Utilization of the Free Fibular Flap for First Metatarsal Reconstruction.

Beyond being aesthetically unpleasing, metatarsal defects have been known to lead to several patient concerns such as intermetatarsal malpositioning and metatarsalgia. There are several reconstructive techniques that have been utilized for reconstruction of bony defects in the foot, including the free dorsal toe flap and dorsal metatarsal perforator flap. Our institution has utilized the free fibular flap for surgical management pertaining to tarsal reconstruction. Our study looks to evaluate the work of a single plastic surgeon and identify patient postoperative outcomes. A retrospective chart review was conducted at Beaumont Health System, Royal Oak for patients who underwent first metatarsal reconstruction with a free fibular flap between the years 2015 and 2022. Demographic data, operative details, complications, medical comorbidities, and patient outcomes were retrospectively gathered and analyzed. A total of two patients were isolated after chart review. Both patients were found to have tolerated the procedure well and had no intraoperative complications. In addition, all patients had clinically viable flaps and were satisfied with their surgical results. The free fibular flap may be used effectively in the management of metatarsal defects that have failed prior therapy. In our study, both patients who underwent surgical management with a free fibular flap were noted to have successful long-term results. With the right expertise and patient population, a free fibular flap can be highly successful in the repair of metatarsal defects.

Utilization of the Pedicled and Free Fibula Flap for Ankle Arthrodesis.

Ankle arthrodesis has become a common surgical procedure for individuals with end-stage ankle arthritis, chronic infection, and bony misalignment. Although arthrodesis is typically managed with arthrodesis in situ or realignment, reconstruction may be utilized for patients with more complicated cases that involve metatarsal defects. Our institution utilizes both the pedicled and free fibula flaps for surgical management pertaining to ankle arthrodesis. Our study looks to evaluate the work of a single plastic surgeon and identify patient postoperative outcomes. Methods: A retrospective chart review was conducted at Beaumont Health System, Royal Oak, for patients who underwent ankle arthrodesis with a pedicled fibula flap for nonunion or avascular necrosis of the talus between the years 2014 and 2022. Demographic data, operative details, complications, medical comorbidities, and patient outcomes were retrospectively gathered and analyzed. Results: A total of six patients were isolated, with three patients undergoing a free fibula approach and three patients undergoing the pedicled fibula approach. All patients were found to have tolerated the procedure well and had no intraoperative complications. In addition, all patients had clinically viable flaps and were satisfied with their surgical result. Conclusions: Both free and pedicled free fibula flaps may be used effectively in the management of ankle arthrodesis in patients who have failed prior therapy. In our study, free fibula flaps were utilized in a medial approach, while the pedicled fibula flap was utilized in a lateral approach. With the right expertise and patient population, the free and pedicled fibula flaps can be highly successful in the repair of ankle defects.

A Practical Screening Tool to Predict Early Childhood Obesity Risk: Examining a Birth Cohort.

Children obese at the age of 5 years are at greater risk of lifelong obesity. Because certain risks of obesity can be identified in early infancy, a tool for obesity risk prediction in early life would be clinically useful. We investigated predictors of obesity risk in a novel, prospectively collected healthy birth cohort recruited for demographic risks to develop iron deficiency at 1 year, a cohort leveraged because risk factors for iron deficiency and obesity overlap. Obesity at the age of 5 years was defined as age- and sex-specific body mass index Z-score (zBMI) >2SD. For each child, obesity risk factors were summed. Of 10 total risk factors, the following 4 key risks were identified: maternal obesity, maternal diabetes, large for gestational age, or breastfeeding <6 months. Childhood obesity was predicted by either ≥3 total number of risks (P < .033), any key risk (P < .002), or summing key risks (P < .0001). In clinical practice, summing early life risk factors may be a useful strategy for preemptive counseling.

Posterior Surgical Approach to the Knee.

