Large-scale genomic analyses with machine learning uncover predictive patterns associated with fungal phytopathogenic lifestyles and traits

Invasive plant pathogenic fungi have a global impact, with devastating economic and environmental effects on crops and forests. Biosurveillance, a critical component of threat mitigation, requires risk prediction based on fungal lifestyles and traits. Recent studies have revealed distinct genomic patterns associated with specific groups of plant pathogenic fungi. We sought to establish whether these phytopathogenic genomic patterns hold across diverse taxonomic and ecological groups from the Ascomycota and Basidiomycota, and furthermore, if those patterns can be used in a predictive capacity for biosurveillance. Using a supervised machine learning approach that integrates phylogenetic and genomic data, we analyzed 387 fungal genomes to test a proof-of-concept for the use of genomic signatures in predicting fungal phytopathogenic lifestyles and traits during biosurveillance activities. Our machine learning feature sets were derived from genome annotation data of carbohydrate-active enzymes (CAZymes), peptidases, secondary metabolite clusters (SMCs), transporters, and transcription factors. We found that machine learning could successfully predict fungal lifestyles and traits across taxonomic groups, with the best predictive performance coming from feature sets comprising CAZyme, peptidase, and SMC data. While phylogeny was an important component in most predictions, the inclusion of genomic data improved prediction performance for every lifestyle and trait tested. Plant pathogenicity was one of the best-predicted traits, showing the promise of predictive genomics for biosurveillance applications. Furthermore, our machine learning approach revealed expansions in the number of genes from specific CAZyme and peptidase families in the genomes of plant pathogens compared to non-phytopathogenic genomes (saprotrophs, endo- and ectomycorrhizal fungi). Such genomic feature profiles give insight into the evolution of fungal phytopathogenicity and could be useful to predict the risks of unknown fungi in future biosurveillance activities.

An Efficient Palladium-Catalyzed α-Arylation of Acetone Below its Boiling Point

The monoarylation of acetone is a powerful transformation, but is typically performed at temperatures significantly in excess of its boiling point. Conditions described for performing the reaction at ambient temperatures led to significant dehalogenation when applied to a complex aryl halide. We describe our attempts to overcome both issues in the context of our drug-discovery program.

Abstract P4-09-06: miR-187 is an independent prognostic factor in lymph node-positive breast cancer patients

Purpose: MicroRNAs (miRNAs) involved in cancer progression have now become the focus of much attention as they represent a new class of biomarkers and potential drug targets. Here, we describe an integrated bioinformatics, functional analysis and translational pathology approach for the identification of novel miRNAs involved in breast cancer progression.

Experimental Design

Differential gene expression can, in part, be attributed to the activity of specific miRNAs. Given a database of miRNA binding site motifs and gene expression levels determined by transcriptomic profiling, correspondence analysis, between group analysis and co-inertia analysis can be combined to produce a ranked list of miRNAs associated with a specific gene signature and phenotype. Here, using two independent breast cancer cohorts, this approach was employed to produce a ranked list of miRNAs associated with disease progression. Functional studies were subsequently carried out in MCF7 cells assessing for alterations in growth, tumorigenicity and agressiveness and miRNA expression was evaluated in two cohorts of breast cancer patients by locked nucleic acid in situ hybridisation on tissue microarrays.

Results: CIA identified miR-187 as a key miRNA associated with poor outcome in breast cancer.

Ectopic expression of miR-187 in MCF7 cells resulted in a more aggressive phenotype (evidenced by increased anchorage-independent growth, migratory and invasive potential).

In a test cohort (n = 117) breast cancer patients, high expression of miR-187 was associated with a trend towards reduced breast cancer-specific survival (BCSS) (p = 0.058), and a significant association with reduced BCSS in lymph node-positive patients (p = 0.036). In a validation cohort (n = 470), high miR-187 was significantly associated with reduced BCSS in the entire cohort (p = 0.021) and, again, in lymph node-positive patients (p = 0.012).

