Analysis of gene expression identifies PLAB as a mediator of the apoptotic activity of fenretinide in human ovarian cancer cells.

Fenretinide (4-HPR) is a synthetic retinoid with antitumor activity, which induces apoptosis in cancer cell lines of different histotypes. To identify genes contributing to its apoptotic activity in ovarian cancer cells, we monitored, by cDNA arrays, gene expression changes after 4-HPR exposure in A2780, a human ovarian carcinoma cell line sensitive to the retinoid. Among the differentially expressed transcripts, PLAcental Bone morphogenetic protein (PLAB), a proapoptotic gene, was the most highly induced. In a panel of ovarian carcinoma cell lines with different 4-HPR sensitivities, PLAB upregulation was associated with cellular response to 4-HPR, its overexpression increased basal apoptosis and its silencing by small interfering RNA decreased the ability of 4-HPR to induce apoptosis. PLAB induction by 4-HPR was p53- and EGR-1 independent and was regulated, at least in part, by increased stability of PLAB mRNA. PLAB up-modulation by 4-HPR also occurred in vivo: in ascitic cells collected from patients with ovarian cancer before and after 4-HPR treatment, PLAB was upmodulated in 2/4 patients. Our results in certain ovarian cancer cell lines indicate a role for PLAB as a mediator of 4-HPR-induced apoptosis. The correlation of increased PLAB in vivo with antitumor activity remains to be established.

The JAK2 V617F mutation and thrombosis.

Since the discovery of the JAK2 V617F mutation, the clinical and pathological consequences of this acquired defect have been extensively investigated to determine whether its presence characterises a distinct subgroup of myeloproliferative disorders (MPD). MPD management remains highly dependent on the patient's thrombotic risk. Whether the presence of the JAK2 V617F mutation modifies the thrombotic risk is currently contentious, although there is increasing clinical evidence to suggest that the mutation may be variably associated with thrombosis. These observations are further supported by laboratory parameters which suggest that the JAK2 V617F mutation may confer increased activation of leucocytes and platelets in MPD. The role of screening for the JAK2 V617F mutation in patients presenting with thrombosis without overt MPD is unclear, but appears justified in cases of idiopathic splanchnic vein thrombosis.

Audit of the peri-delivery use of unfractionated heparin in women on therapeutic low-molecular weight heparin.

There is no evidence-based approach for the optimal management of peri-delivery anticoagulation in women receiving therapeutic dose of low-molecular weight heparin (LMWH) during pregnancy. Nevertheless, the maintenance of anticoagulation for the maximal period peri-delivery appears appropriate in women considered to be at high risk of venous or arterial thromboembolism. We developed a regimen based on fixed thromboprophylactic dose of unfractionated heparin (UFH) peri-delivery and undertook an audit to evaluate the use and feasibility of this approach and any adverse events. Fixed intravenous thromboprophylactic dose of UFH (15,000 units/24 h) was commenced on the evening prior to a planned delivery [induction of labour or elective caesarean section (CS)], stopped 4 h predelivery and restarted 2-6 h postdelivery. Compliance was good with 32/38 consecutive deliveries managed according to the regimen. There were no cases of postpartum haemorrhage and no thrombosis associated with these 32 deliveries. Twenty-one patients were delivered by CS (11 elective) and eight patients received epidural/spinal anaesthesia without complication. In conclusion, the fixed thromboprophylactic dose UFH regimen provided maintenance of anticoagulation except for a matter of hours without excessive bleeding risk (conducive to neuroaxial anaesthesia) and was simple, flexible and acceptable to staff and patients.

Loss of the oncogenic phosphatase PRL-3 promotes a TNF-R1 feedback loop that mediates triple-negative breast cancer growth.

