Near-Sun observations of an F-corona decrease and K-corona fine structure.

Remote observations of the solar photospheric light scattered by electrons (the K-corona) and dust (the F-corona or zodiacal light) have been made from the ground during eclipses1 and from space at distances as small as 0.3 astronomical units2-5 to the Sun. Previous observations6-8 of dust scattering have not confirmed the existence of the theoretically predicted dust-free zone near the Sun9-11. The transient nature of the corona has been well characterized for large events, but questions still remain (for example, about the initiation of the corona12 and the production of solar energetic particles13) and for small events even its structure is uncertain14. Here we report imaging of the solar corona15 during the first two perihelion passes (0.16-0.25 astronomical units) of the Parker Solar Probe spacecraft13, each lasting ten days. The view from these distances is qualitatively similar to the historical views from ground and space, but there are some notable differences. At short elongations, we observe a decrease in the intensity of the F-coronal intensity, which is suggestive of the long-sought dust free zone9-11. We also resolve the fine-scale plasma structure of very small eruptions, which are frequently ejected from the Sun. These take two forms: the frequently observed magnetic flux ropes12,16 and the predicted, but not yet observed, magnetic islands17,18 arising from the tearing-mode instability in the current sheet. Our observations of the coronal streamer evolution confirm the large-scale topology of the solar corona, but also reveal that, as recently predicted19, streamers are composed of yet smaller substreamers channelling continual density fluctuations at all visible scales.

Characteristics of coexisting attractors and ghost orbiting in an optomechanical microresonator.

We explore the nonlinear interactions of an optomechanical microresonator driven by two external optical signals. Optical whispering-gallery waves are coupled to acoustic surface waves of a fused silica medium in the equatorial plane of a generic microresonator. The system exhibits coexisting attractors whose behaviors include limit cycles, steady states, tori, quasi-chaos, and fully developed chaos with ghost orbits of a known attractor. Bifurcation diagrams demonstrate the existence of self-similarity, periodic windows, and coexisting attractors and show high-density lines within chaos that suggests a potential ghost orbit. In addition, the Lyapunov spectral components as a function of control parameter illuminate the dynamic nature of attractors and periodic windows with symmetric and asymmetric formations, their domains of existence, their bifurcations, and other nonlinear effects. We show that the power-shift method can access accurately and efficiently attractors in the optomechanical system as it does in other nonlinear systems. To test whether the ghost orbit is the link between two attractors interrupted by chaos, we examine the elements of the bifurcation diagrams as a function of control parameter. We also use detuning as a second control parameter to avoid the chaotic region and clarify that the two attractors are one.

Predicting attractor characteristics using Lyapunov exponents in a laser with injected signal.

Coexisting attractors are studied in a single-mode coherent model of a laser with an injected signal. We report that every attractor has a unique Lyapunov exponent (LE) pattern that is choreographed by the subtle variations in the attractor's dynamics and circumscribed by a common Lyapunov spectral pattern that begins and ends with two-zero LEs. Lyapunov spectra form symmetric-like and asymmetric bubbles; the former foreshadows an attractor's proximity to the cusp of an eminent change in dynamics and the latter indicates the presence of a bifurcation. We show that the peak values of the asymmetric bubbles are always associated with two-zero LEs; in fact, they are allied inseparably in forecasting period-doubling episodes. The two-zero LEs' predictor of torus dynamics is refined to include the convergence of three LEs to a triplet of zeros as a precursor to the two-zero spectra. We report that the long-standing two-zero LEs' signature is a necessary but not sufficient condition for predicting attractors and their dynamic conditions. The evolution of the attractor volume as a function of the injected signal is compared to the spectral formation of the attractor; we report slope changes and points of inflections in the volume trajectory where spectral changes indicate dynamic changes. Attractor viability is tested preliminarily by including random low-level noise in the frequency of the injected signal.

Differentiating psychopathy from antisocial personality disorder: a triarchic model perspective.

