The modular architecture of protein-protein binding interfaces

Protein-protein interactions are essential for life. Yet, our understanding of the general principles governing binding is not complete. In the present study, we show that the interface between proteins is built in a modular fashion; each module is comprised of a number of closely interacting residues, with few interactions between the modules. The boundaries between modules are defined by clustering the contact map of the interface. We show that mutations in one module do not affect residues located in a neighboring module. As a result, the structural and energetic consequences of the deletion of entire modules are surprisingly small. To the contrary, within their module, mutations cause complex energetic and structural consequences. Experimentally, this phenomenon is shown on the interaction between TEM1-beta-lactamase and beta-lactamase inhibitor protein (BLIP) by using multiple-mutant analysis and x-ray crystallography. Replacing an entire module of five interface residues with Ala created a large cavity in the interface, with no effect on the detailed structure of the remaining interface. The modular architecture of binding sites, which resembles human engineering design, greatly simplifies the design of new protein interactions and provides a feasible view of how these interactions evolved.

The effect of condylectomy on extreme lateral transcondylar approach to the anterior foramen magnum

The dorsolateral, suboccipital, transcondylar technique was used in this cadaveric study. The angle and distance measurements in the corridors were taken intradurally both superior and inferior of the foramen magnum level. In the first stage of this study, the findings which were gained from the standard lateral suboccipital approach were compared with the findings after condyle and lateral atlantal mass removal. After condylectomy, the approach to anterior foramen magnum via both corridors was found to be shorter and the lateral angle of the exposure of the anterior foramen magnum was found to be wider. The considerable shortening of the distances to the anterior foramen magnum, especially in the superior corridor, emphasises the necessity of combining standard approaches with condylectomy. In addition, it was found that after condylectomy, considerable widening of both transverse and longitudinal planes in the inferior corridor allows the surgeon greater access to work on lesions. Furthermore, the freed space between the superior corridor and the interior corridor, which was gained by condylectomy, shows that condylectomy provides a combined approach to the inferior and superior parts of the foramen magnum anteriorly.

Post-traumatic bilateral diffuse cerebral swelling

This study confirms that bilateral diffuse cerebral swelling with or without parenchymal haemorrhages (< 15 cc) is a more common occurrence in the paediatric patients with severe head injury as compared with adults, since the analysed sample represented 42.55% and 20.43% of all paediatric and adult patients with severe head injury recorded in our clinic at the time of the study, respectively. The incidence of patients with diffuse cerebral swelling without parenchymal haemorrhages was found to be 27.65% of paediatric patients and 5.37% of adult patients with severe head injury. Secondary neurological deterioration occurred only in 5 (12.5%) paediatric patients and in 4 (10.5%) adult patients with diffuse cerebral swelling and was not to be found associated with parenchymal haemorrhages. A better outcome was seen in paediatric patients. Mortality rates were 12.5% in paediatric patients and 34.21% in adult patients. Our data also suggest that the mortality rate between paediatric and adult patients with diffuse cerebral swelling without parenchymal haemorrhages was similar (15.38% and 20% in paediatric and adult group, respectively), while the adult patients with diffuse cerebral swelling associated with small intraparenchymal haemorrhages have a worse prognosis than paediatric patients.

Proof of the patent subcutaneous fibrous tract in children with V-P shunt malfunction

