Discovery of Nanomolar DCAF1 Small Molecule Ligands

DCAF1 is a substrate receptor of two distinct E3 ligases (CRL4DCAF1 and EDVP), plays a critical physiological role in protein degradation, and is considered a drug target for various cancers. Antagonists of DCAF1 could be used toward the development of therapeutics for cancers and viral treatments. We used the WDR domain of DCAF1 to screen a 114-billion-compound DNA encoded library (DEL) and identified candidate compounds using similarity search and machine learning. This led to the discovery of a compound (Z1391232269) with an SPR KD of 11 μM. Structure-guided hit optimization led to the discovery of OICR-8268 (26e) with an SPR KD of 38 nM and cellular target engagement with EC50 of 10 μM as measured by cellular thermal shift assay (CETSA). OICR-8268 is an excellent tool compound to enable the development of next-generation DCAF1 ligands toward cancer therapeutics, further investigation of DCAF1 functions in cells, and the development of DCAF1-based PROTACs.

Linear versus Nonlinear Muscle Networks: A Case Study to Decode Hidden Synergistic Patterns During Dynamic Lower-limb Tasks

This paper, for the first time, compares the behaviors of nonlinear versus linear muscle networks in decoding hidden peripheral synergistic neural patterns during dynamic functional tasks. In this paper, we report a case study during which one healthy subject conducts a series of four lower limb repetitive tasks. Specifically, the paper focuses on tasks that involve the right knee joint, including walking, sit-tostand, stepping, and drop-jump. Twelve muscles were recorded using the Delsys Trigno system. The linear muscle network was generated using coherence analysis, and the nonlinear network was generated using Spearman's correlation. The results show that the degree, clustering coefficient, and global efficiency of the muscle network have the highest value among tasks in the linear domain for the walking task, while a low linear synergistic network behavior for the sit-to-stand is observed. On the other hand, the results show that the nonlinear functional muscle network decodes high connectivity (degree) and clustering coefficient and efficiency for the sit-tostand when compared with other tasks. We have also developed a two-dimensional functional connectivity plane composed of linear and nonlinear features and shown that it can span the lower-limb dynamic task space. The results of this paper for the first time highlight the importance of observing both linear and nonlinear connectivity patterns, especially for complex dynamic tasks. It should also be noted that through a simultaneous EEG recording (using BrainVision System), we have shown that, indeed, cortical activity may indirectly explain highly-connected nonlinear muscle network for the sit-to-stand task, highlighting the importance of nonlinear muscle network as a neurophysiological window of observation beyond the periphery.

Telehealth for consultation and shoulder rehabilitation: a preliminary study on the perspectives of 30 patients during the COVID-19 lockdown

BACKGROUND

This study aimed to determine: the perspectives of the patient cohort that underwent telehealth consultation and shoulder rehabilitation during coronavirus disease 2019 (COVID-19) and the differences in the patients' perspectives with the two different telehealth video applications (apps) used in the study.

METHODS

This is a prospective study carried out during the COVID lockdown period of April to July 2020. Thirty consecutive patients from the orthopedics department of a tertiary institute in India underwent their first-ever session of a video app-based (Zoom or WhatsApp) telehealth consultation with shoulder rehabilitation exercises on a handheld mobile, tablet, or laptop device. After the virtual consultation, the patients were sent a validated telehealth usability questionnaire (TUQ) to evaluate their perspectives. Scores obtained from the TUQ were the primary outcome measure.

RESULTS

The study was completed by 30 patients (16 men and 14 women) with an average age of 56 years (range, 20-77 years). The patients who contacted us during the lockdown period with either a stiff shoulder or a conservatively treated shoulder fracture were included in the study. The average TUQ score was 13.6 (median, 14.5; range, 6-21) out of a maximum of 21 points. Eighty percent of the patients were satisfied and found the telehealth service useful. Use of the Zoom app scored significantly higher (median, 17; average, 15.6) than the WhatsApp app (median, 8.5; average, 9.6) (p=0.004).

