Locally invasive recurrence or metastasis of pheochromocytoma into the liver?-clinicopathological challenges.

Pheochromocytomas (PCC) are rare and functional neuroendocrine tumors developing from adrenal chromaffin cells. Predicting malignant behavior especially in the absence of metastasis can be quite challenging even in the era of improved understanding of the molecular mechanisms involved in PCCs. Currently, two histopathological grading systems Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) and Grading of Adrenal Pheochromocytoma and Paraganglioma (GAPP) score are used in clinical practice, but these are subject to significant interobserver variability. Some of the most useful clinical factors associated with malignancy are large size ([4-5 cm), and genetic features such as presence of SDHB germline mutations. Local invasion is uncommon in PCC and metastasis seen in 10 to 17% but higher in germline mutations and when this occurs management can be challenging. Here, we report on a case with challenges faced by the pathologist and clinicians alike in diagnosis and management of PCC recurrence.

Biochar-surface oxygenation with hydrogen peroxide.

Biochar was produced from pinewood biomass by pyrolysis at a highest treatment temperature (HTT) of 400 °C. This biochar was then treated with varying concentrations of H2O2 solution (1, 3, 10, 20, 30% w/w) for a partial oxygenation study. The biochar samples, both treated and untreated, were then tested with a cation exchange capacity (CEC) assay, Fourier Transformed Infrared Resonance (FT-IR), elemental analysis, field water-retention capacity assay, pH assay, and analyzed for their capacity to remove methylene blue from solution. The results demonstrated that higher H2O2 concentration treatments led to higher CEC due to the addition of acidic oxygen functional groups on the surface of the biochar, which also corresponds to the resultant lowering of the pH of the biochar with respect to the H2O2 treatment. Furthermore, it was shown that the biochar methylene blue adsorption decreased with higher H2O2 concentration treatments. This is believed to be due to the addition of oxygen groups onto the aromatic ring structure of the biochar which in turn weakens the overall dispersive forces of π-π interactions that are mainly responsible for the adsorption of the dye onto the surface of the biochar. Elemental analysis revealed that there was no general augmentation of the elemental composition of the biochar samples through the treatment with H2O2, which suggests that the bulk property of biochar remains unchanged through the treatment.

Comparative analysis of pinewood, peanut shell, and bamboo biomass derived biochars produced via hydrothermal conversion and pyrolysis.

Biochars were produced from pinewood, peanut shell, and bamboo biomass through hydrothermal conversion (HTC) at 300 °C and comparatively by slow pyrolysis over a temperature range of 300, 400, and 500 °C. These biochars were characterized by FT-IR, cation exchange capacity (CEC) assay, methylene blue adsorption, as well as proximate and elemental analysis. The experimental results demonstrated higher retained oxygen content in biochars produced at lower pyrolysis temperatures and through HTC, which also correlated to the higher CEC of respective biochars. Furthermore, all types of biochar studied herein were capable of adsorption of methylene blue from solution and the adsorption did not appear to strongly correlate with CEC, indicating that the methylene blue adsorption appears to be dependent more upon the non-electrostatic molecular interactions such as the likely dispersive π-π interactions between the graphene-like sheets of the biochar with the aromatic ring structure of the dye, than the electrostatic CEC. A direct comparison of hydrothermal and pyrolysis converted biochars reveals that biochars produced through HTC have much higher CEC than the biochars produced by slow pyrolysis. Analysis by FT-IR reveals a higher retention of oxygen functional groups in HTC biochars; additionally, there is an apparent trend of increasing aromaticity of the pyrolysis biochars when produced at higher temperatures. The CEC value of the HTC biochar appears correlated with its oxygen functional group content as indicated by the FT-IR measurements and its O:C ratio.

Molecular characterization of inhibiting biochar water-extractable substances using electrospray ionization fourier transform ion cyclotron resonance mass spectrometry.