A connective tissue sheath that forms around the peritoneal catheter of silicone ventriculo-peritoneal (V-P) shunt tubing is quite often observed in children with V-P shunts. However, proof of the passage of cerebrospinal fluid (CSF) through these sheaths has been reported in only one published study to date. We present four cases associated with chronic malfunction of the V-P shunt peritoneal catheter. In these cases, CSF passage through the subcutaneous fibrous tract, which had a pericatheter connective tissue sheath, was demonstrated around the V-P shunt peritoneal catheter. In the first case the patient suffered intermittent headache attacks over a long period of time; abdominal migration of the peritoneal catheter was detected. The second patient, who had been asymptomatic in the follow-up period with an outgrown peritoneal catheter, was admitted with acute hydrocephalus symptoms. A peritoneal catheter disconnection was detected in another patient, who had had multiple shunt revisions previously. In the last case, an obstruction of the peritoneal catheter was detected. The existence of the subcutaneous fibrous tract and its function were demonstrated by radio-opaque shuntogram in two cases and radionuclide shuntogram in the other two cases. In all four cases V-P shunt revision was performed. Within this study, the possible passage of CSF through a fibrous tract in cases of migration, outgrowth, disconnection or obstruction of the peritoneal shunt catheter was demonstrated. In conclusion, patients with shunt malfunction with a well-grown pericatheter fibrous sheath who are either asymptomatic or minimally symptomatic and show no evidence of active ventricular dilatation on their cranial CT scan should not be regarded as having arrested hydrocephalus until radio-opaque or radionuclide shuntogram studies have been done.

Demographic and Clinical Features of Pediatric Uveitis in Israel

Purpose: To report the epidemiology, etiology, ocular characteristics, treatment and visual outcome of pediatric uveitis in Israel.Methods: Retrospective study from two tertiary uveitis centers.Results: Included were 107 patients (182 eyes), 55% females. Mean age at diagnosis 8.8 years. Uveitis was predominantly anterior, idiopathic, bilateral, and chronic. Systemic associations were seen in 36% of patients of which the most common disease was juvenile idiopathic arthritis. Infectious uveitis accounted for 37% of posterior uveitis cases of which toxoplasmosis was the most common cause. Anterior segment complications were commonly observed at presentation (41%); the most predominant were posterior synechiae, cataract, and band keratopathy. The most common posterior segment complications were papillitis, epiretinal membrane, and macular atrophy/scar. Ninety-three percent of eyes had visual acuity >20/40 at last follow-up.Conclusion: The pattern of pediatric uveitis in Israel is similar to that in the western world. Visual outcome was good in most eyes.

Outcomes of Drug-Eluting Balloons for In-Stent Restenosis: Large Cohort Analysis and Single-Center Clinical Experience

BACKGROUND

The use of drug-eluting balloons (DEBs) remains clinically relevant in the contemporary era of drug-eluting stent percutaneous coronary interventions (DES-PCI), especially in the setting of in-stent restenosis (ISR). Our goal was to assess the outcomes of ISR patients in a large prospective registry.

METHODS

A total of 2329 consecutive patients with ISR-PCI (675 using DEB and 1654 with DES) were treated in our medical centre from 2010 to 2021. Clinical end points included mortality and major adverse cardiac events (MACE) at 1 year. Clinical outcomes were adjusted for multiple confounders.

RESULTS

Mean ages (65.9 ± 11.0 vs 66.1 ± 10.5; P = 0.73) and percentages of female patients (16.6% vs 18.2%; P = 0.353) were similar between both ISR groups. Patients treated with DEB for ISR suffered more from diabetes, hypertension, and previous myocardial infarction (P < 0.01 for all) and presented more frequently with acute coronary syndrome (40.0% vs 34.4%; P = 0.01) compared with patients treated with DES for ISR. One-year MACE was significantly higher in the DEB ISR-PCI group (23.4% vs 19.6%; P = 0.002) compared to the DES ISR-PCI group, but no significant differences in mortality were observed at 1 year between the groups. After adjustment for multiple confounders, DEB ISR-PCI was not associated with increased MACE at 1 year (P = 0.55).

CONCLUSIONS

In our large experience, patients treated with DEB for ISR-PCI have higher baseline risk and sustained increased MACE rates compared with DES ISR-PCI patients. After adjustment for confounding variables, clinical outcomes are similar between the groups at 1 year after PCI.

The Safety Profile of Amiodarone Among Older Adults (Age ≥75 Years): A Pharmacovigilance Study from the FDA Data

BACKGROUND

Amiodarone is a widely used antiarrhythmic agent with significant toxicities and drug interactions more likely to affect older adults. Nevertheless, data regarding amiodarone safety in this population are limited.

