Unlocking the potential of PROTACs: A comprehensive review of protein degradation strategies in disease therapy.

The technology known asPROTACs (PROteolysisTArgeting Chimeras) is a method of protein degradation. Utilising bifunctional small molecules, the ubiquitin-proteosome system (UPS) is used to induce the ubiquitination and degradation of target proteins. In addition to being novel chemical knockdown agents for biological studies that are catalytic, reversible, and rapid, PROTACs used in the treatment for disorders like cancer, immunological disorders, viral diseases, and neurological disorders. The protein degradation field has advanced quickly over the last two years, with a significant rise in research articles on the subject as well as a quick rise in smallmolecule degraders that are currently in or will soon enter the clinical stage. Other new degrading technologies, in addition to PROTAC and molecular glue technology, are also emerging rapidly. In this review article, we mainly focuses on various PROTAC molecules designed with special emphasis on targeted cellular pathways for different diseases i.e., cancer, Viral diseases Immune disorders, Neurodegenerative diseases, etc. We discussed about new technologies based on PROTACs such as Antibody PROTAC, Aptamers, Dual target, Folate caged, TF PROTAC, etc. Also, we listed out the PROTACs which are in clinical trials.

Effective Drug Candidates against Global Pandemic of Novel Corona Virus (nCoV-2019): A Probability Check through Computational Approach for Public Health Emergency.

The infection of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) started form Wuhan, Chinais a devastating and the incidence rate has increased worldwide. Due to the lack of effective treatment against SARS-CoV-2, various strategies are being tested in China and throughout the world, including drug repurposing. To identify the potent clinical antiretroviral drug candidate against pandemic nCov-19 through computational tools. In this study, we used molecular modelling tool (molecular modelling and molecular dynamics) to identify commercially available drugs that could act on protease proteins of SARS-CoV-2. The result showed that Saquinavir, an antiretroviral medication can be used as a first line agent to treat SARS-CoV-2 infection. Saquinavir showed promising binding to the protease active site compared to other possible antiviral agents such as Nelfinavir and Lopinavir. Structural flexibility is one of the important physical properties that affect protein conformation and function and taking this account we performed molecular dynamics studies. Molecular dynamics studies and free energy calculations suggest that Saquinavir binds better to the COVID-19 protease compared to other known antiretrovirals. Our studies clearly propose repurposing of known protease inhibitors for the treatment of COVID-19 infection. Previously ritonavir and lopinavir were proved an important analogues for SARS and MERS in supressing these viruses. In this study it was found that saquinavir has exhibited good G-score and E-model score compared to other analogues. So saquinavir would be prescribe to cure for nCov-2019 either single drug or maybe in combination with ritonavir.

Pharmacophore model and atom-based 3D quantitative structure activity relationship (QSAR) of human immunodeficiency virus-1 (HIV-1) capsid assembly inhibitors.

A potential anti-Human Immunodeficiency Virus (HIV) agent with novel mode of action is urgently needed to fight against drug resistance HIV. The HIV capsid protein is important for both late and early stages of the viral replication cycle and emerged as a promising target for the developing of small molecule inhibitors of HIV. We design a Pharmacophore and 3D Quantitative structure activity relationship (QSAR) model for HIV Capsid Protein inhibitors, which helps to identify overall aspects of molecular structure that govern activity and for the prediction of novel HIV Capsid inhibitors. The hypothesis was developed with a survival score of 3.6.The features, that is, two aromatic rings, one hydrophobic site and two acceptor regions were present in all the active compounds with good fitness score. Pharmacophore model was then validated by a partial least square and regression-based PHASE 3D QSAR cross-validation. The leave-n-out cross validation for test set (Q2) of the hypothesis is 0.636, the standard deviation (SD) value is 0.338, and the variance ratio (F-test) value is 74.5. Hypothesis also showed a leave-n-out cross validation for training set (R2, 0.928). Interestingly, the predicted activity of true test set compounds was found in the close vicinity of their experimental activity suggesting the methodology used and models generated can be applied to identify potential new chemical entities with better HIV-1 capsid assembly inhibition.Communicated by Ramaswamy H. Sarma.

