Sepsis Unveils T-cell Large Granular Lymphocytic Leukemia in the Setting of End-Stage Renal Disease: A Rare Hematologic Malignancy.

Large granular lymphocytic (LGL) leukemia is a rare chronic lymphoproliferative disorder originating from natural killer cells or T lymphocytes. In this report, we present the case of a 66-year-old female initially treated for sepsis, with methicillin-sensitive Staphylococcus aureus identified on initial blood culture prompting intravenous (IV) antibiotic therapy. The patient met systemic inflammatory response syndrome criteria upon admission due to severe neutropenia. Persistent fever led to neurological symptoms, and imaging revealed lung abnormalities along with chronic changes on the CT scan of the head. Multidisciplinary consultations were sought, resulting in treatment adjustments including antifungals and filgrastim. Flow cytometry and bone marrow biopsy confirmed the diagnosis of LGL leukemia.

Long-term quality of life and work ability among severe COVID-19 survivors: A multicenter study.

Background: Coronavirus disease 2019 (COVID-19), is known for its variable severity and high infectivity. Though fewer than 15% of infected cases develop severe disease, a major proportion had prolonged stay in the intensive care unit (ICU). Prolonged ICU stay is known to have a long-term impact on behavior and quality of life.8 Therefore, it is likely that patients discharged after severe COVID-19 have issues that persist for long term. The current study aimed to assess the long-term impact of severe COVID-19 on the Quality of life (QOL), sleep pattern, behavior, and workability. Methods: The current multicenter study adopted a cross-sectional design to analyze data from two tertiary care COVID-19 dedicated hospitals. All experimental procedures were approved by the ethics committee of the M.L.B Medical College. Participants were 20-60 age group who had been admitted to the ICU because of severe COVID-19 and had elapsed at least one and a half year since their discharge. After informed written consent the participants were assessed for: EUROHIS-QOL 8-item index; Workability Score; Quality of sleep; The major depression inventory (MDI) questionnaire; Generalized anxiety disorder 7 item scale (GAD-7); Current global health status score: an innovative subjective scale (1 -10) to determine the current global health status when 5 is the status before COVID-19. Findings: 491 participants were assessed, the median follow-up time after discharge from the hospital was 561·0 days (range, 548-580 days). The mean duration of ICU stay was 8.72 ± 2.85 days. There was significant reduction in the prevalence of obesity, diabetes, and hypertension as compared with discharge time. The mean of EUROHIS-QOL score, workability score, current global health status score was 3.28 ± 0.98, 6.87 ± 0.85, 4.53 ± 1.36 respectively. The mean MDI and anxiety scores were 4.12 ± 1.45 and 18.63 ± 3.28, respectively. Interpretation: Severe COVID-19 survivors have new-onset psychological disorders and sleep disturbances. Long term quality of life and work ability remains poor after prolong ICU admission secondary to severe COVID-19.

Accuracy and Validity of Sharma's Venn Diagram Method for Assessment of Tibial Component Rotation in Total Knee Arthroplasty.

Background: Malrotation of the tibial component in a total knee replacement leads to anterior knee pain, patella dislocations, extensor mechanism disruptions, knee stiffness and prosthesis loosening. Techniques like free-floating technique, medial 1/3 rd of the tibial tubercle, medial border of the tibial tuberosity, Akagi's line, transcondylar line of tibia, posterior condylar line of tibia, midsulcus of tibial spines, curve on curve technique have been advocated. None of these have been shown to be accurate and reproducible. We developed a novel 'Sharma's Venn Diagram' method to assess the tibial component rotation. Methods: Fifty-two consecutive knee replacements were included in a prospective observational study. The average age of the study group was 53.6 years (48-76 years) Thirty-one were females and 3 were males. The patients were followed a minimum of one years (max 2 years, average 1.8 years). 'Sharma's Venn diagram Method (C)' was compared to free-floating method (F) and post-op CT scans using Berger protocol (B). Results: Tibial rotation calculated using Sharma's Venn diagram method (C) coincided with the final component placement in 50/52 knees. The free floating method (F) coincided with method (C) in 30/52 knees with an average 4.8° external rotation in 5 knees and an average of 5.2° internal rotation in 17 knees. Bland Altman method was used to compare method (C) with Method (F), The difference was statistically significant p < 0.0001. Conclusion: Sharma's Venn diagram method is reliable, accurate and easily reproducible by any surgeon performing tkr and correlates with postoperative 2D CT-based assessment of tibial component rotation. Level II Study: Prospective observational study.