METHODS

We conducted a retrospective analysis of FDA [Food and Drug Administration] Adverse Event Reporting System (FAERS) data from 2003 to 2024. Reports with amiodarone as the primary suspect were compared with other antiarrhythmics (sotalol, dronedarone, flecainide, propafenone, dofetilide). Disproportionality analysis assessed reporting odds ratios (RORs) for predefined adverse events in adults (<75 years) and older adults (≥75 years). Interaction analysis evaluated differences between age groups.

RESULTS

Among 9196 amiodarone FAERS reports, 4129 (44.9%) involved older adults. Hyperthyroidism (ROR 39.1; 95% confidence interval [CI], 25-61 and ROR 23.4; 95% CI, 11-49.8) and hypothyroidism (ROR 36.9; 95% CI, 15.2-89.8 and ROR 24.5; 95% CI, 11.5-52.1) were substantially over-reported in amiodarone users among both adults and older adults, respectively. Drug-induced liver injury and peripheral neuropathy were also over-reported without a significant age interaction. Interstitial lung disease was reported more frequently in amiodarone users overall, with significantly higher reporting in older adults (ROR 11.4; 95% CI, 6.9-18.6 vs 4.9; 95% CI, 3.4-7.0; Pinteraction = .007). Bradycardia was also over-reported in older adults compared with adults (ROR 1.6; 95% CI, 1.3-2 vs 1.0; 95% CI, 0.8-1.3; Pinteraction = .003). Torsades de pointes/QT prolongation were less frequently reported in both age groups.

CONCLUSIONS

In this global postmarketing study, interstitial lung disease and bradycardia were more frequently reported in older adults treated with amiodarone. These findings support vigilant monitoring for these adverse events, particularly in older patients.

Long Term Efficacy and Safety of Cardiac Resynchronization Therapy in Adult Congenital Heart Disease Patients: A Single Center Cohort Study

Heart failure constitutes a major cause for morbidity amongst patients with adult congenital heart disease (ACHD). Cardiac resynchronization therapy (CRT) is a recommended therapeutic measure for patients with heart failure. Data on the efficacy and safety of CRT amongst patients with ACHD is limited. This study analyzed data from a retrospective cohort of patients with ACHD and implantation of CRT between 2015 and 2022. The primary outcome was echocardiographic response to CRT, defined as either: (1) an increase in systemic ventricular ejection fraction (EF) of ≥ 5% in patients with baseline EF <50% (therapeutic efficacy) or (2) maintenance of EF in patients with EF ≥ 50% (preventative efficacy). The outcomes were assessed by subgroups of systemic left or right ventricle ventricle. In a cohort of 45 patients, mean age was 54 ± 14 years, 26 patients had a systemic left ventricle (57.8%) and 19 patients had a systemic right ventricle (42.2%). The average follow-up was 5.2 ± 0.5 years. Primary outcome amongst patients with reduced EF at baseline was achieved in 69.0%; and in 92.3% amongst patients with preserved EF at baseline. There was no significant difference in the response to CRT as per systemic left or right ventricle (p = 0.15) or per baseline EF (p = 0.10). Complications occurred in 28.9% of patients. In conclusion, CRT appears to be effective in patients with ACHD in reducing rates of heart failure, regardless of baseline EF or systemic ventricle morphology. The percentage of patients with a safety outcome was relatively high and highlights the need for careful patient selection.

Short- and long-term outcomes of patients with active cancer presenting with an acute coronary syndrome

BACKGROUND

Management of cancer patients presenting with an acute coronary syndrome (ACS) may be challenging. In this study, we sought to examine whether and how a concomitant diagnosis of active cancer affects patients' management and outcomes following an event of ACS.

METHODS

We used a retrospective cohort data analysis of patients from the Acute Coronary Syndrome Israeli Survey (ACSIS) carried out between the years 2016-2021 to compare patients with and without a concomitant diagnosis of active cancer.