Understanding and implementing alternative solutions to address the COVID-19 pandemic in the sense of public health emergencies.

The Coronavirus disease (COVID-19) caused by the novel SARS-CoV-2 coronavirus has spread from China and quickly transmitted to most other countries around the world. The World Health Organization announced COVID-19 as a pandemic that is spreading steadily and soon in most states. Coronavirus genomic characterization showed that it most closely resembled another bat-origin beta-coronavirus. Coronavirus has the largest genome of viruses that have RNA. Spike (S) glycoprotein is present in the virus and is responsible for virus entry into the host cell. COVID-19 can spread through the droplet, direct contact, and aerosol transmission in humans. It can remain in the environment and exists on plastic and steel for the longest time, making it a dangerous and contagious disease that can kill other individuals. The virus has an incubation time of 2 to 14 days. Confirmed cases of COVID-19 have evolved exponentially in the world. Possible preventive steps for disease control include more mask use, hand sanitization, and social distancing. There is no antiviral therapy and only symptomatic care. Many inhibitors of HIV protease and other antimalarial drugs have tested. There is currently no vaccine available for COVID-19 prevention, though others are available in clinical trials. Scientists often use spike proteins for vaccine production. Research is needed to develop a new innovative vaccine and targeted medicine, which will meet people's demands.

Amalgam tattoo mimicking mucosal melanoma: a diagnostic dilemma revisited.

Mucosal melanoma of the oral cavity is a rare but highly aggressive neoplasm. However, the clinicians need to be aware of the other and more frequent etiologies of intraoral pigmentation, such as amalgam tattoos. As amalgam has been extensively used for dental restorations and can cause pigmentations in the oral mucosa, this is a differential diagnosis not to be forgotten. We describe the characteristics of these two phenomena and present a case vignette illustrating the differential diagnostic issues. Other causes of intraoral pigmentation are summarized.

Mannan-binding lectin and healing of a radiation-induced chronic ulcer--a case report on mannan-binding lectin replacement therapy.

Mannan-binding lectin is an important component of innate immunity, and insufficiency is associated with several clinical disorders. Recently, experimental replacement therapy with plasma-derived mannan-binding lectin has become an option. The current article presents the case of a patient with an insufficient level of mannan-binding lectin and a chronic radiation-induced ulcer following the treatment of breast cancer. After 15 months of initially conservative treatment and thereafter plastic surgery, the healing was still impaired with necrosis in the periphery of the ulcer. Immunological work-up of the patient revealed pronounced insufficiency of mannan-binding lectin. Following a 6-week experimental intravenous treatment with mannan-binding lectin purified from human plasma, that is, 0.2-0.3 mg mannan-binding lectin per kg body weight twice a week, the defect was completely healed. We suggest that deficiency of mannan-binding lectin can explain cases of otherwise unexplained impaired healing, and that replacement therapy is considered in such cases.

A validated RP-HPLC method for quantitative determination of related impurities of ursodeoxycholic acid (API) by refractive index detection.

An isocratic RP-HPLC method was developed and validated for quantitative determination of ursodeoxycholic acid (UDCA) and its related impurities. Considering the lower molecular absorptivity of UDCA, refractive index detector was used to detect the impurities on a Phenomenex Luna C(18), 150 mm × 4.6 mm, 5 µm column. The mobile phase was 0.1% acetic acid/methanol (30:70, v/v) and flow rate was 0.8 ml/min. The detector and column temperature was maintained at 40°C. The method is linear over a range of 0.25-3.5 µg/ml for all impurities and coefficient of correlation (r(2)) was ≥0.9945. The accuracy of method demonstrated at three levels in the range of 50-150% of the specification limit and recoveries were found to be in the range of 97.11-100.75%. The precision for all related impurities was below 3.5% R.S.D. The method was applied to commercial bulk drug sample for assay purpose.