BACKGROUND: The triarchic model of psychopathy characterizes the disorder in terms of three distinguishable phenotypic facets: disinhibition, meanness and boldness. The present study sought to (1) inform current debates regarding the role of boldness in the definition of psychopathy and (2) clarify boundaries between psychopathy and antisocial personality disorder (ASPD). METHOD: This study evaluated the degree to which facets of the triarchic model are represented in the most widely used clinical inventory for psychopathy, the Psychopathy Checklist - Revised (PCL-R), in comparison with ASPD as defined by DSM-IV criteria. Adult male offenders from two distinct correctional settings (n = 157 and 169) were investigated to ensure replicability of findings across samples exhibiting high base rates of psychopathy and antisocial behavior. RESULTS: We found evidence for convergent and discriminant validity of the three triarchic facets in predicting symptomatic components of psychopathy as assessed by the PCL-R. Additionally, and crucially vis-à-vis current debates in the field, we found that boldness contributed incrementally (over and above disinhibition and meanness) to prediction of PCL-R psychopathy, in particular its interpersonal style component, but not ASPD. CONCLUSIONS: The three distinct facets of the triarchic model of psychopathy are represented clearly and distinctly in the PCL-R, with boldness through its interpersonal facet, but not in DSM-defined ASPD. Our findings suggest that boldness is central to diagnostic conceptions of psychopathy and distinguishes psychopathy from the more prevalent diagnosis of ASPD.

Insulin gene region-encoded susceptibility to type 1 diabetes is not restricted to HLA-DR4-positive individuals.

Type 1 or insulin-dependent diabetes mellitus (IDDM) is an autoimmune disease of the insulin-producing pancreatic beta-cells which is determined by both genetic and environmental factors. The major histocompatibility complex and the insulin gene region (INS) on human chromosomes 6p and 11p, respectively, contain susceptibility genes. Using a mostly French data set, evidence for linkage of INS to IDDM was recently obtained but only in male meioses (suggesting involvement of maternal imprinting) and only in HLA-DR4-positive diabetics. In contrast, we find evidence for linkage in both male and female meioses and that the effect of the susceptibility gene(s) in the INS region is not dependent on the presence of HLA-DR4.

Long-term nitrate increases in two oligotrophic lakes, due to the leaching of atmospherically-deposited N from moorland ranker soils.

During the last 50 years nitrate concentrations in Buttermere and Wastwater (Cumbria, UK) have risen significantly, by 70 and 100%, respectively. By estimating contemporary nitrate fluxes in the lakes' catchments and in sub-catchments and comparing them with the fractional areas of different soil types, it is deduced that the surface water nitrate is derived almost entirely from organic-rich ranker soils that have a limited ability to retain atmospherically-deposited nitrogen. Little or no nitrate leaches from the other major soil type, a brown podzol, despite it having a lower C:N ratio (12.0 g g(-1)) than the ranker (17.0 g g(-1)), nor is there much contribution from the small areas of improved (chemically fertilised) grassland within the catchments. Although some nitrate leaching is occurring, total N losses are appreciably smaller than atmospheric inputs, so the catchment soils are currently accumulating between 3 and 4 g N m(-2) a(-1).

Estimating uncertainty in terrestrial critical loads and their exceedances at four sites in the UK.

Critical loads are the basis for policies controlling emissions of acidic substances in Europe and elsewhere. They are assessed by several elaborate and ingenious models, each of which requires many parameters, and have to be applied on a spatially-distributed basis. Often the values of the input parameters are poorly known, calling into question the validity of the calculated critical loads. This paper attempts to quantify the uncertainty in the critical loads due to this "parameter uncertainty", using examples from the UK. Models used for calculating critical loads for deposition of acidity and nitrogen in forest and heathland ecosystems were tested at four contrasting sites. Uncertainty was assessed by Monte Carlo methods. Each input parameter or variable was assigned a value, range and distribution in an objective a fashion as possible. Each model was run 5000 times at each site using parameters sampled from these input distributions. Output distributions of various critical load parameters were calculated. The results were surprising. Confidence limits of the calculated critical loads were typically considerably narrower than those of most of the input parameters. This may be due to a "compensation of errors" mechanism. The range of possible critical load values at a given site is however rather wide, and the tails of the distributions are typically long. The deposition reductions required for a high level of confidence that the critical load is not exceeded are thus likely to be large. The implication for pollutant regulation is that requiring a high probability of non-exceedance is likely to carry high costs. The relative contribution of the input variables to critical load uncertainty varied from site to site: any input variable could be important, and thus it was not possible to identify variables as likely targets for research into narrowing uncertainties. Sites where a number of good measurements of input parameters were available had lower uncertainties, so use of in situ measurement could be a valuable way of reducing critical load uncertainty at particularly valuable or disputed sites. From a restricted number of samples, uncertainties in heathland critical loads appear comparable to those of coniferous forest, and nutrient nitrogen critical loads to those of acidity. It was important to include correlations between input variables in the Monte Carlo analysis, but choice of statistical distribution type was of lesser importance. Overall, the analysis provided objective support for the continued use of critical loads in policy development.

