Communication and building social capital in community supported agriculture.

Community supported agriculture (CSA) schemes (programs) provide an alternative means for obtaining produce, through direct purchase from farms. They are also often driven by a vision of transforming the current mainstream food system and seek to build a community of people who support this vision. Social capital refers to the networks and ties between people and groups and the impact of these ties on access to influence, information, opportunity, and ability to organize. Social capital is built by CSAs and helps foster and stabilize the grassroots agricultural innovations that are needed for the development of sustainable food systems. Using the concept of social capital, we studied communication methods of four CSAs in the UK, examining the interactions between CSAs and their members and within each of their membership groups. We carried out in-depth interviews with 49 CSA members to establish what interactions they had with their CSA and with other members, and analyzed our data thematically to identify the characteristics of interactions that were important to participants. We consider how our research may benefit CSA organizations by enabling them to learn what their members want and to learn about the varied ways in which members conceptualize their experiences of community derived from their membership. We found that the various CSA communication strategies, which consist of frequent and varying virtual and face-to-face interactions, are able to promote development of both bridging and bonding social capital. Overall, there is a desire for social connection in CSA memberships. Furthermore, in CSAs where members can interact easily, there is potential for CSA membership to provide members with communication that is important as a source of both knowledge and social connection. CSAs can maximize both social capital and member satisfaction by using a range of communication media and methods to meet their members' circumstances and preferences.

Phenotypic and functional characterization of endothelial colony forming cells derived from human umbilical cord blood.

Longstanding views of new blood vessel formation via angiogenesis, vasculogenesis, and arteriogenesis have been recently reviewed. The presence of circulating endothelial progenitor cells (EPCs) were first identified in adult human peripheral blood by Asahara et al. in 1997 bringing an infusion of new hypotheses and strategies for vascular regeneration and repair. EPCs are rare but normal components of circulating blood that home to sites of blood vessel formation or vascular remodeling, and facilitate either postnatal vasculogenesis, angiogenesis, or arteriogenesis largely via paracrine stimulation of existing vessel wall derived cells. No specific marker to identify an EPC has been identified, and at present the state of the field is to understand that numerous cell types including proangiogenic hematopoietic stem and progenitor cells, circulating angiogenic cells, Tie2+ monocytes, myeloid progenitor cells, tumor associated macrophages, and M2 activated macrophages participate in stimulating the angiogenic process in a variety of preclinical animal model systems and in human subjects in numerous disease states. Endothelial colony forming cells (ECFCs) are rare circulating viable endothelial cells characterized by robust clonal proliferative potential, secondary and tertiary colony forming ability upon replating, and ability to form intrinsic in vivo vessels upon transplantation into immunodeficient mice. While ECFCs have been successfully isolated from the peripheral blood of healthy adult subjects, umbilical cord blood (CB) of healthy newborn infants, and vessel wall of numerous human arterial and venous vessels. CB possesses the highest frequency of ECFCs that display the most robust clonal proliferative potential and form durable and functional blood vessels in vivo. While the derivation of ECFC from adult peripheral blood has been presented, here we describe the methodologies for the derivation, cloning, expansion, and in vitro as well as in vivo characterization of ECFCs from the human umbilical CB.

Biomarker responses and disease susceptibility in juvenile rainbow trout Oncorhynchus mykiss fed a high molecular weight PAH mixture.

