A biomimetic camouflaged metal organic framework for enhanced siRNA delivery in the tumor environment

Gene silencing through RNA interference (RNAi), particularly using small double-stranded RNA (siRNA), has been identified as a potent strategy for targeted cancer treatment. Yet, its application faces challenges such as nuclease degradation, inefficient cellular uptake, endosomal entrapment, off-target effects, and immune responses, which have hindered its effective delivery. In the past few years, these challenges have been addressed significantly by using camouflaged metal-organic framework (MOF) nanocarriers. These nanocarriers protect siRNA from degradation, enhance cellular uptake, and reduce unintended side effects by effectively targeting desired cells while evading immune detection. By combining the properties of biomimetic membranes and MOFs, these nanocarriers offer superior benefits such as extended circulation times, enhanced stability, and reduced immune responses. Moreover, through ligand-receptor interactions, biomimetic membrane-coated MOFs achieve homologous targeting, minimizing off-target adverse effects. The MOFs, acting as the core, efficiently encapsulate and protect siRNA molecules, while the biomimetic membrane-coated surface provides homologous targeting, further increasing the precision of siRNA delivery to cancer cells. In particular, the biomimetic membranes help to shield the MOFs from the immune system, avoiding unwanted immune responses and improving their biocompatibility. The combination of siRNA with innovative nanocarriers, such as camouflaged-MOFs, presents a significant advancement in cancer therapy. The ability to deliver siRNA with precision and effectiveness using these camouflaged nanocarriers holds great promise for achieving more personalized and efficient cancer treatments in the future. This review article discusses the significant progress made in the development of siRNA therapeutics for cancer, focusing on their effective delivery through novel nanocarriers, with a particular emphasis on the role of metal-organic frameworks (MOFs) as camouflaged nanocarriers.

Tailoring Bi2Se3 Topological Insulator for Visible-NIR Photodetectors with Schottky Contacts Using Liquid Phase Exfoliation

Layered semiconductors of the V-VI group have attracted considerable attention in optoelectronic applications owing to their atomically thin structures. They offer thickness-dependent optical and electronic properties, promising ultrafast response time, and high sensitivity. Compared to the bulk, 2D bismuth selenide (Bi2Se3) is recently considered a highly promising material. In this study, 2D nanosheets are synthesized by prolonged sonication in two different solvents, such as N-methyl-2-pyrrolidone (NMP) and chitosan-acetic acid solution (CS-HAc), using the liquid-phase exfoliation (LPE) method. X-ray diffraction confirms the amorphous nature of exfoliated 2D nanosheets with maximum peak intensity at the same position (015) crystal plane as that obtained in its bulk counterpart. SEM confirms the thin 2D nanosheet-like morphology. Successful exfoliation of Bi2Se3 nanosheets up to five layers is achieved using CS-HAc solvent. The as-synthesized 2D nanosheets in different solvents are employed to fabricate the photodetector. At minimum selected power density, the photodetector fabricated using exfoliated ultrathin 2D nanosheets exhibits the highest range of responsivity, varying from 15 to 2.5 mA/W, and detectivity ranging from 2.83 × 109 to 6.37 × 107. Ultrathin 2D Bi2Se3 nanosheets have fast rise and fall times, ranging from 0.01 to 0.12 and 0.01 to 0.06 s, respectively, at different wavelengths. Ultrathin Bi2Se3 nanosheets have improved photodetection parameters as compared to multilayered nanosheets due to the high surface to volume ratio, reduced recombination and trapping of charge carrier, improved carrier confinement, and faster carrier transport due to the thin layer.

