A Severe Case of Spontaneous Intracranial Hypotension in an Adult Asian Male Improved With Trendelenburg Positioning: A Case Report.

Non-traumatic bilateral acute subdural hematomas are a rare occurrence. Etiologies typically include, but are not limited to, cortical artery bleeding, vascular lesions, coagulopathies, and spontaneous intracranial hypotension. We report a case of a 45-year-old Korean male with no known co-morbid illnesses nor history of head or neck trauma, who came to the emergency department due to a 10-day history of dizziness and head heaviness, followed by disorientation and drowsiness. The patient was diagnosed with bilateral acute subdural hematoma; hence, a bilateral posterior parietal craniotomy with evacuation of hematoma was performed. Neurologic status initially improved remarkably; however, during rehabilitation, there was recurrence of acute bilateral subdural hematoma requiring repeat surgical evacuation. There was no clinical improvement after the repeat surgery, and his condition further deteriorated in the neurosciences critical care unit showing signs of rostrocaudal deterioration at the level of diencephalon. A plain cranial CT scan was performed, which showed central herniation and "brain sagging." A diagnosis of spontaneous intracranial hypotension was considered; thus, the patient was managed by positioning him in the Trendelenburg position alternating with flat position on the bed. A search for the cerebrospinal fluid leak was commenced by performing a whole spine MRI constructive interference in steady state (CISS) protocol, which showed a longitudinal spinal anterior epidural cerebrospinal fluid leak from spinal level C2 to T1. Radionuclide cisternography did not provide definitive scintigraphic evidence of a leak. The patient gradually improved and was eventually transferred out of the neurosciences critical care unit. After days of rehabilitation in the hospital, the patient was discharged ambulatory with minimal support.

Synthetic Biomimetic Polymethacrylates: Promising Platform for the Design of Anti-Cyanobacterial and Anti-Algal Agents.

Extensive, uncontrolled growth of algae and cyanobacteria is an environmental, public health, economic, and technical issue in managing natural and engineered water systems. Synthetic biomimetic polymers have been almost exclusively considered antimicrobial alternatives to conventional antibiotics to treat human bacterial infections. Very little is known about their applicability in an aquatic environment. Here, we introduce synthetic biomimetic polymethacrylates (SBPs) as a cost-effective and chemically facile, flexible platform for designing a new type of agent suitable for controlling and mitigating photosynthetic microorganisms. Since SBPs are cationic and membranolytic in heterotrophic bacteria, we hypothesized they could also interact with negatively charged cyanobacterial or algal cell walls and membranes. We demonstrated that SBPs inhibited the growth of aquatic photosynthetic organisms of concern, i.e., cyanobacteria (Microcystis aeruginosa and Synechococcus elongatus) and green algae (Chlamydomonas reinhardtii and Desmodesmus quadricauda), with 50% effective growth-inhibiting concentrations ranging between 95 nM and 6.5 µM. Additionally, SBPs exhibited algicidal effects on C. reinhardtii and cyanocidal effects on picocyanobacterium S. elongatus and microcystin-producing cyanobacterium M. aeruginosa. SBP copolymers, particularly those with moderate hydrophobic content, induced more potent cyanostatic and cyanocidal effects than homopolymers. Thus, biomimetic polymers are a promising platform for the design of anti-cyanobacterial and anti-algal agents for water treatment.

Author Correction: Anticancer polymers designed for killing dormant prostate cancer cells.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Use of Response Surface Methodology To Develop and Optimize the Composition of a Chitosan-Polyethyleneimine-Graphene Oxide Nanocomposite Membrane Coating To More Effectively Remove Cr(VI) and Cu(II) from Water.

Response surface methodology was successfully used to optimize the amounts of chitosan (CS), polyethyleneimine (PEI), graphene oxide (GO), and glutaraldehyde (GLA) to produce a multifunctional nanocomposite membrane coating able to remove positively and negatively charged heavy metals, such as Cr(VI) and Cu(II). Batch experiments with different concentrations of the four coating components (GO, CS, PEI, and GLA) on cellulose membranes were carried out with solutions containing 10 ppm Cr(VI) and Cu(II) ions. Reduced quadratic equations for the Cr(VI) and Cu(II) removal were obtained based on the observed results of the batch experiments. The numerical analysis resulted in an optimized solution of soaking for 30 min in CS, 1.95% PEI, 1000 ppm GO, and 1.68% GLA with predicted removal of 90 ± 10 and 30 ± 3% for Cr(VI) and Cu(II), respectively, with a desirability of 0.99. This mathematically optimized solution for the coating was experimentally validated. To determine the best membrane material for the coating, stability of the nanocomposite coating was determined using attenuated total reflectance-infrared spectroscopy in eight membrane materials before and after exposure to four solutions with different water chemistries. The glass microfiber (GMF) membranes were determined to be one of the best materials to receive the coating. Then, the coated GMF filter was further investigated for the removal of Cr(VI) and Cu(II) in single and binary component solutions. The results showed that the coatings were able to remove successfully both heavy metal ions, suggesting its ability to remove positively and negatively charged ions from water.