Juvenile rainbow trout were fed a diet containing an environmentally relevant mixture of 10 high molecular weight polycyclic aromatic hydrocarbons (PAHs) at a dose of 0.66 or 7.82 µg PAH · g fish(-1) · d(-1). At 3, 7, 14, and 28 d, biomarkers of aryl hydrocarbon receptor activation (AHR), hepatic microsomal ethoxyresorufin-O-deethylase (EROD) activity, and cytochrome P4501A (CYP1A)-associated staining increased 14- to 26-fold and 6- to 14-fold, respectively, in fish fed 7.82 µg PAH · g fish (-1) · d(-1). Cytochrome P4501A-associated staining increased 2- to 9-fold on days 3, 7, and 28 in fish fed 0.66 µg PAH · g fish(-1) · d(-1). Bile fluorescent aromatic compounds served as a biomarker of exposure and confirmed that PAH exposure was consistent over 50 d. DNA damage in blood cells, protein oxidation, and lipid peroxidation in the kidney were biomarkers of oxidative stress and all increased in fish fed 7.82 µg PAH · g fish(-1) · d(-1). Fish fed 0.66 µg PAH · g fish(-1) · d(-1) had elevated DNA damage in blood cells but increased protein oxidation or lipid peroxidation in the kidney were not observed. Challenge with Aeromonas salmonicida, at lethal concentration (LC) 20, decreased survival in fish previously fed either 0.66 µg PAH · g fish(-1) · d(-1) or 7.82 µg PAH · g fish(-1) · d(-1) relative to fish fed the control diet. In general, biomarkers of both AHR activation and oxidative stress peaked at 3 to 14 d then declined at 28 to 50 d of PAH exposure and an increase in susceptibility to disease was observed at 50 d. These results link PAH exposure to biomarker responses that may be useful as early indicators of population level responses, such as mortality resulting from an increase in disease susceptibility.

Advancing environmental toxicology through chemical dosimetry: external exposures versus tissue residues.

The tissue residue dose concept has been used, although in a limited manner, in environmental toxicology for more than 100 y. This review outlines the history of this approach and the technical background for organic chemicals and metals. Although the toxicity of both can be explained in tissue residue terms, the relationship between external exposure concentration, body and/or tissues dose surrogates, and the effective internal dose at the sites of toxic action tends to be more complex for metals. Various issues and current limitations related to research and regulatory applications are also examined. It is clear that the tissue residue approach (TRA) should be an integral component in future efforts to enhance the generation, understanding, and utility of toxicity testing data, both in the laboratory and in the field. To accomplish these goals, several key areas need to be addressed: 1) development of a risk-based interpretive framework linking toxicology and ecology at multiple levels of biological organization and incorporating organism-based dose metrics; 2) a broadly applicable, generally accepted classification scheme for modes/mechanisms of toxic action with explicit consideration of residue information to improve both single chemical and mixture toxicity data interpretation and regulatory risk assessment; 3) toxicity testing protocols updated to ensure collection of adequate residue information, along with toxicokinetics and toxicodynamics information, based on explicitly defined toxicological models accompanied by toxicological model validation; 4) continued development of residue-effect databases is needed ensure their ongoing utility; and 5) regulatory guidance incorporating residue-based testing and interpretation approaches, essential in various jurisdictions.

Histone H2AX is a critical factor for cellular protection against DNA alkylating agents.

Histone H2A variant H2AX is a dose-dependent suppressor of oncogenic chromosome translocations. H2AX participates in DNA double-strand break repair, but its role in other DNA repair pathways is not known. In this study, role of H2AX in cellular response to alkylation DNA damage was investigated. Cellular sensitivity to two monofunctional alkylating agents (methyl methane sulfonate and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)) was dependent on H2AX dosage, and H2AX null cells were more sensitive than heterozygous cells. In contrast to wild-type cells, H2AX-deficient cells displayed extensive apoptotic death due to a lack of cell-cycle arrest at G(2)/M phase. Lack of G(2)/M checkpoint in H2AX null cells correlated well with increased mitotic irregularities involving anaphase bridges and gross chromosomal instability. Observation of elevated poly(ADP) ribose polymerase 1 (PARP-1) cleavage suggests that MNNG-induced apoptosis occurs by PARP-1-dependent manner in H2AX-deficient cells. Consistent with this, increased activities of PARP and poly(ADP) ribose (PAR) polymer synthesis were detected in both H2AX heterozygous and null cells. Further, we demonstrate that the increased PAR synthesis and apoptotic death induced by MNNG in H2AX-deficient cells are due to impaired activation of mitogen-activated protein kinase pathway. Collectively, our novel study demonstrates that H2AX, similar to PARP-1, confers cellular protection against alkylation-induced DNA damage. Therefore, targeting either PARP-1 or histone H2AX may provide an effective way of maximizing the chemotherapeutic value of alkylating agents for cancer treatment.

Chromosome aberrations induced by dual exposure of protons and iron ions.