Posterior knee approaches are reliable techniques to address the treatment of various pathologies of the posterior region of the knee, including Baker cyst excision, tibial plateau fracture fixation, posterior cruciate ligament avulsions and inlay reconstructions, femoral condyle cartilage procedures, posterior meniscal repair and loose body removal among others. Surgery in the posterior knee region can be challenging because of the presence of neurovascular structures including the tibial nerve, popliteal artery and vein, and common peroneal nerve; thus, it is less commonly performed. The purpose of this Technical Note is to describe the posteromedial approach to the knee, its anatomic considerations, and how to avoid complications related to the surgical approach.

Role of Repeat 18F-Fluorodeoxyglucose Positron Emission Tomography Examination in Predicting Pathologic Response Following Neoadjuvant Chemoradiotherapy for Esophageal Adenocarcinoma.

IMPORTANCE: Predicting complete pathologic response (CPR) preoperatively can significantly affect surgical decision making. There are conflicting data regarding positron emission tomography computed tomography (PET CT) characteristics and the ability of PET CT to predict pathologic response following neoadjuvant chemoradiotherapy in esophageal adenocarcinoma because most existing studies that include squamous histology have limited numbers and use nonstandardized PET CT imaging. OBJECTIVE: To determine if PET CT characteristics are associated with CPR in patients undergoing trimodality treatment for esophageal adenocarcinoma. DESIGN, SETTING, AND PARTICIPANTS: A retrospective medical record review was conducted at a large tertiary cancer center from a prospectively maintained database from January 1, 2005, to December 31, 2012. Inclusion criteria were patients undergoing esophagectomy for locally advanced esophageal adenocarcinoma post-neoadjuvant chemoradiotherapy with 2 standardized PET CT studies done at our institution (pre-neoadjuvant chemoradiotherapy and post-neoadjuvant chemoradiotherapy) for review. Data collected included clinical, pathologic, imaging, and treatment characteristics. MAIN OUTCOME AND MEASURE: The primary study outcome was the association of PET CT characteristics with histologic confirmed pathologic response. RESULTS: Of the total participants, 77 patients met the inclusion criteria. Twenty-two patients (28.6%) had CPR vs 55 patients (71.4%) who had incomplete pathologic response. The 2 groups were similar in age, sex, race/ethnicity, comorbid conditions, Eastern Cooperative Oncology Group status, tumor grade, chemotherapy, and radiation regimen and days between the 2 PET CTs. The mean prestandardized uptake variable (SUV; 14.5 vs 11.2; P = .05), δ SUV (10.3 vs 5.4; P = .02), and relative δ SUV (0.6 vs 0.4; P = .02) were significantly higher in those with CPR vs incomplete pathologic response. Using the Youden Index, a δ SUV value less than 45% was predictive of residual disease with a positive predictive value of 91.7% (95% CI, 73-99; P < .05). CONCLUSIONS AND RELEVANCE: To our knowledge, this is the largest study examining the role of PET CT characteristics in esophageal adenocarcinoma for patients undergoing neoadjuvant chemoradiotherapy that demonstrates that δ SUV of less than 45% is associated with patients with residual disease but not CPR. Based on the findings from our study, the current recommendation is still surgical resection regardless of the posttherapy PET SUV in the primary tumor. However, our study highlights the ability to detect patients with residual disease and the need to critically evaluate these patients for consideration of additional therapies.

Phase II study of perioperative chemotherapy with cisplatin and pemetrexed in non-small-cell lung cancer.