Multivariate cox regression analysis revealed that miR-187 is an independent prognostic factor in both TMA cohorts (Cohort 1 HR-7.369 (95% CI 2.048–26.509, p = 0.002); Cohort 2 HR-2.798 (95% CI 1.518–5.157, p = 0.001).

Conclusions: miR-187 expression in breast cancer leads to the formation of a more aggressive, invasive phenotype and acts as an independent predictor of outcome.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-09-06.

The cocaine- and amphetamine-regulated transcript mediates ligand-independent activation of ERα, and is an independent prognostic factor in node-negative breast cancer

Personalized medicine requires the identification of unambiguous prognostic and predictive biomarkers to inform therapeutic decisions. Within this context, the management of lymph node-negative breast cancer is the subject of much debate with particular emphasis on the requirement for adjuvant chemotherapy. The identification of prognostic and predictive biomarkers in this group of patients is crucial. Here, we demonstrate by tissue microarray and automated image analysis that the cocaine- and amphetamine-regulated transcript (CART) is expressed in primary and metastatic breast cancer and is an independent poor prognostic factor in estrogen receptor (ER)-positive, lymph node-negative tumors in two separate breast cancer cohorts (n=690; P=0.002, 0.013). We also show that CART increases the transcriptional activity of ERα in a ligand-independent manner via the mitogen-activated protein kinase pathway and that CART stimulates an autocrine/paracrine loop within tumor cells to amplify the CART signal. Additionally, we demonstrate that CART expression in ER-positive breast cancer cell lines protects against tamoxifen-mediated cell death and that high CART expression predicts disease outcome in tamoxifen-treated patients in vivo in three independent breast cancer cohorts. We believe that CART profiling will help facilitate stratification of lymph node-negative breast cancer patients into high- and low-risk categories and allow for the personalization of therapy.

Preclinical Pharmacology of FMPD [6-Fluoro-10-[3-(2-methoxyethyl)-4-methyl-piperazin-1-yl]-2-methyl-4H-3-thia-4,9-diaza-benzo[f]azulene]: A Potential Novel Antipsychotic with Lower Histamine H1 Receptor Affinity Than Olanzapine

FMPD [6-fluoro-10-[3-(2-methoxyethyl)-4-methyl-piperazin-1-yl]-2-methyl-4H-3-thia-4,9-diaza-benzo[f]azulene] is a potential novel antipsychotic with high affinity for dopamine D2 (Ki= 6.3 nM), 5-HT(2A) (Ki= 7.3 nM), and 5-HT6 (Ki= 8.0 nM) human recombinant receptors and lower affinity for histamine H1 (Ki= 30 nM) and 5-HT2C (Ki= 102 nM) human recombinant receptors than olanzapine. Oral administration of FMPD increased rat nucleus accumbens 3,4-dihyroxyphenylacetic acid concentrations (ED200 = 6 mg/kg), blocked 5-HT2A agonist-induced increases in rat serum corticosterone levels (ED50= 1.8 mg/kg), and inhibited the ex vivo binding of [125I]SB-258585 [4-iodo-N-[4-methoxy-3-(4-methyl-piperazin-1-yl)-phenyl]-benzenesulfonamide] to striatal 5-HT6 receptors (ED50= 10 mg/kg) but failed to inhibit ex vivo binding of [3H]pyrilamine to hypothalamic histamine H1 receptors at doses of up to 30 mg/kg. In electrophysiology studies, acute administration of FMPD selectively elevated the number of spontaneously active A10 (versus A9) dopamine neurons and chronic administration selectively decreased the number of spontaneously active A10 (versus A9) dopamine neurons. FMPD did not produce catalepsy at doses lower than 25 mg/kg p.o. In Fos-induction studies, FMPD had an atypical antipsychotic profile in the striatum and nucleus accumbens and increased Fos expression in orexin-containing neurons of the hypothalamus. FMPD produced only a transient elevation of prolactin levels. These data indicate that FMPD is an orally available potent antagonist of dopamine D2, 5-HT2A, and 5-HT6 receptors and a weak antagonist of H1 and 5-HT2C receptors. FMPD has the potential to have efficacy in treating schizophrenia and bipolar mania with a low risk of treatment-emergent extrapyramidal symptoms, prolactin elevation, and weight gain. Clinical trials are needed to test these hypotheses.

