL). We have found previously that macrophages secrete the hormone cachectin, which specifically suppresses LPL activity in cultured adipocytes (3T3-L1 cells). When originally purified from RAW 264.7 (mouse macrophage) cells, cachectin was shown to have a pI of 4.7, a subunit size of relative molecular mass (Mr) 17,000 and to form non-covalent multimers. A receptor for cachectin was identified on non-tumorigenic cultured cells and on normal mouse liver membranes. A new high-yield purification technique has enabled us to determine further details of the structure of mouse cachectin. We now report that a high degree of homology exists between the N-terminal sequence of mouse cachectin and the N-terminal sequence recently determined for human tumour necrosis factor (TNF). Purified cachectin also possesses potent TNF activity in vitro. These findings suggest that the 'cachectin' and 'TNF' activities of murine macrophage conditioned medium are attributable to a single protein, which modulates the metabolic activities of normal as well as neoplastic cells through interaction with specific high-affinity receptors.

Plaque-associated expression of human herpesvirus 6 in multiple sclerosis

Representational difference analysis was used to search for pathogens in multiple sclerosis brains. We detected a 341-nucleotide fragment that was 99.4% identical to the major DNA binding protein gene of human herpesvirus 6 (HHV-6). Examination of 86 brain specimens by PCR demonstrated that HHV-6 was present in > 70% of MS cases and controls and is thus a commensal virus of the human brain. By DNA sequencing, 36/37 viruses from MS cases and controls were typed as HHV-6 variant B group 2. Other herpesviruses, retroviruses, and measles virus were detected infrequently or not at all. HHV-6 expression was examined by immunocytochemistry with monoclonal antibodies against HHV-6 virion protein 101K and DNA binding protein p41. Nuclear staining of oligodendrocytes was observed in MS cases but not in controls, and in MS cases it was observed around plaques more frequently than in uninvolved white matter. MS cases showed prominent cytoplasmic staining of neurons in gray matter adjacent to plaques, although neurons expressing HHV-6 were also found in certain controls. Since destruction of oligodendrocytes is a hallmark of MS, these studies suggest an association of HHV-6 with the etiology or pathogenesis of MS.

Wound hypoxia and acidosis limit neutrophil bacterial killing mechanisms

BACKGROUND

"Respiratory burst" activity, ie, O2- production, is dependent on PO2, temperature, pH, and glucose concentrations within the physiologic range.

OBJECTIVES

To determine whether environmental conditions characteristic of wounds may limit human neutrophil respiratory burst metabolism and to clarify the degree to which bactericidal oxidant production depends on local PO2.

METHODS

Human blood and wound neutrophils were stimulated with phorbol myristate acetate. Oxygen consumption and superoxide production were measured over a range of 30 to 300 mm Hg PO2, 0 to 40 mmol/L glucose, pH 6.0 to 8.0, and 30 degrees C to 37 degrees C. The apparent Michaelis Menten constant for oxidant production with respect to PO2 was calculated.

RESULTS

Oxygen consumption and O2- production were dependent on PO2 throughout the range tested. Half-maximal oxidant production occurred in the range of 45 to 80 mm Hg PO2 and maximal at PO2 higher than 300 mm Hg. These data agree with the highest previous estimates. Oxidant generation was also dependent on pH, temperature, and glucose concentration, but to a lesser extent.

CONCLUSIONS

Leukocyte bacterial killing capacity as measured by oxygen consumption and superoxide production are substantially impaired at the low oxygen tensions often found in wounds. Changes in pH, temperature, and glucose concentration have lesser but nonetheless significant consequences. The data provide a plausible mechanism for the vulnerability of some wounds to infection and for the previous finding that increasing oxygen tension at wound sites enhances bactericidal function. Thus, the data serve as a basis for future studies on prevention of wound infection.

Constituents of red yeast rice, a traditional Chinese food and medicine

Detailed analyses were undertaken of the natural constituents of red yeast rice, a traditional Chinese medicine and food known for centuries to improve blood circulation. Preparation of red yeast rice following ancient methods by fermenting the fungal strain Monascus purpureus Went on moist and sterile rice indicated the presence of a group of metabolites belonging to the monacolin family of polyketides, together with fatty acids, and trace elements. The presence of these compounds may explain in part the cholesterol-lowering ability associated with this traditional Chinese food.

