Effects of ultraviolet radiation on metabolic rate and fitness of Aedes albopictus and Culex pipiens mosquitoes.

Natural and anthropogenic changes (e.g., land use change, pollution) will alter many environmental factors in the coming years, including the amount of solar radiation reaching the earth's surface. Alterations in solar radiation exposure is likely to impact the ecologies of many living organisms, including invertebrates that inhabit aquatic habitats. In this study, we assessed the effect of UV-B radiation on the metabolic rates and fitness (survival, development time, body size) of Aedes albopictus and Culex pipiens mosquitoes and the activity of their microbial food resources in experimental aquatic microcosms. We exposed single-species cohorts of newly hatched Ae. albopictus and Cx. pipiens larvae and a control treatment with no larvae to three UV-B conditions that mimicked those in full-sun and shade in the field and to a control condition with no UV-B radiation. Our results indicated that UV-B radiation affected the metabolic rates of both Ae. albopictus and Cx. pipiens larvae, with significantly higher rates found in full-sun compared to shade and no-UV conditions, 8 and 15 days after exposure began. Ae. albopictus and Cx. pipiens survival was also affected by UV-B radiation condition, with significantly lower survival in full-sun compared to shade and no UV-B conditions. Microbial metabolic rates were consistently significantly lower in full-sun compared to shade and no-UV conditions, especially at 8 days of exposure. These results show that UV-B radiation at levels found in open spaces showed strong and important impacts on the metabolic rates and survival of Ae. albopictus and Cx. pipiens larvae. Decreased survival of Ae. albopictus and Cx. pipiens with higher UV-B radiation levels may be caused by both direct exposure to radiation as well as the indirect effects of reduced microbial food, resulting in greater metabolic demands and stress. Negative impacts of UV-B radiation on the survival of Ae. albopictus and Cx. pipiens are likely to have important implications for the distribution and abundance of these mosquitoes, and the transmission of pathogens that these two broadly distributed mosquitoes vector.

Hydrology and Soil Manipulations of Iron-Rich Ditch Mesocosms Provide Little Evidence of Phosphorus Capture within the Profile.

Agricultural drainage ditches function as first-order streams and affect nutrient management. Soil mesocosms from a ditch featuring a vertical (increasing upward) gradient in iron (Fe) and phosphorus (P) were subjected to hydraulic and soil treatments. These manipulations mimicked aspects of dredging and controlled drainage and inspected the soil release and retention of P. Treatments did not remove P from simulated groundwater. Throughput water either gained in P (lack of dredging, especially under Fe-reducing conditions) or had P concentrations indistinguishable from input water (dredging). Undredged mesocosms, when Fe-reducing, released Fe and P simultaneously. Simultaneous release of P and Fe from our Fe-reducing mesocosms indicates a mechanism whereby P capture occurs by Fe precipitation upon emergence to aerated surficial waters. Upwelling and surficial phases of ditch hydrology and the lowering of the ditch surface on dredging complicate interpretation of traditional means of describing ditch P retention and release.

The Relationship between Diet Quality and Acculturation of Immigrated South Asian American Adults and Their Association with Metabolic Syndrome.

Even though the total SA American population is increasing rapidly, there is a paucity of information on the relationship between diet quality, acculturation and health outcomes such as Metabolic Syndrome (MetS) in the low-income South Asian (SA) sub-population. Our goal was to examine diet quality, degree of acculturation and their potential influence on MetS in a diverse sample of SA Americans. A convenience sample of 401 adult SA men and women were studied using a cross-sectional study design. Volunteers from two low-income community health clinics in Maryland were interviewed by questionnaires. MetS, defined by the consensus harmonized definition by the presence of ≥ 3 of the 5 abnormal indicators, was studied. An interviewer obtained an automated self-administered 24-hour Recall (ASA24) and an acculturation index (using a previously validated (SL-ASIA). SA had a composite HEI2010 score of 68 suggesting an overall need for diet improvements. Males had a higher diet quality (mean HEI2010 score) than females. Males with MetS had lower diet quality (68) than males without MetS (73). The converse was true for females (68 vs. 65). Americanized (more acculturated) subjects had a higher diet quality compared to less acculturated SA. Small differences were found in diet quality scores among SA adults from different countries. Less acculturated females, had a higher percentage of MetS and lower diet quality compared to males. These results suggest that interventions are needed in males and females who were less acculturated because they may have greater MetS and lower diet quality compared to more Americanized SA.