Ionotropic glutamate receptors and glutamate transporters are involved in necrotic neuronal cell death induced by oxygen-glucose deprivation of hippocampal slice cultures.

Organotypic hippocampal slice cultures represent a feasible model for studies of cerebral ischemia and the role of ionotropic glutamate receptors in oxygen-glucose deprivation-induced neurodegeneration. New results and a review of existing data are presented in the first part of this paper. The role of glutamate transporters, with special reference to recent results on inhibition of glutamate transporters under normal and energy-failure (ischemia-like) conditions is reviewed in the last part of the paper. The experimental work is based on hippocampal slice cultures derived from 7 day old rats and grown for about 3 weeks. In such cultures we investigated the subfield neuronal susceptibility to oxygen-glucose deprivation, the type of induced cell death and the involvement of ionotropic glutamate receptors. Hippocampal slice cultures were also used in our studies on glutamate transporters reviewed in the last part of this paper. Neurodegeneration was monitored and/or shown by cellular uptake of propidium iodide, loss of immunocytochemical staining for microtubule-associated protein 2 and staining with Fluoro-Jade B. To distinguish between necrotic vs. apoptotic neuronal cell death we used immunocytochemical staining for active caspase-3 (apoptosis indicator) and Hoechst 33342 staining of nuclear chromatin. Our experimental studies on oxygen-glucose deprivation confirmed that CA1 pyramidal cells were the most susceptible to this ischemia-like condition. Judged by propidium iodide uptake, a selective CA1 lesion, with only minor affection on CA3, occurred in cultures exposed to oxygen-glucose deprivation for 30 min. Nuclear chromatin staining by Hoechst 33342 and staining for active caspase-3 showed that oxygen-glucose deprivation induced necrotic cell death only. Addition of 10 microM of the N-methyl-D-aspartate glutamate receptor antagonist MK-801, and 20 microM of the non-N-methyl-D-aspartate glutamate receptor antagonist 2,3-dihyroxy-6-nitro-7-sulfamoyl-benzo(F)quinoxaline to the culture medium confirmed that both N-methyl-D-aspartate and non-N-methyl-D-aspartate ionotropic glutamate receptors were involved in the oxygen-glucose deprivation-induced cell death. Glutamate is normally quickly removed, from the extracellular space by sodium-dependent glutamate transporters. Effects of blocking the transporters by addition of the DL-threo-beta-benzyloxyaspartate are reviewed in the last part of the paper. Under normal conditions addition of DL-threo-beta-benzyloxyaspartate in concentrations of 25 microM or more to otherwise untreated hippocampal slice cultures induced neuronal cell death, which was prevented by addition of 2,3-dihyroxy-6-nitro-7-sulfamoyl-benzo(F)quinoxaline and MK-801. In energy failure situations, like cerebral ischemia and oxygen-glucose deprivation, the transporters are believed to reverse and release glutamate to the extracellular space. Blockade of the transporters by a subtoxic (10 microM) dose of DL-threo-beta-benzyloxyaspartate during oxygen-glucose deprivation (but not during the next 48 h after oxygen-glucose deprivation) significantly reduced the oxygen-glucose deprivation-induced propidium iodide uptake, suggesting a neuroprotective inhibition of reverse transporter activity by DL-threo-beta-benzyloxyaspartate during oxygen-glucose deprivation under these conditions. Adding to this, other results from our laboratory have demonstrated that pre-treatment of the slice cultures with glial cell-line derived neurotrophic factor upregulates glutamate transporters. As a logical, but in some glial cell-line derived neurotrophic factor therapy-related conditions clearly unwanted consequence the susceptibility for oxygen-glucose deprivation-induced glutamate receptor-mediated cell death is increased after glial cell-line derived neurotrophic factor treatment. In summary, we conclude that both ionotropic glutamate receptors and glutamate transporters are involved in oxygen-glucose deprivation-induced necrotic cell death in hippocampal slice cultures, which have proven to be a feasible tool in experimental studies on this topic.