During space travel, astronauts will be exposed to protons and heavy charged particles. Since the proton flux is high compared to HZE particles, on average, it is assumed that a cell will be hit by a proton before it is hit by an HZE ion. Although the effects of individual ion species on human cells have been investigated extensively, little is known about the effects of exposure to mixed beam irradiation. To address this, we exposed human epithelial cells to protons followed by HZE particles and analyzed chromosomal damage using the multicolor banding in situ hybridization (mBAND) procedure. With this technique, individually painted chromosomal bands on one chromosome allowed the identification of intra-chromosomal aberrations (inversions and deletions within a single painted chromosome) as well as inter-chromosomal aberrations (translocation to unpainted chromosomes). Our results indicated that chromosome aberration frequencies from exposures to protons followed by Fe ions did not simply decrease as the interval between the two exposures increased, but peak when the interval was 30 min.

Induction of micronuclei in human fibroblasts across the Bragg curve of energetic heavy ions.

The space environment consists of a varying field of radiation particles including high-energy ions, with spacecraft shielding material providing the major protection to astronauts from harmful exposure. Unlike low-LEpsilonTau gamma or X rays, the presence of shielding does not always reduce the radiation risks for energetic charged-particle exposure. The dose delivered by the charged particle increases sharply as the particle approaches the end of its range, a position known as the Bragg peak. However, the Bragg curve does not necessarily represent the biological damage along the particle path since biological effects are influenced by the track structures of both primary and secondary particles. Therefore, the "biological Bragg curve" is dependent on the energy and the type of the primary particle and may vary for different biological end points. Here we report measurements of the biological response across the Bragg curve in human fibroblasts exposed to energetic silicon and iron ions in vitro at two different energies, 300 MeV/nucleon and 1 GeV/nucleon. A quantitative biological response curve generated for micronuclei per binucleated cell across the Bragg curve did not reveal an increased yield of micronuclei at the location of the Bragg peak. However, the ratio of mono- to binucleated cells, which indicates inhibition of cell progression, increased at the Bragg peak location. These results confirm the hypothesis that severely damaged cells at the Bragg peak are more likely to go through reproductive death and not be evaluated for micronuclei.

Postoperative complications are not increased in super-super obese patients who undergo laparoscopic Roux-en-Y gastric bypass.

BACKGROUND: It has been suggested that super-super obesity (body mass index [BMI] > or =60 kg/m2) increases the risk of complications after laparoscopic Roux-en-Y gastric bypass (LapRYGB). We hypothesized that a higher BMI does not increase risk the morbidity or mortality rate. METHODS: Complication rates for patients with a BMI > or =60 kg/m2 were compared to those for patients with a BMI <60 kg/m2 who underwent LapRYGB during the same time period. Differences between the groups were analyzed by Fisher's exact test, t-tests, and analysis of variance. RESULTS: Forty-five patients with a BMI > or =60 kg/m2 and 640 patients with a BMI <60 kg/m2 underwent LapRYGB. There were no statistically significant differences between the two groups in the complication or mortality rates. Excess weight loss was less, but actual weight lost was greater in the BMI > or =60 kg/m2 group. CONCLUSIONS: The complication and mortality rates are not increased in super-super obese patients who undergo LapRYGB. Acceptable weight loss can be achieved safely in these patients.

Conservation of amino acids in human rhinovirus 3C protease correlates with broad-spectrum antiviral activity of rupintrivir, a novel human rhinovirus 3C protease inhibitor.

The picornavirus 3C protease is required for the majority of proteolytic cleavages that occur during the viral life cycle. Comparisons of published amino acid sequences from 6 human rhinoviruses (HRV) and 20 human enteroviruses (HEV) show considerable variability in the 3C protease-coding region but strict conservation of the catalytic triad residues. Rupintrivir (formerly AG7088) is an irreversible inhibitor of HRV 3C protease with potent in vitro activity against all HRV serotypes (48 of 48), HEV strains (4 of 4), and untyped HRV field isolates (46 of 46) tested. To better understand the relationship between in vitro antiviral activity and 3C protease-rupintrivir binding interactions, we performed nucleotide sequence analyses on an additional 21 HRV serotypes and 11 HRV clinical isolates. Antiviral activity was also determined for 23 HRV clinical isolates and four additional HEV strains. Sequence comparison of 3C proteases (n = 58) show that 13 and 11 of the 14 amino acids that are involved in side chain interactions with rupintrivir are strictly conserved among HRV and HEV, respectively. These sequence analyses are consistent with the comparable in vitro antiviral potencies of rupintrivir against all HRV serotypes, HRV isolates, and HEV strains tested (50% effective concentration range, 3 to 183 nM; n = 125). In summary, the conservation of critical amino acid residues in 3C protease and the observation of potent, broad-spectrum antipicornavirus activity of rupintrivir highlight the advantages of 3C protease as an antiviral target.

