Wildfire smoke impacts activity and energetics of wild Bornean orangutans.

Indonesia's peatlands experience frequent and intense wildfires, producing hazardous smoke with consequences for human health, yet there is a lack of research into adverse effects on wildlife. We evaluated the effects of smoke on the activity and energy balance of Bornean orangutans (Pongo pygmaeus wurmbii) in a peat swamp forest at the Tuanan Research Station, Central Kalimantan. We collected behavioural data and urine samples from four adult flanged males before, during, and after wildfires between March 2015 and January 2016. During fires, particulate matter (PM10) concentrations were hazardous. Orangutans increased rest time during and after the smoke period, and decreased travel time and distance and increased fat catabolism post-smoke. The increase in post-smoke ketones was not related to changes in caloric intake and was likely due to an increase in energy expenditure, possibly related to immune response. Results show that wildfire smoke negatively affects orangutan condition, and sustained research is needed to assess the magnitude of the threat to the long-term viability of this Critically Endangered species.

Current UK practice in emergency laparotomy.

INTRODUCTION: Emergency laparotomy is a common procedure, with 30,000-50,000 performed annually in the UK. This large scale study reports the current spectrum of emergency laparotomies, and the influence of the surgical procedure, underlying pathology and subspecialty of the operating surgeon on mortality. METHODS: Anonymised data on consecutive patients undergoing an emergency laparotomy were submitted for a three-month period. The primary outcome measure was unadjusted 30-day mortality. Appendicectomy and cholecystectomy were among the procedures excluded. RESULTS: Data from 1,708 patients from 35 National Health Service hospitals were analysed. The overall 30-day mortality rate was 14.8%. 'True' emergency laparotomies (ie those classified by the National Confidential Enquiry into Patient Outcome and Death as immediate or urgent) comprised 86.5% of cases. The mortality rate rose from 8.0% among expedited cases to 14.3% among urgent cases and to 25.7% among laparotomies termed immediate. Among the most common index procedures, small bowel resection exhibited the highest 30-day mortality rate of 21.1%. The presence of abdominal sepsis was associated with raised 30-day mortality (17.5% in the presence of sepsis vs 12.6%, p=0.027). Colorectal procedures comprised 44.3% and within this group, data suggest that mortality from laparotomy may be influenced by surgical subspecialisation. CONCLUSIONS: This report of a large number of patients undergoing emergency laparotomy in the UK confirms a remarkably high mortality by modern standards across the range. Very few pathologies or procedures can be considered anything other than high risk. The need for routine consultant involvement and critical care is evident, and the case distribution helps define the surgical skill set needed for a modern emergency laparotomy service. Preliminary data relating outcomes from emergency colonic surgery to surgical subspecialty require urgent further study.

Successful radiofrequency ablation of an anterior abdominal wall desmoid in familial adenomatous polyposis.

BACKGROUND: Desmoid tumours are an important cause of mortality in familial adenomatous polyposis (FAP). There are few effective treatment strategies. This report describes the use of radiofrequency ablation to debulk and palliate an abdominal wall desmoid tumour in FAP. METHODS: A 22 year old woman with FAP developed a large abdominal wall desmoid tumour after restorative proctocolectomy. The tumour was treated with 16 separate radiofrequency ablations. The follow up was 36 months from the first ablation. RESULTS: The procedure was well tolerated with minor complications; mild superficial cellulitis and skin ulceration occurred following only one of the ablation sessions. Repeated radiofrequency treatments resulted in a sustained reduction in size and symptoms from the desmoid tumour. CONCLUSION: Given the low efficacy of treatments for desmoids in FAP, radiofrequency ablation appears to be a promising modality.

Colorectal complications of end-stage renal failure and renal transplantation: a review.