Role of areca nut in betel quid-associated chemical carcinogenesis: current awareness and future perspectives

Betel quid (BQ)-chewing is a popular oral habit with potential links to the occurrence of oral cancer. Many of the literature-based studies reveal that areca nut (AN) extract may demonstrate mutagenic and genotoxic effects, in addition to inducing preneoplastic as well as neoplastic lesions in experimental animals. Areca nut should, thus, be highly suspected as a human carcinogen. Toxicity studies relating to AN-contained polyphenols and tannins are not conclusive, with both carcinogenic and anti-carcinogenic effects being reported. The mutagenicity and genotoxicity of areca alkaloids has been detected by many short-term assays. However, their genotoxicity to oral fibroblasts and keratinocytes, the target cells of BQ, has not been identified. It would thus appear that AN toxicity is not completely due to its polyphenol, tannin and alkaloid content. The single agent which is responsible for AN carcinogenicity awaits further clarification. Reactive oxygen species produced during auto-oxidation of AN polyphenols in the BQ-chewer's saliva, are crucial in the initiation and promotion of oral cancer. Nitrosation of areca alkaloids also produces AN-specific nitrosamines, that have been demonstrated to be mutagenic, genotoxic and are capable of inducing tumors in experimental animals. Arecaidine and AN extract are further suggested to be tumor promoters. Antioxidants such as glutathione and N-acetyl-L-cysteine can potentially prevent such AN-elicited cytotoxicity. Further studies are needed to delineate the metabolism of AN ingredient and their roles in the multi-step chemical carcinogenesis, in order to enhance the success of the future chemoprevention of oral cancer and oral submucous fibrosis.

Diagnosis and initial management of blunt pancreatic trauma: guidelines from a multiinstitutional review

OBJECTIVE

The authors' objective was to resolve the current controversies surrounding the diagnosis and management of blunt pancreatic trauma (BPT).

SUMMARY BACKGROUND DATA

The diagnosis of BPT is notoriously difficult: serum amylase has been claimed to be neither sensitive nor specific, and recent anecdotal reports have suggested a role for computed tomography. The therapy of BPT has been controversial, with some suggesting selective observation and others advocating immediate exploration to prevent a delay-induced escalation in morbidity and death.

METHODS

The authors conducted a retrospective chart review of documented BPT from six institutions, using a standardized binary data form composed of 187 items and 237 data fields.

RESULTS

A significant correlation between pancreas-specific morbidity and injury to the main pancreatic duct (MPD) was noted. Patients requiring delayed surgical intervention after an unsuccessful period of observation demonstrated notably higher pancreas-specific mortality and morbidity rates, principally because of the incidence of unrecognized injuries to the MPD. Although detection of MPD injuries by computed tomography was no better than flipping a coin, endoscopic pancreatography was accurate in each of the five cases in which it was used.

CONCLUSIONS

The principal cause of pancreas-specific morbidity after BPT is injury to the MPD. Parenchymal pancreatic injuries not involving the ductal system rarely result in pancreas-specific morbidity or death. Delay in recognizing MPD injury leads to increased mortality and morbidity rates. CT is unreliable in diagnosing MPD injury and should not be used to guide therapy. Initial selection of patients with isolated BPT for observation or surgery can be based on the determination of MPD integrity.

Implant supported single-tooth replacements compared to contralateral natural teeth. Crown and soft tissue dimensions

The aim of this study was to make a comparative evaluation of crown and soft tissue dimensions between implant-supported single-tooth replacements and the contralateral natural tooth. Twenty patients, who had been treated with an implant-supported single-tooth replacement in the esthetic zone of the maxillary jaw and had i) a non-restored contralateral natural tooth and ii) completed the implant-supported crown restoration at least 6 months prior to the scheduled follow-up examination, were included in the study. At the re-examination various variables describing crown form, soft tissue dimensions and soft tissue conditions were assessed. In addition, the patient's overall satisfaction with the esthetic outcome of the implant-supported single crown was scored using a Visual Analogue Scale (VAS). In 12 of the subjects clinical photographs were available from the time of crown insertion for evaluation of longitudinal alterations of the papilla height. The results revealed that, in comparison to the contralateral natural crown, the implant supported crown i) was longer, ii) had a smaller facio-lingual width, iii) was bordered by a thicker facial mucosa, iv) had a lower height of the distal papilla, v) showed a higher frequency of mucositis and bleeding on probing and vi) showed greater probing depths. The longitudinal evaluation of the papillae adjacent to the implant crown showed an improved proximal soft tissue fill at the follow-up examination. The VAS scoring of the patients' satisfaction with the appearance of their single implant-supported restorations revealed a median value of 96% with a range from 70 to 100%. Hence, observed differences in clinical crown height and soft tissue topography between implant-supported single-tooth replacements and the contralateral natural tooth may in most patients be of minor importance for the appreciation of the esthetic outcome of implant therapy.