Experience with over 3,000 open and laparoscopic bariatric procedures: multivariate analysis of factors related to leak and resultant mortality.

BACKGROUND: Intestinal leak is a potentially lethal complication of Roux en-Y gastric bypass (GBP). Identification of patients at high risk for leak may reduce complication rates of surgeons early in the procedure learning curve. METHODS: A total of 3073 patients who underwent GBP were analyzed using univariate and multivariate logistic regression analyses of the following preoperative factors: hypertension (HTN), diabetes mellitus (DM), sleep apnea (SA), age, gender, weight, body mass index (BMI), and surgery type. Multivariate logistic regression analysis was performed for each procedure type. RESULTS: There were 48 (1.5%) deaths. Independent risk factors for death included leak, weight, procedure type, and HTN. A total of 102 (3.2%) leaks were found. Independent factors for leak included age, male gender, SA, and procedure type. CONCLUSION: The data suggests that older, heavier male patients with multiple comorbid conditions are at increased risk for leak and mortality. Surgeons early in their learning curve should avoid these high-risk patients to reduce complications.

Hand-assisted laparoscopic gastric bypass does not improve outcome and increases costs when compared to open gastric bypass for the surgical treatment of obesity.

BACKGROUND: Hand-assisted laparoscopic Roux-en-Y gastric bypass (Hand-Lap GB) has been adopted by some surgeons to treat morbid obesity because it is easier to perform than the total laparoscopic procedure, but to date no study has compared the outcomes of patients undergoing the Hand-Lap GB to those obtained with the open procedure (Open GB). We hypothesized that patients undergoing Hand-Lap GB would lose a similar amount of weight when compared to Open GB patients, while experiencing no increase in complications, a shorter hospital stay, and lower overall costs of care, in part as a result of fewer incisional hernias requiring subsequent surgery. METHODS: Nonrandomized, prospective data were collected on all patients undergoing proximal GB via Hand-Lap or open approaches between May 1998 and July 1999. Our first 25 Hand-Lap GB procedures, performed in selected patients (with no extensive previous abdominal surgery) referred to two of us (E.J.D, M.A.S), were compared to all other (n = 62) concurrent open proximal GB performed by the group during this period of time in patients with body mass index (BMI) <50 kg/m2. RESULTS: Preoperatively, Hand-Lap GB patients did not differ from Open GB patients in age (40 +/- 11 vs 43 +/- 11 years), gender (92% female vs 81% female), incidence or type of preoperative comorbid conditions, preoperative weight (282 +/- 33 vs 280 +/- 37 lb), or BMI (45.5 +/- 5.4 vs 44.1 +/- 3.3 kg/m2). (Data given as mean +/- standard deviation). Although length of hospital stay did not differ between groups (3.6 +/- 1.3 vs 4.2 +/- 4.6 days), total hospital costs were significantly higher for Hand-Lap GB ($14,725 +/- 3089 vs. $10,281 +/- 3687, p <0.01 ANOVA). One patient in the Open GB group developed an anastomotic leak from the gastrojejunostomy. Follow-up revealed that Hand-Lap GB patients had a similar risk of postoperative complications as the Open GB group, including marginal ulcer (16% vs 14.5%), stomal stenosis (24% vs 23%), and, most notably, incisional hernia (20% vs 27%). There were no major wound infections or deaths in either group. One patient in each group developed a postoperative small bowel obstruction. Loss of excess weight in Hand-Lap GB patients at 12 months postoperatively was 66 +/- 14% vs 77 +/- 14% in the Open GB group. CONCLUSIONS: The Hand-Lap GB yielded good weight reduction in a population of morbidly obese patients, but at a higher cost for hospital care than Open GB. There was no decrease in the incidence of incisional hernias with the Hand-Lap GB procedure. Although Hand-Lap GB appears to be safe and effective, its failure to provide a decrease in hospital stay or risk of incisional hernia requiring subsequent surgical repair is significant. The primary role for the Hand-Lap GB procedure should therefore be to aid surgeons in developing skills to climb the steep learning curve for total laparoscopic gastric bypass, since Hand-Lap GB does not improve patient outcome and increases cost in comparison to the open GB procedure.