CONCLUSIONS

Patients who received telehealth consultation and shoulder rehabilitation were overall satisfied. Telehealth apps with advanced video calling features such as Zoom should be preferred for higher patient satisfaction.

Enhancing mutant IKS channel activity by increasing endogenous PIP2 levels and its interaction with PKA signalling pathway

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): British Heart Foundation

Phosphatidylinositol-4,5-biphosphate (PIP2) is implicated in the regulation and modulation of the IKS channel. The channel is formed at the plasma membrane by the co-assembly of KCNQ1 and KCNE1. Patients with Congenital Long QT 1(LQT1) syndrome are predisposed to Polymorphic VT due to mutations in KCNQ1, leading to impaired channel activity.

We initially transfect Human Embryonic Kidney (HEK) cells with a mammalian vector expressing KCNQ1 gene tagged with green fluorescent protein, along with KCNE1 to form the wild type (WT) IKS channel. The cells were also transfected with a constitutively active PI(4)P 5-kinase(PIP5K), which converts the phospholipid Phosphatidylinositol-4-phosphate to PIP2, therefore increasing endogenous levels of PIP2. To ensure the enzyme remains localised at the plasma membrane we attached it to CFP-FKBP and we co-transfected the cells with Lyn11-FRB construct that tethers to the plasma membrane. When these cells were perfused with Rapamycin it induced chemical dimerization of CF-PIP5K to lyn11. We utilised an inactive PIP5K as a control. Mutants were created with a site directed mutagenesis kit.

In the presence CF-PIP5K, whole cell voltage clamp recordings demonstrated a 2.5 fold statistically significant increase in WT channel activity (at +80mV,p < 0.001), when compared to unaltered PIP2 conditions. Heterozygous Serine566phe and Phe340del mutants had statistically significant reduction in current density compared to wild type in basal conditions. When these mutants were expressed with the active CF-PIP5K, Serine566phe and Phe340 had a 2.97 and 3.30 fold increase in current density, respectively (p <0.05). Homozygous Mutants D242N and T247in also showed statistically significant channel activity.

We substituted serine with alanine at site 27 and 92(S27A/S92A) to generate a mutant known to disrupt cAMP mediated upregulation, there was a statistical 3.3 fold (80 + mV) increase in current density when co-expressed with CF-PIP5K. We then substituted serine with aspartic acid (S27D/S92D) to create a Phosphomimetic mutation, this mutant reproduces the effects of sympathetic mediated augmentation of IKS channel. In the presence of enhanced PIP2 levels, the S27D/S92D failed to demonstrate a statistical increase in current, implying the channel is at its maximum activity and hence we failed to observe any further modulation.

We then proceeded to interrogate how PIP2 interacts with sympathetic signalling system. Pseudojanin(PJ) causes depletion of PIP2 hence perturbing channel activity. When PJ was expressed with KCNQ1 and KCNE1 we observed an 80% reduction in channel activity at +80mV(P <0.001). When we perfused these cells with isoprenaline the channel activity was restored to normal.

Here we illustrate how increasing PIP2 levels can revive IKS channel activity in mutant genotype, therefore supporting evidence of its capabilities as a potential therapeutic tool. This modulation is independent of the PKA-cAMP system. Abstract Figure. Current Increment

Can We Innovatively Modify the Surgical Helmets to Protect Against the Droplets and Aerosols of COVID-19?

We tested the filtration efficiency of Stryker T5 surgical helmets with and without the addition of a filter medium. Two particle counters were used to count the particles of sizes .5 μm, 1 μm, and 5 μm, both inside and outside the Stryker T5 helmet, concurrently. The total inward leakage (TIL) for the helmet with and without the filter was zero for 5 μm particles at all time points. The TIL (3.4) for the .5 μm particles decreased significantly after application of the filter (1.7; P = .007). We recommend that an N95 should be used inside the helmet system.