Hierarchical-Bioinspired MOFs Enhanced Electromagnetic Wave Absorption

Proteins exhibit complex and diverse multi-dimensional structures, along with a wide range of functional groups capable of binding metal ions. By harnessing the unique characteristics of proteins, it is possible to enhance the synthesis of metal-organic frameworks (MOFs) and modify their morphology. Here, the utilization of biomineralized bovine serum albumin (BSA) protein as a template for synthesizing Mil-100 with superior microwave absorption (MA) properties is investigated. The multi-dimensional structure and abundant functional groups of biomineralized BSA protein make it an ideal candidate for guiding the synthesis of Mil-100 with intricate network structures. The BSA@Mil-100 synthesized using this method exhibits exceptional uniformity and monodispersity of nanocrystals. The findings suggest that the BSA protein template significantly influences the regulation of nanocrystal and microstructure formation of Mil-100, resulting in a highly uniform and monodisperse structure. Notably, the synthesized 2-BSA@Mil-100 demonstrates a high reflection loss value of -58 dB at 8.85 GHz, along with a maximum effective absorption bandwidth value of 6.79 GHz, spanning from 6.01 to 12.8 GHz. Overall, this study highlights the potential of utilizing BSA protein as a template for MOF synthesis, offering an effective strategy for the design and development of high-performance MA materials.

Scale and Safety: Analyzing the Association Between Intraoperative Difficulty and Achieving the Critical View of Safety in Laparoscopic Cholecystectomy

BACKGROUND

 Laparoscopic cholecystectomy (LC) is the preferred method for gallstone removal, but bile duct injuries remain a concern. Achieving the critical view of safety (CVS) is pivotal in preventing such injuries. The aim of this study was to compare the rates of difficult LC in those with CVS achieved compared to those with CVS not achieved.

METHODS

We performed a single-center prospective study on all patients with ultrasound-confirmed symptomatic gallstones. Patients were excluded if they refused to consent or if they underwent LC for indications other than gallstone disease. Patients were stratified into two groups as CVS not achieved and CVS achieved groups and compared for outcomes. Our primary outcome was the rate of intraoperative difficulty on the modified Nassar scale (MNS). Statistical analysis was performed using SPSS version 25.0 (IBM Corp., Armonk, NY).

RESULTS

We included 70 patients who underwent LC for gallstones (CVS not achieved = 24 and CVS achieved = 46). The mean (SD) age was 42.2 (12.3) years, and 73.5% were females. The mean (SD) weight in our study cohort was 74.1 (10.9) kg, and there was no difference between the two groups in terms of the baseline demographic characteristics, disease characteristics, and comorbid conditions (p > 0.05). On univariate analyses, achieving CVS was associated with lower rates of higher-grade operative difficulty on the MNS and lower rates of length of stay of more than one day.

CONCLUSION

Achieving CVS is associated with easy LC based on significantly lower Nassar scores. These findings highlight the role of the MNS in the successful identification of the operative difficulty of LC and its correlation with achieving CVS.

Boosting SARS-CoV-2 Enrichment with Ultrasmall Immunomagnetic Beads Featuring Superior Magnetic Moment

The isolation and enrichment efficiency of SARS-CoV-2 virus in complex biological environments is often relatively low, presenting challenges in direct detection and an increased risk of false negatives, particularly during the early stages of infection. To address this issue, we have developed a novel approach using ultrasmall magnetosome-like nanoparticles (≤10 nm) synthesized via biomimetic mineralization of the Mms6 protein derived from magnetotactic bacteria. These nanoparticles are surface-functionalized with hydrophilic carboxylated polyethylene glycol (mPEG2000-COOH) to enhance water solubility and monodispersity. Subsequently, they are coupled with antibodies targeting the receptor-binding domain (RBD) of the virus. The resulting magnetosome-like immunomagnetic beads (Mal-IMBs) exhibit high magnetic responsiveness comparable to commercial magnetic beads, with a saturation magnetization of 90.6 emu/g. Moreover, their smaller particle size provides a significant advantage by offering a higher specific surface area, allowing for a greater number of RBD single-chain fragment variable (RBD-scFv) antibodies to be coupled, thereby enhancing immune capture ability and efficiency. To validate the practicality of Mal-IMBs, we evaluated their performance in recognizing the RBD antigens, achieving a maximum capture ability of 83 μg/mg per unit mass. Furthermore, we demonstrated the binding capability of Mal-IMBs to SARS-CoV-2 pseudovirus using fluorescence microscopy. The Mal-IMBs effectively enriched the pseudovirus at a low copy concentration of 70 copies/mL. Overall, the small Mal-IMB exhibited excellent magnetic responsiveness and binding efficiency. By employing a multisite virus binding mechanism, it significantly improves the enrichment and separation of SARS-CoV-2 in complex environments, facilitating rapid detection of COVID-19 and contributing to effective measures against its spread.