Interleukin-6 inhibits transforming growth factor-beta-induced apoptosis through the phosphatidylinositol 3-kinase/Akt and signal transducers and activators of transcription 3 pathways

The multifunctional cytokine interleukin-6 (IL-6) regulates growth and differentiation of many cell types and induces production of acute-phase proteins in hepatocytes. Here we report that IL-6 protects hepatoma cells from apoptosis induced by transforming growth factor-beta (TGF-beta), a well known apoptotic inducer in liver cells. Addition of IL-6 blocked TGF-beta-induced activation of caspase-3 while showing no effect on the induction of plasminogen activator inhibitor-1 and p15(INK4B) genes, indicating that IL-6 interferes with only a subset of TGF-beta activities. To further elucidate the mechanism of this anti-apoptotic effect of IL-6, we investigated which signaling pathway transduced by IL-6 is responsible for this effect. IL-6 stimulation of hepatoma cells induced a rapid tyrosine phosphorylation of the p85 subunit of phosphatidylinositol 3-kinase (PI 3-kinase) and its kinase activity followed by the activation of Akt. Inhibition of PI 3-kinase by wortmannin or LY294002 abolished the protection of IL-6 against TGF-beta-induced apoptosis. A dominant-negative Akt also abrogated this anti-apoptotic effect. Dominant-negative inhibition of STAT3, however, only weakly attenuated the IL-6-induced protection. Finally, inhibition of both STAT3 and PI 3-kinase by treating cells overexpressing the dominant-negative STAT3 with LY294002 completely blocked IL-6-induced survival signal. Thus, concomitant activation of the PI 3-kinase/Akt and the STAT3 pathways mediates the anti-apoptotic effect of IL-6 against TGF-beta, with the former likely playing a major role in this anti-apoptosis.

hSK4/hIK1, a calmodulin-binding KCa channel in human T lymphocytes. Roles in proliferation and volume regulation

Human T lymphocytes express a Ca2+-activated K+ current (IK), whose roles and regulation are poorly understood. We amplified hSK4 cDNA from human T lymphoblasts, and we showed that its biophysical and pharmacological properties when stably expressed in Chinese hamster ovary cells were essentially identical to the native IK current. In activated lymphoblasts, hSK4 mRNA increased 14.6-fold (Kv1.3 mRNA increased 1.3-fold), with functional consequences. Proliferation was inhibited when Kv1.3 and IK were blocked in naive T cells, but IK block alone inhibited re-stimulated lymphoblasts. IK and Kv1.3 were involved in volume regulation, but IK was more important, particularly in lymphoblasts. hSK4 lacks known Ca2+-binding sites; however, we mapped a Ca2+-dependent calmodulin (CaM)-binding site to the proximal C terminus (Ct1) of hSK4. Full-length hSK4 produced a highly negative membrane potential (Vm) in Chinese hamster ovary cells, whereas the channels did not function when either Ct1 or the distal C terminus was deleted (Vm approximately 0 mV). Native IK (but not expressed hSK4) current was inhibited by CaM and CaM kinase antagonists at physiological Vm values, suggesting modulation by an accessory molecule in native cells. Our results provide evidence for increased roles for IK/hSK4 in activated T cell functions; thus hSK4 may be a promising therapeutic target for disorders involving the secondary immune response.