Design and synthesis of irreversible depsipeptidyl human rhinovirus 3C protease inhibitors.

Novel tripeptidyl C-terminal Michael acceptors with an ester replacement of the P(2)-P(3) amide bond were investigated as irreversible inhibitors of the human rhinovirus (HRV) 3C protease (3CP). When screened against HRV serotype-14 the best compound was shown to have very good 3CP inhibition (k(obs)/[I]=270,000M(-1)s(-1)) and potent in vitro antiviral activity (EC(50)=7.0nM).

Impaired growth in the polychaete Armandia brevis exposed to tributyltin in sediment.

Juveniles of the opheliid polychaete, Armandia brevis, were exposed to sediment-associated tributyltin (TBT) for 42 days to evaluate toxicity and bioaccumulation. Growth in this species was inhibited in a dose-response fashion by increasing concentrations of TBT. Even though the biota-sediment accumulation factor (BSAF) for TBT declined for the higher sediment concentrations, the total butyltins in tissue increased over all sediment concentrations. At the highest sediment concentrations, polychaetes bioaccumulated less TBT than expected, which was most likely due to reduced uptake and continued metabolism of the parent compound. The less than expected BSAF values exhibited by animals at the exposure concentrations causing severe effects are an important finding for assessing responses in the field. It appears that severe biological effects can occur in long-term experiments without the expected high tissue concentrations; an observation likely explained by altered toxicokinetics. Analysis of variance determined the lowest observed effect concentration for growth to be 191 ng/g sediment dry wt. for 21 days of exposure and 101 ng/g sediment dry wt. at day 42, indicating that 21 days was insufficient for delineating the steady-state toxicity response. When based on regression analysis, the sediment concentration causing a 25% inhibition in growth at 42 days exposure was 93 ng/g dry wt. (total organic carbon = 0.58%). A dose-response association was also determined for polychaete net weight and TBT in tissue. The tissue residue associated with a 25% reduction in growth was 2834 ng/g dry wt. at day 42. A comparison of these results with previous work indicates that juveniles are approximately three times more sensitive than adults to TBT exposure. The sediment concentrations affecting growth in this species are commonly found in urban waterways indicating potentially severe impacts for this and other sensitive species.

Rapid multiserotype detection of human rhinoviruses on optically coated silicon surfaces.

BACKGROUND: More than 100 immunologically distinct serotypes of human rhinoviruses (HRV) have been discovered, making detection of surface exposed capsid antigens impractical. However, the non-structural protein 3C protease (3Cpro) is essential for viral replication and is relatively highly conserved among serotypes, making it a potential target for diagnostic testing. The thin film biosensor is an assay platform that can be formatted into a sensitive immunoassay for viral proteins in clinical specimens. The technology utilizes an optically coated silicon surface to convert specific molecular binding events into visual color changes by altering the reflective properties of light through molecular thin films. OBJECTIVE: To develop a rapid test for detection of HRV by developing broadly serotype reactive antibodies to 3Cpro and utilizing them in the thin film biosensor format. STUDY DESIGN: Polyclonal antibodies to 3Cpro were purified and incorporated into the thin film assay. The in vitro sensitivity, specificity and multiserotype cross-reactivity of the 3Cpro assay were tested. Nasal washes from naturally infected individuals were also tested to verify that 3Cpro was detectable in clinical specimens. RESULTS: The 3Cpro assay is a 28-min, non-instrumented room temperature test with a visual limit of detection of 12 pM (picomolar) 3Cpro. In terms of viral titer, as few as 1000 TCID(50) equivalents of HRV2 were detectable. The assay detected 45/52 (87%) of the HRV serotypes tested but showed no cross-reactivity to common respiratory viruses or bacteria. The thin film assay detected 3Cpro in HRV-infected cell culture supernatants coincident with first appearance of cytopathic effect. Data are also presented demonstrating 3Cpro detection from clinical samples collected from HRV-infected individuals. The assay detected 3Cpro in expelled nasal secretions from a symptomatic individual on the first day of illness. In addition, 9/11 (82%) concentrated nasal wash specimens from HRV infected children were positive in the 3Cpro test. CONCLUSION: We have described a novel, sensitive thin film biosensor for rapid detection of HRV 3Cpro. This test may be suitable for the point of care setting, where rapid HRV diagnostic test results could contribute to clinical decisions regarding appropriate antibiotic or antiviral therapy.