RESULTS

Of 4913 patients who presented with an ACS, 90 (1.8%) patients had a concomitant active cancer. Cancer patients were older, with a higher prevalence of hypertension and chronic renal failure. The rate of ST-elevation myocardial infarction (STEMI) was similar (40%) between both groups. Cancer patients were less likely to undergo coronary angiography during hospitalization; but once it was performed, the rate of percutaneous coronary intervention was similar. The presence of cancer during an ACS was associated with an increased short- and long-term mortality. In a multivariate analysis, the risk for 1-year mortality remained significantly higher in cancer patient (HR 2.72, 95% CI 1.74-4.24, p < 0.001), and was most prominent in patients presenting with STEMI (HR 5.00, 95% CI 2.40-10.39, p < 0.001). Short- and long-term death rates were also higher in cancer patients after a propensity score matching and adjustment for comorbidities other than cancer.

CONCLUSION

Despite significant advances in oncologic and cardiac care, the presence of active cancer in patients with an ACS is still associated with significantly increased risk for 1-year mortality.

Is 90 the new 80? Temporal trends in nonagenarians undergoing percutaneous coronary interventions

BACKGROUND

Coronary artery disease (CAD) is a leading cause of death in the elderly population. Data regarding percutaneous coronary interventions (PCIs) in nonagenarians are scarce, and differences in long term outcomes between generations remain unclear. We aimed to study the pattern and temporal trends of nonagenarians treated with PCI.

MATERIALS AND METHODS

A total of 14,695 patients underwent PCI between 2009-2020. We identified 2,034 (13.8%) octogenarians (age 80-89), and 222 (1.5%) nonagenarians (age 90-99). Endpoints included mortality and major adverse cardiac events (MACE) at 1 year.

MATERIALS AND METHODS

A total of 14,695 patients underwent PCI between 2009-2020. We identified 2,034 (13.8%) octogenarians (age 80-89), and 222 (1.5%) nonagenarians (age 90-99). Endpoints included mortality and major adverse cardiac events (MACE) at 1 year.

RESULTS

The number of nonagenarians undergoing PCI has increased substantially during the study time period, from 89 patients in the earlier time period (2009-2014) to 133 patients in the later time period (2015-2020). At 1-year, nonagenarians had significantly higher rates of both death (24.3% vs. 14.9%, p<0.01), and MACE (30.6% vs. 22.0%, p<0.01), as compared to octogenarians. The cumulative survival rate was higher among octogenarians both in the early and late time period (p<0.01 and p=0.039, respectively). A significant reduction in nonagenarian MACE rates were observed during the study time period, resulting in a non-significant difference in MACE rates in the later time period between both groups.

CONCLUSION

The number of nonagenarians who undergo PCI is on the rise. While their clinical outcomes are inferior as compared to younger age groups, improvement was noted in the late time period.

Empiric Usage of “Anti-Pseudomonal” Agents for Hospital-Acquired Urinary Tract Infections

Hospital-acquired urinary tract infection (HAUTI) is one of the most common hospital-acquired infections, and over 80% of HAUTI are catheter-associated (CAUTI). Pseudomonas aeruginosa, as well as other non-glucose fermenting Gram negative organisms (NGFGN, e.g., Acinetobacter baumannii), are frequently covered empirically with “anti-Pseudomonals” being administered for every HAUTI (and CAUTI). However, this common practice was never trialed in controlled settings in order to quantify its efficacy and its potential impacts on hospitalization outcomes. There were 413 patients with HAUTI that were included in this retrospective cohort study (2017–2018), 239 (57.9%) had CAUTI. There were 75 NGFGN infections (18.2% of HAUTI, 22.3% of CAUTI). P. aeruginosa was the most common NGFGN (82%). Despite multiple associations per univariable analysis, recent (3 months) exposure to antibiotics was the only independent predictor for NGFGN HAUTI (OR = 2.4, CI-95% = 1.2–4.8). Patients who received empiric anti-Pseudomonals suffered from worse outcomes, but in multivariable models (one for each outcome), none were independently associated with the empiric administration of anti-Pseudomonals. To conclude, approximately one of every five HAUTI (and CAUTI) are due to NGFGN, which justifies the practice of empiric anti-Pseudomonals for patients with HAUTI (and CAUTI), particularly patients who recently received antibiotics. The practice is not associated with independent deleterious impacts on outcomes.