Results and complications of head-preserving techniques in chronic neglected shoulder dislocation: a systematic review

BACKGROUND

Humeral head-preserving procedures may be needed for chronic neglected shoulder dislocation because the presenting age of the patient is often reported to be less than 45 years. The aim of this systematic review was to evaluate the results of the various head-preserving procedures for chronic anterior dislocation (CAD) and chronic posterior dislocation (CPD). This review also aimed to evaluate the results of conservative neglect for CAD.

METHODS

PubMed, Embase, and Cochrane library databases were queried for studies that reported on results of head-preserving procedures for CAD or CPD and for studies that reported on the results of conservative neglect for CAD. Case reports, review articles, acute dislocations, and fracture-dislocations were excluded. The results of the different techniques were pooled for further evaluation.

RESULTS

Seventeen studies were selected for qualitative analysis. These were further subdivided into 9 studies for the CAD group and 11 studies for the CPD group. In the CAD intervention group, 53 shoulders in 7 studies were managed by 5 different head-preserving techniques. The choice of procedure to stabilize the shoulder after open reduction varied between coracoid transfer, capsulolabral repair, remplissage, and Putti-Platt procedure and acromiohumeral K-wire fixation. High resubluxation rates and early arthrosis were reported after open reduction techniques for CAD. In the CAD conservative group, 8 shoulders in 2 studies were managed by conservative methods. In the CPD group, the 2 most common techniques, McLaughlin or modified McLaughlin and bone grafting, were used to treat 74 shoulders in 7 studies and showed good functional outcomes.

CONCLUSION

The choice of open reduction and stabilization technique for CAD was highly variable between the different studies and led to a wide variation in the reported outcomes with a high number of complications such as resubluxation and early arthrosis. The conservative treatment of CAD led to poor functional results. The choice of treatment for CPD was mostly between 2 techniques-McLaughlin and modified McLaughlin reconstruction or the bone graft reconstruction-and they consistently led to good functional outcomes with less complications.

Instability, complications, and functional outcomes after reverse shoulder arthroplasty and anatomic shoulder arthroplasty for chronic neglected shoulder dislocation: a systematic review

Background

Chronic shoulder dislocation has been treated by either anatomic shoulder arthroplasty (ASA) or reverse shoulder arthroplasty (RSA) with encouraging results. Although good results have been reported after both the procedures, several complications such as instability and glenoid failures have also been highlighted. The aim of this study was to aggregate the results that have been reported with the use of ASA or RSA in chronic shoulder dislocation and analyze the instability rates, complication rates, and functional outcomes.

Methods

A comprehensive search was performed in May 2020 using PubMed, EMBASE, and Cochrane Library databases. Studies that reported on the outcomes after either ASA or RSA for chronic anterior dislocation (CAD) or chronic posterior dislocation (CPD) were included in the systematic review. Methodologic quality was assessed using the Methodological Index for Nonrandomized Studies appraisal tool for observational studies.

Results

We aggregated 13 studies that included data on 128 patients with CAD and 51 patients with CPD. The combined weighted postoperative instability rate in the CAD group was significantly higher after ASA than after RSA (P = .04). There was no significant difference in the combined weighted instability rate between ASA in the CAD group and ASA in the CPD group (P = .37). The complications of RSA in CAD included glenoid base plate loosening, humeral shaft fractures, late infection, acromion fractures, and instability. The complications of the ASA in CAD and CPD included glenoid loosening and erosions, severe pain necessitating revision, severe superior migration of the head, redislocation with rupture of the cuff tendons, bone graft migration, instability, and 2 cases of neuropathies (median nerve and axillary nerve) that eventually resolved.

Conclusion

Postoperative instability was significantly more common after ASA than after RSA for chronic shoulder dislocations, but both RSA and ASA had a high complication rate in CAD. Shoulder arthroplasty improved the range of motion, functional outcomes, and pain in patients with chronic shoulder dislocation.