Photosynthetic and Growth Response of Sugar Maple (Acer saccharum Marsh.) Mature Trees and Seedlings to Calcium, Magnesium, and Nitrogen Additions in the Catskill Mountains, NY, USA.

Decline of sugar maple in North American forests has been attributed to changes in soil calcium (Ca) and nitrogen (N) by acidic precipitation. Although N is an essential and usually a limiting factor in forests, atmospheric N deposition may cause N-saturation leading to loss of soil Ca. Such changes can affect carbon gain and growth of sugar maple trees and seedlings. We applied a 22 factorial arrangement of N and dolomitic limestone containing Ca and Magnesium (Mg) to 12 forest plots in the Catskill Mountain region of NY, USA. To quantify the short-term effects, we measured photosynthetic-light responses of sugar maple mature trees and seedlings two or three times during two summers. We estimated maximum net photosynthesis (An-max) and its related light intensity (PAR at An-max), apparent quantum efficiency (Aqe), and light compensation point (LCP). To quantify the long-term effects, we measured basal area of living mature trees before and 4 and 8 years after treatment applications. Soil and foliar chemistry variables were also measured. Dolomitic limestone increased Ca, Mg, and pH in the soil Oe horizon. Mg was increased in the B horizon when comparing the plots receiving N with those receiving CaMg. In mature trees, foliar Ca and Mg concentrations were higher in the CaMg and N+CaMg plots than in the reference or N plots; foliar Ca concentration was higher in the N+CaMg plots compared with the CaMg plots, foliar Mg was higher in the CaMg plots than the N+CaMg plots; An-max was maximized due to N+CaMg treatment; Aqe decreased by N addition; and PAR at An-max increased by N or CaMg treatments alone, but the increase was maximized by their combination. No treatment effect was detected on basal areas of living mature trees four or eight years after treatment applications. In seedlings, An-max was increased by N+CaMg addition. The reference plots had an open herbaceous layer, but the plots receiving N had a dense monoculture of common woodfern in the forest floor, which can impede seedling survival.

A multiple logistic regression analysis of complications following microsurgical breast reconstruction.

BACKGROUND: Although we practice in an era of high flap success rates following microsurgical breast reconstruction, complications can still occur. Several studies have evaluated the impact of risk factors on microvascular outcomes in the setting of a particular type of patient or with a particular type of flap. However, few studies that have evaluated a consecutive series of high-risk patients will all types of microvascular breast reconstruction. Our goal was to gain a better understanding of the relationship between risk factors and complications in order to provide useful information for patients and surgeons considering free flap breast reconstruction in high-risk patients. METHODS: We performed a retrospective review of all patients who underwent microsurgical breast reconstruction by the senior author (M.Y.N) from July 2005 July 2010. Patient records were analyzed for risk factors (age, BMI, smoking history, medical history, adjunct therapies, timing of reconstruction, type of reconstruction), and complications (hematoma, seroma, infection, wound dehiscence, pulmonary embolism (PE), deep venous thrombosis (DVT), pneumonia, fat necrosis, leech use, partial flap loss, total flap loss). Statistical methods were employed to determine statistically significant relationships. RESULTS: A total of 352 patients underwent 490 microvascular breast reconstructions during the study period. Active smoking was found to be a statistically significant risk factor for seroma [P<0.0001; odds ratio (OR) =36; 95% confidence interval (CI), 5.9-193.9], infection (P=0.0081; OR =4.3; 95% CI, 1.3-14.1), and pneumonia (P<0.0001; OR =17.1; 95% CI, 3.3-89.9). Unilateral reconstruction was found to be a statistically significant factor for fat necrosis (P=0.0083; OR =4; 95% CI, 1.4-11.4). Additionally, BMI was found to be a statistically significant risk factor for infection (P<0.00001). CONCLUSIONS: This study corroborates findings from previous studies. Tobacco use was demonstrated to be a significant risk factor for infection, seroma, and pneumonia. Obesity was demonstrated to be a significant risk factor for infection. Unilateral reconstruction was demonstrated to pose additional risk for fat necrosis compared to bilateral reconstruction. Patients who choose to have microsurgical breast reconstruction should be informed of the complication profile associated with certain risk factors.