High failure rate after laparoscopic adjustable silicone gastric banding for treatment of morbid obesity.

OBJECTIVE: To report the results from one of the eight original U.S. centers performing laparoscopic adjustable silicone gastric banding (LASGB), a new minimally invasive surgical technique for treatment of morbid obesity. SUMMARY BACKGROUND DATA: Laparoscopic adjustable silicone gastric banding is under evaluation by the Food & Drug Administration in the United States in an initial cohort of 300 patients. METHODS: Of 37 patients undergoing laparoscopic placement of the LASGB device, successful placement occurred in 36 from March 1996 to May 1998. Patients have been followed up for up to 4 years. RESULTS: Five patients (14%) have been lost to follow-up for more than 2 years but at last available follow-up (3-18 months after surgery) had achieved only 18% (range 5-38%) excess weight loss. African American patients had poor weight loss after LASGB compared with whites. The LASGB devices were removed in 15 (41%) patients 10 days to 42 months after surgery. Four patients underwent simple removal; 11 were converted to gastric bypass. The most common reason for removal was inadequate weight loss in the presence of a functioning band. The primary reasons for removal in others were infection, leakage from the inflatable silicone ring causing inadequate weight loss, or band slippage. The patients with band slippage had concomitant poor weight loss. Bands were removed in two others as a result of symptoms related to esophageal dilatation. In 18 of 25 patients (71%) who underwent preoperative and long-term postoperative contrast evaluation, a significantly increased esophageal diameter developed; of these, 13 (72%) had prominent dysphagia, vomiting, or reflux symptoms. Of the remaining 21 patients with bands, 8 currently desire removal and conversion to gastric bypass for inadequate weight loss. Six of the remaining patients have persistent morbid obesity at least 2 years after surgery but refuse to undergo further surgery or claim to be satisfied with the results. Overall, only four patients achieved a body-mass index of less than 35 and/or at least a 50% reduction in excess weight. Thus, the overall need for band removal and conversion to GBP in this series will ultimately exceed 50%. CONCLUSIONS: The authors did not find LASGB to be an effective procedure for the surgical treatment of morbid obesity. Complications after LASGB include esophageal dilatation, band leakage, infection, erosion, and slippage. Inadequate weight loss is common, particularly in African American patients. More study is required to determine the long-term efficacy of the LASGB

Resolution of UV-induced DNA damage in Xiphophorus fishes.

The genus Xiphophorus is an important model for investigating the etiology and genetics of sunlight-induced melanoma as well as other cancers. We investigated the role DNA damage plays in tumorigenesis in Xiphophorus using a variety of immunological techniques to examine the induction, distribution, and repair of the major photoproducts in DNA after exposure to solar (ultraviolet-B) radiation. We found that cyclobutane pyrimidine dimers (CPDs) were induced at 5- to 10-fold greater frequency than the (6-4) photoproduct ((6-4)PD) in Xiphophorus signum, and the efficiency of photoproduct formation was tissue-dependent, with the scales providing considerable photoprotection against both types of damage. Both of these lesions are efficiently repaired in the presence of visible light by photoenzymatic repair with CPDs repaired at about twice the rate of (6-4)PDs. Photoenzymatic repair of cyclobutane dimers is inducible by prior exposure to low levels of visible light and can be extremely rapid, with most of the lesions removed within 30 minutes. In the absence of light, dimers are removed by nucleotide excision repair with somewhat greater efficiency for the (6-4)PD compared with the CPD in most species. The relative efficiencies of nucleotide excision repair and photoenzymatic repair are tissue-specific and species-specific. The diverse photochemical and photobiological responses observed in Xiphophorus fishes suggest that heritable traits governing the induction and repair of DNA damage may be involved in the susceptibility of Xiphophorus hybrids to melanomagenesis.