Vanin-1-/- mice exhibit a glutathione-mediated tissue resistance to oxidative stress

Vanin-1 is an epithelial ectoenzyme with pantetheinase activity and generating the amino-thiol cysteamine through the metabolism of pantothenic acid (vitamin B(5)). Here we show that Vanin-1(-/-) mice, which lack cysteamine in tissues, exhibit resistance to oxidative injury induced by whole-body gamma-irradiation or paraquat. This protection is correlated with reduced apoptosis and inflammation and is reversed by treating mutant animals with cystamine. The better tolerance of the Vanin-1(-/-) mice is associated with an enhanced gamma-glutamylcysteine synthetase activity in liver, probably due to the absence of cysteamine and leading to elevated stores of glutathione (GSH), the most potent cellular antioxidant. Consequently, Vanin-1(-/-) mice maintain a more reducing environment in tissue after exposure to irradiation. In normal mice, we found a stress-induced biphasic expression of Vanin-1 regulated via antioxidant response elements in its promoter region. This process should finely tune the redox environment and thus change an early inflammatory process into a late tissue repair process. We propose Vanin-1 as a key molecule to regulate the GSH-dependent response to oxidative injury in tissue at the epithelial level. Therefore, Vanin/pantetheinase inhibitors could be useful for treatment of damage due to irradiation and pro-oxidant inducers.

Bicyclo[2.2.1]heptanes as novel triple re-uptake inhibitors for the treatment of depression

A series of substituted naphthyl containing chiral [2.2.1] bicycloheptanes were prepared utilizing asymmetric Diels-Alder chemistry. This paper describes structure-activity relationships in this series. The N-methyl 2-naphthyl analogue (16d) and its des-methyl analogue (17d) are active triple re-uptake inhibitors both in vivo and in vitro.

The synthesis and biological evaluation of non-peptidic matrix metalloproteinase inhibitors

Novel sulfonamide matrix metalloproteinase inhibitors of general formula (9) were synthesised by a route involving a stereoselective conjugate addition reaction. Enzyme selectivity was found to be dependant on the nature of the sulfonamide substituents. Compounds (9f, 9q) are potent selective collagenase inhibitors with good oral bioavailability.

The synthesis of novel matrix metalloproteinase inhibitors employing the Ireland-Claisen rearrangement

Matrix metalloproteinase inhibitors of general formula (1) were synthesised by a route involving an Ireland-Claisen rearrangement which enables systematic modification of the substituent alpha to the hydroxamic acid. An analogue (12c) possessing an alpha-cyclopentyl group is a potent broad spectrum inhibitor that displays high and sustained blood levels following oral dosing in both the rat and marmoset ex-vivo bioassays. This compound and analogues are also potent inhibitors of TNF alpha release.

Primary sclerosing cholangitis

Primary sclerosing cholangitis is a condition of unknown cause. It is recognized by liver dysfunction and its characteristic radiologic appearance, which is related to portal tract inflammation, bile duct proliferation, and periductal fibroses involving small intrahepatic and large extrahepatic ducts. The disease lasts about 10 years from the time of diagnosis. Primary sclerosing cholangitis is recognized by abnormal results on routine liver function tests or by the development of clinical jaundice. An autoimmune cause has been suggested because of its strong association with inflammatory bowel disease, certain antigens, AIDS, and immunoregulatory abnormalities. Results of medical management of sclerosing cholangitis have been disappointing. Immunosuppressive drugs, copper chelating agents, and antibiotics have failed to alter progression of the disease. Colectomy in patients with inflammatory bowel disease also has no influence. The judicious use of dilations of strictures, bypass procedures, or resection can palliate jaundice in patients with primary sclerosing cholangitis, but liver transplantation is the definitive treatment. Because palliative operations increase the hazards of liver transplantation, percutaneous dilations and stentings are preferred initially. Cirrhosis and portal hypertension are indications for transplantation. In the future, transplantation may be indicated earlier in the course of the disease.