Geometric analysis of the humeral head and glenoid in the Indian population and its clinical significance

BACKGROUND

Total anatomic and reverse shoulder prostheses are designed to match the dimensions of the native bony anatomy. Chinese and Japanese bony dimensions of the shoulder have been found to be different from that of the Caucasian population. We hypothesized that the geometric dimensions of the humeral head and glenoid in the Indian population would also be different from that of the Caucasian population.

METHOD

Fifty patients underwent computerized tomographic scans of their normal shoulders. We calculated the superoinferior (SI) diameter of the humeral head, anteroposterior diameter of the humeral head, radius of curvature of the humeral head, humeral head retroversion, humeral head thickness, inclination angle, critical shoulder angle, greater tuberosity angle, glenoid width, glenoid length, radius of curvature of the glenoid, glenoid inclination angle, and glenoid version.

RESULTS

The radius of curvature of the humeral head averaged 22.9 ± 1.7 mm, the articular surface thickness 17.1 ± 1.6 mm, and the SI diameter 42.3 ± 3 mm. The SI diameter strongly correlated with the thickness (r = 0.617, P = .001). The anteroposterior/SI articular surface diameter ratio averaged 0.9 ± 0.9, the articular surface thickness/radius of curvature ratio 0.7 ± 0.9, the inclination angle 133.8 ± 6.4, and the retroversion angle 33.5° ± 8.5°. The radius of curvature of the glenoid averaged 23.3 ± 3.4 mm, the glenoid width 24.0 ± 2 mm, the SI length 31.3 ± 2.2 mm, the glenoid inclination angle 78.7° ± 4.8°, and the glenoid retroversion 1.8° ± 3.8°.

DISCUSSION

Compared with the Western population, our cohort had a smaller humeral radius of curvature (P = .04), smaller articular surface diameter (P = .001), smaller inclination angle (P = .003), larger retroversion angle of the humeral head (P < .001), and smaller glenoid length and width (P < .0001). Most of the implant companies did not have smaller sized combinations of humeral heads with thickness to match our population. The glenoid width of females in our cohort was found to be smaller for the smallest size of the glenoid base plate.

CONCLUSION

Smaller sized options in humeral head diameter and thickness of the anatomic prosthesis and glenoid baseplate of the reverse shoulder prosthesis need to be made available to suit our population and avoid a mismatch.

Impact of COVID 19 lockdown on orthopaedic surgeons in India: A survey

BACKGROUND

In the fight against COVID 19, the government of India announced a 3 weeks lockdown of the entire country of 1.3 billion people on 24th March 2020.

METHODS

One week after the lockdown was announced, we conducted an anonymous online survey of the orthopaedic surgeons in India through social media platforms to assess the impact of the lockdown during COVID 19. The survey had a total of 13 questions with (3-5) options and was designed with an aim to understand the perception and the state of mind of the Orthopaedic surgeons in the lockdown situation.

RESULTS

The survey was completed by 611 orthopaedic surgeons from 140 cities in India. There were 22.5% orthopaedic surgeons who said that they were definitely stressed out, and 40.5% who said they were mildly stressed out. As the age decreased, the percentage of orthopaedic surgeons feeling "definitely stressed out" increased. Disruption of life-work balance and uncertainties regarding return to work were other strongly associated factors with the "definitely stressed out" group.

CONCLUSION

The psychological impact of the lockdown during COVID 19 on orthopaedic surgeons may become a potential concern that will require addressal through open discussion.

LEVEL OF EVIDENCE

diagnostic level 4.