Water is required for proton transfer from aspartate-96 to the bacteriorhodopsin Schiff base

During the M in equilibrium with N----BR reaction sequence in the bacteriorhodopsin photocycle, proton is exchanged between D96 and the Schiff base, and D96 is reprotonated from the cytoplasmic surface. We probed these and the other photocycle reactions with osmotically active solutes and perturbants and found that the M in equilibrium with N reaction is specifically inhibited by withdrawing water from the protein. The N----BR reaction in the wild-type protein and the direct reprotonation of the Schiff base from the cytoplasmic surface in the site-specific mutant D96N are much less affected. Thus, it appears that water is required inside the protein for reactions where a proton is separated from a buried electronegative group, but not for those where the rate-limiting step is the capture of a proton at the protein surface. In the wild type, the largest part of the barrier to Schiff base reprotonation is the enthalpy of separating the proton from D96, which amounts to about 40 kJ/mol. We suggest that in spite of this D96 confers an overall kinetic advantage because when this residue becomes anionic in the N state its electric field near the cytoplasmic surface lowers the free energy barrier of the capture of a proton in the next step. In the D96N protein, the barrier to the M----BR reaction is 20 kJ/mol higher than what would be expected from the rates of the M----N and N----BR partial reactions in the wild type, presumably because this mechanism is not available.

Pathways of proton release in the bacteriorhodopsin photocycle

The pH dependencies of the rate constants in the photocycles of recombinant D96N and D115N/D96N bacteriorhodopsins were determined from time-resolved difference spectra between 70 ns and 420 ms after photoexcitation. The results were consistent with the model suggested earlier for proteins containing D96N substitution: BR hv----K----L----M1----M2----BR. Only the M2----M1 back-reaction was pH-dependent: its rate increased with increasing [H+] between pH 5 and 8. We conclude from quantitative analysis of this pH dependency that its reverse, the M1----M2 reaction, is linked to the release of a proton from a group with a pKa = 5.8. This suggests a model for wild-type bacteriorhodopsin in which at pH greater than 5.8 the transported proton is released on the extracellular side from this as yet unknown group and on the 100-microseconds time scale, but at pH less than 5.8, the proton release occurs from another residue and later in the photocycle most likely directly from D85 during the O----BR reaction. We postulate, on the other hand, that proton uptake on the cytoplasmic side will be by D96 and during the N----O reaction regardless of pH. The proton kinetics as measured with indicator dyes confirmed the unique prediction of this model: at pH greater than 6, proton release preceded proton uptake, but at pH less than 6, the release was delayed until after the uptake. The results indicated further that the overall M1----M2 reaction includes a second kinetic step in addition to proton release; this is probably the earlier postulated extracellular-to-cytoplasmic reorientation switch in the proton pump.

The hyaluronan receptor RHAMM regulates extracellular-regulated kinase

We have identified two RHAMM (receptor for hyaluronan-mediated motility) isoforms that encode an alternatively spliced exon 4 (Hall, C. L., Yang, B., Yang, X., Zhang, S., Turley, M., Samuel, S., Lange, L. A., Wang, C., Curpen, G. D., Savani, R. C., Greenberg, A. H., and Turley, E. A. (1995) Cell 82, 19-26 and Wang, C., Entwistle, J., Hou, G., Li, Q., and Turley, E. A. (1996) Gene 174, 299-306). One of these, RHAMM variant 4 (RHAMMv4), is transforming when overexpressed and regulates Ras signaling (Hall et al.). Here we note using flow cytometry and confocal analysis that RHAMM isoforms encoding exon 4 occur both on the cell surface and in the cytoplasm. Epitope-tagging experiments indicate that RHAMMv4 occurs only in the cytoplasm. Several observations suggest that both cell surface RHAMM isoforms and RHAMMv4 are involved in regulating extracellular-regulated kinase (ERK) activity. Affinity-purified anti-RHAMM exon 4 antibodies block the ability of platelet-derived growth factor to activate ERK, and these reagents modify the protein tyrosine phosphorylation profile of proteins resulting from treatment with platelet-derived growth factor. A dominant negative form of RHAMMv4 inhibits mutant active Ras activation of ERK and coimmunoprecipitates with both mitogen-activated protein kinase kinase and ERK, suggesting that the intracellular RHAMMv4 acts downstream of Ras, possibly at the level of mitogen-activated protein kinase kinase-ERK interactions. Consistent with this, overexpression of RHAMMv4 constitutively activates ERK. These results identify a novel mechanism for the regulation of the Ras-ERK signaling pathway and suggest that RHAMM plays multiple roles in this regulation.