Electrocortical dynamics reflect age-related differences in movement kinematics among children and adults.

Previous neuroimaging and behavioral studies demonstrated structural and functional changes in the motor system across childhood. However, it is unclear what functionally relevant electrocortical processes underlie developmental differences in motor planning and control during multijoint, goal-directed movements. The current study characterized age-related differences in electrocortical processes during the performance of discrete aiming movements in children and adults. Electroencephalography and movement kinematics were recorded from 3 groups of participants (n = 15 each): young children (mean 6.7 years), older children (mean 10.2 years), and adults (mean 22.1 years). Age-related differences were evident in the electroencephalographic (EEG) signals. First, young children exhibited less movement-related activity in task-relevant motor areas compared with adults (movement-related cortical potentials). Second, young children exhibited greater activation (less alpha power) of the frontal areas and less activation of the parietal areas as compared with the other groups. At the behavioral level, young children made slower and jerkier movements, with less consistent directional planning compared with older children and adults. Significant correlations were also found between EEG and movement kinematic measures. Taken together, the results of this study provide evidence that age-related differences in the quality of motor planning and performance are reflected in the differences in electrocortical dynamics among children and adults.

Morphology and gonad development of normal soldiers and reproductive soldiers of the termite Zootermopsis nevadensis nevadensis (Isoptera, Archotermopsidae).

Reproductive or neotenic soldiers of the Archotermopsid Zootermopsis nevadensisnevadensis (Hagen) are compared to sterile soldiers and primary male reproductives. Several head capsule morphometrics correlate significantly with gonad size across all forms and both sexes of soldiers. The easily observed field character of ratio of mandible length to labrum length is a consistent and reliable feature of head capsule external morphology for predicting gonad development and reproductive potential of soldier forms regardless of age, sex, or live weight.

Acidification in the Adirondacks: defining the biota in trophic levels of 30 chemically diverse acid-impacted lakes.

The Adirondack Mountains in New York State have a varied surficial geology and chemically diverse surface waters that are among the most impacted by acid deposition in the U.S. No single Adirondack investigation has been comprehensive in defining the effects of acidification on species diversity, from bacteria through fish, essential for understanding the full impact of acidification on biota. Baseline midsummer chemistry and community composition are presented for a group of chemically diverse Adirondack lakes. Species richness of all trophic levels except bacteria is significantly correlated with lake acid-base chemistry. The loss of taxa observed per unit pH was similar: bacterial genera (2.50), bacterial classes (1.43), phytoplankton (3.97), rotifers (3.56), crustaceans (1.75), macrophytes (3.96), and fish (3.72). Specific pH criteria were applied to the communities to define and identify acid-tolerant (pH<5.0), acid-resistant (pH 5.0-5.6), and acid-sensitive (pH>5.6) species which could serve as indicators. Acid-tolerant and acid-sensitive categories are at end-points along the pH scale, significantly different at P<0.05; the acid-resistant category is the range of pH between these end-points, where community changes continually occur as the ecosystem moves in one direction or another. The biota acid tolerance classification (batc) system described herein provides a clear distinction between the taxonomic groups identified in these subcategories and can be used to evaluate the impact of acid deposition on different trophic levels of biological communities.

