Physical characterization, biocompatibility, and antimicrobial activity of polyvinyl alcohol/sodium alginate blend doped with TiO2 nanoparticles for wound dressing applications

The ability of wound dressing materials to tackle skin pathogens colonization that is associated with open wound infections is limited. Recently, green-synthesized metal oxide nanoparticles has received a lot of attention to overcome this limitation. However, titanium dioxide nanoparticles (TiO2-NPs) exhibit exceptional antibacterial properties. In this work, several concentrations (0, 1, 3, and 5 wt.%) of TiO2 NPs prepared using Aloe vera leaf extract were added to a blend of polyvinyl alcohol and sodium alginate (PVA:SA). This nanocomposite was designed to enhance the healing process of wounds. The interaction between the PVA:SA composite and the TiO2 NPs was confirmed by FTIR. The thermal behavior of the nanocomposite films was investigated using DSC and TGA. The experimental results indicate that the glass transition temperatures of the nanocomposites increased by increasing the added amount of TiO2 NPs to be 53.7 °C (1 wt.%), 55.8 °C (3 wt.%), and 60.6 °C (5 wt.%), which were consistently lower than the glass transition temperature of the matrix material (69.6 °C). The Dynamic Mechanical Analysis was examined. The nanocomposite doped with 5 wt.% of TiO2 NPs detected a high storage modulus (21.6 × 108). Based on swelling and degradation studies, the prepared PVA:SA:TiO2 nanocomposite films have an excellent swelling rate, and the inclusion of TiO2 NPs increases the stability of the polymeric matrix. The PVA:SA:TiO2 nanocomposite films exhibited a superior antibacterial efficacy against Gram-positive bacteria such as Bacillus cereus and Staphylococcus aureus, compared to their effectiveness against Gram-negative bacteria like Escherichia coli. Moreover, the nanocomposite films were biocompatible with Human Skin Fibroblast. Therefore, the developed PVA:SA:TiO2 nanocomposite films suit wound dressing applications.

Utility of the Addenbrooke’s Cognitive Examination III online calculator to differentiate the primary progressive aphasia variants

The Addenbrooke’s Cognitive Examination III is a brief cognitive screening tool that is widely used for the detection and monitoring of dementia. Recent findings suggest that the three variants of primary progressive aphasia can be distinguished based on their distinct profiles on the five subdomain scores of this test. Here, we investigated the utility of the Addenbrooke’s Cognitive Examination III to differentiate the primary progressive aphasia variants based on their item-by-item performance profiles on this test. From these results, we created an interactive primary progressive aphasia Addenbrooke’s Cognitive Examination III calculator which predicts the variant based on a patient’s unique item-by-item profile. Twenty-eight logopenic variant, 25 non-fluent variant and 37 semantic variant primary progressive aphasia patients and 104 healthy controls completed the Addenbrooke’s Cognitive Examination III at first clinical presentation. Multinomial regression analyses were conducted to establish performance profiles among groups, and R Shiny from RStudio was used to create the interactive Addenbrooke’s Cognitive Examination III diagnostic calculator. To verify its accuracy, probability values of the regression model were derived based on a 5-fold cross-validation of cases. The calculator’s accuracy was then verified in an independent sample of 17 logopenic, 19 non-fluent and 13 semantic variant primary progressive aphasia patients and 68 Alzheimer’s disease patients who had completed the Addenbrooke’s Cognitive Examination III (or an older version of this test: Revised) and had in vivo amyloid-PET imaging and/or brain autopsy pathological confirmation. Cross-validation of cases in the calculator model revealed different rates of sensitivity in classifying variants: semantic = 100%, non-fluent = 80.6% and logopenic = 79.9%; healthy controls were distinguished from primary progressive aphasia patients with 100% sensitivity. Verification of in vivo amyloid and/or autopsy-confirmed patients showed that the calculator correctly classified 10/13 (77%) semantic variant, 3/19 (16%) non-fluent variant and 4/17 (24%) logopenic variant patients. Importantly, for patients who were not classified, diagnostic probability values mostly pointed toward the correct clinical diagnosis. Furthermore, misclassified diagnoses of the primary progressive aphasia cohort were rare (1/49; 2%). Although 22 of the 68 Alzheimer’s disease patients (32%) were misclassified with primary progressive aphasia, 19/22 were misclassified with the logopenic variant (i.e. falling within the same neuropathological entity). The Addenbrooke’s Cognitive Examination III primary progressive aphasia diagnostic calculator demonstrates sound accuracy in differentiating the variants based on an item-by-item Addenbrooke’s Cognitive Examination III profile. This calculator represents a new frontier in using data-driven approaches to differentiate the primary progressive aphasia variants.