Surgical aspects of sclerosing cholangitis. Results in 178 patients

Of 178 patients with sclerosing cholangitis treated since 1950, 88 patients had associated inflammatory bowel disease, 72 had no such history, and 18 had iatrogenic injury or stone disease. A total of 233 biliary operations were performed, with a 75% rate of temporary improvement after initial operation. Subsequent operations resulted in a lower success rate and a higher mortality rate. Radiologic findings included predominant extrahepatic, intrahepatic, and diffuse disease in 29%, 28%, and 43% of patients, respectively; no survival differences were noted. Seventy-five of one hundred three deaths (73%) were related to liver failure, bleeding, or sepsis. Of 14 patients undergoing portosystemic shunt, 13 died of surgical complications or related disease. Orthotopic liver transplantation was performed in 16 patients and resulted in eight deaths, mainly in patients who had previously undergone extensive surgical treatment. No survival differences were seen between the patients with inflammatory bowel disease, those without the condition, or those who had colectomy. Surgical treatment in patients with sclerosing cholangitis should be minimized. Orthotopic liver transplantation should be offered as the treatment of choice for patients with portal hypertension, refractory cholangitis, advanced cirrhosis, or progressive liver failure.

Bleeding stomal varices. The role of local treatment

The authors reviewed their experience with 12 patients (median age, 38 years; range, 24 to 66 years) who had bleeding stomal varices. Stomal variceal bleeding occurred between 1 and 11 years (median, 5.5 years) after creation of the stoma. Control of bleeding initially consisted of direct pressure; recurrent bleeding occurred in one patient who died before definitive therapy could be performed. The remaining 11 patients underwent a total of 18 additional procedures for control of bleeding stomal varices, including 9 local procedures, 8 portosystemic shunts, and 1 liver transplantation. Seven patients were dead of hepatic failure a median of 4 years (range, 1 to 9 years) after treatment. Recurrent bleeding occurred in three patients after local treatment and in one patient after a portosystemic shunt. Bleeding stomal varices are a manifestation of severe liver disease and portal hypertension. Although local procedures may be effective for initial control of bleeding, recurrent bleeding often occurs. Mortality is high because of the severity of the underlying liver disease.

Clinical and pathologic correlations in patients with periampullary tumors

Perioperative data on 87 patients undergoing pancreatoduodenectomy for periampullary tumors were correlated with pathologic study of operative specimens to identify the accuracy of diagnosis and the factors affecting survival. Accuracy of endoscopic retrograde cholangiopancreatography and computed tomography in locating lesions was 75% and 44%, respectively. Histologic diagnosis before or at the time of resection was available in only 61% of the patients. Carcinoma was correctly diagnosed clinically by the pathologist or the surgeon in 95% (83/87) of patients with 4 patients found to have benign disease on final pathologic examination. Intraoperative diagnosis of site of origin was incorrect in 18% (16/87) of patients. In 28% (23/83) of patients, pathologists identified nodal metastatic disease missed by the surgeon. Survival correlated with nodal and margin status and tumor grade. Tumor size demonstrated no predictive capacity. Although preoperative diagnostic accuracy is less than optimal, surgeons can usually diagnose malignant lesions but more often fail to identify tumor origin and nodal disease. We continue to advocate resection for patients with periampullary lesions thought to be malignant and resectable without a positive histologic diagnosis.