Deletion of Drosophila insulin-like peptides causes growth defects and metabolic abnormalities.

Insulin/Insulin-like growth factor signaling regulates homeostasis and growth in mammals, and is implicated in diseases from diabetes to cancer. In Drosophila melanogaster, as in other invertebrates, multiple Insulin-Like Peptides (DILPs) are encoded by a family of related genes. To assess DILPs' physiological roles, we generated small deficiencies that uncover single or multiple dilps, generating genetic loss-of-function mutations. Deletion of dilps1-5 generated homozygotes that are small, severely growth-delayed, and poorly viable and fertile. These animals display reduced metabolic activity, decreased triglyceride levels and prematurely activate autophagy, indicative of "starvation in the midst of plenty," a hallmark of Type I diabetes. Furthermore, circulating sugar levels are elevated in Df [dilp1-5] homozygotes during eating and fasting. In contrast, Df[dilp6] or Df[dilp7] animals showed no major metabolic defects. We discuss physiological differences between mammals and insects that may explain the unexpected survival of lean, 'diabetic' flies.

Increased pathogenicity against coffee berry borer, Hypothenemus hampei (Coleoptera: Curculionidae) by Metarhizium anisopliae expressing the scorpion toxin (AaIT) gene.

Coffee berry borer (CBB) is the Worlds most devastating coffee pest causing an estimated US$500 million worth of losses annually through damage and control costs. Beauveria bassiana and Metarhizium anisopliae have been employed to control this pest but their low virulence (slow kill and large inoculums) is an important factor constraining their use. M. anisopliae (AaIT-Ma549) has been modified to express the scorpion toxin (AaIT) in insect hemolymph and this greatly increased pathogenicity against Manduca sexta and Aedes aegypti. Here, we demonstrate that AaIT-Ma549 was also dramatically more virulent against CBB, and we provide a much more comprehensive analysis of infection processes and post-mortality development than in the previous research. We evaluated several spore concentrations (10(1) through 10(7)spores/ml) of both the wild type and recombinant strain. At concentrations of 10(1), 10(2) and 10(3)spores/ml, the recombinant strain significantly increased mortality of CBB by 32.2%, 56.6% and 24.6%, respectively. The medial lethal concentration (LC(50)) was reduced 15.7-fold and the average survival time (AST) was reduced by 20.1% to 2.98+/-0.1 days with 10(7)spores/ml. This is the first occasion that an entomopathogenic fungus has been found to kill CBB in less than 3 days. However, AaIT-Ma549 produces significantly fewer spores on cadavers than the parental strain.

The impact of breast reconstruction on the oncologic efficacy of radiation therapy: a retrospective analysis.

Current indications for radiation therapy in women with breast cancer are controversial and continue to be modified. Current indications for breast reconstruction in the setting of radiation therapy are also controversial and poorly defined. The purpose of this study is to analyze oncologic outcomes following various methods of breast reconstruction in the setting of radiation therapy. A retrospective review of 676 women who had breast reconstruction following mastectomy was completed. A total of 146 women had breast reconstruction either before or after radiation therapy and were analyzed. Response variables included tumor recurrence and patient demise for patients having autologous and prosthetic reconstruction. Explanatory variables included patient age, cancer stage, radiation therapy, diabetes mellitus, and tobacco use. Recurrence of tumor occurred in 29 of 146 women (19.8%), of which 27% was when radiation followed reconstruction and 14.9% was when radiation preceded reconstruction. Patient demise occurred in 8.9%, of which 11.9% was when radiation followed reconstruction and 6.9% was when radiation preceded reconstruction. The difference in tumor recurrence in the setting of radiation therapy before or after breast reconstruction was significant for autologous (P = 0.0146) and prosthetic (P = 0.0424) reconstruction. The difference in patient demise was significant for autologous reconstruction (P = 0.0380) but not for prosthetic reconstruction (P = 0.2827). These results imply that tumor recurrence and patient demise may be increased when radiation therapy is performed following breast reconstruction. The need for a prospective inquiry is validated.