AIM: End-stage renal failure (ESRF) and renal transplant recipients are thought to be associated with an increased risk of colorectal complications. METHOD: A review of the literature was performed to assess the prevalence and outcome in both benign and malignant colorectal disease. RESULTS: No prospective randomized studies assessing colorectal complications in ESRF or renal transplant were identified. Case series and case reports have described the incidence and management of benign colorectal complications. Complications included diverticulitis,infective colitis, colonic bleeding and colonic perforation. There was insufficient evidence to associated iverticular disease with adult polycystic kidney disease.Three population-based studies have shown up to a twofold increased incidence of colonic cancer but not rectal cancer for renal transplant recipients. Bowel cancer screening (as per the general population) by faecal occult blood testing appears justified for renal transplant patients; however, evidence suggests that consideration of starting screening at a younger age may be worthwhile because of an increased risk of developing colonic cancer.Two population-based studies have shown a threefold and 10-fold increased incidence of anal cancer for renal transplant recipients. A single case­control study demonstrated significant increased prevalence of anal human papilloma virus (HPV) and intraepithelial neoplasia (AIN)in patients with established renal transplants. CONCLUSIONS: Despite the lack of high-level evidence,ESRF and renal transplantation were associated with colorectal complications that could result in major morbidity and mortality. Bowel cancer screening in this patient group appears justified. The effectiveness of screening for HPV, AIN and anal cancer in renal transplant recipients remains unclear.

Inhibition of antibiotic-resistant Staphylococcus aureus by the broad-spectrum dihydrofolate reductase inhibitor RAB1.

The bacterial burden on human health is quickly outweighing available therapeutics. Our long-term goal is the development of antimicrobials with the potential for broad-spectrum activity. We previously reported phthalazine-based inhibitors of dihydrofolate reductase (DHFR) with potent activity against Bacillus anthracis, a major component of Project BioShield. The most active molecule, named RAB1, performs well in vitro and, in a cocrystal structure, was found deep within the active site of B. anthracis DHFR. We have now examined the activity of RAB1 against a panel of bacteria relevant to human health and found broad-spectrum applicability, particularly with regard to gram-positive organisms. RAB1 was most effective against Staphylococcus aureus, including methicillin- and vancomycin-resistant (MRSA/VRSA) strains. We have determined the cocrystal structure of the wild-type and trimethoprim-resistant (Phe 98 Tyr) DHFR enzyme from S. aureus with RAB1, and we found that rotational freedom of the acryloyl linker region allows the phthalazine moiety to occupy two conformations. This freedom in placement also allows either enantiomer of RAB1 to bind to S. aureus, in contrast to the specificity of B. anthracis for the S-enantiomer. Additionally, one of the conformations of RAB1 defines a unique surface cavity that increases the strength of interaction with S. aureus. These observations provide insights into the binding capacity of S. aureus DHFR and highlight atypical features critical for future exploitation in drug development.

Cumulative lifetime incidence of extracolonic cancers in Lynch syndrome: a report of 121 families with proven mutations.

Lynch syndrome or hereditary non-polyposis colorectal cancer is caused by mutations of DNA mismatch repair (MMR) genes. The extracolonic tumour spectrum includes endometrial, ovarian, gastric, small bowel, pancreatic, hepatobiliary, brain, and urothelial neoplasms. Families were referred on the basis of clinical criteria. Tumour immunohistochemistry and microsatellite testing were performed. Appropriate patients underwent sequencing of relevant exons of the MMR genes. Proven and obligate mutation carriers and first-degree relatives (FDRs) with a Lynch syndrome spectrum cancer were considered mutation carriers, as were a proportion of untested, unaffected FDRs based on the proportion of unaffected relatives testing positive in each age group. Kaplan-Meier analysis of risk to 70 years was calculated. One hundred and eighty-four Lynch syndrome spectrum extracolonic cancers in 839 proven, obligate, or assumed mutation carriers were analysed. Cumulative risk for females of an extracolonic tumour is 47.4% (95% CI 43.9-50.8). The risk to males is 26.5% (95% CI 22.6-30.4). There was no reduction in gynaecological malignancies due to gynaecological screening (examination, transvaginal ultrasound scan, hysteroscopy and endometrial biopsy). Males have a higher risk of gastric cancer than females (p = 0.0003). Gastric cancer risk in those born after 1935 does not justify surveillance. These penetrance estimates have been corrected for ascertainment bias and are appropriate for those referred to a high-risk clinic.

Quantum dots light up pathology.

Quantum dots (QDs) are novel nanocrystal fluorophores with extremely high fluorescence efficiency and minimal photobleaching. They also possess a constant excitation wavelength together with sharp and symmetrical tunable emission spectra. These unique optical properties make them near-perfect fluorescent markers and there has recently been rapid development of their use for bioimaging. QDs can be conjugated to a wide range of biological targets, including proteins, antibodies, and nucleic acid probes, rendering them of particular interest to pathology researchers. They have been used in multiplex immunohistochemistry and in situ hybridization, which when combined with multispectral imaging, has enabled quantitative measurement of gene expression in situ. QDs have also been used for live in vivo animal imaging and are now being applied to an ever-increasing range of biological problems. These are detailed in this review, which also acts to outline the important advances that have been made in their range of applications. The relative novelty of QDs can present problems in their practical use and guidelines for their application are given.