Classification-Based Management of Stiff/Ankylosed Knees.

INTRODUCTION: Stiff knees are defined as those with an arc of motion < 50°. They pose a considerable surgical challenge to the operating surgeon. Based on our experience to deal with these complex cases, we have developed a working classification that outlines a flowchart to manage the stiff/ankylosed knees. MATERIALS AND METHODS: It was a retrospective study conducted in our department. Out of 570 TKA performed in last 5 years, 57 had stiffness and four had bony ankyloses (total 61 knees). Patients were classified based on the fibrous or bony ankylosis and preoperative ROM. RESULTS: Patients were followed for an average 2.4 years (1.8-5.5 years). KSS pain scores improved from an av. 32 preop (18-64) to av. 76 postoperatively (61-90). The KSS function scores improved from a preoperative value of 36 (16-56) to an av. 78 (52-90) postoperatively. ROM improved from an average of 35.6° (0°-44°) preoperatively to an average of 95.6° (ROM 73°-118°) postoperatively. Extension lag was an av. 8° (3°-12°) and was seen in 13 patients postoperatively. Residual fixed flexion deformity was an av. 7° (3°-14°) and seen in 17 patients. The stiff knees (type 1 and type 2) fared better than ankylosed knees (type 3) in all aspects. Complication rate was high (24%) in our series. CONCLUSION: Our classification of stiff/ankylosed knees guides the surgeon to decide upon which approach to take, which implants to keep handy and has a predictive and prognostic value.

Clinico-Radiological and Functional Results of the Navigated Gradius (Gradually Reducing Radius) Knee Prosthesis at Short to Mid-Term Follow-Up.

BACKGROUND: Navigated total knee replacements (TKR) have shown better knee function and quality of life. It also reduces revision rates. The aim of our study is to evaluate short to mid-term clinico-radiological and functional results, survival rate and complications of Gradius knee prosthesis implanted using computer navigation. METHODS: We retrospectively reviewed 120 Gradius knee prosthesis, implanted in 68 patients (52 bilateral TKR and 16 unilateral TKR) and followed from Jan 2015 till Jan 2020. Pre-operative & post-operative radiographs, knee society scores (KSS), range of motion (ROM), deformity assessment and gait video recordings were done for all patients. RESULTS: The mean follow-up was 3.8 years (minimum 2-5 years).The mean ROM was 2° (0-10) extension to 135° (128°-138°) flexion. The KSS pain score improved from mean of 38.3 (range 26-44) to 90.4 (mean 88-92). The KSS functional score improved from 36.2 (range 28-39) to 92.6 (range 86-94). All patients had excellent to good function during successive follow-ups. The coronal alignment improved from 8° varus to 0.3° varus. Sagittal alignment was corrected from 8° (4°-18°) preoperatively to 2° (0°-8°) postoperatively. CONCLUSION: At mid-term our series outlines the better functional and radiological results of Gradius knee prosthesis using navigation as a tool. We recommend a prospective randomized controlled trials comparing navigated versus non-navigated for Gradius knee prosthesis with long-term follow-up.

Probing the effects of double mutations on the versatile protein ubiquitin in Saccharomyces cerevisiae.

Ubiquitin is an indispensable protein of eukaryotic origin with an extraordinarily high degree of sequence conservation. It is used to tag proteins post-translationally and the process of ubiquitination regulates the activity of the modified proteins or drives them for degradation. Double mutations produce varied effects in proteins, depending on the structural relationship of the mutated residues, their role in the overall structure and functions of a protein. Six double mutants derived from the ubiquitin mutant UbEP42, namely S20F-A46S, S20F-L50P, S20F-I61T, A46S-L50P, A46S-I61T, and L50P-I61T, have been studied here to understand how they influence the ubiquitination related functions, by analysing their growth and viability, Cdc28 levels, K-48 linked polyubiquitination, UFD pathway, lysosomal degradation, endosomal sorting, survival under heat, and antibiotic stresses. The double mutation L50P-I61T is the most detrimental, followed by S20F-I61T and A46S-I61T. The double mutations studied here, in general, make cells more sensitive than the wild type to one or the other stress. However, the excessive negative effects of L50P and I61T are compensated under certain conditions by S20F and A46S mutations. The competitive inhibition produced by these substitutions could be used to manage certain ubiquitination associated diseases.