Therapeutic vulnerability to PARP1,2 inhibition in RB1-mutant osteosarcoma

Loss-of-function mutations in the RB1 tumour suppressor are key drivers in cancer, including osteosarcoma. RB1 loss-of-function compromises genome-maintenance and hence could yield vulnerability to therapeutics targeting such processes. Here we demonstrate selective hypersensitivity to clinically-approved inhibitors of Poly-ADP-Polymerase1,2 inhibitors (PARPi) in RB1-defective cancer cells, including an extended panel of osteosarcoma-derived lines. PARPi treatment results in extensive cell death in RB1-defective backgrounds and prolongs survival of mice carrying human RB1-defective osteosarcoma grafts. PARPi sensitivity is not associated with canonical homologous recombination defect (HRd) signatures that predict PARPi sensitivity in cancers with BRCA1,2 loss, but is accompanied by rapid activation of DNA replication checkpoint signalling, and active DNA replication is a prerequisite for sensitivity. Importantly, sensitivity in backgrounds with natural or engineered RB1 loss surpasses that seen in BRCA-mutated backgrounds where PARPi have established clinical benefit. Our work provides evidence that PARPi sensitivity extends beyond cancers identifiable by HRd and advocates PARP1,2 inhibition as a personalised strategy for RB1-mutated osteosarcoma and other cancers.

Effect of genistein and oestradiol on the adrenal cortex of the ovariectomised adult female albino rats

BACKGROUND

Genistein, a naturally occurring soy isoflavone, attracts interest as an effective and safe alternative to hormone replacement therapy for menopausal problems. The aim of the current study was to compare between the effect of genistein and oestradiol on the adrenal cortex of the ovariectomised adult female albino rats.

MATERIALS AND METHODS

Twenty rats were used in the current study and divided into four groups, 5 rats in each group; group 1 (control non-ovariectomised), group 2 (ovariectomised), group 3 (ovariectomised + genistein) and group 4 (ovariectomised + oestradiol). The rats were sacrificed after 4 weeks. Both adrenal glands were removed for light microscope using haematoxylin and eosin stain, ultrastructural study and immunohistochemical examination using proliferating cell nuclear antigen, caspase-3, and oestrogen receptor-b.

RESULTS

Ovariectomised rats showed signs of degeneration in all zones of adrenal cortex. On the other hand, treatment with genistein showed restoration of the adrenal cortex with less proliferative effect than oestradiol.

CONCLUSIONS

So, genistein can be used as effective therapy to decrease the symptoms of menopause without fear of cancer development.

Predictors of survival and progression in behavioural variant frontotemporal dementia

BACKGROUND AND PURPOSE

Predicting the course of behavioural variant frontotemporal dementia (bvFTD) remains a major clinical challenge. This study aimed to identify factors that predict survival and clinical progression in bvFTD.

METHODS

Consecutive patients with clinically probable bvFTD were prospectively followed up over an 8-year period. Baseline neuropsychological variables, presence of a known pathogenic frontotemporal dementia gene mutation and a systematic visual magnetic resonance imaging assessment at baseline were examined as candidate predictors using multivariate modelling.