Vitamin C Supplementation, APOE4 Genotype and Cognitive Functioning in a Rural-Dwelling Cohort.

OBJECTIVE: Apolipoprotein E4 (APOE4) genotype has been implicated as a moderating factor in cognitive function studies. Although prior studies have suggested that vitamin C is associated with better cognitive function in elders, link between the two has been mixed. Limited data exist as to whether the APOE4 genotype influences these associations. Therefore, this study sought to determine whether the association between vitamin C and cognition in a rural community dwelling cohort differs by the APOE4 genotype. DESIGN AND PARTICIPANTS: Data were analyzed on 582 participants (n=183 men; n=399 women) from a rural community-based cohort. Cognition was assessed using the Repeatable Battery for the Assessment of Neuropsychological Status and The Executive Interview. APOE genotyping was ascertained by standard methods. The relation between vitamin C supplementation and cognition were analyzed first with ANOVA and then ANCOVA with age, gender, education as covariates. Analyses were initially run in the full sample and then split by APOE4 presence (yes/no). RESULTS: Overall, Vitamin C supplementation was associated with significantly better immediate memory (p=0.04), visuospatial skills (p=0.002), language (p=0.01), and global cognitive functioning (p=0.006). Among APOE4 non-carriers, vitamin C supplementation was positively associated with immediate memory (F[1,392] =6.7, p=0.01), visuospatial skills (F[1,391]=10.6, p=0.001), language (F[1,392]=13.0, p<0.001), attention (F[1,386]=7.9, p=0.005, and global cognition (F[1,382]=11.0, p=0.001. However, there was no significant link between vitamin C supplementation and cognition among APOE4 carriers. CONCLUSION: Vitamin C supplementation was found to be positively associated with cognition among this rural-dwelling community-based sample; however, the associations appeared to differ by APOE4 status. These data may suggest that targeted genotype-specific cognitive enhancement studies are needed to clarify the potential benefits of vitamin C supplementation.

Long noncoding RNA lincRNA-p21 is the major mediator of UVB-induced and p53-dependent apoptosis in keratinocytes.

LincRNA-p21 is a long noncoding RNA and a transcriptional target of p53 and HIF-1α. LincRNA-p21 regulates gene expression in cis and trans, mRNA translation, protein stability, the Warburg effect, and p53-dependent apoptosis and cell cycle arrest in doxorubicin-treated mouse embryo fibroblasts. p53 plays a key role in the response of skin keratinocytes to UVB-induced DNA damage by inducing cell cycle arrest and apoptosis. In skin cancer development, UVB-induced mutation of p53 allows keratinocytes upon successive UVB exposures to evade apoptosis and cell cycle arrest. We hypothesized that lincRNA-p21 has a key functional role in UVB-induced apoptosis and/or cell cycle arrest in keratinocytes and loss of lincRNA-p21 function results in the evasion of apoptosis and/or cell cycle arrest. We observed that lincRNA-p21 transcripts are highly inducible by UVB in mouse and human keratinocytes in culture and in mouse skin in vivo. LincRNA-p21 is regulated at the transcriptional level in response to UVB, and the UVB induction of lincRNA-p21 in keratinocytes and in vivo in mouse epidermis is primarily through a p53-dependent pathway. Knockdown of lincRNA-p21 blocked UVB-induced apoptosis in mouse and human keratinocytes, and lincRNA-p21 was responsible for the majority of UVB-induced and p53-mediated apoptosis in keratinocytes. Knockdown of lincRNA-p21 had no effect on cell proliferation in untreated or UVB-treated keratinocytes. An early event in skin cancer is the mutation of a single p53 allele. We observed that a mutant p53(+/R172H) allele expressed in mouse epidermis (K5Cre(+/tg);LSLp53(+/R172H)) showed a significant dominant-negative inhibitory effect on UVB-induced lincRNA-p21 transcription and apoptosis in epidermis. We conclude lincRNA-p21 is highly inducible by UVB and has a key role in triggering UVB-induced apoptotic death. We propose that the mutation of a single p53 allele provides a pro-oncogenic function early in skin cancer development through a dominant inhibitory effect on UVB-induced lincRNA-p21 expression and the subsequent evasion of UVB-induced apoptosis.