Numerical optimization and performance evaluation of ZnPC:PC70BM based dye-sensitized solar cell

The increase in global energy consumption and the related ecological problems have generated a constant demand for alternative energy sources superior to traditional ones. This is why unlimited photon-energy harnessing is important. A notable focus to address this concern is on advancing and producing cost-effective low-loss solar cells. For efficient light energy capture and conversion, we fabricated a ZnPC:PC70BM-based dye-sensitized solar cell (DSSC) and estimated its performance using a solar cell capacitance simulator (SCAPS-1D). We evaluated the output parameters of the ZnPC:PC70BM-based DSSC with different photoactive layer thicknesses, series and shunt resistances, and back-metal work function. Our analyses show that moderate thickness, minimum series resistance, high shunt resistance, and high metal-work function are favorable for better device performance due to low recombination losses, electrical losses, and better transport of charge carriers. In addition, in-depth research for clarifying the impact of factors, such as thickness variation, defect density, and doping density of charge transport layers, has been conducted. The best efficiency value found was 10.30% after tweaking the parameters. It also provides a realistic strategy for efficiently utilizing DSSC cells by altering features that are highly dependent on DSSC performance and output.

Design, Synthesis, and Biological Evaluation of Dexibuprofen Derivatives as Novel Anti-inflammatory, Antioxidant and Molecular Docking Studies

Prodrugs of dexibuprofen having ester moieties instead of free carboxylic acid which involves in gastrointestinal side effects have been synthesized. Dexibuprofen acid was condensed with different alcohols/phenols to afford the ester prodrugs. All of the synthesized prodrugs were characterized by their physical attributes, elemental analysis, FTIR, 1H NMR, and 13C NMR spectroscopy. The in vitro anti-inflammatory studies was done by chemiluminescence technique reflect prodrugs have been more potent, owing to the different chemical structures. Lipoxygenase enzyme inhibition assay was also assess and found compound DR7 with IC50 = 19.8 µM), DR9 (IC50 = 24.3 µM) and DR3 (IC50 = 42.7 µM) as compared with parent drug (IC50 = 156.6 µM). It was also evaluated for docking studies revealed that DR7 has found to be more potent anti-inflammatory against 5-LOX (3V99) as well as analgesic against COX-II (5KIR) enzyme. Anti-oxidant activities were also performed, DR3 (80.9%), DR4 (83.5%), DR7 (93.9%) and DR9 (87.4%) were found to be more anti-oxidant as compared to (2S)-2-[4-(2-methylpropyl)phenyl]propanoic acid (52.7%).

Rhodium-Catalyzed Regio- and Enantioselective Allylic Sulfonylation from Sulfonyl Hydrazides

A highly regio- and enantioselective allylic sulfonylation has been developed with rhodium and bisoxazolinephosphine (NPN*) ligands from racemic branched allylic carbonates and readily available sulfonyl hydrazides under neutral conditions. Branch-selective allylic sulfones with a >20:1 branch:linear ratio and >99% ee could be synthesized in ≤96% yield. Both Z and E linear allylic carbonates could also be converted into the same chiral branched allylic sulfones with high regio- and enantioselectivities.

Rh-Catalyzed Regio- and Enantioselective Allylic Phosphinylation

Transition-metal-catalyzed branched and enantioselective allylic substitution of monosubstituted precursors with carbon, nitrogen, oxygen, sulfur, and fluoride nucleophiles has been well-established. However, such a selective carbon-phosphorus bond formation has not been realized probably due to the catalyst deactivation by the strong coordinating nature of phosphinylating reagents. Herein, we report a Rh-catalyzed highly regio- and enantioselective synthesis of allylic phosphine oxides in the presence of a chiral bisoxazoline-phosphine ligand. The application of α-hydroxylalkylphosphine oxides to keep the low concentration of the secondary phosphine oxides is essential for the high yields. The addition of diphenyl phosphoric acid was found to not only activate allylic alcohols but also accelerate the carbon-phosphorus bond formation.