Role of Anatomical Patella Replacement on Anterior Knee Pain.

BACKGROUND: Anterior knee pain (AKP) remains a complex issue affecting patient satisfaction after total knee arthroplasty. Several radiographic parameters have been shown to be causative factors with various designs. The aim of this study is to evaluate the known radiographic parameters of AKP and clinical outcomes (ie, AKP) in the setting of a modern prosthesis with an anatomic patella button. METHODS: Between July 2012 and December 2013, 90 total knee arthroplasties received 3 skyline views taken at 30°, 45°, and 60°. A patient-administered questionnaire was administered at 2-year follow-up to assess the incidence of AKP, painless noise, and satisfaction. Radiographs were analyzed for patellofemoral overstuffing, patellar tilt, and patellar displacement, and evaluated the patella resection angle. RESULTS: On the patient-administered questionnaire, 10 (11.1%) patients reported AKP of a mild-to-moderate nature. Thirty-one had the best view at 30 Merchant views, 24 had best views at 45, and 35 had best views at 60. We found that patellar resection angle correlated with AKP (odds ratio 1.21, P = .044) and painless noise (odds ratio 1.22, P = .034). Patellar displacement and patellofemoral stuffing did not correlate with AKP or painless noise. No radiographic measurements correlated with changes in Knee Society Score pain or function scores or range of motion. CONCLUSION: We found that a patellar resection angle correlated with the incidence of AKP and painless noise at 2-year follow-up. We failed to find any correlation with patellofemoral overstuffing, patellar displacement, or patellar tilt with clinical outcomes. We recommend the use of 3 Merchant views to fully evaluate the patellofemoral joint.

Optimization of sagittal and coronal planes with robotic-assisted unicompartmental knee arthroplasty.

BACKGROUND: One of the anatomic goals of total knee arthroplasty (TKA) is optimizing in the coronal and sagittal plane. Accurate alignments of both planes have been correlated to functional outcome and range of motion. There is a paucity of evidence on the accuracy of unicompartmental knee arthroplasty (UKA) in balancing biplanar knee alignment - specifically sagittal plane alignment. Because robotic assisted UKA has an advantage of more accurately manipulating sagittal plane for optimal alignment and kinematics based on pre-operative and intraoperative CT planning we assessed the accuracy. METHODS: We reviewed the clinical and radiographic information of 94 robotic assisted UKA surgeries for balancing of sagittal and coronal knee anatomy using radiographic parameters, such as posterior condylar offset ratio (PCOR), posterior tibial slope (PTS), femoral-tibial angle, and joint line. RESULTS: In the sagittal plane, we found no significant difference between pre and postoperative PCOR values. As planned, PTS was significantly lower after UKA compared to the native knee (4.91° vs 2.28°; p<0.0001). In the coronal plane, there was no significant difference in the joint line however pre and post-operative mechanical axis were significantly different (5.43°±2.58 of varus vs. 2.76°±2.14 of varus; p<0.0001). CONCLUSION: This study attempts to quantify sagittal and coronal plane alignment after robotic assisted UKA. More attention should be paid to the role of sagittal plane alignment after UKA. We believe modifying posterior tibial slope, while maintaining PCOR is fundamental in achieving native kinematics and optimizing range of motion in the sagittal plane. This may be best-accomplished using robotic techniques for UKA.

Structural changes induced by L50P and I61T single mutations of ubiquitin affect cell cycle progression while impairing its regulatory and degradative functions in Saccharomyces cerevisiae.

Posttranslational conjugation of ubiquitin to proteins either regulates their function directly or concentration through ubiquitination dependent degradation. High degree of conservation of ubiquitin's sequence implies structural and functional importance of the conserved residues. Ubiquitin gene of Saccharomyces cerevisiae was evolved in vitro by us to study the significance of conserved residues. Present study investigates the structural changes in the protein resulting from the single mutations UbS20F, UbA46S, UbL50P, UbI61T and their functional consequences in the SUB60 strain of S. cerevisiae. Expression of UbL50P and UbI61T decreased Cdc28 protein kinase, enhanced Fus3 levels, caused dosage dependent lethality and at sublethal level produced drastic effects on stress tolerance, protein sorting, protein degradation by ubiquitin fusion degradation pathway and by lysosomes. UbS20F and UbA46S produced insignificant effects over the cells. All four mutations of ubiquitin were incorporated into polyubiquitin. However, polyubiquitination with K63 linkage decreased significantly in cells expressing UbL50P and UbI61T. Structural studies on UbL50P and UbI61T revealed distorted structure with greatly reduced α-helical and elevated ß-sheet contents, while UbS20F and UbA46S show mild structural alterations. Our results on functional efficacy of ubiquitin in relation to structural integrity may be useful for designing inhibitors to investigate and modulate eukaryotic cellular dynamics.