Efficient control of tetracycline-responsive gene expression from an autoregulated bi-directional expression vector.

The tetracycline-responsive expression system is based on the ability of the chimeric tTA and rtTA transactivators to stimulate specifically transcription from a companion synthetic CMV* or TK* promoter element, and can provide tightly regulated gene expression that can be induced up to five orders of magnitude in cultured cells and transgenic mice. A major problem with the system is that high level expression of the tTA or rtTA transactivators causes cellular toxicity. Under conditions of prolonged expression this results in selective pressure against the stable incorporation of vectors expressing the tTA or rtTA transactivators, and makes the generation of stable cell lines and transgenic mice problematic. In this report we describe the development of a set of autoregulated bi-directional expression vectors in which the weaker TK* promoter is used to direct expression of the rtTA or tTA transactivator and the stronger CMV* element is used to direct cDNA expression. In this format the transactivator and response elements are encoded on the same vector, which simplifies the system and ensures that gene expression is effectively skewed in favor of the cDNA while maintaining a continuously low level of transactivator expression. We find that such an autoregulated system works equally well for both the tTA and rtTA transactivators, provided that they contain a nuclear localization signal. Similar to other versions of the tetracycline-responsive expression system, gene expression is tightly regulated and can be efficiently switched between the off and on expression states by doxycycline. In contrast with other tetracycline-responsive systems, however, expression of the rtTA and tTA transactivators from the autoregulated TK* promoter is low enough such that there is no cellular toxicity associated with either expression state. By incorporating a selectable marker into these vectors, all of the components required for using the system are now contained on a single plasmid construct, and we find that this format provides a more reliable and greatly simplified method for the generation of stable cell lines.

Polymorphism of the TRAP gene of Plasmodium falciparum.

Natural sequence variation of the thrombospondin related anonymous protein (TRAP) gene of Plasmodium falciparum has been investigated by DNA analysis following the polymerase chain reaction amplification, and this shows the gene to be highly polymorphic. The region containing the sequence motif Trp-Ser-Pro-Cys-Ser-Val-Thr-Cys-Gly (WSPCSVTCG), common to TRAP, the circumsporozoite protein, properdin, and thrombospondin, was invariant. Elsewhere in the molecule, over 50 amino acid substitutions are described including the insertion of an in-frame, small-variable tandemly repeating motif between amino acid residues 352 and 353. Only one silent mutation was observed. Most nucleotide changes that occur in the first two codon positions result in conservative amino acid changes. Restriction fragment length polymorphism (RFLP) analysis was used to examine inheritance of TRAP in a cross between the HB3 and 3D7 clones of P. falciparum. Out of nine progeny examined, four possessed the HB3 gene and five the 3D7 gene. The TRAP gene hybridized to chromosome 13. Previous work has shown that a subtelomeric region of chromosome 13 from the 3D7 parent (marked by the HRP-III gene) was favoured strongly in this cross. The TRAP gene, however, is over 1 Mb away from this subtelomeric region and exhibits no such linkage because of chromosome crossovers. Five geographically separate isolates shared the same TRAP sequence as well as the same variant of the Th2R/Th3R region from the circumsporozoite protein. The correlation between independent markers in these isolates suggests that they have a common provenance.

One-drug versus two-drug antibiotic therapy in pediatric perforated appendicitis: a prospective randomized study.

A prospective randomized study was undertaken to compare the use of the combination of gentamicin and clindamycin with single agent, cefoxitin, in the treatment of perforated appendicitis in the pediatric patient. In a 3-year period from 1986 to 1989, 56 patients with perforated appendicitis were randomized. Twenty-nine patients received cefoxitin, and 27 patients received gentamicin and clindamycin. Antibiotics were started before operation and continued for a minimum of 6 days after operation. Skin and subcutaneous tissues were left open at surgery and closed secondarily after day 3, if they appeared to be clean. Wounds were considered infected if they developed increased purulence with positive wound cultures. Age range was similar in both groups, with a mean of 9 years (range, 1 to 17 years); 28 were boys and 28 were girls. No changes in antibiotics were required for reasons of susceptibility. No adverse drug reactions occurred in either group. The most common organisms were Escherichia coli in 35 cases (62%) and Bacteroides species in 26 cases (46%). No difference was noted in infection complications in the two groups nor in length of hospital stay. Therefore, no difference is evident in the use of cefoxitin versus gentamicin and clindamycin in the treatment of perforated appendicitis in terms of disease or drug-related complications.