Stimulating tumor cell senescence and apoptosis are proven methods for therapeutically combating cancer. However, senescence and apoptosis are conventionally viewed as parallel, not sequential, processes. We have discovered that the metastasis-promoting phosphatase, PRL-3, is transcriptionally regulated by the NF-ĸB pathway in triple-negative breast cancer (TNBC) cells, and that PRL-3 knockdown elicits an autocrine tumor necrosis factor receptor 1 (TNF-R1) feedback loop that results in TNBC cell senescence followed by apoptosis. Knockdown of PRL-3 leads to rapid G1 cell cycle arrest and induction of a strong TNFα cytokine response that promotes a period of cellular senescence through TNF-R1-mediated activation of NF-ĸB. Senescent PRL-3 knockdown cells subsequently underwent apoptosis as a result of increased TNF-R1 signaling through the TNFα-associated extrinsic death pathway, shunting signaling away from the NF-ĸB cascade. These data suggest that TNF-R1 signaling dynamically re-programs after PRL-3 knockdown, from sustaining cell senescence through NF-ĸB to promoting apoptosis through TNF-R1 internalization and caspase-8 activation. The molecular mechanisms that determine the survival-death balance of TNF-R1 signaling are poorly understood, despite the fact that TNF-R1 has been extensively studied. Our results describe PRL-3 knockdown as a novel survival-death balance modifier of the TNF-R1 pathway, and show that senescent TNBC tumor cells can be sensitized to undergo apoptosis in a sequential manner.

L-thyroxine absorption in patients with short bowel.

Because the exact site of thyroid hormone absorption in man is not known, we assessed the absorption of oral [125I]Na-L-T4 in patients with varying lengths of intact bowel and correlated this absorption with bowel length. Two normal subjects and five patients with surgical bowel resections, all of whom were euthyroid, were studied. Each received a tracer dose of [125I]Na-L-T4 orally, and serial samples of serum were assayed for radioactivity both with and without butanol extraction. The peak serum radioactivity in normal subjects occurred 2 h post ingestion and was 15% and 17% of the administered dose per liter serum and 11% and 13%/liter serum in butanol-extracted serum, respectively. In patients with shortened bowel, the peak radioactivity both in serum and butanol extracted serum was decreased, ranging from 2%-7% and 0%-5%/liter, respectively. There was no absorption of labeled T4 in the patient with a duodenum only. No consistent relationship was found between absorption and bowel length distal to the duodenum.

Changes in serum carotenoids in subjects with colorectal adenomas after 24 mo of beta-carotene supplementation. Australian Polyp Prevention Project Investigators.

The effect of beta-carotene supplementation on major serum carotenoid fractions (lutein/zeaxanthin, beta-cryptoxanthin, lycopene, alpha-carotene, and beta-carotene) was investigated in 224 people with colorectal adenomas (139 men, 85 women) recruited for the Australian Polyp Prevention Project (APPP). Each subject was randomly assigned to take either 20 mg beta-carotene/d or placebo over 24 mo. Besides the expected increase in serum concentration of beta-carotene (1073% in men, 839% in women), lycopene (176% in men) and alpha-carotene (211% in men and 166% in women) concentrations were also increased after body mass index, baseline concentration, change in respective carotenoid intake, and other confounding factors were adjusted for. The increase in serum concentrations of these carotenoids after beta-carotene supplementation suggests that beta-carotene may interact biologically with other carotenoids and such interaction would need to be taken into consideration when the protective effect of beta-carotene supplementation for cancer or other diseases is examined.

Tricho-rhino-phalangeal syndrome type I (TRP I) due to an apparently balanced translocation involving 8q24.

Tricho-rhino-phalangeal (TRP) syndromes type I and II are caused by a defective gene located on chromosome 8q24.1. We report a family with 2 sibs affected with TRP type I in combination with an apparently balanced chromosome (8;18) translocation involving 8q24.11. It is very likely that the 8q24 translocation breakpoint is physically linked to the TRP gene(s), thereby facilitating future efforts to clone the TRP gene(s).

The actions of bismuth in the treatment of Helicobacter pylori infection.