Primary ex vivo cultures of human fallopian tube epithelium as a model for serous ovarian carcinogenesis

Recent studies suggest that some serous ovarian carcinomas (SOCs) arise from the fallopian tube (FT) epithelium rather than the ovarian surface epithelium. This hypothesis places emphasis on the FT secretory epithelial cell as a cell-of-origin. Herein, we report the development of a novel ex vivo primary human FT epithelium culture system that faithfully recapitulates the in vivo epithelium, as shown by morphological, ultrastructural and immunophenotypic analyses. Mass spectrometry-based proteomics reveal that these cultures secrete proteins previously identified as biomarkers for ovarian cancer. We also use this culture system to study the response of the FT epithelium to genotoxic stress and find that the secretory cells exhibit a distinct response to DNA damage when compared with neighboring ciliated cells. The secretory cells show a limited ability to resolve the damage over time, potentially leaving them more susceptible to accumulation of additional mutagenic injury. This divergent response is confirmed with in situ studies using tissue samples, further supporting the use of this ex vivo culture system to investigate FT epithelial pathobiology. We anticipate that this novel culture system will facilitate the study of SOC pathogenesis, and propose that similar culture systems could be developed for other organ site-specific epithelia.

Impact of preexisting and induced humoral and cellular immune responses in an adenovirus-based gene therapy phase I clinical trial for localized mesothelioma

Little is known about the immune responses induced by recombinant adenoviral (Ad) vectors in humans. The humoral and cellular immune responses were therefore analyzed in 21 patients with localized malignancy (mesothelioma), who received intrapleurally high doses of a replication-defective Ad5 vector carrying a suicide gene. Eight of 21 patients had pretreatment titers of neutralizing antibodies (NAb) to Ad at > or =1:100. Peripheral blood mononuclear cells (PBMCs) proliferated in response to adenoviral 5 structural proteins before treatment in 17 of 21 patients. Preexisting humoral and cellular immunity did not preclude gene transfer. Vector instillation induced high titers of nonneutralizing and neutralizing anti-Ad antibody (4- to 341-fold increase in 18 of 20 patients) in a dose-dependent manner. Three patients generated antibodies to the transgene, herpes simplex virus thymidine kinase. Ad5-specific proliferation of PBMCs increased significantly (>3-fold) after vector administration in 12 of 21 patients in a dose-dependent manner. Thus, replication-defective Ad5 administered intrapleurally induced significant humoral and cellular immune responses that induced no obvious adverse clinical sequelae.

A complex containing RNA polymerase II, Paf1p, Cdc73p, Hpr1p, and Ccr4p plays a role in protein kinase C signaling

Yeast contains at least two complex forms of RNA polymerase II (Pol II), one including the Srbps and a second biochemically distinct form defined by the presence of Paf1p and Cdc73p (X. Shi et al., Mol. Cell. Biol. 17:1160-1169, 1997). In this work we demonstrate that Ccr4p and Hpr1p are components of the Paf1p-Cdc73p-Pol II complex. We have found many synthetic genetic interactions between factors within the Paf1p-Cdc73p complex, including the lethality of paf1Delta ccr4Delta, paf1Delta hpr1Delta, ccr4Delta hpr1Delta, and ccr4Delta gal11Delta double mutants. In addition, paf1Delta and ccr4Delta are lethal in combination with srb5Delta, indicating that the factors within and between the two RNA polymerase II complexes have overlapping essential functions. We have used differential display to identify several genes whose expression is affected by mutations in components of the Paf1p-Cdc73p-Pol II complex. Additionally, as previously observed for hpr1Delta, deleting PAF1 or CDC73 leads to elevated recombination between direct repeats. The paf1Delta and ccr4Delta mutations, as well as gal11Delta, demonstrate sensitivity to cell wall-damaging agents, rescue of the temperature-sensitive phenotype by sorbitol, and reduced expression of genes involved in cell wall biosynthesis. This unusual combination of effects on recombination and cell wall integrity has also been observed for mutations in genes in the Pkc1p-Mpk1p kinase cascade. Consistent with a role for this novel form of RNA polymerase II in the Pkc1p-Mpk1p signaling pathway, we find that paf1Delta mpk1Delta and paf1Delta pkc1Delta double mutants do not demonstrate an enhanced phenotype relative to the single mutants. Our observation that the Mpk1p kinase is fully active in a paf1Delta strain indicates that the Paf1p-Cdc73p complex may function downstream of the Pkc1p-Mpk1p cascade to regulate the expression of a subset of yeast genes.