Anticancer polymers designed for killing dormant prostate cancer cells.

The discovery of anticancer therapeutics effective in eliminating dormant cells is a significant challenge in cancer biology. Here, we describe new synthetic polymer-based anticancer agents that mimic the mode of action of anticancer peptides. These anticancer polymers developed here are designed to capture the cationic, amphiphilic traits of anticancer peptides. The anticancer polymers are designed to target anionic lipids exposed on the cancer cell surfaces and act by disrupting the cancer cell membranes. Because the polymer mechanism is not dependent on cell proliferation, we hypothesized that the polymers were active against dormant cancer cells. The polymers exhibited cytotoxicity to proliferating prostate cancer. Importantly, the polymer killed dormant prostate cancer cells that were resistant to docetaxel. This study demonstrates a new approach to discover novel anticancer therapeutics.

A morphological, enzymatic and metabolic approach to elucidate apoptotic-like cell death in fungi exposed to h- and α-molybdenum trioxide nanoparticles.

The present study compares for the first time the effects of h-MoO3 and α-MoO3 against two fungal strains: Aspergillus niger and Aspergillus flavus. The h-MoO3 nanoparticles were more toxic to both fungi than α-MoO3. The toxic effects of h-MoO3 were more pronounced toward A. flavus, which presented a growth inhibition of 67.4% at 200 mg L-1. The presence of the nanoparticles affected drastically the hyphae morphology by triggering nuclear condensation and compromising the hyphae membrane. Further analysis of the volatile organic compounds (VOCs) produced by both fungi in the presence of the nanomaterials indicated important metabolic changes related to programmed cell death. These nanomaterials induced the production of specific antifungal VOCs, such as ß-Elemene and t-Cadinol, by the fungi. The production of essential enzymes involved in fungal metabolism, such as acid phosphatase, naphthol-As-BI-phosphohydrolase, ß-galactosidase, ß-glucosidase and N-acetyl-ß-glucosaminidase, reduced significantly in the presence of the nanomaterials. The changes in enzymatic production and VOCs corroborate the fact that these nanoparticles, especially h-MoO3, exert changes in the fungal metabolism, triggering apoptotic-like cell death responses in these fungi.

A Cationic Amphiphilic Random Copolymer with pH-Responsive Activity against Methicillin-Resistant Staphylococcus aureus.

In this report, we demonstrate the pH-dependent, in vitro antimicrobial activity of a cationic, amphiphilic random copolymer against clinical isolates of drug-resistant Staphylococcus aureus. The polymer was developed toward a long-term goal of potential utility in the treatment of skin infections. The proposed mechanism of action of the polymer is through selectively binding to bacterial membranes and subsequent disruption of the membrane structure/integrity, ultimately resulting in bacterial cell death. The polymer showed bactericidal activity against clinical isolates of methicillin-resistant or vancomycin-intermediate S. aureus. The polymer was effective in killing S. aureus at neutral pH, but inactive under acidic conditions (pH 5.5). The polymer did not exhibit any significant hemolytic activity against human red blood cells or display cytotoxicity to human dermal fibroblasts over a range of pH values (5.5-7.4). These results indicate that the polymer activity was selective against bacteria over human cells. Using this polymer, we propose a new potential strategy for treatment of skin infections using the pH-sensitive antimicrobial polymer agent that would selectively target infections at pH-neutral wound sites, but not the acidic, healthy skin.

Cationic Amphiphilic Polymers with Antimicrobial Activity for Oral Care Applications: Eradication of S. mutans Biofilm.

The antibacterial and antibiofilm activities of cationic amphiphilic methacrylate polymers against cariogenic bacterium S. mutans were investigated. Cationic homopolymer PE0 and copolymer PE31 containing 31 mol % of ethyl methacrylate were synthesized by reversible addition-fragmentation chain transfer polymerization. These polymers displayed bactericidal activity toward S. mutans and prevented biofilm formation by killing the planktonic bacteria. At a concentration of 1000 µg/mL when incubated for 2 h the polymers reduced >80% of biofilm biomass. When the polymer assay solution with the biofilm was vigorously mixed using a pipet for 30 s, >50% of biofilm mass was removed at a polymer concentration of 250 µg/mL. Chlorhexidine and a cationic surfactant failed to reduce the biofilm mass at the same concentration. PE0 was the most effective in removing biofilm and did not show any significant cytotoxicity to human gingival fibroblast and periodontal ligament stem cells when incubated for 10 min.

Designing polymeric adhesives for antimicrobial materials: poly(ethylene imine) polymer, graphene, graphene oxide and molybdenum trioxide - a biomimetic approach.