Bismuth salts have been used in medicine for over three centuries, particularly in the treatment of dyspepsia. Commonly used agents include colloidal bismuth subcitrate (CBS), bismuth subsalicylate (BSS) and the newer ranitidine bismuth citrate (RBC). These are safe drugs which exert local effects on the gastroduodenal mucosa. Gastric mucosal levels of bismuth exceed the concentrations required to kill Helicobacter pylori in vitro. The mechanisms of actions of bismuth on gastrointestinal pathogens including H. pylori are complex and include inhibition of protein and cell wall synthesis, membrane function and ATP synthesis. Adherence of H. pylori to surface epithelial cells is also impaired. Bismuth monotherapy is effective in vivo to suppress H. pylori but cure rates are low. CBS, BSS and RBC have synergistic activity with one or two antibiotics and are effective in eradicating H. pylori. CBS and RBC also exert other effects on the mucosa including cytoprotective and ulcer healing properties. In addition, RBC is effective in inhibiting gastric acid secretion.

In-vivo anti-reflux and raft properties of alginates.

The comparative efficacy of two alginate-containing anti-reflux preparations (Gaviscon, Algicon) was assessed in a single blind crossover study of 20 patients with gastro-oesophageal reflux disease. The clinical efficacy study was preceded by two studies in healthy volunteers to assess the intragastric effects of Algicon and Gaviscon by pH measurement, endoscopic visualization and gamma scintigraphy. Algicon and Gaviscon were shown to form a raft in the fasting and fed human stomach, with Algicon alone having a potent antacid effect below and within the raft. Both Algicon and Gaviscon liquids significantly reduced the frequency and severity of reflux symptoms from baseline when given at their recommended doses (10 ml and 20 ml four times daily, respectively). There were no significant differences between Algicon and Gaviscon, although 12 patients preferred Algicon (vs 5 for Gaviscon) for control of reflux symptoms. It was concluded that both Algicon and Gaviscon were effective for the symptomatic control of gastro-oesophageal reflux disease.

An evaluation of whole blood testing for Helicobacter pylori in general practice.

BACKGROUND: Rapid whole blood tests for Helicobacter pylori infection were developed to assist in the management of patients with dyspepsia in general practice. However, they have not been extensively tested in this setting. AIM: To investigate the test characteristics of the BM-Test (Helisal Quick Test) when used in general practice. METHOD: One hundred and ten dyspeptic patients attending local general practitioners were recruited into the study. The BM-Test was administered by the general practitioner at the screening visit according to standard instructions supplied with the test kit. The patient was then referred to Nepean or Mornington Peninsula Hospitals for further assessment. including a 14C-urea breath test. The test kit was forwarded to the appropriate hospital centre for an independent, blinded reading. The sensitivity and specificity of the BM-Test were evaluated against the results of the 14C-UBT. RESULTS: Based on general practitioner readings, the BM-Test had a sensitivity of 59.3% and a specificity of 90.2%. The positive and negative predictive values were 87.5% and 65.7%, respectively. When based on independent readings, sensitivity rose to 71.2% and specificity fell to 88.2%. The BM-Test was more sensitive for older patients than for younger patients when based on both the general practitioner and independent readings. CONCLUSION: The BM-Test performs below the generally recommended sensitivity and specificity of 90% required for clinical practice.

A practical single sample dry latex agglutination test for Helicobacter pylori antibody detection.

Assessment of a single serum sample for Helicobacter pylori antibodies is frequently requested in routine diagnostic laboratories. Current enzyme linked immunosorbent assay (ELISA) kits are not ideal for testing small numbers of serum samples and some have low sensitivities, specificities or large grey zones. A panel of 90 serum samples from patients who had presented for routine upper endoscopy was used to compare three kits for the detection of H pylori antibodies: (1) Pyloriset Dry, total antibody latex agglutination, Orion Diagnostica, Espoo, Finland; (2) Pyloriset enzyme immunoassay (EIA), IgG ELISA, Orion; and (3) Hel-p, IgG ELISA, Amrad, Kew, Victoria, Australia. Diagnosis of H pylori positivity was made if culture results and either rapid urease test or histopathology were positive. The sensitivity, specificity, positive, and negative predictive value for each test was as follows: Orion: latex 93.3%, 95.6%, 95.5%, 93.3%, respectively; Orion: EIA-G 84.4%, 97.8%, 97.4%, 84.4%, respectively; and Amrad: EIA-G 100%, 88.9%, 90%, 100%, respectively. The latex test performed better than the EIAs with respect to sensitivity and specificity.