Cobalt-catalyzed regiodivergent hydrofunctionalization of allenes

A regiodivergent cobalt-catalyzed addition of carboxylic acid or 1,3-dicarbonyl compounds to allenes has been developed to prepare E-enol esters and allylation products.

Expression analysis of transcription factors in sugarcane during cold stress

Transcription factors (TF) are a wide class of genes in plants, and these can regulate the expression of other genes in response to various environmental stresses (biotic and abiotic). In the current study, transcription factor activity in sugarcane was examined during cold stress. Initially, RNA transcript reads of two sugarcane cultivars (ROC22 and GT08-1108) under cold stress were downloaded from SRA NCBI database. The reads were aligned into a reference genome and the differential expression analyses were performed with the R/Bioconductor edgeR package. Based on our analyses in the ROC22 cultivar, 963 TF genes were significantly upregulated under cold stress among a total of 5649 upregulated genes, while 293 TF genes were downregulated among a total of 3,289 downregulated genes. In the GT08-1108 cultivar, 974 TF genes were identified among 5,649 upregulated genes and 283 TF genes were found among 3,289 downregulated genes. Most transcription factors were annotated with GO categories related to protein binding, transcription factor binding, DNA-sequence-specific binding, transcription factor complex, transcription factor activity in RNA polymerase II, the activity of nucleic acid binding transcription factor, transcription corepressor activity, sequence-specific regulatory region, the activity of transcription factor of RNA polymerase II, transcription factor cofactor activity, transcription factor activity from plastid promoter, transcription factor activity from RNA polymerase I promoter, polymerase II and RNA polymerase III. The findings of above results will help to identify differentially expressed transcription factors during cold stress. It also provides a comprehensive analysis of the regulation of the transcription activity of many genes. Therefore, this study provides the molecular basis for improving cold tolerance in sugarcane and other economically important grasses.

Sensitivity analysis and optimal control of COVID-19 dynamics based on SEIQR model

It is of great curiosity to observe the effects of prevention methods and the magnitudes of the outbreak including epidemic prediction, at the onset of an epidemic. To deal with COVID-19 Pandemic, an SEIQR model has been designed. Analytical study of the model consists of the calculation of the basic reproduction number and the constant level of disease absent and disease present equilibrium. The model also explores number of cases and the predicted outcomes are in line with the cases registered. By parameters calibration, new cases in Pakistan are also predicted. The number of patients at the current level and the permanent level of COVID-19 cases are also calculated analytically and through simulations. The future situation has also been discussed, which could happen if precautionary restrictions are adopted.

Ammonium nitrate is a risk for environment: A case study of Beirut (Lebanon) chemical explosion and the effects on environment

An attempt has been made in correspondence to explain the consequences of chemical pollution after the explosion of ammonium nitrate (AN) in Beirut (capital of Lebanon). The effects of chemicals in the air, soil, and water have been discussed. In addition, the study emphasizes on the research to restore the environment and enhanced safety measurements.

Optical characterization of non-thermal plasma jet energy carriers for effective catalytic processing of industrial wastewaters

An argon plasma jet was sustained in open air and characterized for its chemical composition. The optically characterized plasma jet was used to treat industrial wastewater containing mixed textile dyes and heavy metals. Since plasma jet produces UV-radiations, the photocatalytic TiO₂ was used to enhance plasma treatment efficiency especially for degradation of dyes. Mixed anatase and rutile phases of TiO₂ (5.2-8.5 nm) were produced through surfactant assisted sol-gel approach. The emission spectrum confirmed the presence of excited argon, OH, excited nitrogen, excited oxygen, ozone and nitric oxide in the plasma jet. The spectral lines of excited Ar, NO, O₃, OH^-, N₂, [Formula: see text], O, [Formula: see text] and O⁺ species were observed at wavelength of 695-740 nm, 254.3 nm, 307.9 nm, 302-310 nm, 330-380 nm, 390-415 nm, 715.6 nm, 500-600 nm and 400-500 nm. These reactive species decompose the organic pollutants and separate the heavy metals from the water samples. The conductivity of plasma exposed water samples increased while pH and hardness decreased. The atomic absorption spectrophotometry analysis confirmed the presence of heavy metals in the samples, which were effectively removed through plasma treatment. Finally, the effect of plasma treatment on Staphylococcus aureus strains was more pronounced than Escherichia coli strains.