Ileal pouch anal anastomosis without ileal diversion.

OBJECTIVE: To evaluate continued experience with a one-stage stapled ileoanal pouch procedure without temporary ileostomy diversion. SUMMARY BACKGROUND DATA: Most centers perform colectomy, proctectomy, and ileal pouch anal anastomoses (IPAA) with a protective ileostomy. Following a previous report, the authors performed 126 additional stapled IPAA procedures for ulcerative colitis and familial adenomatous polyposis, of which all but 2 were without an ileostomy. Outcomes in these patients question the need for temporary ileal diversion, with its complications and need for subsequent surgical closure. METHODS: Two hundred one patients underwent a stapled IPAA since May 1989, 192 as a one-stage procedure without ileostomy, and 1 with a concurrent Whipple procedure for duodenal adenocarcinoma. Patient charts were reviewed or patients were contacted by phone to evaluate their clinical status at least 1 year after their surgery. RESULTS: Among the patients who underwent the one-stage procedure, 178 had ulcerative colitis (38 fulminant), 5 had Crohn's disease (diagnosed after IPAA), 1 had indeterminate colitis, and 8 had familial adenomatous polyposis. The mean age was 38 +/- 7 (range 7--70) years; there were 98 male patients and 94 female patients. The average amount of diseased tissue between the dentate line and the anastomosis was 0.9 +/- 0.1 cm, with 35% of the anastomoses at the dentate line. With 89% follow-up at 1 year or more (mean 5.1 +/- 2.4 years) after surgery, the average 24-hour stool frequency was 7.1 +/- 3.3, of which 0.9 +/- 1.4 were at night. Daytime stool control was 95% and night-time control was 90%. Only 2.3% needed to wear a perineal pad. Average length of hospital stay was 10 +/- 0.3 days, with 1.5 +/- 0.5 days readmission for complications. Abscesses or enteric leaks occurred in 23 patients; IPAA function was excellent in 19 of these patients (2 have permanent ileostomies). In patients taking steroids, there was no significant difference in leak rate with duration of use (29 +/- 8 with vs. 22 +/- 2 months without leak) or dose (32 +/- 13 mg with vs. 35 +/- 3 mg without leak). Two (1%) patients died (myocardial infarction, mesenteric infarction). CONCLUSIONS: The triple-stapled IPAA without temporary ileal diversion has a relatively low complication rate and a low rate of small bowel obstruction, provides excellent fecal control, permits an early return to a functional life, and can be performed in morbidly obese and older patients.

Induction, distribution and repair of UV photodamage in the platyfish, Xiphophorus signum.

The genus Xiphophorus is an important model for investigating the etiology and genetics of sunlight-induced melanoma as well as other cancers. We used immunological techniques to determine the induction, distribution and repair of cyclobutane pyrimidine dimers (CPD) and pyrimidine(6-4)pyrimidone dimers ([6-4]PD) in different tissues of Xiphophorus signum exposed to ultraviolet-B light. We found that the (6-4)PD was induced at 5 to 10-fold lower frequency than the CPD and that scalation provided considerable photoprotection against both photoproducts. Photoenzymatic repair (PER) was very efficient in X. signum with most of the lesions removed within 20 min; PER of CPD occurred at about twice the rate of (6-4)PD. Nucleotide excision repair (NER) was much less efficient than PER and the rates of CPD and (6-4)PD removal were comparable. PER was more efficient in the caudal fin compared to the lateral epidermis; the opposite was true for NER. Although the initial rate of CPD excision was five-fold faster in the lateral epidermis compared to the caudal fin a considerable amount of residual damage remained in both tissues. The diverse photochemical and photobiological responses observed in X. signum suggest that heritable traits governing deoxyribonucleic acid damage induction and repair may be involved in the susceptibility of other Xiphophorus species to melanomagenesis.

Predicting the fate and effects of tributyltin in marine systems.