Neurotoxic and neuroprotective effects of the glutamate transporter inhibitor DL-threo-beta-benzyloxyaspartate (DL-TBOA) during physiological and ischemia-like conditions.

Maintenance of low extracellular glutamate ([Glu](O)) preventing excitotoxic cell death requires fast removal of glutamate from the synaptic cleft. This clearance is mainly provided by high affinity sodium-dependent glutamate transporters. These transporters can, however, also be reversed and release glutamate to the extracellular space in situations with energy failure. In this study the cellular localisation of the glutamate transporters GLAST and GLT-1 in organotypic hippocampal slice cultures was studied by immunofluorescence confocal microscopy, under normal culture conditions, and after a simulated ischemic insult, achieved by oxygen and glucose deprivation (OGD). In accordance with in vivo findings, GLAST and GLT-1 were primarily expressed by astrocytes under normal culture conditions, but after OGD some damaged neurons also expressed GLAST and GLT-1. The potential damaging effect of inhibition of the glutamate transporters by DL-threo-beta-benzyloxyaspartate (DL-TBOA) was studied using cellular uptake of propidium iodide (PI) as a quantitative marker for the cell death. Addition of DL-TBOA for 48 h was found to induce significant cell death in all hippocampal regions, with EC(50) values ranging from 38 to 48 microM for the different hippocampal subregions. The cell death was prevented by addition of the glutamate receptor antagonists NBQX and MK-801, together with an otherwise saturating concentration of DL-TBOA (100 microM). Finally, the effect of inhibition of glutamate release, via reverse operating transporters during OGD, was investigated. Addition of a sub-toxic (10 microM) dose of DL-TBOA during OGD, but not during the subsequent 48 h recovery period, significantly reduced the OGD-induced PI uptake. It is concluded: (1) that the cellular expression of the glutamate transporters GLAST and GLT-1 in hippocampal slice cultures in general corresponds to the expression in vivo, (2) that inhibition of the glutamate transporters induces cell death in the slice cultures, and (3) that partial inhibition during simulation of ischemia by OGD protects against the induced PI uptake, most likely by blocking the reverse operating transporters otherwise triggered by the energy failure.

GDNF pre-treatment aggravates neuronal cell loss in oxygen-glucose deprived hippocampal slice cultures: a possible effect of glutamate transporter up-regulation.

Besides its neurotrophic and neuroprotective effects on dopaminergic neurons and spinal motoneurons, glial cell line-derived neurotrophic factor (GDNF) has potent neuroprotective effects in cerebral ischemia. The protective effect has so far been related to reduced activation of N-methyl-D-aspartate receptors (NMDAr). This study tested the effects of GDNF on glutamate transporter expression, with the hypothesis that modulation of glutamate transporter activity would affect the outcome of cerebral ischemia. Organotypic hippocampal slice cultures, derived from 1-week-old rats, were treated with 100 ng/ml GDNF for either 2 or 5 days, followed by Western blot analysis of NMDAr subunit 1 (NR1) and two glutamate transporter subtypes, GLAST and GLT-1. After 5-day exposure to GDNF, expression of GLAST and GLT-1 was up-regulated to 169 and 181% of control values, respectively, whereas NR1 was down-regulated to 64% of control. However, despite these changes that potentially would support neuronal resistance to excitotoxicity, the long-term treatment with GDNF was found to aggravate the neuronal damage induced by oxygen-glucose deprivation (OGD). The increased cell death, assessed by propidium iodide (PI) uptake, occurred not only among the most susceptible CA1 pyramidal cells, but also in CA3 and fascia dentata. Given that glutamate transporters are able to release glutamate by reversed action during energy failure, it is suggested that the observed increase in OGD-induced cell death in the GDNF-pretreated cultures was caused by the build-up of excitotoxic concentrations of extracellular glutamate released through the glutamate transporters, which were up-regulated by GDNF. Although the extent and consequences of glutamate release via reversal of GLAST and GLT-1 transporters seem to vary in different energy failure models, the present findings should be taken into account in clinical trials of GDNF.