Biochar has gained significant interest worldwide for its potential use as both a carbon sequestration technique and soil amendment. Recently, research has shown that pinewood-derived biochar water extracts inhibited the growth of aquatic photosynthetic microorganisms, both prokaryotic and eukaryotic algae, while chicken litter- and peanut shell-derived biochar water extracts showed no growth inhibition. With the use of electrodialysis, the pinewood-derived biochar water extract is separated into 3 fractions (anode-isolated, center chamber retained, and cathode-isolated substances) all with varying toxic effects. Because of its ultrahigh resolution and mass precision, electrospray ionization (ESI) coupled to Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) is utilized in this study to analyze biochar water extracts at a molecular level to enhance our understanding of the toxic nature of pinewood-derived biochar water extracts as compared to benign peanut shell-derived biochar water extracts. The molecular composition of pinewood-derived biochar water extracts shows unique carbohydrate ligneous components and sulfur containing condensed ligneous components that are both absent from the peanut shell water extracts and more prevalent in the anode-isolated substances. Using Kendrick mass defect analysis, we also determine that the most likely inhibitor species contain carboxyl and hydroxyl homologous series, both of which are characteristic functional groups hypothesized in our previous research for the inhibitor species. We have suggested that inhibition of aquatic photosynthetic microorganism growth is most likely due to degraded lignin-like species rich in oxygen containing functionalities. From the study conducted here, we show the potential of ultrahigh resolution FTICR-MS as a valuable analytical technique for determining whether certain biochars are safe and benign for use as carbon sequestration and soil amendment.

Primary Peritonitis Secondary to Streptococcus pyogenes in a Young Female Adult-A Case Report and Literature Review.

Primary spontaneous bacterial peritonitis (SBP) is a rare cause of acute abdomen in previously healthy patients, even more unusually caused by a group A Streptococcus (GAS) (also known as Streptococcus pyogenes) infection. We report a young, otherwise healthy female who presented with generalized abdominal pain that was initially managed conservatively as gastroenteritis, with a computed tomography (CT) scan showing a ruptured corpus luteal cyst. Upon subsequent readmission with worsened pain and symptoms, a repeat CT scan showed worsened free fluid with signs of peritonitis. A diagnostic laparoscopy confirmed primary peritonitis with an unknown infection source and causative pathology, as the appendix, ovaries and bowels were healthy-looking. Fluid cultures returned positive for GAS Pyogenes, while blood and urine cultures were negative. The discussion reviews the challenges in diagnosis and treatment of GAS primary peritonitis, highlighting the need for clinical suspicion, early diagnosis via laparoscopy or laparotomy and prompt antibiotic therapy as the current standard for treatment.

Longitudinal versus transverse incision for common femoral artery exposure: a systematic review and meta-analysis.

BACKGROUND: A longitudinal or a transverse incision is routinely used for common femoral artery (CFA) exposure. Some believe a transverse incision is associated with a lower incidence of postoperative complications. We performed a systematic review and meta-analysis to evaluate the risk of postoperative surgical site infection, lymphatic complications, wound dehiscence and haematoma formation when using a longitudinal or transverse incision for CFA exposure. METHODS: Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were adhered to. We searched various databases such as MEDLINE via PubMed and Embase for relevant studies from inception till 31 May 2020. Relevant search terms such as 'longitudinal', 'transverse', 'vertical', 'horizontal', 'femoral', 'incision' were used. We included both randomized controlled trials and case-controlled studies, and extracted data related to study characteristics and postoperative complications. We assessed risk of bias using the Cochrane risk of bias tool and the Newcastle-Ottawa scale. A random-effects meta-analysis was performed to obtain the pooled proportions and risk ratios (RR) for our study outcomes. RESULTS: We included seven studies with a total of 5922 groin incisions. A longitudinal incision was associated with a significantly higher incidence of wound infection (RR 2.93, 95% confidence interval (CI) 1.12-7.70, P = 0.03) and wound dehiscence (RR 2.87, 95% CI 1.06-7.77, P = 0.04). The risk of lymphatic complications (RR 1.09, 95% CI 0.39-3.05, P = 0.87) and wound haematoma (RR 2.85, 95% CI 0.88-9.21, P = 0.08) were similar. CONCLUSIONS: A longitudinal incision may be associated with a higher incidence of wound infection and wound dehiscence, as compared to using a transverse incision for CFA exposure.

Characterization of biochars produced from cornstovers for soil amendment.