Lead forms in urban turfgrass and forest soils as related to organic matter content and pH.

Soil pH may influence speciation and extractability of Pb, depending on type of vegetation in urban soil environments. We investigated the relationship between soil pH and Pb extractability at forest and turf grass sites in Baltimore, Maryland. Our two hypotheses were: (1) due to lower pH values in forest soils, more Pb will be in exchangeable forms in forested than in turfgrass soils and (2) due to the greater lability of exchangeable Pb in equilibrium with soil solution in forest soils, concentrations of this form will increase with depth more so than in the turfgrass soils, as related to organic matter content and pH. Soil samples were collected from three forested and three turfgrass sites to depths of 20 cm. Lead forms were determined using a sequential extraction technique. Soils under turfgrass and forest vegetation differed in the extractability of soil Pb (P < 0.01) for the Mn(III, IV)- and Fe(III)(hydr) oxide fraction. A greater Pb concentration was bound to this fraction under turfgrass (211 mg kg(-1), 69% of total Pb) than forested soils (67 mg kg(-1), 61% of total Pb), perhaps due to soil pH differences of 5.9 and 5.0, respectively. In the forested soils, as depth increased, the ratio of exchangeable-to-total Pb increased and the ratio of organically bound Pb-to-total Pb decreased. The results suggest changes in pH and organic matter content with depth affect the extractability of Pb, and these soil properties are affected differentially by grass versus tree vegetation in the urban soils investigated.

The psychrophilic lifestyle as revealed by the genome sequence of Colwellia psychrerythraea 34H through genomic and proteomic analyses.

The completion of the 5,373,180-bp genome sequence of the marine psychrophilic bacterium Colwellia psychrerythraea 34H, a model for the study of life in permanently cold environments, reveals capabilities important to carbon and nutrient cycling, bioremediation, production of secondary metabolites, and cold-adapted enzymes. From a genomic perspective, cold adaptation is suggested in several broad categories involving changes to the cell membrane fluidity, uptake and synthesis of compounds conferring cryotolerance, and strategies to overcome temperature-dependent barriers to carbon uptake. Modeling of three-dimensional protein homology from bacteria representing a range of optimal growth temperatures suggests changes to proteome composition that may enhance enzyme effectiveness at low temperatures. Comparative genome analyses suggest that the psychrophilic lifestyle is most likely conferred not by a unique set of genes but by a collection of synergistic changes in overall genome content and amino acid composition.

Clinicopathological features and microsatellite instability (MSI) in colorectal cancers from African Americans.

African Americans (AAs) have a 1.5 times higher risk of colorectal carcinoma (CRC) than Caucasians. Gene silencing through CpG island hypermethylation has been associated with the genesis or progression of microsatellite instability (MSI) largely due to 1 target for hypermethylation being the DNA mismatch repair gene hMLH1; there is anecdotal evidence of an increased incidence of MSI among AAs. P16 and hMLH1 can be inactivated by hypermethylation of their respective promoter regions, abrogating the ability to regulate cell proliferation and repair processes. We studied such methylation, as well as hMHS2 expression in colorectal cancers from AA patients to determine if MSI is associated with epigenetic silencing. Experiments were conducted on matched normal and colon cancer tissues from AA patients (n = 51). A total of 5 microsatellite markers (D2S123, D5S346, D17S250, BAT25 and BAT26) were used to evaluate MSI status. P16 and hMLH1 promoter methylation status was determined following bisulfite modification of DNA and using methylation specific PCR, while immunohistochemistry (IHC) was used to examine expression of hMLH1 and hMSH2. A total of 22 (43%) cancers demonstrated microsatellite instability-high (MSI-H), while 27 were microsatellite stable (MSS) and 2 were microsatellite instability-low (MSH-L). Most of the MSI-H tumors were proximal, well differentiated and highly mucinous. Most patients in the MSI-H group were females (68%). The p16 promoter was methylated in 19 of 47 (40%) tumors. A total of 7 of these CRCs demonstrated MSI-H (33%). The hMLH1 promoter was methylated in 29 of 34 (85%) tumors, of which 13 CRCs demonstrated MSI-H (87%). hMLH1 and hMSH2 staining was observed in 66% and 38% of MSI-H tumors, respectively. Overall, the prevalence of MSI-H colorectal tumor was 2-3-fold higher, while the defect in the percentage expression of mismatch repair (MMR) genes (hMLH1 and hMSH2) was similar in AA patients compared to the U.S. Caucasian population. Similar numbers of AA MSS tumors with p16 and hMLH1 methylation likely indicate hemimethylation of genes that might reflect environmental or genetic influences that might be more common in the AA population.