Q2N and E64G double mutation of ubiquitin confers a stress sensitive phenotype on Saccharomyces cerevisiae.

The eukaryotic protein, ubiquitin harbours a parallel ß-bulge in its structure which is formed by residues Glu64(1), Ser65(2) and Gln2(X). Despite their low % frequency of occurrence in parallel ß-bulges, the residues Gln2 and Glu64 have been totally conserved in ubiquitin. In a previous study, two single mutants UbQ2N and UbE64G were constructed by replacing the residues Gln2 and Glu64 with Asn and Gly, respectively to understand their importance. The choice of the residues for substitution was made on the basis of their high preference for existence in parallel ß-bulge, so that the structure of mutants remains unaltered and any functional differences observed would highlight the importance of Gln2 and Glu64 in ubiquitin biology. The results from this study established that yeast cells expressing either UbQ2N or UbE64G, displayed functional differences with respect to survival upon exposure to cycloheximide and degradation of substrates by ubiquitin fusion degradation (UFD) pathway. It describes construction of the double mutant UbQ2N-E64G and its characterization. Our results showed expression of UbQ2N-E64G in stress hypersensitive SUB60 cells led to significant decrease in growth rate and prolonged half-life of substrates of UFD pathway, besides failure of complementation under heat and antibiotic stresses, providing the reason for conservation of Gln2 and Glu64 in ubiquitin sequence.

Short term results of cementless total hip arthroplasty in sicklers.

BACKGROUND: Sickle cell (SC) disease leading to endarteritis induces skeletal changes in the form of osteitis, sclerosis of femoral canal and osteonecrosis of the femoral head. All these make total hip arthroplasty (THA) difficult and prolonged. There is increased risk of infection, SC crisis and increased complication rate. Our paper aims to highlight preoperative, intraoperative and postoperative hurdles encountered in performing THA in sicklers and the short term outcome using cementless implants. MATERIALS AND METHODS: Thirty-nine patients with SC disease, who had osteonecrosis of the femoral head, were operated between 2007 and 2011. The mean age of patients was 22 years (range 13-49 years). There were twenty eight females and 11 males. Bilateral cementless total hip replacement (THR) was performed in 11 patients (22 hips) and in the rest unilateral (28 hips). Preoperative and postoperative modified Harris hip score was evaluated. The average followup was 3.8 years (range 2-6 years). RESULTS: The average operating time was 96 min (range 88-148 min). The average blood loss was 880 ml (range 650-1200 ml). The average intraoperative blood transfused was 2.3 units (range 2-5 units). All patients showed an improvement in Harris hip score from 42 points preoperatively to 92 points at latest followup. Intraoperatively, one patient had a periprosthetic fracture. Six patients developed acute SC crisis and were managed in intensive care unit. Three patients developed wound hematoma. Three patients developed limb length discrepancy less than 1 cm. None had early or late dislocations, infection, heterotopic ossification, sciatic nerve palsy and aseptic loosening. CONCLUSION: THA in sicklers involves considerable challenge for the orthopedic surgeon. Management requires a multidisciplinary approach involving the anesthetist, hematologist and the orthopedic surgeon. Contrary to previous reports, THA in sicklers now has a predictable outcome especially with the use of cementless implants.

Functional characterization of dosage-dependent lethal mutation of ubiquitin in Saccharomyces cerevisiae.