INTRODUCTION: Pathologic complete response (pCR) with neoadjuvant chemotherapy is associated with improved survival in many solid tumors. We evaluated pCR rate of cisplatin with pemetrexed in non-small-cell lung cancer. METHODS: Patients with stages IB to IIIA non-small-cell lung cancer, Eastern Cooperative Oncology Group performance status 0 to 1 were enrolled in this single-arm phase II trial using two-stage design with 90% power to detect pCR rate of more than or equal to 10%. Pretreatment mediastinal lymph node biopsy was required. Patients received three cycles of cisplatin 75 mg/m with pemetrexed 500 mg/m (day 1 every 21 days) preoperatively and additional two cycles within 60 to 80 days after surgery. The primary end point was pCR. Polymorphisms in FPGS, GGH, SLC19A1, and TYMS genes were correlated with treatment outcomes. RESULTS: Thirty-eight patients were enrolled, with median age of 62.5 years. Preoperatively, 26% had squamous histology, and 34% had biopsy-proven N2 involvement. R0 resection was achieved in 94% of the 34 patients who underwent surgery, and 54% had documented N2 clearance. There was no pCR seen. Median disease-free survival (DFS) and overall survival of these patients have not yet been reached in contrast to median of 13.8 and 24.2 months, respectively, in patients with persistent N2 disease (p = 0.3241 and p = 0.1022, respectively). There was a statistically significant association between DFS and postoperative tumor, node, metastasis stage (p = 0.0429), SLC19A1 rs3788189 TT genotype (p = 0.0821), and viable tumor defined as less than or equal to 10% of resected specimen (p = 0.026). CONCLUSION: The primary end point was not met. Patients with N2 clearance, less than or equal to 10% viable tumor in the resected specimen, and SLC19A1 rs3788189 TT genotype have favorable DFS outcomes.

Heavy metal tolerance genes alter cellular thermodynamics in Pseudomonas putida and river Pseudomonas spp. and influence amebal predation.

Predation rates were measured for two Acanthamoeba castellanii strains feeding on metal-tolerant and metal-sensitive strains of Pseudomonas putida and compared with cellular thermodynamic data. Predation rates by A. castellanii strain ATCC 30010 correlated with cell volume of the prey. To explore whether this observation could be environmentally relevant, pseudomonad species were isolated from a pristine and a metal-contaminated river and were paired based on phylogenetic and physiological relatedness. Then, cellular thermodynamics and predation rates were measured on the most similar pseudomonad pair. Under cadmium stress, the strain from contaminated river sediments, Pseudomonas sp. CF150, exited metabolic dormancy faster than its pair from pristine sediments, Pseudomonas sp. N9, but consumed available resources less efficiently (more energy was lost as heat). Predation rates by both strains of ameba were greater on Pseudomonas sp. CF150 than on Pseudomonas sp. N9 at the highest cadmium concentration.

Use of microcalorimetry to determine the costs and benefits to Pseudomonas putida strain KT2440 of harboring cadmium efflux genes.

A novel microcalorimetric approach was used to analyze the responses of a metal-tolerant soil bacterium (Pseudomonas putida strain KT2440) to metal resistance gene deletions in cadmium-amended media. As hypothesized, under cadmium stress, the wild-type strain benefited from the resistance genes by entering the exponential growth phase earlier than two knockout strains. In the absence of cadmium, strain KT1, carrying a deletion in the main component (czcA1) of a Cd/Zn chemiosmotic efflux transporter (CzcCBA1), grew more efficiently than the wild type and released ∼700 kJ (per mole of biomass carbon) less heat than the wild-type strain, showing the energetic cost of maintaining CzcCBA1 in the absence of cadmium. A second mutant strain (KT4) carrying a different gene deletion, ΔcadA2, which encodes the main Cd/Pb efflux transporter (a P-type ATPase), did not survive beyond moderate cadmium concentrations and exhibited a decreased growth yield in the absence of cadmium. Therefore, CadA2 plays an essential role in cadmium resistance and perhaps serves an additional function. The results of this study provide direct evidence that heavy metal cation efflux mechanisms facilitate shorter lag phases in the presence of metals and that the maintenance and expression of tolerance genes carry quantifiable energetic costs and benefits.

Hyporheic microbial community development is a sensitive indicator of metal contamination.