Colorectal cancer in HNPCC: cumulative lifetime incidence, survival and tumour distribution. A report of 121 families with proven mutations.

Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal dominant condition caused by inactivating mutations of DNA mismatch repair (MMR) genes. An accurate estimation of colorectal cancer risk for mutation carriers is essential for counselling and rationalizing screening programmes. Families were referred on the basis of clinical criteria. Tumour immunohistochemistry and microsatellite testing were performed. Appropriate patients underwent sequencing of all relevant exons of the MMR genes. Proven and obligate mutation carriers and first-degree relatives (FDRs) with an HNPCC spectrum cancer were considered mutation carriers, as were a proportion of untested, unaffected FDRs based on the proportion of unaffected relatives testing positive in each age group. The cumulative lifetime risk was calculated by Kaplan-Meier analysis. Three hundred and forty-one colorectal cancers in 839 proven, obligate, or assumed mutation carriers were analysed. The cumulative risk to age 70 years for all mutation carriers combined was 50.4% (95% CI 47.8-52.9). The cumulative risk in males was 54.3% (95% CI 50.7-57.8), which was significantly higher than in females (log rank p = 0.02) who had a risk of 46.3% (95% CI 42.8-49.9). These penetrance estimates from HNPCC families attending high-risk clinics have been corrected for ascertainment bias and are appropriate risks for those referred to a high-risk clinic. Current colonoscopic screening guidelines are appropriate.

Cost analysis of biomarker testing for mismatch repair deficiency in node-positive colorectal cancer.

BACKGROUND: Microsatellite instability (MSI) in colorectal cancer is caused by defective DNA mismatch repair (MMR). It is present in 15 per cent of sporadic colorectal cancers owing to epigenetic mutL homologue 1 (MLH1) inactivation. The evidence suggests that patients with tumours caused by defective DNA MMR do not benefit from 5-fluorouracil (5-FU)-based chemotherapy. METHODS: The proportion of cancers with defective DNA MMR identified by MSI analysis or immunohistochemistry was calculated from published data. The cost of analysis was compared with the potential savings if 5-FU-based chemotherapy was not administered to these patients. RESULTS: Some 16.3 per cent of sporadic colorectal cancers had defective DNA MMR. Immunostaining for MLH1 and mutS homologue 2 (MSH2) had a sensitivity of 92.4 per cent and a specificity of 99.6 per cent for identifying MSI-high tumours. The strongest predictive variable was right-sidedness, with positive and negative predictive values of 0.329 and 0.948 respectively. If 5-FU-based chemotherapy were not administered, potential savings of up to pound 1.2 million per 1000 patients tested could be made. Costs would be higher if alternative chemotherapeutic regimens were substituted as a result of testing. CONCLUSION: Knowledge of MMR status may enable participation in trials of non-5-FU-based chemotherapy. The cost of MMR testing may be offset by more efficient use of chemotherapy.

Children's understanding of mental illness: an exploratory study.

BACKGROUND: This study aimed to investigate children's thinking about mental illness by employing a well-established framework of adult illness understanding. METHODS: The study adopted a semistructured interview technique and a card selection task to assess children's responses to causes, consequences, timeline and curability of the different types of mental illness. The children were aged between 5 and 11 years. RESULTS: Results indicated a developmental trend in the children's thinking about mental illness; there was an increase in the children's understanding of the causes, consequences, curability and timeline of mental illness with age. The older children demonstrated a more sophisticated and accurate thinking about mental illness compared with the younger children, who tended to rely on a medical model in order to comprehend novel mental illnesses. Furthermore, the girls exhibited more compassion, showing greater social acceptance compared with the boys. CONCLUSIONS: The Leventhal model provides a useful framework within which to investigate children's knowledge and understanding of mental illness. Limitations of the study and implications for future research are discussed.

Endoscopically placed caecostomy buttons: a trial ACE procedure.