Knowledge, attitude, practice and perceived barriers among healthcare workers regarding COVID-19: a cross-sectional survey from Pakistan

A self-administered validated (Cronbach's alpha=0.077) questionnaire was used to assess knowledge, attitude and practice among healthcare workers (HCWs) in Pakistan regarding coronavirus disease 2019 (COVID-19). Findings showed that HCWs have good knowledge (93.2%, N=386), a positive attitude [mean 8.43 (standard deviation 1.78)] and good practice (88.7%, N=367) regarding COVID-19. HCWs perceived that limited infection control material (50.7%, N=210) and poor knowledge regarding transmission (40.6%, N=168) were the major barriers to infection control. Regression analysis indicated that pharmacists were more likely to demonstrate good practice than other HCWs (odds ratio 2.247, 95% confidence interval 1.11-4.55, P=0.025). This study found that HCWs in Pakistan have good knowledge, but there are gaps in specific aspects of knowledge and practice that warrant attention.

Knowledge, attitude, practice and perceived barriers among healthcare workers regarding COVID-19: a cross-sectional survey from Pakistan

A self-administered validated (Cronbach's alpha=0.077) questionnaire was used to assess knowledge, attitude and practice among healthcare workers (HCWs) in Pakistan regarding coronavirus disease 2019 (COVID-19). Findings showed that HCWs have good knowledge (93.2%, N=386), a positive attitude [mean 8.43 (standard deviation 1.78)] and good practice (88.7%, N=367) regarding COVID-19. HCWs perceived that limited infection control material (50.7%, N=210) and poor knowledge regarding transmission (40.6%, N=168) were the major barriers to infection control. Regression analysis indicated that pharmacists were more likely to demonstrate good practice than other HCWs (odds ratio 2.247, 95% confidence interval 1.11-4.55, P=0.025). This study found that HCWs in Pakistan have good knowledge, but there are gaps in specific aspects of knowledge and practice that warrant attention.

Pulsed radiofrequency modulation for lingual neuralgia

Pulsed radiofrequency modulation (PRM) is a minimally invasive procedure that has been used successfully to treat neuropathic pain. Its use to treat lingual neuralgia has not to our knowledge been described previously, and we report a case.

Advances in heart failure: natriuretic peptide testing

Natriuretic peptide testing in the form of B-type natriuretic peptide (BNP) or NT-proBNP measurement has revolutionized modern heart failure (HF) diagnostics for those patients with acute symptoms, and promises to have similarly profound effects not only for the earlier recognition of those with HF, but also for the therapy of patients across the entire spectrum of HF. Future efforts are necessary to better understand the complex biology of the natriuretic peptides, to further optimize use of the assays for their measurement, and to gain clarity regarding the appropriate venue for their measurement. The ultimate goal is to recognize more readily and treat the syndrome that is HF, in order to reduce the considerable morbidity and mortality among those so afflicted.

Sampling methods as abundance indices for adult Diaprepes abbreviatus (Coleoptera: Curculionidae) in citrus