Breast reconstruction with the DIEP flap or the muscle-sparing (MS-2) free TRAM flap: is there a difference?

The advantages of breast reconstruction using the deep inferior epigastric perforator (DIEP) flap and the muscle-sparing free transverse rectus abdominis musculocutaneous (TRAM) flap (MS-2) are well recognized. Both techniques optimize abdominal function by maintaining the vascularity, innervation, and continuity of the rectus abdominis muscle. The purpose of this study was to compare these two methods of breast reconstruction and determine whether there is a difference in outcome. The study considered 177 women who have had breast reconstruction using muscle-sparing flaps over a 4-year period. This includes 89 women who had an MS-2 free TRAM flap procedure, of which 65 were unilateral and 24 were bilateral, and 88 women who had a DIEP flap procedure, of which 66 were unilateral and 22 were bilateral. The total number of flaps was 223. Mean follow-up was 23 months (range, 3 to 49 months). For all MS-2 free TRAM flaps (n = 113), outcome included fat necrosis in eight (7.1 percent), venous congestion in three (2.7 percent), and total necrosis in two (1.8 percent). For the women who had an MS-2 free TRAM flap, an abdominal bulge occurred in three women (4.6 percent) after unilateral reconstruction and in five women (21 percent) after bilateral reconstruction. The ability to perform sit-ups was noted in 63 women (97 percent) after unilateral reconstruction and 20 women (83 percent) after bilateral reconstruction. For all DIEP flaps (n = 110), outcome included fat necrosis in seven (6.4 percent), venous congestion in five (4.5 percent), and total necrosis in three (2.7 percent) patients. For the women who had DIEP flap reconstruction, an abdominal bulge occurred in one woman (1.5 percent) after unilateral reconstruction and in one woman (4.5 percent) after bilateral reconstruction. The ability to perform sit-ups was noted in all women after unilateral reconstruction and in 21 women (95 percent) after bilateral reconstruction. These results demonstrate that there are no significant differences in fat necrosis, venous congestion, or flap necrosis after DIEP or MS-2 free TRAM flap reconstruction. The percentage of women who are able to perform sit-ups and the percentage of women who did not develop a postoperative abdominal bulge is increased after DIEP flap reconstruction; however, this difference is not statistically significant.

Lower abdominal bulge after deep inferior epigastric perforator flap (DIEP) breast reconstruction.