The use of the antegrade continence enema (ACE) is becoming more widespread. Preliminary studies have been promising, but the procedure is not universally successful. A colonoscopic insertion of a caecostomy button is a relatively minor procedure. This allows the ACE to be used for a trial period to assess whether a permanent procedure would be beneficial. If successful, enemas can be continued by the caecostomy, or a formal ACE can be performed. We report a series of five patients who underwent staged endoscopic insertion of a MIC-KEY caecostomy button, and we discuss the technical aspects of the procedure.

New antifolate inhibitors for Mycobacterium avium.

The present study extends our previous work regarding new antifolates for Mycobacterium avium (MAC) dihydrofolate reductase (DHFR). The objectives of this study were to synthesize and test new derivatives in the general class of 2,4-diamino-5-methyl-5-deazapteridines in an effort to improve solubility and selectivity for the MAC DHFR, while maintaining lack of selectivity for the human DHFR. New 6-[2', 5'-dialkoxyphenyl) methyl]-substituted DMDP analogs were synthesized as previously described. Three clinical isolates of MAC (NJ211, NJ3404, and NJ168) and M. tuberculosis H37Ra (MTB) were used to evaluate the new derivatives. A previously described colorimetric (alamarBlue(R)) microdilution broth assay was used to determine minimal inhibitory concentrations (MIC). Purified recombinant human (rDHFR), MAC rDHFR, and MTB rDHFR were used in a validated enzyme assay to obtain IC(50) values and to determine selectivity ratios (SR) for the derivatives. For the MAC strains, the MICs ranged from < 0.25 to > 16 microg/mL. The most active derivative against MAC was SRI-20920 which had MICs of 0.25, 0.25, and 8 microg/mL for the three strains, respectively. The most selective derivative was SRI-20730 with IC(50s) of 29 and 67,781 nM for MAC rDHFR and hDHFR, respectively, and a SR of 2,337. MICs for MTB ranged from 4 to >64 microg/mL and the SR, in general, ranged from 0.32 to 2.5. These results further substantiate the utility of this group of DMDP derivatives for selective activity against MAC.

Treatment of tuberculosis using a combination of sustained-release rifampin-loaded microspheres and oral dosing with isoniazid.

Previously, we reported on the use of rifampin-loaded microspheres to effectively treat Mycobacterium tuberculosis-infected macrophages and mice. Using similar biocompatible polymeric excipients of lactide and glycolide copolymers, we have increased the rifampin loading of small microsphere formulations (1 to 10 microm) by fourfold. Improved formulations were evaluated individually and in combination with oral regimens of isoniazid for the treatment of Mycobacterium tuberculosis H37Rv-infected mice. Groups (10 mice per group) consisted of mice that received (i) oral dosages of isoniazid (25 to 0.19 mg/kg of body weight/day), (ii) two intraperitoneal injections of rifampin-loaded microspheres on days 0 and 7, (iii) a combination of small rifampin-loaded microspheres on days 0 and 7 and isoniazid orally for 25 days (12.5 to 0.39 mg/kg/day), (iv) placebo injections, and (v) no treatment. Treatment with rifampin-loaded microspheres alone resulted in significant reductions in the numbers of CFU in the lungs and spleens by day 26. A bioassay revealed that plasma rifampin levels from the microspheres exceeded the MICs by more than twofold throughout the 26-day experimental period. Susceptibility testing demonstrated continued sensitivity to rifampin during the treatment period. Whereas isoniazid alone significantly reduced the numbers of CFU for dosages ranging from 12.5 to 1.56 mg/kg, combination therapy with rifampin-loaded microspheres increased the effective range to 0.39 mg/kg. In many cases, complete elimination of CFU was obtained with the combination therapy, something not achieved with most of the single therapies. These results demonstrate the ability to use small microsphere formulations alone to achieve significant results in a murine tuberculosis model and also the ability to use them safely in combination with another antimycobacterial agent.

Antimycobacterial activities of 2,4-diamino-5-deazapteridine derivatives and effects on mycobacterial dihydrofolate reductase.