Beat sampling and two type of traps, cup traps and Tedders traps, were evaluated as sampling methods to detect and estimate population densities of adult Diaprepes abbreviatus L. weevils newly colonizing young citrus trees. The study was conducted over a 65-wk period across a 0.25-ha area of 80 citrus trees [Citrus sinensis (L.) Osbeck] (1.2-1.5 m tall). Beat samples were taken weekly to determine the number of trees infested and number of new adult weevils per tree. Sixteen of the 80 trees studied were each monitored weekly using one of the following trapping methods: cup traps in trees, cup traps on a stake in the ground within the tree drip line, cup traps on a stake in the ground outside of the drip line, Tedders traps on the ground within the drip line, and Tedders traps on the ground outside of the drip line. Weevils collected each week from trees and traps were removed from the study site. Based on the coefficients associated with Taylor's power law, the optimum numbers of trees to sample for an SEM equal to 25% of the mean estimate decreased from 50 trees at a mean of 0.5 new weevils per tree to 30 trees at a mean of 0.8 new weevils per tree. A significant relationship was found between the weekly mean number of new weevils per tree and the proportion of trees infested, a binomial relationship that could be further explored in the search for a sampling program for adult D. abbreviatus. Regression analyses indicated that three of the trapping methods served at least as weak indices of the presence and abundance of new weevils: cup traps in trees, Tedders traps inside the dripline and Tedders traps outside the dripline. Cup traps in trees and Tedders traps inside the dripline captured the most weevils and most frequently detected weevils. Although relatively inefficient as abundance indices of populations of new weevils, these two trapping methods appeared to have some value with respect to signaling when weevils first appeared in trees during the spring.

Microbiological and biochemical characteristics of Canestrato Pugliese cheese made from raw milk, pasteurized milk or by heating the curd in hot whey

Canestrato Pugliese cheeses were produced from raw ewes' milk (R and R(II) cheeses), pasteurized ewes' milk (P cheese) and by heating the curd in hot whey according to a traditional protocol (T cheese). R(II) differed from R cheese mainly by having been produced from raw milk with a higher number of somatic cells, 950.000 vs. 750.000 ml(-1), respectively. Compared to P and T cheeses, R and R(II) cheeses had a higher concentration (one or two orders of magnitude) of cheese-related bacteria such as adventitious mesophilic lactobacilli, enterococci and staphylococci. At the end of ripening, all cheeses contained less than 1.0 log cfu g(-1) of total and fecal coliforms, and Escherichia coli and Staphylococcus aureus were not detected. As shown by phenotypic identification and RAPD-PCR, R cheese contained the largest number of mesophilic lactobacilli species and the greatest diversity of strains within the Lactobacillus plantarum species. Primary proteolysis did not differ appreciably among the cheeses. On the contrary, both urea-PAGE and the RP-HPLC analyses of the water-soluble N fractions showed the more complex profiles in cheeses produced by raw milks. R and R(II) cheeses had the highest values of water-soluble N/total N (ca. 30%) and the highest concentration of total free amino acids (ca. 40 mg g(-1) which approached or exceeded those reported for Italian cheeses with very high level of proteolysis during ripening. The main differences between R-R(II) and P-T cheeses were the concentrations of aspartic acid, proline, alanine, isoleucine, histidine and lysine. The water-soluble extracts of R and R(II) cheeses contained levels of amino-, imino- and di-peptidase activities, which were about twice those found in P and T cheeses. Cheeses differed slightly in the concentration of total free fatty acids that ranged between 1673 and 1651 mg kg(-1) in R and R(II) cheeses, and 1397 and 1334 mg kg(-1) in P and T cheeses. Butyric, caproic, capric, palmitic, oleic and linoleic acids were found at the highest concentrations.

Hepatic resection at a community hospital

Hepatic resection remains the "gold standard" in the primary management of primary and metastatic tumors to the liver. Advanced surgical techniques along with more modern and sophisticated equipment have led to an increasing number of hepatic resections being performed with a concomitant decrease in morbidity and mortality. We followed prospectively 18 consecutive hepatic resections performed over a period of approximately 2.5 years. The setting was a community teaching hospital with a low volume of referrals for hepatic resection. Sixteen (88%) had metastatic disease and two had primary liver disease. There were four trisegmentectomies, four lobectomies, four segmentectomies, and six large wedge re-sections. Average estimated blood loss was 608 ml. Seven patients required transfusions. Complications occurred in five patients (27%). In-hospital mortality was 0%. Our experience suggests that liver resections in a low-volume community hospital can be performed safely provided an experienced surgical team with familiarity of advanced surgical techniques and sophisticated equipment used in hepatic resection is readily available.