Prediction of operative cholangiography in patients undergoing elective cholecystectomy with routine liver function chemistries.

A retrospective reviews of 195 consecutive patients who underwent elective cholecystectomy and operative cystic duct cholangiography (OCDC) were reviewed to establish criteria to correlate the preoperative laboratory data of liver chemistry tests and the actual biliary tract disease found in each patients. Patients who had a history of jaundice or other clinical indication for common bile duct exploration were excluded from this study. The patients were divided into four groups based on the results of the OCDC: I negative, II false positive, III false negative, and IV positive for choledocholithiasis. The results of the preoperative liver chemistry studies of the patients in each of the four groups were analyzed by the chi 2 method. The four liver chemistry tests were lactate dehydrogenase, SGOT, bilirubin, and alkaline phosphatase. When results of all preoperative liver chemistry tests were normal, there was no incidence of choledocholithiasis. As the number of chemistry test result elevations increased from one to four, the incidence of choledocholithiasis increased from 17% to 50% (p less than 0.001). Preoperative liver chemistry tests in selected patients undergoing elective cholecystectomy may provide a valuable indicator to the surgeon as to whether an OCDC should be performed at the time of surgery.

Water vapor pressure calculation.

Accurate calculation of water vapor pressure for systems saturated with water vapor can be performed using the Goff-Gratch equation. A form of the equation that can be adapted for computer programming and for use in electronic databases is provided.

Drainage following radical hysterectomy and pelvic lymphadenectomy: dogma or need?

OBJECTIVE: To compare the incidence of lymphocyst formation and postoperative morbidity in patients drained or not drained following radical hysterectomy and pelvic lymph node dissection for cervical or endometrial malignancy. METHODS: A prospective study was undertaken of consecutive patients undergoing radical hysterectomy and pelvic lymphadenectomy at the Regional Department of Gynaecological Oncology, Gateshead, United Kingdom, between February 1992 and September 1994. A Piver type II procedure was performed with nonclosure of the vaginal cuff and pelvic peritoneum. Patients were randomized at the end of surgery to have either two suction drains inserted along the pelvic sidewalls or to have no drains inserted. The detection of lymphocysts was made by clinical examination and abdominal ultrasound scan performed 8 weeks postoperatively. RESULTS: Eight patients were excluded from the study when drains were deemed necessary to assess postoperative blood loss. Fifty-one were randomized to drains, and 49 to no drains. The detection of lymphocysts by ultrasound and clinical examination in the drained group (15.6 and 5.9%, respectively) was not significantly different from the group not drained (17.4 and 6.1%, respectively). There was no difference in postoperative morbidity in the two groups. CONCLUSION: There appears to be no advantage to the routine use of pelvic suction drainage following radical hysterectomy and pelvic lymphadenectomy.

Pneumothorax in the Marfan syndrome: prevalence and therapy.

At least twenty-four reports of pneumothorax associated with the Marfan syndrome have appeared in the medical literature, but the frequency and optimal method of treatment remain unclear. We conducted a retrospective review of medical records from one genetics clinic and found that the frequency of spontaneous pneumothorax in patients older than 12 years with Marfan's syndrome was 4.4% (11 out of 249). Men were more commonly, but no more severely, affected than women. Seven patients had recurrent or bilateral pneumothorax. In 9 of the 11 patients, apical bullae were present and detectable on chest radiograph. Pneumothorax frequently recurred if not treated by resection of the offending bullae. We recommend that all adolescent and adult patients with the Marfan syndrome undergo chest radiography for ascertainment of the gross pathological condition of the lung. Definitive surgical treatment should be performed at the first occurrence of pneumothorax because of the high rate of recurrence after treatment with a chest tube, with or without pleurodesis.

Analysis of residents' performances on the In-Training Examination of the American Board of Anesthesiology-American Society of Anesthesiologists.