Ubiquitin is a eukaryotic protein with 96% sequence conservation from yeast to human. Ubiquitin plays a central role in protein homeostasis and regulation of protein function. We have reported on the generation of variants of ubiquitin by in vitro evolution in Saccharomyces cerevisiae to advance our understanding of the role of the invariant amino acid residues of ubiquitin in relation to its function. One of the mutants generated, namely UbEP42, was a dosage-dependent lethal form of the ubiquitin gene, causing lethality to UBI4-deficient cells but not to ubiquitin wild-type cells. In the present study we investigated the functional reasons for the observed lethality. Expression of UbEP42 in a UBI4-deleted stress-sensitive strain resulted in an increased generation time due to a delayed S phase caused by decreased levels of Cdc28 protein kinase. Cells expressing UbEP42 displayed heightened sensitivity towards heat stress and exposure to cycloheximide. Furthermore, its expression had a negative effect on the degradation of substrates of the ubiquitin fusion degradation pathway. However, UbEP42 is incorporated into polyubiquitin chains. Collectively, our results establish that the effects seen with the mutant ubiquitin protein UbEP42 are not due to malfunction at the stage of polyubiquitination.

Autograft reconstructions for bone defects in primary total knee replacement in severe varus knees.

BACKGROUND: Large posteromedial defects encountered in severe varus knees during primary total knee arthroplasty can be treated by cementoplasty, structural bone grafts or metallic wedges. The option is selected depending upon the size of the defect. We studied the outcome of autograft (structural and impaction bone grafting) reconstruction of medial tibial bone defects encountered during primary total knee replacement in severe varus knees. MATERIALS AND METHODS: Out of 675 primary varus knees operated, bone defects in proximal tibia were encountered in 54 knees. Posteromedial defects involving 25-40% of the tibial condyle cut surface and measuring more than 5 mm in depth were grafted using a structural graft obtained from cut distal femur or proximal tibia in 48 knees. For larger, peripheral uncontained vertical defects in six cases, measuring >25 mm in depth and involving >40% cut surface of proximal tibial condyle, impaction bone grafting with a mesh support was used. RESULTS: Bone grafts incorporated in 54 knees in 6 months. There was no graft collapse or stress fractures, loosening or nonunion. The average followup period was 7.8 years (range 5-10 years). We observed an average postoperative increase in the Knee Society Score from 40 to 90 points. There was improvement in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores in terms of pain, stiffness and physical function during activities of daily living. CONCLUSION: Bone grafting for defects in primary total knee is justified as it is biological, available then and is cost effective besides preserving bone stock for future revisions. Structural grafts should be used in defects >5 mm deep and involving 25-40% of the cut proximal tibial condyle surface. For larger peripheral vertical defects, impaction bone grafting contained in a mesh should be done.

Bioball universal modular neck adapter as a salvage for failed revision total hip arthroplasty.

Management of recurrent dislocation of total hip arthroplasty is often a challenging and daunting task. Re-revision of such a total hip prosthesis may not be easy as the removal of a well-fixed, fully coated stem is extremely difficult. We managed to salvage instability in three revision hip cases in which the fully coated stem had subsided by using a bioball universal neck adapter without changing the femoral stem or acetabular cup.

Sideswipe injuries around the elbow: Management and functional evaluation.

INTRODUCTION: Sideswipe injuries constitute a subgroup of complex elbow trauma. Almost all of these are high energy open injuries. There is no fixed protocol that is followed in the earlier studies. The injury pattern is grotesque and ill managed with poor functional outcome. We report the functional outcome in our series of patients who sustained sideswipe injuries. MATERIALS AND METHODS: Thirty four patients presenting with sideswipe injuries around the elbow were managed and functional results evaluated. The patients were followed for 15-94 months (mean 74 months). 32 of these were males and two were females. The injuries were sustained between 8 years and 48 years age group (mean 30 years). The right side was affected in 20 and left side was injured in 14 patients. Road traffic accident was the cause in all patients. Principles of management followed were (1) debridement and stabilization of fractures, (2) vascular repair, (3) redebridement, (4) nerve repair and (5) soft tissue cover. An external fixator was used for fracture stabilization in 20 patients with open fractures. Internal fixation was used as a stabilization modality in 12 patients. Primary nerve repair was carried out in 4 cases. In case of segmental loss, tendon transfers or nerve grafting was carried out at a later date once softtissue healing was complete. Soft tissue coverage was provided within 24-48 h of injury. Results were evaluated using the Mayo elbow performance score. RESULTS: The average Mayo elbow performance score was 70. Excellent results (score > 90) in accordance with Mayo elbow score were seen in 30% of the patients. Good results (score 75-89) were seen in 33% of the patients. CONCLUSION: Sideswipe injuries should be managed timely, aggressively and an algorithmic protocol should be followed to achieve best results. The injury pattern is distinct for which a multispecialty approach is needed and an orthopedic, vascular and plastic surgeon must be involved. Limb salvage is possible in most cases.