RESULTS

After screening 121 cases, the study cohort consisted of 75 patients with probable bvFTD, with a mean age of 60.8 ± 8.5 years, followed up for a mean duration of 7.2 ± 3.5 years from symptom onset. Median survival time from disease onset was 10.8 years and median survival, prior to transition to nursing home, was 8.9 years. A total of 25 of the 75 patients died during the study follow-up period. Survival without dependence was predicted by shorter disease duration at presentation (hazard ratio, 0.49, P = 0.001), greater atrophy in the anterior cingulate cortex (hazard ratio, 1.75, P = 0.047), older age (hazard ratio, 1.07, P = 0.026) and a higher burden of behavioural symptoms (hazard ratio, 1.04, P = 0.015). In terms of disease progression, presence of a known pathogenic frontotemporal dementia mutation (β = 0.46, P < 0.001) was the strongest predictor of progression. Deficits in letter fluency (β = -0.43, P = 0.017) and greater atrophy in the motor cortex (β = 0.51, P = 0.03) were also associated with faster progression.

CONCLUSIONS

This study provides novel clinical predictors of survival and progression in bvFTD. Our findings are likely to have an impact on prognostication and care planning in this difficult disease.

Biomarkers in dementia: clinical utility and new directions

Imaging, cerebrospinal fluid (CSF) and blood-based biomarkers have the potential to improve the accuracy by which specific causes of dementia can be diagnosed in vivo, provide insights into the underlying pathophysiology, and may be used as inclusion criteria and outcome measures for clinical trials. While a number of imaging and CSF biomarkers are currently used for each of these purposes, this is an evolving field, with numerous potential biomarkers in varying stages of research and development. We review the currently available biomarkers for the three most common forms of neurodegenerative dementia, and give an overview of research techniques that may in due course make their way into the clinic.

The Pseudotumor Cerebri Syndrome: A Unifying Pathophysiological Concept for Patients with Isolated Intracranial Hypertension with Neither Mass Lesion Nor Ventriculomegaly

In 1991 we proposed that while the syndrome of isolated intracranial hypertension might have many definite and probable causes, it has nonetheless a single unifying pathophysiological mechanism: namely, impairment of cerebrospinal fluid (CSF) reabsorption. For that reason, we also proposed then that it is best described by a single, unifying, inclusive term, namely, pseudotumor cerebri syndrome. Although it appears that there is, as far as nomenclature is concerned, now international agreement, there is as yet no agreement on pathophysiology and classification. Herein we outline our views on these matters and give our reasons.

Transverse sinus stenting for pseudotumor cerebri: a cost comparison with CSF shunting

BACKGROUND AND PURPOSE

Transverse sinus venous stent placement has been shown to lower intracranial pressure in patients with venogenic pseudotumor cerebri and to reverse, or at least stabilize, its symptoms and signs. There have been no studies comparing the cost of venous stenting with the time-honored treatment for pseudotumor cerebri-CSF shunting. The purpose of this study was to compare the cost of trasverse sinus stenting versus CSF shunting for the treatment of pseudotumor cerebri.

MATERIALS AND METHODS

This work was a retrospective cost analysis of individual resource use in 86 adults who were stented for pseudotumor cerebri during a 12-year period compared with resource use in 110 children who were shunted for hydrocephalus during a 3-year period.

RESULTS

There was no significant difference between the cost of inserting an initial venous stent ($13,863 ± 4890) versus inserting an initial CSF shunt ($15,797 ± 5442) (P = .6337) or between inserting an additional venous stent ($9421 ± 69) versus revising a CSF shunt ($10,470 ± 1245) (P = .4996). There were far fewer additional venous stent insertions per patient than there were subsequent CSF shunt revisions; 87% of stents placed required just 1 stent procedure, whereas only 45% of shunts required 1 shunt procedure. The main cause of the cost difference was the need for repeated revisions of the shunts, especially when they became infected-24 instances of a total 143 shunt procedures (16.8%) at an average cost of $84,729, approximately 5 times the cost of an initial shunt insertion.

CONCLUSIONS

Venous stenting costs significantly less per 100 procedures than does CSF shunting, due largely to the high cost of treating shunt infections and the need for repeated shunt revisions.