Accurate natural resource damage assessment necessitates monitoring organisms or communities that respond most sensitively to contaminants. Observational studies have demonstrated a correlation between fluvial heavy metal deposition and hyporheic microbial community structure. To establish a causal relationship between sediment metal content and the structure of colonizing bacterial communities, we performed a controlled field experiment River sediments of 1.75-2.36 mm in diameter with five different contaminant concentrations were collected from an environmental metal contamination gradient. Sediments were sterilized and then recolonized by incubation in the hyporheic zone of an uncontaminated river (i.e., a common garden experiment was performed). A significant correlation between hyporheic microbial community structure and heavy metal contamination (R2 = 0.81) was observed. The abundance of two phylogenetic groups was highly correlated with the level of heavy metal contamination (Group I, R2 = 0.96; Group III, R2 = 0.96, most closely affiliated with the alpha- and gamma-proteobacteria, respectively). Microbial community structural responses were detected at metal concentrations an order of magnitude lower than those previously reported to impact benthic macroinvertebrate communities. We conclude that hyporheic microbial communities could offer the most sensitive method for assessing natural resource damage in lotic ecosystems in response to fluvial heavy metal deposition.

Pedobacter nyackensis sp. nov., Pedobacter alluvionis sp. nov. and Pedobacter borealis sp. nov., isolated from Montana flood-plain sediment and forest soil.

Three Gram-negative, rod-shaped, non-spore-forming eubacterial strains were isolated in western Montana, USA, and subjected to taxonomic studies. Strains NWG-II14(T) and NWER-II11(T) were isolated from hyporheic sediments of a large alluvial flood plain, whereas strain G-1(T) was isolated from a conifer forest soil. On the basis of 16S rRNA gene sequence similarity, strains NWG-II14(T), NWER-II11(T) and G-1(T) were shown to belong to the family Sphingobacteriaceae and are most closely related to various species of the genus Pedobacter. The results of molecular, physiological and biochemical tests allowed genotypic and phenotypic differentiation of these three strains from 23 Pedobacter species with validly published names. The three isolates therefore represent novel species, for which the names Pedobacter nyackensis sp. nov. (type strain NWG-II14(T) =DSM 19625(T) =LMG 24260(T)), Pedobacter alluvionis sp. nov. (type strain NWER-II11(T) =DSM 19624(T) =LMG 24258(T)) and Pedobacter borealis sp. nov. (type strain G-1(T) =DSM 19626(T) =LMG 24259(T)) are proposed.

Habitat heterogeneity and associated microbial community structure in a small-scale floodplain hyporheic flow path.

The Nyack floodplain is located on the Middle Fork of the Flathead River, an unregulated, pristine, fifth-order stream in Montana, USA, bordering Glacier National Park. The hyporheic zone is a nutritionally heterogeneous floodplain component harboring a diverse array of microbial assemblages essential in fluvial biogeochemical cycling, riverine ecosystem productivity, and trophic interactions. Despite these functions, microbial community structure in pristine hyporheic systems is not well characterized. The current study was designed to assess whether physical habitat heterogeneity within the hyporheic zone of the Nyack floodplain was sufficient to drive bacterial beta diversity between three different hyporheic flow path locations. Habitat heterogeneity was assessed by measuring soluble reactive phosphorous, nitrate, dissolved organic carbon, dissolved oxygen, and soluble total nitrogen levels seasonally at surface water infiltration, advection, and exfiltration zones. Significant spatial differences were detected in dissolved oxygen and nitrate levels, and seasonal differences were detected in dissolved oxygen, nitrate, and dissolved organic carbon levels. Denaturing gradient gel electrophoresis (DGGE) and cell counts indicated that bacterial diversity increased with abundance, and DGGE fingerprints covaried with nitrate levels where water infiltrated the hyporheic zone. The ribosomal gene phylogeny revealed that hyporheic habitat heterogeneity was sufficient to drive beta diversity between bacterial assemblages. Phylogenetic (P) tests detected sequence disparity between the flow path locations. Small distinct lineages of Firmicutes, Actinomycetes, Planctomycetes, and Acidobacteria defined the infiltration zone and alpha- and beta-proteobacterial lineages delineated the exfiltration and advection zone communities. These data suggest that spatial habitat heterogeneity drives hyporheic microbial community development and that attempts to understand functional differences between bacteria inhabiting nutritionally heterogeneous hyporheic environments might begin by focusing on the biology of these taxa.