57Fe internal field nuclear magnetic resonance and Mössbauer spectroscopy study of Li-Zn ferrites

We report the internal field nuclear magnetic resonance (IFNMR) and Mössbauer spectroscopy study of Li-Zn ferrites at RT. The results were supported by the IFNMR data measured at 77 K. As Zn concentration increases the IFNMR echo amplitude decreases and below certain Zn concentration no signal was detected. At RT the echo amplitude vanishes at a lower Zn concentration, whereas at 77 K, the echo amplitude does not vanish completely (except for pure Zn-ferrite). However, in Mössbauer spectroscopy at RT, we have observed magnetically ordered state of all the Li-Zn ferrite samples. This discrepancy could be related to the difference between the time scale of detection of the spins by Mössbauer spectroscopy (10^-7-10^-10 s) and NMR spectroscopy (10^-6 s). Hence, sensitivity of zero-field NMR depends on the magnetic hyperfine field, temperature and abundance of the magnetic cations at the lattice of the spinel ferrites. We have demonstrated that the 'two-equal-pulses' sequence leads to higher echo signal than the spin echo pulse sequence due to the presence of distribution of internal magnetic fields throughout the material. We obtained a limiting value for the fraction of spins needed to produce an echo signal at a particular temperature and at a particular site of the Li-Zn ferrite spinels that can be sensitively detected by pulsed IFNMR technique.

Effect of water extract of the bark of Buchanania lanzan linn. on behaviour and chromatophores of a fresh water fish, Labeo rohita

Fish exposed to 150 ppm and 250 ppm doses saparately, showed eratic swimming with hyper-excitability, spiralling, convulsion and mortality. However at 350 ppm dose fish became lethargic and steady at the bottom of aquarium. This behaviour appears to be due to sedative effects of fish implicating the phychoactive nature of the plant B. Ianzan. At 150 ppm to 350 ppm doses, fish scale changed from reticulate to punctate chromatophores; and treated fish when transferred to fresh water, were slowly regained to normal behaviour after 96 h exposure. Hence doses regaining from 150 ppm to 350 ppm is considered to be psychoative in nature. In higher doses 450 ppm and 550 ppm fish could survive only 76 h and 4.30 h respectively and then died indicating toxicity of plant for the said doses. It is found that scale present on its body is most suitable test system for the study of psychoactivity and toxicity of plant extracts on fish, Labeo rohita.

Stent retriever for dilation of pancreatic and bile duct strictures. brand@uke.uni-hamburg.de

BACKGROUND AND STUDY AIMS

Dilation of high grade strictures of pancreatic or biliary ducts using dilating or balloon catheters may fail. We evaluated the efficacy of the 7-Fr Soehendra Stent Retriever used as a dilator.

PATIENTS AND METHODS

Following sphincterotomy, the stricture was first negotiated with a 260 cm long 0.032-inch J-type Terumo wire. Dilation was then attempted using a 7-Fr dilating catheter. If the stricture could not be traversed, the 7-Fr Stent Retriever was inserted over the Terumo wire to dilate the stricture. Between May 1996 and January 1997, the Stent Retriever was used for dilation in 32 patients with biliary or pancreatic duct strictures.

RESULTS

The indication for therapeutic endoscopic retrograde cholangiopancreatography (ERCP) was symptomatic chronic pancreatitis in 21 patients (twelve men, nine women; mean age 45.7, range 26-70). The mean length (+/-SD) of the pancreatic duct strictures was 20mm+/-10 (range 3-55) with a prestenotic ductal diameter of 9mm+/-2 (range 2-15). Out of 21 patients, nine suffered from pancreaticolithiasis and were treated with extracorporeal shock wave lithotripsy. All but three patients underwent successful stenting in the same session. Another 11 patients (four men, seven women; mean age 67.4, range 47-85) had cholestasis because of benign or malignant bile duct strictures. The mean length of the strictures was 20mm+/-5 (range 3-40), and the mean prestenotic diameter was 10mm+/-5 (range 4-21). Stenting was easily done in all of these patients in the same session. Symptom relief was observed within the first week after stenting in all patients with a biliary or pancreatic stricture. In seven cases, material for cytological examination was obtained from the bile duct, which revealed malignancy in two cases. There was no complication associated with the use of the Stent Retriever. One subcapsular liver perforation was caused by the guide wire and occurred prior to the use of the Retriever.