The available data indicate that sediment-water partitioning, bioaccumulation, and the toxicity responses for tributyltin (TBT) are predictable when using some of the assumptions and tenets of the equilibrium partitioning method, toxicokinetic modeling (1CFOK), and critical body residue (CBR) approach. Because TBT is ionizable, its speciation is strongly affected by pH, which appears to cause large variations in the octanol-water partition coefficient. In marine systems, and in freshwater systems with high pH, TBT occurs predominantly in the hydroxide form, which may explain the hydrophobic properties and its EqP behavior. Organic carbon in sediment (> 0.2%) appears to be the major controlling factor for sediment-water partitioning. The equilibrium organic carbon-normalized sediment-water partition coefficient (Koc) in marine environments is approximately 32,000 (log10 Koc approximately 4.5), which was determined from direct measurement and confirmed by the relationship between the lipid-normalized bioconcentration factor (BCF) in porewater and the biota-sediment accumulation factor (BSAF). The conclusion that sediment-water partitioning of TBT in marine systems follows EqP is supported by the similarity between its Kow and Koc and the correlation between the sediment-water partition coefficient (Kp) and sediment TOC, which results from the influence of organic carbon on pore-water concentrations. Even though the rates of uptake and elimination control tissue residues and lipid content appears to have no bearing on the amount of TBT that is accumulated, the species specific BSAF is useful for examining bioaccumulation, sediment-water partitioning, and the toxicity response. Although TBT is hydrophobic and appears to have a propensity to accumulate in lipid, the rates of uptake and elimination, not thermodynamics, appear to control whole-body tissue concentrations. Support for a toxicokinetic approach for predicting tissue residues is found in BCF and BSAF values for several species that are far in excess of that predicted by simple thermodynamic partitioning and in the comparisons of observed and predicted bioaccumulation values based on toxicokinetic coefficients. This observation is counter to the assumption of EqP that the route of uptake is of no consequence under equilibrium conditions. For TBT, it appears that kinetics determine tissue residues and that body lipid is important only for regulating the toxic response, not the amount bioaccumulated. Unlike those for neutral hydrophobic organic compounds, the toxicokinetics for this one toxicant are highly variable in diverse species but relatively accurate in predicting the amount bioaccumulated and the resulting toxicity response. For the CBR approach to be useful, a relatively constant tissue residue for a given biological response is necessary. Several studies support the CBR approach because certain biological effects, such as mortality and growth inhibition, occur at a relatively constant TBT tissue concentration. For TBT, the lethal whole-body tissue concentration affecting 50% of individuals (LR50) exhibits little variation, occurring at approximately 48 micrograms/g (166 nmol/g) dry weight in a range of species. Direct evidence and correlation of the LC50 and the bioconcentration factor (BCF) support this observation. Impaired growth, a sublethal response, also appears to be associated with a relatively constant tissue concentration, which has also been demonstrated by direct measurement and indirectly by regression of the BCF and LOEC. The lowest-observed-effect tissue residue (LOER) associated with impaired growth for several species was approximately 3 micrograms/g (10.4 nmol/g) dry wt. Because of the small number of studies linking growth impairment and tissue concentrations, additional studies are needed to confirm these values. (ABSTRACT TRUNCATED)

Substituted benzamide inhibitors of human rhinovirus 3C protease: structure-based design, synthesis, and biological evaluation.

A series of nonpeptide benzamide-containing inhibitors of human rhinovirus (HRV) 3C protease was identified using structure-based design. The design, synthesis, and biological evaluation of these inhibitors are reported. A Michael acceptor was combined with a benzamide core mimicking the P1 recognition element of the natural 3CP substrate. alpha,beta-Unsaturated cinnamate esters irreversibly inhibited the 3CP and displayed antiviral activity (EC(50) 0.60 microM, HRV-16 infected H1-HeLa cells). On the basis of cocrystal structure information, a library of substituted benzamide derivatives was prepared using parallel synthesis on solid support. A 1.9 A cocrystal structure of a benzamide inhibitor in complex with the 3CP revealed a binding mode similar to that initially modeled wherein covalent attachment of the nucleophilic cysteine residue is observed. Unsaturated ketones displayed potent reversible inhibition but were inactive in the cellular antiviral assay and were found to react with nucleophilic thiols such as DTT.