Use of omeprazole as a probe drug for CYP2C19 phenotype in Swedish Caucasians: comparison with S-mephenytoin hydroxylation phenotype and CYP2C19 genotype

A single oral dose of omeprazole (20 mg) was given orally to 160 healthy Caucasian Swedish subjects and tested as a probe for CYP2C19. The study was nonrandomized and included seven subjects previously classified as poor metabolizers (PM) of S-mephenytoin. The ratio between the plasma concentrations of omeprazole and hydroxyomeprazole (metabolic ratio; MR) was determined by HPLC in a blood sample drawn 3 h after drug intake. In 17 subjects the test was repeated and the MRs of omeprazole on the two occasions were correlated (rs = 0.85; p < 0.0001). There was a significant correlation between the MR of omeprazole and the S/R mephenytoin ratio among 141 subjects, in whom both ratios were determined (rs = 0.63, p < 0.001). All seven PMs of S-mephenytoin had higher MRs of omeprazole (7.1-23.8) than extensive metabolizers (EM) (0.1-4.9). All 160 subjects and another 15 Caucasian Swedish PMs previously phenotyped with mephenytoin were analysed with respect to the presence of the CYP2C19m1 allele by PCR amplification of the intron 4/exon 5 junction followed by Sma I digestion. EMs heterozygous for the CYP2C19m1 gene had MRs of omeprazole and S/R ratios of mephenytoin that were higher than those of subjects who were homozygous for the wild-type allele (p = 0.0001). Nineteen of the 22 PMs were homozygous for the CYP2C19m1 gene. Three were heterozygous for this allele. Thus, 41 of the 44 alleles (93%) of PMs were defective CYP2C19m1. One of the remaining three PM alleles was subsequently found to contain the CYP2C19m2 mutation, which has earlier been shown to be associated with the PM phenotype in Oriental populations. In conclusion, the phenotype determined by omeprazole correlated with that of mephenytoin, and was in good agreement with the genotype.

Interphenotype differences in disposition and effect on gastrin levels of omeprazole--suitability of omeprazole as a probe for CYP2C19

1. Fourteen healthy Swedish Caucasian subjects were given 20 mg of omeprazole orally each morning for 8 days. The subjects included five poor metabolisers (PM) of S-mephenytoin, four heterozygous extensive metabolisers (hetEM) and five subjects with a very rapid metabolism (rapidEM). 2. After the first dose, the relative mean areas under the plasma concentration vs time curve (AUC) of omeprazole in rapidEM, hetEM and PM were 1:3.7:20 (all different, P < 0.001). A similar relation was seen in the AUC(0,10 h) of the sulphone metabolite (1:3:12). Concentrations of hydroxyomeprazole were higher in EM than in PM confirming that the hydroxy, but not the sulphone metabolite, is formed by the S-mephenytoin hydroxylase (CYP2C19). After 8 days of treatment, the differences between groups were similar. 3. After both the first and the eighth doses, the omeprazole/hydroxyomeprazole plasma concentration ratio, determined 3 h after drug intake, correlated with the mephenytoin S/R ratio (rs = 0.94; P < 0.001; n = 14) suggesting that omeprazole might be used to phenotype for CYP2C19. 4. After the first dose of omeprazole, there was no difference in the AUC(0,10 h) of plasma gastrin between the three groups. From the first to the eighth dose, the AUC(0,10) of gastrin increased significantly in both hetEM and PM, while there was no change in the rapidEM. After the eighth dose, the AUC(0,10) of gastrin correlated significantly with the AUC of omeprazole in plasma (rs = 0.79; P < 0.01; n = 13).