An analysis of the results of the In-Training Examination of the American Board of Anesthesiology-American Society of Anesthesiologists has been developed using a new question-categorization method and a new form of calculation, the resident index score. Resident index scores permit comparison of the performance of any program's residents with the performance of all U.S. residents who took the examination. This study analyzed examination results from eight residency programs for a five-year period, 1983-1987. Statistically significant differences in the residents' performances were found both within and among the residency programs during this time. Areas of educational strength and weakness were identified by levels of training for each program. The analyses of the individual programs' results were provided to the respective program directors on a confidential basis, and have been used to change curriculum content, modify lectures for residents, and provide structured review for residents. Similar analyses can be provided as a service to other residency program directors.

A double-blind comparative study of fluoxetine and dothiepin in the treatment of depression in general practice.

Fluoxetine, a selective inhibitor of 5-HT uptake, was compared to dothiepin in a double-blind study of 6 weeks duration in 100 depressed patients (male and female) drawn from 8 general practices. Only those who scored at least 17 on the first 17 questions of the Hamilton Psychiatric Rating Scale for Depression (HAM-D) were selected. Both groups improved throughout the trial, though the dothiepin treated patients tended to improve quicker. However, by the end of the trial there was no statistically significant difference between the 2 groups. Subset analyses of HAM-D scores associated with anxiety and sleep revealed no statistically significant differences between the 2 treatments though improvement in anxiety scores was marginally greater for those receiving fluoxetine by the end of the trial. Other global assessments by patients and doctors confirmed the changes in HAM-D scores. Statistically significant weight changes occurred between visits 1 and 5. Whereas fluoxetine-treated patients lost weight (p less than 0.05), dothiepin-treated patients gained weight (p = 0.05) over this period. Adverse effects were reported in 27 patients given fluoxetine and 20 dothiepin. Of these, 14 fluoxetine and 7 dothiepin-treated patients withdrew before the end of the trial. The most common adverse effects were nausea, vomiting and diarrhoea in the fluoxetine group and tiredness, drowsiness and diarrhoea in the dothiepin group. There were no haematological or clinical chemistry changes.

Understanding factors that influence smoking uptake.

OBJECTIVE: To explore relationships between patterns of smoking uptake and social context and attitudinal variables. DESIGN: Cross sectional survey. SETTING: Public schools in Tucson, Arizona and Albuquerque, New Mexico. PARTICIPANTS: 982 children in grades 6-9 (ages 11-15 years). MAIN OUTCOME MEASURES: Items measuring smoking history, nicotine dependence and quit attempts, susceptibility to smoking in the future, smoking norms, use of other tobacco products, attitudes toward smoking, and demographic characteristics. RESULTS: Overall, 43% of children had smoked a cigarette and 57% had never used them. Ever smokers lived in social contexts with more smoking and where smoking was normative. Among never users, 25% are susceptible to smoking; these children have positive attitudes toward smoking, do not feel social pressure to stay off cigarettes, and had more friends who smoked. Among ever users, 36% were currently smoking in the past 30 days. Current users also lived in social context with more smoking and had positive attitudes toward smoking. Most users had tried to stop smoking. Only 9% of current users smoked daily; 29% had not smoked a whole cigarette. Greater cigarette consumption was associated with more favourable attitudes toward smoking. Most of past users were in early uptake: 95% had smoked less than 100 cigarettes but 49% were susceptible to smoking again. CONCLUSIONS: There is promise in differentiating subgroups among the never, past and current use of cigarettes. Susceptibility within each of these groups was associated with similar patterns of attitudes and social context. These patterns in smoking uptake need to be confirmed prospectively.

The clinical and radiological features of cholecystocolic fistulae.

The clinical and radiological features of seven patients presenting with cholecystocolic fistulae are reviewed. The majority of the patients were elderly (age range 43-85 years, mean 70.7 years) and there was a female preponderance (6:1). The condition usually has a benign clinical course. Diarrhoea was the most common presenting symptom and the typical clinical features of gallbladder disease were absent. Cholangitis occurred in only one patient. The time between onset of symptoms and diagnosis varied from 1 week to 2 years (mean 22 weeks). In only one patient was the diagnosis of biliary-intestinal fistula suspected on the basis of the plain abdominal radiograph (Case 5). A diagnosis of cholecystocolic fistula was established by barium enema (5 cases), endoscopic retrograde cholangiopancreatography (ERCP) (1 case) and diagnostic laparotomy (1 case). The only cause identified in this series was acute or chronic cholecystitis.