The etiology of lower abdominal bulge following breast reconstruction with the DIEP flap is uncertain. Most studies report an incidence that ranges from 0.7% to 5%. The purpose of this study was to review a set of factors that may predispose to a lower abdominal bulge. This was a retrospective review of 123 women who had breast reconstruction with the DIEP flap over a 4-year period. The reconstruction was unilateral in 93 women and bilateral in 30 women, totaling 153 flaps. Etiologic factors that were evaluated included patient age, diabetes mellitus, tobacco use, previous abdominal operations, unilateral or bilateral reconstruction, previous childbirth, aponeurotic plication to improve the natural abdominal contour, and use of Marlex mesh. A lower abdominal bulge occurred in 5 of the 123 women (4%), 2 following 30 bilateral reconstructions (6.6%) and 3 following 93 unilateral reconstructions (3.2%). Analysis of the factors for all women demonstrated diabetes mellitus in 1 (0.8%), tobacco use in 9 (7.3%), a prior abdominal operation in 55 (44.7%), previous childbirth in 95 (77%), aponeurotic plication in 49 (40%), and use of Marlex mesh in 4 (3.3%). Statistical analysis did not show any significant association between the explanatory factors and the occurrence of a lower abdominal bulge, except for a weak trend in women who had not been pregnant (P = 0.08). The results of this study demonstrate that the occurrence of a lower abdominal bulge following the DIEP flap is a random event that can occur in anyone. Pregnancy may confer a preventative effect as the collagen fibers strengthen to overcome the stretching forces. Techniques for prevention and treatment include intraoperative assessment of the anterior rectus sheath, use of an adjuvant material for reinforcement if unstable, and vertical plication for bulge repair.

Use of stream chemistry for monitoring acidic deposition effects in the Adirondack region of New York.

Acid-neutralizing capacity (ANC) and pH were measured weekly from October 1991 through September 2001 in three streams in the western Adirondack Mountain region of New York to identify trends in stream chemistry that might be related to changes in acidic deposition. A decreasing trend in atmospheric deposition of SO4/2- was observed within the region over the 10-yr period, although most of the decrease occurred between 1991 and 1995. Both ANC and pH were inversely related to flow in all streams; therefore, a trend analysis was conducted on (i) the measured values of ANC and pH and (ii) the residuals of the concentration-discharge relations. In Buck Creek, ANC increased significantly (p < 0.05) over the 10 yr, but the residuals of ANC showed no trend (p > 0.10). In Bald Mountain Brook, ANC and residuals of ANC increased significantly (p < 0.01), although the trend was diatonic-a distinct decrease from 1991 to 1996 was followed by a distinct increase from 1996 to 2001. In Fly Pond outlet, ANC and residuals of ANC increased over the study period (p < 0.01), although the trend of the residuals resulted largely from an abrupt increase in 1997. In general, the trends observed in the three streams are similar to results presented for Adirondack lakes in a previous study, and are consistent with the declining trend in atmospheric deposition for this region, although the observed trends in ANC and pH in streams could not be directly attributed to the trends in acidic deposition.

Factors associated with anastomotic failure after microvascular reconstruction of the breast.

The prevalence of anastomotic failure resulting in return to the operating room and flap necrosis after microvascular breast reconstruction ranges from 1 to 5 percent. The purpose of this study was to review a set of factors that may be associated with this occurrence. Microvascular reconstruction of the breast was performed in 198 women from January of 1998 to July of 2002. The mean age for all women was 47.7 years. There were 158 unilateral and 41 bilateral reconstructions, for a total of 240 flaps. The specific flaps included the free transverse rectus abdominis musculocutaneous flap (n = 176), the deep inferior epigastric perforator flap (n = 58), and the superior gluteal artery perforator flap (n = 6). Upon recognition of anastomotic failure, women were immediately returned to the operating room. Factors that were considered relevant to anastomotic failure included the choice of recipient vessel, timing of reconstruction, previous chest wall radiation therapy, previous axillary lymph node dissection, tobacco use, diabetes mellitus, patient age, and hematoma. Patient follow-up ranged from 5 to 59 months. Descriptive statistics, Fisher's exact test, and exact logistic regression were used for analyses and to summarize data. Of the 240 flaps, return to the operating room was necessary for 20 (8.3 percent), total necrosis occurred in nine (3.8 percent), and the rate of flap salvage was 55 percent (11 of 20 flaps). Venous occlusion was responsible for 16 of the 20 returns and eight of the nine failures. Statistical analysis demonstrated that both return to the operating room and flap necrosis were significantly associated with venous occlusion, delayed reconstruction, and hematoma. Previous lymph node dissection and previous radiation therapy had only a weak association with return to the operating room. The results of this study demonstrate that venous occlusion is responsible for return to the operating room and flap necrosis in the majority of cases. Age, tobacco use, choice of recipient vessel, and diabetes mellitus were not associated with anastomotic failure. The significance of delayed reconstruction may be related to its frequent association with previous lymph node dissection and/or radiation therapy resulting in perivascular fibrosis.