[Buschke-Ollendorff syndrome. Connective tissue nevi in osteopoikilosis]. / Buschke-ollendorffs syndrom. Bindevaevsnaevi ved osteopoikilose.

We describe here a patient with Buschke-Ollendorff syndrome (BOS) and present a review of the literature. BOS is characterised by osteopoikilosis, small sclerotic changes in the bones, and by dermatofibrosis lenticularis disseminata, yellow-white nodules in the skin. It is a benign, hereditary condition, with no influence on the patient's health. Awareness of this condition is of importance, as the wrong diagnosis can lead to unnecessary worry for the patient and extensive costs for the health care system.

The metabotropic glutamate receptor agonist 1S,3R-ACPD stimulates and modulates NMDA receptor mediated excitotoxicity in organotypic hippocampal slice cultures.

The potential toxic effects of the metabotropic glutamate receptor agonist (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (ACPD) and its interactions with the N-methyl-D-aspartate (NMDA) receptor were studied in hippocampal brain slice cultures, using densitometric measurements of the cellular uptake of propidium iodide (PI) to quantify neuronal degeneration. Cultures exposed to ACPD, showed a concentration (2-5 mM) and time (1-4 days) dependent increase in PI uptake in CA1, CA3 and dentate subfields after 24 h and 48 h of exposure, with CA1 pyramidal cells being most sensitive. The neurodegeneration induced by 2 mM ACPD was completely abolished by addition of 10 microM of the NMDA receptor antagonist (5R,10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine (MK-801), while 20 microM of the 2-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA)/kainic acid receptor antagonist 2,3-dioxo-6-nitro-1,2,3,4-tetrahydrobenzo[f]quinoxaline-7-sulfonamide (NBQX) had no effect. Co-exposing cultures to a subtoxic dose of 300 microM ACPD together with 10 microM NMDA, which at this dose is known to induce a fairly selective degeneration of CA1 pyramidal cells, significantly increased the PI uptake in both CA1 and CA3, compared to cultures exposed to 10 microM NMDA only. Adding the 300 microM ACPD as pretreatment for 30 min followed by a 30 min wash in normal medium before the ACPD/NMDA co-exposure, eliminated the potentiation of NMDA toxicity. The potentiation was also blocked by addition of 10 or 100 microM 2-methyl-6-(phenylethynyl)pyridine (MPEP) (mGluR5 antagonist) during the co-exposure, while a corresponding addition of 10 or 100 microM 7-(hydroxyimino)cyclopropa[b]chromen-1a-carboxylate ethyl ester (CPCCOEt) (mGluR1 antagonist) had no effect. We conclude that, stimulation of metabotropic glutamate receptors with ACPD at concentrations of 2 mM or higher induces a distinct subfield-related and time and concentration dependent pattern of hippocampal degeneration, and that ACPD at subtoxic concentrations modulates NMDA-induced excitotoxicity through the mGluR5 receptor in a time dependent way.

GDNF and neublastin protect against NMDA-induced excitotoxicity in hippocampal slice cultures.