Validation of a modified Kirby-Bauer disk diffusion method for metronidazole susceptibility testing of Helicobacter pylori.

Triple antimicrobial therapy that includes metronidazole has been recommended as a first-line therapy for Helicobacter pylori because it has the highest eradication rates. However, resistance in H. pylori to metronidazole has been reported worldwide and its presence may reduce the efficacy of triple therapy. Various methods for testing H. pylori against metronidazole have been used including agar dilution, disk diffusion and the Etest but there has been little standardization of methods. One hundred isolates of H. pylori from different patients were tested for susceptibility to metronidazole by agar dilution, Etest and disk diffusion (5 micrograms disk). The agar dilution results confirmed the MIC susceptibility breakpoint to be < or = 8 micrograms/ml. Using this breakpoint there was close agreement (98%) between Etest and agar dilution results. For susceptible strains, MICs by E-test were generally one twofold dilution lower. Using the error-rate bounded method, agreement between disk diffusion zone diameter and MIC was 98% for agar dilution with breakpoints of > or = 12 mm and < or = 8 micrograms/ml and 100% for Etest with breakpoints of > or = 12 mm and < or = 8 micrograms/ml. The Etest discriminated better than agar dilution between susceptible and resistant strains and was simple to perform. The disk diffusion test is a reliable and cheaper alternative to the Etest with susceptibility being a zone diameter > or = 12 mm with a 5 micrograms disk. The prevalence of metronidazole resistance in this study was 40% by Etest.

Novel bismuth compounds have in vitro activity against Helicobacter pylori.

The increasing antimicrobial resistance in Helicobacter pylori has led to the search for new therapeutic agents. In this in vitro study, novel compounds combining bismuth with sialic acid inhibitors were investigated for bactericidal activity using time-kill methodology. The activity of these compounds was compared to bismuth subcitrate against a type strain and a clinical isolate of H. pylori. The compounds tested showed cidal activity which was related to the bismuth component of each drug. These compounds may offer a potential advantage over current bismuth preparations with the sialic acid inhibitor moiety interfering with adhesion of H. pylori to gastric epithelium.

Antimicrobial resistance testing of Helicobacter pylori: a comparison of Etest and disk diffusion methods.

Routine antimicrobial resistance testing of Helicobacter pylori is more commonly performed since the correlation between metronidazole resistance and failure to eradicate using this drug, has been made. While resistance testing of H. pylori by Etest is simple to perform, it is expensive compared to disk diffusion methods. In this study the Etest was compared with a modified Kirby-Bauer disk diffusion (NCCLS) method for routine resistance screening of H. pylori. Fifty one pre-treatment isolates were tested against amoxycillin, metronidazole, tetracycline and erythromycin by both Etest and disk diffusion using NCCLS guideline strength disks. Clarithromycin was tested by Etest only. Nitroimidazole and macrolide resistance were detected using the modified Kirby-Bauer disk diffusion method which correlated with Etest minimum inhibitory concentration (MIC). Resistance rates were 49% for metronidazole and 8% for clarithromycin. Cross resistance occurs with macrolides against H. pylori and allows testing of erythromycin to predict resistance to clarithromycin. The very low MICs obtained with H. pylori against amoxycillin and tetracycline require the use of Etest or lower strength disk methods to be used.

Metronidazole prevention of serum liver enzyme abnormalities during total parenteral nutrition.

Abnormal serum liver enzymes are common in adults receiving total parenteral nutrition (TPN). The mechanism(s) responsible for these changes is unclear. One hypothesis is that there is overgrowth of intestinal anaerobic bacteria with subsequent toxic effects on the liver from endotoxins and/or bile acids. A retrospective survey of patients receiving TPN was undertaken. The patients were divided into two matched groups. One group had received metronidazole, a drug that suppresses anaerobic bacteria, while the other group had not. The administration of metronidazole during TPN was associated with prevention of the expected rise of serum alkaline phosphatase, gamma glutamyl transpeptidase, and aspartate amino-transferase. This study supports the concept that anerobic intestinal bacteria may be involved in the pathogenesis of liver changes commonly observed during TPN.