Infectious complications following breast reconstruction with expanders and implants.

The incidence of infection following breast reconstruction with expanders and implants ranges from 1 to 24 percent. Numerous factors associated with infection have been described; however, a one-variable at time setting and multifactorial analysis have not been performed. The purpose of this study was to analyze a set of factors that may predispose women to infection of the expander or implant. Between 1997 and 2000, a total of 168 implant reconstructions were performed in 130 women at a single institution. The mean age for all women was 48.2 years (range, 25 to 77 years). The factors that were analyzed included axillary lymph node dissection, chemotherapy, radiation therapy, tumor stage, timing of implant insertion, number of sides (unilateral versus bilateral), tobacco use, and presence or absence of diabetes mellitus. Statistical analysis was performed with stepwise logistic regression. Mean time to follow-up for all patients was 29 months (range, 12 to 47 months). Infectious complications occurred in 10 women (7.7 percent) and in 10 expanders or implants (5.9 percent). Infected implants were removed an average of 116 days following insertion (range, 14 to 333 days). Cultured bacteria included Staphylococcus aureus and Serratia marcescens. A significant association (p < 0.04) was detected between implant infection and radiation therapy. The chance for implant infection was 4.88 times greater for implants that were exposed to radiation therapy compared with those that were not. In addition, there was suggestive (p < 0.09) evidence that the chance of implant infection following lymph node dissection was 6.29 times higher than when no lymph nodes were removed. No significant association between implant infection and age, diabetes, tobacco use, tumor stage, timing of implant insertion, or chemotherapy was found.

High incidence of microsatellite instability in colorectal cancer from African Americans.

PURPOSE: Colorectal carcinoma (CRC) is the second most common cause of cancer death in the United States, and the rate of CRC is nearly 1.5 times higher in African-Americans (AA) than in Caucasians. Microsatellite instability (MSI) is observed in sporadic CRC reflecting promoter hypermethylation of the DNA mismatch repair gene hMLH1, and anecdotal evidence suggests an increased incidence of MSI among AAs. Additionally, p16 can be inactivated by hypermethylation of the promoter region, abrogating its ability to regulate cell proliferation. The objective of this study is to determine the frequency of MSI and p16 gene methylation in CRC from AA patients. EXPERIMENTAL DESIGN: Experiments were conducted on serially collected archival samples of colon cancer and adjacent normal tissue (n = 22). Five microsatellite markers were used to measure MSI in tumors with direct comparison to normal tissue from the same patient. p16 promoter methylation status was determined by methylation-specific PCR. RESULTS: Ten cancers (45%) demonstrated high MSI (MSI-H), 1 demonstrated low MSI, and the remaining 11 tumors were microsatellite stable. Most of the MSI-H tumors were proximal, well differentiated, and showed high levels of mucin production. Most patients in the MSI-H group were female (70%), whereas most of the microsatellite-stable group (81%) were male. Five of the 22 tumors (22%) had methylation of the p16 promoter. CONCLUSION: Data provided here demonstrated that the incidence of MSI-H tumors was 3-fold higher in our study group of AA patients compared with data reported in nonracially selected but serially collected studies. Odds ratio analysis indicates that the chance of female patients having MSI-H was 11.7 times more than male patients (P < 0.03). The reason for this gender difference is unknown. These findings might reflect dietary differences or genetic polymorphisms that may be common in the AA population. Additional investigation in a larger patient population is needed before strong conclusion can be drawn.