Histone H2B repression causes cell-cycle-specific arrest in yeast: effects on chromosomal segregation, replication, and transcription

To determine which cellular processes are dependent on histones, we blocked histone H2B mRNA synthesis in asynchronously growing yeast after fusing the H2B gene to a repressible GAL10 promoter. Chromosomal segregation, replication, and transcription were then examined. We found that the cells arrested in mitosis, with a cell division cycle (cdc) phenotype. Chromatin structure and nuclear segregation were disrupted. A full round of DNA replication took place after the repression of histone H2B mRNA synthesis. Active transcription and the induction of new transcripts also continued in the arrested cells.

Endopyelotomy and endoureterotomy with the acucise ureteral cutting balloon device: preliminary experience

Endoureterotomy and endopyelotomy usually involve an endoscopic antegrade approach. In an effort to simplify this technique, we designed an 8-mm balloon catheter with a 100-microns electrocautery cutting wire (Acucise) for retrograde incision of the ureter under fluoroscopic control. Twenty-eight patients with ureteral or ureteropelvic junction obstruction of 3.5 cm or less underwent Acucise endoureterotomy or endopyelotomy. The average operating time was 100 minutes, and the average hospital stay was 2.6 days. Follow-up was obtained with a subjective symptom score, intravenous urography, diuretic renal scan, a Whitaker test, or various combinations thereof. All patients had a minimum of 3 months of follow-up (mean 3.8 months; range 3-9 months). Overall, of the 21 patients who had symptoms of upper tract urinary obstruction, 14 (67%) had complete resolution, and another 4 (19%) had partial resolution, of their symptoms. Postoperative studies demonstrated normal upper tracts in 71% and improvement in another 14% of the patients. In our experience, the Acucise ureteral cutting balloon device provides an effective and efficient means for performing a retrograde endoureterotomy or endopyelotomy.

The anti-apoptotic role of interleukin-6 in human cervical cancer is mediated by up-regulation of Mcl-1 through a PI 3-K/Akt pathway

Interleukin-6 (IL-6), a multifunctional cytokine, has recently been implicated in human cervical cancer, though the mechanism remains elusive. This study demonstrates that the anti-apoptotic protein Mcl-1 and IL-6 was concomitantly expressed in human cervical cancer tissues and cell lines, but not in normal cervix tissues. Upon IL-6 treatment, Mcl-1, but not other Bcl-2 family members, was rapidly up-regulated peaking at 4-8 h in human cervical cancer C33A cells. Supporting this observation, using anti-IL-6 or anti-IL-6 receptor antibody to interrupt the IL-6 autocrine loop in SiHa cells significantly reduced cellular level of Mcl-1. This study hypothesizes that the expression of Mcl-1 in cervical cancer cells is regulated by IL-6. The matter of which signaling pathways transduced by IL-6 is responsible for the Mcl-1 up-regulation is further investigated herein. Blocking the STAT3 or MAPK pathway with dominant-negative mutant STAT3F or the MEK inhibitor PD98059 failed to inhibit IL-6-mediated Mcl-1 expression. Meanwhile, the IL-6-induced Mcl-1 up-regulation was effectively abolished by treatment with PI 3-K inhibitors, LY294002. Additionally, overexpression of dominant-negative (dn) Akt in C33A cells could inhibit the IL-6-induced increase of Mcl-1. Finally, overexpression of IL-6 in C33A cells caused a markable resistance to apoptosis induced by doxorubicin or cisplatin. Transient transfection of IL-6-overexpressed cells with a mcl-1 antisense vector, leading to the attenuation of their apoptosis-resistant activity. In conclusion, the data herein suggest that IL-6 regulated the mcl-1 expression via a PI 3-K/Akt-dependent pathway that may facilitate the oncogenesis of human cervical cancer by modulating the apoptosis threshold.

Estimation of intra-abdominal pressure by bladder pressure measurement: validity and methodology

BACKGROUND

Increased intra-abdominal pressure (IAP) is an adverse complication seen in critically ill, injured, and postoperative patients. IAP is estimated via the measurement of bladder pressure. Few studies have been performed to establish the actual relationship between IAP and bladder pressure. The purpose of this study was to confirm the association between intravesicular pressure and IAP and to determine the bladder volume that best approximates IAP.

METHODS

Thirty-seven patients undergoing laparoscopy had intravesicular pressures measured with bladder volumes of 0, 50, 100, 150, and 200 mL at directly measured intra-abdominal pressures of 0, 5, 10, 15, 20, and 25 mm Hg. Correlation coefficients and differences were then determined.