Apparent affinity of 1,3-dipropyl-8-cyclopentylxanthine for adenosine A1 and A2 receptors in isolated tissues from guinea-pigs

1. The classification of adenosine receptor subtypes (A1 and A2) in intact tissues has been based on the order of agonist potency. In this study the apparent affinity of 1,3-dipropyl-8-cyclopentylxanthine (CPX), an antagonist which has been reported to be A1 selective, and the non-selective antagonist 1,3-dimethyl-8-phenylxanthine (8PT) has been evaluated on isolated tissues from the guinea-pig. 2. The isolated tissues used were atria (bradycardic response, proposed A1 sub-type), aorta and trachea (relaxant response, proposed A2 sub-type). 3. Both the xanthines antagonized responses to adenosine in the three tissues but had little or no effect on responses to carbachol (atria), sodium nitrite (aorta) or isoprenaline (trachea). 4. pA2 values for 8PT were similar on the three tissues (6.3-6.7), however, the pA2 value for CPX on the atria (7.9-8.4) was greater than that on the aorta (6.6) or trachea (6.6). 5. These results support the suggestion that the adenosine receptors which mediate bradycardia in the atrium are of the A1 sub-type and that those which mediate relaxation in the aorta and trachea are of the A2 type.

Management of pancreatic fistulas

Conservative management of pancreatic fistulas resulting from trauma, operation for tumor, or operation for pancreatitis has met with variable success. To assess optimal management strategies and outcome, we reviewed the records of 35 patients with external pancreatic fistulas (26 patients), pancreatic ascites (6 patients), or pancreatic pleural effusion (3 patients). Treatment included no operation in 5 patients, oversewing of the fistula in 7 patients, internal drainage in 11 patients, and resection in 12 patients. One (3%) postoperative death occurred. The overall rate of operative success was 83% (25 patients). The incidence of recurrent fistulas was about the same regardless of the procedure. Patients treated successfully without operation did not have pancreatitis as an underlying disease. Patient selection is of great importance in the decision to resect or to drain and is based in part on imaging the pancreatic duct and fistula.

Liver abscess. The need for complete gastrointestinal evaluation

The cause of liver abscess is frequently obscure at initial presentation. We reviewed the medical records of 20 patients with pyogenic liver abscess over a 6-year period from 1981 to 1987. Liver abscess was suspected in only 3 patients on admission; the most common initial diagnosis was fever of unknown origin. Subsequently, the origin of the abscess was found to be intestinal in 7 patients, pancreatobiliary in 11 patients, and cryptogenic in 2 patients. Eleven patients underwent percutaneous transhepatic drainage of the abscess as the initial treatment, while open operation was the initial treatment in 9 patients. Percutaneous transhepatic drainage was ultimately successful in only 4 patients (36%). In the absence of an obvious pathologic condition of the biliary tract, all patients should undergo full gastrointestinal evaluation.

Glucagonoma presenting as morbid obesity

A case is described that represents the only reported patient with glucagonoma syndrome and morbid obesity. The diagnosis of glucagonoma should be considered in any patient with the classic criteria despite weight gain. The criteria for diagnosis of glucagonoma are 1) the presence of a glucagon-secreting tumor, 2) hyperglucagonemia, and 3) the clinical manifestations of either necrolytic migratory erythema, glucose intolerance, or hypoaminoacidemia.

Therapeutic colonoscopy in the treatment of colonic pseudo-obstruction

Colonic pseudo-obstruction has been recognized since Ogilvie described this disease in 1948. Metabolic, surgical, and medical causes have been implicated at various times. Treatment has included surgical decompression by cecostomy and colectomy. Successful nonoperative decompression by colonoscopy was first reported by Kukora and Dent in 1977. Since that report several authors have reported their results using this technique. Presented here is a series of nine patients with colonic pseudo-obstruction treated initially with colonoscopy. Patients presented with a variety of associated conditions, including post operative patients, orthopedic injuries, metastatic carcinoma, and an unusual case after a normal vaginal delivery. Eight patients responded well to colonoscopic decompression. One patient, the second in the series, was unable to be decompressed with colonoscopy and underwent a cecostomy under local anesthesia. Successive colonoscopy may be required to allow restoration of normal colonic function, as was the case in seven of our patients. One death occurred, due to unrelated causes. The authors have found colonoscopy to be a safe and reliable therapy for colonic pseudo-obstruction.