Through cation exchange capacity assay, nitrogen adsorption-desorption surface area measurements, scanning electron microscopic imaging, infrared spectra and elemental analyses, we characterized biochar materials produced from cornstover under two different pyrolysis conditions, fast pyrolysis at 450 °C and gasification at 700 °C. Our experimental results showed that the cation exchange capacity (CEC) of the fast-pyrolytic char is about twice as high as that of the gasification char as well as that of a standard soil sample. The CEC values correlate well with the increase in the ratios of the oxygen atoms to the carbon atoms (O:C ratios) in the biochar materials. The higher O:C ratio was consistent with the presence of more hydroxyl, carboxylate, and carbonyl groups in the fast pyrolysis char. These results show how control of biomass pyrolysis conditions can improve biochar properties for soil amendment and carbon sequestration. Since the CEC of the fast-pyrolytic cornstover char can be about double that of a standard soil sample, this type of biochar products would be suitable for improvement of soil properties such as CEC, and at the same time, can serve as a carbon sequestration agent.

Survivability of Wild-Type and Genetically Engineered Thermosynechococcus elongatus BP1 with Different Temperature Conditions.

Introduction: Thermosynechococcus elongatus BP1 is a thermophilic strain of cyanobacteria that has an optimum growth at 57°C, and according to previous analysis by Yamaoka et al, T elongatus BP1 cannot survive at a temperature below 30°C. This suggests that the thermophilic property of this strain may be used as a natural biosafety feature to limit the spread of genetically engineered (GE) organisms in the environment if physical containment fails. Objective: To further explore the growth and survivability range of T elongatus BP1, we report a growth and survivability assay of wild-type and GE T elongatus BP1 strains under different conditions. Methods: Wild-type and GE T elongatus BP1 cultures were prepared and incubated in the laboratory (high temperatures and constant light source) and greenhouse conditions (lower/varied temperatures and sunlight) for 4 weeks. The cell density was monitored weekly by measuring the optical density at 730 nm (OD730). To assess the survivability, a sample of each culture was added to fresh media, placed in laboratory conditions (42.2°C and 30 µE m-2 s-1) in multi-well plates and observed for growth for up to three weeks. Lastly, the number of viable cells were determined by plating a diluted sample of the culture on solid media and counting colony-forming units (CFU) after 1 day, 2 weeks and 4 weeks of incubation in laboratory or greenhouse conditions. Results: Our experimental results demonstrated that growth was hindered but that the cells did not entirely die within 2 to 4 weeks at warm temperatures (31.42°C-36.27°C). The study also showed that 2 weeks of exposure to cool temperature conditions (15.44°C-25.30°C) was enough to cause complete death of GE T elongatus BP1. However, it took 2 to 4 weeks for the wild-type T elongatus BP1 cells to die. Conclusion: This study revealed that the thermophilic feature of the T elongatus BP1 may be used as an effective biosafety mechanism at a cool temperature between 15.44°C and 25.30°C but may not be able to serve as a biosafety mechanism at warmer temperatures.

Evaluation of outpatient cystoscopy in urogynaecology.

OBJECTIVE: Prospective evaluation of outpatient cystoscopy in a Urogynaecology Unit. DESIGN: Prospective observational series. SETTING: St. George's Hospital, London. Department of Pelvic Reconstructive Surgery and Urogynaecology. POPULATION: A total of 131 consecutive women, who underwent outpatient rigid cystoscopy over a 24-month-period. MATERIALS AND METHODS: Prospective data collection included cystoscopic findings, microbiology data, uroflowmetry and radiological results. An Immediate Feedback Questionnaire was completed at the end of the procedure. MAIN OUTCOME MEASURES: Success rates of the procedure, cystoscopy findings, requirements for additional investigations, including inpatient cystoscopy and patient satisfaction rates. RESULTS: The mean age was 56.4 years (range 20-87 years). A total 126 women (96.2%) had a successful outpatient cystoscopy. In five (3.8%) women the procedure had to be abandoned because of inability to insert the cystoscope. Eleven women (8.7%) experienced pain but were able to tolerate the discomfort. Fifty-three (42.7%) women had abnormalities detected at cystoscopy. Thirty-seven women had trabeculations. Focal vesical lesions were found in 21 women. Thirty-nine (30.9%) women did not require any additional treatment. Six (6.9%) women were scheduled for repeat cystoscopy under general anaesthetic to facilitate a bladder biopsy. Fifteen women (17.2%) were referred for urodynamics or renal imaging. Three women (3.4%) were referred to a urologist. More than 75% reported high satisfaction with the care they received. Four women had symptoms of UTI and two had positive urinary cultures and required antibiotics. CONCLUSIONS: The benefits of outpatient cystoscopy include high levels of tolerability and patient satisfaction, shorter waiting time, quicker implementation of treatment strategies, avoidance of the risks of general anaesthesia and lower procedural cost.