RESULTS

Across the IAP range of 0 to 25 mm Hg using all of the tested bladder volumes, the difference between IAP and intravesicular pressures (bias) was -3.8 +/- 0.29 mm Hg (95% confidence interval) and measurements were well correlated (R2 = 0.68). Assessing all IAPs tested, a bladder volume of 0 mL demonstrated the lowest bias (-0.79 +/- 0.73 mm Hg). When considering only elevated IAPs (25 mm Hg), a bladder volume of 50 mL revealed the lowest bias (-1.5 +/- 1.36 mm Hg). A bladder volume of 50 mL in patients with elevated IAP resulted in an intravesicular pressure 1 to 3 mm Hg higher than IAP (95% confidence interval).

CONCLUSION

Intravesicular pressure closely approximates IAP. Instillation of 50 mL of liquid into the bladder improves the accuracy of the intravesicular pressure in measuring elevated IAPs.

Debrancher deficiency: neuromuscular disorder in 5 adults

Five patients, 4 men and 1 woman, had adult-onset and slowly progressive weakness. There was distal wasting in 2, hepatomegaly in 3, and congestive heart failure in 2. Electromyography showed a mixed pattern with abundant fibrillations. Serum creatine phosphokinase was increased 5- to 45-fold. Blood glucose failed to respond to epinephrine or glucagon, and venous lactate did not rise after ischemic exercise. Muscle biopsy showed vacuolar myopathy affecting both fiber types. By electron microscopy the vacuoles corresponded to large pools of glycogen not limited by a membrane. Glycogen concentration was 3 to 5 times normal in muscle and 7 to 21 times normal in erythrocytes. In the presence of iodine, muscle glycogen showed a spectrum characteristic of phosphorylase-limit-dextrin. Debrancher activity was measured by a spectrophotometric assay and by a radioactive reverse reaction. The activity was lacking in muscle and erythrocytes of 4 patients according to both assays; in 1 patient the reverse reaction was not impaired. Though previously reported in only 5 patients, debrancher deficiency myopathy may not be rare and should be considered in the differential diagnosis of adult-onset hereditary myopathies.

Cdc73p and Paf1p are found in a novel RNA polymerase II-containing complex distinct from the Srbp-containing holoenzyme

The products of the yeast CDC73 and PAF1 genes were originally identified as RNA polymerase II-associated proteins. Paf1p is a nuclear protein important for cell growth and transcriptional regulation of a subset of yeast genes. In this study we demonstrate that the product of CDC73 is a nuclear protein that interacts directly with purified RNA polymerase II in vitro. Deletion of CDC73 confers a temperature-sensitive phenotype. Combination of the cdc73 mutation with the more severe paf1 mutation does not result in an enhanced phenotype, indicating that the two proteins may function in the same cellular processes. To determine the relationship between Cdc73p and Paf1p and the recently described holoenzyme form of RNA polymerase II, we created yeast strains containing glutathione S-transferase (GST)-tagged forms of CDC73, PAF1, and TFG2 functionally replacing the chromosomal copies of the genes. Isolation of GST-tagged Cdc73p and Paf1p complexes has revealed a unique form of RNA polymerase II that contains both Cdc73p and Paf1p but lacks the Srbps found in the holoenzyme. The Cdc73p-Paf1p-RNA polymerase II-containing complex also includes Gal11p, and the general initiation factors TFIIB and TFIIF, but lacks TBP, TFIIH, and transcription elongation factor TFIIS as well as the Srbps. The Srbp-containing holoenzyme does not include either Paf1p or Cdc73p, demonstrating that these two forms of RNA polymerase II are distinct. In confirmation of the hypothesis that the two forms coexist in yeast cells, we found that a TFIIF-containing complex isolated via the GST-tagged Tfg2p construct contains both (i) the Srbps and (ii) Cdc73p and Paf1p. The Srbps and Cdc73p-Paf1p therefore appear to define two complexes with partially redundant, essential functions in the yeast cell. Using the technique of differential display, we have identified several genes whose transcripts require Cdc73p and/or Paf1p for normal levels of expression. Our analysis suggests that there are multiple RNA polymerase II-containing complexes involved in the expression of different classes of protein-coding genes.