Computer-assisted lateralization of unilateral temporal lobe epilepsy using Z-score parametric F-18 FDG PET images.

BACKGROUND: To evaluate the use of unbiased computer-assisted lateralization of temporal lobe epilepsy (TLE) by z-score parametric PET imaging (ZPET). METHODS: 38 patients with histologically proven unilateral TLE due to pure hippocampal sclerosis, referred for pre-surgical PET evaluation of intractable seizure over a 5-year period, were included. The F-18 FDG images were oriented along temporal long axis and then transformed into ZPET images on a voxel by voxel basis. Multiple regions of interests (21 in total) were placed on cortical, subcortical and cerebellar structures on twenty-eight out of 38 patients with totally seizure-free (class I) outcome. Paired t-tests with Bonferroni correction were used to determine the location of the most asymmetric regions as variables for subsequent discriminant analysis of the entire group of the patients. RESULTS: The computer program identified the anterior half of the temporal lobe (p < 0.0005) and thalami (p = 0.021) as the most asymmetric regions in TLE patients with Class I outcome. Discriminant analysis using z-scores from a total of 8 ROIs (in 4 pairs) on these structures correctly lateralized thirty-seven out of 38 (97%) patients (sensitivity = 94%; specificity = 100%). The only false localization came from a patient with equivocal z-scores on the temporal lobes and this patient turned out to have poor outcome. CONCLUSION: The computer-assisted lateralization of TLE using ZPET provides an accurate, fast and objective way of seizure evaluation.

Phylogeny of arbuscular mycorrhizal fungi predicts community composition of symbiosis-associated bacteria.

Many physicochemical and biotic aspects of the soil environment determine the community composition of bacteria. In this study, we examined the effects of arbuscular mycorrhizal fungi, common symbionts of higher plants, on the composition of bacterial communities after long-term (7-8 years) enrichment culture in the presence of a plant host. We showed that the phylogeny of arbuscular mycorrhizal fungal isolates was a highly significant predictor of bacterial community composition, as assessed by cluster analysis, redundancy analysis and linear discriminant analysis of phospholipid fatty acid patterns. Numerous phospholipid fatty acids differed between the phylogenetic groupings; this pattern also held for fungal-origin phospholipid fatty acids and in a combined bacterial/fungal analysis, suggesting that categorizing phospholipid fatty acids into predominantly bacterial and fungal origin did not affect the overall outcome. The mechanisms underlying this observation could include substrate quality (and quantity) effects, interactions mediated by the host plant (e.g. rhizodeposition) and direct biotic interactions between arbuscular mycorrhizal fungi and bacterial populations. Our results suggest that aspects of arbuscular mycorrhizal fungal functions may be partially explained by the symbiosis-accompanying bacterial communities, a possibility that should be explicitly considered in studies examining the roles of arbuscular mycorrhizal fungal species diversity in soil and ecosystem processes.

Relationship between communities and processes; new insights from a field study of a contaminated ecosystem.

We used a 93-year-old mine waste contamination gradient in alluvial soil to explore the relationship between ecosystem level functioning and community structure in a chronically stressed ecosystem. The sensitivity of broad functional parameters (in situ soil respiration, microbial biomass, above and below ground plant biomass) and microbial diversity [phospholipid fatty acid (PLFA) abundance and richness] were compared. Functional responses were linear with respect to contaminants while thresholds were detected in the community structural response to contamination along the gradient. For example, in situ soil respiration was negatively and linearly correlated to contamination concentration (R = -0.783, P < 0.01), but changes in microbial community structure only became evident where contaminant concentrations were greater than 28 times above background levels. Our results suggest that functional redundancy does not prevent depression of ecosystem function in the long-term.

Determining rates of change and evaluating group-level resiliency differences in hyporheic microbial communities in response to fluvial heavy-metal deposition.

