Effects of COVID-19 Pandemic Response on Service Provision for Sexually Transmitted Infections,HIV, and Viral Hepatitis,England

Since the coronavirus disease pandemic response began in March 2020, tests, vaccinations, diagnoses, and treatment initiations for sexual health, HIV, and viral hepatitis in England have declined. The shift towards online and outreach services happened rapidly during 2020 and highlights the need to evaluate the effects of these strategies on health inequalities.     

S-Nitrosoglutathione formation at gastric pH is augmented by ascorbic acid and by the antioxidant vitamin complex,Resiston

Context: Exogenous nitrogen oxides must be made bioavailable to sustain normal physiology because nitric oxide synthase (NOS) deficient mice are viable. In the stomach, S-nitrosoglutathione (GSNO) is formed from ingested nitrite and high levels of airway glutathione (GSH) that are cleared and swallowed. However, gastric GSNO may be broken down by nutrients like ascorbic acid (AA) before it is absorbed.

Objective: To study the effect of AA on GSNO formation and stability.

Materials and methods: GSH and nitrite were reacted with or without 5?mM AA or Resiston (5?mM AA with retinoic acid and α-tocopherol). GSNO was measured by reduction/chemiluminescence and HPLC. AA and reduced thiols were measured colorimetrically. O-Nitrosoascorbate and AA were measured by gas chromatography–mass spectrometry (GC–MS).

Results: GSNO was formed in saline and gastric samples (pH ～4.5) from physiological levels of GSH and nitrite. Neither AA nor Resiston decreased [GSNO] at pH >3; rather, they increased [GSNO] (0.12?±?0.19?μM without AA; 0.42?±?0.35?μM with AA; and 0.43?±?0.23?μM with Resiston; n?=?4 each; p?≤?0.05). However, AA compounds decreased [GSNO] at lower pH and with incubation >1?h. Mechanistically, AA, but not dehydroascorbate, increased GSNO formation; and the O-nitrosoascorbate intermediate was formed.

Conclusions: AA, with or without other antioxidants, did not deplete GSNO formed from physiological levels of GSH and nitrite at pH >3. In fact, it favoured GSNO formation, likely through O-nitrosoascorbate. Gastric GSNO could be a NOS-independent source of bioavailable nitrogen oxides.     

Phage probes for malignant glial cells

Early diagnosis and effective treatment of malignant gliomas, which are heterogeneous brain tumors with variable expression of cell surface markers, are inhibited by the lack of means to characterize and target tumor-selective molecules. To create molecular profiles for RG2 rat glioma cells, we used phage display technology, an approach capable of producing valuable ligands to unknown cell surface targets. The ligands were selected from libraries of peptides displayed as fusion molecules on phage particles. Modifications of the selection conditions resulted in identification of three distinctive families of peptide ligands for malignant glioma cells. The first family with V (D)/(G) L P (E)/(T) H(3) binding motif appeared to target a marker that is common for glioma cells, normal brain cells, and cells of non-brain origin. The second group of peptide-presented phage displayed D (T)/S/(L) T K consensus sequence and contained peptides with pronounced glioma-selective properties. Phage clones expressing peptides with E (L)/V/(S) R G D S motif were found in cell lysates and represented the third family of glioma-specific ligands. All peptides within this family contain the RGD amino acid sequence, which is known to bind to a number of integrins. Phage clones that belong to this family were internalized by RG2 glioma cells about 63-fold more efficiently than by astrocytes. The approach described could be applicable for accurate detection of glioma expression patterns in individual tumors. Such patterns could be beneficial in the design of effective combinations of drugs for anti-glioma treatments.     

Portal Vein Embolization in the Setting of Staged Hepatectomy with Preservation of Segment IV ± I Only for Bilobar Colorectal Liver Metastases: Safety,Efficacy, and Clinical Outcomes

Purpose

To assess frequency of adverse events, efficacy, and clinical outcomes of percutaneous portal vein embolization (PVE) in patients with bilobar colorectal liver metastases undergoing staged hepatectomy with preservation of segment IV ± I only.

Average spectral power changes at the hippocampal electroencephalogram in schizophrenia model induced by ketamine

The use of ketamine (Ket) as a pharmacological model of schizophrenia is an important tool for understanding the main mechanisms of glutamatergic regulated neural oscillations. Thus, the aim of the current study was to evaluate Ket‐induced changes in the average spectral power using the hippocampal quantitative electroencephalography (QEEG). To this end, male Wistar rats were submitted to a stereotactic surgery for the implantation of an electrode in the right hippocampus. After three days, the animals were divided into four groups that were treated for 10 consecutive days with Ket (10, 50, or 100 mg/kg). Brainwaves were captured on the 1st or 10th day, respectively, to acute or repeated treatments. The administration of Ket (10, 50, or 100 mg/kg), compared with controls, induced changes in the hippocampal average spectral power of delta, theta, alpha, gamma low or high waves, after acute or repeated treatments. Therefore, based on the alterations in the average spectral power of hippocampal waves induced by Ket, our findings might provide a basis for the use of hippocampal QEEG in animal models of schizophrenia.