Development of new antimycobacterial agents for Mycobacterium avium complex (MAC) infections is important particularly for persons coinfected with human immunodeficiency virus. The objectives of this study were to evaluate the in vitro activity of 2, 4-diamino-5-methyl-5-deazapteridines (DMDPs) against MAC and to assess their activities against MAC dihydrofolate reductase recombinant enzyme (rDHFR). Seventy-seven DMDP derivatives were evaluated initially for in vitro activity against one to three strains of MAC (NJ168, NJ211, and/or NJ3404). MICs were determined with 10-fold dilutions of drug and a colorimetric (Alamar Blue) microdilution broth assay. MAC rDHFR 50% inhibitory concentrations versus those of human rDHFR were also determined. Substitutions at position 5 of the pteridine moiety included -CH(3), -CH(2)CH(3), and -CH(2)OCH(3) groups. Additionally, different substituted and unsubstituted aryl groups were linked at position 6 through a two-atom bridge of either -CH(2)NH, -CH(2)N(CH(3)), -CH(2)CH(2), or -CH(2)S. All but 4 of the 77 derivatives were active against MAC NJ168 at concentrations of < or =13 microg/ml. Depending on the MAC strain used, 81 to 87% had MICs of < or =1.3 microg/ml. Twenty-one derivatives were >100-fold more active against MAC rDHFR than against human rDHFR. In general, selectivity was dependent on the composition of the two-atom bridge at position 6 and the attached aryl group with substitutions at the 2' and 5' positions on the phenyl ring. Using this assessment, a rational synthetic approach was implemented that resulted in a DMDP derivative that had significant intracellular activity against a MAC-infected Mono Mac 6 monocytic cell line. These results demonstrate that it is possible to synthesize pteridine derivatives that have selective activity against MAC.

Exposure of human peripheral blood mononuclear cells to total lipids and serovar-specific glycopeptidolipids from Mycobacterium avium serovars 4 and 8 results in inhibition of TH1-type responses.

Previous studies have suggested that large quantities of bacterial lipids may accumulate and persist within host cells during chronic stages of Mycobacterium avium infections. This study intended to assess the ability of purified M. avium lipids to affect TH-1-type responses in human peripheral blood mononuclear cells (PBMC) from healthy donors. PBMC were exposed to total lipids and serovar-specific glycopeptidolipids (GPL) extracted from M. avium serovars 4 and 8, which have been reported to predominate as opportunistic infection among AIDS patients. After 24 h exposure to lipids followed by PHA/PMA treatment, IL-2 and IFN-gamma were assayed in the supernatants. Reverse transcriptase polymerase chain reaction (RT-PCR) was used for a semiquantitative estimation of mRNA for IL-2 and IFN-gamma in cell pellets at various time points. Exposure of PBMC to M. avium total lipids significantly suppressed PHA/PMA-induced secretion of IL-2 and IFN-gamma as determined by ELISA. The GPL antigens from serovar 4 were more efficient at inhibiting TH-1 responses than GPL from serovar 8. CD4(+)T-lymphocyte enrichment of PBMC demonstrated that suppression by M. avium lipids was intact without the presence of other cell populations such as monocytes and B-cells. Preliminary RT-PCR experiments showed that the secretion of TH-1 cytokines was partially affected at the transcriptional level. The results obtained showed that M. avium lipids are indeed able to modify the induction of TH-1-type cytokines by human PBMC, and suggest that accumulation of M. avium lipids in the chronic stages of infection may play an important role in the pathogenesis of HIV infection.

Efficacy of microencapsulated rifampin in Mycobacterium tuberculosis-infected mice.

Rifampin is a first-line drug useful in the treatment of tuberculosis. By using biocompatible polymeric excipients of lactide and glycolide copolymers, two microsphere formulations were developed for targeted and sustained delivery of rifampin, with minimal dosing. A small-microsphere formulation, with demonstrated ability to inhibit intracellularly replicating Mycobacterium tuberculosis H37Rv, was tested along with a large-microsphere formulation in an infected mouse model. Results revealed that by using a single treatment of the large-microsphere formulation, it was possible to achieve a significant reduction in M. tuberculosis H37Rv CFUs in the lungs of mice by 26 days postinfection. A combination of small (given as two injections on day 0 and day 7) and large (given as one injection at day 0) rifampin-loaded microsphere formulations resulted in significant reductions in CFUs in the lungs by 26 days, achieving a 1.23 log10 reduction in CFUs. By comparison, oral treatment with 5, 10, or 20 mg of rifampin/kg of body weight, administered every day, resulted in a reduction of 0.42, 1.7, or 1.8 log10 units, respectively. Thus the microsphere formulations, administered in one or two doses, were able to achieve results in mice similar to those obtained with a daily drug regimen within the range of the highest clinically tolerated dosage in humans. These results demonstrate that microsphere formulations of antimycobacterial drugs such as rifampin can be used for therapy of tuberculosis with minimal dosing.