Brown bowel syndrome in Crohn's disease.

We describe a patient with bowel lipofuscinosis developing subsequent to Crohn's disease of five-years' duration. Lipofuscin pigment was demonstrated in the perinuclear region of smooth muscle cells with the longitudinal and circular coats of the ileal muscularis propria but not in the muscularis mucosa. Electron microscopy showed lipofuscin pigment forming within degenerating mitochondria, confirming the "brown bowel" syndrome as a smooth muscle mitochondrial myopathy.

Campylobacter jejuni enterocolitis. A clinicopathologic study.

Sixteen patients with diarrhea due to Campylobacter jejuni seen within a one-year period at a general hospital were studied to review the clinical and pathological features of this illness. Campylobacter jejuni causes an acute diarrheal illness often associated with fever, delayed-onset hematochezia, and severe abdominal pain. Roentgenographically, one may see colonic and ileal ulceration. Sigmoidoscopically, the rectal appearance is similar to that from acute idiopathic ulcerative colitis, while rectal biopsy specimens show preservation of glandular architecture and a range of focal inflammatory changes. These changes are most severe in patients with a history of frank blood in stool, provided the specimens are taken within the first week of illness. No correlation between stool frequency, abdominal pain, or fever and the severity of proctitis in rectal biopsy specimens can be drawn, which suggests that the pathogenic determinants for thesse clinical manifestations may not be in the rectum, but higher in the colon or in the small intestine.

A controlled comparison of tiaprofenic acid and ibuprofen in osteoarthritis.

A multicentre double-blind crossover study of tiaprofenic acid (600 mg daily) against ibuprofen (1.2 g daily) was undertaken in 77 patients with osteoarthritis to compare their efficacy and tolerance. No difference was found between the two agents, both giving pain relief and being safe and acceptable to the majority of patients. It is concluded that in this short-term study, both agents offer effective and safe treatment for osteoarthritis.

The prevalence of Helicobacter pylori in practising dental staff and dental students.

Recent studies suggest Helicobacter pylori is spread by faecal-oral or oral-oral transmission. Gastroenterologists who are exposed to gastric secretions and saliva have a high prevalence of H. pylori infection. Venous blood was obtained from 92 dentists, 40 dental nurses, 33 fifth year and 30 first year dental students. An ELISA assay was used to detect H. pylori IgG antibodies. Results were compared with an age and sex matched normal population. The prevalence of H. pylori infection in dentists, dental nurses, fifth year dental students and first year dental students were 23 per cent, 18 per cent, 18 per cent and 16 per cent, respectively. There were no significant differences when compared with the normal population controls. The prevalence of H. pylori antibody was not significantly increased with years of practice or patient contact time in dentists and dental nurses. Helicobacter pylori infection is uncommon in dental professionals working in the oral cavity.

Clinical indications and efficacy of colloidal bismuth subcitrate.

Colloidal bismuth subcitrate (CBS; DeNol) has been studied in clinical trials investigating the treatment of duodenal and gastric ulcer, non-ulcer dyspepsia, duodenitis, non-steroidal anti-inflammatory drug (NSAID)-induced disease, and Helicobacter pylori-induced gastroduodenitis. Healing rates for duodenal ulcer with CBS are significantly better than with placebo and are similar to results obtained with cimetidine or ranitidine. CBS is significantly better in the treatment of duodenal ulcer resistant to standard doses of H2 antagonists than increased doses of H2 antagonists. Duodenal ulcer relapse at 12 months after initial healing with CBS is significantly less than with H2-antagonist therapy. Ulcer healing with CBS is not influenced by smoking. H. pylori eradication with CBS appears to have little effect in ulcer healing but is of major importance in preventing ulcer relapse. CBS is effective in combination with antibiotics in eradicating H. pylori-associated gastritis. In gastric ulcer disease CBS therapy resulted in significant healing advantages over placebo and was comparable to treatment with cimetidine and sucralfate. CBS has been shown to be effective in the treatment of erosive duodenitis. The role of CBS in treatment of non-ulcer dyspepsia and NSAID-induced damage awaits further clinical studies.