The synthesis of biocompatible polymers for coating applications has gained significant attention in recent years due to the increasing spread of infectious diseases via contaminated surfaces. One strategy to combat this problem is to apply antimicrobial coatings to surfaces prone to microbial contamination. This study presents a series of biomimetic polymers that can be used as adhesives to immobilize known antimicrobial agents on the surfaces as coatings. Several polymers containing dopamine methacrylate as co-polymers were synthesized and investigated as adhesives for the deposition of an antimicrobial polymer (polyethyleneimine) and antimicrobial nanoparticles (graphene, graphene oxide and molybdenum trioxide) onto glass surfaces. The results showed that different antimicrobials required different types of adhesives for effective coating. Overall, the coatings fabricated from these composites were shown to inactivate E. coli and B. subtilis within 1 h. These coatings were also effective to prevent biofilm growth and demonstrated to be non-toxic to the human corneal epithelial cell line (htCEpi). Leaching tests of the coatings proved that the coatings were stable under biological conditions.

Scope and limitations of auxiliary-assisted, palladium-catalyzed arylation and alkylation of sp2 and sp3 C-H bonds.

The scope of palladium-catalyzed, auxiliary-assisted direct arylation and alkylation of sp(2) and sp(3) C-H bonds of amine and carboxylic acid derivatives has been investigated. The method employs a palladium acetate catalyst, substrate, aryl, alkyl, benzyl, or allyl halide, and inorganic base in tert-amyl alcohol or water solvent at 100-140 °C. Aryl and alkyl iodides as well as benzyl and allyl bromides are competent reagents in this transformation. The picolinic acid auxiliary is used for amine γ-functionalization, and the 8-aminoquinoline auxiliary is used for carboxylic acid ß-functionalization. Some optimization of base, additives, and solvent is required for achieving best results.

Heterocycle synthesis via direct C-H/N-H coupling.

A method for five- and six-membered heterocycle formation by palladium-catalyzed C-H/N-H coupling is presented. The method employs a picolinamide directing group, PhI(OAc)(2) oxidant, and toluene solvent at 80-120 °C. Cyclization is effective for sp(2) as well as aliphatic and benzylic sp(3) C-H bonds.

Palladium-catalyzed indole, pyrrole, and furan arylation by aryl chlorides.

The palladium-catalyzed direct arylation of indoles, pyrroles, and furans by aryl chlorides has been demonstrated. The method employs a palladium acetate catalyst, 2-(dicyclohexylphosphino)-biphenyl ligand, and an inorganic base. Electron-rich and electron-poor aryl chlorides as well as chloropyridine coupling partners can be used, and arylated heterocycles are obtained in moderate to good yields. Optimization of base, ligand, and solvent is required for achieving best results.

Mandatory celiotomy for penetrating abdominal stab wounds: An analysis of 483 cases

It has been suggested in a number of studies that penetrating abdominal stab wounds may be managed conservatively although only a few local studies support this claim. This study reviews experience based on 483 patients, who underwent celiotomy for a single penetrating abdominal stab wound inflicted by a single bladed knife from Jan. 1989 to June 1991. The cases were divided into two (2) groups, those who underwent celiotomy with indications and those who underwent celiotomy without indications. Tabulation of operative findings according to the location of the stab wound in the nine (9) regions of the anterior abdomen showed that 89% of all patients with indications for surgery had significant injury. In the group who underwent celiotomy without indications, 78% had positive findings. The data for groups A and B stratified into the nine regions did not show any significant difference in the frequency of abdominal injury except in the right lumbar, left lumbar, left iliac and umbilical region. In these last four regions, the frequency of abdominal injury in the group with indications is statistically higher than in the group without indications. Therefore, a trial of observation in these regions is therefore acceptable in the absence of indications for celiotomy.

The diabetic foot: An analysis of predictive factors for amputation

A retrospective study was undertaken on 103 diabetic patients with foot ulcers who were confined at the UERM Memorial Medical Center from January 1988 to June 1991 with the aim of determining clinical and laboratory criteria which are useful in predicting the need for amputation. Patients were divided into two groups according to treatment modality: Group A, debridement (58 patients) and Group B, amputation (45 patients). Nineteen variables chosen from the patients demographic characteristics, clinical histories and evaluation, and laboratory work-up were reviewed, evaluated, and processed using the normal approximation statistics and logistic regression to obtain a resulting set of predictors. Osteomyelitis, leukocytosis, decreased or absent peripheral pulses, systolic hypertension and smoking history were the five variables found to be significantly associated with the need for an ablative surgical procedure. These quantitated variables are entered into the computed logistic equation to obtain a score which will enable us to determine the appropriate therapeutic intervention tailored to the individuals risk status. If the computed value is greater than or equal to 7, amputation should be the course of action. If the computed value is less than or equal to 3, conservative treatment is advocated. If the value obtained is between 3 and 7, the patient is considered a borderline case and proper management will have to depend on the judgment of the surgeon. With this scoring system as a guide, a definitive operation can be performed at an early stage to prevent the burden of multiple operations and the accompanying high morbidity and post-operative mortality rates.