A rare case of open bicondylar Hoffa fracture with extensor mechanism disruption.

The incidence of open bicondylar Hoffa fractures is extremely rare. We report one such case of a 42-year-old woman who presented to the emergency department with an open injury over the knee. Imaging revealed bicondylar Hoffa fracture. The patient was taken up for debridement and internal fixation. Intraoperative findings included an entrapped patella between the fracture fragments and extensor mechanism disruption. Hoffas fracture was fixed with lag screws and patellar tendon repaired on to the inferior patella. The patient was started on early postoperative range of motion exercises. The fracture united at 12 weeks with 120° knee flexion at 2 year follow-up.

Anterior cruciate ligament reconstruction using the medial third of the patellar tendon.

PURPOSE: To evaluate the mid-term outcome of anterior cruciate ligament (ACL) reconstruction using the medial third of the patellar tendon as the bone-patellar tendon-bone (BPTB) graft. METHODS: 79 men (34 right knees and 45 left knees) aged 20 to 52 (mean, 28) years underwent ACL reconstruction using the medial third of the patellar tendon with bone plugs and were followed up for a minimum of 3 years. Stability was assessed using the Lachman test and the pivot shift test. The range of motion, donor-site symptoms, Lysholm knee score, and International Knee Documentation Committee (IKDC) score were also recorded. RESULTS: In terms of stability, only 4 patients had a grade-2 laxity postoperatively, compared to all having a grade-2 or -3 laxity preoperatively. Regarding the range of motion, extension loss was <3º in 76 patients and 3º to 5º in 3, whereas flexion loss was <5º in 73 patients, 5º to 15º in 5, and 16º to 25º in one. No patient had patellar tendon rupture/shortening, patellar fracture, or patellar maltracking. The mean Lysholm knee score improved from 48 to 92 (p<0.0001); scores were excellent (>90) in 46 patients and good (83-90) in 32 patients. The overall IKDC score was grade A (normal) in 9 patients, grade B (near normal) in 66, and grade C (abnormal) in 4. Three of the latter patients had osteoarthritic changes and pain on minimal physical activity. Only one patient had a sensation of partial giving way during moderate physical activity. 20% of the patients had anterior knee pain. CONCLUSION: Outcome of ACL reconstruction using the medial third of the patellar tendon was comparable to that using the central third of the patellar tendon. In addition, there were no instances of patellar tendon rupture/shortening, patellar fracture, or patellar maltracking.

Neglected, locked, obturator type of inferior hip dislocation treated by total hip arthroplasty.

Neglected dislocations of the hip are uncommon and open reduction is usually followed by avascular necrosis and subsequent coxarthrosis. We present a rare case of neglected, locked, obturator type of inferior hip dislocation in a young adult presenting 6 months after initial trauma treated with a cementless total hip arthroplasty which, to the best of our knowledge, has not been reported previously. Technical aspects of total hip arthroplasty and other treatment options in this scenario are discussed.

Construction and functional characterization of double and triple mutants of parallel beta-bulge of ubiquitin.

Ubiquitin, a small eukaryotic protein serving as a post-translational modification on many important proteins, plays central role in cellular homeostasis and cell cycle regulation. Ubiquitin features two beta-bulges, the second beta-bulge, located at the C-terminal region of the protein along with type II turn, holds 3 residues Glu64(1), Ser65(2) and Gln2(X). Percent frequency of occurrence of such a sequence in parallel beta-bulge is very low. However, the sequence and structure have been conserved in ubiquitin through out the evolution. Present study involves replacement of residues in unusual beta-bulge of ubiquitin by introducing mutations in combination through site directed mutagenesis, generating double and triple mutants and their functional characterization. Mutant ubiquitins cloned in yeast expression vector YEp96 tested for growth profile, viability assay and heat stress complementation study have revealed significant decrease in growth rate, loss of viability and non-complementation of heat sensitive phenotype with UbE64G-S65D and UbQ2N-E64G-S65D mutations. However, UbQ2N-S65D did not show any negative effects in the above assays. Present results show that, replacement of residues in beta-bulge of ubiquitin exerts severe effects on growth and viability in Saccharomyces cerevisiae due to functional failure of the mutant ubiquitins UbE64G-S65D and UbQ2N-E64G-S65D.