Prior field studies by our group have demonstrated a relationship between fluvial deposition of heavy metals and hyporheic-zone microbial community structure. Here, we determined the rates of change in hyporheic microbial communities in response to heavy-metal contamination and assessed group-level differences in resiliency in response to heavy metals. A controlled laboratory study was performed using 20 flowthrough river mesocosms and a repeated-measurement factorial design. A single hyporheic microbial community was exposed to five different levels of an environmentally relevant metal treatment (0, 4, 8, 16, and 30% sterilized contaminated sediments). Community-level responses were monitored at 1, 2, 4, 8, and 12 weeks via denaturing gradient gel electrophoresis and quantitative PCR using group-specific primer sets for indigenous populations most closely related to the alpha-, beta-, and gamma-proteobacteria. There was a consistent, strong curvilinear relationship between community composition and heavy-metal contamination (R(2) = 0.83; P < 0.001), which was evident after only 7 days of metal exposure (i.e., short-term response). The abundance of each phylogenetic group was negatively affected by the heavy-metal treatments; however, each group recovered from the metal treatments to a different extent and at a unique rate during the course of the experiment. The structure of hyporheic microbial communities responded rapidly and at contamination levels an order of magnitude lower than those shown to elicit a response in aquatic macroinvertebrate assemblages. These studies indicate that hyporheic microbial communities are a sensitive and useful indicator of heavy-metal contamination in streams.

Seasonal dynamics of shallow-hyporheic-zone microbial community structure along a heavy-metal contamination gradient.

Heavy metals contaminate numerous freshwater streams and rivers worldwide. Previous work by this group demonstrated a relationship between the structure of hyporheic microbial communities and the fluvial deposition of heavy metals along a contamination gradient during the fall season. Seasonal variation has been documented in microbial communities in numerous terrestrial and aquatic environments, including the hyporheic zone. The current study was designed to assess whether relationships between hyporheic microbial community structure and heavy-metal contamination vary seasonally by monitoring community structure along a heavy-metal contamination gradient for more than a year. No relationship between total bacterial abundance and heavy metals was observed (R(2) = 0.02, P = 0.83). However, denaturing gradient gel electrophoresis pattern analysis indicated a strong and consistent linear relationship between the difference in microbial community composition (populations present) and the difference in the heavy metal content of hyporheic sediments throughout the year (R(2) = 0.58, P < 0.001). Correlations between heavy-metal contamination and the abundance of four specific phylogenetic groups (most closely related to the alpha, beta, and gamma-proteobacteria and cyanobacteria) were apparent only during the fall and early winter, when the majority of organic matter is deposited into regional streams. These seasonal data suggest that the abundance of susceptible populations responds to heavy metals primarily during seasons when the potential for growth is highest.

Clear cell tumors have higher mRNA levels of ERCC1 and XPB than other histological types of epithelial ovarian cancer.

PURPOSE: The purpose of the present work was to investigate the relationship between mRNA expression of ERCC1 and XPB, two key genes in the nucleotide excision repair pathway, and clinical resistance of platinum-chemotherapy in histological subtypes of epithelial ovarian cancer. EXPERIMENTAL DESIGN: mRNA levels of ERCC1 and XPB in epithelial ovarian cancer specimens from 126 different individuals were assessed using reverse transcription-PCR and followed by Southern hybridization methodology. Data were analyzed by linear regression analyses and by exhaustive regression analyses. RESULTS: Five different histological types of tumors were examined; serous (n = 76), mucinous (n = 11), clear cell (n = 9), poorly differentiated (n = 9), and endometroid (n = 21). Numerical values for mRNA expression levels were based on internal controls for a stable comparative cell line and for beta-actin. Median values for ERCC1 and XPB mRNAs within clear cell tumors were, on average, >2-fold higher than the other histological tumor types. Linear regression analyses suggest a continuum of nucleotide excision repair gene expression among these cell types, and exhaustive regression analyses demonstrate that the higher mRNA levels seen in clear cell tumors are highly statistically significant. CONCLUSIONS: We conclude that mRNA levels of ERCC1 and XPB tend to be higher in clear cell tumors as opposed to other types of epithelial ovarian cancer. This is consistent with the long-standing observation that clear cell tumors are more likely to show de novo drug resistance against DNA damaging agents in the clinic.