Malignant meningitis presenting as pseudotumor cerebri

Malignant leptomeningitis can present as the clinical syndrome of pseudotumor cerebri due to infiltration of arachnoid villi in the superior sagittal sinus. We show that malignant pachymeningitis can also present with pseudotumor cerebri, likely due to cerebral venous hypertension from transverse sinus compression. We present 3 cases of pseudotumor cerebri due to pachymeningeal or leptomeningeal metastases and discuss the mechanism of intracranial hypertension in such cases, its diagnosis and treatment.

Transverse sinus stenting for idiopathic intracranial hypertension: a review of 52 patients and of model predictions

BACKGROUND AND PURPOSE

Transverse sinus stenosis is common in patients with IIH. While the role of transverse sinus stenosis in IIH pathogenesis remains controversial, modeling studies suggest that stent placement within a transverse sinus stenosis with a significant pressure gradient should decrease cerebral venous pressure, improve CSF resorption in the venous system, and thereby reduce intracranial (CSF) pressure, improving the symptoms of IIH and reducing papilledema. We aimed to determine if IIH could be reliably treated by stent placement in transverse sinus stenosis.

MATERIALS AND METHODS

We reviewed the clinical, venographic, and intracranial pressure data before and after stent placement in transverse sinus stenosis in 52 of our own patients with IIH unresponsive to maximum acceptable medical treatment, treated since 2001 and followed between 2 months and 9 years.

RESULTS

Before stent placement, the mean superior sagittal sinus pressure was 34 mm Hg (462 mm H(2)0) with a mean transverse sinus stenosis gradient of 20 mm Hg. The mean lumbar CSF pressure before stent placement was 322 mm H(2)O. In all 52 patients, stent placement immediately eliminated the TSS pressure gradient, rapidly improved IIH symptoms, and abolished papilledema. In 6 patients, symptom relapse (headache) was associated with increased venous pressure and recurrent stenosis adjacent to the previous stent. In these cases, placement of another stent again removed the transverse sinus stenosis pressure gradient and improved symptoms. Of the 52 patients, 49 have been cured of all IIH symptoms.

CONCLUSIONS

These findings indicate a role for transverse sinus stent placement in the management of selected patients with IIH.

Coordination modes of novel rhodanine azodye complexes

The reaction products of metal(II) salts with 5-sulphamethoxazoleazo-3-phenyl-2-thioxo-4-thiazolidinone (H2L) have been characterized by elemental analyses, magnetic susceptibility, electronic, infrared and electron paramagnetic resonance spectral measurements. The spectral data suggest a square pyramidal structure for Cu(II) and Co(II) complexes and an octahedral for Ni(II) complexes. Various EPR parameters have been calculated. From the electron paramagnetic resonance and spectral data, the orbital reduction factors were calculated. In all case kperpendicular > kparallel which indicates a 2B1g ground state. These five coordinated complex of Cu(II) react further with pyridine forming six coordinate base adduct. The different modes of chelation of the ligand and stereochemistry around the metal ion are discussed.

Spectral studies on metal-ligand bonding of novel rhodanine azodye sulphadrugs

A series of novel complexes with 5-sulphadiazineazo-3-phenyl-2-thioxo-4-thiazolidinone (H2L1) and 5-sulphamethazineazo-3-phenyl-2-thioxo-4-thiazolidinone (H2L2) and various anions were prepared. Their structures and properties were characterized by elemental analyses, IR, UV-vis, EPR spectroscopy and magnetic measurements. The visible and EPR spectral studies indicated that the Cu(II) complexes have distorted octahedral. From the electron paramagnetic resonance and spectral data, the orbital reduction factors k(parallel) and k(perpendicular) were calculated. In all cases k(perpendicular) > k(parallel) indicates a 2B1g ground state. The crystal field parameters for Co(II) and Ni(II) complexes were calculated. The electronic absorption and a g(parallel)/A(parallel) values are indicative for the beginning of tetragonal distortion. The complexes, however, have lower symmetries and the amount of distortion in terms of DT/Dp, applying NSH 'Hamiltonian Theory' has been evaluated which indicate that the complexes are moderately distorted.