Effects of soil water supply and temperature on the photosynthesis of white clover and paspalum in irrigated pastures

Field canopy chambers were used to measure the effect of a range of soil water contents from surface ponding to very dry soil and the effect of high summer temperatures on the photosynthesis of irrigated white clover and paspalum pastures. Water was ponded for 5-12 days on swards of white clover and paspalum at full cover and on others that had been defoliated to a height of 50 mm. Photosynthetic rate was monitored each day and compared with a non-ponded control. In all cases there was little response in photosynthetic rate to ponding either with or without supplemental nitrogen fertiliser. Photosynthesis of full swards of white clover and paspalum was monitored during a drying cycle following irrigation and compared with the photosynthesis of a well-watered control. Soil water deficit was expressed in terms of cumulative evaporation minus rainfall (mm E - R) after irrigation. Water deficit stress reduced the maximum photosynthetic rate of white clover by 50% (from 0.8 mg CO2/m2.s at 25 mm E - R to 0.4 mg CO2/m2.s at 75 mm E - R), but the photosynthetic rate of paspalum did not decline until 70 mm E - R. At high irradiance, temperatures between 24 and 33�C had little effect on the photosynthetic rate of well-watered white clover, whereas the rate in paspalum was higher at temperatures between 29 and 38�C than at temperatures of 24-29�C. The slow surface drainage and subsequent rapid drying of the root-zone of flood irrigated soils, combined with the high temperatures experienced in northern Victoria during summer, favour paspalum and severely limit the productivity of white clover.

Productivity of irrigated pastures following paraplowing and gypsum slotting of subsoil exposed by laser landforming dash a short term study

The effect of two soil amelioration techniques (paraplow and gypsum-enriched slots) on the productivity of white clover/ryegrass pasture was assessed by monitoring plant and soil water status and canopy gasexchange during an irrigation cycle. The soil was a dense clay, exposed when the topsoil was removed during laser landforming. Pasture growth on such exposed subsoils is very slow.All parameters of soil and plant water status indicated that there was some benefit from amelioration, with slots > paraplow > control. This trend was reflected in canopy photosynthesis. The photosynthetic efficiencies of canopies declined rapidly after 40 mm Class A pan evaporation less rainfall (E- R) in the control and after 50 mm E - R in the paraplowed treatments. At the end of the irrigation cycle (72 mm E - R) the efficiencies of the control and paraplow were about 20% and 50%, respectively, of the wellwatered. The efficiency of the canopy in the slot treatment remained high throughout.Without soil amelioration, pastures grown on exposed subsoil cannot maintain high levels of photosynthesis during a normal irrigation cycle in summer. More frequent irrigation or soil amelioration (or both) are required if pasture production on exposed subsoil is to be dramatically improved.