Diaphragmatic rupture: A complication of violent cough

The cough is a complex physiologic response designed to protect airways from unwanted secretions and foreign materials. Violent and paroxysmal coughs are associated with many complications. In this article, we will discuss a patient who sustained diaphragmatic rupture as a result of violent coughing. The possible mechanisms of this rare complication are explained.

Intradialytic serial vascular access flow measurements

Hemodialysis vascular access failure represents a major source of morbidity and mortality in chronic hemodialysis (CHD) patients. Serial vascular access blood flow (VABF) measurements are being used as a screening method at an increasing rate. There are limited data on the changes in VABF throughout the hemodialysis session, which may potentially affect the validity of VABF measurement. This study is performed to evaluate the trend in VABF during a given hemodialysis session by serial VABF measurements, along with potential factors that may affect VABF. Thirty-two CHD patients had serial VABF measurements performed during a hemodialysis session. Each patient had three serial VABF measurements during a hemodiaysis treatment (within 30, 90, and 150 minutes from the start of hemodialysis). Mean arterial blood pressure (MAP), ultrafiltration rate, and patient symptoms were recorded simultaneously. The mean VABF was 1,344 +/- 486 mL/min within 30 minutes of hemodialysis and decreased to 1,308 +/- 532 and 1,250 +/- 552 mL/min after 90 and 150 minutes, respectively. This trend was statistically significant (P = 0.03). There was a strong correlation between VABF measurements and MAP, which was more pronounced after 90 minutes of initiation of hemodialysis (r = 0.68; P < 0.001). Using multivariate analysis, it can be predicted that after 90 minutes of hemodialysis, each 10% decrease in MAP would result in an expected decrease of 8% in VABF. There was no effect of type of vascular access, baseline VABF, or amount of ultrafiltration on VABF changes. In conclusion, VABF measurements can be performed up to 2 to 2(1/2) hours from the start of hemodialysis in the majority of patients. The major determinant of VABF changes is MAP. In a subset of patients with a decrease MAP greater than 15%, it is advisable to perform VABF measurement either at the first 90 minutes of hemodialysis or postpone it to another treatment session, when MAP is more stable.

Reversible dementia due to dural arteriovenous fistula: a simple surgical option

Dural AVMs can produce a wide variety of symptoms related to raised intracranial pressure, venous congestion, and cerebral ischaemia. We present a unique case of reversible dementia, due to venous hypertension. The cerebral ischaemia was caused by extensive bilateral arteriovenous malformations of the external carotid system, which drained into the superior sagittal and transverse sinuses and resulted in venous hypertension. Although partial occlusion by endovascular embolization and ligation procedures had some effect, only 'scalping and silastic implantation' gave satisfactory amelioration of symptoms.

Traumatic extradural hematoma of delayed onset is not a rarity

During a 4.5-year period, 73 patients with traumatic extradural hematoma (EDH) were admitted to the neurosurgical unit of the same hospital and managed with surgical evacuation. Of these consecutive admissions, 22 patients with delayed EDH are reported. The incidence of this condition (30%; 22 of 73) contrasts with reports in the literature of 0 to 10%. This may be related to the availability of computed tomography and its liberal and early use in all head injuries. The overall mortality of traumatic EDH (5%; 4 of 73) was related to cases of delayed onset EDH. In addition to a high index of suspicion, early diagnosis of delayed EDH can be facilitated by liberal use of intracranial pressure monitoring and serial computed tomography.

Zinc, copper and lead levels in blood, spinal cord and different parts of the brain in rabbit: effect of zinc-intoxication

The effect of zinc (8 mg/kg body weight, intraperitoneally) administration daily for 7 consecutive days was studied on the levels of Zn++, Cu++ and Pb++ in the blood, spinal cord and different regions of the brain in rabbits. It was found that with increase in Zn++ concentration there was a decrease in copper levels and an increase in lead levels in almost all parts of the brain. In the blood, both copper and lead levels were significantly decreased. No definite mechanism for the changes can be postulated. The study suggests that changes of Zn++ concentration beyond physiological limits can affect the concentration of other essential and non-essential metal ions.