The potential neuroprotective effects of glial cell line-derived neurotrophic factor (GDNF) and neublastin (NBN) against NMDA-induced excitotoxicity were examined in hippocampal brain slice cultures. Recombinant human GDNF (25-100 ng/ ml) or NBN, in medium conditioned by growth of transfected, NBN-producing HiB5 cells, were added to slice cultures I h before exposure to 10 microM NMDA for 48h. Neuronal cell death was monitored, before and during the NMDA exposure, by densitometric measurements of propidium iodide (PI) uptake and loss of Nissl staining. Both the addition of rhGDNF and NBN-containing medium significantly reduced the NMDA-induced PI uptake in the CA1 (p < 0.01), suggesting neuroprotective effects of these factors, beyond their well-known trophic effects on dopaminergic neurons.

[Stricture of the colon induced by hyperthermia--in connection with irrigation via sigmoidostomy]. / Hypertermisk induceret colonstriktur--i forbindelse med irrigation via sigmoideostomi.

A case of thermal injury following the introduction of excessively hot tap water into the colon during irrigation of a sigmoid colostomy is described. The radiological proof of a subsequently developed colon stricture made it necessary to remove the injured part and reconstruct the colostomy. Only two other cases of this kind have been reported in English literature. The case emphasizes that care must be taken in selecting the right temperature of the water for irrigation.

Continuous infusion of recombinant activated factor VII: stability in infusion pump systems.

Recombinant activated factor VII (rFVIIa; NovoSeven, Novo Nordisk, Bagsvaerd, Denmark) has a half life of 2.8 h in vivo, necessitating frequent dosing to maintain haemostasis where administration is by bolus injection. Continuous infusion would avoid this frequent dosing and potentially reduce the amount of rFVIIa used and the cost of treatment. We investigated the stability of reconstituted rFVIIa solutions alone and with the addition of heparin, low-molecular-weight heparin (LMWH, enoxaparin) and saline solution. Recombinant FVIIa was stable in the infusion pump for several days at room temperature and for 24 h at body temperature. Addition of heparin at pH 7 and LMWH and saline did not significantly affect the activity of rFVIIa for periods of 2 h, 72 h and 30 min, respectively. Recombinant FVIIa continuous infusion systems prepared under strict aseptic conditions remained free from significant microbiological contamination for 24 h.

["Blue rubber bleb nevus syndrome"--or Bean's syndrome]. / "Blue rubber bleb naevus syndrome"--eller Beans syndrom.

We describe a case of the blue rubber bleb naevus syndrome, an uncommon systemic disorder characterized by multiple bluish haemangiomas of the skin and gastrointestinal tract. The syndrome is commonly associated with iron deficiency anaemia due to gastrointestinal bleeding. The syndrome is likely to be caused by a gene mapping to chromosome 9p and showing autosomal dominant inheritance. This is the first Danish report of this unusual disease. We hope that this case will heighten the awareness of this condition, because early recognition is essential for appropriate medical intervention and genetic counselling.

Rate dependence of regional cerebral activation during performance of a repetitive motor task: a PET study.

Using repeated positron emission tomography (PET) measures of regional cerebral counts, we investigated the regional cortical activations induced in eight normal subjects performing eight different frequencies of fingertapping (0.5-4 Hz) with the right index finger. The task was auditorially cued and the performance recorded during the scanning procedure. Performance evaluation showed increased error rates, during fingertapping, of high and low frequencies, and the best tapping performance was measured in the midrange of frequencies. Significantly activated areas (p < 0.05) of normalized cerebral counts were located in the left sensorimotor cortex (MISI), right motor cortex, left thalamus, right insula, supplementary motor area (SMA), and bilaterally in the primary auditory cortex and the cerebellum. Statistical evaluation showed a significant (p < 0.01) and positive dependence of cerebral activation upon movement rate in the contralateral MISI. There was no significant rate dependence of cerebral activation in other activated motor areas. The SMA and the right cerebellar hemisphere showed a more uniform activation throughout the tapping frequency range. Furthermore, we found a stimulus rate dependence of cerebral activation in the primary auditory cortex. We believe that the present data provide useful information for the preparation and interpretation of future motor activation studies of normal human subjects and may serve as reference points for studies of pathological conditions.