Cadmium-induced lung injury: cell kinetics and long-term effects

The effects of exposure to CdCl2 aerosols followed by hyperoxia were studied in mouse lung. Special emphasis was placed on analysis of cell proliferation following injury. Male Balb/c mice were exposed to aerosols of 4.9 micrograms Cd/liter for 1 hr while controls were exposed to water aerosols. Immediately after, half of each group was placed in 80% O2 for 6 days, while the rest were left in room air. Three endpoints were used to assess lung injury; measurement of hydroxyproline, [14C]thymidine incorporation into DNA, and histopathology. Parenchymal and bronchiolar labeling indices were determined following autoradiography. A 1-hr exposure to CdCl2 aerosols caused marked cell proliferation in the lung with the peak of cell labeling occurring at Day 5. In animals exposed to both CdCl2 + 80% O2, the cell labeling peak was delayed until Day 9. Cell differentiation studies showed a delay in the peak of type II epithelial cell and endothelial cell division when CdCl2 exposure was followed by the 80% O2 treatment. On Day 15 most of the labeled cells were identified as interstitial cells in both treated groups. Bronchiolar cell labeling was suppressed at the early time period in the Cd + O2 group. With time, the histologically visible lung lesions tended to resolve in animals exposed to CdCl2 or CdCl2 and 80% O2, whereas total pulmonary hydroxyproline remained at all times (3, 6, and 12 months) significantly higher in Cd-treated animals when compared to controls. It was concluded that acute lung injury by a toxic inhalant can be amplified if there is an initial delay in pulmonary cell proliferation following an acute insult.

The end of the road: residential disposals in the Scottish children's hearings system

In a study of a representative sample of 301 "children's hearings", particular attention was given to 27 cases in which the child was committed to a List D school. Because the Scottish juvenile justice system has an explicit commitment to promoting the welfare of the children with whom it deals, the decisions were examined with special reference to the objectives that the hearing members hoped to achieve. These decisions could be divided into: (1) those which reflected only a sense that all alternatives had been exhausted; (2) those which aimed to ensure that the child received formal education or was placed in an environment which would help resolve his personal difficulties; (3) those designed to protect the child from family stresses or to achieve some other specific purpose. Since decisions under (1) are incompatible with the formal philosophy of the system, most of those under (2) entail no knowledge of the effectiveness of List D schools for the purposes in question, and some of those under (3) were wholly misconceived, it is concluded that there are some significant inconsistencies between the system's ideology and the actual practice of its members.

Potentiating effects of oxygen in lungs damaged by methylcyclopentadienyl manganese tricarbonyl, cadmium chloride, oleic acid, and antitumor drugs

The intraperitoneal administration of methylcyclopentadienyl manganese tricarbonyl (MMT) and cyclophosphamide, exposure to an aerosol of cadmium chloride, intravenous administration of oleic acid, and intratracheal instillation of bleomycin to young female BALB/c mice or CD/CR rats result in acute lung injury. Pulmonary morphology and lung collagen content were examined in animals treated with these chemicals alone or in combination with an elevated oxygen concentration (80%) in the inspired air. In mice, the development of fibrosis could be significantly enhanced if animals treated with MMT, cadmium chloride, cyclophosphamide, or bleomycin were exposed to 80% oxygen immediately following exposure to these agents. In rats only cyclophosphamide- and bleomycin-induced acute lung injury was potentiated by hyperoxia, resulting in significant enhancement of lung collagen content. The pathogenesis responsible for this differential species response of pulmonary injury to hyperoxia remains to be investigated.

The role of "children's hearings" in child abuse and neglect

The juvenile justice system established in Scotland in 1971, in which lay volunteers play a central part, provides a framework for making decisions about children in need of care and protection as well as those who have committed delinquent acts. Although cases of child abuse and neglect have come increasingly to the attention of children's hearings in recent years, they nevertheless constitute a small fraction of a workload dominated by cases of delinquency and truancy. A recent Scotland-wide study of the hearings system therefore gave only limited attention to the processing of abuse and neglect referrals. As a step towards rectifying this imbalance, a separate enquiry was carried out in 1981, when 43 such hearings were systematically observed and the participating panel members interviewed. Examination of these results indicates a heavy dependence on social workers' recommendations, a reluctance to open up sensitive areas for discussion, even though these may be of central importance, and an apparent lack of curiosity about the arrangements made for children removed from their homes, and the implications of these. In general, it is concluded that the anxiety generated by child abuse and neglect has prevented panel members from recognizing the distinctive features of their role in the decision-making process and has led them to fall back on an inappropriate model of practice derived from delinquency hearings. An alternative model is outlined.