CONCLUSIONS

Tight pancreatic and bile duct strictures can be dilated successfully with the Stent Retriever. The procedure is of low risk. In addition, tissue sampling is possible in some cases.

Biotechnological production of oil: fatty acid composition of microbial oil

The fatty acid profile and the fatty acid composition of microbial lipids obtained from molds revealed that oil from Aspergillus sydowii, Fusarium oxysporum and F. equisetti had a high percentage of unsaturated fatty acids, particularly oleic acid, and had a similarity to the edible oils, groundnut and palm oil. This study sheds light on the possibilities of exploring the use of these oils as supplement to other edible fats and for other non-edible industrial purposes.

EUS-guided, fine-needle aspiration biopsy using a new mechanical scanning puncture echoendoscope

BACKGROUND

A new mechanical sector scanning echoendoscope designed for EUS-guided, fine-needle aspiration biopsy (FNAB) was prospectively evaluated. The technical feasibility, safety, and histocytologic FNAB results are reported.

METHODS

Eighty-six patients underwent 106 FNAB procedures. The new echoendoscope has a 2.8 mm accessory channel and an elevator. Target sites: pancreas 58, lymph nodes 43, and miscellaneous lesions 5. Lesions were punctured with a 0.7 mm needle and submitted for cytologic and histologic examination. Definitive diagnosis was by surgery or clinical follow-up.

RESULTS

The wide scanning field (250 degrees) enabled easy sonographic orientation for FNAB. Longitudinal needle visibility was "good" in 93% and 71% of transesophageal and transgastric procedures, respectively, but were compromised during most transduodenal procedures. Needle penetration of indurated pancreatic lesions failed in two patients, and in four additional patients pancreatic sampling succeeded only after a second attempt using an automated spring-loaded device. The mean number of passes was three. Ten percent of FNAB specimens were "inadequate"; excluding these, the diagnostic accuracy rate was 97%; sensitivity for malignancy was 88.5% and specificity was 100%.

CONCLUSION

EUS-guided FNAB is feasible, safe, and accurate using the new mechanical puncture echoendoscope. Needle visibility needs to be improved, particularly for transduodenal FNAB.

Endoscopic ultrasound-guided, 18-gauge, fine needle aspiration biopsy of the pancreas using a 2.8 mm channel convex array echoendoscope

BACKGROUND

Previous studies have reported on endoscopic ultrasound-guided, fine needle aspiration biopsy using 22- to 25-gauge needles. We evaluated the histologic and cytologic yield of endoscopic ultrasound-guided, fine needle aspiration biopsy of the pancreas using an 18-gauge, Menghini-type core needle.

METHODS

Fine needle aspiration biopsy was performed in conjunction with a prototype 2.8 mm channel convex array echoendoscope. The core specimen was placed in formalin for cell block, and residual material was expelled on slides for cytology. Definitive diagnosis was established by surgery or clinical follow-up.

RESULTS

Of 45 patients who underwent fine needle aspiration biopsy, the needle failed to penetrate indurated pancreatic lesions in five. An average of 2.6 passes were performed in the remaining patients. Sufficient material for a histologic and/or cytologic diagnosis was obtained in 40 patients (histologic and cytologic yield of 68% and 75%, respectively). Combining the results of histology and cytology, the sensitivity and specificity for detection of malignancy was 76% and 100%, respectively. Histology confirmed the cytologic findings in 35 patients, providing additional tissue specific information. In three cases histology established a diagnosis of malignancy where cytology was not conclusively malignant. However, in three cases of surgically confirmed malignancy histology failed to detect malignancy, whereas cytology showed suspicious or malignant cells. The sensitivity of histology and cytology alone in detecting malignancy was 53% and 70%, respectively. Mild pancreatitis occurred after pancreatic fine needle aspiration biopsy in one patient.

CONCLUSION

Core specimens for histology can be safely obtained using an 18-gauge needle. Histology provides tissue-specific information that complements cytology, but histology is less sensitive than cytology in detecting malignancy.