Demonstration of horizontal gene transfer from genetically engineered Thermosynechococcus elongatus BP1 to wild-type E. coli DH5α.

Synthetic biology with genetically engineered (GE) cyanobacteria has the potential to produce valuable products such as biofuels. However, it is also essential to assess the potential risks of synthetic biology technology before it can be widely used. In order to address key concerns posed by the application of synthetic biology to microorganisms, studies were designed to monitor the horizontal transfer of engineered genes from GE cyanobacteria Thermosynechococcus elongatus BP1 to Escherichia coli through co-incubation. The results of these experiments demonstrated that the genetically engineered DNA construct containing alcohol producing genes and kanamycin resistance can be horizontally transferred from GE T. elongatus BP1 to wild-type E. coli following two days of liquid co-culturing. The rapid and facile transfer of foreign genes, which include antibiotic resistance, between bacterial communities signifies the need to continue to deepen our understanding of the process of horizontal gene transfer, chromosomal integration as well as further biosafety-oriented research efforts. In the era of synthetic biology, the natural microbial process for sharing genetic material will also significantly impact risk assessments, containment approaches and further policy development.

Imaging nanometer metallocatalysts formed by photosynthetic deposition of water-soluble transition-metal compounds.

A method of imaging nanometer metallocatalysts formed by photosynthetic precipitation of the water-soluble transition-metal compounds [PtCl(6)](2-) and [RuCl(6)](2-) is reported. Hexachloroplatinate and hexachlororuthenate can accept up to four electrons from Photosystem I (PSI) reaction centers in photosynthetic thylakoid membranes, thereby converting [PtCl(6)](2-) and [RuCl(6)](2-) anions to either metallic platinum (Pt) and ruthenium (Ru) and/or partially oxidized nanometer catalysts at the reducing sides of PSI molecules. Use of this method can potentially create nanometer-sized Pt and/or bimetallic catalysts (such as Pt-Ru) on biomembranes and molecules at pH 7 and room temperature with preservation of the biological function of the molecules.

Female urethral diverticula.

Urethral diverticula are frequently under-diagnosed. The pathogenesis of this condition is poorly understood, and these lesions represent a spectrum of disorders ranging from isolated suburethral cysts to herniation of the urethral lining into the vaginal mucosa. Women with this disorder frequently complain of a host of symptoms referable to the lower urinary and genital tracts. Accurate diagnosis is based on history and clinical evaluation. Perineal ultrasound and MRI are often helpful. Repeated courses of antibiotics and urethral dilatation often fail to resolve the problem, and definitive intervention usually requires surgical excision to provide relief. This chapter describes the current management of this condition, and it heralds a re-look at the patho-aetiology in view of recent MRI findings of symptomatic non-communicating microcystic lesions.

A new oxygen sensitivity and its potential application in photosynthetic H2 production.

We have discovered a new competitive pathway for O2 sensitivity in algal H2 production that is distinct from the O2 sensitivity of hydrogenase per se. This O2 sensitivity is apparently linked to the photosynthetic H2 production pathway that is coupled to proton translocation across the thylakoid membrane. Addition of the proton uncoupler carbonyl cyanide-p-trifluoromethoxy- phenylhydrazone eliminates this mode of O2 inhibition on H2 photoevolution. This newly discovered inhibition is most likely owing to background O2 that apparently serves as a terminal electron acceptor in competition with the H2 production pathway for photosynthetically generated electrons from water splitting. This O2-sensitive H2 production electron transport pathway was inhibited by 3[3,4-dichlorophenyl]1,1-dimethylurea. Our experiments demonstrated that this new pathway is more sensitive to O2 than the traditionally known O2 sensitivity of hydrogenase. This discovery provides new insight into the mechanism of O2 inactivation of hydrogenase and may contribute to the development of a more-efficient and robust system for photosynthetic H2 production.

Improvement of photosynthetic CO2 fixation at high light intensity through reduction of chlorophyll antenna size.

At elevated light intensities (greater than approximately 200 microE/[m2 x s]), the kinetic imbalance between the rate of photon excitation and thermally activated electron transport results in saturation of the rate of photosynthesis. Since maximum terrestrial solar radiation can reach 200 microE/(m2 x s), a significant opportunity exists to improve photosynthetic efficiency at elevated light intensities by achieving a kinetic balance between photon excitation and electron transport, especially in designed large-scale photosynthetic reactors in which a low-cost and efficient biomass production system is desired. One such strategy is a reduction in chlorophyll (chl) antenna size in relation to the reaction center that it serves. In this article, we report recent progress in this area of research. Light-saturation studies for CO2 fixation were performed on an antenna-deficient mutant of Chlamydomonas (DS521) and the wild type (DES15) with 700 ppm of CO2 in air. The light-saturated rate for CO2 assimilation in the mutant DS521 was about two times higher (187 micromol/[h x mg of chl]) than that of the wild type, DES15 (95 micromol/[h x mg of chl]). Significantly, a partial linearization of the light-saturation curve was also observed. These results confirmed that DS521 has a smaller relative chl antenna size and demonstrated that reduction of relative antenna size can improve the overall efficiency of photon utilization at higher light intensities. The antenna-deficient mutant DS521 can provide significant resistance to photoinhibition, in addition to improvement in the overall efficiency of CO2 fixation at high light. The experimental data reported herein support the idea that reduction in chl antenna size could have significant implications for both fundamental understanding of photosynthesis and potential application to improve photosynthetic CO2 fixation efficiency.

A modified technique for the surgical correction of urethral diverticula using a porcine xenograft.

We report a case of urethral diverticulectomy re-enforced with a porcine xenograft to prevent the risk of recurrence or fistula in the presence of a large urethral communication. The use of porcine small intestinal submucosal xenograft (SIS, Surgisis, Cook, Ireland) material has a low graft rejection rate and erosion is rare as the material is degraded after 3 to 6 months. In this case, xenograft achieved tension-free closure of the urethral defect without any postoperative complications.

Is Doppler planimetry a valid technique for the evaluation of postpartum urinary bladder volume?

The objective of this prospective study was to evaluate the accuracy of conventional 2D ultrasound (CUS) versus doppler planimetry (DP) in the assessment of postpartum urinary bladder volume compared to a true estimate using urethral catheterisation. Fifty-two women were assessed within 24 hours of delivery. Evaluation of bladder volume was performed using CUS (1-estimate) and DP (6-estimates). CUS had a higher correlation (r=0.796) with the true volume and lower % error than DP in the postpartum group. DP readings were highly reproducible (ICC 0.81) but tended to overestimate the true value especially with smaller volumes. DP was suboptimal for the assessment of the postpartum PVR. Postpartum evaluation using CUS is more accurate in calculating the true urinary volume.

Single-strand DNA molecule translocation through nanoelectrode gaps.

Molecular dynamics simulations were performed to investigate the translocation of single-strand DNA through nanoscale electrode gaps under the action of a constant driving force. The application behind this theoretical study is a proposal to use nanoelectrodes as a screening gap as part of a rapid genomic sequencing device. Preliminary results from a series of simulations using various gap widths and driving forces suggest that the narrowest electrode gap that a single-strand DNA can pass is ∼1.5 nm. The minimum force required to initiate the translocation within nanoseconds is ∼0.3 nN. Simulations using DNA segments of various lengths indicate that the minimum initiation force is insensitive to the length of DNA. However, the average threading velocity of DNA varies appreciably from short to long DNA segments. We attribute such variation to the different nature of drag force experienced by the short and long DNA segments in the environment. It is found that DNA molecules deform significantly to fit in the shape of the nanogap during the translocation.

Rapid toluidine blue stain for Mohs' micrographic surgery.

BACKGROUND: Toluidine blue is a useful stain for detecting basal cell carcinoma during Mohs' micrographic surgery. OBJECTIVE: To demonstrate the efficacy of alkalinization on the toluidine blue stain. METHODS: A 1% aqueous toluidine blue-1% aqueous sodium borate solution was used to stain microscope slides for basal cell carcinoma during Mohs' micrographic surgery. RESULTS: Total toluidine blue staining time was reduced to less than 2.5 minutes, without compromising the quality of the stain. CONCLUSIONS: The rapid toluidine blue stain reduces staining time while maintaining staining quality, including the advantages specific to the toluidine blue stain.